1. Understand the general process of mechanical manufacturing.
2. Understand common metal materials.
3, understand the composition of commonly used measuring tools and master the use method.
4. Understand the basic knowledge of metal parts processing
5. Understand the basic concepts of limit and fit and surface roughness.
6. Understand the significance of safe production.
7. Understand the appearance and shape of various machine tools including lathes, milling machines, grinders, planers, boring machines, drilling machines, punches and slotting machines, as well as the basic operations of lathe, fitter, miller, grinder and planer included in the basic types of metal parts processing.
second, internship time: June 17, 29, June 19, 29
third, internship location: Shandong Linyi Lingong Automobile Axle Box Co., Ltd., Pingyi County, Linyi City, Shandong Province
fourth, internship unit and department: Shandong Linyi Lingong Automobile Axle Box Co., Ltd.
fifth, internship content:
(1 The company is located at the foot of Mengshan Mountain with beautiful scenery, covering an area of 185, square meters, with total assets of 5 million yuan and more than 1,2 employees, including 396 engineers and technicians.
the company's leading products: three platforms
● The annual production and sales of light automobile transmissions is 35, units, ranking first in China. Mainly for FAW Hongta, Second Automobile Light, Beiqi Foton, Beijing FAW, Hefei Jianghuai, Shenyang Jinbei, Chang 'an Leap, Dong 'an Panther, Ziqi Tangjun, Kema Automobile and other well-known domestic automobile manufacturers. The products are exported to the United States, Japan, Russia, India, Iran, Algeria and other countries with the OEM.
● The domestic market share of drive axle box of wheat, rice, corn and soybean combine harvester is 8%, and the technology is the leader in the industry. Mainly for Futian Lovo Heavy Industry, China Harvest, Xinlian, Jinyi, Yituo and other large domestic agricultural equipment machinery manufacturers.
● The hydraulic torque converter, gearbox, front and rear axle assemblies and their parts of construction machinery are mainly provided by large domestic construction machinery manufacturing companies such as Shandong Lingong and Futian Lovo Heavy Industry.
the company always adheres to the concept of "harmony, honesty, innovation and development" and constantly improves the management mechanism and modern enterprise system. Adhere to people-oriented and scientific development. The company has successively passed ISO 91: 2, ISO/TS 16949: 22 quality management system certification and China automobile product certification; Have the right to import and export; It is the holding party's national technical center sub-center, China Gear Professional Association's harvesting machinery variable speed transmission technology center, the national second-class safety and quality standardization enterprise, China's top 1 auto parts and gears industry, China's patent Shandong star enterprise, Shandong famous brand products, Shandong high-tech enterprises, Shandong machinery industry's top ten independent innovation brands, and the national torch plan of MW525G automobile transmission.
the company plans to build a domestic large-scale bridge box production base with annual production and sales of 6, sets of various bridge boxes and sales income of 2 billion yuan in the next three years (21-212). We warmly welcome you to our company for guidance and business negotiation.
(2) product understanding
28 rice harvester drive axle (not shown)
The overall design of the drive axle assembly is super strong; Large capacity clutch; Strong bearing capacity; Good handling performance; Hydraulic/mechanical braking steering is flexible and reliable; It is an ideal supporting product for the existing 1.8-2.2m cut crawler rice harvester.
main performance parameters:
input torque: 2N.m
matching power: 49, 495
matching model: 1.8-2.2m rice harvester
weight: 175Kg
515 automobile transmission (not shown)
standard international gear, v. Single slide shift control; All-aluminum/cast iron shell can be selected in two States, which is the preferred transmission for micro-passengers and micro-cards in China.
main performance parameters:
center distance: 7mm
input torque: 15N.m
matching power: 38, 385, 48
matching models: Jianghuai, Dongfeng, Futian, Dong 'an Panther and other micro-trucks, Dongfeng Xiaokang minibus
weight: 4Kg (. 3Kg (aluminum)
ZL5 drive axle (not shown)
① Main technical parameters
Speed ratio: 23.257
Main reduction ratio: 5.2857
Wheel side reduction ratio: 4.4
Maximum input torque: 5N.m
Maximum static load. The semi-axle is fully floating, and the clamp disc braking is reliable. The drive axle is a two-stage reduction transmission structure. The first stage is the main reduction gear, which is driven by Gleason spiral bevel gear, which has the characteristics of large input torque, high transmission efficiency and stable work. The second stage is the wheel-side reduction transmission device, which adopts planetary reduction transmission structure (NGW type), with good overall movement rigidity and stable output speed. Between the main speed reducer and the wheel side speed reducer, a fully floating semi-shaft connection is adopted to transmit power. The axle shaft has a certain floating amount in the axle housing, which overcomes the influence of axle housing deformation on the axle shaft. It can also be matched with vibration roller, tractor and other hosts. It is an ideal accessory product for popular loaders and other construction machinery under the same conditions
(3) Overview of machinery manufacturing process
Any machine or equipment is composed of corresponding parts and equipment. Parts can be made directly from profiles by cutting. In general, raw materials are made into blanks by casting, forging, stamping, welding and other methods, and then made from blanks by cutting. Some parts need to be interspersed with different heat treatment processes during the blank manufacturing and processing. Therefore, the general mechanical production process can be briefly summarized as: blank manufacturing-cutting-assembly and debugging
1) blank manufacturing
The common blank manufacturing methods are:
1. Casting molten metal, making molds, pouring molten metal into the molds, and solidifying to obtain castings with certain shapes and properties.
2. Forging is a processing method that under the action of pressure equipment and tools (dies), the blank is plastically deformed to obtain forgings with a certain geometric size, shape and quality.
3. Stamping A method of applying pressure to a sheet on a press to separate or deform it, so as to obtain a product (stamping part) with a certain shape and size. Stamping products have enough precision and surface quality, and can be used directly with little (even no) cutting.
4. Welding is a processing method that uses heating or pressure or both * * * with or without filler to achieve atomic bonding of weldments.
the shape of the blank is similar to that of the part, and the external size of the part to be machined is larger than the corresponding size of the part, while the hole size is smaller than the corresponding size of the part. The difference between the blank size and the parts is the machining allowance of the blank.
advanced casting and forging methods can also be used to directly produce parts.
2) Cutting
In order to make the parts reach the precise size and smooth surface, the machining allowance on the blank should be cut off by cutting. The common methods are turning, milling, planing, grinding, drilling and boring. Generally speaking, a blank must go through several cutting processes to become a finished part. Due to the need of technology, these processes can be divided into rough machining, semi-finish machining and finish machining.
in the process of blank manufacturing and cutting, in order to facilitate cutting and ensure the mechanical properties of parts, it is necessary to heat treat the workpiece before (or after) some processes. The so-called heat treatment refers to a technological method that metal materials (workpieces) are heated, insulated and cooled in an appropriate way to obtain the required structure and properties. After heat treatment, the workpiece may have a little deformation or surface oxidation, so finishing (such as grinding) is often arranged after the final heat treatment.
lathe is the main instrument of lathe, and lathe is a machine tool that mainly turns rotating workpieces with lathe tools. On the lathe, drills, reamers, taps, dies and knurling tools can also be used for corresponding processing. Lathe is mainly used to process shafts, disks, sleeves and other workpieces with revolving surfaces, and it is the most widely used machine tool in machinery manufacturing and repair plants.
turning tools can be divided into cylindrical turning tools, internal turning tools, cutting and grooving tools, threaded turning tools and forming turning tools according to their uses. Generally, turning has two steps: rough turning and fine turning. The purpose of rough turning is to cut off most of the machining allowance from the workpiece as soon as possible, so that the workpiece is close to the final shape and size. The purpose of finish turning is to cut off the machining allowance left by rough turning and ensure the dimensional tolerance and surface roughness of parts.
in addition, the CNC lathe comprehensively applies the knowledge of computer technology, automatic control, precision measurement and mechanical design, etc. It is a highly automated lathe controlled by an electronic computer, which has wide versatility and greater flexibility. It expresses all kinds of operations and steps needed in the machining process with digital codes, and sends digital information to a special general-purpose computer through the control medium. The computer processes and calculates the input information, and issues various instructions to control the servo system or other execution files of the lathe. A remarkable difference between CNC lathe and other lathes is that when the machining object changes, except for reinstalling the workpiece, it is only necessary to re-enter a new program without making any adjustments to the lathe.
Milling is a method that a miller uses a rotary milling cutter to cut various surfaces or grooves on a workpiece. Milling is one of the commonly used methods in metal cutting. Milling is mainly used for machining plane and various groove surfaces and forming surfaces, etc. Universal dividing head can also be used for milling indexing parts, and holes in workpieces can also be drilled or bored. Commonly used milling machines include vertical milling machine, horizontal milling machine and universal horizontal milling machine. Milling workers can be used for milling planes, inclined planes, stepped surfaces, grooves, spiral grooves and equally divided parts (machining gears).
The method that planers use planers to process workpieces on planers is called planing, which is one of the commonly used methods in metal cutting. The main motion of planing is linear reciprocating motion, mainly processing plane and groove (such as straight groove, T-groove and dovetail groove) and other parts. The main types of planers are shaper and gantry planer. The shaper is mainly used to process the surfaces of smaller parts, while the gantry planer is mainly used to process the surfaces of larger boxes, brackets, machine beds and other parts. Planers are generally made into elbows so that they will not bite into the machined surface of the workpiece and damage the blade and machined surface. The slotting machine is actually a vertical shaper, which is mainly used for machining the inner surface of workpieces, such as square holes, rectangular holes, polygonal holes and keyways in holes.
grinding is a method to process the surface of workpiece with grinding tools at a high linear speed, which is one of the main methods to process mechanical parts. Grinders mainly use grinding machines, which are mainly used for finishing internal and external cylindrical surfaces, internal and external conical surfaces, planes and forming surfaces (such as flower keys, threads and gears) of parts, so as to obtain higher dimensional accuracy and smaller surface roughness. Among them, the grinding wheel is the main working part of the grinder, and the cutting fluid is mainly used to reduce the temperature in the grinding area and reduce the friction between the grinding wheel and the workpiece.
fitter fitter mainly uses bench vise, various hand tools and some mechanical electric tools to finish the processing of some parts, the assembly and debugging of parts and machines, and the maintenance and repair of various mechanical equipment. The fitter is a complicated, meticulous and demanding job, and its basic operations include: parts measurement, marking, chiseling, sawing, filing, drilling, reaming, tapping, threading, scraping, grinding, straightening, bending, riveting, sheet metal blanking and assembly. Fitter can be divided into general fitter, marking fitter, repair fitter, assembly fitter, mold fitter, tool model fitter and sheet metal fitter.
when filing different shapes, different filing methods are needed, among which plane filing is the most basic filing, and there are also curved surface filing and through-hole filing.
3) assembly and debugging
according to the technical requirements of mechanical products, the parts that have been processed and passed the inspection are assembled, connected and fixed in a certain order by the method of fitter or the combination of fitter and machinery to become the whole machine. This process is called assembly. Assembly is the last process of mechanical manufacturing, and it is also the key to ensure that the machinery meets all technical requirements.
The assembled machine has to go through trial operation to observe its efficiency and overall quality under working conditions. Only after the inspection and test run are qualified can they be packed and shipped from the factory.
(4) Common knowledge of metal materials
1) Properties of metal materials
The properties of metal materials can be divided into two categories: service performance and process performance. Practical properties reflect the characteristics of materials in use, such as physical properties, chemical properties, mechanical properties, etc. Technological properties can reflect the characteristics of materials in processing and manufacturing.
1. Mechanical properties of metal materials Any machine part can bear the action of external force (load) when working. Therefore, the characteristics of materials under the action of external forces are particularly important. This property is called mechanical property. The mechanical properties mainly include strength, plasticity, hardness and toughness.
2. Technological properties of metal materials The technological properties of metal materials mainly include castability, forging, weldability and machinability.
2) Classification of metallic materials
Non-alloy steel (commonly known as carbon steel, Carbon steel for short)
steel low alloy steel
iron and alloy alloy steel based on iron
(mainly refers to steel materials) cast iron
metal materials ferroalloy
aluminum and aluminum alloy
non-ferrous metal materials (mainly refers to non-ferrous metals) copper and copper alloys
titanium and titanium alloys
3) Brief introduction of metal materials
1. Steel can be divided into non-alloy steel, low-alloy steel and alloy steel according to chemical composition. Non-alloy steel is commonly known as carbon steel or carbon steel for short. Carbon steel is divided into ordinary quality carbon steel, high quality carbon steel and special quality carbon steel according to the main quality grade and main performance or service characteristics of steel; According to the different carbon content, carbon steel can be divided into low carbon steel, medium carbon steel and high carbon steel.
ordinary quality carbon steel Q235A is used for making screws, nuts and washers.
High-quality carbon steel 8F steel and 1 steel are used to make stamped shells, containers, covers, etc. 4 steel shaft, rod; 45 steel to make gears, connecting rods, etc.
Special quality carbon steel mainly includes carbon tool steel, carbon spring steel and special free-cutting steel. T7 steel and T8 steel are used to make pliers, chisel, hammer, screwdriver, etc. T1 steel is used to make hand saw blades; T12 steel is used to make files and scrapers.
Low carbon steel (carbon content below .25%) has low strength, good plasticity and toughness, easy forming and good weldability, and is often used to make structures and parts with little stress.
Medium carbon steel (with carbon content between .25% and .6%) has high strength, certain plasticity and toughness, and is suitable for manufacturing mechanical parts. <