An end face processing method suitable for split ring type parts

Abstract

The application discloses a kind of end face processing methods suitable for open ring class parts, belong to the field of aero-engine parts machining technology, the method uses assembly fixture auxiliary processing, the fixture includes clamping body, tensioning chuck and tailstock;Clamping body has once processing forming reference external circle face and reference end face.Processing, first, after the part is radially compressed, it is loaded into clamping body, and the end face of the part is gapless with reference end face by using roller type compression tooling;Tensioning chuck and tailstock are loaded again, and the tensioning chuck is radially expanded by the axial force of tailstock, and the part is radially compressed on the reference end face, the radial movement is limited, and the end face does not produce disengagement torque;Then, the roundness of reference external circle face is aligned, and the parallelism between the end face to be processed and the abutting end face is indirectly ensured;Finally, the end face is turned.The application replaces lapping with turning, and the processing efficiency is high, the quality is stable, the clamping and processing deformation can be effectively controlled, and the parallelism and flatness requirements of end face are stably ensured.

Description

Technical Field

[0001] This invention relates to the field of aero-engine parts processing technology, and specifically to a method for processing the end face of open ring-type parts. Background Technology

[0002] In the manufacturing process of aero-engine parts, there exists an extremely thin and easily deformable open ring component. This type of component is characterized by: a thickness W1 less than 3mm, an outer diameter Φ1 greater than 130mm, an inner diameter Φ2 greater than 125mm, and a ring width less than 5mm; at one circumference, there is an extremely small, slanted opening with a width W2 less than 3mm, as shown in the reference... Figure 1 - Figure 3 Due to the aforementioned structural features, this part is highly susceptible to deformation during machining. Furthermore, it requires extremely high flatness of the end face and parallelism between the two end faces, with the parallelism between the two end faces required to be no greater than 0.025mm. Conventional end face grinding or lapping methods are insufficient to meet these precision requirements for parallelism and flatness.

[0003] In the prior art, CN116213768B discloses a turning fixture and process for thin-walled ring-shaped parts. This solution includes a three-jaw chuck, comprising a jaw body and three jaws evenly spaced circumferentially on the top of the jaw body. Each jaw has a fixed arc-shaped stop parallel to the top of the jaw body, and the three arc-shaped stops have the same curvature and do not contact each other. The top surface of the arc-shaped stops has multiple radially inwardly oriented steps, which are wider in the middle and narrower at both ends, and are of equal thickness axially. The clamping force of this fixture mainly comes from the resistance generated by the cutting tool on the workpiece. Therefore, a smaller initial clamping force can be used to clamp the three-jaw chuck, thereby greatly reducing the radial deformation and axial warping of the workpiece during the initial clamping process, thus improving the machining accuracy of the workpiece.

[0004] However, for the aforementioned ultra-thin open-face ring parts with extremely small inclined openings, their rigidity is weaker and their deformation sensitivity is higher. The clamping methods used in the existing technologies may still cause slight uneven deformation of the end faces during processing, making it difficult to reliably meet the high precision requirements of the parts for the parallelism and flatness of the two end faces. Therefore, it is necessary to seek a processing method and fixture that can more effectively control clamping and processing deformation and reliably guarantee the parallelism and flatness requirements of the end faces. Summary of the Invention

[0005] The purpose of this invention is to provide a method for machining the end face of open ring-type parts, mainly to solve the deformation problem that occurs during the machining of the end face of the open ring part shown in the figure.

[0006] The technical solution of this invention: A method for machining the end face of open ring-shaped parts, using an assembly fixture for auxiliary machining. The assembly fixture includes a fixture body, which has a reference outer circular surface A and a reference end face B, both machined in one step, satisfying a preset perpendicularity requirement. The reference end face B of the fixture body is equipped with a tensioning disc for clamping the part, and a center is provided at the center of the fixture body and the tensioning disc. The machining method includes the following steps: Step 1: Clamp the part. After compressing the open ring part radially, install it into the clamping body. Use a clamping tool to tightly fit the first end face of the part with the reference end face B of the clamping body to ensure that there is no gap between the first end face of the part and the reference end face B during the processing. Step 2: Install the tensioning disc and the center in sequence. Apply axial force through the center to make the tensioning disc radially press the part onto the reference end face B. Step 3: Datum alignment. Align the circular runout of the datum outer circular surface A of the fixture. By ensuring the coaxiality of the datum outer circular surface A with the machine tool spindle, the parallelism between the second end face of the part being machined and the first end face it is mating with is indirectly ensured. Step 4: Turning: The second end face of the part is turned.

[0007] Furthermore, the clamp is a disc structure with a mounting hole at its center and a stepped mounting groove on one end face. The upper stepped surface of the stepped structure forms the reference end face B. An annular groove is formed on the side wall of the disc, and the circumferential end face of the annular groove forms the reference outer circular surface A. The perpendicularity between the reference end face B and the reference outer circular surface A is not greater than 0.002 mm.

[0008] Furthermore, the tensioning disc is an annular disc structure with a through mounting hole at its center. The annular disc has multiple evenly distributed radial slots extending radially outward from the inner ring, and independent elastic tensioning flaps are formed between adjacent radial slots. The outer end face of the tensioning flap is used to press the inner ring end face of the part, and the radial slots are positioned to avoid the inclined opening of the part.

[0009] Furthermore, the tip is a one-piece cylinder, and its working end acting on the tensioning disc is a conical structure. Furthermore, the tip passes sequentially through the mounting holes of the tensioning disc and the clamping body. The conical working end of the tip applies an axial clamping force to the tensioning disc. Under the action of the axial clamping force, each elastic tensioning disc expands radially outward, and the outer end face of the tensioning disc contacts the inner ring end face of the part, restricting the radial movement of the part.

[0010] Furthermore, the clamping fixture is a roller-type clamping device, which includes a handle, a rotating shaft, and a roller rotatably connected to the rotating shaft; during the clamping operation, the outer circular surface of the roller forms a rolling contact with the second end face of the part, so as to tightly fit the first end face of the part against the reference end face B.

[0011] Furthermore, in the reference alignment described in step 3, the perpendicularity deviation between the first end face of the clamped part and the reference outer circular surface A is indirectly determined by aligning the circular runout of the reference outer circular surface A, so that the parallelism between the second end face of the part and the first end face meets the preset accuracy requirements after the turning process in step 4.

[0012] Furthermore, the reference end face B of the clamping body itself has a preset flatness accuracy; in step 1, the clamping fixture ensures that the first end face of the part is tightly fitted with the reference end face B without gap, so that the flatness of the second end face of the part after turning meets the preset accuracy requirements.

[0013] The beneficial effects of this invention are: First, by using the high-precision reference outer circular surface and reference end face on the fixture, the complex end face alignment problem is transformed into a simple circular runout alignment problem, which reduces the difficulty of operation and the dependence on the operator's technical level.

[0014] Secondly, the use of roller-type clamping fixtures achieves gapless fit of the end face of the parts. Combined with the radial uniform tensioning of the tensioning disc, the parts are subjected to reasonable force during clamping, and clamping deformation that would cause end face warping or body twisting will not occur. This solves the technical problem of easy deformation of ultra-thin open ring parts during processing.

[0015] Third, compared with grinding, turning has significantly improved efficiency, stable processing quality, and a significantly higher pass rate, and almost no parts will be scrapped due to processing deformation. Attached Figure Description

[0016] 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.

[0017] Figures 1-3 Schematic diagram of an extremely thin and easily deformable open ring component; Figures 4-7 This is a schematic diagram of the fixture assembly and top clamping of the present invention; Figure 8 This is a schematic diagram of the clamping fixture structure; Figures 9-11 This is a schematic diagram of the clamp body structure; Figures 12-14 This is a schematic diagram of the tensioning coil structure; Reference numerals in the attached drawings: 1-clamp body; 2-open ring; 3-tensioning disc; 4-center; 5-clamping fixture; 51-roller; 52-rotating shaft; 53-handle; A-reference outer circular surface; B-reference end face. Detailed Implementation

[0018] 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.

[0019] Example 1: This example provides an assembly fixture for machining the end face of open ring-shaped parts, the structure of which is as follows. Figures 4 to 14 .

[0020] The assembly fixture consists of a fixture body 1, a tensioning disc 3, a center 4, and a clamping fixture 5. The fixture body 1 is used to accommodate and position the open ring part 2. The tensioning disc 3 and the center 4 cooperate to achieve radial clamping of the part. The clamping fixture 5 assists in achieving gapless contact between the end face of the part and the reference end face of the fixture during the clamping process.

[0021] Reference Figures 9 to 11 The fixture body 1 is a disc structure with an axially penetrating mounting hole at its center for inserting the center point 4. One end face of the fixture body 1 has a stepped mounting groove for accommodating the open ring part 2; wherein, the upper stepped surface of the stepped structure forms a reference end face B for tightly fitting with the first end face (i.e., the unmachined end face) of the part 2.

[0022] An annular groove is formed on the side wall of the disc in the fixture body 1. The circumferential end face of this annular groove is precision-machined to form the reference outer circular surface A. The reference outer circular surface A and the reference end face B are machined in the same clamping operation, and they meet the preset perpendicularity requirements. Specifically, the perpendicularity between the reference end face B and the reference outer circular surface A is no greater than 0.002 mm. The flatness of the reference end face B itself is also no greater than 0.002 mm. By ensuring the high-precision positional relationship between the reference outer circular surface A and the reference end face B, it is possible to indirectly determine the perpendicularity state between the first end face of the workpiece and the machine tool spindle after clamping by simply correcting the circular runout of the reference outer circular surface A during machining.

[0023] Reference Figures 12 to 14The tensioning disc 3 is an annular disc structure with a through-hole in its center for the center point 4 to pass through. Multiple evenly distributed radial slots are formed radially outward from the inner ring of the annular disc, with independent elastic tensioning flaps formed between adjacent slots. Each elastic tensioning flap has a certain radial elastic deformation capacity, and its outer end face is used to contact the inner ring end face of part 2 and apply radial clamping force. Specifically, the radial slots on the tensioning disc 3 are designed in the circumferential direction to avoid obstructing the inclined openings on part 2. Thus, when the tensioning flaps of the tensioning disc 3 expand outward, the clamping force can be evenly applied to the entire inner ring wall of part 2, avoiding insufficient clamping or stress concentration caused by the slots aligning with the openings of the part.

[0024] Reference Figures 4 to 7 The tip 4 is a one-piece cylindrical structure, and its working end acting on the tensioning disc 3 is a conical structure. The tip 4 passes through the central mounting hole of the tensioning disc 3 and the central mounting hole of the clamping body 1 in sequence. When the tip 4 is subjected to external axial thrust, its conical working end applies axial clamping force to the inner ring of the tensioning disc 3. Under the action of the conical surface, this axial force is converted into a radial component force, causing each elastic tensioning petal of the tensioning disc 3 to expand radially outward. The outer end face of the tensioning petal contacts the inner ring end face of the part 2, thereby radially pressing the part 2 into the mounting groove where the reference end face B of the clamping body 1 is located, restricting the radial movement of the part during the processing.

[0025] The characteristic of this clamping method is that the axial force applied by the tip 4 is mainly used to drive the tensioning disc 3 to expand, which generates a clamping force acting radially on the inner wall of the part, without generating an axial component force that causes the first end face of the part to separate from the reference end face B or warping deformation of the part body due to excessive clamping force. This ensures that the end face of the part is not disturbed by the radial clamping process.

[0026] Reference Figure 8 The clamping fixture 5 is a roller-type clamping device, which includes a handle 53, a rotating shaft 52, and a roller 51 rotatably connected to the rotating shaft 52. During the part clamping process, the operator holds the handle 53 and presses the outer surface of the roller 51 against the second end face (i.e., the end face to be machined) of the part 2, applying axial thrust to make the first end face of the part 2 tightly fit against the reference end face B of the fixture body 1. Since the roller 51 and the end face of the clamped part are in rolling contact, the clamping fixture 5 can be flexibly adjusted in position during clamping and subsequent turning processes, which can ensure effective fit of the end face of the part and avoid motion interference with the turning tool.

[0027] Example 2: This example provides a method for machining the end face of an open ring part using the assembly fixture described in Example 1. The machining method includes the following steps.

[0028] Step 1: Clamping the part and aligning it with the reference end face. First, pre-cleaning the open ring part 2 is performed. Since the part has an inclined opening, a slight compressive force can be applied radially to slightly reduce its outer diameter before placing part 2 into the stepped mounting groove of the fixture 1. Then, the clamping fixture 5 is used to axially clamp part 2. Specifically, the operator holds the handle 53 of the clamping fixture 5 and places the outer surface of the roller 51 against the second end face of part 2 (i.e., the end face to be machined later), applying axial thrust to ensure that the first end face of part 2 (i.e., the non-machined end face) is tightly fitted with the reference end face B of the fixture 1. During clamping, the part can be rotated or the roller position moved appropriately to ensure uniform force distribution across the end face of the part, eliminating any gaps and ensuring that the first end face of the part and the reference end face B remain in close contact without any gaps during machining.

[0029] Step 2: Install the tensioning disc and center to complete radial clamping. After part 2 is axially fitted, install the tensioning disc 3 and center 4 in sequence. Place the tensioning disc 3 into the inner ring area of ​​part 2, ensuring that the outer ends of each elastic tensioning flap align with the inner ring end face of part 2, and confirm that the radial slot has avoided the inclined opening of the part. Insert the center 4 through the center mounting hole of the tensioning disc 3 and through the center mounting hole of the fixture 1. Apply axial thrust to the center 4 using external power (such as a machine tool tailstock), and the tapered working end of the center 4 forces each elastic tensioning flap of the tensioning disc 3 to expand radially outward evenly. The outer ends of the tensioning flaps contact the inner ring end face of part 2, applying a uniform radial clamping force to part 2, reliably fixing part 2 in the mounting slot of the fixture 1 and limiting its radial movement during processing. Since the radial clamping force acts directly on the inner wall of the part, and its force line is parallel to the reference end face B, it will not generate an axial warping moment that causes the end face of the part to separate from the reference end face B.

[0030] Step 3: Datum Alignment. The entire assembly fixture with the completed parts clamped is mounted on the lathe spindle using a three-jaw chuck. During clamping, the jaws of the three-jaw chuck hold the outer cylindrical surface of fixture body 1. Datum alignment is then performed: using a dial indicator or micrometer, the circular runout of the datum outer cylindrical surface A on fixture body 1 is checked. The overall position of the fixture is adjusted until the circular runout of the datum outer cylindrical surface A is no greater than 0.005 mm.

[0031] The principle behind this alignment step is as follows: the datum outer cylindrical surface A and the datum end face B are formed in a single clamping operation, and their perpendicularity is no greater than 0.002mm. When the circular runout of the datum outer cylindrical surface A is corrected to within 0.005mm, it can be determined that the perpendicularity deviation between the first end face of the clamped part 2 (which is in contact with the datum end face B) and the rotation axis of the machine tool spindle is no greater than 0.007mm. Under the condition that the machine tool's own accuracy is 0.002mm, when the tool feeds along a plane perpendicular to the spindle axis, the parallelism of the second end face of the machined part relative to the first end face can be controlled within 0.009mm, meeting the design requirement of a parallelism of no more than 0.025mm.

[0032] Step 4: Turning. Start the machine tool and use a turning tool to turn the second end face of part 2. Since the first end face of part 2 is in close contact with the reference end face B, and the flatness of the reference end face B itself is no greater than 0.002mm, under the condition that the machine tool's own accuracy is 0.002mm, the flatness of the second end face of the part obtained after turning can be controlled within 0.004mm, which meets the high precision requirements of the part for the flatness of the end face.

[0033] After machining, loosen the center 4, remove the tensioning disc 3, and the machined open ring part 2 can be taken out from the fixture 1. Inspection shows that the parallelism of the two end faces of the machined part is no greater than 0.025mm, the flatness of the end faces meets the design requirements, and no unacceptable deformation occurred during the machining process.

[0034] The foregoing has provided a detailed description of an end-face processing method for open ring-type parts provided by the present invention. Specific examples have been used to illustrate the structure and working principle of the invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A method for machining the end face of open ring-shaped parts, characterized in that: The assembly fixture is used for auxiliary processing. The assembly fixture includes a fixture body (1). The fixture body (1) has a reference outer circular surface (A) and a reference end face (B) formed in one operation. The two meet the preset perpendicularity requirements. The reference end face (B) of the fixture body (1) is equipped with a tensioning disc (3) for clamping the parts. A center point (4) is provided at the center of the fixture body (1) and the tensioning disc (3). The processing method includes the following steps: Step 1: Clamp the part, compress the open ring part radially and then put it into the clamping body (1), and use a clamping tool (5) to tightly fit the first end face of the part with the reference end face (B) of the clamping body (1) to ensure that there is no gap between the first end face of the part and the reference end face (B) during the processing. Step 2: Insert the tensioning disc (3) and the center (4) in sequence, and apply axial force through the center (4) so ​​that the tensioning disc (3) radially presses the part onto the reference end face (B); Step 3: Base alignment, align the runout of the base outer circular surface (A) of the fixture body (1), and indirectly ensure the parallelism between the second end face of the part being machined and the first end face that is attached by ensuring the coaxiality of the base outer circular surface (A) and the machine tool spindle. Step 4: Turning: Turn the second end face of the part.

2. The end face machining method for open ring-shaped parts according to claim 1, characterized in that: The clamping body (1) is a disc structure with a mounting hole at its center and a stepped mounting groove on one end face. The upper stepped surface of the stepped structure forms the reference end face (B). An annular groove is provided on the side wall of the disc, and the circumferential end face of the annular groove forms the reference outer circular surface (A). The perpendicularity between the reference end face (B) and the reference outer circular surface (A) is not greater than 0.002 mm.

3. The end face machining method for open ring-shaped parts according to claim 1, characterized in that: The tensioning disc (3) is an annular disc structure with a through mounting hole in the center. The annular disc has multiple evenly distributed radial slots from the inner ring outwards, and independent elastic tensioning flaps are formed between two adjacent radial slots. The outer end face of the tensioning flap is used to press the inner ring end face of the part, and the position of the radial slots avoids the inclined opening of the part.

4. The end face machining method for open ring-shaped parts according to claim 1, characterized in that: The tip (4) is an integral cylinder, and its working end that acts on the tensioning disc (3) is a conical structure.

5. The end face machining method for open ring-shaped parts according to claim 4, characterized in that: The tip (4) passes through the mounting holes of the tensioning disc (3) and the clamping body (1) in sequence. The conical working end of the tip (4) applies an axial clamping force to the tensioning disc (3). Under the action of the axial clamping force, each elastic tensioning disc (3) expands outward in the radial direction and contacts the inner ring end face of the part through the outer end face of the tensioning disc, thus restricting the radial movement of the part.

6. The end face machining method for open ring-shaped parts according to claim 1, characterized in that: The clamping fixture (5) is a roller-type clamping device, which includes a handle (53), a rotating shaft (52) and a roller (51) rotatably connected to the rotating shaft (52). During the clamping operation, the outer circular surface of the roller (51) forms a rolling contact with the second end face of the part to tightly fit the first end face of the part against the reference end face (B).

7. The end face machining method for open ring-shaped parts according to claim 1, characterized in that: In the reference alignment described in step 3, the perpendicularity deviation between the first end face of the clamped part and the reference outer circular surface (A) is indirectly determined by aligning the circular runout of the reference outer circular surface (A), so that the parallelism between the second end face of the part and the first end face meets the preset accuracy requirements after the turning process in step 4.

8. The end face machining method for open ring-shaped parts according to claim 1, characterized in that: The reference end face (B) of the fixture (1) has a preset flatness accuracy. In step 1, the clamping fixture (5) ensures that the first end face of the part is in close contact with the reference end face (B) without gap, so that the flatness of the second end face of the part after turning meets the preset accuracy requirements.

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