Furniture operations mainly include carving, filing, sawing, scribing, drilling, reaming, tapping and threading (see thread processing), scraping, grinding, straightening, bending and riveting, etc. . Locksmithing is the oldest metal processing technique in mechanical manufacturing. After the 19th century, the development and popularization of various machine tools gradually mechanized and automated most benchwork operations. However, benchwork is still a widely used basic technology in the machinery manufacturing process. The reasons are: ① scribing, scraping, There is no suitable mechanized equipment that can replace all clamping operations such as grinding and mechanical assembly; ② Some of the most precise templates, molds, measuring tools and mating surfaces (such as guide rail surfaces and bearing bushes, etc.) still need to rely on the craftsmanship of workers to make precise Processing; ③ In the case of small batch production of single pieces, repair work or lack of equipment conditions, it is still an economical and practical method to use fitter to manufacture certain parts.
Main tasks Processing parts: Some processing that is not suitable or cannot be solved by mechanical methods can be completed by a fitter. Such as: marking during parts processing, precision machining (such as scraping, cutting templates and making molds, etc.), as well as inspection and repair, etc.
Vise
Assembly: The parts are assembled according to the assembly technical requirements of the mechanical equipment, and the parts are assembled and finally assembled, and after adjustment, inspection and test run, etc., they are made into qualified products. Mechanical equipment.
Equipment maintenance: When the machinery malfunctions during use, is damaged, or the accuracy decreases after long-term use, affecting its use, it must also be maintained and repaired by a fitter.
Tool manufacturing and repair: manufacturing and repairing various tools, fixtures, measuring tools, molds and various professional equipment.
Filing 1. Overview
In benchwork operations, filing plays a large proportion. It can be said that the manufacture of every workpiece is inseparable from filing. The processing range of filing is very wide. It can process the internal and external planes, internal and external curved surfaces, internal and external corners, grooves and various complex-shaped surfaces of the workpiece. Although modern technology develops rapidly, filing is still used to rest and repair individual parts during the assembly process, to process certain complex-shaped parts under small batch production conditions during the assembly process, and to make molds, etc. . It can be seen that filing still occupies a very important position in modern industrial production. There are many fine teeth and strips on the surface, a hand tool used for filing workpieces. Used for micro-processing of metal, wood, leather and other surface layers.
The application of files is very early. The oldest file discovered is a bronze file made in Egypt around 1500 BC.
Modern files are generally made of carbon steel through processes such as rolling, forging, annealing, grinding, chopping and quenching.
2. Materials
Commonly used materials for files are: carbon tool steel T12, T12A, T13A. The hardness after quenching can reach more than 62HRC
3. Structure And the names of each part
A. File body: The part between the tip of the file and the shoulder of the file is the file body. For plastic surgery files without file shoulders, the file body refers to the part with file lines.
B. File handle: the part other than the file body.
C. Parallel part of the file body: The part where the busbars of the file body are parallel to each other is the parallel part of the file body.
D. Tip: The part from the starting point where the cross-sectional size of the file body begins to gradually shrink to the tip. (The length of the file body = the length of the tip + the parallel part of the file body)
E. Main file pattern: The file pattern that plays the main cutting role on the file working surface is the main file pattern.
F. Secondary file pattern: The file pattern covered by the main file pattern is the auxiliary file pattern.
G. Edge file pattern: File the narrow edge or the file pattern on the narrow edge is the edge file pattern.
H. Main (auxiliary) file bevel angle λ (ω): The acute angle between the main (auxiliary) file line and the file body axis is the main (auxiliary) file bevel angle λ (ω).
I. Edge file bevel angle θ: The acute angle between the edge file pattern and the axis of the file body is the edge file bevel angle θ.
J. Number of file lines: The number of file lines per 10mm length along the axis of the file is the number of file lines.
K. Bottom line of file teeth: On the normal vertical section of the main file pattern, the straight line passing through the bottoms of two adjacent teeth is the line connecting the tooth bottoms.
L. Tooth height: The distance from the top of the tooth to the bottom of the tooth is the tooth height.
M. Tooth rake angle: The main file pattern passes through the normal surface of the tooth tip. The sharp angle between the intersection line of the file cutting edge surface and the normal surface and the vertical line connecting the tooth base is the tooth rake angle. front corner.
4. Type
Flat file
A. Fitter's file (ordinary file)
According to the roughness of the file body, the file body Different cross-sectional shapes can be divided into flat files, semi-circular files, triangular files, square files, round files, etc.
Shaping files
B. Special-shaped files
Used when processing special surfaces, divided into diamond-shaped files, single-sided triangular files, knife-shaped files, double semicircular, Oval, round belly files, etc.
C. Shaping file
Used to trim small parts on the workpiece.
5. Instructions for use
(1) Use one side of the new file first, and then use the other side after it is blunt.
(2) When rough filing, the effective full length of the file should be fully used, which can not only improve the filing efficiency, but also avoid local wear of the file teeth.
(3) The file must not be stained with oil or water.
(4) When filing, if the file chips are embedded in the gaps between the teeth, you must promptly use a wire brush or a thin iron sheet or copper sheet to remove the chips on the file teeth along the direction of the file teeth.
(5) Do not file the hard skin of rough parts or hardened workpieces. When filing soft metals such as aluminum and tin, a single-tooth file should be used.
(6) If there is hard skin or sand on the surface of the casting, it should be ground off with a grinding wheel or filed with a semi-sharp file or an old file before processing.
(7) Do not touch the filing surface with your hands during filing to avoid slipping when filing again.
(8) The file must be cleaned after use to avoid rust.
(9) Do not stack it with other tools or workpieces, nor overlap it with other files to avoid damaging the file teeth.
The use of files
6. Safety matters
(1) The file is a right-handed tool and should be placed on the right side of the vise and on the vise table The file handle should not be exposed outside the pliers table to prevent it from falling to the ground and injuring your feet or damaging the file.
(2) Files without handles or files with cracked handles cannot be used.
(3) When filing, the file handle must not hit the workpiece to avoid the file handle falling off and causing an accident.
(4) Do not blow the filing chips with your mouth, nor rub the filing surface with your hands.
(5) The file cannot be used as a pry bar or hand hammer.
7. Maintenance
(1) In order to prevent the file from wearing too fast, do not use the file to file the hard skin of the blank or the hardened surface of the workpiece, but use other tools first. Tools or use the front end and side teeth of a file cutter for processing.
(2) When filing, you should use one side of the file first, and then use the other side after this side is blunt. Because used file teeth are prone to rust.
(3) When filing, make full use of the effective working surface of the file to avoid local wear.
(4) Files cannot be used as tools for assembly, disassembly, knocking, and prying to prevent breakage due to the brittle material of the file.
(5) When using plastic files and small files, do not use too much force to prevent the file from breaking.
(6) The file must be waterproof and oil-proof. The file will easily rust after being exposed to water. The file is prone to slipping when working after being stained with oil.
(7) During the filing process, if chips are found embedded in the filing lines, they must be removed in time to prevent the chips from scratching the machined surface. After using the file, use a file brush or a copper blade to brush off the remaining chips along the file pattern to prevent rust. Never blow chips with your mouth to prevent them from flying into your eyes.
(8) When placing files, avoid collision with hard objects and avoid overlapping files to prevent damage to the files.
Features of fitter tools
Fitter has three major advantages (flexible processing, can process complex-shaped and high-precision parts, small investment) and two major disadvantages (low production efficiency and high labor intensity) , processing quality is unstable).
(1) Flexible processing In situations that are not suitable for mechanical processing, especially in the maintenance of mechanical equipment, fitter processing can achieve satisfactory results.
(2) Can process parts with complex shapes and high precision. Skilled fitters can process parts that are more precise and smooth than those processed by modern machine tools, and can process parts that even modern machine tools cannot process. Parts with very complex shapes, such as high-precision measuring tools, prototypes, molds with complex beginnings, etc.
(3) Invest in small benchwork tools and equipment that are cheap and easy to carry.
(4) Low production efficiency and high labor intensity.
(5) The processing quality is unstable. The processing quality is affected by the technical proficiency of the workers.
The scope of work mainly includes marking, processing parts, assembly, equipment maintenance and innovative technology.
(1) Mark the parts before processing.
(2) Processing parts The manufacturing of parts that are not suitable or cannot be solved by mechanical methods, as well as various tools, clamps, measuring tools and various special equipment, etc., must be completed by fitter work.
(3) Assembly: The machined parts are assembled, assembled and finally assembled according to the technical precision requirements of the machine to make it a complete machine. (4) Equipment maintenance: Parts of mechanical equipment that are damaged, malfunction during use, or lose accuracy after long-term use must be maintained and repaired by fitters.
(5) Innovative technology In order to improve labor productivity and product quality, continuous technological innovation and improvement of tools and processes are also important tasks for fitters. In short, fitter is an indispensable type of work in the machinery manufacturing industry.
Operational skills: marking, carving, sawing, filing, drilling, reaming, countersinking, reaming, tapping, threading, straightening and bending, riveting, scraping, grinding, Machine assembly and commissioning, equipment maintenance, measurement and simple heat treatment. The main tools of a fitter: A fitter is a skilled worker who assembles and repairs tools such as files, scrapers, hand drills, reamers, bench vises, small drill presses, and electric grinders.
Commonly used equipment: Fitter workbench, bench vise, grinder, benchtop drill press, vertical drill press, radial drill press
Category: Fitter (ordinary fitter): A person who assembles, trims, and processes parts.
Flat file
Mechanical fitter: Mainly engaged in the maintenance and repair of various mechanical equipment.
Tool fitter: Mainly engaged in the manufacture and repair of tools, molds, and knives.
There are two general categories of fitters: 1. Mechanical maintenance fitters 2. Assembly fitters (advanced fitters, mold fitters, tool fitters, repair fitters, machine repair fitters, scribing fitters, electrical fitters, scribing fitters, sheet metal fitters, installation fitters, etc.) But A fitter is a skilled worker who assembles and repairs tools such as files, drills, reamers, vises, and benches.
Application conditions: Junior (those who meet one of the following conditions)
(1) Have completed the required standard number of formal training hours in this profession and obtained a graduation (completion) certificate.
Plastic Surgery File
(2) Continuous internship in this profession for more than 2 years.
(3) The apprenticeship period in this profession has expired.
Intermediate (those who meet one of the following conditions)
(1) After obtaining the primary professional qualification certificate of this occupation, continuously working in this occupation for more than 3 years, and receiving intermediate formal training in this occupation Achieve the required number of standard hours and obtain a graduation (completion) certificate.
(2) After obtaining the primary professional qualification certificate for this profession, work in this profession continuously for more than 5 years.
(3) Have been engaged in this profession continuously for more than 7 years.
(4) Obtain a vocational (professional) graduation certificate from a secondary vocational school or above that is approved by the labor and social security administrative department and aims at cultivating intermediate skills.
Advanced (those who meet one of the following conditions)
(1) After obtaining the intermediate professional qualification certificate of this occupation, continuously working in this occupation for more than 4 years, and receiving advanced formal training in this occupation Achieve the required number of standard hours and obtain a graduation (completion) certificate.
(2) After obtaining the intermediate professional qualification certificate for this occupation, work in this occupation continuously for more than 7 years.
The use of files
(3) Graduation from a senior technical school or a higher vocational school with advanced skills as the training goal that has been reviewed and approved by the labor and social security administrative department. Certificate.
(4) Graduates of a college degree or above in this major or related majors have been engaged in this occupation for more than 2 years after obtaining the intermediate professional qualification certificate.
Technicians (those who meet one of the following conditions)
(1) After obtaining the senior professional qualification certificate of this profession, they have been working in this profession for more than 5 years continuously,