CN103659205A - Minitype filter screen component preparing method for aircraft engine oil way system - Google Patents

Abstract

The invention provides a minitype filter screen component preparing method for an aircraft engine oil way system. A stretching forming-laser hole punching-vacuum brazing technology is used, the labor intensity of an operator can be lowered, the consistency of products is improved, during a testing or using process, a flow control test is carried out, if an inner-outer pressure difference value of the filtering screen component is too large or small, the pressure difference value can be amended with a laser fusion hole sealing or hole punching method by increasing or decreasing the number of holes, repairability is achieved, and finished product pass rate is improved.

Description

Preparation method of micro filter screen assembly for aircraft engine oil circuit system

technical field

The invention belongs to the technical field of filter screen preparation methods, and in particular relates to a preparation method of a micro filter screen assembly used in an aircraft engine oil circuit system.

Background technique

A certain type of restrictor is used in the oil circuit system of aircraft engines. Its composition mainly includes two micro-filter components, which are installed at the front and rear. It mainly plays the role of controlling the flow. It has the function of filtering impurities. The filter screen assembly is welded by the filter and the skeleton. It is small in size and complex in structure. The thickness of the filter is only 0.1mm, the minimum diameter of the mesh is 0.2mm, the minimum hole spacing is 0.1mm, the minimum inner diameter is 1.5mm, and the minimum outer diameter is 3.2mm. , the manufacturing process is extremely difficult. At present, foreign countries adopt the manufacturing process of "manual drilling mold punching-drawing forming-welding". This method has the following disadvantages: First, manual drilling mold drilling is labor-intensive, the mesh diameter and hole spacing are not easy to guarantee, and the product is consistent. The second is that the strength is greatly reduced after the dense mesh is formed by punching holes first, and it is easy to cause cracks in the process of forming wrinkles by stretching and forming, and the amount of scrap is large; the third is that in the process of forming wrinkles by stretching, as the material The deformation and the holes are also deformed, and some are even blocked, which reduces the effective filtration area; fourth, the process of punching holes first and then stretching is likely to cause stress concentration, and the service life and reliability are reduced; , the number of holes is fixed, the deformation of the holes is uncontrollable during stretch forming, and when the internal and external pressure difference does not meet the requirements, it cannot be repaired, only scrapped, and the qualified rate of finished products is extremely low. The above-mentioned defects are insurmountable bottlenecks in the process of preparing the micro-screen assembly, so it is necessary to improve them.

Contents of the invention

The technical problem solved by the present invention is to provide a method for preparing a micro-filter assembly used in an aircraft engine oil circuit system, which adopts the "stretch forming-laser drilling-vacuum brazing" process, which can reduce the labor intensity of the operator and improve the quality of the product. Consistency, economical and repairable, easy to realize the use function of the product, and improve product reliability.

The technical scheme adopted in the present invention: the method for preparing the micro filter screen assembly used in the aircraft engine oil circuit system comprises the following steps:

1) Stretch forming: Take the raw material of the filter and punch it into a disc with a certain diameter, then use a special mold to stretch the disc into a barrel shape with a certain diameter and height, and use a lathe to flatten the end face of the open end of the barrel-shaped filter and deburr it , and then change another set of special molds to stretch out multiple folds from the open end of the barrel-shaped filter along its axis to form a shaped filter;

2) Laser drilling: Put the barrel-shaped filter on the special fixture and use a laser to punch a number of small holes on the hemispherical surface of the sealing end, then remove it, and then install the formed filter on the fixture with indexing function. The same small holes are also punched on the circumferential surface of the filter disc;

3) Vacuum brazing: punch a silver-copper brazing material sheet with a thickness of 0.2mm into a ring piece with an inner and outer diameter slightly smaller than the skeleton; then clean the skeleton, formed filter and ring piece with gasoline or ethanol; clean the skeleton, The ring piece and the formed filter piece are installed on the graphite fixture from bottom to top, so that one side of the ring piece is close to the side wall of the skeleton, and the opening end of the formed filter piece is close to the other side of the ring piece, and placed in the tool box into the vacuum brazing furnace , evacuate to (1-3)*10 ^-1 Pa, raise the temperature to 850 ℃ ~ 900 ℃ with the furnace, keep it warm for 5 to 10 minutes, cool it out of the furnace with the furnace, and check the quality of the weld.

In the process of use, the flow control test is carried out. When the pressure difference between the inside and outside of the filter screen assembly does not meet the requirements, laser melting is used to seal or punch holes, and the number of holes is increased or decreased to correct the pressure difference.

In the above step 1), the number of the wrinkles is 3-20.

Further, the shape of the formed filter piece is a round barrel or a square barrel.

Advantage of the present invention compared with prior art:

1. The present invention adopts the process of "stretch forming-laser drilling-vacuum brazing", which solves the shortcomings of the existing process methods, improves the manufacturing efficiency and reliability of products, and has great application value;

2. The new technology of laser drilling is adopted, which greatly reduces the labor intensity, and the mesh diameter, hole spacing, and hole roundness are easy to guarantee, and the consistency is good;

3. Adopting the process of stretching and forming first, then punching, it is not easy to cause cracking and scrapping during the process of forming wrinkles, and it is not easy to cause stress concentration, which improves product reliability;

4. Stretching and forming first, and then drilling, the holes will not be deformed, ensuring the effective filtering area of the filter;

5. During the test or use, if the pressure difference between the inside and outside of the filter screen assembly is too large or too small, the method of laser melting sealing or drilling can be used to increase or decrease the number of holes, making it reworkable and improving the quality of the finished product. Pass rate.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is a left side view of Fig. 1 .

Detailed ways

An embodiment of the present invention is described below in conjunction with accompanying drawings 1-2.

A method for preparing a miniature filter screen assembly for an aircraft engine oil circuit system, comprising the following steps:

1) Stretch forming: Take the raw material of the filter and punch it into a disc with a certain diameter, and then use a special mold to stretch the disc into a barrel shape with a certain diameter and height. Burrs, and then another set of special molds are used to stretch out a plurality of folds 5 from the open end of the barrel-shaped filter along its axis to form a shaped filter 3; the number of folds 5 is 3 to 20;

2) Laser drilling: Put the barrel-shaped filter 3 on the special fixture and use a laser to punch a number of small holes 4 on the hemispherical surface of the sealing end, then remove it, and then install the formed filter 3 on the fixture with indexing function , the same small hole 4 is also punched on the circumferential surface of the formed filter 3; the process of stretching and forming first and then punching is adopted, and it is not easy to cause cracking and scrapping during the formation of wrinkles, and it is not easy to cause stress concentration, which improves product reliability. , and the small holes 4 will not be deformed, which ensures the effective filtering area of the filter screen; the use of laser drilling greatly reduces the labor intensity, and the diameter, hole spacing, and roundness of the holes are easy to guarantee, and the consistency is good;

3) Vacuum brazing: Punch a silver-copper brazing material sheet with a thickness of 0.2mm into a ring piece 2 with an inner and outer diameter slightly smaller than the skeleton 1; then clean the skeleton 1, formed filter piece 3 and ring piece 2 with gasoline or ethanol Clean; install the frame 1, ring piece 2, and shaped filter piece 3 on the graphite fixture from bottom to top, so that one side of the ring piece 2 is close to the side wall of the frame 1, and the opening end of the shaped filter piece 3 is close to the ring piece 2. On one side, put it in a tool box and put it into a vacuum brazing furnace, evacuate to (1-3)*10 ^-1 Pa, heat up to 850°C-900°C with the furnace, keep it warm for 5-10 minutes, cool it out of the furnace with the furnace, and check Weld quality. During the test or use, if the flow control test is carried out, if the pressure difference between the inside and outside of the filter screen assembly is too large or too small, laser melting can be used to seal or punch holes, and the number of holes can be increased or decreased by using laser melting to seal or punch holes , to correct the pressure difference to make it reworkable and improve the qualified rate of finished products.

The foregoing embodiments are only preferred embodiments of the present invention, and are not intended to limit the scope of the present invention, so all equivalent changes made with the contents of the claims of the present invention should be included within the scope of the claims of the present invention .

Claims (4)

1. for the miniature filter screen assembly preparation method of aircraft engine oil piping system, it is characterized in that comprising the steps:

1) drawing and forming: get the disk that filter disc raw material strike out certain diameter, with particular manufacturing craft, disk is drawn into again to the tubbiness of certain diameter and height, end face with the flat tubbiness filter disc of lathe openend, and deburring, then change another set of particular manufacturing craft and from tubbiness filter disc openend along the stretched a plurality of wrinkle of its axis (5), form moulding filter disc (3);

2) laser boring: tubbiness moulding filter disc (3) is loaded onto after special fixture is got a plurality of apertures (4) with laser on the hemisphere face of its sealing end and taken off, again moulding filter disc (3) is loaded onto to the fixture with calibration function, on the periphery of moulding filter disc (3), also get same aperture (4);

3) vacuum brazing: the ag-cu solder sheet that is 0.2mm by thickness strikes out the circular ring plate (2) that internal-and external diameter is slightly smaller than skeleton (1); With gasoline or ethanol, skeleton (1), moulding filter disc (3) and circular ring plate (2) are cleaned up again; Skeleton (1), circular ring plate (2), moulding filter disc (3) are contained on graphite fixture from the bottom to top, make circular ring plate (2) one side be adjacent to skeleton (1) side wall surface, moulding filter disc (3) openend is adjacent to circular ring plate (2) another side, be placed in instrument cases and enter vacuum brazing furnace, be evacuated to (1-3) * 10 ^-1pa, is warmed up to 850 ℃～900 ℃ with stove, is incubated 5～10 minutes, comes out of the stove, and check weldquality with stove is cooling.

2. the miniature filter screen assembly preparation method for aircraft engine oil piping system according to claim 1, it is characterized in that: in use, control flow test, when net-filter assembly external and internal pressure difference does not reach while requiring, the quantity that adopts laser fusion sealing of hole or punching, increase and decrease hole, revises pressure difference value.

3. the miniature filter screen assembly preparation method for aircraft engine oil piping system according to claim 1 and 2, is characterized in that: above-mentioned steps 1), the quantity of described wrinkle (5) is 3～20.

4. the miniature filter screen assembly preparation method for aircraft engine oil piping system according to claim 3, is characterized in that: described moulding filter disc (3) be shaped as circular tubbiness, oval tubbiness or square tubbiness.

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