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Aircraft model parts processing

Aircraft model parts processing, toy parts gear machining, aircraft model hardware parts, aircraft model motor shell

What is the quality of the automated part processing machine?

The quality of the machine depends on the machining quality of the parts and the assembly quality of the machine. The machining quality of the parts includes the machining accuracy and the surface quality of the parts. The machining accuracy of the parts refers to the degree that the actual geometric parameters (size, shape and position) after machining are consistent with the ideal geometric parameters. The difference between them is called machining error. The machining error reflects the machining accuracy. The larger the error is, the lower the machining accuracy is, the smaller the error is, the higher the machining accuracy is; the main aspects affecting the machining accuracy are: dimensional accuracy, the degree of conformity between the actual dimension of the machined part and the tolerance zone center of the part dimension. Compared with the method of producing parts by die-casting die, it avoids the uneconomical of opening die when manufacturing small batch parts and greatly shortens the production cycle. At the same time, the correct clamping positioning and reasonable processing technology make the machined parts have high precision and surface finish, which is not achieved by the die casting technology. Moreover, the density of extruded aluminum profile is relatively high, and the strength of processed parts is higher than that of die casting. In addition, this method is different from the general single part machining production, it can produce a bed of parts in batch. If the worktable of the machine tool is large enough, the base plate can be larger, and several aluminum materials can be arranged at a time, the processing efficiency can be further improved, and the number of tool changes can be relatively reduced. If there are features on the side of the part to be machined, for example, if there are round holes to be drilled, then after the part is cut on the B side, the fixture shall be manufactured, and the part shall be installed before machining.

What is the effect of CNC rough machining on parts?

With the continuous development of the processing industry, what we use can only be completed after processing, and the processing must use machines to reduce product defects. Dongguan CNC parts processing is one of them, so what kind of consequences will be caused by rough CNC processing on parts?

1. Impact on wear resistance: the rougher the surface of CNC machining, the smaller the effective contact area between mating surfaces, the greater the pressure, the greater the friction resistance and the faster the wear.

2. Affect the stability of fit: for gap fit, the rougher the surface is, the easier it is to wear, so that the middle gap in the working process gradually increases; for interference fit, because the micro convex peak is squeezed flat during assembly, the practical effective interference is reduced, and the joint strength is reduced.

3. Influence on fatigue strength: there are large grooves on the surface of rough parts. Like sharp corner notches and cracks, they are sensitive to stress concentration, thus affecting the fatigue strength of parts.

4. Impact on corrosion resistance: the rough surface of parts is easy to make corrosive gas or liquid penetrate into the inner metal layer through the micro concave Valley on the surface, forming external corrosion.

5. Influence on sealing: rough surfaces cannot fit tightly, and gas or liquid leaks through the gap between contact surfaces.

6. Influence on contact stiffness: contact stiffness is the ability to resist contact deformation of the separation surface of the part under the action of external force. The stiffness of the machine depends on the contact stiffness between the parts to a great extent.

7. Affect the measurement accuracy: the surface roughness of the measured surface of the part and the measuring surface of the measuring tool will directly affect the measurement accuracy, which is in the fine measurement.

Which parts are suitable for precision machining?

We know that precision machining requires high precision. Precision machining has good rigidity, high manufacturing precision and accurate tool setting, so it can process parts with high precision. Which parts are suitable for precision machining? Here’s the introduction:

First of all, compared with the general lathe, CNC lathe has the function of constant linear speed cutting. No matter for the end face or the outer circle with different diameters, it can be processed with the same linear speed, which guarantees the surface roughness value and is relatively small. The general lathe is a constant speed, different diameter cutting speed is different. In the case of workpiece and tool material, finishing allowance and tool angle, surface roughness depends on cutting speed and feed speed.

When machining surfaces with different surface roughness, small feed speed is selected for surfaces with small roughness, and larger feed speed is selected for surfaces with large roughness, which has good variability, which is difficult to achieve in general lathe. Parts with complex contour. Any plane curve can be approximated by a straight line or an arc. CNC precision machining has the function of arc interpolation, which can process various parts with complex contour. The use of CNC precision machining needs the careful use of the operator.

CNC precision machining mainly includes finishing turning, boring, milling, grinding and other processes:

(1) Fine turning and fine boring: most of the precision light alloy (aluminum or magnesium alloy, etc.) parts of the aircraft are processed in this way. Generally, natural single crystal diamond cutting tools are used, and the arc radius of the cutting edge is less than 0.1 μ M. The surface roughness of 1 μ m and average height difference less than 0.2 μ M can be obtained by machining on high-precision lathe, and the coordinate accuracy can reach ± 2 μ M.

(2) Finish milling: used for machining aluminum or beryllium alloy structural parts with complex shape. Depending on the precision of machine tool’s guide rail and spindle, we can get high precision of mutual position. The precise mirror surface can be obtained by high-speed milling with a carefully ground diamond cutter head.

(3) Fine grinding: used for machining shaft or hole parts. Most of these parts are made of hardened steel with high hardness. Most high-precision grinding machine spindles adopt hydrostatic or hydrodynamic liquid bearings to ensure high stability. The grinding accuracy is not only affected by the rigidity of machine tool spindle and bed, but also related to the selection and balance of grinding wheel, the machining accuracy of workpiece center hole and other factors. The size accuracy of 1 μ m and the out of roundness of 0.5 μ M can be obtained by fine grinding.

(4) Grinding: select and process the irregular convex parts on the surface to be processed by the principle of mutual grinding of mating parts. Abrasive diameter, cutting force and cutting heat can be precisely controlled, so it is a high-precision machining method in precision machining technology. The hydraulic or pneumatic mating parts of the precise servo components of the aircraft and the bearing parts of the dynamic pressure gyro motor are processed by this method to achieve the accuracy of 0.1 or even 0.01 μ m and the micro unevenness of 0.005 μ M.

What should we pay attention to when processing precision hardware parts?

We have introduced the process flow of precision hardware parts to you before, so today’s chief engineer of hardware will share the following precautions for precision hardware parts processing:

1. Check whether the moving part is filled with lubricating oil before the operation of precision hardware parts processing machinery, then start and check whether the clutch and brake are normal, and run the machine tool for 1-3 minutes by air. It is forbidden to operate when the precision hardware parts processing machinery is in fault.

2. Keep correct posture at work, and have enough spirit to deal with the work. If you find physical discomfort, you should leave the post immediately and report to the leader. During the operation, the operator shall be concentrated, no chatting and cooperating with each other. The operator shall not operate in the state of fidgety and tired to avoid

In case of accident, ensure operation safety. Before entering the work position, all employees shall check whether their clothes meet the work requirements. It is not allowed to wear slippers, high-heeled shoes and clothes that affect safety. Those with long hair shall wear safety helmet.

3、 When the die is replaced, the power supply shall be turned off first, and the die can be installed and debugged only after the movement Department of the press stops running. After installation and adjustment, move the flywheel by hand twice for trial punching, and check whether the upper and lower dies are symmetrical and reasonable, whether the screws are firm, and whether the blank holder is in a reasonable position.

4. After other personnel leave the mechanical working area and take away the sundries on the workbench, the power supply can be started to start the machine.

5. When the precision hardware parts processing machinery works, it is forbidden to extend your hand into the sliding block working area, and it is forbidden to take and place the workpiece by hand. Use standard tools when taking and placing workpieces in the die. In case of abnormal sound or failure of the machine, turn off the power switch immediately for inspection.

After the machine is started, one person shall transport materials and operate the machine. Other people shall not press the electric building or step on the foot switch board, nor put the hand into the mechanical working area or touch the moving part of the machine by hand.

6. When leaving work, turn off the power supply and tidy up the finished products, leftovers and sundries on the post to ensure the working environment is clean and safe.

What should be paid attention to in CNC machining?

Nowadays, with the continuous improvement of science and technology, our industry needs to use a variety of processing, in the process of processing, we will inevitably have a variety of problems, or we need to comply with the problem, Dongguan CNC parts processing is one of them, so what should be paid attention to CNC parts processing?

1. Observe the operation regulations of machining center.

2. Before work, wear protective equipment and cuff as required. Scarf, gloves, tie and apron are not allowed. Women’s hair braid shall be tied in the hat.

3. Check whether the tool compensation, machine zero point, workpiece zero point, etc. are correct before starting the machine.

4. The relative position of each button shall meet the operation requirements. Carefully compile and input numerical control program.

5. Check the operation conditions of the protection, safety, signal, position, mechanical transmission part, electrical, hydraulic digital display and other systems on the equipment, and carry out cutting under all normal conditions.

6. Before the CNC parts are processed, the test run of the machine tool shall be carried out to check the operation conditions of the lubrication, mechanical, electrical, hydraulic, digital display and other systems, and the machining can be carried out under normal conditions.

7. After the machine tool enters the processing operation according to the program, the operator is not allowed to contact the moving workpiece, cutter and transmission part, and is not allowed to transfer or take tools and other items across the transmission part of the machine tool.

8. When adjusting the machine tool, clamping workpiece and cutter, and wiping the machine tool, stop the machine.

9. Tools or other articles shall not be placed on electrical appliances, operation cabinets and protective covers.

10. It is not allowed to remove iron chips directly by hand, and special tools shall be used for cleaning.

11. In case of abnormal condition and alarm signal, stop the vehicle and ask relevant personnel to check. CNC machining center.

12. It is not allowed to leave the work position when the machine tool is running. If you want to leave for some reason, put the workbench in the middle position, return the cutter bar, stop the machine, and cut off the power supply of the main machine.

What are the technical requirements in machining?

Machining is mainly precision machining, because precision machining can highlight the importance of machining products at work. Now machining is important for every project and technology. Now machining is getting better and better, and technology is also better. Now, there are more purchases of machining raw materials. With the development of society, we are With continuous development, many machining industries are expanding at a fast speed.

(1) Remove oxide skin from parts.

(2) There shall be no scratch, scratch and other defects on the machined surface of parts.

(3) The tolerance of undeclared shape shall meet the requirements of gb1184-80, and the allowable deviation of undeclared length dimension shall be ± 0.5mm.

(4) The tolerance zone of casting is symmetrical to the basic dimension configuration of rough casting.

(5) It is allowed to heat the assembled rolling bearing with engine oil, and the temperature of the oil shall not exceed 100 ℃.

(6) When assembling the hydraulic system, it is allowed to use sealing filler or sealant, but it shall be prevented from entering the system.

(7) The parts and components to be assembled can be assembled only after they have the certificate of inspection department.

(8) Parts must be cleaned and cleaned before assembly, without burr, flash, oxide skin, rust, chip, oil stain, colorant and dust, etc.

(9) Before assembly, the main fitting dimensions of parts and components, including interference fit dimensions and relevant accuracy, shall be rechecked.

(10) Parts shall not be knocked, bumped, scratched or rusted during assembly.

(11) When screws, bolts and nuts are tightened, it is strictly prohibited to strike or use improper screwdrivers and wrenches. After fastening, the screw slot, nut, screw and bolt head shall not be damaged.

(12) The fasteners with specified tightening torque shall be tightened with torque wrench according to the specified tightening torque.

(13) Excess adhesive shall be removed after bonding.

(14) The semicircle holes of the bearing outer ring, the open bearing seat and the bearing cover shall not be stuck; the semicircle holes of the bearing outer ring, the open bearing seat and the bearing cover shall be in good contact. During the color coating inspection, they shall be in uniform contact within the range of 120 ° symmetrical to the center line and 90 ° symmetrical to the center line.

(15) After the bearing outer ring is assembled, it shall be in even contact with the end face of the bearing cover at the locating end.

(16) After the rolling bearing is installed, it shall rotate flexibly and stably by hand.

(17) The joint surface of the upper and lower bearing shells shall be closely pasted and cannot be checked with a 0.05mm feeler gauge.

(18) When fixing the bearing bush with the locating pin, the reaming and pin distribution shall be conducted under the condition that the opening and closing surfaces and the end face of the bearing bush mouth and the end face are flush with the opening and closing surfaces of the relevant bearing holes and the end face package. The pin shall not be loose after driving.

(19) When the surface of the alloy bearing liner is yellow, it is not allowed to use it, and there is no phenomenon of nucleation within the specified contact angle. The area of nucleation outside the contact angle shall not be greater than 10% of the total area of the non-contact area.

(20) The reference end face of gear (worm gear) and the end face of shaft shoulder (or locating sleeve) shall fit, and the 0.05mm feeler gauge shall be used to check whether they can not enter. The perpendicularity of the gear reference end face and the axis shall be ensured.

General principles of precision parts processing

Today I would like to add the general principle of precision parts processing, that is, the general principle of precision parts processing process, which is mainly elaborated from the following four points:

1. Benchmark first

That is to say, the datum plane should be processed first. In the process of machining, the surface as the positioning datum should be processed first, so as to provide the precision datum for the subsequent processing as soon as possible.

2. Division of processing stages

The appearance with high machining quality request can be divided into three stages: rough machining, semi finish machining and finish machining. The main purpose is to ensure the processing quality; to facilitate the scientific application of equipment; to facilitate the arrangement of heat treatment process; and to facilitate the detection of blank defects.

3. Face before hole

For the box, bracket, connecting rod and other parts, the plane shall be machined before the hole is machined. In this way, the hole can be machined by plane positioning, ensuring the position accuracy of plane and hole, and bringing convenience to the machining of hole on plane.

4. Finishing

Finishing of main surfaces, such as grinding, honing, finishing, rolling, etc., shall be placed at the end of the process route. The general principle of drawing up the processing route of precision parts and the formulation of the processing procedure of precision parts can be roughly divided into two parts. First of all, it is to draw up the process route of parts processing, and then determine the process size of each process, used equipment and process equipment, cutting specifications, working hours quota, etc.

Processing requirements for precision parts

Mechanical parts processing industry is the pillar industry of the national economy, with a very considerable prospect. In the processing of precision mechanical parts, the processing factory will have many requirements and regulations on the processing technology to ensure the qualified rate of the parts. So do you know the requirements of precision machining technology? Let’s take a look at it!

1. Parts shall be free of oxide skin, scratches, scratches and other defects that may damage the surface of parts, and burr and flash shall be removed;

2. After quenching and tempering, the parts are quenched at high frequency, tempered at 350-370 ℃, hrc40-45, carburized at a depth of 0.3mm, and aged at high temperature.

3. The tolerance of undeclared shape shall meet the requirements of gb1184-80, the allowable deviation of undeclared length dimension shall be ± 0.5mm, and the tolerance zone of casting shall be symmetrical to the basic dimension configuration of rough casting;

4. The radius of undeclared fillet R5, undeclared chamfer are 2 × 45 °, sharp angle is blunt;

5. The temperature shall not exceed 100 ℃, after the gear is assembled, the contact spot and side clearance of the gear surface shall meet the provisions of GB10095 and gb11365;

6. When assembling the hydraulic system, it is allowed to use sealing filler or sealant, but it shall be prevented from entering into the system. The parts and components (including purchased parts and outsourced parts) that enter into the assembly must have the qualification certificate of the inspection department before assembling.

How to inspect precision machining parts?

Precision machine parts require precision. In the actual production process, we must reach the relevant standards for precision and try to improve it. At present, how to improve the precision of precision mechanical parts has become a key issue for related enterprises. The problems of deburring and polishing in the process of machining will directly affect the accuracy of parts, and it is also a difficult problem to solve in the current production automation. What I want to explain to you today is how to inspect precision machining parts?

One、 Basic requirements for inspectors:

1. To have professional knowledge and practical work experience, but also need to meet the requirements of the first product inspection work.

2. The measuring instruments used shall be verified by the measuring department and within the specified verification period.

3. Before product acceptance, it is necessary to be familiar with relevant drawings and technical documents, and understand the key dimensions of parts and key points of assembly.

4. The parts shall be determined in strict accordance with the requirements of drawings and technical documents.

5. Mark the products in process in the workshop according to the regulations.

Two、 Inspection system:

1. First inspection system: for the first part processed by each operator, it is necessary to conduct all-round inspection and keep it.

2. Inspection system: ensure that key parts will be able to obtain the whole process of controlled state.

3. Sequence transfer inspection system: for parts to be transferred to the next process, inspection shall be carried out to avoid unqualified products flowing into the next process.

4. Completion inspection system: the completion inspection shall be carried out for the products to be warehoused after the completion of production, including size and shape, whether there is missing processing procedure, etc.

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