A ROPS skeleton design method and a construction machinery cab

Abstract

The present invention discloses a ROPS skeleton design method and a construction machinery cab. The ROPS skeleton design method includes: calculating the lateral loading force F of the ROPS skeleton according to earthmoving machinery standards max and the lateral load energy U max target values; selecting a suitable cab skeleton structure type from the simple supported beam structural mechanics model; according to the created maximum lateral loading force F max quick calculation formula and the maximum load energy U max quick calculation formula, calculating the sum of the section moduli of the profiles of all columns and top crossbeams, and accordingly selecting suitable profiles, and using the selected cab skeleton structure type to build a closed space frame structure.

Description

Technical Field

[0001] The present invention belongs to the technical field of construction machinery cabs, and relates to a ROPS frame design method and a construction machinery cab. Background Art

[0002] Engineering vehicles work in harsh environments, and the driving roads are complex and changeable, so rollover accidents often occur. Engineering vehicles are relatively heavy, and the fatality rate of rollover accidents is extremely high. The fundamental reason for fatal injuries is the extreme deformation of the cab after an accident. Rollover accidents are inevitable. In order to reduce the loss of life and property caused by accidents, the most effective and simple method is to take passive protection, that is, to install a rollover protection structure (ROPS) that can provide certain safety protection on the vehicle.

[0003] Currently, the ROPS frame design of construction machinery cabs widely adopts the method of three-dimensional digital simulation analysis plus prototype vehicle verification. There are problems such as designers being unable to reasonably plan the ROPS frame structure form and profile selection at the initial stage of the project, repeatedly modifying the three-dimensional digital model, and a long simulation cycle.

[0004] Currently, the method of three-dimensional digital simulation analysis is widely used in the industry. After the designer completes the design of the three-dimensional digital model of the cab frame, the simulation analyst completes the simulation analysis on computer-aided analysis software such as HYPERMESH and ANSYS according to the ROPS loading requirements. Then, the designer modifies the three-dimensional digital model according to the simulation results (insufficient or excessive ROPS bearing capacity). Such a communication process usually has 2-3 cycles, and each cycle takes 1-2 weeks, making it impossible to achieve high-efficiency design work.

[0005] The existing technology has the following defects: (1) The development cycle of the cab ROPS frame is long; (2) It can only be implemented after the designer completes the three-dimensional digital model, and it cannot support the work of selecting the cab frame structure form and profile at the initial stage of design; (3) It occupies simulation analysis resources for a long time and has a high design cost. Summary of the Invention

[0006] Objective: In order to overcome the deficiencies in the existing technology, the present invention provides a ROPS frame design method and a construction machinery cab.

[0007] Technical Solution: To solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0008] In the first aspect, a ROPS frame design method is provided, including:

[0009] According to the maximum overall machine mass of the applicable model of the ROPS frame, calculate the lateral loading force F of the ROPS frame according to the regulations in GB / T 17922, GB / T 19930 or GB / T19930.2max and the lateral load energy U max Target value;

[0010] According to the characteristics of the applicable cab models, select the appropriate cab skeleton structure type from the simple supported beam structural mechanics model; wherein the simple supported beam structural mechanics model includes a common cab skeleton structure, a middle crossbeam reinforced skeleton structure, and a diagonal beam reinforced skeleton structure;

[0011] Based on the skeleton structure type of the simple supported beam structural mechanics model and the calculated lateral loading force F of the ROPS skeleton max and the lateral load energy U max Target value, according to the maximum lateral loading force F max Quick calculation formula, maximum load energy U max Quick calculation formula, calculate the sum value of the section moduli of two groups of profiles respectively, and select the larger value of the sum values of the section moduli of the two groups of profiles as the sum of the section moduli of all columns and top crossbeams that finally satisfy the relationship;

[0012] Select appropriate profiles according to the sum of the section moduli of the profiles, and use the selected cab skeleton structure type to build a closed space frame structure.

[0013] In some embodiments, the maximum load energy U max The quick calculation formula is:

[0014] U max = 1.5·S max ·K·σ 拉 ·∑{(W A_立柱 +W 顶_A横梁 ) / L A ,(W B_立柱 +W 顶_B横梁 ) / L B ,n·(W D_立柱 +W 顶_D横梁 ) / L D}= 0.42·K·σ 拉 ·∑{(W A_立柱 +W 顶_A横梁 ) / L A ,(W B_立柱 +W 顶_B横梁 ) / L B ,n·(W D_立柱 +W 顶_D横梁 ) / L D}

[0015] The maximum lateral loading force F max The quick calculation formula is:

[0016] F max = 2·K·σ 拉·∑{(∑{(W A_立柱 +W 顶_A横梁 ) / L A ,(W B_立柱 +W 顶_B横梁 ) / L B ,n·(W D_立柱 +W 顶_D横梁 ) / L D}

[0017] where n is the structural strengthening coefficient, which is determined according to the selected cab skeleton structure type;

[0018] F max and U max adopt the calculated lateral loading force F max and the lateral load energy U max target values;

[0019] K represents the strengthening coefficient of the fully plastic deformation zone, which is obtained by regression analysis based on the maximum lateral loading force F max in the experimental data;

[0020] The maximum deformation displacement S max adopts the median value of the normal statistical data in the experimental data;

[0021] σ 拉 represents the tensile stress limit value of the material, which is a fixed value according to the selected material;

[0022] L A 、L B 、L D 、L d are known values according to the selected cab skeleton structure type, and respectively represent the height dimension of the A-pillar, the height dimension of the B-pillar, the height dimension of the D-pillar, and the height dimension from the highest point of the D-pillar of the diagonal beam strengthening skeleton structure to the highest point of the diagonal beam.

[0023] In some embodiments, where n is the structural strengthening coefficient, which is determined according to the selected cab skeleton structure type, including:

[0024] Ordinary cab skeleton structure: n is 1;

[0025] Middle crossbeam strengthening skeleton structure: n = (W 立柱 +W 顶_横梁 +W 中_横梁 ) / (W D_立柱 +W 顶_D横梁 );

[0026] Diagonal beam strengthening skeleton structure: n = L D / L d .

[0027] In some embodiments, the maximum lateral loading force F max Quick calculation formula and the maximum lateral loading force F max The method for creating the quick calculation formula includes:

[0028] S1. Create a mechanical model: Based on the lateral push loading force F and the lateral push load energy U required in the ROPS test as the design objectives, establish the relationship between the lateral push loading force F, the lateral push load energy U, and the geometric parameters of the profile for bending resistance, obtain the mechanical model of the simply supported beam structure, and analyze the bending moment balance formula from the simply supported beam structure mechanical model: the sum of the resisting bending moments of each plastic hinge is equal to the bending moment generated by the loading force;

[0029] S2. Select design parameters: Analyze the bending moment balance formula to obtain the section modulus W of the geometric parameters of the profile for bending resistance. The section modulus W is the key factor determining the maximum bearing capacity M max of the ROPS frame profile. The relationship between the section modulus W and the maximum bearing capacity M max is: M max =K·σ 拉 ·W;

[0030] Substitute M max =K·σ 拉 ·W into the bending moment balance formula obtained in S1 to obtain the formula for the maximum lateral loading force of the ROPS frame;

[0031] S3. Obtain the experimental data of the frame profile of the ROPS entering the fully plastic deformation zone in the lateral push test, and extract the maximum lateral loading force F max , the maximum lateral load energy U max and the maximum deformation displacement S max ; According to the maximum deformation displacement S max in the experimental data, take the median of the normal statistical data;

[0032] S4. According to the maximum lateral loading force F max extracted from the experimental data, perform regression analysis to obtain the K value in the relationship created in S2, and obtain the quick calculation formula for the maximum lateral loading force F max of the ROPS frame, expressed as:

[0033] F max =2·K·σ 拉 ·∑{(W A_立柱 +W 顶_A横梁 ) / L A ,(W B_立柱 +W 顶_B横梁 ) / L B ,n·(W D_立柱 +W 顶_D横梁 ) / L D}

[0034] where n is the structural strengthening coefficient;

[0035] Ordinary cab skeleton structure: n is 1;

[0036] Middle crossbeam strengthening skeleton structure: n = (W 立柱 + W 顶_横梁 + W 中_横梁 ) / (W D_立柱 + W 顶_D横梁 );

[0037] Diagonal tension beam strengthening skeleton structure: n = L D / L d ;

[0038] By statistically analyzing the relationship curve between the lateral loading force F and the lateral deformation displacement S in the database created by S3, it is obtained that the load energy absorbed in the plastic deformation zone accounts for 2 / 3 of the total load energy, the displacement in the plastic deformation zone accounts for 1 / 2 of the total deformation displacement, and the maximum deformation displacement S max The median value of the normal statistical data is 0.28 m, from which the maximum load energy U max Quick calculation formula, expressed as:

[0039] U max = 0.75 · F max · S max = 1.5 · S max · K · σ 拉 · ∑{(W A_立柱 + W 顶_A横梁 ) / L A , (W B_立柱 + W 顶_B横梁 ) / L B , n · (W D_立柱 + W 顶_D横梁 ) / L D}

[0040] = 0.42 · K · σ 拉 · ∑{(W A_立柱 + W 顶_A横梁 ) / L A , (W B_立柱 + W 顶_B横梁 ) / L B , n · (W D_立柱 + W 顶_D横梁 ) / L D};

[0041] In some embodiments, S1 includes: The simply supported beam structure mechanical model includes three types: ordinary cab skeleton structure, middle crossbeam strengthening skeleton structure, and diagonal tension beam strengthening skeleton structure;

[0042] The bending moment equilibrium formula of the simply supported beam structure mechanical model of the ordinary cab skeleton structure is:

[0043] 2·(M 立柱 +M 顶_横梁 ) = F·L,

[0044] The bending moment equilibrium formula of the simply supported beam structure mechanical model of the middle crossbeam reinforced skeleton structure is:

[0045] 2·(M 立柱 +M 顶_横梁 +M 中_横梁 ) = F·L

[0046] The bending moment equilibrium formula of the simply supported beam structure mechanical model of the diagonal tension beam reinforced skeleton structure is:

[0047] 2·(M 立柱 +M 顶_横梁 ) = F·L d

[0048] Where M 立柱 , M 顶_横梁 , M 中_横梁 are the plastic hinge resisting moments of the columns, the top crossbeam, and the middle crossbeam respectively, F is the lateral loading force of the simply supported beam structure, and L is the height dimension of the columns;

[0049] S2 includes: the maximum lateral loading force formula of the ROPS skeleton;

[0050] a) The maximum lateral loading force formula of the ordinary cab skeleton structure:

[0051] F max =2·K·σ 拉 ·(W 立柱 +W 顶_横梁 ) / L

[0052] b) The maximum lateral loading force formula of the middle crossbeam reinforced skeleton structure:

[0053] F max =2·K·σ 拉 ·(W 立柱 +W 顶_横梁 +W 中_横梁 ) / L

[0054] c) The maximum lateral loading force formula of the diagonal tension beam reinforced skeleton structure:

[0055] F max =2·K·σ 拉 ·(W 立柱 +W 顶_横梁 ) / L d .

[0056] In some embodiments, the maximum deformation displacement S in S3 max The median value of the normal statistical data is 0.28 m.

[0057] Second, three types of ROPS skeleton types of the simple supported beam structural mechanics model are provided:

[0058] The first type: A common cab ROPS skeleton with central symmetry, including columns, cross beams, and longitudinal beams;

[0059] Wherein the columns include A-pillars, B-pillars, and D-pillars; the cross beams include a top cross beam and a bottom cross beam; the longitudinal beams include a top longitudinal beam and a bottom longitudinal beam;

[0060] Two A-pillars are connected by a first top cross beam and a first bottom cross beam to form a closed rectangular A-ring;

[0061] Two B-pillars are connected by a second top cross beam and a second bottom cross beam to form a closed rectangular B-ring;

[0062] Two D-pillars are connected by a third top cross beam and a third bottom cross beam to form a closed rectangular D-ring;

[0063] The four corner positions corresponding to the A-ring and the B-ring are connected by a first top longitudinal beam and a first bottom longitudinal beam, and the four corner positions corresponding to the B-ring and the D-ring are connected by a second top longitudinal beam and a second bottom longitudinal beam to form a closed space frame structure;

[0064] The ROPS skeleton is designed by using the design method of the ROPS skeleton.

[0065] The second type: A central symmetry middle cross beam strengthened ROPS skeleton, including columns, cross beams, longitudinal beams, and a middle cross beam;

[0066] Wherein the columns include A-pillars, B-pillars, and D-pillars; the cross beams include a top cross beam and a bottom cross beam; the longitudinal beams include a top longitudinal beam and a bottom longitudinal beam;

[0067] Two A-pillars are connected by a first top cross beam and a first bottom cross beam to form a closed rectangular A-ring;

[0068] Two B-pillars are connected by a second top cross beam and a second bottom cross beam to form a closed rectangular B-ring;

[0069] Two D-pillars are connected by a third top cross beam and a third bottom cross beam to form a closed rectangular D-ring; both ends of the middle cross beam are respectively connected to the inner sides of the middles of the two D-pillars, and the third top cross beam, the middle cross beam, and the third bottom cross beam are arranged in parallel;

[0070] The four corner positions corresponding to the A-ring and the B-ring are connected by a first top longitudinal beam and a first bottom longitudinal beam, and the four corner positions corresponding to the B-ring and the D-ring are connected by a second top longitudinal beam and a second bottom longitudinal beam to form a closed space frame structure;

[0071] The ROPS framework is designed by using the design method of the ROPS framework described above.

[0072] The third type: A symmetrically axially-pulled beam reinforced ROPS framework, comprising columns, cross beams, and longitudinal beams; further comprising two axially-pulled beams;

[0073] Wherein the columns include column A, column B, and column D; the cross beams include a top cross beam and a bottom cross beam; the longitudinal beams include a top longitudinal beam and a bottom longitudinal beam;

[0074] Two column As are connected by a first top cross beam and a first bottom cross beam to form a closed rectangular ring A;

[0075] Two column Bs are connected by a second top cross beam and a second bottom cross beam to form a closed rectangular ring B;

[0076] Two column Ds are connected by a third top cross beam and a third bottom cross beam to form a closed rectangular ring D;

[0077] One end of the axially-pulled beam is connected to the inner side of the middle of column D, and the other end is connected to the third bottom cross beam;

[0078] The corresponding four corners of ring A and ring B are connected by a first top longitudinal beam and a first bottom longitudinal beam, and the corresponding four corners of ring B and ring D are connected by a second top longitudinal beam and a second bottom longitudinal beam to form a closed space frame structure;

[0079] The ROPS framework is designed by using the design method of the ROPS framework described above.

[0080] In a third aspect, the present invention further provides a construction machinery cab, comprising the ROPS framework described above.

[0081] Beneficial effects: The ROPS framework, its design method, and the construction machinery provided by the present invention have the following advantages:

[0082] (1) Based on the established maximum lateral loading force F max quick calculation formula and the maximum load energy U max quick calculation formula, the present invention can realize the selection of profiles and the comparison of multiple schemes by manual calculation, and control the ROPS framework design time within 4 hours, greatly shortening the design cycle;

[0083] (2) Make full use of the limit value of the bearing capacity of the profiles, and create relationships and guide the profile selection based on the experimental data of this database, so as to realize the lightweight design of the ROPS framework and improve the design quality. Description of the Drawings

[0084] Figure 1 It is a flowchart of the ROPS framework design method in an embodiment of the present invention;

[0085] Figure 2This is the ROPS frame structure of the ordinary cab in the embodiment of the present invention;

[0086] Figure 3 This is the ROPS frame structure with reinforced middle beam in the embodiment of the present invention;

[0087] Figure 4 This is the ROPS frame structure with reinforced diagonal beam in the embodiment of the present invention;

[0088] Figure 5 This is the mechanical model of the ROPS frame of the ordinary cab in the embodiment of the present invention;

[0089] Figure 6 This is the mechanical model of the ROPS frame with reinforced middle beam in the embodiment of the present invention;

[0090] Figure 7 This is the mechanical model of the ROPS frame with reinforced diagonal beam in the embodiment of the present invention. Detailed implementation manners

[0091] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way restricts the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0092] Unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions, and numerical values described in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that for the sake of convenience of description, the dimensions of each part shown in the drawings are not drawn according to the actual proportional relationship. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the said technologies, methods, and devices should be regarded as part of the authorization specification. In all the examples shown and discussed here, any specific value should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0093] In the description of the present disclosure, it should be understood that the use of words such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Without further statement, the above words have no special meaning and therefore cannot be construed as limiting the scope of protection of the present disclosure.

[0094] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation on the protected content of the present invention.

[0095] ROPS - Rollover Protection Structure, a series of structural members that reduce the possibility of a seat - belted driver being crushed when the machine rolls over.

[0096] ROPS framework - A spatial frame structure formed to meet the ROPS design requirements;

[0097] Column - A component or member that provides vertical support;

[0098] Cross - beam - A beam - type structural member arranged horizontally;

[0099] Section modulus - Also known as section modulus, a geometric parameter that reflects the ability of a component cross - section to resist bending deformation;

[0100] Plastic hinge - When the ROPS framework is under bending moment, a point that appears locally on the component, where the opposite surfaces yield but do not fail, and the component can rotate around it by a limited angle. This point can be called a plastic hinge;

[0101] Plastic deformation zone - When loaded laterally, multiple plastic hinges appear in the ROPS framework, making the ROPS framework unable to maintain a statically determinate structure. This state is called the plastic deformation zone.

[0102] Embodiment 1

[0103] As Figure 2 shown, a ROPS framework for a centrally - symmetric ordinary cab includes columns, cross - beams, and longitudinal beams;

[0104] Among them, the columns include A - pillar 10, B - pillar 20, and D - pillar 30; the cross - beams include a top cross - beam and a bottom cross - beam; the longitudinal beams include a top longitudinal beam and a bottom longitudinal beam;

[0105] Two A - pillars 10 are connected by a first top cross - beam 11 and a first bottom cross - beam 12 to form a closed rectangular A - ring;

[0106] Two B - pillars 20 are connected by a second top cross - beam 21 and a second bottom cross - beam 22 to form a closed rectangular B - ring;

[0107] Two D - pillars 30 are connected by a third top cross - beam 31 and a third bottom cross - beam 32 to form a closed rectangular D - ring;

[0108] The four corner positions corresponding to the A-ring and the B-ring are connected by the first top longitudinal beam 41 and the first bottom longitudinal beam 42, and the four corner positions corresponding to the B-ring and the D-ring are connected by the second top longitudinal beam 51 and the second bottom longitudinal beam 52 to form a closed space frame structure.

[0109] Such as Figure 3 shown, a middle beam strengthened ROPS skeleton with central symmetry includes columns, cross beams, longitudinal beams, and a middle beam 60;

[0110] Wherein the columns include column A 10, column B 20, and column D 30; the cross beams include a top cross beam and a bottom cross beam; the longitudinal beams include a top longitudinal beam and a bottom longitudinal beam;

[0111] Two column A 10s are connected by the first top cross beam 11 and the first bottom cross beam 12 to form a closed rectangular A-ring;

[0112] Two column B 20s are connected by the second top cross beam 21 and the second bottom cross beam 22 to form a closed rectangular B-ring;

[0113] Two column D 30s are connected by the third top cross beam 31 and the third bottom cross beam 32 to form a closed rectangular D-ring;

[0114] Both ends of the middle beam 60 are respectively connected to the inner sides of the middle parts of the two column Ds, and the third top cross beam, the middle beam, and the third bottom cross beam are arranged in parallel;

[0115] The four corner positions corresponding to the A-ring and the B-ring are connected by the first top longitudinal beam 41 and the first bottom longitudinal beam 42, and the four corner positions corresponding to the B-ring and the D-ring are connected by the second top longitudinal beam 51 and the second bottom longitudinal beam 52 to form a closed space frame structure.

[0116] Such as Figure 4 shown, a stay cable strengthened ROPS skeleton with central symmetry includes columns, cross beams, longitudinal beams; and also includes two stay cables 70,

[0117] Wherein the columns include column A 10, column B 20, and column D 30; the cross beams include a top cross beam and a bottom cross beam; the longitudinal beams include a top longitudinal beam and a bottom longitudinal beam;

[0118] Two column A 10s are connected by the first top cross beam 11 and the first bottom cross beam 12 to form a closed rectangular A-ring;

[0119] Two column B 20s are connected by the second top cross beam 21 and the second bottom cross beam 22 to form a closed rectangular B-ring;

[0120] Two column D 30s are connected by the third top cross beam 31 and the third bottom cross beam 32 to form a closed rectangular D-ring;

[0121] One end of the inclined beam 70 is connected to the inner side of the middle part of the D-pillar 30, and the other end is connected to the third bottom cross beam 32;

[0122] The four corners corresponding to the A ring and the B ring are connected by the first top longitudinal beam 41 and the first bottom longitudinal beam 42, and the four corners corresponding to the B ring and the D ring are connected by the second top longitudinal beam 51 and the second bottom longitudinal beam 52, forming a closed space frame structure.

[0123] In the above three ROPS frames, the A ring, the B ring and the D ring are all rectangular structures, and the entire ROPS frame is symmetrical along the central axis.

[0124] Among them, the longitudinal beams include top longitudinal beams and bottom longitudinal beams; in order to ensure the flatness of the bottom of the entire ROPS frame, the bottom longitudinal beam is basically set in the same plane as the bottom cross beam (for example, horizontally set), but the lengths of the A-pillar, B-pillar, and D-pillar are not necessarily equal, so the top longitudinal beam and the top cross beam are not necessarily located in the same plane.

[0125] Figure 5 , Figure 6 and Figure 7 The simply supported beam structure mechanical models shown are respectively the simply supported beam structure mechanical models of the above-mentioned ordinary cab frame structure, the middle cross beam reinforced frame structure, and the cable-stayed beam reinforced frame structure.

[0126] In some embodiments, the sum of the profile section moduli of all columns and top crossbeams in the above three ROPS frames meets the design method requirements described in Example 2.

[0127] Example 2

[0128] like Figure 1 As shown, a design method of a ROPS frame includes:

[0129] S1. Create a mechanical model: Based on the side thrust load force F and side thrust load energy U required in the ROPS test as design targets, create a relationship between the side thrust load force F and side thrust load energy U and the anti-bending geometric parameters of the profile, and obtain a simply supported beam structural mechanical model. According to the simply supported beam structural mechanical model, the moment equilibrium formula is obtained: the sum of the resisting moments of each plastic hinge is equal to the bending moment generated by the loading force;

[0130] The simply supported beam structural mechanical model includes three types: a common cab skeleton structure, a middle cross beam reinforced skeleton structure, and a cable-stayed beam reinforced skeleton structure;

[0131] Figure 5 The moment balance formula of the simply supported beam structural mechanics model of the ordinary cab skeleton structure shown is:

[0132] 2.(M 立柱 +M 顶_横梁 )=F·L

[0133] Figure 6 The bending moment equilibrium formula of the simply supported beam structure mechanical model of the middle crossbeam reinforcement skeleton structure shown is:

[0134] 2·(M 立柱 +M 顶_横梁 +M 中_横梁 ) = F·L

[0135] Figure 7 The bending moment equilibrium formula of the simply supported beam structure mechanical model of the stay cable beam reinforcement skeleton structure shown is:

[0136] 2·(M 立柱 +M 顶_横梁 ) = F·L d

[0137] Where M 立柱 , M 顶_横梁 , M 中_横梁 are the plastic hinge resisting moments of the columns, the top crossbeam, and the middle crossbeam respectively, F is the lateral loading force of the simply supported beam structure, and L is the height dimension of the column; L d is the height dimension from the highest point of the D column of the stay cable beam reinforcement skeleton structure to the highest point of the stay cable beam;

[0138] S2 Select design parameters: Analyze the bending moment equilibrium formula to obtain the section modulus W of the profile bending resistance geometric parameter. The section modulus W is the key factor determining the maximum bearing capacity M max of the ROPS skeleton profile. The relationship between the section modulus W and the maximum bearing capacity M max is: M max =K·σ 拉 ·W;

[0139] Substitute M max =K·σ 拉 ·W into the bending moment equilibrium formula obtained in S1 to get the formula for the maximum lateral loading force of the ROPS skeleton;

[0140] Figure 5 The formula for the maximum lateral loading force of the ordinary cab skeleton structure shown:

[0141] F max =2·K·σ 拉 ·(W 立柱 +W 顶_横梁 ) / L

[0142] Figure 6 The formula for the maximum lateral loading force of the middle crossbeam reinforcement skeleton structure shown:

[0143] F max =2·K·σ 拉 ·(W 立柱 +W 顶_横梁+W 中_横梁 ) / L

[0144] Figure 7 Formula for the maximum lateral loading force of the cable-stayed beam reinforcement skeleton structure shown:

[0145] F max = 2·K·σ 拉 ·(W 立柱 +W 顶_横梁 ) / L d

[0146] S3 ROPS test database, obtain the experimental data of the skeleton profiles entering the fully plastic deformation zone in the ROPS side thrust test, and extract the maximum lateral loading force F max , the maximum lateral load energy U max and the maximum deformation displacement S max , where the maximum deformation displacement S max The median of the normal statistical data is 0.28 m, and create a database;

[0147] S4 Create a relationship, and according to the maximum lateral loading force F obtained by extracting the experimental data max Regression analysis to obtain the K value in the relationship created by S2, and obtain the maximum lateral loading force F of the ROPS skeleton max Quick calculation formula, expressed as:

[0148] F max = 2·K·σ 拉 ·∑{(W A_立柱 +W 顶_A横梁 ) / L A ,(W B_立柱 +W 顶_B横梁 ) / L B ,n·(W D_立柱 +W 顶_D横梁 ) / L D}

[0149] where n is the structural strengthening coefficient;

[0150] Figure 5 Ordinary cab skeleton structure shown: n is 1;

[0151] Figure 6 Intermediate beam reinforcement skeleton structure shown: n = (W 立柱 +W 顶_横梁 +W 中_横梁 ) / (W D_立柱 +W 顶_D横梁 );

[0152] Figure 7 Cable-stayed beam reinforcement skeleton structure shown: n = L D / Ld ;

[0153] By statistically analyzing the relationship curve between the lateral loading force F and the lateral deformation displacement S in the database created by S3, it is obtained that the load energy absorbed in the plastic deformation zone accounts for 2 / 3 of the total load energy, and the displacement in the plastic deformation zone accounts for 1 / 2 of the total deformation displacement, that is: 2 / 3·U max =1 / 2·F max ·S max , the maximum deformation displacement S max The median of the normal statistical data is 0.28 m, and thus the maximum load energy U max The quick calculation formula is expressed as:

[0154] U max =0.75·F max ·S max =1.5·S max ·K·σ 拉 ·∑{(W A_立柱 +W 顶_A横梁 ) / L A ,(W B_立柱 +W 顶_B横梁 ) / L B ,n·(W D_立柱 +W 顶_D横梁 ) / L D}

[0155] =0.42·K·σ 拉 ·∑{(W A_立柱 +W 顶_A横梁 ) / L A ,(W B_立柱 +W 顶_B横梁 ) / L B ,n·(W D_立柱 +W 顶_D横梁 ) / L D}

[0156] where n is the structural strengthening coefficient, which is determined according to the selected cab skeleton structure type;

[0157] F max 、U max Adopt the calculated lateral loading force F max and the target value of the lateral load energy U max ;

[0158] K represents the strengthening coefficient of the fully plastic deformation zone, which is obtained by regression analysis based on the maximum lateral loading force F max in the experimental data;

[0159] The maximum deformation displacement S max Adopt the median of the normal statistical data in the experimental data;

[0160] σ 拉 represents the tensile stress limit value of the material, which is a fixed value according to the selected material;

[0161] L A 、L B 、L D 、L d are known values according to the selected cab skeleton structure type, and respectively represent the height dimension of the A-pillar, the height dimension of the B-pillar, the height dimension of the D-pillar, and the height dimension from the highest point of the D-pillar of the diagonal bracing beam reinforcement skeleton structure to the highest point of the diagonal bracing beam.

[0162] S5 Plan the applicable model range of the ROPS skeleton, reasonably divide the load-bearing capacity ladder of the series cab ROPS skeleton according to the principles of lightweight and generalization, and plan the applicable model range of the ROPS skeleton;

[0163] S6 Calculate the load-bearing requirements, based on the maximum overall machine mass of the applicable model of the ROPS skeleton, and determine the lateral loading force F of the ROPS skeleton according to the formulas specified in GB / T 17922, GB / T 19930 or GB / T 19930.2 max and the lateral load energy U max target values;

[0164] Table 1 of GB / T 17922

[0165]

[0166] Table 1 (continued) of GB / T 17922

[0167]

[0168] Table 1 of GB / T 19930

[0169]

[0170] Table 2 of GB / T 19930.2

[0171]

[0172] S7 Select the skeleton structure, and select a suitable cab skeleton structure type from the simple supported beam structural mechanics model according to the characteristics of the applicable model of the cab;

[0173] S8 Calculate the section parameters of the profile, according to the relationship created in S4, the lateral loading force F calculated in S6 max and the lateral load energy U max target values and the section modulus sum ∑(W 立柱 ,W 顶_横梁 ,W中_横梁 );

[0174] Based on the lateral loading force F of the ROPS skeleton obtained from the mechanical model skeleton structure type of the simply supported beam structure max and the lateral load energy U max target value, according to the maximum lateral loading force F max quick calculation formula, maximum load energy U max quick calculation formula, calculate the sum values of the section moduli of two groups of profiles respectively, and select the larger value of the sum values of the section moduli of the two groups as the final sum of the section moduli of the profiles ∑(W 立柱 , W 顶_横梁 ) or ∑(W 立柱 , W 顶_横梁 , W 中_横梁 );

[0175] U max = 0.42·K·σ 拉 ·∑{(W A_立柱 + W 顶_A横梁 ) / L A , (W B_立柱 + W 顶_B横梁 ) / L B , n·(W D_立柱 + W 顶_D横梁 ) / L D}

[0176] F max = 2·K·σ 拉 ·∑{(∑{(W A_立柱 + W 顶_A横梁 ) / L A , (W B_立柱 + W 顶_B横梁 ) / L B , n·(W D_立柱 + W 顶_D横梁 ) / L D}

[0177] where n is the structural strengthening coefficient, according to the selected cab skeleton structure type:

[0178] Ordinary cab skeleton structure: n is 1;

[0179] Middle crossbeam strengthened skeleton structure: n = (W 立柱 + W 顶_横梁 + W 中_横梁 ) / (W D_立柱 + W 顶_D横梁 );

[0180] Diagonal beam strengthened skeleton structure: n = L D / L d ;

[0181] F max and U max Adopt the calculated lateral loading force F max and the lateral load energy U max as the target values;

[0182] K represents the strengthening coefficient of the fully plastic deformation zone, which is obtained through regression analysis based on the maximum lateral loading force F in the experimental data max and is a fixed value;

[0183] σ 拉 represents the tensile stress limit value of the material, which is a fixed value according to the selected material;

[0184] L A and L B and L D and L d are known values according to the selected cab skeleton structure type.

[0185] S9. Select appropriate profiles according to the sum of the section moduli of the profiles ∑(W 立柱 , W 顶_横梁 ) or ∑(W 立柱 , W 顶_横梁 , W 中_横梁 ) obtained in S8, and build a closed space frame structure using the skeleton structure form selected in S7.

[0186] The ROPS test data from the simulation analysis and experimental verification is fed back to the S3 database, and the relationship in S4 is corrected using a large amount of experimental data to achieve the lightweight and precise design of the ROPS skeleton.

[0187] The sum of the section moduli of the ROPS skeleton ∑(W max , W max , W 立柱 , W 顶_横梁 , W 中_横梁 ) can be calculated according to the lateral loading force F 立柱 and the lateral load energy U 顶_横梁 , and the maximum lateral loading force F 中_横梁 and the lateral load energy U max of the ROPS skeleton can also be calculated according to the sum of the section moduli of the ROPS skeleton ∑(W max ), to achieve the comparative analysis and verification of multiple schemes.

[0188] Based on the relationship created in S4, the selection of profiles and the comparison of multiple schemes can be achieved through manual calculation, and the ROPS skeleton design time can be controlled within 4 hours, greatly shortening the design cycle.

[0189] The database requires that the ROPS skeleton profiles enter the fully plastic deformation zone, make full use of the limit value of the bearing capacity of the profiles, and create the relationship formula of S4 and guide the profile selection from this database, so as to realize the lightweight design of the ROPS skeleton and improve the design quality.

[0190] Embodiment 3

[0191] A cab of a construction machinery includes the ROPS skeleton described in Embodiment 1 and is designed by the method for optimizing the design of the middle beam in the ROPS skeleton described in Embodiment 2.

[0192] The construction machinery can be a hydraulic excavator, a loader, a roller, a grader, etc., and has the advantages of the ROPS skeleton provided by the embodiments of the present disclosure.

[0193] The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A design method for a ROPS skeleton, characterized in that, it includes: According to the maximum overall machine mass of the applicable machine type of the ROPS frame, the lateral loading force F of the ROPS frame is calculated according to the provisions in GB / T 17922, GB / T 19930 or GB / T 19930.2 max and the lateral load energy U max Target value; According to the characteristics of the applicable machine type of the cab, select a suitable cab skeleton structure type from the simple supported beam structural mechanics models; wherein the simple supported beam structural mechanics models include a common cab skeleton structure, a middle crossbeam strengthened skeleton structure, and a diagonal beam strengthened skeleton structure; Based on the skeletal structure type of the simply supported beam structural mechanics model and the lateral loading force F of the ROPS skeleton obtained by calculation max and the lateral load energy U max Target value. According to the maximum lateral loading force F max Quick calculation formula, maximum load energy U max Quick calculation formula, calculate the sum values of the section moduli of two groups of profiles respectively, and select the larger value of the sum values of the section moduli of the two groups of profiles as the sum of the section moduli of all columns and top crossbeams that finally satisfy the relationship Select suitable profiles according to the sum of the section moduli of the profiles, and use the selected cab skeleton structure type to build a closed space frame structure; The maximum lateral loading force F max The quick calculation formula is: F max = 2·K·σ 拉 ·∑{(∑{(W A_立柱 +W 顶_A横梁 ) / L A ,(W B_立柱 +W 顶_B横梁 ) / L B ,n·(W D_立柱 +W 顶_D横梁 ) / L D} The maximum load energy U max The quick calculation formula is: U max = 1.5·S max ·K·σ 拉 ·∑{(W A_立柱 + W 顶_A横梁 ) / L A , (W B_立柱 + W 顶_B横梁 ) / L B , n·(W D_立柱 + W 顶_D横梁 ) / L D} = 0.42·K·σ 拉 ·∑{(W A_立柱 + W 顶_A横梁 ) / L A , (W B_立柱 + W 顶_B横梁 ) / L B , n·(W D_立柱 + W 顶_D横梁 ) / L D} where n is the structural strengthening coefficient, which is determined according to the selected cab skeleton structure type; F max , U max Adopt the calculated lateral loading force F max and the lateral load energy U max target value; K represents the strengthening coefficient of the fully plastic deformation zone, which is obtained through regression analysis based on the maximum lateral loading force F max in the experimental data; the maximum deformation displacement S max Adopt the median value of the normal statistical data in the experimental data; σ 拉 represents the tensile stress limit value of the material, which is a fixed value according to the selected material; L A , L B , L D Are known values according to the selected cab skeleton structure type, and respectively represent the height dimension of the A-pillar, the height dimension of the B-pillar, and the height dimension of the D-pillar.

2. The design method for a ROPS skeleton according to claim 1, characterized in that, where n is a structural strengthening coefficient, which is determined according to the selected cab skeleton structure type, and includes: Common cab skeleton structure: n is 1; Middle crossbeam strengthening framework structure: n = (W 立柱 + W 顶_横梁 + W 中_横梁 ) / (W D_立柱 + W 顶_D横梁 ); Stayed beam reinforcement framework structure: n = L D / L d , L d represents the height dimension from the highest point of the D column of the stayed beam reinforcement framework structure to the highest point of the stayed beam.

3. The design method for a ROPS skeleton according to claim 1, characterized in that, The maximum lateral loading force F max The quick calculation formula and the maximum lateral loading force F max The method for creating the quick calculation formula includes: S1 Create a mechanical model: Based on the lateral push loading force F and the lateral push load energy U required in the ROPS test as the design goals, create a relational formula between the lateral push loading force F and the lateral push load energy U and the bending geometric parameters of the profiles, obtain the simple supported beam structural mechanics model, and analyze the bending moment balance formula according to the simple supported beam structural mechanics model: the sum of the resisting bending moments of each plastic hinge is equal to the bending moment generated by the loading force; S2 Select design parameters: Analyze the bending moment balance formula to obtain the section modulus W of the profile's bending resistance geometry. The section modulus W is the key factor determining the maximum load-bearing capacity M of the ROPS skeleton profile. max The relationship between the section modulus W and the maximum load-bearing capacity M max is as follows: M max = K·σ 拉 ·W; Substitute M max = K·σ 拉 ·W into S1, and the maximum lateral loading force formula of the ROPS frame can be obtained from the bending moment balance formula S3. Obtain the experimental data of the frame profile entering the fully plastic deformation zone in the ROPS side thrust test, and extract the maximum lateral loading force F max from the experimental data, the maximum lateral load energy U max and the maximum deformation displacement S max ; According to the maximum deformation displacement S max in the experimental data, use the median of the normal statistical data; S4. The maximum lateral loading force F obtained by extracting from the experimental data max The value of K in the relational expression created in S2 is obtained through regression analysis to obtain the maximum lateral loading force F of the ROPS framework max Quick calculation formula, expressed as: F max = 2·K·σ 拉 ·∑{(W A_立柱 + W 顶_A横梁 ) / L A , (W B_立柱 + W 顶_B横梁 ) / L B , n·(W D_立柱 + W 顶_D横梁 ) / L D} where n is a structural strengthening coefficient; Common cab skeleton structure: n is 1; Middle crossbeam reinforcement skeleton structure: n = (W 立柱 + W 顶_横梁 + W 中_横梁 ) / (W D_立柱 + W 顶_D横梁 ); Stayed beam reinforcement framework structure: n = L D / L d , L d represents the height dimension from the highest point of the D column of the stayed beam reinforcement framework structure to the highest point of the stayed beam; The relationship curve of the lateral loading force F and the lateral deformation displacement S in the database created by statistical analysis S3 shows that the load energy absorbed in the plastic deformation zone accounts for 2 / 3 of the total load energy, the displacement in the plastic deformation zone accounts for 1 / 2 of the total deformation displacement, and the maximum deformation displacement is S max The median of the normal statistical data is 0.28 m, from which the maximum load energy U is obtained max Quick calculation formula, expressed as: U max = 0.75·F max ·S max = 1.5·S max ·K·σ 拉 ·∑{(W A_立柱 + W 顶_A横梁 ) / L A ,(W B_立柱 + W 顶_B横 梁 ) / L B ,n·(W D_立柱 +W 顶_D横梁 ) / L D} = 0.42·K·σ 拉 ·∑{(W A_立柱 + W 顶_A横梁 ) / L A , (W B_立柱 + W 顶_B横梁 ) / L B , n·(W D_立柱 + W 顶_D横梁 ) / L D}.

4. The design method for a ROPS skeleton according to claim 3, characterized in that, S1 includes: The simple supported beam structural mechanics models include three types: a common cab skeleton structure, a middle crossbeam strengthened skeleton structure, and a diagonal beam strengthened skeleton structure; The bending moment balance formula of the simple supported beam structural mechanics model of the common cab skeleton structure is: 2·(M 立柱 +M 顶_横梁 ) = F·L, The bending moment balance formula of the simple supported beam structural mechanics model of the middle crossbeam strengthened skeleton structure is: 2·(M 立柱 +M 顶_横梁 +M 中_横梁 ) = F·L The bending moment balance formula of the simple supported beam structural mechanics model of the diagonal beam strengthened skeleton structure is: 2·(M 立柱 +M 顶_横梁 ) = F·L d Among which, M 立柱 , M 顶_横梁 , M 中_横梁 are respectively the plastic hinge resisting moment of the column, the plastic hinge resisting moments of the top cross beam and the middle cross beam, F is the lateral loading force of the simply supported beam structure, and L is the height dimension of the column; S2 includes: The maximum lateral loading force formula of the ROPS skeleton; a) The maximum lateral loading force formula of the common cab skeleton structure: F max = 2·K·σ 拉 ·(W 立柱 + W 顶_横梁 ) / L b) The maximum lateral loading force formula of the middle crossbeam strengthened skeleton structure: F max = 2·K·σ 拉 ·(W 立柱 + W 顶_横梁 + W 中_横梁 ) / L c) The maximum lateral loading force formula of the diagonal beam strengthened skeleton structure: F max = 2·K·σ 拉 ·(W 立柱 + W 顶_横梁 ) / L d 。 5. The design method for a ROPS skeleton according to claim 3, characterized in that, The maximum deformation displacement S in S3 max The median of the normal statistical data is 0.28 m.

6. A centrally symmetric common cab ROPS skeleton, characterized in that, it includes columns, crossbeams, and longitudinal beams; wherein the columns include column A, column B, and column D; the crossbeams include a top crossbeam and a bottom crossbeam; the longitudinal beams include a top longitudinal beam and a bottom longitudinal beam; Two column As are connected by a first top crossbeam and a first bottom crossbeam to form a closed rectangular A ring; Two column Bs are connected by a second top crossbeam and a second bottom crossbeam to form a closed rectangular B ring; Two column Ds are connected by a third top crossbeam and a third bottom crossbeam to form a closed rectangular D ring; The corresponding four corners of the A ring and the B ring are connected by a first top longitudinal beam and a first bottom longitudinal beam, and the corresponding four corners of the B ring and the D ring are connected by a second top longitudinal beam and a second bottom longitudinal beam to form a closed space frame structure; The ROPS skeleton is designed by using the design method for a ROPS skeleton according to any one of claims 1 to 5.

7. A centrally symmetric middle crossbeam strengthened ROPS skeleton, characterized in that, it includes columns, crossbeams, longitudinal beams, and middle crossbeams; Wherein the upright columns include column A, column B, and column D; the cross beams include a top cross beam and a bottom cross beam; the longitudinal beams include a top longitudinal beam and a bottom longitudinal beam; Two column A's are connected by a first top cross beam and a first bottom cross beam to form a closed rectangular ring A; Two column B's are connected by a second top cross beam and a second bottom cross beam to form a closed rectangular ring B; Two column D's are connected by a third top cross beam and a third bottom cross beam to form a closed rectangular ring D; both ends of the middle cross beam are respectively connected to the inner sides of the middles of two column D's, and the third top cross beam, the middle cross beam, and the third bottom cross beam are arranged in parallel; The corresponding four corners of ring A and ring B are connected by a first top longitudinal beam and a first bottom longitudinal beam, and the corresponding four corners of ring B and ring D are connected by a second top longitudinal beam and a second bottom longitudinal beam to form a closed space frame structure; The ROPS framework is designed by using the design method of the ROPS framework according to any one of claims 1 to 5.

8. A ROPS framework with a symmetrically arranged diagonal tension beam for reinforcement, characterized in that, it includes upright columns, cross beams, longitudinal beams; and also includes two diagonal tension beams; Wherein the upright columns include column A, column B, and column D; the cross beams include a top cross beam and a bottom cross beam; the longitudinal beams include a top longitudinal beam and a bottom longitudinal beam; Two column A's are connected by a first top cross beam and a first bottom cross beam to form a closed rectangular ring A; Two column B's are connected by a second top cross beam and a second bottom cross beam to form a closed rectangular ring B; Two column D's are connected by a third top cross beam and a third bottom cross beam to form a closed rectangular ring D; One end of the diagonal tension beam is connected to the inner side of the middle of column D, and the other end is connected to the third bottom cross beam; The corresponding four corners of ring A and ring B are connected by a first top longitudinal beam and a first bottom longitudinal beam, and the corresponding four corners of ring B and ring D are connected by a second top longitudinal beam and a second bottom longitudinal beam to form a closed space frame structure; The ROPS framework is designed by using the design method of the ROPS framework according to any one of claims 1 to 5.

9. An engineering machinery cab, characterized in that, it includes the ROPS framework according to any one of claims 6 - 8.

Images