A design method for selecting the number and length of telescopic aerial work vehicle arms

Abstract

A design method for selecting the number of sections and length of a telescopic aerial work platform arm, which can maximize the use of the mechanical properties of materials, is fast and effective, and can model the selection of the length and number of sections of the telescopic aerial work platform arm.

Description

TECHNICAL FIELD

[0001] The application relates to a design method for selecting the number of joints and the joint length of a telescopic aerial work vehicle arm, which can provide a quick, accurate and patternized selection design method for work arms of different lengths. BACKGROUND

[0002] The aerial work vehicle currently has four types of telescopic, folding, vertical lifting and hybrid types. At present, it is widely used in construction, fire fighting, urban municipal and other high-altitude operation fields. With the further acceleration of urbanization in China, the demand for high-rise and super high-rise building operations is further increased. The telescopic aerial work vehicle is currently widely used in municipal and urban operations, so the invention and design of the telescopic aerial work vehicle have a broad prospect.

[0003] At present, the telescopic aerial work vehicle has the following problems:

[0004] (1) The number of joints of the current work arm is not the same, and the work vehicle with a uniform height may have five or six joints. Different numbers of joints will affect the length of each joint, and then affect the joint length between the joints, so it is impossible to form a quick and effective selection criterion.

[0005] (2) The joint arm material of the aerial work vehicle is not the same, and with the increase of the yield strength, the thickness of the joint arm will gradually decrease, so the selection of the joint length of different materials is mostly selected by experience. The mechanical properties of the material cannot be fully utilized.

[0006] The application patent with the patent number CN104843616A and the publication date of August 19, 2015 discloses a kind of aerial work vehicle arm and its working radius control method, rotary supporting is connected with rotary table and chassis respectively, rotary reducer is arranged on rotary table, rotary reducer is connected with rotary supporting, arm, amplitude cylinder and rotary table are mutually hinged two by two;Rotary encoder is arranged on rotary table, lower pinion of rotary encoder rotating shaft is in mesh with the outer gear of rotary supporting;Horizontal inclination sensor and length sensor are installed on arm, controller is installed on rotary table;Horizontal inclination sensor, length sensor and rotary encoder are electrically connected with controller. The corresponding limit value of arm working radius R and rotary angle θ is pre-stored in the controller, by calculating rotary angle θ and working radius R, the controller compares the corresponding limit value of arm working radius R and rotary angle θ in real time, expands the working range of aerial work vehicle arm, fully utilizes the potential of aerial work vehicle, and achieves good results. However, the method only introduces the control method of the working radius of the arm of the aerial work vehicle, and does not mention how to mode select the arm length and the number of joints. SUMMARY

[0007] The purpose of the present application is to overcome the defects and deficiencies in the prior art, and to provide a selection method for the length and the number of sections of the telescopic aerial working vehicle arm which can maximize the utilization of the mechanical properties of the material, is fast and effective, and is patterned.

[0008] To achieve the above purpose, the technical solution of the present application is: a design method for selecting the number of sections and the length of the telescopic aerial working vehicle arm, comprising the following steps:

[0009] 1) When the full extension length of the working arm is 20-25m, a material with a yield strength not less than 800MPa is selected, and the length L of the single section arm is selected within 3.7m-4.5m; when the full extension length of the working arm is 15-20m, a material with a yield strength not less than 600MPa is selected, and the length L of the single section arm is selected within 3.5m-4.2m; when the full extension length of the working arm is 10-15m, a material with a yield strength not less than 500MPa is selected, and the length L of the single section arm is selected within 3.2m-3.9m;

[0010] 2) Under the condition that the rigidity and strength of the working arm meet the requirements and the length of the working arm is determined, the number I of sections of the arm is designed as a design parameter: when the full extension length of the working arm is 20-25m, the number I of sections of the arm is selected as 6 sections; when the full extension length of the working arm is 15-20m, the number I of sections of the arm is selected as 5 sections; when the full extension length of the working arm is 10-15m, the number I of sections of the arm is selected as 4 sections;

[0011] 3) Under the premise that the material, the length L and the number of sections of the arm are selected, the overlap length D between each section of the arm is designed as a parameter, and the value of the overlap length D between each section of the arm is related to the full extension length L of the working arm and the number I of sections of the arm: T

[0012]

[0013] L i is the length of the single section arm; L T is the full extension length of the working arm; I is the number of sections of the arm; K

[0014] is a coefficient, and the value range of K is: 2.5e-5

[0015] In the step 3), the overlap length D is optimized by the finite element analysis software under the condition that the overall deformation of the working arm is within the allowable range, so that the allowable requirements can be met under the premise of the minimum quality.

[0016] Compared with the prior art, the present application has the following beneficial effects:

[0017] ​1. The application combines experiments and simulation analysis, and summarizes the selection rule of the arm length under different operation heights, the node number selection corresponding to different arm lengths, and the lap length selection rule, thereby providing a fast and patternized selection method for the arm length, node number, and lap length selection of the overhead working vehicle.

[0018] 2. The application parameterizes the arm length, node number, and lap length of the single-node vehicle arm as L i , I, and D, can meet the parameter selection under different operation heights, and the method has universality and is applicable to the overhead working vehicles of different heights, thereby greatly reducing the test cycle of parameter design and selection. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is the arm length, lap, and total length schematic diagram of the six-node arm in the application;

[0020] Figure 2 is the arm length, lap, and total length schematic diagram of the five-node arm in the application;

[0021] Figure 3 is the arm length, lap, and total length schematic diagram of the four-node arm in the application;

[0022] Figure 4 is the stress nephogram of the application;

[0023] Figure 5 is the deformation nephogram of the application.

[0024] In the figure: vehicle arm 1, operation arm 2. DETAILED DESCRIPTION

[0025] The utility model will be further explained in detail in combination with the description of the drawings and the specific implementation.

[0026] Referring to Figures 1 to 3 , a design method for selecting the lap length and node number of the telescopic overhead working vehicle arm, comprising the following steps:

[0027] 1) when the full extension length of the operation arm 2 is 20-25 m, a material with a yield strength not less than 800 MPa is selected, at this time, the arm length L of the single-node vehicle arm 1 is selected within 3.7 m-4.5 m; when the full extension length of the operation arm 2 is 15-20 m, a material with a yield strength not less than 600 MPa is selected, at this time, the arm length L of the single-node vehicle arm 1 is selected between 3.5 m and 4.2 m; when the full extension length of the operation arm 2 is 10-15 m, a material with a yield strength not less than 500 MPa is selected, at this time, the arm length L of the single-node vehicle arm 1 is selected between 3.2 m and 3.9 m;

[0028] 2) In the case of ensuring the rigidity, strength of the working arm 2 and the length of the working arm 2, the number I of the sections of the vehicle arm 1 is taken as a design parameter: when the full length of the working arm 2 is 20-25m, the number I of the sections of the vehicle arm 1 is selected as 6 sections; when the full length of the working arm 2 is 15-20m, the number I of the sections of the vehicle arm 1 is selected as 5 sections; when the full length of the working arm 2 is 10-15m, the number I of the sections of the vehicle arm 1 is selected as 4 sections;

[0029] 3) In the case of selecting the material, length L of the vehicle arm 1 and determining the number of sections, the lap length D between each section of the vehicle arm 1 is taken as a parameter for design, and the lap length D between each section of the vehicle arm 1 is related to the full length L of the working arm 2 and the number I of the sections of the vehicle arm 1: T

[0030]

[0031] L i is the length of a single section of the vehicle arm 1; L T is the full length of the working arm 2; I is the number of sections of the vehicle arm 1; K is a coefficient, and the selected value range of K is 2.5e-5

[0032] In the step 3), the lap length D is optimized by the finite element analysis software in the case of ensuring that the overall deformation of the working arm 2 is within the allowable range, so that the allowable requirements can be met under the premise of the minimum quality.

[0033] In the application, all the vehicle arms 1 are extended to constitute the whole working arm 2.

[0034] In the application, in combination with the finite element analysis calculation, the selection of the vehicle arm 1 of the aerial work vehicle is related to the maximum working height thereof: when the total length of the working arm 2 of the aerial work vehicle is between 20-25m, the working height exceeds 23m, at this time, the length L of the vehicle arm 1 should be selected between 3.7m-4.5m; when the full length of the working arm 2 is 15-20m, the working height is greater than 18m and less than 23m, at this time, the length L should be selected between 3.5m-4.2m; when the full length of the working arm 2 is 10-15m, the working height is less than 18m, at this time, the length L should be selected between 3.2m-3.9m; in the selection of the length of the arm, the lengths of the arms of different arms basically follow the following rules: the length of the basic arm is less than that of the two-stretch arm, the lengths of the three-stretch arm and the four-stretch arm are less than that of the two-stretch arm and gradually decrease; the difference between the two-stretch arm and the basic arm is between 200-400mm; the differences between the two-stretch arm and the three-stretch arm, the three-stretch arm and the four-stretch arm and the four-stretch arm and the five-stretch arm are basically equal and are between 50-150mm.

[0035] ​The number of sections of the vehicle arm 1 is related to the length of the operation arm 2. When the operation height is greater than 23 m, the operation arm 2 is elongated by 20-25 m, and at this time, the number of sections I of the operation arm 2 is selected to be 6 sections. When the operation height is between 18 m and 23 m, and the total length of the operation arm is 15-20 m, at this time, the number of sections I of the operation arm 2 is selected to be 5 sections. When the operation height is less than 18 m, and the total length of the operation arm 2 is 10-15 m, at this time, the number of sections I of the operation arm 2 is selected to be 4 sections.

[0036] After the length and the number of sections of the operation arm are selected, in order to meet the requirements of rigidity and deformation, and in combination with the actual production and the working conditions, the lap length corresponding to the length of the different sections is selected according to the formula

[0037]

[0038] L i L is the length of the single-section vehicle arm 1; L T L is the total length of the operation arm 2; I is the number of sections; and K is a coefficient.

[0039] The lap length D: The value of the lap length D of each section is related to the total length of the elongated arm and the number of lap sections. Specifically, when the total length of the elongated arm is 20-25 m, the lap length

[0040] When the total length of the elongated arm is 15-20 m, the lap length

[0041] When the total length of the elongated arm is 10-15 m, the lap length

[0042] The range of the coefficient K is 2.5e-5 < K < 3e-5.

[0043] The coefficient is finally selected and determined in combination with the actual use. It is ensured that the lap length of each section meets the use requirements.

[0044] Example 1

[0045] The length of the single-section vehicle arm 1 is selected to be 4190 mm, the total length of the operation arm 2 is 21.2 m, at this time, the material used is 960 high-strength steel, and according to the formula The lap length D at this time is calculated to be 420 mm, and the rigidity and strength analysis is performed. It can be seen from the stress cloud and the deformation cloud in the drawings that the maximum stress and the deformation amount are within the required range.

[0046] The embodiments described above are only part of the embodiments of the present application, rather than all the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor are within the scope of protection of the present application.

Claims

1. A telescopic aerial work platform arm section number and length selection design method, comprising the following steps: 1) when the full length of the working arm (2) is 20-25 m, a material with a yield strength not less than 800 MPa is selected, and the length L of the single-section arm (1) is selected within 3.7-4.5 m; when the full length of the working arm (2) is 15-20 m, a material with a yield strength not less than 600 MPa is selected, and the length L of the single-section arm (1) is selected within 3.5-4.2 m; when the full length of the working arm (2) is 10-15 m, a material with a yield strength not less than 500 MPa is selected, and the length L of the single-section arm (1) is selected within 3.2-3.9 m; 2) under the condition that the rigidity and strength of the working arm (2) meet the requirements and the length of the working arm (2) is determined, the section number I of the arm (1) is taken as a design parameter for design: when the full length of the working arm (2) is 20-25 m, the section number I of the arm (1) is selected as 6 sections; when the full length of the working arm (2) is 15-20 m, the section number I of the arm (1) is selected as 5 sections; when the full length of the working arm (2) is 10-15 m, the section number I of the arm (1) is selected as 4 sections; 3) In the premise of the material, length L and the number of sections of the selected arm (1), the lap length D between each section of the arm (1) is designed as a parameter, and the value of the lap length D between each section of the arm (1) is related to the full length L of the working arm (2) and the number of sections I of the arm (1): T and the number of sections I of the arm (1): L i L is the length of the single-joint vehicle arm (1); L T L is the full length of the working arm (2); I is the number of joints of the vehicle arm (1); K is a coefficient, the value of K being in the range: 2.5e-5 < K < 3e-5.

2. The design method for selecting the number and length of arms of a telescopic overhead working vehicle according to claim 1, characterized in that: in step 3), the finite element analysis software is used to optimize the lap length D under the condition that the overall deformation of the working arm (2) is within the allowable range, so that the allowable requirements can be met under the premise of minimum quality.

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