No matter in school or in society, many people have had the experience of writing papers and are familiar with them. Writing papers can cultivate our scientific research ability. Do you know how to write a good paper? The following is a sample essay of an assembly fitter technician that I collected for you. Welcome to share.

Thesis title:

Discussion on the technical points of assembly fitter

abstract:

Fitter is one of the five traditional jobs, and assembly fitter is also the last process of product processing and manufacturing. Because of the particularity of locksmith, it has been replaced by high-speed mechanized machining in many aspects. But for some special parts, fitter is essential, and fitter still plays a very important role in mechanical processing and manufacturing. Mastering the technical points of assembly fitter is also a compulsory course for a machine manufacturer.

Key words:

Assembly fitter; Fitter skills; Technical points; Replacement tool

1, assembly fitter skills

1 and 1 intersect.

Scribing is the operation process of drawing processing boundaries or drawing points, lines and surfaces as benchmarks on a blank or semi-finished product according to drawings and technical requirements. Tools include marking needle, compass, marking disk, steel ruler, sample punch, etc. Scribing requires clear and uniform lines, accurate fixed-length positioning size, and the accuracy is generally 0.25 mm ~ 0.05 mm. Scribing can determine the machining allowance of the workpiece, make the machining have obvious size boundaries, and also find and deal with unqualified blanks.

The marking tool should be separated from the blank, so as to avoid the burr of the blank scratching the marking tool and affecting the accuracy of the tool. At the same time, it should be maintained in time to avoid rust of tools. The steps of marking are usually as follows:

A, understand the drawings, know the parts of the workpiece that need to be marked in detail, clarify the functions and requirements of the workpiece and marking related parts, and understand the related processing technology;

B, selecting a marking benchmark;

C, preliminarily checking the error of the blank, and coloring the blank;

D, correctly install the workpiece and select the marking tool;

E, marking;

F, check the accuracy of the drawings in detail to see if there are any omissions;

G. punch holes in the line.

1 2 archive

Filing is widely used, which can file complex surfaces such as plane, curved surface, inner and outer surfaces and grooves. Whether the file is held correctly or not has a certain influence on the quality of the file, the exertion of the file strength and the fatigue degree of people. Precautions for archiving:

A, the file handle should be firm, don't use a file with a crack in the file handle;

B, are not allowed to blow iron filings with your mouth, and are not allowed to clean iron filings by hand;

C, file placement shall not show the clip table;

D, when clamping the machined surface, use a protective sheet, and add a wooden pad to the larger workpiece.

1.3 sawing

Sawing is a processing method of cutting or sawing materials or workpieces with a saw. Skills and methods: Hold the handle of the saw bow with the right hand, press the thumb on the index finger, control the direction of the saw bow with the left hand, put the thumb on the back of the bow, and hold the index finger, middle finger and ring finger at the front end of the saw bow. The posture is basically the same as that of filing. Matters needing attention when sawing:

A, when the workpiece is to be sawed off, reduce the pressure to prevent the foot from being hurt when the workpiece breaks;

B, when sawing, control the strength to prevent the saw blade from suddenly breaking out of control, causing injuries;

C, in the process of sawing, the vertical line of the saw blade should overlap, so as to avoid twisting;

D, the saw blade is installed too tightly or moves too fast, and the pressure is too high, so it is easy to break the saw blade.

1 4 drilling

When drilling on a drilling machine, the rotary motion of the drill bit is the main motion, and the axial motion of the drill bit is the feed motion. When drilling, first draw the cross center line of the hole at the drilling position and punch the center hole. The machining size is required to be small, and the center of the hole coincides with the intersection point. Reduce the friction between the small bit and the hole, improve the life of the small bit and improve the surface quality of the hole, and add enough cutting fluid when drilling. Precautions are as follows:

A, strictly abide by the operating rules of drilling machine, it is forbidden to wear gloves;

B, need to test in the process of drilling, must first stop, and then test;

C, when drilling, the end face of the flat-nose pliers handle should be placed in the left direction of the drilling machine workbench to prevent the flat-nose pliers from falling to the ground and hurting people;

D, when drilling a big hole, first use a small drill to drill the hole, and then use a big drill to enlarge the hole.

1.5 tapping thread

The machining method of cutting internal thread in workpiece hole with tap is called tapping. The workpiece is shown in figure 1, and 4×M 10 thread needs to be processed. First, drill a 4×M 10 pilot hole with φ 18mm (the drilling angle is 90), meanwhile chamfer the orifice of C 1.5, then drill a 4×M 10 bottom hole, and finally tap 4×M 10.

Matters needing attention when tapping threads:

A, chamfering the bottom hole orifice before opening;

B, the workpiece clamping position should be straight, so that the center line of the screw hole is in a vertical or horizontal position;

C, when the tap cuts into 1 ~ 2 turns, check and correct the vertical position of the tap in time;

D, tapping hole, often need to quit the tap, the iron filings in the hole, otherwise the tap will be broken due to iron filings blocking or can't meet the requirements of thread depth.

2. Assemble common tools

2. 1 measuring tools

Commonly used measuring tools mainly include vernier measuring tools and dial indicators. Vernier measuring tools mainly include vernier calipers. Vernier caliper can measure length, thickness, outer diameter, inner diameter, hole depth, center distance and so on. Vernier calipers are divided into 0.05mm and 0.02mm vernier calipers. Vernier caliper is an indispensable measuring tool, so we must pay attention to its accuracy, and remove the burr of the workpiece when measuring to avoid scratching the caliper.

2.2 assembly drawing

Assembly drawing is a reflection of the designer's intention in mechanical design and an important technical basis for mechanical design and manufacturing. Assembly drawing is to express the working principle of machine or parts, the assembly relationship between parts, the main structural shapes of parts, and the dimensions and technical requirements required for assembly, inspection and installation. Therefore, when assembling, you must know the performance dimensions, assembly dimensions, installation dimensions and overall dimensions in the drawings. Refer to the assembly drawing for the following steps:

A, look at the title bar first to get a general idea of the parts. Look at the title bar to know the name, material, quantity ratio, etc. In order to have a general understanding of the function of the parts. For unfamiliar and complicated assembly drawings, it is usually necessary to consult relevant technical data. For example, the assembly drawing of the parts where the parts are located, the relevant drawings of other parts and their technical specifications, etc. , so as to understand the function, structural characteristics and design requirements of parts in machines or components. Create conditions for looking at pictures;

B, deeply analyze the view and imagine the structural form;

C, analysis of technical requirements, a comprehensive understanding of the whole picture. This paper mainly analyzes the requirements of surface roughness, dimensional tolerance and shape and position tolerance of parts. First of all, it is necessary to understand the machining accuracy requirements of the mating surface or the main machining surface, understand the code meaning, then analyze the corresponding requirements of other machined surfaces and non-machined surfaces, understand the machining characteristics and functional requirements of parts, and then understand and analyze other technical requirements such as material heat treatment, surface treatment or modification, inspection and so on.

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