Method for precision compound machining and forming of aero-engine l-shaped cross-section ring

Abstract

The application discloses a precision composite machining forming method for an L-shaped section ring of an aero-engine, which comprises the following steps: forging ring blank design: reasonably designing a rolling ring blank according to the deformation mechanism of rolling forming metal of the L-shaped section ring and the filling characteristics of the section profile; ring forging rolling forming: adopting a radial rolling forming process, the height of the ring forging is basically unchanged during the rolling process, the diameter is gradually increased, and the section profile is gradually formed; precision machining forming: performing turning and milling processing on the rolling ring forging, the surface roughness and quality of the ring are further improved by reasonably controlling the processing parameters, and finally the target part with high performance is obtained. The forging ring blank of the ring can be accurately designed, the ring can be processed and formed with high performance, the overall mechanical performance of the ring is improved, and only a small amount of cutting processing is required for the forging, so that the utilization rate of the ring machining material and the production efficiency are greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine manufacturing technology, specifically a forming and processing method for an L-shaped cross-section ring component for aero-engines. Background Technology

[0002] L-shaped cross-section rings are critical aero-engine components with wide applications, such as high-pressure spacer rings and retaining rings. Typically, these rings have an L-shaped cross-section, a smooth, straight inner surface, and an outer stepped surface. Ventilation holes and mounting holes are distributed circumferentially around the ring. Furthermore, these rings have a relatively small height-to-diameter ratio, with diameters generally ranging from 500mm to 1000mm and heights from 20mm to 50mm, placing extremely high demands on their machining quality and mechanical properties.

[0003] Currently, the manufacturing of L-shaped cross-section rings mainly involves forging the ring to obtain a rectangular cross-section ring that meets the requirements, followed by machining to gradually shape the L-shaped cross-section profile. Clearly, directly machining the rectangular cross-section ring results in large-area cutting, leading to low material utilization, prolonged machining time, and reduced production efficiency. Furthermore, extensive cutting disrupts the integrity of the internal metal flow lines, reducing the ring's service life.

[0004] Therefore, there is an urgent need to develop a precision composite machining and forming method for aerospace L-shaped cross-section rings to achieve high-performance, high-quality, high-efficiency, and low-material-consumption manufacturing of such rings. Summary of the Invention

[0005] This invention aims to provide a precision composite machining and forming method for L-shaped cross-section ring parts for aero-engines, achieving high-performance precision machining and forming of L-shaped cross-section ring parts. This method can effectively improve the forging and filling accuracy of the ring part's cross-sectional contour, thus requiring only a small amount of cutting during the machining process, greatly improving the utilization rate of the ring part's manufacturing materials. Furthermore, the small amount of cutting essentially preserves the original mechanical properties of the ring part, improving its overall performance and extending its service life.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for precision composite machining and forming of L-shaped cross-section ring parts for aero-engines includes the following steps performed sequentially:

[0008] S1, forged ring billet design;

[0009] S11, Select a rectangular cross-section forged ring blank as the subsequent rolling blank. Combine the dimensions in the L-shaped cross-section ring part design drawing, and obtain the dimensions of the L-shaped cross-section ring part (hereinafter referred to as B, B) by adding machining allowance.b D s D b d and D s All dimensions are L-shaped cross-section ring parts with machining allowances added. The dimensions of the rectangular cross-section forged ring blank are calculated as follows:

[0010] The height B0 of the rectangular cross-section forged ring blank: B0 = B;

[0011] The inner diameter d0 of the rectangular cross-section forged ring blank: d0 = (1.2~1.5)d c ;

[0012] The volume V0 of the rectangular cross-section forged ring blank:

[0013] Outer diameter D0 of rectangular cross-section forged ring blank:

[0014] Where B is the total height of the L-shaped cross-section ring, and d c B is the diameter of the mandrel in the forging equipment. b It is the height of the large ring area of ​​the L-shaped cross-section ring component, D. s It is the outer diameter of the small ring of the L-shaped cross-section ring, D. b d is the outer diameter of the large ring of the L-shaped cross-section ring, and d is the inner diameter of the L-shaped cross-section ring.

[0015] S12, calculate the large ring wall thickness H of the L-shaped cross-section ring member according to the following method. b And the forming limit value H of the large ring wall thickness of the L-shaped cross-section ring. b-max :

[0016]

[0017] H b-max =λH s +(1-λ)H0;

[0018] in,

[0019] H s It is the thickness of the small ring region of the L-shaped cross-section ring component, and

[0020] λ is the rolling deformation coefficient of the L-shaped cross-section ring per revolution, and λ is calculated according to the following formula.

[0021]

[0022] H0 is the thickness of the rectangular cross-section forged ring blank, and

[0023] B s It is the height of the small ring of the L-shaped cross-section ring component, and Bs =BB b ;

[0024] S13, Compare the large ring wall thickness H of the L-shaped cross-section ring. b And the forming limit value H of the large ring wall thickness of the L-shaped cross-section ring. b-max ;

[0025] If H b ≤H b-max Then, jump to S3 and directly use the rectangular cross-section forged ring billet in S11 as the rolling billet for rolling:

[0026] If H b >H b-max If so, then jump to S2;

[0027] S2, modify the rectangular cross-section forged ring blank to obtain an optimized L-shaped cross-section forged ring blank:

[0028] S21, calculate the radius R of the large ring region of the L-shaped cross-section ring member according to the following methods. b And the limiting radius R of the large ring region of the L-shaped cross-section ring component. b-max ;

[0029]

[0030]

[0031] S22, calculate the volume ΔV for correction of rectangular cross-section forging ring billet using the following formula:

[0032] ΔV=πB b (R b 2 -R b-max 2 );

[0033] Assuming the volume V0 and inner diameter d0 of the rectangular cross-section forged ring blank remain constant, the height B of the small ring of the L-shaped cross-section ring is... s Height B of the large ring area of ​​the L-shaped cross-section ring component b The rectangular cross-section forged ring blank is divided into an upper region and a lower region along the axial direction. A height of B is removed from the outer ring of the upper region in the form of a rectangular cross-section ring structure. s Let the volume be V1, and denote V1 = ΔV. Then, let ΔV be expressed with height B. b A rectangular cross-section ring structure is added to the outer ring of the lower region as a compensating volume V2, thereby obtaining a modified L-shaped cross-section forged ring blank.

[0034] S23, calculate the corrected outer diameters of the small and large rings of the L-shaped cross-section forged ring blank using V1 and V2. Replace the outer diameter D0 of the rectangular cross-section forged ring blank with the corrected outer diameter of the large ring of the L-shaped cross-section forged ring blank, and then use the calculation method in S12 to obtain the wall thickness H of the large ring of the L-shaped cross-section ring. b And the forming limit value H of the large ring wall thickness of the L-shaped cross-section ring. b-max Then determine H b and H b-max The relationship, if H b ≤H b-max Then jump to S3, if H b >H b-max If the L-section forging ring blank is corrected again, a new L-section forging ring blank will be obtained.

[0035] S3, rolling forming of ring forgings: For the rectangular cross-section forged ring blank in S11 or the L-shaped cross-section forged ring blank obtained in S23, radial rolling forming is used to obtain the size of the L-shaped cross-section ring with machining allowance;

[0036] S4, the ring forging is turned into shape, and the axial end face, inner hole and outer circular surface of the L-shaped cross section ring obtained in S3 are machined to obtain the final dimensions in the part design drawing;

[0037] S5, the ring forging is milled to form the circumferentially distributed holes in the large ring area of ​​the L-shaped cross-section ring to obtain the final dimensions in the part design drawing.

[0038] Alternatively, in S3, the radial rolling forming device includes a drive roller, a tapered roller, and a core roller. The drive roller rotates actively and contacts the outer ring surface of the rolled ring blank. The core roller makes a radial feed motion and contacts the inner ring surface of the rolled ring blank. The tapered roller presses against the two axial end faces of the rolled ring blank.

[0039] Alternatively, the radial rolling forming includes an initial rolling biting stage and a stabilizing rolling diameter expansion stage, wherein in the initial rolling stage, the feed speed v1 = (0.2~0.8)v, and in the diameter expansion stage, the feed speed v2 = (1~1.2)v, where v is the core roll feed speed.

[0040] Alternatively, the core roller feed speed v is calculated using the following formula:

[0041] Among them, v max It is the maximum feed speed of the mandrel during the rolling process of L-shaped cross-section rings, v min It is the minimum feed speed of the mandrel during the rolling process of L-shaped cross-section ring parts.

[0042] Alternatively, in S4, the two axial end faces of the L-shaped cross-section ring are first machined to obtain the machining datum. Then, the inner hole of the L-shaped cross-section ring is machined using the two axial end faces as the datum to obtain the inner hole diameter. Finally, the L-shaped outer circle of the L-shaped cross-section ring is machined to obtain the designed machining dimensions.

[0043] Alternatively, during the turning process, the cutting feed rate v q Calculate using the following formula:

[0044] Among them, D q is the outer diameter of the ring forging being machined, and n is the spindle speed of the turning equipment.

[0045] Alternatively, when the two axial end faces of the L-shaped cross-section ring are machined, the spindle speed n is controlled between 25 and 35 r / min.

[0046] Alternatively, the two axial end faces, the inner hole, and the L-shaped outer circle are all formed by turning in one step to remove machining allowance.

[0047] Alternatively, in step S5, a milling cutter is first used to mill out the circumferentially distributed holes of the L-shaped cross-section ring, and then a chamfering cutter is used to remove the burrs on the edges of the circumferentially distributed holes and chamfer them.

[0048] Alternatively, in S5, the first step is to rough mill the circumferentially distributed holes, and the second step is to finish mill and enlarge the holes.

[0049] Compared with the prior art, the processing method of the present invention has the following characteristics:

[0050] (1) Based on the deformation characteristics of the ring rolling forming process, a design method for forging ring blanks for L-shaped cross section ring rolling process is given.

[0051] (2) Based on the principle of constant volume during the ring forging and rolling process, an optimized design scheme for superimposed correction of the ring blank is proposed when the cross-sectional profile of the L-shaped cross-section ring cannot be accurately filled during the design process of the ring blank. This further ensures that the ring can be accurately formed during the rolling process, laying the foundation for subsequent high-efficiency, high-quality and low-material precision machining.

[0052] (3) The final geometric dimensions of the target part are obtained by precision machining methods such as turning and milling. Compared with traditional machining, this machining requires only a small amount of cutting, which ensures the integrity of the metal flow lines in the internal structure of the ring and guarantees the mechanical performance of the ring. In addition, the small amount of cutting also improves the machining efficiency of the ring and reduces the machining energy consumption; at the same time, it also improves the material utilization rate.

[0053] This invention can design forged ring blanks that are precision rolled, which greatly reduces the machining allowance in the machining process of the ring, shortens the machining cycle of the ring, and improves the mechanical properties and machining efficiency of the ring overall. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of the L-shaped cross-section ring component for an aero-engine in this invention;

[0055] Figure 2 This invention describes the precision composite machining and forming process of the L-shaped cross-section ring component for aero-engines.

[0056] Figure 3 This is a schematic diagram illustrating the optimized design of the forged ring blank for the L-shaped cross-section ring component of an aero-engine in this invention.

[0057] Figure 4 This is a flowchart illustrating the design process of the forging ring blank for the L-shaped cross-section ring of an aero-engine in this invention.

[0058] Figure 5 This is a schematic diagram of the initial rolling time of the L-shaped cross-section ring for aero-engines in this invention;

[0059] Figure 6 This is a schematic diagram showing the final rolling time of the L-shaped cross-section ring for aero-engines in this invention;

[0060] Figure 7 This is a schematic diagram of the allowance distribution of the rolled forging of the L-shaped cross-section ring component for aero-engines in this invention;

[0061] Figure 8 This is a schematic diagram of the machining process of the left and right end faces of the L-shaped cross-section ring of the aero-engine in this invention;

[0062] Figure 9 This is a schematic diagram of the machining process of the inner hole of the L-shaped cross-section ring of an aero-engine in this invention;

[0063] Figure 10 This is a schematic diagram of the external turning process of the L-shaped cross-section ring of the aero-engine in this invention to form a circle;

[0064] Figure 11 This is a schematic diagram of the milling and forming of the L-shaped cross-section ring hole of the aero-engine in this invention;

[0065] In the diagram, 1-drive roller, 2-conical roller, 3-core roller. Detailed Implementation

[0066] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, it should not be construed that the scope of the subject matter of the present invention is limited to the following embodiments. All modifications, substitutions and alterations made based on ordinary technical knowledge and common practices in the art without departing from the above-described technical concept of the present invention are included within the scope of the present invention.

[0067] by Figure 1 The L-shaped cross-section ring component of the aero-engine shown (part B in the part drawing) f B bf D sf D bf d f D sf and D kf Taking the final dimension of an L-shaped cross-section ring after removing machining allowances as the object, the main steps of its forming process include:

[0068] 1. Forging ring billet design:

[0069] The first step involves machining the forged ring blank using a radial rolling forming process. Based on the preliminary design of the L-shaped cross-section ring, a rectangular cross-section forged ring blank is used as the rolling ring blank. The wall thickness of the L-shaped cross-section ring is determined, and the volumes of the large and small ring regions within the L-shaped cross-section ring are calculated. The ratio of the small ring wall thickness to the large ring wall thickness (H) is calculated based on the L-shaped cross-section ring. s / H b ), the ratio of the height of the small ring to the total height (B) s / B) and the target wall thickness of the large ring (H) b ); Calculate the forming limit value (H) of the large ring wall thickness of the L-shaped cross-section ring based on the rolling deformation behavior. b-max ).

[0070] The second step is to determine whether the target wall thickness of the large ring of the L-shaped cross-section ring is less than or equal to its rolling forming limit value (H). b ≤H b-max If the condition is met, directly output the dimensions of the rectangular cross-section forged ring blank; otherwise, the dimensions of the rectangular cross-section forged ring blank need to be corrected. During the correction process, if... Figure 4 As shown, first calculate the volume V1, then subtract V1 from the outer part of the upper region of the rectangular cross-section forged ring blank (corresponding to the height region of the small ring of the L-shaped cross-section ring), so that it increases to form volume V2 on the outer part of the lower region of the rectangular forged ring blank (corresponding to the height region of the large ring of the L-shaped cross-section ring). The total volume of the obtained L-shaped cross-section ring blank remains unchanged (i.e., Figure 4 (The initial ring blank volume on the left is equal to the final ring blank volume on the right), thus obtaining a new L-shaped cross-section ring blank size and shape, as shown below. Figure 4 As shown.

[0071] The third step involves re-determining the wall thickness of the corrected L-shaped cross-section ring blank, calculating the volumes of the large and small rings, and obtaining the outer diameter dimensions of the L-shaped cross-section ring blank (including the outer diameter D of the large ring). b0 and the outer diameter D of the small ring s0 ), calculate the H of the corrected L-shaped cross-section ring blank. b-max The value is then used to determine whether the target value of the large ring wall thickness of the L-shaped cross-section ring is less than or equal to the rolling forming limit value (H) of its wall thickness. b ≤H b-max Similarly, through continuous superposition calculations, when the target wall thickness of the large ring of the L-shaped cross-section ring is less than or equal to its forming limit value (H)... b ≤H b-max When the desired rolled ring shape is obtained, the process is as follows: Figure 3 As shown.

[0072] In the first step above, the volume V0 of the rectangular cross-section forged ring billet is calculated using the following formula:

[0073]

[0074] Among them, D b d is the outer diameter of the large ring of the L-shaped cross-section ring, and d is the inner diameter of the L-shaped cross-section ring. s B is the outer diameter of the small ring of the L-shaped cross-section ring, and B is the total height of the L-shaped cross-section ring. s It is the height of the small ring of the L-shaped cross-section ring component.

[0075] In the first step above, the height of the rectangular cross-section forged ring billet is calculated using the following formula:

[0076] B0 = B;

[0077] In the first step above, the inner diameter of the rectangular cross-section forged ring blank is calculated using the following formula:

[0078] d0 = (1.2 ~ 1.5)d c ;

[0079] Where, d c It is the diameter of the core roller in the forging equipment.

[0080] In the first step above, the outer diameter of the rectangular cross-section forged ring blank is calculated using the following formula:

[0081]

[0082] In the first step above, the wall thickness value (H) of the large ring of the L-shaped cross-section ring component... b Calculate using the following formula:

[0083]

[0084] Among them, Db d is the outer diameter of the large ring of the L-shaped cross-section ring, and d is the inner diameter of the L-shaped cross-section ring.

[0085] In the first step above, the ratio of the wall thickness of the small ring to the wall thickness of the large ring in the L-shaped cross-section ring (H) s / H b It can be calculated using the following formula:

[0086]

[0087] Among them, D s It is the outer diameter of the small ring of the L-shaped cross-section ring component.

[0088] In the first step above, the forming limit value (H) of the large ring wall thickness of the L-shaped cross-section ring is... b-max Calculate using the following formula:

[0089] H b-max =λH s +(1-λ)H0;

[0090] Among them, H s H0 is the thickness of the small ring region of the L-shaped cross-section ring, and H0 is the thickness of the rectangular cross-section forged ring blank or the thickness of the large ring of the L-shaped cross-section forged ring blank. λ is the rolling deformation coefficient of the L-shaped cross-section ring per revolution, and λ is calculated according to the following test:

[0091]

[0092] Where H0 is the thickness of the rectangular cross-section forged ring blank, and B s It is the height of the small ring of the L-shaped cross-section ring component, and B s =BB b H s It is the thickness of the small ring region of the L-shaped cross-section ring component, and

[0093] In the second step above, when the rectangular cross-section forged ring blank is modified to an L-shaped cross-section forged ring blank, V1 = V2 is always maintained, and:

[0094] V1 = V2 = ΔV = πB b (R b 2 -R b-max 2 );

[0095]

[0096]

[0097] Among them, B bIt is the height of the large ring area of ​​the L-shaped cross-section ring component, R. b R is the radius of the large ring region of the L-shaped cross-section ring component. b-max d is the limiting radius of the large ring region of the L-shaped cross-section ring, and d is the inner diameter of the L-shaped cross-section ring.

[0098] In the second step above, since the inner diameter and height of the ring blank remain basically unchanged before and after the correction (i.e., the inner diameter and height of the rectangular cross-section forged ring blank are equal to the inner diameter and height of the L-shaped cross-section forged ring blank, while the height B of the small ring of the L-shaped cross-section ring part is different), s Height B of the large ring area of ​​the L-shaped cross-section ring component b It is known that, i.e. Figure 4 China B b0 =B b B s0 =BB b0 Therefore, based on the volumes of the large and small ring regions of the corrected L-shaped cross-section forged ring blank, the outer diameter of the large ring of the corrected L-shaped cross-section forged ring blank can be calculated separately. Figure 4 D in b0 ) and outer diameter of the small ring ( Figure 4 D in s0 This allows us to obtain the external dimensions of the L-shaped cross-section forged ring blank.

[0099] 2. Ring forging rolling forming:

[0100] The L-shaped cross-section ring is formed using a radial rolling process, which involves either a rectangular cross-section forged ring blank from the first step or an L-shaped cross-section forged ring blank designed in the third step (e.g., ...). Figure 5 As shown, radial rolling is used to form the L-shaped cross-section profile of the ring forging, gradually shaping the inner and outer diameters until the dimensions of the L-shaped cross-section ring before machining (including machining allowances B and B) are obtained. b D s D b d and D s ),like Figure 6 As shown. In addition, the radial rolling forming device includes a drive roller 1, a tapered roller 2 and a core roller 3. The drive roller 1 rotates actively and contacts the outer ring surface of the rolled ring blank; the core roller 3 makes radial feed motion and contacts the inner ring surface of the rolled ring blank; the tapered roller 2 presses against the two axial end faces of the rolled ring blank.

[0101] During the rolling process of a ring billet (rectangular cross-section forged ring billet or L-shaped cross-section forged ring billet), the mandrel feed speed v can be calculated using the following formula:

[0102]

[0103] Among them, v max It is the maximum feed speed of the mandrel during the rolling process of L-shaped cross-section rings, vmin It is the minimum feed speed of the mandrel during the rolling process of L-shaped cross-section ring parts.

[0104] The ring rolling process is mainly divided into two stages: the initial rolling biting stage and the stabilizing rolling diameter expansion stage. In the initial rolling stage, the mandrel feed speed is v1 = (0.2~0.8)v, and in the diameter expansion stage, v2 = (1~1.2)v.

[0105] 3. Precision machining of ring forgings:

[0106] Precision machining is achieved by combining turning and milling.

[0107] The first step is to process the rolled ring forging (such as...) Figure 7 As shown, to complete the radially rolled L-shaped cross-section ring forging with machining allowance (the double lines on the contour edge represent the machining allowance), each outer surface is machined separately to further improve the surface roughness and quality of the ring forging, making it meet the assembly and use requirements of the part. During the machining process, firstly, the left and right end faces of the ring forging are machined (e.g., ...). Figure 8 The left and right sides shown are the two axial end faces of the ring forging. The thick black lines in the left image change to thin black lines in the right image, and the dimension changes from B. b Become B bl B becomes B f Obtain the corresponding machining datum; then, using the two end faces as datum, machine the inner hole of the ring forging, such as... Figure 9 As shown (the thick black line in the left image changes to a thin black line in the right image, and the size changes from d to d), f This process is repeated to obtain the corresponding inner diameter; finally, the L-shaped outer circle of the ring forging is machined, such as... Figure 10 As shown, the final machining dimensions that meet the requirements are obtained (the outer diameter is determined by D). b and D s Change to D bf and D sf ).

[0108] In the above scheme, the cutting feed rate v during turning is... q Calculate using the following formula:

[0109]

[0110] Among them, D q is the outer diameter of the ring forging being machined, and n is the spindle speed of the turning equipment.

[0111] In the above scheme, when machining the left and right end faces of the ring forging, in order to prevent deformation and the appearance of tool marks on the machined surface, the spindle speed n is controlled between 25 and 35 r / min.

[0112] In the above scheme, when machining the surface of the ring forging, all surface allowances are removed in one machining operation.

[0113] The second step involves milling the L-shaped cross-section ring obtained in the first step to obtain circumferentially distributed holes (V) at the large ring of the ring. x n is the milling feed rate. x (This refers to the milling cutter speed), such as Figure 11 As shown, this process ensures the part meets usage requirements. During milling, a milling cutter is first used to mill the circumferentially distributed holes of the L-shaped cross-section ring. Then, a chamfering cutter is used to remove burrs from the edges of the circumferentially distributed holes and chamfer them, ultimately obtaining the target part.

[0114] In the above scheme, when machining the large circumferentially distributed holes of the ring forging, a two-step plan is adopted: the first step is to rough mill the circumferentially distributed holes, and the second step is to finish mill and enlarge the holes.

[0115] In the above scheme, when chamfering the circumferentially distributed holes of the ring forging, the tool diameter... The cross-sectional area is tooled to ensure that the chamfer meets the dimensional requirements.

[0116] Example 1:

[0117] The following is based on Figure 1 Taking the L-shaped cross-section ring of an aero-engine as an example, this invention further illustrates the precision composite machining and forming method for the aero-engine L-shaped cross-section ring.

[0118] The part drawing dimensions for the L-shaped cross-section ring are: d f =817mm, D sf =855mm, D bf =877mm, B f =42mm, B bf =20mm, D kf =10mm. The specific steps of the L-shaped cross-section ring forming method are as follows:

[0119] 1. Forging ring billet design:

[0120] The first step involves radial rolling forming of the ring forging, increasing the machining allowance. The dimensions of the rolled ring blank for the L-shaped cross-section ring are: d = 816 mm, D... s =856mm, D b =878mm, B=43mm, B b =21mm. Based on the dimensions of the L-shaped cross-section ring, a rectangular cross-section forged ring blank is initially designed as the rolled ring blank. The initial dimensions of the rolled ring blank are: D0 = 520, d0 = 430mm, B0 = 43mm. Figure 4 As shown. The ratio H of the small ring wall thickness to the large ring wall thickness is calculated based on the L-shaped cross-section ring.s / H b =0.65, the ratio of the height of the small ring to the total height B s / B = 0.49 and the target wall thickness H of the large ring b =31mm, L-shaped cross-section ring, rolling deformation coefficient λ = 0.49 per revolution, forming limit value H of the large ring wall thickness. b-max =32.75mm.

[0121] The second step is that the target wall thickness of the large ring of the L-shaped cross-section ring is less than or equal to the rolling forming limit value H of its wall thickness. b =31mm≤H b-max =32.75mm is established, directly output the dimensions of the rectangular cross-section forged ring billet, such as Figure 3 and Figure 4 As shown.

[0122] 2. Ring forging rolling forming:

[0123] The rectangular cross-section forged ring blank is formed by radial rolling, such as... Figure 5 As shown, by radially rolling the rectangular cross-section forged ring blank designed in the first step, the L-shaped cross-section profile of the ring blank is gradually formed, and the inner and outer diameters gradually expand until an L-shaped cross-section ring with machining allowance is obtained, with dimensions of d = 816 mm and D = 816 mm. s =856mm, D b =878mm, B=43mm, B b =21mm, such as Figure 6 As shown. Furthermore, the radial rolling forming apparatus includes a drive roll 1, a tapered roll 2, and a mandrel 3. The drive roll 1 rotates actively and contacts the outer ring surface of the rolled ring blank; the mandrel 3 performs a radial feed motion and contacts the inner ring surface of the rolled ring blank; the tapered roll 2 presses against the two axial end faces of the rolled ring blank. During the rolling process, the mandrel feed speed is 0.8 mm / s in the initial rolling stage and 1.5 mm / s in the diameter expansion stage.

[0124] 3. Precision machining of ring forgings:

[0125] Precision machining is achieved by combining turning and milling.

[0126] The first step is to process the rolled ring forgings (whose dimensions are: d = 816 mm, D...). s =856mm, D b =878mm, B=43mm, B b =21mm, B s =BB b =22mm) respectively turn its outer surfaces, such as Figure 7As shown, further improvements are made to the surface roughness and quality of the ring forging to ensure it meets the assembly and usage requirements of the part. During the turning process, the tool feed rate is 0.12 mm / s, and the spindle speed is 32 r / min. The left and right end faces of the ring forging are machined first to obtain the corresponding machining datum. The machining allowance for each end face is 0.5 mm. Figure 8 As shown; next, the inner hole of the ring forging is machined using both end faces as a reference, with a machining allowance of 0.5mm, as shown. Figure 9 As shown, the corresponding inner diameter is obtained; finally, the L-shaped outer circle of the ring forging is machined with a machining allowance of 0.5mm, as shown. Figure 10 As shown, the final processing dimensions that meet the requirements are: d f =817mm, D sf =855mm, D bf =877mm, B f =42mm, B bf =20mm.

[0127] The second step involves milling the L-shaped cross-section ring obtained in the first step to create circumferentially distributed holes with a diameter of D. kf =10mm, such as Figure 11 As shown, this process ensures the part meets usage requirements. During milling, a milling cutter is first used to mill the circumferentially distributed holes of the L-shaped cross-section ring. Then, a chamfering cutter is used to remove burrs from the edges of the circumferentially distributed holes and chamfer them, ultimately obtaining the target part with the following dimensions: d f =817mm, D sf =855mm, D bf =877mm, B f =42mm, B bf =20mm, D kf =10mm.

[0128] Contents not described in detail in this specification are prior art known to those skilled in the art. Although illustrative specific embodiments of the invention have been described above to facilitate understanding by those skilled in the art, it should be understood that the invention is not limited to the scope of the specific embodiments. Various modifications are readily apparent to those skilled in the art as long as they fall within the spirit and scope of the invention as defined and determined by the appended claims, and all inventions utilizing the concept of this invention are protected.

Claims

1. A method for precision composite machining and forming of L-shaped cross-section ring parts for aero-engines, characterized in that, This includes the following steps performed sequentially: S1, forged ring billet design; S11, Select a rectangular cross-section forged ring blank as the subsequent rolling blank. Combining the dimensions in the L-shaped cross-section ring part design drawing, obtain the dimensions of the L-shaped cross-section ring part by adding machining allowance. Calculate the dimensions of the rectangular cross-section forged ring blank as follows: The height B0 of the rectangular cross-section forged ring blank: B0 = B; The inner diameter d0 of the rectangular cross-section forged ring blank: d0 = (1.2~1.5)d c ; The volume V0 of the rectangular cross-section forged ring blank: Outer diameter D0 of rectangular cross-section forged ring blank: Where B is the total height of the L-shaped cross-section ring, and d c B is the diameter of the mandrel in the forging equipment. b It is the height of the large ring area of ​​the L-shaped cross-section ring component, D. s It is the outer diameter of the small ring of the L-shaped cross-section ring, D. b d is the outer diameter of the large ring of the L-shaped cross-section ring, and d is the inner diameter of the L-shaped cross-section ring. S12, calculate the large ring wall thickness H of the L-shaped cross-section ring member according to the following method. b And the forming limit value H of the large ring wall thickness of the L-shaped cross-section ring. b-max : H b-max =λH s +(1-λ)H0; in, H s It is the thickness of the small ring region of the L-shaped cross-section ring component, and λ is the rolling deformation coefficient of the L-shaped cross-section ring per revolution, and λ is calculated according to the following formula. H0 is the thickness of the rectangular cross-section forged ring blank, and B s It is the height of the small ring of the L-shaped cross-section ring component, and B s =BB b ; S13, Compare the large ring wall thickness H of the L-shaped cross-section ring. b And the forming limit value H of the large ring wall thickness of the L-shaped cross-section ring. b-max ; If H b ≤H b-max Then, jump to S3 and directly use the rectangular cross-section forged ring billet in S11 as the rolling billet for rolling: If H b >H b-max If so, then jump to S2; S2, modify the rectangular cross-section forged ring blank to obtain an optimized L-shaped cross-section forged ring blank: S21, calculate the radius R of the large ring region of the L-shaped cross-section ring member according to the following methods. b And the limiting radius R of the large ring region of the L-shaped cross-section ring component. b-max ; S22, calculate the volume ΔV for correction of rectangular cross-section forging ring billet using the following formula: ΔV=πB b (R b 2 -R b-max 2 ); Assuming the volume V0 and inner diameter d0 of the rectangular cross-section forged ring blank remain constant, the height B of the small ring of the L-shaped cross-section ring is... s Height B of the large ring area of ​​the L-shaped cross-section ring component b The rectangular cross-section forged ring blank is divided into an upper region and a lower region along the axial direction. A volume V1 with a height of Bs is removed from the outer ring of the upper region in the form of a rectangular cross-section ring structure, denoted as V1 = ΔV. Then, ΔV is added to the outer ring of the lower region in the form of a rectangular cross-section ring structure with a height of Bb as a compensation volume V2, thereby obtaining a modified L-shaped cross-section forged ring blank. S23, calculate the corrected outer diameters of the small and large rings of the L-shaped cross-section forged ring blank using V1 and V2. Replace the outer diameter D0 of the rectangular cross-section forged ring blank with the corrected outer diameter of the large ring of the L-shaped cross-section forged ring blank, and then use the calculation method in S12 to obtain the wall thickness H of the large ring of the L-shaped cross-section ring. b And the forming limit value H of the large ring wall thickness of the L-shaped cross-section ring. b-max Then determine H b and H b-max The relationship, if H b ≤H b-max Then jump to S3, if H b >H b-max If the L-section forging ring blank is corrected again, a new L-section forging ring blank will be obtained. S3, rolling forming of ring forgings: For the rectangular cross-section forged ring blank in S11 or the L-shaped cross-section forged ring blank obtained in S23, radial rolling forming is used to obtain the size of the L-shaped cross-section ring with machining allowance; S4, the ring forging is turned into shape, and the axial end face, inner hole and outer circular surface of the L-shaped cross section ring obtained in S3 are machined to obtain the final dimensions in the part design drawing; S5, the ring forging is milled to form the circumferentially distributed holes in the large ring area of ​​the L-shaped cross-section ring to obtain the final dimensions in the part design drawing.

2. The method for precision composite machining and forming of L-shaped cross-section ring parts for aero-engines according to claim 1, characterized in that: In S3, the radial rolling forming device includes a drive roller, a tapered roller, and a core roller. The drive roller rotates actively and contacts the outer ring surface of the rolled ring blank. The core roller makes a radial feed motion and contacts the inner ring surface of the rolled ring blank. The tapered roller presses against the two axial end faces of the rolled ring blank.

3. The method for precision composite machining and forming of L-shaped cross-section ring parts for aero-engines according to claim 2, characterized in that: The radial rolling forming includes the initial rolling biting stage and the stable rolling diameter expansion stage. In the initial rolling stage, the feed speed v1 = (0.2~0.8)v, and in the diameter expansion stage, the feed speed v2 = (1~1.2)v, where v is the core roll feed speed.

4. The method for precision composite machining and forming of L-shaped cross-section ring parts for aero-engines according to claim 3, characterized in that: The core roller feed speed v is calculated using the following formula: Among them, v max It is the maximum feed speed of the mandrel during the rolling process of L-shaped cross-section rings, v min It is the minimum feed speed of the mandrel during the rolling process of L-shaped cross-section ring parts.

5. The method for precision composite machining and forming of L-shaped cross-section ring parts for aero-engines according to claim 3, characterized in that: In step S4, the two axial end faces of the L-shaped cross-section ring are first machined to obtain the machining reference. Then, the inner hole of the L-shaped cross-section ring is machined with the two axial end faces as the reference to obtain the inner hole diameter. Finally, the L-shaped outer circle of the L-shaped cross-section ring is machined to obtain the designed machining dimensions.

6. The method for precision composite machining and forming of L-shaped cross-section ring parts for aero-engines according to claim 5, characterized in that: During the turning process, the cutting feed rate v q Calculate using the following formula: Among them, D q is the outer diameter of the ring forging being machined, and n is the spindle speed of the turning equipment.

7. The method for precision composite machining and forming of L-shaped cross-section ring parts for aero-engines according to claim 5, characterized in that: When the two axial end faces of the L-shaped cross-section ring are machined, the spindle speed n is controlled between 25 and 35 r / min.

8. The method for precision composite machining and forming of L-shaped cross-section ring parts for aero-engines according to claim 5, characterized in that: The two axial end faces, the inner hole, and the L-shaped outer circle are all formed by turning in one step to remove the machining allowance.

9. The method for precision composite machining and forming of L-shaped cross-section ring parts for aero-engines according to claim 1, characterized in that: In step S5, the circumferentially distributed holes of the L-shaped cross-section ring are first milled out using a milling cutter, and then the burrs on the edge of the circumferentially distributed holes are removed and chamfered using a chamfering cutter.

10. The method for precision composite machining and forming of L-shaped cross-section ring parts for aero-engines according to claim 1, characterized in that: In step S5, the first step is to rough mill the circumferentially distributed holes, and the second step is to fine mill and enlarge the holes.

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