Design and standard of the most popular drive in s

Design and standard of drive in shelf

because of its own structural characteristics, the drive in shelf system should take into account many requirements such as storage goods, shelf material selection, strength, stiffness, stability and so on in the design and planning process. The upcoming "drive in shelf" industry standard has made clear provisions on relevant aspects, which is conducive to the development of the industry

drive in shelf, design, standard

drive in shelf is an assembled shelf in which forklifts drive in and out of the shelf and store goods in pallet units. The drive in shelf, also known as corridor shelf and through shelf, solves the problems of lack of utilization evaluation and too long formulation cycle of new material standards. It is a shelf structure form of multi door and pallet unitized goods connected by lattice column edge continuation, which stores one after another on the cantilever beam along the depth direction. This kind of shelf structure can share the forklift operation channel and goods storage space, which greatly improves the utilization rate of warehouse space and site area. However, the goods in the same operation channel cannot be first in first out. It is suitable for the storage of goods in large quantities, few varieties or in the operation channel that flow to the same customer, such as beverages, dairy products, tobacco, low-temperature frozen storage, standard household appliances, chemical industry, clothing and other industries. According to statistics, the drive in shelf can achieve the maximum storage density, the effective utilization rate of space can be increased to 90% at most, and the utilization rate of site area can reach more than 60%

with the increasingly extensive application of drive in shelves, it needs to be standardized by industry standards. At present, the industry standard of "drive in shelf" has been completed and will be promulgated with the strong support of China Logistics Technology Association and various manufacturers. This standard stipulates the terms, rated load and maximum load, material, structure, size, strength, stiffness, stability requirements, spraying quality requirements, testing methods, inspection rules, etc. of the drive in shelf. Its implementation will promote and standardize the development of China's shelf industry

standardization of pallet unit goods

the planning and design of the drive in shelf warehouse is first of all the standardization of pallet unit goods. The shelf structure and size should be determined according to the storage items and pallet size, and try to choose 1200 series pallets recommended in the national standard. Due to the high storage density of pallet unit goods in the drive in shelf and the integration of operation channel and storage space, there should be higher requirements for pallet quality and external dimension limit of pallet unit goods than other types of shelves; In addition, the weight of pallet unit goods should generally be controlled within 1600kg

on the basis of the above conditions, we can further carry out the general layout and structural design of the drive in shelf, as well as the warehouse planning and design combined with other shelves

structure of drive in shelf

the stress mode of drive in shelf structure is different from other types of shelf structures. The lattice column structure mainly bears lateral bending resistance, that is, the pallet unit goods are stored on the cantilever beam standing on the side of the lattice column structure, which acts on the goods on the single and double cantilever beams and the self weight of the shelf, generates the moment of the cantilever, and transmits it to the lattice column structure. Therefore, In the drive in shelf structure, the stability of the column structure is weak, and there are few reinforcement methods that can be achieved, which is also difficult to achieve

at present, the WAP shuttle trolley is used to replace the drive in shelf mode of forklift entering and leaving the roadway. At this time, the continuous bearing beam is used to replace the cantilever beam in the drive in shelf. It still maintains the unity of the working channel and the storage space, but improves the load-bearing capacity and stability of the shelf structure, which will become one of the forms of shelf design and planning in the future

the lattice column structure described in this paper is mainly composed of column members and supporting members (transverse and diagonal braces). Most column members adopt uniaxial symmetric cold-formed thin-walled and porous cross-section members, and most transverse and diagonal braces adopt cold-formed steel with C-section or cold-formed steel with other cross-sections; The column members are connected with horizontal and diagonal braces to form a structure through bolts; The pressure borne by the column members is shared by horizontal tension and diagonal bracing, which improves the safety of the whole structure

the semi-rigid or rigid connection between adjacent column members forms a multi door lattice shelf through the top beam structure, and the column member body is connected with the cantilever, cantilever beam or other components through the mechanical locking device; The base of the rack lattice column component is connected with the ground foundation through bolts or other forms

structural characteristics of the drive in shelf

the drive in shelf can be divided into three structures according to the picking direction: one-way drive in, two-way drive in and through. The total depth of the one-way drive in (wall area) shelf is best controlled within 7 pallet depths; The total depth of the rack area of the two-way drive in type (goods can be accessed on both sides separated by the middle area) should be controlled within 14 pallet depths to improve the efficiency and reliability of forklift access; The through type requires special consideration of the bending stability and cost performance of the rack portal structure, and it is generally not recommended to use it, unless there is a special need for site logistics planning

the drive in shelf system has typical characteristics of first in and last out storage; The forklift operation mode is mostly the continuous "high lift and high fight" mode. The center of gravity of the goods is high after being raised. The forklift is easy to shake with the unevenness of the channel ground and collide with the shelf, which will affect the stability and safety of the shelf structure. Therefore, the driver has high requirements for driving technology, and the turnover speed and efficiency of goods are also affected to a certain extent

the structural design of the drive in shelf is the most critical factor to determine the quality of the shelf. In addition, the material, production process, production equipment, tooling fixtures and electrostatic spraying of the shelf will directly affect the quality and grade of the shelf. The main structure of the shelf is a multi statically indeterminate space steel structure. It is quite cumbersome to calculate its strength, stiffness and stability by traditional classical mechanical methods or dynamic methods. A simplified calculation model can be used to analyze and optimize the design in combination with domestic and foreign standards and specifications and test data. At present, the structural strength analysis and stability analysis of finite element are mostly used for auxiliary design and full-scale load test verification

the drive in shelf is a portal structure. In order to ensure its stability, the slenderness ratio of columns should not be too high. It should generally be controlled within 10 meters, and it is appropriate to have more than 4 layers and 3~5 columns. Compared with pallet shelves of the same category, in addition to the steel section specification, it is also necessary to add tensile structural members. The main accessories of the drive in shelf include column piece, cantilever and cantilever beam, top beam, top diagonal rod, back diagonal rod, walking guide rail, foot guard or bollard (protective part of the front channel opening of the shelf), as shown in Figure 3

the basic dimension of the design of the drive in shelf

w is the pallet width dimension oriented by the forklift. It is one of the important parameters of the design of the drive in shelf, which directly affects other dimensions of the shelf and the operable space of the forklift; W1 is the effective travel distance of forklift, which directly determines the width of forklift body (usually the width of forklift body is less than w1-100mm); W2 is the distance between the center lines of two adjacent columns of the channel; W3 is the effective length of the cantilever. The larger the effective length of the cantilever is, the greater the bending torque the column piece is subjected to, and the smaller the bearing capacity of the column piece of the same specification, that is, it affects the overall bearing capacity of the shelf, generally W3 ≥ 210mm; W4 is the carrying size of the pallet on the cantilever beam, which is related to the safety of the pallet access process. Generally, W4 ≥ 130mm; W5 refers to the gap between the goods and the column piece predicted by the standing analysts, which affects the safety of the goods on the column piece and the swing degree of the forklift. Generally, W5 ≥ 75mm

design of drive in shelf

in the design process of drive in shelf, we must first standardize the pallet unit goods, and determine the specification, size, stacking height and rated load capacity of the pallet; Then we can plan the overall structure of the drive in shelf and the key dimensions of the storage unit, such as span, depth, layer spacing, height, etc., and design and review the shelf structure and parts. During the design, the design verification or test verification shall be carried out for the key parameters, and the corresponding mechanical simplified model shall be established according to the case structure. According to the actual stress (including seismic load, etc.) and load distribution of the shelf, combined with the corresponding geometric parameters and quality characteristics of the member section, the design and verification of strength, stiffness and stability shall be carried out. If necessary, the experimental verification can be carried out to ensure that the design results are consistent with the reality

for example, in a cold storage project of Tianpeng food group, Shanghai Guobao Dinghu group determined that the weight of goods was 1000kg/pallet and the basic parameter of pallet unit was w1200 through detailed communication with customers, field measurement and comparison of planning schemes × D1000 × H1200mm, perennial -18 ℃ low temperature storage. Finally, the drive in shelf is selected as the main storage form of the warehouse, supplemented by a small number of beam shelves, to meet the requirements that some goods need to be picked out of the warehouse, and to maximize the requirements of customers for the large capacity of the cold storage. Finally, the space utilization rate of the cold storage is about 67%, realizing the storage capacity of 19140 pallet positions in three-tier storage

other standards related to the design of drive in shelf

in the steel structure of drive in shelf, there are mainly two types of structural members, one is hot-rolled steel and steel plate composite members, and the corresponding main design specification is code for design of steel structures GB; The other is cold-formed steel, especially cold-formed thin-walled steel, which is formed by cold-formed steel sheets, steel strips, steel plates or flat steel bars. The corresponding main design specification is the technical specification for cold-formed thin-walled steel structures GB

the reference standards in terms of size, shape, etc. of section steel are "size, shape, weight and allowable deviation of cold-formed hollow section steel for structure gb/t", "size, shape, weight and allowable deviation of general cold-formed open section steel gb/t"; In terms of materials, reference standards include cold rolled steel strip bzj for welded pipe, cold rolled low carbon steel plate and steel strip BQB, hot rolled steel plate and steel strip BQB for structure, cold rolled low carbon steel plate and steel strip bzj, cold rolled carbon steel plate and steel strip bzj and rolled steel materials for general structure, etc; There are also some specifications in terms of structural welding, such as "overall dimensions of steel structure welds", "construction specification for steel structure fabrication and installation", etc

shelf steel structure is an edge application industry that involves a wide range of aspects and has an imperfect application theoretical system. At present, the main application specifications at home and abroad include code for design of steel shelf structure (cecs23:90), JB/T technical conditions for welded steel structure shelves in three-dimensional warehouses, JB/T code for design of high-rise rack warehouses with rail tunnels, etc. The standards related to pallet shelf warehouse in European standard FEM include US industrial shelf work example, US shelf work example, fem10.2.03. Specification (code), FEM 10.3.01. Tolerance deflection and clearance of cross beam adjustable pallet shelf, fem10.2.04. User specification (code), etc; American standards include ANSI/mh10. Safety code for use of industrial and commercial steel shelves, mh16.1-2004 Standard Code for design, testing and application of steel shelves for industrial storage, etc; Japanese shelf standards include JIS Z industrial shelf terminology, JIS Z industrial shelf, JIS Z through shelf with good sample breakpoints, JIS B General rules for automated warehouse design, etc. There is not much content to define and explain the drive in shelf separately