An aero-engine closing-in tool and closing-in method

Abstract

The application discloses an aero-engine closing-up tool and a closing-up method, and aims to solve the problems of orifice material wrinkles, cracks and inconsistent quality caused by the traditional impact locking process. The main body of the tool is in a cylindrical shape, and the upper end is an R10 circular arc surface to realize automatic centering. Two inclined surfaces are symmetrically processed on the side wall to provide a rotating avoidance space, and a 30-degree guide inclined surface is arranged on the rotating forward side to smoothly guide the material flow. The pressure head is made of quenched manganese steel, and the hardness reaches HRC58-62, which has excellent wear resistance. The method drives the pressure head to rotate and extrude the part orifice to form by providing constant rotating speed and controllable pressure through the equipment. Before operation, the pressure head with a specific diameter range is matched according to the hole diameter D, and the lubricating grease is applied to reduce wear. The quality is ensured by quantitatively controlling the process parameters and finally detecting the hole diameter D1 after closing-up. The application realizes high quality, high consistency and high efficiency of the closing-up operation, completely avoids the defects of the traditional process, and significantly improves the product life.

Description

Technical Field

[0001] This invention relates to the field of machining technology, specifically to a tooling and method for closing the joint of an aero-engine. Background Technology

[0002] With the rapid development of aero-engine technology, more and more aero-engines are adopting compact and highly reliable locking or safety devices. Extrusion deformation is a locking method that uses the compression of the part itself to cause plastic deformation of the material at the closing point. Its advantages include simplicity, efficiency, reliability, and no increase in part weight. The principle of extrusion deformation safety is to use a harder extrusion head to compress the machined opening. Under the compression of the spherical working surface, the material at the opening undergoes plastic deformation and deforms inward, thus achieving the locking function.

[0003] Currently, in the machining of aero-engines, multiple impacts or hammering of the indenter are used to lock the orifice. While convenient, this method requires repeated hammering or impacts, which can cause the material at the orifice to wrinkle or exceed its plastic deformation limit, leading to localized cracks. This significantly affects machining quality and poses serious safety hazards to engine operation. Therefore, finding a tool and method that can prevent wrinkles or localized cracks in the material at the orifice without hammering is crucial. Summary of the Invention

[0004] The purpose of this invention is to design a tooling fixture that, when installed on a device, applies downward pressure while the device rotates the tooling head. Under this condition, the material at the orifice is squeezed and deformed, thereby locking the orifice.

[0005] The technical solution of the present invention: an aero-engine closing tooling, comprising a cylindrical pressure head body, the upper end face of the pressure head body being constructed as an arc surface, and two symmetrically arranged inclined surfaces on the side wall of the pressure head body, the two inclined surfaces being obliquely cut from the cylindrical side wall; wherein, at the intersection of any of the inclined surfaces and the arc surface, a small triangular inclined surface is further provided, the angle of the small triangular inclined surface being 30°.

[0006] Furthermore, the volume of each of the inclined surfaces accounts for 1 / 3 of the total volume of the cylindrical structure of the pressure head body.

[0007] Furthermore, one end of the pressure head body is integrally connected to a base, and the base has a stepped columnar structure.

[0008] Furthermore, the pressure head is made of manganese steel and is hardened to a hardness of HRC58-62.

[0009] A method for necking using the described aero-engine necking tooling, comprising the following steps: Step S1: Installation and fixation: Install the necking tooling and the aero-engine part to be necked on the processing equipment; Step S2: Tooling selection: According to the aperture D of the target hole on the part to be necked, select a necking tooling with a matching punch diameter d. The selection criteria are as follows: When D ≤ 4 mm, the value range of d is 18 mm to 22 mm; when 4 mm < D < 8 mm, the value range of d is 24 mm to 28 mm; Step S3: Perform necking: Start the equipment, and control the punch to perform rotary extrusion necking operation on the hole opening of the part with set process parameters. Before the operation, apply vaseline grease on the arc surface of the punch; Step S4: Quality inspection: Detect the size after necking and judge whether the necking quality is qualified.

[0010] Further, in the step S1, after installation, the outer circle surface of the part needs to be clamped and aligned to ensure that the radial runout of any four symmetric points on the outer circle surface of the part is not greater than 0.03 mm.

[0011] Further, in the step S3, the set process parameters include punch rotation speed, downward pressure speed and locking depth.

[0012] Further, the specific inspection steps of the step S4 are as follows: Use a dial vernier caliper with a graduation value of 0.01 mm and a measuring range of 0 - 150 mm to measure the aperture D1 after necking. When D1 ≤ D - 0.4 mm, it is judged as qualified Advantages of the present invention: 1. This tooling can quickly and effectively locate the locking position, and at the same time complete the locking efficiently and with high quality. The design of the 30° inclined plane on the rotating side not only effectively reduces the punch wear, but also greatly improves the surface quality at the locking position, and greatly improves the quality consistency of the extrusion locking. It effectively avoids the occurrence of local wrinkles and local cracks at the locking position caused by traditional impact locking, and greatly improves the service life of the product.

[0013] 2. The efficiency is improved. The tooling is designed to be connected to the main shaft of the machining equipment. Utilizing the automation ability of the equipment, it can sequentially and continuously complete the necking of all hole positions quickly, far exceeding the rhythm of manual tapping. Cutting 1 / 3 of the volume of the punch provides the necessary avoidance space for the rotation of the punch, preventing interference with the workpiece or fixture during high-speed rotation, and ensuring the smoothness and uninterrupted operation of the process. Description of the drawings

[0014] To more clearly illustrate the technical solutions in the specific embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a three-dimensional schematic diagram of the locking tooling of the present invention; Figure 2 This is a plan view of the locking fixture of the present invention; Figure 3 This is a schematic diagram of using the locking fixture of the present invention for locking; Figure reference numerals: D - hole diameter; D1 - diameter of the locking hole after closing; d - diameter of the pressure head. Detailed Implementation

[0016] 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.

[0017] Example 1: A tooling for a low-pressure turbine rotor head retraction of an aero-engine, referring to... Figure 1 and Figure 2 .

[0018] This embodiment aims to provide a pressure head fixture specifically designed for the closing of pin holes in low-pressure turbine rotors of aero-engines. Its core principle is to utilize the stable rotational motion and constant axial feed provided by the equipment to drive the pressure head to continuously and uniformly compress the material at the hole opening, causing plastic deformation and flow towards the center, thereby achieving the locking function. This method, by controlling the uniform deformation, fundamentally avoids the material wrinkling or micro-cracks caused by the instantaneous and enormous stress concentration in traditional impact-type locking mechanisms.

[0019] This invention solves the quality problem of mounting pin holes for the guide vanes of a certain type of aero-engine in the traditional impact locking process. The impact process easily leads to uneven deformation of the powder superalloy material, resulting in local wrinkles, or local deformation exceeding the material's limits, causing cracks, which seriously affects the reliability and service life of the product.

[0020] The pressure head fixture comprises an integrally formed pressure head working section and a mounting base. The pressure head working section is cylindrical with an arc-shaped upper surface. This arc-shaped surface is used for contact and extrusion with the workpiece orifice and provides automatic centering during the initial stage of operation. Two symmetrical bevels are machined on the sidewalls of the cylindrical working section, each bevel removing approximately 1 / 3 of the original cylindrical volume. This design provides clearance for pressure head rotation, preventing interference with the workpiece or fixture, while maintaining sufficient structural strength. At any intersection of the two bevels and the arc-shaped surface, a small 30° triangular bevel is machined. This bevel, located on the front side in the direction of rotation, smoothly guides material flow during extrusion, prevents sharp edges from cutting the material, and ensures a high-quality finishing surface. The mounting base has a stepped shaft structure for reliable connection to the equipment spindle, ensuring transmission stability and coaxiality.

[0021] The pressure head is made of high-quality high-manganese steel through a quenching process, and its overall hardness reaches HRC58~62. It has extremely high wear resistance and deformation resistance to withstand the huge deformation resistance of powder high-temperature alloy and the high temperature generated by extrusion.

[0022] The rotary extrusion technique employed in this fixture ensures uniform material deformation, completely eliminating the risk of wrinkles and cracks. Controllable equipment parameters guarantee consistent quality at each locking point. High-hardness, highly wear-resistant materials and a lubrication design significantly extend the fixture's service life. Automatic centering of the arc surface reduces alignment difficulty and improves operational efficiency.

[0023] Example 2: Refer to Figure 3 A method for closing the bore of aero-engine parts with small diameter (D ≤ 4mm) This embodiment provides a method for closing mounting pin holes with a diameter of no more than 4 mm, specifically applied to key components such as low-pressure turbine rotors of aero engines.

[0024] The closing pressure head tooling described in Example 1 is selected, and the diameter d of the working part of the pressure head is selected from 18mm to 22mm. The optimal size can be selected by experimentation within this range according to the specific hole diameter D. The final goal is to meet the technical requirement that the hole diameter D1 after closing should be ≤ D- 0.4mm. For example, for a Φ4mm hole, the hole diameter after closing should be ≤Φ3.6mm.

[0025] The sealing method is as follows: S1: Preparation: Clean the workbench and the clamping surface of the part to ensure there are no burrs or protrusions. Clamp the part on the equipment, align its outer circular surface, and ensure that the runout of the four symmetrical points is no more than 0.03mm.

[0026] S2: Install the fixture. Install the selected pressure head fixture on the main shaft of the equipment and check that its arc surface is smooth and free of defects.

[0027] S3: Centering and lubrication. Adjust the equipment to roughly align the axis of the punch with the axis of the hole to be收口. Apply a uniform layer of vaseline grease on the arc surface of the punch to reduce the frictional resistance and frictional heat and protect the tooling.

[0028] S4: Set parameters. Set the processing parameters of the equipment, including the rotational speed of the punch to provide a constant rotational speed, the downward pressure speed to control the axial feed speed, and the locking depth to control the final position of the extrusion forming.

[0029] S5: Perform the收口. Start the equipment. The punch rotates and feeds downward at the same time to uniformly extrude and收口 the hole opening.

[0030] S6: Inspection: Use a dial vernier caliper with a least count of 0.01 mm to measure the aperture D1 after收口. If D1 ≤ D - 0.4 mm, it is judged as qualified.

[0031] This method realizes high-quality and non-damaging收口 of small and precise hole openings by matching an optimized tooling with a specific size range and a controllable process for small-aperture parts, ensuring the connection reliability of key components of aeroengines.

[0032] Example 3: A method for收口 of aeroengine parts with medium apertures (4 mm < D < 8 mm) This example provides a method for收口 of mounting pin holes with apertures between 4 mm and 8 mm.

[0033] Select the收口 punch tooling as in Example 1, and the diameter d of the working part of the punch is selected within the range of 24 mm to 28 mm. Conduct experimental optimization within this range according to the specific aperture D, and the ultimate goal also meets the technical requirement that the aperture D1 ≤ D - 0.4 mm after收口.

[0034] The steps of this method are exactly the same as those in Example 2, including preparation, installation, centering and lubrication, parameter setting, performing收口, and inspection. The core difference is that the diameter d of the punch used is larger to adapt to a larger aperture, ensuring sufficient extrusion contact area to generate the required amount of plastic deformation.

[0035] This method expands the applicable range of the rotary extrusion收口 process and can achieve the same high-quality收口 operation for parts with medium apertures. It proves that the tooling of the present invention can meet the processing requirements of products with different specifications through serialized design, and has wide applicability and good engineering promotion value.

[0036] The foregoing has provided a detailed description of the aero-engine sealing tooling and sealing method provided by this invention. Specific examples have been used to illustrate the structure and working principle of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims of this invention.

Claims

1. A tooling for closing the nozzle of an aero-engine, characterized in that: The device includes a cylindrical indenter body with an arc-shaped upper surface. The side wall of the indenter body has two symmetrically arranged inclined surfaces, which are obliquely cut from the cylindrical side wall. One end of the indenter body is integrally connected to a base, which has a stepped columnar structure. The indenter is made of manganese steel and has been hardened to a hardness of HRC58-62. Wherein, at the intersection of any of the inclined planes and the arc surface, a small triangular inclined plane is also provided, and the angle of the small triangular inclined plane is 30°; The finishing method using finishing fixtures includes the following steps: Step S1: Installation and fixing: Install the closing fixture and the aero-engine part to be closed onto the processing equipment; Step S2: Tooling selection. Based on the diameter D of the target hole on the aero-engine part to be closed, select a closing tooling that matches the diameter d of the pressure head. The selection criteria are: when D ≤ 4 mm, the value of d ranges from 18 mm to 22 mm; when 4 mm < D < 8 mm, the value of d ranges from 24 mm to 28 mm. Step S3: Perform the closing operation. Start the equipment and control the pressure head to perform a rotary extrusion closing operation on the opening of the part according to the set process parameters. Before the operation, apply petroleum jelly grease to the arc surface of the pressure head. Step S4: Quality inspection, check the dimensions after sealing, and determine whether the sealing quality is qualified.

2. The aero-engine retraction fixture according to claim 1, characterized in that: Each of the inclined planes accounts for 1 / 3 of the total volume of the cylindrical structure of the pressure head body.

3. A closing method using the aero-engine closing fixture as described in claim 1 or 2, characterized in that, Includes the following steps: Step S1: Installation and fixing: Install the closing fixture and the aero-engine part to be closed onto the processing equipment; Step S2: Tooling selection. Based on the diameter D of the target hole on the aero-engine part to be closed, select a closing tooling that matches the diameter d of the pressure head. The selection criteria are: when D ≤ 4 mm, the value of d ranges from 18 mm to 22 mm; when 4 mm < D < 8 mm, the value of d ranges from 24 mm to 28 mm. Step S3: Perform the closing operation. Start the equipment and control the pressure head to perform a rotary extrusion closing operation on the opening of the part according to the set process parameters. Before the operation, apply petroleum jelly grease to the arc surface of the pressure head. Step S4: Quality inspection, check the dimensions after sealing, and determine whether the sealing quality is qualified.

4. The closing method according to claim 3, characterized in that, In step S1, after installation, the outer circular surface of the part needs to be clamped and aligned to ensure that the radial runout of any four symmetrical points on the outer circular surface of the part is not greater than 0.03 mm.

5. The closing method according to claim 3, characterized in that, In step S3, the set process parameters include punch rotation speed, pressing speed, and locking depth.

6. The closing method according to claim 3, characterized in that, The specific inspection steps of step S4 are as follows: Use a dial caliper with a scale division of 0.01 mm and a range of 0-150 mm to measure the diameter D1 of the hole after closing. When D1 ≤ D -0.4 mm, it is judged to be qualified.

7. The closing method according to claim 3, characterized in that, The aero-engine part to be closed is the mounting pin hole on the low-pressure turbine rotor of the aero-engine.

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