A boring module fixing tool and method for machining a rotating part coupling hole of a hydroelectric generating set

Abstract

The application provides a boring die fixing tool and method for machining a rotating part coupling hole of a hydroelectric generator set, and relates to the technical field of machining. The tool and method solve the problems of inaccurate positioning, low efficiency and high cost of the boring die and the rotating part in the machining process of the coupling hole. The tool comprises a first plug, a second plug, a first bidirectional screw rod and a pair of first nuts. The first plug and the second plug are both provided with a central through hole with a diameter larger than that of the first bidirectional screw rod. The first bidirectional screw rod is arranged in the central through hole. The pair of first nuts are located at the two ends of the first plug and the second plug and are threadedly connected with the first bidirectional screw rod. The first plug comprises a first cylindrical part and a first circular table part which are axially connected. The second plug comprises a second cylindrical part and a second circular table part which are axially connected. The first cylindrical part is coaxially inserted and matched with the second cylindrical part. The tool is mainly used for improving the machining speed and efficiency of the rotating part coupling hole of the hydroelectric generator set and reducing the cost.

Description

Technical Field

[0001] This invention relates to the field of machining technology, and in particular to a boring die fixing fixture and method for machining the connecting holes of rotating components of hydroelectric generators. Background Technology

[0002] Rotating components are the core components of a hydroelectric generator set. These components mainly include the turbine main shaft, generator main shaft, and runner. The turbine main shaft and runner, and the turbine main shaft and generator main shaft, are connected by mounting and positioning pins. The connection holes of the two corresponding rotating components are machined using the same boring die. The current method involves first pre-machining through holes (with a diameter smaller than the target connection hole diameter) on the blank of the rotating component. Then, fixing components are installed at half of the through holes and their corresponding boring die positioning holes to connect and fix the boring die to the blank. The through holes on the blank without fixing components are machined into connection holes. The diameters of two machined connection holes and their corresponding boring die positioning holes are measured. Positioning pins are machined according to the measured diameters and installed in the two connection holes and their corresponding boring die positioning holes. A set of fixing components between the boring die and the blank is removed and inserted into one of the machined connection holes and its corresponding boring die positioning hole for repositioning. Repeat the above process of disassembling and assembling the fixing components, installing the fixing components into the other pre-machined connecting holes except for the locating pins. Then, machine the remaining through holes into connecting holes. Currently, except for the two connecting holes with locating pins, all other pre-machined connecting holes require the installation of connecting components, resulting in a large workload, high cost, and low efficiency. Before the locating pins are machined, the connecting hole machining equipment needs to be stopped, occupying the equipment for a long time, leading to low production efficiency and high cost. The process is labor-intensive, time-consuming, and inefficient.

[0003] Furthermore, in order to ensure that the locating pin can be installed in the connecting hole and the boring die locating hole, the locating pin needs to have a clearance fit with the connecting hole and the boring die locating hole. During the process of removing the fixing component and installing it into the machined connecting hole, there is a risk that the boring die may move relative to the blank. This results in the subsequent machined connecting hole and the machined connecting hole not forming a uniform circumferential distribution, and the relative position between the connecting holes does not meet the requirements, leading to the problem that the two corresponding rotating parts cannot be correctly positioned and assembled.

[0004] Furthermore, since the dimensions of the locating pins are machined based on the actual measured dimensions of specific holes, the locating pins are not universal, resulting in the need to manufacture locating pins for different rotating parts in the same project, which increases manufacturing costs. Summary of the Invention

[0005] The present invention aims to provide a boring die fixing fixture and method for machining connecting holes of rotating components of hydropower units, so as to solve the problems of inaccurate positioning of the boring die and the rotating component, low efficiency and high cost in the existing connecting hole machining process.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a boring die fixing fixture for machining the connecting hole of the rotating component of a hydropower unit, comprising a first plug, a second plug, a first bidirectional screw, and a pair of first nuts. The first plug and the second plug are each provided with a central through hole with a diameter larger than that of the first bidirectional screw. The first bidirectional screw passes through the central through hole. The pair of first nuts are located at both ends of the first plug and the second plug and are threadedly connected to the first bidirectional screw, for pushing the first plug and the second plug closer to each other. The first plug includes a first cylindrical portion and a first frustum portion connected axially, and the second plug includes a second cylindrical portion and a second frustum portion connected axially, with the first cylindrical portion and the second cylindrical portion being coaxially inserted into each other.

[0007] Furthermore, the end faces of the first plug and the second plug that are separated from each other are respectively provided with a first central countersunk hole and a second central countersunk hole, and the pair of first nuts are respectively connected to the bottom surfaces of the first central countersunk hole and the second central countersunk hole.

[0008] A method for machining connecting holes in a rotating component of a hydroelectric generator set, wherein the rotating component is uniformly provided with 2N connecting holes in its circumference, where N is an integer ≥2, the diameter of the connecting holes is D, and a first recessed stop is provided on one end face of the rotating component; Specifically, the following steps are included: S1. Raw material and tool preparation: Prepare the blank, select one end face as the end face to be processed, and coaxially process the first concave stop on the end face to be processed. The first concave stop is a cylindrical groove. Prepare a boring die. The boring die is uniformly provided with 2N positioning through holes in the circumference, and one end face is provided with a first convex stop that matches the first concave stop. Prepare 2X fixing components and 2Y fixing fixtures for the boring die for processing the connecting hole of the rotating component of the hydroelectric generator. The fixing components include a second bidirectional screw, a pair of washers passing through the second bidirectional screw, and a pair of second nuts threadedly connected to the second bidirectional screw. X and Y are both integers ≥1, and X+Y≤N. S2. First-time machining of connecting holes: On the end face to be machined, 2N first through holes are initially machined, the diameter of the first through holes being d, where d... <D; S3. Fixing the boring die at one time: First, use the first concave stop and the first convex stop to assemble the boring die coaxially with the end face to be processed. Then, rotate the boring die so that the positioning through hole is opposite to the first through hole. Select 2X sets of positioning through holes and the first through hole to install and fix the components, and tighten a pair of second nuts until a pair of washers are connected to a pair of end faces that are separate from the positioning through hole and the first through hole, thus fixing the boring die to the end face to be processed. S4. Secondary machining of connecting holes: Based on the positioning through hole, the unselected first through hole is machined into the first target through hole, and the diameter of the first target through hole is D. S5. Secondary fixing of the boring die: Select the first target through hole and the positioning through hole of the 2Y group to install the boring die fixing fixture for machining the connecting hole of the rotating part of the hydropower unit, and tighten a pair of first nuts until the outer wall of the first truncated cone part is connected to the opening of the first target through hole and the outer wall of the second cylindrical part is connected to the opening of the positioning through hole. Fix the first target through hole and the positioning through hole coaxially, and then remove the fixing assembly. S6. Three-stage machining of connecting holes: Using the positioning through hole as a reference, the remaining first through hole is machined into the first target through hole, completing the machining of all connecting holes of the rotating components of the hydroelectric generator. Furthermore, the length of the first cylindrical portion is greater than the length of the second cylindrical portion; The diameter of the first bidirectional screw is smaller than the inner diameter of the first cylindrical section; the outer diameter of the first cylindrical section is equal to the inner diameter of the second cylindrical section, and the outer diameter of the second cylindrical section is smaller than D; The diameter of the positioning through hole is R. 定 Satisfying: R 定 >D; The small end diameter of the first frustum is R1, and the large end diameter is R2, satisfying: R1 <D<R2; The smaller end diameter of the second frustum is R3, and the larger end diameter is R4, satisfying: R3 <R 定 <R4。

[0009] Furthermore, the length of the first plug is L1, the length of the second plug is L2, and the length of the first cylindrical portion is... l 1. The length of the second cylindrical section is l 2. The length of the first through hole is H1, and the length of the positioning through hole is H2, satisfying: l 1+ l 2

[0010] Furthermore, L1 = 1.6H1; L2 = 1.1H1; l 1 = 0.9H1; l 2=0.55H1; H2=0.5H1.

[0011] Furthermore, N=8, X=Y=2.

[0012] Furthermore, d = 0.9D.

[0013] Compared with the prior art, the beneficial effects of the boring die fixing fixture and method for machining the connecting hole of the rotating component of a hydroelectric generator described in this invention are: ​1. This invention utilizes a coaxially inserted first plug and a second plug as coaxial references to coaxially fix the first target through hole and the positioning through hole, thereby achieving the positioning connection between the blank and the boring die. Then, the first through hole used for fixing is machined. This invention achieves the positioning connection between the blank and the boring die using at least one pair of machined first target through holes on the blank and positioning through holes on the boring die. Compared to the original method of using half the number of connecting holes, this reduces workload, improves efficiency, and lowers costs.

[0014] 2. The present invention fastens a pair of first nuts to connect the outer wall of the first truncated cone portion to the opening of the first target through hole, and the outer wall of the second cylindrical portion to the opening of the positioning through hole. This clearance-free fit ensures that the first target through hole and the positioning through hole are reliably fixed, thereby ensuring that the blank and the boring die are reliably fixed, avoiding instability of the boring die reference, which would cause circumferential position deviation of the machined first target through hole.

[0015] 3. The present invention can eliminate the need for machining positioning pins during the machining of connecting holes, saving machining time. Furthermore, the outer wall of the first frustum and the outer wall of the second cylindrical part can be used to coaxially fix the first target through holes and positioning through holes of different diameters, thus having a certain degree of versatility. Attached Figure Description

[0016] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the structure of a boring die fixing fixture for machining the connecting hole of a rotating component of a hydroelectric generator, as described in this invention. Figure 2 This is a schematic diagram of the structure of the first plug of the present invention; Figure 3 This is a schematic diagram of the structure of the second plug of the present invention; Figure 4 This is a schematic diagram of the boring die described in this invention; Figure 5 This is a schematic diagram of the structure of the fixing component described in this invention; Figure 6 This is a schematic diagram of the structure when the boring die and the blank are fixed according to the present invention; Figure 7 For the present invention Figure 6 A sectional view along line A in the middle; Figure 8 For the present invention Figure 6 Sectional view along line B; Figure 9 For the present invention Figure 8 A magnified view of a section at point C; Figure 10 For the present invention Figure 8 Exploded view; In the diagram: 1. First plug; 2. Second plug; 3. First double-acting screw; 4. First nut; 11. First cylindrical section; 12. First frustum section; 13. First countersunk hole; 21. Second cylindrical section; 22. First frustum section; 23. Second countersunk hole; 1-1, First through hole; 1-2, First concave stop; 1-3, First target through hole; 2-1, Positioning through hole; 2-2, First convex stop; 3-1, Second bidirectional screw; 3-2, Washer; 3-3, Second nut; D is the diameter of the first target through hole; R 定 R1 and R2 are the diameters of the small and large ends of the first frustum, respectively; R3 and R4 are the small and large ends of the second frustum, respectively. L1 is the length of the first plug; L2 is the length of the second plug; l 1 represents the length of the first cylindrical section; l 2 is the length of the second cylindrical section; H1 is the length of the first through hole; H2 is the length of the second through hole. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other, and the described embodiments are only some embodiments of the present invention, not all embodiments.

[0018] Example 1, see Figure 1-3 This embodiment describes a boring tool for machining the connecting hole of a rotating component of a hydroelectric generator set, comprising a first plug 1, a second plug 2, a first bidirectional screw 3, and a pair of first nuts 4. Both the first plug 1 and the second plug 2 have a central through hole with a diameter larger than that of the first bidirectional screw 3. The first bidirectional screw 3 passes through the central through hole. The pair of first nuts 4 are located at both ends of the first plug 1 and the second plug 2 and are threadedly connected to the first bidirectional screw 3, used to push the first plug 1 and the second plug 2 closer together. The first plug 1 includes a first cylindrical portion 11 and a first frustum portion 12 connected axially. The second plug 2 includes a second cylindrical portion 21 and a second frustum portion 22 connected axially. The first cylindrical portion 11 and the second cylindrical portion 21 are coaxially inserted and fitted. The small ends of the first frustum portion 12 and the second frustum portion 22 are opposite to each other. The taper of the small end and the large end of the first frustum portion 12 and the small end and the large end of the second frustum portion 22 is 1:50.

[0019] The first plug 1 and the second plug 2 have a first central countersunk hole 13 and a second central countersunk hole 23 respectively on their opposite ends. The pair of first nuts 4 are respectively connected to the bottom surfaces of the first central countersunk hole 13 and the second central countersunk hole 23.

[0020] Example 2, see Figure 4-10 This embodiment describes a method for processing connecting holes in a rotating component of a hydroelectric generator set. The rotating component is provided with 16 connecting holes evenly distributed around its circumference. The diameter of each connecting hole is D. A first recessed stop 1-2 is provided on one end face of the rotating component. Specifically, the following steps are included: S1. Raw material and tool preparation: Prepare the blank, select one end face as the end face to be processed, and coaxially process the first concave stop 1-2 on the end face to be processed. The first concave stop 1-2 is a cylindrical groove. Prepare a boring die according to the size specifications of the rotating part. The boring die is evenly provided with 16 positioning through holes 2-1 around its circumference, and one end face is provided with a first convex stop 2-2 that cooperates with the first concave stop 1-2. The distribution circle diameter of the positioning through holes 2-1 is equal to the distribution circle diameter of the connecting hole. Prepare 4 fixing components and 4 fixing fixtures for the boring die for machining the connecting hole of the rotating part of the hydroelectric generator. The fixing components include a second bidirectional screw 3-1, a pair of washers 3-2 passing through the second bidirectional screw 3-1, and a pair of second nuts 3-3 threadedly connected to the second bidirectional screw 3-1. S2. First-time machining of connecting holes: On the end face to be machined, 2N first through holes 1-1 are initially machined, and the diameter of the first through hole 1-1 is 0.9D; S3. First fixation of the boring die: First, use the first concave stop 1-2 and the first convex stop 2-2 to assemble the boring die coaxially with the end face to be processed. Then, rotate the boring die so that the positioning through hole 2-1 is opposite to the first through hole 1-1. Select four sets of positioning through holes 2-1 with a circumferential interval of 90° to install the fixing components with the first through hole 1-1, and tighten a pair of second nuts 3-3 until a pair of washers 3-2 are connected to a pair of end faces of the positioning through hole 2-1 and the first through hole 1-1 that are separated, thus fixing the boring die with the end face to be processed. S4. Secondary machining of connecting holes: Taking the positioning through hole 2-1 as the reference, the remaining 12 unselected first through holes 1-1 are machined into first target through holes 1-3, and the diameter of the first target through hole 1-3 is D. S5. Secondary fixing of the boring die: Select four sets of first target through holes 1-3 and positioning through holes 2-1 with a circumferential interval of 90° to install the boring die fixing fixture for machining the connecting hole of the rotating component of the hydropower unit, and tighten a pair of first nuts 4 until the outer wall of the first truncated cone 12 is connected to the opening of the first target through hole 1-3 and the outer wall of the second cylindrical part 21 is connected to the opening of the positioning through hole 2-1. Fix the first target through hole 1-3 and the positioning through hole 2-1 coaxially, and then remove the four fixing components. S6. Three-stage machining of connecting holes: Taking the positioning through hole 2-1 as the reference, the remaining 4 first through holes 1-1 are machined into the first target through holes 1-3, thus completing the machining of all connecting holes of the rotating parts of the hydropower unit.

[0021] The length of the first cylindrical portion 11 is greater than the length of the second cylindrical portion 21; The diameter of the first bidirectional screw 3 is smaller than the inner diameter of the first cylindrical portion 11; the outer diameter of the first cylindrical portion 11 is equal to the inner diameter of the second cylindrical portion 21, and the outer diameter of the second cylindrical portion 21 is smaller than D. The diameter of the positioning through hole 2-1 is R. 定 Satisfying: R 定 >D; The diameter of the small end of the first frustum 12 is R1, and the diameter of the large end is R2, satisfying: R1 <D<R2; The smaller end diameter of the second frustum portion 22 is R3, and the larger end diameter is R4, satisfying: R3 <R 定 <R4。

[0022] The length of the first plug 1 is L1, the length of the second plug 2 is L2, and the length of the first cylindrical portion 11 is L1. l 1. The length of the second cylindrical section 21 is l 2. The length of the first through hole 1-1 is H1, and the length of the positioning through hole 2-1 is H2, satisfying: l 1+ l 2

[0023] The first nut 4 and the second nut 3-3 are both made of 45# steel and have undergone quenching and tempering treatment.

[0024] The radial distance between the first bidirectional screw 3 and the first cylindrical portion 11 is 1 mm; the radial distance between the second cylindrical portion 21 and the first target through hole 1-3 is 1 mm.

[0025] The embodiments of the present invention disclosed above are merely illustrative of the invention. These embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.​

Claims

1. A boring die fixing fixture for machining the connecting hole of a rotating component of a hydroelectric generator, characterized in that, It includes a first plug (1), a second plug (2), a first bidirectional screw (3), and a pair of first nuts (4). The first plug (1) and the second plug (2) are each provided with a central through hole with a diameter larger than that of the first bidirectional screw (3). The first bidirectional screw (3) passes through the central through hole. The pair of first nuts (4) are located at both ends of the first plug (1) and the second plug (2) and are threadedly connected to the first bidirectional screw (3) to push the first plug (1) and the second plug (2) closer to each other. The first plug (1) includes a first cylindrical part (11) and a first frustum part (12) connected axially, and the second plug (2) includes a second cylindrical part (21) and a second frustum part (22) connected axially, and the first cylindrical part (11) and the second cylindrical part (21) are coaxially inserted into each other.

2. The boring die fixing fixture for machining the connecting hole of the rotating component of a hydroelectric generator as described in claim 1, characterized in that, The first plug (1) and the second plug (2) have a first central countersunk hole (13) and a second central countersunk hole (23) respectively on their opposite ends. The pair of first nuts (4) are connected to the bottom surfaces of the first central countersunk hole (13) and the second central countersunk hole (23) respectively.

3. A method for processing connecting holes of a rotating component of a hydropower unit, wherein the rotating component is uniformly provided with 2N connecting holes in its circumference, wherein N is an integer ≥2, the diameter of the connecting holes is D, and a first recessed stop (1-2) is provided on one end face of the rotating component; Its features are, Specifically, the following steps are included: S1. Preparation of raw materials and tools: Prepare the blank, select one end face as the end face to be processed, and coaxially process the first concave stop (1-2) on the end face to be processed; Prepare the boring die, the boring die is uniformly provided with 2N positioning through holes (2-1) in the circumferential direction, and one end face is provided with a first convex stop (2-2) that cooperates with the first concave stop (1-2); Prepare 2X fixing components and 2Y fixing fixtures for the boring die for processing the connecting hole of the rotating component of the hydropower unit as described in claim 1, the fixing components include a second bidirectional screw (3-1), a pair of washers (3-2) passing through the second bidirectional screw (3-1), and a pair of second nuts (3-3) threadedly connected to the second bidirectional screw (3-1), wherein X and Y are both integers ≥1, and X+Y≤N; S2. First-time machining of connecting holes: On the end face to be machined, 2N first through holes (1-1) are initially machined, the diameter of the first through hole (1-1) is d, and d <D; S3. First fixation of the boring die: First, use the first concave stop (1-2) and the first convex stop (2-2) to assemble the boring die coaxially with the end face to be processed. Then, rotate the boring die so that the positioning through hole (2-1) is opposite to the first through hole (1-1). Select 2X sets of positioning through holes (2-1) and the first through hole (1-1) to install the fixing components, and tighten a pair of second nuts (3-3) until a pair of washers (3-2) are connected to a pair of end faces that are separated from the positioning through hole (2-1) and the first through hole (1-1), thus fixing the boring die with the end face to be processed. S4. Secondary machining of connecting holes: Taking the positioning through hole (2-1) as the reference, the unselected first through hole (1-1) is machined into the first target through hole (1-3), and the diameter of the first target through hole (1-3) is D; S5. Secondary fixing of the boring die: Select the first target through hole (1-3) and the positioning through hole (2-1) of the 2Y group to install the boring die fixing fixture for machining the connecting hole of the rotating part of the hydropower unit, and tighten a pair of first nuts (4) until the outer wall of the first truncated cone (12) is connected to the opening of the first target through hole (1-3) and the outer wall of the second cylindrical part (21) is connected to the opening of the positioning through hole (2-1). Fix the first target through hole (1-3) and the positioning through hole (2-1) coaxially, and then remove the fixing assembly; S6. Three-stage machining of connecting holes: Taking the positioning through hole (2-1) as the reference, the remaining first through hole (1-1) is machined into the first target through hole (1-3), thus completing the machining of all connecting holes of the rotating parts of the hydropower unit.

4. The method for machining the connecting hole of a rotating component of a hydroelectric generator according to claim 3, characterized in that, The length of the first cylindrical portion (11) is greater than the length of the second cylindrical portion (21); The diameter of the first bidirectional screw (3) is smaller than the inner diameter of the first cylindrical part (11); the outer diameter of the first cylindrical part (11) is equal to the inner diameter of the second cylindrical part (21), and the outer diameter of the second cylindrical part (21) is smaller than D; The diameter of the positioning through hole (2-1) is R. 定 Satisfying: R 定 >D; The small end diameter of the first frustum portion (12) is R1, and the large end diameter is R2, satisfying: R1 <D<R2; The small end diameter of the second frustum (22) is R3, and the large end diameter is R4, satisfying: R3 <R 定 <R4。 5. A method for machining connecting holes in rotating components of a hydroelectric generator according to claim 4, characterized in that, The length of the first plug (1) is L1, the length of the second plug (2) is L2, and the length of the first cylindrical portion (11) is L1. l 1. The length of the second cylindrical section (21) is l 2. The length of the first through hole (1-1) is H1, and the length of the positioning through hole (2-1) is H2, satisfying: l 1+ l 2 <H1+H2<L1+L2。 6. The method for machining the connecting hole of a rotating component of a hydroelectric generator according to claim 4, characterized in that, L1 = 1.6H1; L2 = 1.1H1; l 1 = 0.9H1; l 2=0.55H1; H2=0.5H1.

7. The method for machining the connecting hole of a rotating component of a hydroelectric generator according to claim 3, characterized in that, The N=8, X=Y=2.

8. The method for machining the connecting hole of a rotating component of a hydroelectric generator according to claim 3, characterized in that, The value is d=0.9D.

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