A method and fixture for grinding the inner circle of a moving blade guard ring

Abstract

The present invention relates to the technical field of impeller shroud processing technology, and provides a method and fixture for grinding the inner circle of an impeller shroud. The grinding method comprises the following steps: individually fixing the arc segments that make up the impeller shroud, so that all the arc segments form a circular ring structure that simulates the working state of the impeller shroud; then, using an inner circle grinding device, grinding the inner sides of all the arc segments. The present invention replaces the existing method of independently grinding individual arc segments with grinding the inner circle, thereby ensuring the consistency of the grinding of each arc segment and thus the overall inner circle roundness of the impeller shroud. Furthermore, all arc segments are ground simultaneously, which shortens the processing cycle.

Description

Technical Field

[0001] The present invention relates to the technical field of moving blade guard ring processing, and in particular to a method and a fixture for grinding the inner circle of a moving blade guard ring. Background Art

[0002] In aircraft engines, the blade guard ring is a key component installed on the periphery of the turbine blade. It mainly forms a closed flow channel by wrapping the blade tip area of the turbine blade, restricting the high-temperature and high-pressure airflow to flow along the designed path to reduce leakage. At the same time, it provides structural support for the turbine blade, resists the centrifugal force and airflow excitation force during high-speed rotation, and ensures the stability and safety of the blade operation.

[0003] In order to reduce the difficulty of processing, adapt to thermal expansion deformation, and reduce the impact of thermal stress on components, the rotor blade guard ring is usually designed as a segmented type, that is, a circular ring structure composed of several arc segments. In some rotor blade guard rings in the prior art, the structure of a single arc segment is as follows Figure 1 and Figure 2 As shown, the arc segment 1 includes an arc segment body and two rows of raised hook-shaped ears 101 arranged on the outside, including three ears 101 in the upper row and two ears 101 at each end of the lower row. The ends of the ears 101 and the arc segment body are rounded to form rounded corners 102.

[0004] In order to ensure normal working requirements, the inner side of each arc segment is usually polished to ensure the accuracy requirements. At present, the grinding of the moving blade guard ring is usually carried out by grinding the inner side of each arc segment separately. This method has a long processing cycle and it is difficult to ensure the grinding consistency of each arc segment. As a result, it is difficult to ensure the overall inner roundness of the moving blade guard ring after the arc segments are assembled into the moving blade guard ring. Summary of the Invention

[0005] The object of the present invention is to provide a method and fixture for grinding the inner circle of a moving blade guard ring, so as to solve the above-mentioned defects of the existing grinding method.

[0006] The present invention is achieved through the following technical solutions:

[0007] A method for grinding the inner circle of a moving blade guard ring is as follows: each arc segment constituting the moving blade guard ring is fixed separately, and all the arc segments are made to form a circular ring structure simulating the working state of the moving blade guard ring; and the inner sides of all the arc segments are ground by an inner circle grinding device.

[0008] The present invention also provides a fixture for grinding the inner circle of a moving blade guard ring, which is applied to the above-mentioned grinding method, and comprises an annular base, an annular positioning seat, and a fixing mechanism corresponding to each arc segment. The annular positioning seat is fixed to the top of the annular base and is used to support each arc segment and fit in a one-to-one correspondence with the outer side of the lower row of end hanging ears.

[0009] The fixing mechanism includes a fixing seat, an auxiliary positioning block, a tightening block, a tightening block and a circumferential fixing component. The fixing seat and the auxiliary positioning block are fixedly arranged, and the auxiliary positioning block is in contact with the outer side of the upper row middle hanging ear; the tightening block is connected to the fixing seat, and is used to tighten the lower row middle hanging ear outward; the tightening block is connected to the fixing seat, and is used to press the upper row middle hanging ear downward; the circumferential fixing component includes a positioning pin and a side tightening member provided on the annular positioning seat, the positioning pin cooperates with the rounded corner of one of the hanging ears in the lower row, and the side tightening member is used to tighten the other hanging ear in the lower row, and together with the positioning pin, it limits the circumferential position of the arc segment.

[0010] Optionally, the side tightening piece is in the shape of an elongated strip and is rotatably connected to the annular positioning seat via a pin. One end of the side tightening piece is provided with a tightening portion for contacting the hanging ear. The fixed seat is threadedly connected with a tightening screw for pushing the other end of the side tightening piece so that the tightening portion tightens the hanging ear.

[0011] Optionally, the tightening portion is a convex arc structure.

[0012] Optionally, one end of the tensioning block is provided with two tensioning parts, which are in one-to-one contact with the two middle hanging ears in the lower row. The tensioning block is slidingly connected to the fixed seat, and the other end of the tensioning block is rotatably connected to a tensioning screw, which is threadedly connected to the fixed seat.

[0013] Optionally, a through slot is provided on the fixing seat, the tensioning block is slidably engaged with the through slot, the outer end of the through slot is fixedly connected to a support seat, and the tensioning screw is threadedly connected to the support seat.

[0014] Optionally, the tensioning portion is a convex arc structure.

[0015] Optionally, a limiting groove is provided on the top of the fixing seat, and the clamping block is arranged in the limiting groove. A supporting top is provided at one end of the clamping block and contacts the bottom of the limiting groove. The supporting top is a circular arc convex structure, and a clamping surface is provided at the other end of the clamping block; a waist-shaped through hole extending along its length direction is provided in the middle of the clamping block, and the clamping block is connected to the bottom of the limiting groove by a locking screw passing through the waist-shaped through hole.

[0016] Optionally, the top of one end of the pressing block provided with the pressing surface is connected to a pressing screw via a thread, and the pressing screw is arranged obliquely to press the middle hanging ears in the upper row obliquely outward.

[0017] Optionally, the annular positioning seat is provided with a supporting positioning structure having the same number as the arc segments, and the supporting positioning structure includes two supporting positioning blocks, and the supporting positioning blocks are provided with supporting steps. The bottom of the supporting steps is used to support the arc segments, and the side surfaces of the supporting steps are used to fit with the outer side of the hanging ear.

[0018] The technical solution of the present invention has at least the following advantages and beneficial effects: In the present invention, the arc segments that make up the moving blade guard ring are fixed separately, and all the arc segments form a circular ring structure that simulates the working state of the moving blade guard ring, and then the inner sides of all the arc segments are polished by inner circle polishing equipment, that is, the existing method of independently polishing a single arc segment is converted into grinding the inner circle, which is convenient for ensuring the grinding consistency of each arc segment, thereby ensuring the overall inner circle roundness of the moving blade guard ring, and all the arc segments are polished at the same time, which is convenient for shortening the processing cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the arc segment structure of a rotor blade guard ring in the prior art Figure 1 ;

[0020] Figure 2 Schematic diagram of the arc segment structure of a rotor blade guard ring in the prior art Figure 2 ;

[0021] Figure 3 A diagram showing the use of a fixture for grinding the inner circle of a moving blade guard ring provided by the present invention;

[0022] Figure 4 It is a structural diagram of the annular chassis and the annular positioning seat;

[0023] Figure 5 It is a structural diagram of a single fixing mechanism in use;

[0024] Figure 6 The main view of a single fixing mechanism in use;

[0025] Figure 7 for Figure 6 AA section view in;

[0026] Figure 8 for Figure 6 BB cross-sectional view in;

[0027] Figure 9 A top view of a single fixing mechanism in use;

[0028] Figure 10 for Figure 9 The CC section view in the figure;

[0029] Figure 11 It is a structural diagram of the tensioning block;

[0030] Figure 12 Schematic diagram of the structure of the compression block;

[0031] Figure 13 It is a structural diagram of the side tightening member;

[0032] Figure markings: 1-arc segment, 101-hanging ear, 102-rounded corner, 2-annular chassis, 3-annular positioning seat, 301-support positioning block, 4-fixed seat, 5-auxiliary positioning block, 6-tensioning block, 601-tensioning part, 7-pressure block, 701-support top, 702-waist-shaped through hole, 8-positioning pin, 9-side tightening member, 901-tightening part, 10-tightening screw, 11-tensioning screw, 12-pressure screw, 13-support seat. DETAILED DESCRIPTION

[0033] A method for grinding the inner circle of a moving blade shroud is disclosed. The method comprises: fixing the individual arc segments 1 that make up the moving blade shroud separately, forming a circular ring structure that simulates the working state of the moving blade shroud; and then grinding the inner sides of all the arc segments 1 using an inner circle grinding device. This method replaces the existing method of independently grinding individual arc segments 1 with grinding the inner circle, thereby ensuring the consistency of the grinding of each arc segment 1 and thus the overall inner circle roundness of the moving blade shroud. Furthermore, all arc segments 1 are ground simultaneously, shortening the processing cycle.

[0034] refer to Figure 2-Figure 5 The present invention also provides a fixture for grinding the inner circle of the moving blade guard ring, which is applied to the above-mentioned grinding method, that is, it is used to fix each arc segment 1 separately and make all the arc segments 1 form a circular ring structure that simulates the working state of the moving blade guard ring.

[0035] The polishing fixture includes an annular base 2, an annular locating seat 3, and a fixing mechanism corresponding to each arc segment 1. The annular locating seat 3 is fixed to the top of the annular base 2. Specifically, the annular locating seat 3 is connected to the annular base 2 by screws. In actual use, the relative position of the two is maintained by cylindrical pins. The annular locating seat 3 is used to support each arc segment 1 and aligns with the outer side of the lower row of end lugs 101. In other words, after the annular locating seat 3 initially positions each arc segment 1, the fixing mechanism accurately positions and fixes each arc segment 1.

[0036] In this embodiment, the annular positioning seat 3 is provided with support positioning structures having the same number as the arc segments 1, and each arc segment 1 is placed at a corresponding support positioning structure. Figure 3 and Figure 5 The support and positioning structure includes two support and positioning blocks 301. The support and positioning blocks 301 are provided with support steps. The bottom of the support steps is used to support the arc segment 1, and the side of the support steps is used to fit with the outer side of the hanging ear 101. It is easy to understand that the side of the support step is designed to imitate the outer side of the hanging ear 101.

[0037] refer to Figure 5The fixing mechanism includes a fixing seat 4, an auxiliary positioning block 5, a tensioning block 6, a pressing block 7 and a circumferential fixing component. The fixing seat 4 and the auxiliary positioning block 5 are fixed. Specifically, the fixing seat 4 is connected and fixed to the annular chassis 2 by screws, and the auxiliary positioning block 5 is connected and fixed to the annular positioning seat 3 by screws. In actual application, the relative position between the auxiliary positioning block 5 and the annular positioning seat 3 is ensured by a cylindrical pin.

[0038] refer to Figure 9 and Figure 10 The auxiliary positioning block 5 is fitted with the outer side of the upper middle hanging ear 101. Similarly, the surface of the auxiliary positioning block 5 contacting the hanging ear 101 is designed to be contoured. The auxiliary positioning block 5 and the supporting positioning structure work together to achieve the preliminary positioning of each arc segment 1.

[0039] refer to Figure 6 、 Figure 7 and Figure 13 The circumferential fixing component includes a positioning pin 8 and a side tightening member 9 provided on the annular positioning seat 3. The positioning pin 8 cooperates with the rounded corner 102 of one of the lower row of hanging ears 101. The side tightening member 9 is used to tighten the other hanging ear 101 in the lower row and jointly limit the circumferential position of the arc segment 1 with the positioning pin 8. Preferably, the positioning pin 8 and the side tightening member 9 are respectively provided at two mutually symmetrical hanging ears 101 in the lower row. As an option, the side tightening member 9 is in the shape of an elongated strip and is rotatably connected to the annular positioning seat 3 through a latch. One end of the side tightening member 9 is provided with a tightening portion 901 for contacting the hanging ear 101. A tightening screw 10 is threadedly connected to the fixing seat 4. By turning the tightening screw 10, it can push the other end of the side tightening member 9 (i.e., the end away from the tightening portion 901), even if the side tightening member 9 rotates around the latch, so that the tightening portion 901 presses against the hanging ear 101. Furthermore, the tightening portion 901 is a raised arc structure, so that the contact surface with the lug 101 is linear contact, ensuring that the lug 101 can be tightened by rotating the side tightening member 9. It should be understood that in other embodiments, the side tightening member 9 can of course also have other structures, for example, the side tightening member 9 can also be a cylindrical pin like the positioning pin 8. After the arc segment 1 is initially positioned, the positioning pin 8 and the cylindrical pin are installed to jointly achieve circumferential positioning of the arc segment 1.

[0040] refer to Figure 6 、 Figure 8 and Figure 11The tensioning block 6 is connected to the fixing seat 4 and is used to tighten the lower row of middle hanging ears 101 outward. That is, the radial position of each arc segment 1 is fixed through the combined action of the tensioning block 6, the above-mentioned support positioning mechanism, and the above-mentioned auxiliary positioning block 5. In this embodiment, one end of the tensioning block 6 is provided with two tensioning portions 601, and the two tensioning portions 601 are in one-to-one contact with the two middle hanging ears 101 in the lower row. The tensioning block 6 is slidably connected to the fixing seat 4, and the other end of the tensioning block 6 is rotatably connected to a tensioning screw 11, which is threadedly connected to the fixing seat 4. In actual application, the tensioning block 6 is generally U-shaped. The tensioning portion 601 is provided at the open end of the U-shaped structure, and the tensioning screw 11 is rotatably connected to the closed end of the U-shaped mechanism. By turning the tensioning screw 11, the tensioning block 6 can be driven to move along the slide groove, thereby tightening the hanging ears 101 outward. Preferably, the tightening portion 601 is in a convex arc structure, so that the contact between the tightening portion 601 and the lug 101 is linear, thereby avoiding the tightening effect being affected by processing errors.

[0041] In order to facilitate the rotation of the tensioning screw 11, a handle is provided at the outer end of the tensioning screw 11. There is no restriction on the manner in which the tensioning screw 11 is rotationally connected to the tensioning block 6. For example, in this embodiment, a T-slot is provided on the tensioning block 6, and the end of the tensioning screw 11 is designed as a T-shaped head that cooperates with the T-slot. In other embodiments, the manner in which the tensioning screw 11 is rotationally connected to the tensioning block 6 may of course also be other manners, for example, the tensioning screw 11 and the tensioning block 6 are connected via a bearing. There is no restriction on the manner in which the tensioning block 6 is slidably connected to the fixed seat 4. For example, in this embodiment, a through groove is provided on the fixed seat 4, the tensioning block 6 slidably cooperates with the through groove, the outer end of the through groove is fixedly connected (preferably connected by screws) to the support seat 13, and the tensioning screw 11 is threadedly connected to the support seat 13.

[0042] refer to Figure 5 、 Figure 10 and Figure 12 , the clamping block 7 is connected to the fixing seat 4 and is used to press the upper row of middle hanging ears 101 downward to fix the axial position of each arc segment 1. Specifically, the connection method of the clamping block 7 and the fixing seat 4 is as follows: a limiting groove is provided at the top of the fixing seat 4, and the clamping block 7 is arranged in the limiting groove. One end of the clamping block 7 is provided with a supporting top 701 that contacts the bottom of the limiting groove. The supporting top 701 is a circular arc convex structure, and the other end of the clamping block 7 is provided with a clamping surface; the middle part of the clamping block 7 is provided with a waist-shaped through hole 702 extending along its length direction, and the clamping block 7 is connected to the bottom of the limiting groove by a locking screw passing through the waist-shaped through hole 702. It is worth noting that since the supporting top 701 is a circular arc convex structure, the contact between the supporting top 701 and the bottom of the limiting groove is line contact, which can allow the end of the clamping block 7 with the clamping surface to rotate around the supporting top 701, so that after tightening the locking screw, it can ensure that the clamping surface presses the upper row of middle hanging ears 101 downward.

[0043] Furthermore, the top of one end of the clamping block 7, which is provided with a clamping surface, is threadedly connected to a clamping screw 12. The clamping screw 12 is arranged at an angle to compress the upper middle hanging ears 101 in an oblique outward direction. It is easy to understand that the clamping screw 12 presses on the inner side of the hook portion of the hanging ear 101, exerting downward and outward force thereon, thereby assisting in compressing and tightening each arc segment 1. It is worth noting that since the hole for mounting the locking screw on the clamping block 7 is a waist-shaped through hole 702 extending along its length, this arrangement facilitates adjustment of the radial position of the clamping block 7 in the arc segment 1, avoiding the failure of the clamping screw 12 to tighten due to processing errors.

[0044] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A fixture for grinding the inner circle of a moving blade shroud, employing the following grinding method: fixing the arc segments that make up the moving blade shroud separately, and making all the arc segments form a circular ring structure that simulates the working state of the moving blade shroud; then grinding the inner sides of all the arc segments using an inner circle grinding device; characterized in that: The grinding fixture includes an annular chassis, an annular positioning seat, and a fixing mechanism corresponding to each arc segment. The annular positioning seat is fixed on the top of the annular chassis and is used to support each arc segment and fit in a one-to-one correspondence with the outer side of the lower row of end hanging ears. The fixing mechanism includes a fixing seat, an auxiliary positioning block, a tightening block, a tightening block and a circumferential fixing component. The fixing seat and the auxiliary positioning block are fixedly arranged, and the auxiliary positioning block is in contact with the outer side of the upper row middle hanging ear; the tightening block is connected to the fixing seat, and is used to tighten the lower row middle hanging ear outward; the tightening block is connected to the fixing seat, and is used to press the upper row middle hanging ear downward; the circumferential fixing component includes a positioning pin and a side tightening member provided on the annular positioning seat, the positioning pin cooperates with the rounded corner of one of the hanging ears in the lower row, and the side tightening member is used to tighten the other hanging ear in the lower row, and together with the positioning pin, it limits the circumferential position of the arc segment.

2. The inner grinding fixture for the rotor blade shroud according to claim 1 is characterized in that: The side tightening piece is in the shape of an elongated strip and is rotatably connected to the annular positioning seat through a pin. One end of the side tightening piece is provided with a tightening portion for contacting the hanging ear. The fixing seat is threadedly connected with a tightening screw for pushing the other end of the side tightening piece so that the tightening portion tightens the hanging ear.

3. The inner grinding fixture for the rotor blade shroud according to claim 2 is characterized in that: The tightening portion is in a convex arc structure.

4. The inner grinding fixture for the rotor blade shroud according to claim 1 is characterized in that: One end of the tensioning block is provided with two tensioning parts, which are in one-to-one contact with the two middle hanging ears in the lower row. The tensioning block is slidably connected to the fixed seat, and the other end of the tensioning block is rotatably connected to a tensioning screw, which is threadedly connected to the fixed seat.

5. The inner grinding fixture for the rotor blade shroud according to claim 4 is characterized in that: The fixing seat is provided with a through sliding groove, the tensioning block is slidably matched with the through sliding groove, the outer end of the through sliding groove is fixedly connected to the support seat, and the tensioning screw is connected to the support seat through a thread.

6. The inner grinding fixture for the rotor blade shroud according to claim 4 is characterized in that: The tensioning portion is in a convex arc structure.

7. The inner grinding fixture for the rotor blade shroud according to claim 1 is characterized in that: A limiting groove is provided on the top of the fixing seat, and the clamping block is arranged in the limiting groove. A supporting top is provided at one end of the clamping block, which contacts the bottom of the limiting groove. The supporting top is a circular arc convex structure, and a clamping surface is provided at the other end of the clamping block; a waist-shaped through hole extending along its length is provided in the middle of the clamping block, and the clamping block is connected to the bottom of the limiting groove by a locking screw passing through the waist-shaped through hole.

8. The inner grinding fixture for the rotor blade shroud according to claim 7 is characterized in that: The top of one end of the pressing block provided with a pressing surface is connected to a pressing screw through a thread, and the pressing screw is arranged obliquely to press the middle hanging ears in the upper row toward the oblique outward direction.

9. The inner grinding fixture for the rotor blade shroud according to claim 1, characterized in that: The annular positioning seat is provided with a supporting positioning structure having the same number as the arc segments, and the supporting positioning structure includes two supporting positioning blocks. The supporting positioning blocks are provided with supporting steps. The bottom of the supporting steps is used to support the arc segments, and the side surfaces of the supporting steps are used to fit with the outer sides of the hanging ears.

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