1 wheel part
1.1 wheel casting
The wheel material is cast steel and the grade is ZG310-570..
A. Familiar with drawing requirements and process analysis: before designing casting process, we should be familiar with drawing and related technical conditions, and have a comprehensive understanding of casting structure, size, technical requirements, number of parts, materials, weight and delivery cycle, etc., and then carry out technological analysis of the casting process under the given structural conditions. Considering the main defects that may occur in the casting process, corresponding technological measures should be taken to prevent them in the process design to ensure the casting quality and simplify the technological process.
B. Guarantee the quality of the castings: the structure of the castings wall, fillet, rib plate and groove are connected and matched each other, the connection of the castings wall should be reasonable, the casting inner and outer fillet and transition size should adopt gradual transition and larger fillet connection, avoid sudden change, cause stress concentration, cause cracks and other defects. The wall thickness should be uniform to avoid the formation of hot nodes and the warping deformation of the castings should also be prevented. Because the thickness of the outer edge and inner wall of the castings is different, and the cooling conditions of each part are different, it is easy to cause greater internal stress. Therefore, artificial aging and reverse deformation pattern should be adopted to avoid the warping deformation.
The kiln wheels are made of intermediate frequency furnace and cast by sand mold. Cast wheel surface can not have air hole, shrinkage hole, slag, sand and other quality defects, but also can not have hot crack, cold crack, loose and other quality problems, can not meet the quality requirements of the wheel, is strictly prohibited to use.
1.2 wheel and axle processing and bearing assembly
After casting, the wheels must be treated by normalizing and tempering, and important wheels must be quenched.
Wheel processing, the wheel edge and hole must meet the concentric requirements, its coaxiality allowable deviation must not exceed 0.10 mm.
The outer rim of the wheel must not be bouncing. The permissible deviation of the runout value should not exceed 0.30mm; the end faces of the wheels must be perpendicular to the outer edge and the center line of the inner hole, and the Perpendicularity Error should be controlled within the range of 0.1mm.
The size of the key parts of the wheel must be well controlled, and the cumulative error is not allowed to be transferred to the key size parts.
Wheel bearing selection of high-quality national standard products, bearing temperature requirements in reverse order to meet the requirements of the design drawings.
High temperature grease for boron nitride and high temperature grease must be used in bearing and wheel filling holes.
The shaft must be of high quality 45 carbon steel. The bearings at both ends of the shaft must be concentric, and the thimble pin axle lathe pin is used to ensure that the coaxiality does not exceed 0.10mm. Linear, plane and symmetrical requirements of both ends of the bearing seat are strictly controlled according to design or international standards to ensure that there is no distortion during assembly.
When the axle seat is machined, the size must be strictly controlled by the mould.
Safety of 2 steel frame
2.1 process flow
Familiar with Drawing Technical Requirements - Material Preparation - Steel Correction - Shedding - Assembly Welding - Residual Deformation Correction after Welding
2.2 steel correction
In the process of rolling, transportation and stacking, steel often produces surface unevenness or bending, distortion, deformation and other phenomena, especially thin steel plate and section steel with small cross-section, which are more likely to be deformed. The existence of these deformations will make the scribing line not reach the required accuracy and hinder the cutting work of automatic cutting machine. All steel products whose deformation exceeds the error value must be corrected before they are crossed.
2.3 blanking
Firstly, the structural shape and dimension on the design drawing are expanded into plane shape and dimension, which are directly drawn on the steel at the ratio of 1:1, and then cut. In this process, gas cutting and mechanical cutting are used.
All kinds of materials used in kiln trucks must be laid flat and straightened before cutting. Small section steel should be cut by grinding wheel cutting machine to ensure that the incision is neat and smooth. Large section steel should be cut by air cutting tool. The incision must be smooth and polished by hand-held grinding wheel. Rust, oxide scale and iron slag near the incision should be removed. And other residues to ensure the cleanliness of welding parts and avoid porosity defects during welding.
2.4 assembly welding
Before assembling, the steel structure of kiln car should first install a platform. The platform surface should be laid with medium-thick steel plate. The surface of the platform should be flat, no weld nodules and welding slag. The four corners of the platform and the middle parts should be in the same plane, that is, the measured elevation reading is consistent, and the error should not exceed 1 mm.
After the platform is installed in place, the standard mold can be made according to the size of the design drawings, and the dimensions of each part can be strictly controlled by the mold. The control dimensions include: the diagonal line of the kiln car, the central line of the kiln car, the central line of the axle and so on.
Because the parts on the steel structure of the kiln car are made of raw materials through the cutting and rectification processes, the parts have low accuracy and poor interchangeability. Some parts may need to be selected and adjusted during assembly, and sand machine may be used to repair them if necessary.
The steel components of the kiln car are welded together, so if problems are found after assembly and welding, the original parts can not be disassembled. If these problems can not be repaired, the whole kiln car will be scrapped, so the assembly sequence and quality should be carefully considered and strict requirements. In the production process, fully understand the technical requirements of the drawings in advance, assembly sequence strictly according to the construction organization design process design documents.
Because there are a lot of positioning welds in the assembling parts and a lot of welding work after assembling, it is necessary to master the characteristics of welding stress and component deformation, and take appropriate measures to prevent or reduce deformation and improve assembly quality.
Before welding kiln car parts, we must fully understand the design intent and solder every small part according to the design drawings. First spot welding, spot welding firmly, then segmental welding or full welding.
No cracks, burning through, slag inclusion, no penetration and other quality defects shall be found in the weld. The welding quality shall conform to the JB / ZQ400.3-86 and relevant national machinery manufacturing standards, as well as the provisions of JGJ82-199.
The height of the weld shall not be less than the minimum wall thickness of the welded part, and there shall be no distortion, warpage, deformation and other phenomena after welding.
Before mass production of kiln trucks, two prototypes should be assembled and welded, and the dimensions of the support frame and the plane elevation of the welded kiln trucks should be checked again. The dimension error of steel frame height is <2 mm, the length and width of kiln car are <2 mm, and the diagonal dimension error is <3.5 mm. If the prototype can meet the quality control requirement, it can be produced in large quantities.
3 kiln car assembly
Kiln car assembly should be carried out on acceptable track. The rail elevation error can not exceed 1 mm in both longitudinal and lateral directions, and the allowable error between the track and the center line is not more than (+1 mm), so that the wheel spacing can be ensured and all the wheels can land at the same plane height.
Carefully check all parts before assembly and meet the quality requirement. When installing kiln wheels, the longitudinal and horizontal directions must be adjusted to ensure that the longitudinal and lateral directions of the wheels are on the same axis. Wheel rotation should be flexible and running smoothly on the track. Single contract wheels and double contract wheels should pay special attention to the groove edge must be parallel to the track, never allow the phenomenon of biting track.
When welding and assembling the sand sealing plate, the verticality of the surface of the sand sealing plate should be well controlled. The clearance between the front and rear kiln car sand sealing plates should be uniform, the seam width should be about 5mm, and the upper and lower widths should be uniform. The sand seal plate of the front and back kiln car should be neat, and there should be no obvious wrong teeth.
The front and rear seal boxes must be corresponding to each other to ensure the sealing effect.
The panel of the kiln car should be laid flat without obvious bumps or sunken joints, and the welding must be firm.
After the assembly of the kiln car assembly is finished, remove rust and spray red Dan for two times, then brush black boiler paint.
Lining of 4 kiln car
The steel structure of the kiln car should be inspected strictly before the kiln car is built. The inspecting contents include: diagonal dimension, elevation of the four corners of the kiln car, whether the center line at both ends meets the design requirements of the drawings, whether the kiln car is flexible in operation, whether the various items are qualified before the kiln car can be built, and the brick entry of various types of kiln car before the building. Check and pre arrange the dimensions.
4.1 construction sequence
The purpose of this process is to leveling the frame bricks around the kiln car. The raw materials must be weighed according to the mix ratio required by the design before pouring. To determine the quality of raw materials needed for each plate of concrete, the water cement ratio should be well controlled during mixing, neither too thick nor too thin, and the installation of concrete surface frame brick should be well controlled during pouring.
Masonry and installation of frame brick: In the kiln car divided into the center line, first determine the kiln car corner of the frame brick size and elevation, and then vertical and horizontal simultaneous masonry and installation, masonry mortar must be full.
Laying of the ordinary needle-punched blanket insulation layer at the bottom of the kiln car: First clean the kiln car surface, the thickness of the process insulation layer is 20 mm, should be laid according to the design requirements, laying should be staggered seam laying dense, to ensure the kiln car insulation effect.
Casting refractory concrete for kiln truck: This process must be based on the design requirements of concrete proportion, control the water cement ratio, pouring refractory concrete must be compact, while strictly controlling the concrete surface height and flatness, in order to facilitate the next process, kiln truck pad brick installation.
Installation of padding brick on kiln car table: After curing the kiln car refractory concrete according to the regulations, clean the car table, install padding brick on kiln car table according to the design size and requirements of the diagram, ensure that the whole table flatness error is less than 0.8 mm.
Cleaning: After the kiln truck is built, the kiln truck table is cleaned as a whole, the mud, brick and other debris are swept clean, and the construction quality is checked by oneself. After the quality requirements are met, the supervision shall be submitted for acceptance.