A method to replace five-axis machining of support plate housing

Abstract

A method to replace five-axis machining of a support plate housing involves: rough turning or milling the inner and outer rings of the support plate housing blank; semi-finish turning the inner and outer rings of the housing and enlarging the locating holes; semi-finish milling the air-side cavity, semi-finish milling the air-inlet side cavity, finish milling the air-out side cavity, and finish milling the air-inlet side cavity on a special tooling; rough milling the inner cavity and flow channel of the workpiece on a three-axis vertical machining center, leaving a margin at the junction of the inner and outer flow channels of the workpiece and the position where the support plate and the flow channel intersect, polishing the datum surface, semi-finish turning the air-out side flow channel surface and the outer surface, and then semi-finish turning the air-inlet side flow channel surface and the inner cavity; after completing the enlarging of the locating pin hole of the workpiece on the three-axis vertical machining center, mounting the tooling on the three-axis machine tool, installing the workpiece, and starting the semi-finish milling of the air-out side cavity by rotating the handle of the manual turntable and positioning it with the double-cone contact locating pin to complete the milling.

Description

Technical Field

[0001] This invention relates to a method for machining a support plate housing and a double-cone self-centering tooling, particularly a machining method using a three-axis vertical machining center. Background Technology

[0002] The support plate casing (and similar ring-shaped parts requiring high machining precision) is an essential component of modern aero engines. The support plate casing is a double-ringed structure with evenly or unevenly distributed connecting parts between the two rings, such as support plates (which can be blades). During production, the inner and outer flow channels of the casing, as well as the support plates, must be milled (e.g., ...). Figure 1 (i.e., double rings and support plates), which requires removing a large amount of material while ensuring the dimensional accuracy of the flow channel and support plates.

[0003] Due to the design requirements of modern aero engines, the inner and outer flow channels of the support plate casing are, in most cases, approximately conical, while the cross-section of the support plate is similar to a spindle. This makes it impossible to directly machine the workpiece using three-axis or four-axis machining equipment. Five-axis machining equipment must be used to ensure that the workpiece is machined completely according to the design requirements, which increases the cost significantly. Furthermore, due to the limitations of the rotary spindle head structure of five-axis machine tools (generally, support plate casings require gantry-type five-axis machining centers), the tool overhang is very long, making it prone to sudden situations such as tool vibration during machining, resulting in tool damage and low efficiency.

[0004] Three-axis machining centers are relatively simple, with X, Y, and Z axes. Five-axis machining centers add a rotary axis and a oscillating axis to the three-axis system. The rotary axis can be the A-axis, B-axis, or C-axis (axises rotating around the X, Y, and Z axes are respectively called A-axis, B-axis, and C-axis). The rotary axis can rotate 360 ​​degrees. The oscillating axis is one of the two remaining axes (such as B or C) after the rotary axis (e.g., A-axis). The oscillating axis can only oscillate within a certain angle (e.g., ±90 degrees) and cannot rotate 360 ​​degrees. In summary, the five axes of a five-axis machining center generally have three configurations: XYZAB, XYZAC, or XYZBC.

[0005] Compared to traditional three-axis machining centers, five-axis CNC machining centers are more efficient and generally produce better surface finishes. They can also machine workpieces that three-axis machining centers cannot, as they maintain optimal cutting conditions and avoid tool interference. Three-axis machining centers, due to interference, cannot meet process requirements and therefore generally cannot machine parts used in aerospace applications such as impellers, blades, and integral bladed disks. Five-axis machining centers can use shorter tools, increasing system rigidity, reducing the number of tools, and avoiding the need for specialized tools, effectively preventing tool interference.

[0006] Five-axis machining centers can reduce datum conversions and clamping times, completing machining of five sides in one clamping. However, the operating cost of five-axis machining is much higher, and the time cost is also much higher. The machining efficiency is not high. For example, in the usually long automatic machining process, even a small quality defect can scrap the entire workpiece. Summary of the Invention

[0007] To address the above problems, the purpose of this invention is to propose an alternative to a five-axis machining support plate housing. Figure 1 The structure of the support plate casing includes: exhaust side A, intake side B, support plate C, outer flow channel D, and inner flow channel E. The support plate casing can be machined on an 805 three-axis vertical machining center by designing a set of tooling.

[0008] The technical solution of the present invention is a method to replace the five-axis machining of the support plate housing. The method involves rough turning or milling the double rings of the support plate housing blank, i.e., the inner and outer rings of the housing with the support plate structure between the double rings, and semi-finish turning the inner and outer rings of the housing. The method also involves semi-finish turning the exhaust side flow channel surface and the outer surface, semi-finish turning the inlet side flow channel surface and the inner cavity, and widening the positioning hole. Finally, the method involves semi-finish milling the exhaust side cavity, semi-finish milling the inlet side inner cavity, finish milling the exhaust side inner cavity, and finish milling the inlet side inner cavity on a special tooling.

[0009] On a three-axis vertical machining center, rough milling is performed on the inner cavity and flow channel of the workpiece. The inner and outer flow channels of the workpiece, as well as the position where the support plate and the flow channel intersect, are left with a certain amount of allowance. The reference surface is polished, and the air outlet flow channel surface and outer surface are semi-finished. Then, the air inlet flow channel surface and inner cavity are semi-finished. This completes the semi-finishing of the workpiece in the turning process.

[0010] After completing the enlargement of the positioning pin hole of the workpiece on the three-axis vertical machining center, the tooling is mounted on the three-axis machine tool. After the workpiece is installed, the semi-finish milling of the air outlet side cavity can begin. By rotating the handle of the manual turntable and cooperating with the double conical surface contact positioning pin, the exposed side is machined. The same method is used to complete the semi-finish milling of the air inlet side cavity, completing the semi-finish machining process of the entire part and removing all the excess material left by rough milling.

[0011] The reference surface is re-polished, and the flow channel portion extending beyond the support plate on the exhaust side of the workpiece is precision machined into place. The same method is used to precision machine the flow channel portion extending beyond the support plate on the intake side of the workpiece. The workpiece is then mounted and clamped on the machine tool fixture, which incorporates a sliding block and locating pin. After clamping, one inner cavity area on the exhaust side (the machined surface seen from above) of the workpiece is machined into place. The workpiece is then rotated by a manual turntable at a certain angle and positioned using a double-cone locating device. Another (adjacent) inner cavity area is then machined. This process is repeated until all inner cavities with support plate structures between the two rings are machined, connecting the curved surfaces of the inner cavities. The same method is used to machine the inner cavity on the intake side of the workpiece (the machined surface seen from below).

[0012] After the internal cavity is finished, the workpiece is left in a free state for a period of time before finish turning it. First, the outer surface of the exhaust side of the workpiece is finish turned into place. Then, the workpiece is flipped over, and the inner cavity surface of the intake side is finish turned. This completes the finish turning of the part.

[0013] After drilling the air-side mounting holes as required, the workpiece is flipped over and then clamped using a two-pin clamping method on one side to complete the machining of the air-side mounting holes. Next, it undergoes finishing to remove burrs, flash, etc., accumulated during machining. Finally, after passing a fluorescent inspection, it is sent to the final inspection department for a final inspection of all dimensions. Once qualified, it is put into storage. This completes the machining of the entire workpiece.

[0014] The special tooling consists of four parts: a base, a rotary mechanism, a self-centering mechanism, and a double-cone angular positioning mechanism.

[0015] (1) The base part is composed of the 6th screw and the positioning pin fixing the support plate to the base with two included angles in two directions;

[0016] (2) The rotary mechanism is fixed on the base support plate. The rotary mechanism is fixed on the base plate above the manual turntable by the 5th screw through the 2nd T-block. The turntable is rotated by rotating the handle on the manual turntable to obtain different angles.

[0017] (3) Self-centering mechanism: The self-centering mechanism is fixed on the base plate above the manual turntable. The self-centering mechanism is a three-jaw structure for fixing the workpiece. The three-jaw structure includes a circular base plate indexing plate. Three T-slots are evenly provided on the base plate. A pull plate is installed in each T-slot. The outer surface of the pull plate is a T-rail embedded in the T-slot. A T-slot is provided in the center of the pull plate along the length direction. The position of the pull plate near the center of the circular base plate is an inclined T-rail. The center of the circular base plate is a stepped hole. A centering ring is installed on the outer diameter step of the stepped hole. Three slots are provided on the circumference of the centering ring corresponding to the position of the inclined T-rail near the center of the circular base plate of the three pull plates. Each slot is provided with an inclined surface that matches the lower end of the inclined T-rail. Align the oblique T-slots of the three pull plates with the centering ring's center, and insert T-blocks into their corresponding T-slots on the base plate. Push them towards the center until they are in the correct positions. Place the centering ring in the center hole of the base plate, and simultaneously adjust the positions of the oblique T-slot heads of the three pull plates so that all three pull plates are inserted into their corresponding oblique T-slots on the centering ring. Press the centering ring down, causing the pull plates to move towards the center of the base plate under the action of the oblique T-slots. Use the fourth screw to press the cover plate firmly onto the base plate. Pass the third screw through the center hole of the cover plate and screw it into the centering ring. After screwing it into the correct position, use the second screw to press the retaining ring... Figure 5 The retaining ring is fixed to the cover plate in this manner (the third screw can rotate between the retaining ring and the cover plate). The three retaining blocks are placed in the appropriate positions of the three pull plates respectively, and fixed to the pull plates by the first screw and the first T-shaped block inserted into the inner T-slot of the pull plate.

[0018] When the third screw is rotated, the up-and-down movement of the centering ring, through the oblique T-shaped connection between the centering ring and the pull plate, causes the stop block to reciprocate, moving away from and towards the center.

[0019] Note that when installing the blocks, ensure that the distance from all three blocks to the center is equal.

[0020] (4) Double-cone angular positioning mechanism

[0021] The device includes a fixing device for a circular base plate indexing plate and a support plate. The circular base plate indexing plate and the support plate are evenly provided with tapered holes on their circumferences. The tapered part of the cylindrical tapered pin is inserted into the tapered hole of the support plate, so that the tapered surface of the cylindrical tapered pin and the tapered surface of the support plate are in contact. A washer is placed on the bottom surface, the 7th screw is inserted and tightened, and then the center hole of the magazine is inserted into the cylindrical part of the cylindrical tapered pin, and the nut and the 7th screw are tightened.

[0022] Beneficial Effects: This invention proposes a machining method for aero-engine support plate housings, using a dedicated self-centering fixture with a double-conical surface to eliminate positioning and repetitive positioning gaps. The newly proposed process and fixture design significantly reduce the machining cost of this type of housing. This double-conical surface orientation and self-centering fixture allows for rapid and stable workpiece clamping, saving labor, investment in expensive equipment, and programming costs. This invention can completely replace a five-axis machining center for machining support plate housings with appropriate fixtures. The positioning and indexing capabilities of the double-conical surface orientation self-centering fixture are particularly significant. The base plate 31 of the self-centering mechanism is aligned concentrically with the manual rotary table 23, ensuring that the workpiece 26 and the manual rotary table 23 are also concentric, guaranteeing machining accuracy. On a three-axis vertical machining center, machining the support plate housing using a single fixture offers superior accuracy and absolute speed compared to a five-axis machining center, while also being more efficient. Attached Figure Description

[0023] Figure 1 A schematic diagram of a finished workpiece awaiting processing;

[0024] Figure 2 This is a schematic diagram of the base structure;

[0025] Figure 3 This is a schematic diagram of the rotary mechanism.

[0026] Figure 4 The diagram shows a self-centering structure, in which the oblique T-slots 34 of the three pull plates 35 are aligned with the center of the base plate.

[0027] Figure 5 This is a schematic diagram of a double-cone angular positioning mechanism;

[0028] Figure 6 The image shown is a 3D diagram of the workpiece mounted on the tooling in this invention.

[0029] Figure 7 Schematic diagram of the centering ring structure.

[0030] Figure 8 : Schematic diagram of the structure on the pull plate; the pull plate is provided with inclined T-shaped groove rail 34-1, inner T-shaped groove 34-2, and outer T-shaped groove 34-3;

[0031] Figure 9 : Schematic diagram of the base plate structure. Detailed Implementation

[0032] Based on the schematic diagram of the workpiece and tooling, the process flow is designed as follows: To address the above issues, the process flow for machining the support plate casing is designed as follows: Rough turning of the casing's inner and outer shapes --- Rough milling of the casing's inner cavity and drilling of angular positioning holes --- Heat treatment --- Turning the datum --- Semi-finish turning of the exhaust side flow channel surface and outer surface --- Semi-finish turning of the inlet side flow channel surface and inner cavity --- Expanding the angular positioning holes --- Semi-finish milling of the exhaust side inner cavity --- Semi-finish milling of the inlet side inner cavity --- Turning the datum --- Finish turning of the exhaust side flow channel surface --- Finish turning of the inlet side flow channel surface --- Finish milling of the exhaust side inner cavity --- Finish milling of the inlet side inner cavity --- Finish milling of the inlet side inner cavity --- Finish turning of the exhaust side outer surface --- Finish turning of the inlet side inner cavity surface --- Drilling of the exhaust side mounting side holes --- Drilling of the inlet side mounting side holes --- Fitting and repair --- Fluorescent inspection --- Final inspection.

[0033] In this invention, rough turning is first used to quickly remove the excess material from the workpiece, so that the shape and inner cavity of the workpiece are quickly formed while meeting the requirements of the machining allowance. Then, the inner cavity and flow channel of the workpiece are rough machined on a three-axis vertical machining center. At this time, since the machining is performed on a three-axis machine tool, there is still a relatively large amount of excess material remaining in the inner and outer flow channels of the workpiece, especially at the junction of the support plate and the flow channel. However, this excess material has little impact on the deformation of the subsequent machined parts for the relatively thick support plate casing, so it is ignored here. After rough milling, stress relief heat treatment is performed directly. After stress relief heat treatment, the reference surface of the workpiece is polished, and then the exhaust side flow channel surface and outer surface are semi-finish turned. Then, the intake side flow channel surface and inner cavity are semi-finish turned. Thus, the semi-finish machining of the workpiece in the turning process is completed.

[0034] After completing the enlarging process of the locating pin hole on the vertical machining center, Figure 6 The tooling is mounted on a three-axis (805) machine tool. After the workpiece is installed as required, the semi-finish milling of the air outlet side cavity can begin. By rotating the handle of the manual turntable and cooperating with the double conical contact positioning pin, the machining of this side is completed. The same method can be used to complete the semi-finish milling of the air inlet side cavity. Thus, the semi-finish machining process of the entire part is completed. During this process, all the allowances left by rough milling are removed, so that the current workpiece shows that the allowances in all places are uniform and consistent, completing the preparation work for subsequent finishing.

[0035] After allowing the workpiece to rest in a free state for a period of time to release some stress, the workpiece's reference surface is re-polished. The portion of the outlet flow channel extending beyond the support plate is then precision-machined into place. The same process is used to precision-machine the portion of the inlet flow channel extending beyond the support plate. The workpiece is then mounted on the machine tool fixture and clamped. Note that the locating pin hole is not enlarged at this stage because the fixture uses a slider and locating pin positioning method. As long as the angular orientation of the positioning is correct, the change in the pitch circle of the locating pin hole due to part deformation has no actual impact on the machining process. Therefore, a second enlargement of the locating pin hole is not performed to simplify the process and improve efficiency.

[0036] After the workpiece is clamped, the inner cavity on the air outlet side will be machined. When using this fixture for finishing, the essence is to machine different areas of the surface in sections, then rotate the manual turntable and position it using a double-cone locating device, and then machine another section. This process is repeated until all surfaces are connected. Therefore, when writing the machining program, it is crucial to plan the machining area after each positioning (the planned machining area should be symmetrical to minimize workpiece deformation) to avoid omissions. Appropriate tool holders, cutting tools, tool lengths, and machining parameters should be used to minimize tool deflection and ensure machining accuracy. After completing this step, the workpiece can be flipped over, and the inner cavity on the air inlet side can be machined in the same way.

[0037] After the internal cavity is finished, the workpiece is left in a free state for a period of time before finish turning it. First, the outer surface of the exhaust side of the workpiece is finish turned into place. Then, the workpiece is flipped over, and the inner cavity surface of the intake side is finish turned. This completes the finish turning of the part.

[0038] After drilling the air-side mounting holes as required, the workpiece is flipped over and then clamped using a two-pin clamping method on one side to complete the machining of the air-side mounting holes. Next, it undergoes finishing to remove burrs, flash, etc., accumulated during machining. Finally, after passing a fluorescent inspection, it is sent to the final inspection department for a final inspection of all dimensions. Once qualified, it is put into storage. This completes the machining of the entire workpiece.

[0039] This process flow effectively increases workpiece turnover speed and efficiency by shortening the process route length. Simultaneously, the use of roughing, semi-finishing, and finishing methods effectively controls part deformation, ensures a high first-pass yield, and stabilizes product quality.

[0040] Tooling design: Based on the motion of the spindle head in a five-axis machining center machining the support plate housing, and according to its swing direction and angle, the following tooling was designed: Figure 6As shown, this is a tooling fixture capable of machining the support plate housing on a three-axis vertical machining center. This fixture features accurate positioning, error-free repeatable positioning, and automatic centering.

[0041] This fixture mainly consists of four parts: a base, a rotary mechanism, a self-centering mechanism, and a double-cone angular positioning mechanism.

[0042] (1) Base part

[0043] like Figure 2 The base section consists of a support plate fixed to a base with two included angles in two directions using the 6th screw and a locating pin. The angles of the base in these two directions need to be determined by comprehensively considering several factors, including the machine tool's stroke, the type of tool holder, the angles of the inner and outer flow channels, and the clearance angle.

[0044] (2) Rotary mechanism

[0045] like Figure 3 As shown, the rotary mechanism is achieved by fixing the base plate to the manual turntable via the second T-block using the fifth screw. The turntable can be rotated by turning the handle on the manual turntable to obtain different angles.

[0046] (3) Self-centering mechanism

[0047] like Figure 4 As shown, align the oblique T-slots 34 of the three pull plates 35 with the center of the base plate. Insert T-blocks into the corresponding T-slots on the base plate and push them towards the center to the appropriate position. Place the centering ring in the center hole of the base plate. Simultaneously adjust the head position of the oblique T-slots of the three pull plates so that all three pull plates are inserted into the corresponding oblique T-slots on the centering ring. Press the centering ring down, causing the pull plates to be continuously pressed into the center hole of the base plate by the oblique T-slots, making the pull plates move towards the center. Use the fourth screw to press the cover plate onto the base plate. Pass the third screw through the center hole of the cover plate and screw it into the centering ring. After screwing it into the appropriate position, use the second screw to press the retaining ring... Figure 5 The retaining ring is fixed to the cover plate in this manner (the third screw can rotate between the retaining ring and the cover plate). The three retaining blocks are placed in the appropriate positions of the three pull plates respectively, and fixed to the pull plates by the first screw and the first T-shaped block inserted into the inner T-slot of the pull plate.

[0048] When the third screw is rotated, the up-and-down movement of the centering ring, through the oblique T-shaped connection between the centering ring and the pull plate, causes the stop block to reciprocate, moving away from and towards the center.

[0049] Note that when installing the blocks, ensure that the distance from all three blocks to the center is equal.

[0050] (4) Double-cone angular positioning mechanism

[0051] like Figure 5 As shown, rotate the indexing ring to a suitable position so that its conical hole is basically concentric with the conical hole of the support plate (these two conical holes are the core components of the double-conical angular positioning mechanism). Insert the conical part of the cylindrical conical pin (this taper uses a 1:50 taper to reduce costs and improve positioning accuracy) into the conical hole of the support plate, so that the conical surface of the cylindrical conical pin and the conical surface of the support plate are in contact. Place a washer on the bottom surface, insert the 7th screw and tighten it. Then insert the center hole of the magazine (here an ER32 high-precision standard magazine) into the cylindrical part of the cylindrical conical pin and tighten the nut.

[0052] During the process of tightening the nut and pressing the magazine down, since the indexing ring is connected to the manual turntable via the base plate, when the handle of the manual turntable is released, the indexing ring has a certain degree of rotational freedom because there is a certain gap between the worm gear and the worm wheel of the manual turntable (this gap can be adjusted appropriately). When the nut is tightened, since the magazine is already fixed on the cylindrical conical pin on the support plate, the magazine only moves downward. When the conical surface of the magazine presses against the conical surface of the indexing ring, the indexing ring rotates slightly around the center, causing the conical surface of the magazine to fit into the conical surface of the indexing ring, thus bringing the indexing ring to the accurate position (at this time, the conical hole of the indexing ring and the conical hole of the support plate are exactly in the concentric position), thereby completing the double conical angular positioning process.

[0053] like Figure 6 The image shown is a 3D diagram of the workpiece mounted on the fixture in this invention. The components include: washer 18, base 15, cover plate 12, 4th screw 11, 5th screw 13, 6th screw 16, 7th screw 17, 3rd screw 8, retaining ring 9, centering ring 10, pull plate 6, 1st T-block 4, 1st screw 3, stop block 2, indexing ring 1, and 9th screw 30.

[0054] First, place the base in the appropriate position on the machine tool, then place the manual rotary table 23 into the base 15, using locating pins and screws (these locating pins and screws...). Figure 6 (Not shown above) Secure it to the base plate, place the support plate 5 on the base 15, and use the sixth screw 16 and the locating pin 36 (this locating pin) Figure 6(Not shown above) Secure it to the base plate 15. Use the fifth screw 13 and the second T-block 14 to fix the self-centering mechanism placed on the manual turntable 23 to the manual turntable 23, and align the self-centering mechanism and the manual turntable to be concentric. Rotate the third screw 8 to move the centering ring 10 upwards, moving the stop block 2 away from the center, and insert the slider 24 into the base plate 31 of the self-centering mechanism. Place the workpiece 26 on the base plate 31 of the self-centering mechanism and connect it to the slider 24 via the first positioning pin 25. Rotate the third screw 8 to move the centering ring 10 downwards, moving the stop block 2 closer to the center. When all three stop blocks 2 are in contact with the workpiece 26, tighten the third screw slightly. At this point, the workpiece and the base plate 31 of the self-centering mechanism are concentric. Since the base plate 31 of the self-centering mechanism and the manual turntable 23 have already been aligned for concentricity, the workpiece 26 to be processed is also concentric with the manual turntable 23. Use the pressure plate 27 and the eighth screw 28 to fix the workpiece on the base plate 31. The base plate and the support plate are two plates.

[0055] Use the 9th screw 30 and the 2nd locating pin 29 to install the indexing ring 1 of the double conical angular positioning mechanism on the base plate 31. Note that after this is installed, the indexing ring 1 and the manual turntable 23 are also concentric.

[0056] Rotate handle 22 to place the angular positioning hole of the workpiece in the correct position. Insert the tapered part of the cylindrical tapered pin into the tapered hole of the support plate, so that the tapered surface of the cylindrical tapered pin and the tapered surface of the support plate are in contact. Place a washer on the bottom surface, insert the 7th screw and tighten it. Then insert the magazine into the tapered hole of the indexing ring and tighten the nut. During the process of tightening the nut and pressing the magazine down, the indexing ring changes from a certain angle. When the nut is tightened, the indexing ring reaches the correct position, and the double-tapered angular positioning is completed.

[0057] Once the tooling and workpiece installation is complete, machining can begin. After machining is finished, loosen nut 21 and screw 7 17, remove clip 20 and cylindrical-conical pin 19, and crank handle 22 to the next suitable conical hole position. Repeat the previous actions to complete the next machining. By doing so, the machining of the inner and outer flow channels of the support plate casing and the support plate can be completed.

[0058] Figure 7 For centering ring; Figure 8 The pull plate is equipped with an inclined T-shaped groove rail 34-1, an inner T-shaped groove 34-2, and an outer T-shaped groove 34-3;

[0059] Figure 9The base plate is supported by a three-claw structure. The three-claw structure includes a circular base plate with three T-slots 34 evenly distributed on it. Each T-slot contains a pull plate, and the outer surface of the pull plate is a T-rail embedded in the T-slot. A T-slot is provided in the center of the pull plate along its length. The pull plate is positioned near the center of the circular base plate as an inclined T-rail. The center of the circular base plate has a stepped hole. A centering ring is installed on the outer diameter step of the stepped hole. The circumference of the centering ring has three slots corresponding to the positions of the inclined T-rails near the center of the circular base plate. Each slot has an inclined surface that matches the lower end of the inclined T-rail. It also features a slider groove 24-1; the centering ring aligns the oblique T-slot structure of the three pull plates with the center of the base plate. T-blocks are inserted into the corresponding T-slots on the base plate, pushing them towards the center to the appropriate position. The centering ring is placed in the center hole of the base plate, and the positions of the oblique T-slot heads of the three pull plates are adjusted so that all three pull plates are inserted into their corresponding oblique T-slots on the centering ring. The centering ring is pressed down, causing the pull plates to move towards the center of the base plate under the action of the oblique T-slots. The fourth screw is used to press the cover plate onto the base plate. The third screw is passed through the center hole of the cover plate and screwed into the centering ring. After being screwed into the appropriate position, the second screw is used to press the retaining ring... Figure 5 The retaining ring is fixed to the cover plate in this manner (the third screw can rotate between the retaining ring and the cover plate). The three retaining blocks are placed in the appropriate positions of the three pull plates respectively, and fixed to the pull plates by the first screw and the first T-shaped block inserted into the inner T-slot of the pull plate.

[0060] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for replacing five-axis machining of a support plate housing, characterized in that, Rough turning or milling the inner and outer rings of the support plate casing blank, semi-finish turning the inner and outer rings of the casing - semi-finish turning the exhaust side flow channel surface and outer surface, semi-finish turning the intake side flow channel surface and inner cavity, widening the positioning hole; semi-finish milling the exhaust side cavity, semi-finish milling the intake side inner cavity, finish milling the exhaust side inner cavity, and finish milling the intake side inner cavity on a special tooling. On a three-axis vertical machining center, rough milling is performed on the inner cavity and flow channel of the workpiece. The inner and outer flow channels of the workpiece, as well as the position where the support plate and the flow channel intersect, are left with a certain amount of allowance. The reference surface is polished, and the air outlet flow channel surface and outer surface are semi-finished. Then, the air inlet flow channel surface and inner cavity are semi-finished. This completes the semi-finishing of the workpiece in the turning process. After completing the enlargement of the positioning pin hole of the workpiece on the three-axis vertical machining center, the tooling is mounted on the three-axis machine tool. After the workpiece is installed, the semi-finish milling of the air outlet side cavity begins. By rotating the handle of the manual turntable and cooperating with the double conical surface contact positioning pin, the machining of the exposed side is completed. The same method is used to complete the semi-finish milling of the air inlet side cavity, completing the semi-finish machining process of the entire part and removing all the excess material left by rough milling. The reference surface is re-polished, and the flow channel portion extending beyond the support plate on the exhaust side of the workpiece is precision machined into place. The same method is used to precision machine the flow channel portion extending beyond the support plate on the intake side of the workpiece. The workpiece is then mounted and clamped on the machine tool fixture, which incorporates a sliding block and locating pin positioning structure. After clamping, one inner cavity area on the exhaust side of the workpiece is machined into place. Then, by rotating the manual turntable at a certain angle and positioning it with a double-cone surface locating device, another inner cavity area is machined. This process is repeated until all the inner cavities with support plate structures between the two rings are machined, connecting the curved surfaces of the inner cavities. The inner cavity on the intake side of the workpiece is machined in the same manner. After the precision milling of the inner cavity is completed, the workpiece is placed in a free state for a period of time, and then the workpiece is precision machined. First, the outer surface of the air outlet side of the workpiece is precision machined into place, and then the workpiece is turned over and the inner cavity surface of the air inlet side is precision machined; thus, the precision machining of the part is completed. After drilling the air-side mounting hole as required, turn the workpiece over and then use a clamping method with two pins on one side to complete the machining of the air-side mounting hole. The special tooling consists of four parts: a base (F), a rotary mechanism, a self-centering mechanism, and a double-cone angular positioning mechanism. The base part (F) is formed by fixing the support plate to the base with two directional angles using the 6th screw and the positioning pin; the rotation mechanism is fixed to the base support plate, and the rotation mechanism is formed by fixing the base plate to the manual turntable by the 5th screw through the 2nd T-block. The turntable is rotated by rotating the handle on the manual turntable to obtain different angles; the self-centering mechanism is fixed to the base plate above the manual turntable. The self-centering mechanism is a three-jaw structure for fixing the workpiece; the double conical angular positioning mechanism includes a fixing device for the circular base plate indexing plate and the support plate. The circular base plate indexing plate and the support plate are evenly provided with conical holes on their circumference. The conical part of the cylindrical conical pin is inserted into the conical hole of the support plate, so that the conical surface of the cylindrical conical pin and the conical surface of the support plate are in contact. A washer is placed on the bottom surface, the 7th screw is inserted and tightened, and then the center hole of the magazine is inserted into the cylindrical part of the cylindrical conical pin and the nut is tightened with the 7th screw; The three-jaw clamping structure includes a circular base plate indexing plate. Three T-slots are evenly distributed on the base plate, each containing a pull plate. The outer surface of the pull plate is a T-shaped rail embedded in the T-slot. A T-slot is located in the center of the pull plate along its length. Near the center of the circular base plate, an inclined T-shaped rail is positioned. A stepped hole is located in the center of the circular base plate. A centering ring is installed on the outer diameter step of the stepped hole. Three slots are located on the circumference of the centering ring corresponding to the positions of the inclined T-shaped rails near the center of the circular base plate. Each slot has an inclined surface that matches the lower end of the inclined T-shaped rail. The centering ring aligns the inclined T-slots of the three pull plates with the center of the base plate. T-blocks are inserted into the corresponding T-slots on the base plate and pushed towards the center to the appropriate position. The centering ring is then placed in the center hole of the base plate. Simultaneously, the positions of the inclined T-slot heads of the three pull plates are adjusted. All three pull plates are inserted into the corresponding oblique T-slots on the centering ring. Press the centering ring down, causing the pull plates to move towards the center of the base plate under the action of the oblique T-slots. Use the fourth screw to press the cover plate onto the base plate. Pass the third screw through the center hole of the cover plate and screw it into the centering ring. After screwing it into the appropriate position, use the second screw to fix the retaining ring onto the cover plate. The third screw rotates between the retaining ring and the cover plate. Place the three stop blocks in the appropriate positions on the three pull plates. Fix them onto the pull plates by the first screw and the first T-shaped block inserted into the inner T-slot of the pull plate. When the third screw is rotated, the up and down movement of the centering ring, through the oblique T-shaped connection between the centering ring and the pull plate, causes the stop blocks to reciprocate, moving away from and towards the center. When installing the stop blocks, ensure that the distance from the center of the three stop blocks is equal.

2. The method for replacing the five-axis machining support plate housing according to claim 1, characterized in that, Rotate the indexing ring to the appropriate position so that the tapered hole of the indexing ring is concentric with the tapered hole of the support plate. Insert the tapered part of the cylindrical tapered pin into the tapered hole of the support plate, using a 1:50 taper, so that the tapered surface of the cylindrical tapered pin fits against the tapered surface of the support plate. Place a washer on the bottom surface, insert the 7th screw and tighten it. Then insert the center hole of the magazine into the cylindrical part of the cylindrical tapered pin and tighten the nut. During the process of tightening the nut and pressing the magazine down, since the indexing ring is connected to the manual turntable through the base plate... When the handle of the manual turntable is released, the indexing ring has rotational freedom due to the gap between the worm gear and the worm wheel. When the nut is tightened, the magazine is fixed on the cylindrical-conical pin on the support plate, so the magazine only moves downward. When the conical surface of the magazine presses against the conical surface of the indexing ring, the indexing ring rotates angularly around the center, so that the conical surface of the magazine and the conical surface of the indexing ring are in contact, thus allowing the indexing ring to reach the accurate position; thus completing the double-conical angular positioning.

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