Positioning device and method for single-group triple turbine guider blade

Abstract

The invention discloses a positioning device and method for a single-group triple turbine guider blade. The problem that in the prior art, clamping and positioning are difficult in numerical control machining in the overhauling process of the triple turbine guider blade is solved. The device comprises a base, a pressing plate and a locking unit, the base is of a cuboid structure, a first groove is formed in the upper surface of the base, and the first groove extends in the left-right direction; the first groove is provided with a first arc positioning surface, a second arc positioning surface, a first end surface positioning surface and a second end surface positioning surface, the first arc positioning surface is the rear side wall of the first groove, the second arc positioning surface is the front side wall of the first groove, and the first end surface positioning surface is the bottom surface of the first groove; the second end face positioning face is a face horizontally extending from the top of the second arc positioning face to the front side. According to the invention, stable clamping and automatic positioning of parts can be realized.

Description

Technical Field

[0001] The invention belongs to the technical field of numerical control machining of aircraft engine turbine blades, and in particular relates to a positioning device and method for a single set of triple turbine guide vane. Background Art

[0002] When a turbofan engine is returned to the factory for overhaul after its service life, the entire engine needs to be disassembled and all its parts need to be fully inspected according to the requirements of the overhaul manual to determine whether it can be installed again and continue to serve. When there are certain defects in the air collecting box welded on the inner and outer ring surfaces of the triple turbine guide vane, it is necessary to remove the welded air collecting box and clean the original welding parts until the base size is exposed and the size requirements of the surface to be welded specified in the overhaul manual are met.

[0003] The traditional renovation method uses manual polishing to remove the welded gas box until the metal matrix of the surface to be welded is exposed. This method not only has high labor costs and low processing efficiency, but also has poor dimensional consistency of the surface to be welded after processing, which is easy to exceed the tolerance. At the same time, the safety of manual operation is also low.

[0004] Since the structure of the triple turbine guide vane is relatively complex, the air collecting box is removed after the service life is over, which is a space arc surface. Due to the limitation of its own structure, there are the following process difficulties:

[0005] (1) The deformation state of parts after the end of service life is different: During the fault detection process, the damage state and dimensional deformation of the three-piece turbine guide vane of the same set are different. When repairing, it is necessary to overhaul each set, which increases the complexity of positioning and processing.

[0006] (2) No full circle and angular reference elements: After service, the blades of the triple turbine guide vane are deformed as a whole, with the opening expanded outward, not the original regular R arc; the inner and outer diameters of the triple turbine guide vane are not full circles, there is no complete arc, and the arc has been deformed, making it impossible to effectively align. At the same time, the lack of angular reference elements makes it impossible to accurately determine the origin of the coordinate system and the angular position of the part to be processed during CNC machining, which in turn affects the machining accuracy and efficiency.

[0007] (3) Structural irregularities and difficult clamping: Due to the poor overall rigidity of the parts, irregular structures, and height differences between the end faces of the inner and outer rings, traditional clamps are difficult to clamp stably and effectively control clamping deformation. The dimensional accuracy requirements after processing cannot be guaranteed, which increases uncertainty and risk during the processing.

[0008] (4) The gas collecting box is made of thin-walled high-temperature alloy. If the positioning is not accurate enough, the tool may be damaged during the processing. Summary of the invention

[0009] The technical problem to be solved by the present invention is that the existing triple turbine guide vane overhaul process has the problem of difficult clamping and positioning in numerical control machining.

[0010] In order to solve the above problems, the present invention also provides a positioning device for a single set of triple turbine guide vane blades, comprising a base, a pressure plate and a locking unit; the base is a rectangular structure, and a first groove is provided on the upper surface of the base, and the first groove extends in the left and right directions; the first groove has a first arc positioning surface, a second arc positioning surface, a first end face positioning surface and a second end face positioning surface, the first arc positioning surface is the rear side wall of the first groove, the second arc positioning surface is the front side wall of the first groove, the first end face positioning surface is the bottom surface of the first groove, and the second end face positioning surface is a surface extending horizontally from the top of the second arc positioning surface to the front side.

[0011] Furthermore, a height difference between the first end surface positioning surface and the second end surface positioning surface of the base is H±0.02 mm, wherein H is a design value of a height difference between an inner peripheral end surface and an outer peripheral end surface of the blade.

[0012] Furthermore, the first arc positioning surface is divided into three sections, namely a left section, a middle section and a right section.

[0013] Furthermore, the radius of the middle section is equal to the radius of the outer arc surface of the blade; and the radii of the left section and the right section are both greater than the radius of the outer arc surface of the blade.

[0014] Furthermore, the radii of the left section and the right section are both 1-2 mm larger than the radius of the outer arc surface of the blade.

[0015] Furthermore, the middle section is symmetrically arranged with the center line of the positioning slot as the axis of symmetry.

[0016] Furthermore, the central angle corresponding to the middle section is within a range of 6°.

[0017] Furthermore, the pressing plate is an arc-shaped plate with a T-shaped cross section.

[0018] Furthermore, a positioning slot is provided on the upper surface of the base, and the positioning slot extends from the middle of the second arc positioning surface toward the front side.

[0019] Furthermore, the pressure plate includes an outer arc positioning surface, an inner arc positioning surface, an outer ring end surface and an inner ring end surface.

[0020] On the other hand, the present invention also provides a method for positioning a single set of triple turbine guide vanes, using the positioning device for the single set of triple turbine guide vanes as described above to position the single set of triple turbine guide vanes.

[0021] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0022] 1) Through the cooperation of the base, the pressure plate and the locking unit, the single assembly clamping, measurement and processing of the triple turbine guide vane can be realized;

[0023] 2) By dividing the first arc positioning surface into three sections, the deformation interference of the parts can be overcome and accurate positioning can be achieved;

[0024] 3) By setting the reference hole, the processing reference of the blade can be mapped and it is convenient for workers to align;

[0025] 4) The positioning device of the present invention can realize stable clamping of the blades in the whole processing process without clamping deformation, so as to ensure the consistency of the dimensions of the parts in the processing process and in the free state.

[0026] Through this device, the parts can be stably clamped and automatically positioned; at the same time, the part processing benchmark is converted to the relevant elements of this device, and the tool / grinding wheel can accurately reach the coordinate position of the surface to be processed, simplifying the CNC processing process. This device breaks the conventional group processing mode of triple turbine guide vanes, and realizes the rapid positioning, efficient and fast processing of a single group of triple turbine guide vanes, with more flexible processing and a wider range of applicable CNC machine tools.

[0027] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0029] Figure 1 A schematic diagram of the structure of placing a single set of triple turbine guide vane on the automatic positioning and reference conversion device of the present invention;

[0030] Figure 2 for Figure 1 Top view of (without the pressure plate);

[0031] Figure 3 for Figure 2 AA section view;

[0032] Figure 4 is a top view of the base of embodiment 1 of the present invention;

[0033] Figure 5 It is an exploded view of embodiment 2 of the present invention;

[0034] Figure 6 for Figure 5 Schematic diagram from another perspective;

[0035] Figure 7 is a cross-sectional view of a clamping assembly portion in Embodiment 2 of the present invention;

[0036] Figure 8 It is the coordinate system of the base and the diagram of various parameters in Example 3 of the present invention.

[0037] Reference numerals:

[0038] 1-base; 11-first arc positioning surface; 111-left section; 112-middle section; 113-right section 113; 12-second arc positioning surface; 13-first end surface positioning surface; 14-second end surface positioning surface; 15-positioning slot; 16-reference hole; 17-locking unit hole; 18-movable positioning block; 181-adjusting bolt; 182-compression spring; 2-blade; 5-clamping assembly; 51-positioning stud; 52-threaded guide sleeve; 521-sleeve ;522-limiting plate;53-clamp base;531-support plate;532-guide sleeve;54-clamp;541-clamping end;542-driving end;543-first through hole;544-first pin hole;545-second pin hole;55-cam wrench;56-first pin shaft;57-second pin shaft;3-locking unit;4-pressure plate;41-outer arc positioning surface;42-inner arc positioning surface;43-outer ring end face;44-inner ring end face;46-arc-shaped long hole. DETAILED DESCRIPTION

[0039] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0040] Example 1

[0041] A specific embodiment of the present invention, as Figure 1-Figure 4As shown, a positioning device for a single set of triple turbine guide vane is disclosed, including a base 1, a pressure plate 4 and a locking unit 3. The base 1 is a basis of the overall structure, and is in the shape of a cuboid, and its upper surface is a working surface. The base 1 has four edges, and the parallelism and verticality between the four edges are within 0.005. The locking unit 3 may include components such as bolts and studs.

[0042] Since the part is a thin-walled part, the overall rigidity is poor and it is easy to deform during clamping. If the rigidity of the fixture is also poor, the positioning surface and the positioning arc will be deformed, then the part cannot be clamped smoothly or the part will be deformed during clamping. In order to solve this problem, the base 1 adopts a rectangular parallelepiped structure, which not only improves the overall rigidity of the fixture, but also facilitates benchmark alignment and establishment of a processing coordinate system.

[0043] See also Figure 1-Figure 3 , there is a first groove on the upper surface of the base 1, the first groove extends in the left-right direction, the first groove has a first arc positioning surface 11, a second arc positioning surface 12, a first end surface positioning surface 13 and a second end surface positioning surface 14, which are used to accurately position the blade 2 (i.e., a single set of triple turbine guide vane, hereinafter referred to as a blade), and the parallelism between each mutually parallel positioning surface is not greater than 0.02. Among them, the first arc positioning surface 11 is used to engage with the outer arc surface of the blade 2, the second arc positioning surface 12 is used to engage with the inner arc surface of the blade 2, the first end surface positioning surface 13 is used to engage with the end surface of the outer periphery of the blade 2, and the second end surface positioning surface 14 is used to engage with the end surface of the inner periphery of the blade 2. The first end surface positioning surface 13 is the bottom surface of the first groove, the first end surface positioning surface 13 is perpendicular to the first arc positioning surface 11, and the first end surface positioning surface 13 is located at the bottom of the first arc positioning surface 11. The second end surface positioning surface 14 is perpendicular to the second arc positioning surface 12 , and the second end surface positioning surface 14 is located on the top of the second arc positioning surface 12 .

[0044] See also Figure 3, with the second end face positioning surface 14 as the main positioning surface of the end face, and the first end face positioning surface 13 as the auxiliary positioning surface of the end face. Since there is a height difference between the end face of the inner periphery and the end face of the outer periphery of the blade 2, in order to avoid over-positioning, when designing the fixture base 1, the height difference between the first end face positioning surface 13 and the second end face positioning surface 14 should be tightened on the basis of the nominal value of the height difference of the corresponding blade 2 mating surface. For example, the height difference design value between the end face of the inner periphery and the end face of the outer periphery of the blade 2 is H, then the height difference between the first end face positioning surface 13 and the second end face positioning surface 14 of the base 1 can be determined as H±0.02mm, and when the blade 2 is processed, the distance dimension between the inner periphery end face and the outer periphery end face is usually processed with the nominal value dimension. Therefore, designing and processing the height difference between the first end face positioning surface 13 and the second end face positioning surface 14 of the base 1 as H±0.02mm can more effectively avoid the occurrence of over-positioning. Even if there is a slight over-positioning of the two positioning surfaces, the first end surface positioning surface 13 can also compensate for it, and the influence on the processing part and the processing reference is negligible.

[0045] See also Figure 2 A positioning slot 15 is also provided on the upper surface of the base 1. The positioning slot 15 extends forward from the middle of the second arc positioning surface 12 and is used to engage with a positioning block extending inwardly on the inner circumference of the blade 2 to achieve angular positioning of the blade 2.

[0046] See also Figure 1-Figure 3 Through the cooperation between the two arc positioning surfaces 11 - 12 , the two end surface positioning surfaces 13 - 14 and the positioning slot 15 , the position of the blade 2 can be preliminarily determined to ensure the stability and accuracy of the blade 2 on the base 1 .

[0047] Further, see Figure 4 The first arc positioning surface 11 is divided into three sections, namely, a left section 111, a middle section 112 and a right section 113. The radius of the middle section 112 is equal to the radius of the outer arc surface of the blade 2, the radii of the left section 111 and the right section 113 are both greater than the radius of the outer arc surface of the blade 2, and the middle section 112 and the left section 111 and the right section 113 are all arc transitions.

[0048] According to the deformation trend of the blade 2 during service, that is, the arcs at the openings of the inner and outer rings tend to expand outward, if the arcs of the inner and outer rings are designed according to conventional arc dimensions, interference is likely to occur between the first arc positioning surface 11 and the blade 2. At the same time, due to the arc deformation at the edges of both ends of the blade 2, its inner arc surface will not interfere with the second arc positioning surface 12. In order to solve this problem, the second arc positioning surface 12 is selected as the main positioning surface, and the first arc positioning surface 11 is selected as the auxiliary positioning surface. The first arc positioning surface 11 is divided into three sections, namely the middle section 112, the left section 111 and the right section 113.

[0049] The middle section 112 of the first arc positioning surface 11 is symmetrically arranged with the center line of the positioning slot 15 as the axis of symmetry. The center angle corresponding to the middle section 112 is within the range of 6°, and cooperates with the outer arc surface of the blade 2 for auxiliary positioning. The arc radius of the left section 111 and the right section 113 is increased by 1-2mm relative to the arc radius of the middle section 112, and is smoothly transferred through appropriate fillets. Since the main positioning and auxiliary positioning arcs are still coordinated with the central segment arc of the blade 2, the theoretical position of the center of the circle will not change. And it is ensured that the blade 2 can still be lowered to the positioning surface for positioning and clamping after deformation. This allows the CNC machining work to be smoothly implemented.

[0050] Furthermore, locking unit holes 17 are evenly distributed in the first groove of the base 1, and the center of the locking unit hole 17 is located on the center line of the blade gap of the blade 2, so that the locking unit 3 can pass through the pressing plate 4 to press the blade. Preferably, there are 6 locking unit holes 17, evenly distributed in the 3 blade gaps of the blade 2.

[0051] See also Figure 1 , Figure 3 The pressing plate 4 is an arc-shaped plate with a T-shaped cross section. The pressing plate 4 includes an outer arc positioning surface 41 , an inner arc positioning surface 42 , an outer ring end surface 43 and an inner ring end surface 44 .

[0052] The outer arc positioning surface 41 is engaged with the inner arc surface on the outer side of the top of the blade 2, and the inner arc positioning surface 42 is engaged with the inner arc surface on the inner side of the top of the blade 2. A large clearance is used between the two arc surfaces, and the clearance range is 0.4-0.6mm. The outer ring end surface 43 is engaged with the top surface of the outer side of the blade 2, and the inner ring end surface 44 is engaged with the top surface of the inner side of the blade 2.

[0053] The pressing plate 4 is provided with 6 locking through holes, which are arranged one by one corresponding to the locking unit holes 17 on the base 1. After the blade 2 is placed in the first groove of the base 1, the pressing plate 4 is pressed on the top of the blade 2, and then the locking unit 3 is inserted into the locking unit hole 17 on the base 1 through the locking through hole, and then locked with a nut to press the blade 2 on the base 1.

[0054] This clamping method can prevent the blade 2 from deforming during the clamping process, avoid the processing area, and ensure that the pressure plate 4 is almost completely in contact with the inner and outer ring end faces of the blade 2, making the clamping force uniform and stable.

[0055] In addition, in order to facilitate positioning during processing, a reference hole 16 is also provided on the upper surface of the base 1. Figure 2 as well as Figure 4The reference hole 16 is arranged at the lower left corner of the base 1 , a distance below the second arc positioning surface 12 and to the left of the positioning slot 15 , and it is necessary to ensure that the reference hole 16 is not blocked by the inwardly protruding part of the inner arc surface of the blade 2 .

[0056] By setting the reference hole 16, the angular positioning of the blade 2 is achieved, and it can also be used as a reference point to establish an accurate processing coordinate system, simplify the CNC processing process, and improve the processing accuracy and consistency.

[0057] The base 1 is provided with a reference hole 16, and the blade 2 is positioned by the arc surface and the slot. After being placed in the device, the Y axis passes through the center of the reference hole 16. The origin of the NC program coordinate system can be directly determined by the distance between the center position of the reference hole 16 and the edge of the base 1. At the same time, the processing reference of the blade 2 is converted to the reference hole and each positioning surface of the device, and the tool / grinding wheel can accurately reach the coordinate position of the surface to be processed of the blade 2, simplifying the NC processing process.

[0058] The device breaks the conventional group processing mode of triple turbine guide vane, realizes rapid positioning, efficient and fast processing of a single set of triple turbine guide vane, has more flexibility in processing, and is applicable to a wider range of CNC machine tools. Compared with the prior art, the positioning device for a single set of triple turbine guide vane provided in this embodiment can realize automatic positioning of the vane 2 and stable clamping.

[0059] Example 2

[0060] This embodiment 2 relates to a positioning device for a single set of triple turbine guide vane, and this embodiment 2 is a technical solution further improved on the basis of embodiment 1. The same parts as embodiment 1 are not described here, and the parts different from embodiment 1 are described in detail below in conjunction with the accompanying drawings.

[0061] See also Figure 5-Figure 7 The base 1 includes a movable positioning block 18 , on which the first arc positioning surface 11 and the first end surface positioning surface 13 are arranged. The movable positioning block 18 can reciprocate relative to the base 1 to approach or move away from the second arc positioning surface 12 .

[0062] The movable positioning block 18 is provided with two parallel threaded holes, and the base 1 is provided with two corresponding threaded holes. The threaded holes on the base 1 and the movable positioning block 18 have opposite rotation directions. The movable positioning block 18 is connected to the base 1 through an adjusting bolt 181, and the movable positioning block 18 can be driven to reciprocate relative to the base 1 by rotating the adjusting bolt 181. This arrangement can be applied to situations where the deformation of the blade 2 is large. In addition, by controlling the torque of the two adjusting bolts 181, the clamping force on the blade 2 can be controlled. By adjusting the clamping force, the deformation of the blade 2 to a certain extent can be corrected.

[0063] Preferably, a blind hole is provided between the two threaded holes on the movable positioning block 18. A blind hole located between the two threaded holes is correspondingly provided on the base 1, and a compression spring 182 is provided between the two blind holes. By this arrangement, the error caused by the thread gap of the adjusting bolt 181 can be avoided.

[0064] Furthermore, the bottom surface of the movable positioning block 18 is inclined at a certain angle relative to the bottom surface of the base 1. Correspondingly, the bottom surface of the groove on the base 1 for accommodating the movable positioning block 18 has the same inclination angle as the bottom surface of the movable positioning block 18, and at the same time, the axis of the threaded hole for setting the adjustment bolt 181 has the same inclination angle. Through this arrangement, while adjusting the first arc positioning surface 11, the height difference between the first end surface positioning surface 13 and the second end surface positioning surface 14 can also be adjusted to achieve correction of the deformation of the blade 2 in the height direction.

[0065] The positioning device for the single-group triple turbine guide vane of the second embodiment further comprises a clamping assembly 5. The clamping assembly 5 is arranged on the base 1 and is used for fast clamping or releasing the pressure plate 4.

[0066] See also Figure 5-Figure 7 The clamping assembly 5 includes a positioning stud 51 , a threaded guide sleeve 52 , a clamp base 53 , a clamp 54 , a cam wrench 55 , a first pin 56 and a second pin 57 .

[0067] The positioning stud 51 is fixedly arranged on the base 1, and the threaded guide sleeve 52 is sleeved on the positioning stud 51 and can move up and down relative to the positioning stud 51. The top of the threaded guide sleeve 52 is connected to the clamping plate base 53, and the threaded guide sleeve 52 can rotate relative to the clamping plate base 53. The threaded guide sleeve 52 includes a sleeve 521 located at the top and a limiting plate 522 located at the bottom of the sleeve 521, and the diameter of the limiting plate 522 is larger than the diameter of the sleeve 521. The sleeve 521 and the limiting plate 522 are provided with threaded through holes inside, which are used to be sleeved on the positioning stud 51.

[0068] The clamping plate base 53 includes a support plate 531 and a guide sleeve 532 located above the support plate 531. Through holes are provided in the guide sleeve 532 and the support plate 531. The clamping plate base 53 is sleeved on the sleeve 521 of the threaded guide sleeve 52 through the through hole, and the support plate 531 is supported on the upper surface of the limit plate 522. When the threaded guide sleeve 52 is rotated, the clamping plate base 53 can move up and down relative to the positioning stud 51 together with the threaded guide sleeve 52. At the same time, the clamping plate base 53 can rotate relative to the threaded guide sleeve 52.

[0069] The clamping plate 54 includes a clamping end 541, a driving end 542, a first through hole 543, a first pin hole 544 and a second pin hole 545. The diameter of the first through hole 543 is slightly larger than the outer diameter of the guide sleeve 532 of the clamping plate base 53, and the clamping plate 54 can be sleeved on the outer peripheral surface of the guide sleeve 532 through the first through hole 543. The first pin hole 544 is arranged in the horizontal direction, and the central axis of the first pin hole 544 intersects the central axis of the first through hole 543 vertically. The third pin hole is correspondingly arranged on the guide sleeve 532 of the clamping plate base 53. There are two first pin shafts 56, which are respectively inserted into the first pin hole 544 and the third pin hole from both sides, so that the clamping plate 54 and the clamping plate base 53 are rotatably connected together, so that the clamping plate 54 can rotate within a certain range relative to the clamping plate base 53 around the central axis of the first pin shaft 56.

[0070] The two sides of the driving end 542 of the clamping plate 54 are lugs protruding forward, and there is a groove in the middle of the two lugs. The two lugs are correspondingly provided with second pin holes 545, and the cam wrench 55 is provided with an eccentric fourth pin hole. The cam wrench 55 is arranged in the groove between the two lugs through the second pin shaft 57. The bottom of the cam wrench 55 abuts against the upper surface of the support plate 531 of the clamping plate base 53. Pulling the handle of the cam wrench 55 can drive the driving end 542 of the clamping plate 54 to move upward or downward, so that the clamping end 541 of the clamping plate 54 moves downward to clamp the pressure plate 4 or moves upward to release the pressure plate 4.

[0071] At the same time, a locking unit hole 17 is provided on the base 1 at the bottom of the first groove on the side away from the clamping assembly 5, and a locking unit 3 is provided in the locking unit hole 17. An arc-shaped long hole 46 is provided in the middle of the pressing plate 4, and the top of the locking unit 3 passes through the arc-shaped long hole 46 and is locked by a nut. The pressing plate 4 can move along the arc-shaped long hole 46 relative to the locking unit 3.

[0072] According to the positioning device of the single-group triple turbine guide vane of embodiment 2, when working, the movable positioning block 18 is first moved to a position away from the second arc positioning surface 12, and the clamping plate 54 of the clamping assembly 5 is rotated aside to avoid interference when installing the blade 2. The locking nut on the pressure plate 4 is loosened, and the pressure plate 4 is pulled along the arc-shaped long hole to move the pressure plate 4 to the side to avoid interference when installing the blade 2.

[0073] Then place the blade 2 into the first groove of the base 1 so that the inner arc surface of the blade 2 is in close contact with the second arc positioning surface 12, the inner circumferential end surface of the blade 2 is in close contact with the second end surface positioning surface 14, and the positioning block on the inner circumferential surface of the blade 2 is engaged in the positioning slot 15.

[0074] Then, the movable positioning block 18 is moved to a position where the first arc positioning surface 11 is engaged with the outer arc surface of the blade 2 and a certain pressing force is applied.

[0075] Then place the pressure plate 4 on the top of the blade 2, so that the outer arc positioning surface 41 of the pressure plate 4 is engaged with the inner arc surface on the outer side of the top of the blade 2, the inner arc positioning surface 42 is engaged with the inner arc surface on the inner side of the top of the blade 2, the outer ring end surface 43 is engaged with the top surface of the outer side of the blade 2, and the inner ring end surface 44 is engaged with the top surface of the inner side of the blade 2.

[0076] Then a nut is used to lock the top of the locking unit 3 so that one end of the pressing plate 4 presses the blade 2 .

[0077] Finally, the clamping plate 54 is rotated to a position where the clamping end 541 is located above the pressure plate 4 , and the handle of the cam wrench 55 is pulled to move the clamping end 541 of the clamping plate 54 downward to clamp the pressure plate 4 , thereby pressing the blade 2 .

[0078] According to the device of this embodiment 2, there is no need to repeatedly tighten multiple locking units, and the blade 2 can be pressed and positioned conveniently and quickly. It is more tolerant to the deformation of the blade 2 and can correct the deformation of the blade 2 within a certain range.

[0079] Example 3

[0080] This embodiment 3 relates to a positioning method for CNC machining of triple turbine guide blades of an engine, which uses the positioning device for a single set of triple turbine guide vanes in embodiment 1 or 2 to position a single set of triple turbine guide vanes.

[0081] The required dimensions and actual dimensions of the design drawings of the positioning device for the single set of triple turbine guide vane involved in this embodiment 3 are shown in Table 1. It is necessary to determine the zero point position and coordinate system position of the CNC program, that is, to determine the zero point position of the O coordinate system and the directions of the X-axis, Y-axis, and Z-axis.

[0082] Table 1 Examples of dimensions required by device design drawings and actual dimensions

[0083] Size Item Drawing size required Actual size X’ 60.4 60.41 Y’ 15 14.99 G° 2° 1°58’ R R200±0.1 R199.95 A 35±0.1 35.02

[0084] The method comprises the following steps:

[0085] S1: Establish a blade coordinate system: Take the bottom transverse edge of the base 1 of the present invention as the X' axis, the left longitudinal edge as the Y' axis, the edge in the thickness direction as the Z axis, and the intersection of the three edges as the origin of the O' coordinate system to establish a blade coordinate system, such as Figure 8 shown.

[0086] The base 1 was measured, and the actual values ​​of X' and Y' of the reference hole 16 of the base 1 were measured to be 60.41 and 14.99 respectively, the radius R of the second arc positioning surface 12 was measured to be 199.95, the maximum distance A from the second arc positioning surface 12 to the X-axis was measured to be 35.02, and the actual value of the angle G° between the center line of the positioning slot 15 and the line connecting the center of the reference hole 16 and the center of the second arc positioning surface 12 was 1°58'.

[0087] S2: The direction of the coordinate axis remains unchanged, the center of the reference hole M is used as the initial zero position of the NC program, and the machine tool coordinate system On' is established on the NC machine tool.

[0088] S21: Press the fixture onto a dry machine bed, with the N side facing the operator and the B side roughly parallel to the X-axis direction of the machine spindle. Press the four corners of the top surface of the fixture and tighten it slightly.

[0089] S22: Establishing the Z-axis zero point: using the top surface of the base 1 (i.e., the plane where the reference hole 16 is located) to align the tool and determine the Z-axis zero point;

[0090] S22: Establishing the Xn' axis: straightening the front side surface N of the base 1 from left to right along the X axis direction of the machine tool spindle, and setting it as the Xn' axis;

[0091] S23: Determine the center position of the machine tool coordinate system On': measure the center of the positioning hole 16, obtain the center coordinates, move the Xn' axis zero point to the center position of the positioning hole 16, keep the direction unchanged, and establish the machine tool coordinate system On'.

[0092] S3: Take the engine axis vector as the final zero position of the CNC program and establish the machining coordinate system OXYZ on the CNC machine tool.

[0093] S31: Calculate the Y-axis offset compensation value: The Y-axis offset compensation value is the amount by which the Y-axis is offset from the origin of the blade coordinate system to the origin of the machining coordinate system along the X-axis direction. The value is set to a, a=X'-Xn. If a is a positive value, the Y-axis should be offset by a in the positive direction of the X-axis. If a is a negative value, the Y-axis should be offset by -a in the negative direction of the X-axis. In this embodiment, the Y-axis should be translated by 0.01 mm (60.4-60.41=-0.01) in the negative direction of the X-axis.

[0094] S32: Calculate the X-axis offset compensation value: The X-axis offset compensation value is the amount by which the X-axis is offset from the origin of the blade coordinate system to the origin of the machining coordinate system along the Y-axis direction. The value is set to B, where B==Rn-An+Yn. The X-axis should be offset by b along the negative direction of the Y-axis. In this embodiment, the translation along the negative direction of the Y-axis is Y=R-A+Y'=199.95-35.02+14.99=149.94mm.

[0095] S33: Establishing the processing coordinate system OXYZ: Moving the origin of the initial coordinate system in steps, the directions of the X-axis, Y-axis and Z-axis remain unchanged, and the processing coordinate system OXYZ can be obtained.

[0096] Through the above method, the blade 2 can be accurately positioned. After the positioning is completed, the CNC center can process the inner and outer arc surfaces of the blade 2 according to the CNC program to remove the air collecting box on the surface.

[0097] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A positioning device for a single set of triple turbine guide vane, characterized in that: It includes a base, a pressure plate and a locking unit; a first groove is provided on the upper surface of the base, and the first groove extends in the left-right direction; the first groove has a first arc positioning surface, a second arc positioning surface, a first end face positioning surface and a second end face positioning surface, the first arc positioning surface is the rear side wall of the first groove, the second arc positioning surface is the front side wall of the first groove, the first end face positioning surface is the bottom surface of the first groove, and the second end face positioning surface is a surface extending horizontally from the top of the second arc positioning surface to the front side.

2. The positioning device for a single set of triple turbine guide vane according to claim 1, characterized in that: The height difference between the first end surface positioning surface and the second end surface positioning surface of the base is H±0.02 mm, wherein H is the height difference between the inner peripheral end surface and the outer peripheral end surface of the blade.

3. The positioning device for a single set of triple turbine guide vane according to claim 1, characterized in that: The first arc positioning surface is divided into three sections, namely a left section, a middle section and a right section.

4. The positioning device for a single set of triple turbine guide vane according to claim 3, characterized in that: The radius of the middle section is equal to the radius of the outer arc surface of the blade; the radii of the left section and the right section are both greater than the radius of the outer arc surface of the blade.

5. The positioning device for a single set of triple turbine guide vane according to claim 4, characterized in that: The radii of the left section and the right section are both 1-2 mm larger than the radius of the outer arc surface of the blade.

6. The positioning device for a single set of triple turbine guide vane according to claim 5, characterized in that: The middle section is symmetrically arranged with respect to the center line of the positioning slot.

7. The positioning device for a single set of triple turbine guide vane according to claim 6, characterized in that: The central angle corresponding to the middle section is within the range of 6°.

8. The positioning device for a single set of triple turbine guide vane according to claim 1, characterized in that: The pressing plate is an arc-shaped plate with a T-shaped cross section.

9. The positioning device for a single set of triple turbine guide vane according to claim 8, characterized in that: A positioning slot is also provided on the upper surface of the base, and the positioning slot extends from the middle of the second arc positioning surface toward the front side.

10. A method for positioning a single set of triple turbine guide vane, characterized in that: The positioning device for a single set of triple turbine guide vanes according to any one of claims 1 to 9 is used to position a single set of triple turbine guide vanes.

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