Damping device, cab and method for optimizing fatigue life and lightweight of the cab

Abstract

The application discloses a damping device, a cab and a fatigue life and lightweight collaborative optimization method thereof, the damping device comprising a first damping unit, the first damping unit comprising a protective net, a fixed plate, a base, a guide element, a first elastic element and a limiting element; the fixed plate is arranged opposite to the base and is connected with the protective net; the guide element is located between the fixed plate and the base and is arranged opposite to the base, a movement space is formed between the guide element and the base, and the base is used for being connected with a cab body; the first elastic element is arranged in the movement space; one end of the limiting element is connected with the base, and the other end of the limiting element is matched with the fixed plate to limit the stroke of the first elastic element. The application can effectively reduce the vibration of the cab, solve the comfort and vibration fatigue failure problems of the driver, and realize the lightest total mass of the cab under the condition that the fatigue life of the cab meets the standard.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of engineering machinery, and particularly relates to a damping device, a cab and a fatigue life and lightweight collaborative optimization method thereof. BACKGROUND

[0002] Engineering machinery operation is often accompanied by large impact and strong vibration, causing large vibration of the cab floor and seat, and leading to a sharp deterioration of the comfort of the driver. At the same time, it causes cracking of the skeleton splicing, thin plate structure and other structures, and the vibration fatigue failure problem is highlighted. In order to solve the driver's comfort and vibration fatigue failure problem, a damper is generally installed at the bottom of the cab to filter the vibration from the engine and the working device. However, due to its inherent characteristics, the damper has poor vibration isolation effect in the low frequency region.

[0003] In the Chinese patent application No. 201911280029.9, a cab skeleton, a cab and a excavator are disclosed, which are composed of a cab main skeleton, a cab right lower cover, a right cover, a front upper cover, a top cover, a rear cover and a left cover. The cab main skeleton is welded into a closed structure by metal profiled material, rectangular tube and reinforcing rib, and has stable, simple and high strength structure. This scheme has three common problems, (1) the design redundancy of the cab structure is large, which causes it to be too heavy, high production cost and low economic efficiency. (2) Only the structure static fatigue is considered, and the dynamic fatigue life is not considered, which is easy to cause stress concentration in local position and easy to crack failure. (3) The reinforcing rib is mostly straight plate or bent plate, and the structure is simple and the reinforcing effect is limited.

[0004] In the Chinese patent application No. 202010837510.X, a combined power absorber optimization method, system, terminal device and storage medium are disclosed, which include: establishing a combined power absorber model provided with the same number and type of power absorbers; simulating and analyzing the main system amplitude frequency response results of five combination modes according to the four parameters of power absorber mass, stiffness, damping and damping rate under the same optimization constraint condition; obtaining the optimal combination mode in the five combination modes based on the minimum value minimization principle of the maximum power amplification coefficient of the main system; obtaining the optimized spring stiffness of each power absorber according to the optimal combination mode; selecting the optimized power absorber corresponding to the optimized spring stiffness. This scheme obtains the optimized stiffness of each absorber based on the minimum value minimization principle of the maximum power amplification coefficient of the main system, and the arrangement of large size or multiple small size absorbers will affect the cab space and weight. It can be seen that this scheme still cannot solve the driver's comfort and vibration fatigue failure problem.

[0005] Therefore, a new damping device is designed and arranged at a reasonable position of the cab to effectively reduce the vibration of the cab. In addition, a dynamic fatigue life and lightweight collaborative optimization method suitable for the cab is proposed, so that the fatigue life of the cab meets the standard and the weight of the cab is optimized. It becomes a problem to be solved. SUMMARY

[0006] In view of the above problems, the present application provides a damping device, a cab and a fatigue life and lightweight collaborative optimization method suitable for the cab, which can effectively reduce the vibration of the cab and solve the comfort and vibration fatigue failure problems of the driver.

[0007] In order to achieve the above technical purpose and achieve the above technical effect, the present application realizes the following technical scheme:

[0008] In the first aspect, the present application provides a damping device suitable for a cab, which comprises a first damping unit, the first damping unit comprising a protective net, a fixed plate, a base, a guide element, a first elastic element and a limiting element;

[0009] The fixed plate is arranged opposite to the base and connected with the protective net;

[0010] The guide element is located between the fixed plate and the base and arranged opposite to the base, and forms a movement space between the guide element and the base, and the base is further used to connect with the cab body;

[0011] The first elastic element is arranged in the movement space;

[0012] One end of the limiting element is connected with the base, and the other end cooperates with the fixed plate to limit the stroke of the first elastic element.

[0013] Optionally, the limiting element comprises a limiting cylinder and a limiting plate, and the guide element comprises a guide rod and a guide plate;

[0014] One end of the limiting cylinder is connected with the base, and the other end cooperates with the fixed plate to limit the stroke of the first elastic element;

[0015] The limiting plate is an elastic body, connected with the fixed plate, and the limiting plate can reciprocate in the limiting cylinder;

[0016] The guide plate is arranged opposite to the base, and forms a movement space between the guide plate and the base;

[0017] One end of the guide rod is connected with the base, and the other end penetrates the guide plate, the limiting plate and the fixed plate in sequence, and the guide plate, the limiting plate and the fixed plate can reciprocate along the guide rod.

[0018] Optionally, the first elastic element is a spiral spring body or a rubber spring body.

[0019] The rubber spring body comprises an inner metal ring body, a rubber outer ring body and a boss rubber structure.

[0020] The inner metal ring body has a hollow structure.

[0021] The rubber outer ring body is arranged outside the inner metal ring body and is connected to the inner metal ring body through the boss rubber structure.

[0022] Optionally, at one end of the rubber spring body, the end of the rubber outer ring body is higher than the ends of the boss rubber structure and the inner metal ring body, and the end of the inner metal ring body is higher than the end of the boss rubber structure; at the other end of the rubber spring body, the end of the inner metal ring body is higher than the ends of the rubber outer ring body and the boss rubber structure.

[0023] Optionally, the outer diameter of the inner metal ring body is 1 / 3-2 / 3 of the diameter of the rubber spring body, the thickness of the rubber outer ring body is 1 / 10-1 / 3 of the diameter of the rubber spring body, and the diameter of the boss rubber structure is greater than or equal to 1 / 10 of the diameter of the rubber spring body.

[0024] Optionally, the first damping unit further comprises a damping element, which is a damping rod or a granular damping material; the granular damping material is arranged in a closed space formed between the rubber spring body and the guide plate.

[0025] Optionally, the frequency modulation ratio of the first damping unit is 0.85-0.95.

[0026] Optionally, the damping device further comprises a second damping unit; the second damping unit comprises a fixed frame, a combined mass block and a second elastic element.

[0027] The combined mass block is installed in the fixed frame and comprises a mass block fixing frame and a plurality of sub-mass blocks connected to the mass block fixing frame, the number and shape of the sub-mass blocks being determined by the vibration frequency to be eliminated.

[0028] The second elastic element is arranged between the fixed frame and the combined mass block, has stiffness and damping characteristics, and has two directions of freedom.

[0029] Optionally, the frequency modulation ratio of the second elastic element is 0.90-0.97.

[0030] In a second aspect, the present application provides a cab comprising the damping device of any one of the first aspect.

[0031] In a third aspect, the application provides a fatigue life and lightweight collaborative optimization method for a cab, comprising:

[0032] taking the thickness of the elements in the cab body that meet the preset conditions as the key design variables;

[0033] taking the original thickness of each element that meets the preset conditions before optimization and the minimum thickness that meets the fatigue life index as the feasible region;

[0034] interpolating in the feasible region to obtain the optimal combination of the key design variables, with the fatigue life of the cab assembly and the total weight of the cab assembly as the collaborative optimization objectives, and the performance of the cab assembly after optimization being better than or equal to the performance of the cab assembly before optimization as the constraint condition; the cab assembly comprises the cab body and the vibration damping device according to any one of claims 1-9.

[0035] Optionally, the step of taking the elements in the cab body that meet the preset conditions as the key design variables comprises the following steps:

[0036] obtaining the preset elements to be optimized;

[0037] selecting the elements to be optimized whose weight-to-total mass ratio of the cab assembly is greater than a set threshold, and grouping the elements to be optimized whose thickness difference is less than a set threshold to form a plurality of combinations;

[0038] based on the finite element grid model of the cab assembly before optimization, calculating the fatigue life of each combination corresponding to different thicknesses by reducing the thickness of the elements to be optimized in a combination, and further calculating the sensitivity between each combination and the fatigue life of the cab assembly;

[0039] deleting the combinations with a sensitivity greater than a set threshold, and taking the thickness of the elements to be optimized in the remaining combinations as the key design variables.

[0040] Optionally, the minimum thickness that meets the fatigue life index is obtained by the following steps:

[0041] based on the finite element grid model of the cab assembly before optimization, obtaining the minimum thickness of the elements to be optimized in the remaining combinations that meet the fatigue life requirement through fatigue life simulation calculation.

[0042] Optionally, the step of interpolating in the feasible region to obtain the optimal combination of the key design variables, with the fatigue life of the cab assembly and the total weight of the cab assembly as the collaborative optimization objectives, and the performance of the cab assembly after optimization being better than or equal to the performance of the cab assembly before optimization as the constraint condition, comprises the following steps:

[0043] The number of each combination and the plate thickness of the element to be optimized in each combination are taken as two-dimensional coordinates of a feasible region, interpolation is performed in the feasible region by using a preset interpolation method, and a plurality of schemes are obtained, and the expression of each scheme is: (the number of the combination, the plate thickness of the element to be optimized in the combination);

[0044] Fatigue life simulation calculation is performed for each optimization scheme, and based on the fatigue life simulation calculation results, combinations that meet the fatigue life requirement and the plate thickness corresponding to each combination are selected;

[0045] Based on the selected combinations and the plate thickness corresponding to each combination, the total mass of the cab assembly after optimization is calculated, and the smallest total mass of the cab assembly is selected;

[0046] If the difference between the smallest total mass of the cab assembly after optimization and the target total mass of the cab assembly is less than a preset value, the plate thickness corresponding to the selected combination is taken as the optimal combination.

[0047] Optionally, the smallest total mass of the cab assembly is obtained by using the following formula:

[0048] minf(x)=min{f Ⅰ (x),f Ⅱ (x),f Ⅲ (x),f Ⅳ (x),f Ⅴ (x),…,f k (x)}+f C

[0049] x=[x I ,x II ,x III ,x IV ,x V ,…x k ] T

[0050] Wherein, x is a key design variable, x=[x I ,x II ,x III ,x IV ,x V ,…x k ] T is a variable space; I, II, III, IV, V… are the numbers of the selected combinations; f(x) is the total mass of the cab assembly after optimization; f k (x) is the mass of each selected combination; f C is the remaining value obtained by subtracting the original mass of all selected elements to be optimized from the total mass of the cab assembly.

[0051] Optionally, before the step of taking the number of each combination and the plate thickness of the element to be optimized in each combination as the two-dimensional coordinates of the feasible region, the method further comprises the steps of:

[0052] Taking the number of each combination and the plate thickness of the element to be optimized in each combination as the two-dimensional coordinates of the feasible region, the total mass of the cab assembly corresponding to each combination under different plate thicknesses is calculated.

[0053] Taking the calculated total mass of the cab assembly should be less than the target total mass of the cab assembly as the judgment basis, the combinations that do not meet the judgment basis and the plate thickness corresponding to the combinations are excluded.

[0054] Compared with the prior art, the beneficial effects of the present application are:

[0055] The present application proposes a first damping unit for vibration absorption of the protective net, and proposes the layout relationship (i.e. the mounting relationship) of the first damping unit with the protective net and the cab, which can not only avoid the occupation of the cab space by the first damping unit, but also eliminate the low-frequency vibration transmitted from the vibration source to the cab and the driver.

[0056] Further, the present application also proposes a second damping unit special for the seat which can eliminate two-way vibration, and proposes the optimal layout of the vibration absorber in the cab, which can not only avoid the occupation of the cab space by the first damping unit, but also eliminate the low-frequency vibration transmitted from the vibration source to the cab and the driver.

[0057] The present application proposes a fatigue life and lightweight collaborative optimization method suitable for the cab, which realizes the minimization of the total weight of the cab under the premise of ensuring the fatigue life of the cab by designing the plate thickness of the element to be optimized in the cab body. BRIEF DESCRIPTION OF DRAWINGS

[0058] In order to make the content of the present application easier to be clearly understood, the present application will be further described in detail below according to specific embodiments and in combination with the drawings, in which:

[0059] Figure 1 It is a three-dimensional structure diagram of the cab assembly of a certain type of engineering machinery;

[0060] Figure 2 It is a three-dimensional structure diagram of the cab body framework of a certain type of engineering machinery;

[0061] Figure 3 It is a three-dimensional view of a first damping unit of a certain type using a helical spring body as a first elastic member;

[0062] Figure 4 It is a sectional view of a first damping unit of a certain type using a helical spring body as a first elastic member;

[0063] Figure 5A three-dimensional view of a first damping unit of a certain type using a rubber spring body as a first elastic element;

[0064] Figure 6 A sectional view of a first damping unit of a certain type using a rubber spring body as a first elastic element;

[0065] Figure 7 is a three-dimensional view of a certain rubber spring body;

[0066] Figure 8 A three-dimensional view of a second damping unit of a certain type;

[0067] Figure 9 An exploded view of a second damping unit of a certain type;

[0068] Figure 10 A flowchart of a certain collaborative optimization method;

[0069] Wherein:

[0070] 1 cab assembly, 2 cab body, 3 front lower protective net, 4 front upper protective net, 5 top protective net, 6 first elastic element, 6-1 helical spring body, 6-2 rubber spring body, 6-2-1 inner metal ring body, 6-2-2 boss rubber structure, 6-2-3 rubber outer ring body, 7 guide element, 7-1 guide plate, 7-2 guide rod, 8 limiting element, 8-1 limiting cylinder, 8-2 limiting plate, 9 first damping unit, 10 base, 11 fixed plate, 12 second damping unit, 12-1 fixed frame, 12-2 second elastic element, 12-3 combined mass block, 12-3-1 mass block fixing frame, 12-3-2 distributed mass block, 12-4 cover, 13 rear upright column, 14 seat support, 15 rear wall rectangular tube, 16 front left A column profile, 17 front right A column profile, 18 top left wing main skeleton profile, 19 top right wing main skeleton profile, 20 top rectangular tube, 21 front bottom plate rectangular tube. DETAILED DESCRIPTION

[0071] In order to make the purpose, technical scheme and advantages of the present application clearer and more comprehensible, the present application will be further described in detail below in combination with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the protection scope of the present application.

[0072] The application principle of the present application will be described in detail below in combination with the drawings.

[0073] Example 1

[0074] A damping device suitable for a cab is provided in the embodiments of the present application, such as Figures 3-6As shown, the first damping unit 9 comprises a protective net, a guide element 7, a base 10, a first elastic element 6, a limiting element 8 and a fixing plate 11;

[0075] The fixing plate 11 is arranged opposite to the base 10, and the fixing plate 11 is connected with the protective net;

[0076] The guide element 7 is located between the fixing plate 11 and the base 10, and is arranged opposite to the base 10, and forms a movement space between the guide element 7 and the base 10, and the base 10 is further used for being connected with the cab;

[0077] The first elastic element 6 is arranged in the movement space;

[0078] One end of the limiting element 8 is connected with the base 10, and the other end cooperates with the fixing plate 11 to limit the stroke of the first elastic element 6.

[0079] In the embodiment of the present application, the first damping unit for absorbing vibration of the protective net is provided, and the first damping unit is arranged between the protective net and the cab, that is, the layout relationship between the first damping unit, the protective net and the cab is limited, so that the first damping unit can not occupy the space of the cab body, and the low-frequency vibration transmitted from the vibration source (such as an engine) to the cab body and the driver can be eliminated.

[0080] In one specific embodiment of the embodiment of the present application, the frequency modulation ratio of the first damping unit 9 is 0.85-0.95. In actual application, the mass of the protective net is mainly adjusted, and the stiffness parameter of the first elastic element 6 is adjusted as a supplement, so as to change the frequency modulation ratio of the first damping unit 9.

[0081] In one specific embodiment of the embodiment of the present application, the first damping unit 9 is called a protective net dynamic vibration absorber, and the number of the first damping unit 9 can be set to three, and each first damping unit 9 is arranged between the cab body 2 and the front lower protective net 3, the front upper protective net 4 and the top protective net 5, so that the front lower protective net 3, the front upper protective net 4 and the top protective net 5 can move along the single or multiple freedom directions, and the low-frequency vibration of the cab in the specified direction is eliminated.

[0082] In one specific embodiment of the embodiment of the present application, the limiting element 8 comprises a limiting cylinder 8-1 and a limiting plate 8-2; and the guide element 7 comprises a guide rod 7-2 and a guide plate 7-1;

[0083] One end of the limiting cylinder 8-1 is connected with the base 10, and the other end cooperates with the fixed plate 11 to limit the stroke of the first elastic element 6, preferably, the distance between the other end of the limiting cylinder 8-1 and the fixed plate 11 is 5-20 mm, that is, the movement stroke of the limiting element 8 is 5-20 mm, so as to ensure that the protective net can move in a small stroke (such as 5-20 mm) and realize the vibration absorption function;

[0084] The limiting plate 8-2 is an elastic body, which is connected with the fixed plate 11, and can reciprocate in the limiting cylinder 8-1;

[0085] The guide plate 7-1 is arranged opposite to the base 10, and a movement space is formed between the two;

[0086] One end of the guide rod 7-2 is connected with the base 10, and the other end penetrates the guide plate 7-1, the limiting plate 8-2 and the fixed plate 11 in sequence, and the guide plate 7-1, the limiting plate 8-2 and the fixed plate 11 can reciprocate along the guide rod 7-2; in the specific implementation process, the base 10 is an inner threaded base, which is threadedly connected with one end of the guide rod 7-2;

[0087] When the first damping unit 9 is under pressure or after being under pressure, the first elastic element 6 and the limiting plate 8-2 are adjusted, so that the first elastic element 6 and the limiting plate 8-2 play a vibration absorption role in a reasonable range;

[0088] The guide element 7 is preferably designed to enable the protective net to move in a single degree of freedom direction, wherein the front lower protective net 3 and the first damping unit 9 connected therewith are designed to eliminate the vibration of the cab in the driving direction; and the top protective net 5 and the first damping unit 9 connected therewith are designed to eliminate the vibration of the cab in the vertical direction.

[0089] In one specific embodiment of the embodiment of the application, the first elastic element 6 is a spiral spring body 6-1 (see Figure 3 and 4 ) or a rubber spring body 6-2 (see Figure 5 and 6 ); The rubber spring body comprises an inner metal ring body 6-2-1, a rubber outer ring body 6-2-3 and a boss rubber structure 6-2-2;

[0090] As shown in FIG. 7, the inner metal ring body 6-2-1 is a hollow structure, which is used to accommodate the guide rod 7-2 in the guide element 7, and the guide rod 7-2 is used to fix and constrain the rubber spring body 6-2;

[0091] The rubber outer ring body 6-2-3 is arranged outside the inner metal ring body 6-2-1 and is connected with the inner metal ring body 6-2-1 through the boss rubber structure 6-2-2; in the specific implementation process, the boss rubber structure 6-2-2 and the inner metal ring body 6-2-1 are connected through an adhesive process; in one specific implementation manner of the embodiment of the present application, the inner metal ring body 6-2-1, the boss rubber structure 6-2-2 and the rubber outer ring body 6-2-3 are matched through a layer-by-layer retreat design, specifically, at one end of the rubber spring body 6-2, the end of the rubber outer ring body 6-2-3 is higher than the ends of the boss rubber structure 6-2-2 and the inner metal ring body 6-2-1, and the end of the inner metal ring body 6-2-1 is higher than the end of the boss rubber structure 6-2-2; at the other end of the rubber spring body 6-2, the end of the inner metal ring body 6-2-1 is higher than the ends of the rubber outer ring body 6-2-1 and the boss rubber structure 6-2-2, so that the variable range of the stiffness and damping of the rubber spring body 6-2 is widened. In the specific implementation process, each first damping unit 9 is generally used in cooperation with a damping element (not shown in the figure) to maximize the damping function. The damping element can be a damping rod or a granular damping material; the granular damping material is arranged in a closed space formed by the rubber spring body and a guide plate in the guide element

[0092] In one specific implementation manner of the embodiment of the present application, in order to improve the stiffness and deformation of the rubber spring body, the outer diameter of the inner metal ring body 6-2-1 is 1 / 3-2 / 3 of the diameter of the rubber spring body 6-2, the thickness of the rubber outer ring body 6-2-3 is 1 / 10-1 / 3 of the diameter of the rubber spring body, and the thickness of the boss rubber structure 6-2-2 is greater than or equal to 1 / 10 of the diameter of the rubber spring body 6-2.

[0093] In one specific implementation manner of the embodiment of the present application, the fixing plate 11 is designed as a U-shaped clamp, and the fixing plate 11 is clamped with the protective net through a fixing cylinder. In other embodiments of the embodiment of the present application, the fixing plate 11 can also be designed as other shapes as long as it can be clamped with the protective net.

[0094] Embodiment 2

[0095] Based on embodiment 1, the embodiment of the present application is different from embodiment 1 in that, as shown in Figures 8-9 The damping device further includes a second damping unit 12, and the second damping unit 12 includes a fixed frame 12-1, a second elastic element 12-2, a combined mass block 12-3 and a cover 12-4.

[0096] The combined mass 12-3 comprises a mass fixing frame 12-3-1 and a plurality of sub-masses connected to the mass fixing frame 12-3-1;

[0097] The combined mass 12-3 is installed in the fixed frame 12-1;

[0098] The second elastic element 12-2 is arranged between the fixed frame 12-1 and the combined mass 12-3, has stiffness and damping characteristics, and has 1-2 degrees of freedom, the frequency modulation ratio of the second elastic element is 0.85-0.95, and in actual application, the mass of the combined mass 12-3 is mainly adjusted, and the stiffness parameter of the second elastic element 12-2 is secondarily adjusted to change the frequency modulation ratio of the second damping unit 12;

[0099] The cover 12-4 is wrapped outside the combined mass 12-3.

[0100] In the specific implementation process, the second damping unit 12 is called a seat dynamic vibration absorber, is arranged on the framework of a seat backrest, and is used for eliminating vibration in the vertical backrest direction of the seat, or is fixed between a seat damping suspension and a seat cushion, and is used for eliminating vibration in the up-down direction of the seat.

[0101] Embodiment 3

[0102] The application provides a cab, which comprises the damping device in any one of the embodiments 1 or 2.

[0103] Embodiment 4

[0104] In an embodiment of the application, a collaborative optimization method suitable for a cab is provided, and the method comprises the following steps:

[0105] (1) taking the plate thickness of a to-be-optimized element in the cab body 2 that meets a preset condition as a key design variable;

[0106] (2) taking the original plate thickness of each to-be-optimized element that meets the preset condition before optimization and the minimum plate thickness when the fatigue life index is met as a feasible region;

[0107] (3) taking the fatigue life of the cab assembly and the total weight of the cab assembly as collaborative optimization targets, taking the performance of the cab assembly after optimization being superior to or equal to the performance of the cab assembly before optimization as a constraint condition, interpolating in the feasible region to obtain an optimal combination of each key design variable; the cab assembly 1 comprises the cab body 2 and the damping device 9 in any one of claims 1-8, and specific reference is made to Figure 1 .

[0108] As Figure 2As shown, the frame of the cab body 2 includes a rear upright column 13, a seat support 14, a rear wall rectangular tube 15, a front left A column profile 16, a front right A column profile 17, a top left wing main frame profile 18, a top right wing main frame profile 19, a top rectangular tube 20, and a front floor rectangular tube 21. The cab body 2 further includes a cab floor.

[0109] In one specific embodiment of the present application, the elements in the cab body 2 that meet the preset conditions are taken as the key design variables, including the following steps:

[0110] Obtaining the preset elements to be optimized;

[0111] Selecting the elements to be optimized with a weight to total mass ratio greater than a set threshold value, and grouping the elements to be optimized with a plate thickness difference less than a set threshold value to form a plurality of combinations;

[0112] Based on the finite element grid model of the cab assembly before optimization, the fatigue life of each combination under different plate thicknesses is calculated by reducing the plate thickness of the elements to be optimized in a combination, and the sensitivity between each combination and the fatigue life of the cab assembly is further calculated.

[0113] Deleting the combinations with a sensitivity greater than a set threshold value, and taking the plate thickness of the elements to be optimized in the remaining combinations as the key design variables.

[0114] In one specific embodiment of the present application, the minimum plate thickness when the fatigue life index is met is obtained by the following steps:

[0115] Based on the finite element grid model of the cab assembly before optimization, the minimum plate thickness of the elements to be optimized in the remaining combinations when the fatigue life requirement is met is obtained through fatigue life simulation calculation.

[0116] In one specific embodiment of the present application, the fatigue life of the cab assembly and the total weight of the cab assembly are taken as the collaborative optimization objectives, the performance of the cab assembly after optimization is superior to or equal to the performance of the cab assembly before optimization as the constraint condition, interpolation is performed in the feasible region to obtain the optimal combination of each key design variable, including the following steps:

[0117] Taking the number of each combination and the plate thickness of the elements to be optimized in each combination as the two-dimensional coordinates of the feasible region, a preset interpolation method is used to perform interpolation in the feasible region to obtain a plurality of schemes, and the expression of each scheme is: (the number of the combination, the plate thickness of the elements to be optimized in the combination); in the specific implementation process, the interpolation method includes the nearest neighbor point interpolation method or the linear interpolation triangular net method;

[0118] The fatigue life simulation calculation is respectively carried out for each optimization scheme, and based on the fatigue life simulation calculation result, the combination with fatigue life up to standard and the plate thickness corresponding to each combination are selected;

[0119] Based on the screened combination and the plate thickness corresponding to each combination, the optimized cab assembly total mass is calculated, and the smallest cab assembly total mass is selected, and the calculation formula is as follows:

[0120] minf(x)=min{f Ⅰ (x),f Ⅱ (x),f Ⅲ (x),f Ⅳ (x),f Ⅴ (x),…,f k (x)}+f C

[0121] x=[x I ,x II ,x III ,x IV ,x V ,…x k ] T

[0122] Wherein, x is a key design variable, x=[x I ,x II ,x III ,x IV ,x V ,…x k ] T Is the variable space;I, II, III, IV, V… is the number of the screened combination;f(x) is the optimized cab assembly total mass;f k (x) is the mass of each screened combination;f C Is the remaining value of the cab assembly total mass minus the original mass of all screened optimization elements;

[0123] If the difference between the smallest cab assembly total mass after optimization and the target cab assembly total mass is less than a preset value, the plate thickness corresponding to the screened combination is taken as the optimal combination.

[0124] In one specific embodiment of the embodiment, before the step of taking the number of each combination and the plate thickness of the optimization element in each combination as the two-dimensional coordinates of the feasible region, the following steps are further included:

[0125] Taking the number of each combination and the plate thickness of the optimization element in each combination as the two-dimensional coordinates of the feasible region, the corresponding cab assembly total mass of each combination under different plate thicknesses is calculated;

[0126] The calculated cab assembly total mass should be less than the target cab assembly total mass as the judgment basis, and the combinations not meeting the judgment basis are excluded, and the corresponding plate thickness of the combinations is excluded.

[0127] The collaborative optimization method in the embodiment of the application will be described in detail below in combination with a specific implementation. The collaborative optimization design method, as shown in the figure, specifically includes the following steps: Figure 10

[0128] Step 1: Obtain relevant parameters required for collaborative optimization

[0129] 1) Establish a cab assembly finite element grid model and check the grid quality of the cab assembly finite element grid model. Grid division is performed on the three-dimensional CAD model of the cab assembly to generate the cab assembly finite element grid model.

[0130] The grid quality of the cab assembly finite element grid model is checked. The main parameters involved in the grid quality need to meet Jacobian > 0.5, minimum angle of triangular grid > 20°, and minimum angle of quadrilateral grid > 45°.

[0131] 2) Perform calibration of the cab assembly finite element grid model

[0132] Based on the cab assembly finite element grid model, modal shape and modal frequency simulation values of the cab assembly are obtained by simulation calculation through random vibration method;

[0133] Modal shape and frequency test values of the cab assembly are obtained through free modal test of the cab assembly;

[0134] When the error between the modal frequency simulation value and the frequency test value is less than 10%, it is determined that the cab assembly finite element grid model can be used for fatigue life simulation and basic performance simulation;

[0135] 3) Obtain material properties of each element in the cab assembly to form a material library

[0136] The cab assembly generally includes main frame (welded from metal profile, rectangular tube and reinforcing rib), cover, door and window, seat and other main elements. The main materials of each element are different types of structural steel, tempered glass, adhesive, etc.

[0137] The main material properties of the density, elastic model and Poisson's ratio of the material of each element are obtained.

[0138] 4) Obtain the measured cab assembly load spectrum of the whole machine life cycle, and extract the simulation load spectrum from the measured cab assembly load spectrum.

[0139] The load spectrum of the cab assembly is collected in the user's site or test field, including vibration and stress signals.​

[0140] According to the design target life of the cab assembly, the proportion of each working condition in the whole life cycle, the safety factor of the load spectrum (generally 1-2) is set, and based on the cumulative damage equivalent principle, the synthesis and equivalent compression of the time domain load spectrum of the cab assembly are completed, and the time domain six-degree-of-freedom vibration load spectrum of the cab assembly, i.e. the measured cab assembly load spectrum, is output.

[0141] The time domain six-degree-of-freedom vibration load spectrum of the cab assembly is converted into a time domain six-degree-of-freedom force spectrum by using virtual MAST software or virtual load iteration technology, which is used as the simulation load spectrum of the cab assembly fatigue life (i.e. extracting the simulation load spectrum from the measured cab assembly load spectrum).

[0142] The measured cab assembly load spectrum is applied to the cab assembly to obtain the measured vibration signal.

[0143] The simulation load spectrum is applied to the finite element grid model of the cab assembly to generate a simulation vibration signal, and the measured vibration signal is compared with the simulation vibration signal. When the iteration recurrence accuracy of the simulation vibration signal is greater than 85%, the simulation load spectrum is determined to be effective.

[0144] Step 2: Improve the fatigue life simulation of the cab assembly and the basic performance analysis

[0145] 5) Fatigue life simulation calculation pre-processing and solver setting.

[0146] Import the finite element grid model of the cab assembly.

[0147] Map the material properties of each element of the cab assembly to the elements in the finite element grid model of the cab assembly, i.e. connect the solver and the material library.

[0148] Define the simulation load spectrum input and load the simulation load spectrum to the loading point in the finite element grid model of the cab assembly.

[0149] Set the connection relationship of each element in the finite element grid model of the cab assembly. The connection relationship between each element of the cab assembly includes welding, bolting, hinging, gluing and fixed connection, etc. For example: the welding relationship between two elements is connected by shell element, element 1 and element 2 share nodes with weld joint. REB2 is used to simulate bolt connection. SEAM is used to simulate the connection mode of glass, tight contact plate.

[0150] Set up event handling method, preferably using fast superposition method or complete superposition method. Set up stress combination method, preferentially using critical plane method; set up multi-axial stress evaluation method, preferably Auto method, wherein the first stage uses the principal stress (Abs MaxPrincipal) for standard evaluation, and the second stage adjusts the combination method according to the results of the first stage, preferably rain flow count method (Rain flow count) to calculate fatigue life. Set up stress gradient correction, activate stress gradient correction, preferentially use FKM method to evaluate the influence of stress gradient, further select the specified stress gradient correction method, and complete the design of the solver.

[0151] 6) Develop improved cab assembly vibration fatigue life simulation and model verification.

[0152] Based on the set cab assembly finite element grid model and the solver, develop cab assembly time domain fatigue life simulation analysis and post-processing, click operation.

[0153] Develop cab assembly fatigue life simulation verification. Adopt the corresponding bench test fatigue life results to correct the simulation parameters (i.e. the parameters of the cab assembly finite element grid model and the solver), including but not limited to material S-N curve, survival rate, load spectrum safety factor, etc. Ensure that the cab assembly fatigue life simulation results meet the accuracy requirements. When the error between the cab assembly fatigue life simulation results and the bench test life is less than 15%, the fatigue life simulation results are effective and can be used for data analysis and simulation optimization.

[0154] 7) Develop improved cab assembly basic performance analysis

[0155] Simulate and analyze the key basic performance of the cab assembly before improvement, including structural static strength, etc. Use its indicators as constraint conditions, and require that the above basic performance parameters of the improved cab assembly cannot be lower than the pre-improvement level.

[0156] Step 3: Set the fatigue life and lightweight co-optimization target of the cab assembly, determine the key design variables and feasible region, and perform parameter optimization calculation

[0157] 8) Set the initial design target of the cab assembly fatigue life and lightweight

[0158] Based on the fatigue life and total mass of the cab assembly before improvement, combine the benchmark indicators and design experience, and preliminarily determine the reasonable optimization target of the cab assembly.

[0159] 9) Determine the key design variables and their feasible region

[0160] ① The optimization object is set to be the cab body main skeleton (welded by metal profile, rectangular tube and reinforcing rib, etc.), cover, door and window, etc. self-made parts, excluding air conditioning system and other external parts; note that the optimization object in the embodiment of the application includes but is not limited to cab floor, rear left and right stand column, front left and right A column, top left and right wing main skeleton, rear cross beam (upper, middle and lower), seat support, door and various cover parts, etc.

[0161] ② In the selected optimization object range, all elements with a weight greater than 2% of the total mass of the cab assembly are selected, and elements with the same or similar thickness are grouped into a group, divided into several combinations, and each combination is numbered as I, II, III, ….

[0162] ③ In the improved cab assembly simulation model, the thickness of the optimized elements in the above combination is reduced, and the fatigue life of the cab assembly is calculated. Sensitivity analysis is carried out between the fatigue life of the cab assembly and the thickness of the optimized elements in each combination. The combination with high sensitivity is excluded from the optimization object range, and the thickness of the optimized elements in the remaining combination is used as the key design variable.

[0163] ④ At the same time, based on the finite element grid model of the cab assembly before optimization, the minimum thickness of the optimized elements in the remaining combination is obtained when meeting the fatigue life requirement through fatigue life simulation calculation, as the lower limit of the key design variable, and the original thickness of the element is used as the upper limit of the feasible region, and the feasible region Ω of the key design variable is determined, i.e. the changeable range of the thickness of each element.

[0164] 10) Interpolation in feasible region and scheme optimization calculation

[0165] ① The calculated total mass of the cab assembly should be less than the target cab assembly total mass as the judgment basis, and the number of each combination and the thickness of the optimized elements in each combination are used as the two-dimensional coordinates of the feasible region. The total mass of the cab assembly corresponding to each combination under different thickness is calculated, and the combinations and the thickness corresponding to the combinations that do not meet the judgment basis are excluded.

[0166] ② The number of each combination and the thickness of the optimized elements in each combination are used as the two-dimensional coordinates of the feasible region, and a predetermined interpolation method is used for interpolation in the feasible region to obtain several schemes, and the expression of each scheme is: (combination number, thickness of optimized elements in combination).

[0167] Fatigue life simulation calculation is carried out for each optimization scheme, and based on the fatigue life simulation calculation results, the combination that meets the fatigue life requirement and the thickness corresponding to each combination are selected.

[0168] Based on the screened combinations and the corresponding plate thickness of each combination, the optimized total mass of the cab assembly is calculated, and the smallest total mass of the cab assembly is selected, and the calculation formula is as follows:

[0169] minf(x)=min{f Ⅰ (x),f Ⅱ (x),f Ⅲ (x),f Ⅳ (x),f Ⅴ (x),…,f k (x)}+f C

[0170] x=[x I ,x II ,x III ,x IV ,x V ,…x k ] T

[0171] Wherein, x is a key design variable, x=[x I ,x II ,x III ,x IV ,x V ,…x k ] T is the variable space; I, II, III, IV, V… is the number of the screened combinations; f(x) is the optimized total mass of the cab assembly; f k (x) is the mass of each screened combination; f C is the remaining value of the total mass of the cab assembly minus the original mass of all screened elements to be optimized.

[0172] If the difference between the optimized smallest total mass of the cab assembly and the target total mass of the cab assembly is less than the preset value, the plate thickness corresponding to the screened combination is taken as the optimal combination.

[0173] If the standard is met, the next process is entered.

[0174] If the standard is not met, the screened combination and the plate thickness corresponding to the combination are found, and the optimization range is set in the adjacent area, the 2nd-3rd round interpolation and calculation are performed, and the optimal scheme of fatigue life and lightweight synergism is found.

[0175] If the optimal scheme meets the standard, the next process is entered.

[0176] If it does not meet the standard, return to step 8) and reset the optimization target, determine the key design variable and its feasible region, and perform interpolation and scheme optimization calculation in the feasible region.

[0177] Step 4: Check the basic performance of the improved cab assembly

[0178] 11) Analyze the basic performance of the improved cab assembly (including structural static strength simulation, etc.)

[0179] The key basic performance of the improved cab assembly is simulated and analyzed, including structural static strength, etc. The analysis results are compared with the basic performance of the cab assembly before improvement. After meeting the requirements of various basic performances, the next step can be entered.

[0180] Otherwise, return to step 8) to reset the optimization target, determine the key design variables and their feasible region, and perform interpolation and scheme optimization calculation.

[0181] Step 5: Submit the fatigue life and lightweight collaborative optimization scheme of the cab assembly

[0182] 12) Submit the collaborative optimization scheme, which includes the names of all elements to be optimized, the thickness of the plates, and the names and parameters of other elements. Provide a completed collaborative optimization simulation analysis report.

[0183] The basic principles and main features of the present application and the advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A vibration damping device for a cab, characterized by: The first damping unit comprises a protective net, a fixed plate, a base, a guide element, a first elastic element and a limiting element; The fixed plate is arranged opposite to the base and connected with the protective net; The guide element is located between the fixed plate and the base and arranged opposite to the base, forming a movement space between the guide element and the base, and the base is used for being connected with the cab body; The first elastic element is arranged in the movement space; One end of the limiting element is connected with the base, and the other end cooperates with the fixed plate to limit the stroke of the first elastic element; The limiting element comprises a limiting cylinder and a limiting plate, and the guide element comprises a guide rod and a guide plate; One end of the limiting cylinder is connected with the base, and the other end cooperates with the fixed plate to limit the stroke of the first elastic element; The limiting plate is an elastic body, connected with the fixed plate, and can reciprocate in the limiting cylinder; The guide plate is arranged opposite to the base, forming a movement space therebetween; One end of the guide rod is connected with the base, and the other end penetrates the guide plate, the limiting plate and the fixed plate in sequence, and the guide plate, the limiting plate and the fixed plate can reciprocate along the guide rod; The first elastic element is a rubber spring body; The rubber spring body comprises an inner metal ring body, a rubber outer ring body and a boss rubber structure; The inner metal ring body is hollow; The rubber outer ring body is arranged outside the inner metal ring body and connected with the inner metal ring body through the boss rubber structure; At one end of the rubber spring body, the end of the rubber outer ring body is higher than the end of the inner metal ring body and the boss rubber structure, and the end of the inner metal ring body is higher than the end of the boss rubber structure; at the other end of the rubber spring body, the end of the inner metal ring body is higher than the end of the rubber outer ring body and the boss rubber structure; The outer diameter of the inner metal ring body is 1 / 3-2 / 3 of the diameter of the rubber spring body, the thickness of the rubber outer ring body is 1 / 10-1 / 3 of the diameter of the rubber spring body, and the diameter of the boss rubber structure is greater than or equal to 1 / 10 of the diameter of the rubber spring body.

2. The vibration damping device for a cab according to claim 1, characterized by: The first damping unit further comprises a damping element, which is a damping rod or a particle damping material; the particle damping material is arranged in a closed space formed between the rubber spring body and the guide plate.

3. The vibration damping device for a cab according to claim 1, characterized by: The frequency modulation ratio of the first damping unit is 0.85-0.

95.

4. The vibration damping device for a cab according to claim 1, characterized by: The damping device further comprises a second damping unit; the second damping unit comprises a fixed frame, a combined mass block and a second elastic element; the combined mass block is installed in the fixed frame and comprises a mass block fixing frame and a plurality of sub-mass blocks connected with the mass block fixing frame, and the number and shape of the sub-mass blocks are determined by the vibration frequency to be eliminated; The second elastic element is arranged between the fixed frame and the combined mass block, has stiffness and damping characteristics, and has two directions of freedom.

5. A vibration damping device for a cab according to claim 4, characterized in that: The frequency modulation ratio of the second elastic element is 0.90-0.

97.

6. A cab characterized in that The damping device comprises the damping device of any one of claims 1-5.

7. A method for synergistic optimization of fatigue life and lightweight design for driver's cabs, characterized in that, The method comprises the following steps of: taking the thickness of the elements in the cab body that meet preset conditions as key design variables; taking the original thickness of each element that meets the preset conditions before optimization and the minimum thickness of the element that meets the fatigue life index as a feasible region; performing interpolation in the feasible region to obtain an optimal combination of the key design variables, taking the fatigue life of the cab assembly and the total weight of the cab assembly as collaborative optimization objectives, and taking the performance of the cab assembly after optimization being superior to or equal to the performance of the cab assembly before optimization as a constraint condition, wherein the cab assembly comprises the cab body and the damping device according to any one of claims 1-5.

8. The fatigue life and lightweight co-optimization method for a cab according to claim 7, characterized in that: The step of taking the elements in the cab body that meet preset conditions as key design variables comprises the following steps of: obtaining preset elements to be optimized; selecting elements to be optimized whose weight-to-total mass ratio of the cab assembly is greater than a set threshold value, and grouping elements to be optimized whose thickness difference is less than a set threshold value to form a plurality of combinations; based on the finite element grid model of the cab assembly before optimization, calculating the fatigue life of each combination corresponding to different thicknesses of the elements to be optimized in a combination by reducing the thickness of the elements to be optimized, and further calculating the sensitivity between each combination and the fatigue life of the cab assembly; deleting combinations with a sensitivity greater than a set threshold value, and taking the thickness of the elements to be optimized in the remaining combinations as key design variables.

9. The fatigue life and lightweight co-optimization method for a cab according to claim 7, wherein: The minimum thickness of the element to be optimized that meets the fatigue life index is obtained by the following steps of: based on the finite element grid model of the cab assembly before optimization, obtaining the minimum thickness of the element to be optimized in the remaining combinations that meets the fatigue life requirement through fatigue life simulation calculation.

10. The fatigue life and lightweight co-optimization method for a cab according to claim 7, wherein: The step of performing interpolation in the feasible region to obtain an optimal combination of the key design variables, taking the fatigue life of the cab assembly and the total weight of the cab assembly as collaborative optimization objectives, and taking the performance of the cab assembly after optimization being superior to or equal to the performance of the cab assembly before optimization as a constraint condition comprises the following steps of: taking the number of each combination and the thickness of the elements to be optimized in each combination as two-dimensional coordinates of the feasible region, and performing interpolation in the feasible region by using a preset interpolation method to obtain a plurality of schemes, wherein the expression of each scheme is (the number of the combination, the thickness of the elements to be optimized in the combination); performing fatigue life simulation calculation for each optimization scheme, and selecting combinations that meet the fatigue life requirement and the thickness of the elements to be optimized corresponding to each combination based on the fatigue life simulation calculation results; calculating the total mass of the cab assembly after optimization based on the selected combinations and the thickness of the elements to be optimized corresponding to each combination, and selecting the smallest total mass of the cab assembly after optimization; if the difference between the smallest total mass of the cab assembly after optimization and the target total mass of the cab assembly is less than a preset value, taking the thickness of the elements to be optimized corresponding to the selected combinations as the optimal combination.

11. The fatigue life and lightweight co-optimization method for a cab according to claim 10, wherein: The smallest total mass of the cab assembly is obtained by the following formula: min f(x) = min{f Ⅰ (x), f Ⅱ (x), f Ⅲ (x), f Ⅳ (x), f Ⅴ (x), …, f k (x)} + f C x = [x I ,x II ,x III ,x IV ,x V ,…x k ] T Wherein, x is the key design variable, x = [x I ,x II ,x III ,x IV ,x V ,…x k ] T is the variable space; I, II, III, IV, V… is the number of the screened combination; f(x) is the total mass of the cab assembly after optimization; f k (x) is the mass of each screened combination; f C is the remaining value of the total mass of the cab assembly minus the original mass of all screened elements to be optimized.

12. The method for fatigue life and lightweighting co-optimization of a cab according to claim 10, wherein: Before the step of taking the number of each combination and the thickness of the elements to be optimized in each combination as two-dimensional coordinates of the feasible region, the method further comprises the following steps of: calculating the total mass of the cab assembly corresponding to each combination under different thicknesses of the elements to be optimized, taking the number of each combination and the thickness of the elements to be optimized in each combination as two-dimensional coordinates of the feasible region. The calculated cab assembly total mass should be less than the target cab assembly total mass as the judgment basis, excluding the combination that does not meet the judgment basis, and the corresponding plate thickness of the combination.

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