Coating mask jig for turbine rotor blade

Abstract

The application discloses a coating shielding clamp for a turbine moving blade, which comprises a clamp body, a containing space for containing a part of the turbine moving blade is arranged in the clamp body, a threaded through hole is arranged on the top wall of the clamp body and a through slot for the blade root to pass through is arranged on the bottom wall of the clamp body; two shielding aprons are connected to the first side and the second side of the clamp body respectively to cover the first open port and the second open port, a feature hole is arranged on the shielding apron, the contour of the feature hole corresponds to the contour of a contact surface and the feature hole and the contact surface are aligned with each other; and a threaded rod can be screwed into and through the threaded through hole to abut against the top surface of the blade crown and make the bottom surface of the airfoil of the turbine moving blade abut against the bottom wall of the clamp body, so that the turbine moving blade is clamped in the vertical direction. The application significantly improves the assembly precision and effectively reduces the clamping difficulty of the turbine moving blade, improves the clamping precision and repeatability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas turbines in general, and more particularly, to a coating masking fixture for turbine moving blades. BACKGROUND

[0002] In the art, the last stage turbine moving blades are often designed with a structure of a shroud to reduce vibration and assembly gap during operation. At the same time, a wear-resistant coating or hard alloy coating is required to be sprayed on the contact surface between the shrouds of the blades, and the non-contact surface area of the shroud needs to be masked during spraying. Therefore, a masking fixture is needed to mask the non-contact surface area and to peripherally protect the contact surface. Since the shroud area of the turbine moving blade is generally simple in structure, the surface is a machined smooth surface, so it is difficult to design the coating masking fixture.

[0003] So far, the conventional shroud coating masking mainly adopts the method of adhesive tape masking and the method of combination of adhesive tape and simple coaming. The adhesive tape masking method is easily burned and peeled off under the impact of high-temperature and high-speed flame flow during spraying, which leads to a series of quality problems such as over-spraying of the coating, contamination of the coating, and size out-of-tolerance. The simple fixture coaming masking has problems of poor protection effect, inaccurate positioning, and easy peeling. SUMMARY

[0004] Therefore, in order to eliminate or alleviate the above problems, especially the problem of difficult clamping caused by the simple structure of the top of the shroud, the present application discloses a coating masking fixture for turbine moving blades, which can ensure the quality of the spraying area and facilitate clamping.

[0005] According to an embodiment of the present application, a coating shielding jig for a turbine rotor blade is provided, the turbine rotor blade comprising a blade profile, a blade root and a blade crown, the blade crown comprising two contact surfaces for contacting other blade crowns, characterized in that the coating shielding jig comprises: a jig main body, in which an accommodation space for accommodating a part of the turbine rotor blade is arranged, the jig main body being composed of a first base block and a second base block, each of the first base block and the second base block having a base block top wall, a base block bottom wall and a base block side wall connected between the base block top wall and the base block bottom wall, the base block top wall, the base block bottom wall and the base block side wall forming a U-shaped groove, wherein, when the first base block and the second base block are connected together to constitute the jig main body, the open directions of the U-shaped grooves of the first base block and the second base block are opposite to each other, so that the jig main body has a first open port on a first side and a second open port on a second side opposite to the first side, and so that the two contact surfaces of the blade crown accommodated in the accommodation space are respectively directed to the first open port and the second open port; and two shielding aprons, the two shielding aprons being respectively connected to the first side and the second side of the jig main body to cover the first open port and the second open port, on which a feature hole is arranged, the feature hole having an outline corresponding to that of a corresponding contact surface of the blade crown and being aligned with the contact surface.

[0006] Further, the base block top wall of the first base block and the second base block forms a top wall of the jig main body and the base block bottom wall of the first base block and the second base block forms a bottom wall of the jig main body, on the top wall of the jig main body a threaded through hole is arranged and on the bottom wall of the jig main body a through slot is arranged for the blade root of the turbine rotor blade to pass through.

[0007] Further, the coating shielding jig further comprises a threaded rod extending in a vertical direction, the threaded rod being configured to cooperate with the threaded through hole, so that the threaded rod can be screwed into and through the threaded through hole to abut against a top surface of the blade crown of the turbine rotor blade and make a bottom surface of the blade profile of the turbine rotor blade abut against the bottom wall of the jig main body, so that the turbine rotor blade is clamped in the vertical direction.

[0008] Further, the top wall and the bottom wall of the jig main body are flat and parallel to each other, and perpendicular to the extension direction of the threaded rod.

[0009] Further, a projection of the turbine rotor blade on the top wall of the jig main body in the vertical direction does not exceed the outline range of the top wall.

[0010] Further, the shielding fence comprises a flat feature segment provided with the feature hole and an auxiliary segment not provided with the feature hole.

[0011] Further, the contact surface of the shroud of the turbine rotor blade is flat and flush with the flat feature segment of the shielding fence after the shielding fence is connected to the clamp body.

[0012] Further, the first base block is provided with at least one first threaded hole on the first side and the second side, and the second base block is provided with at least one second threaded hole on the first side and the second side.

[0013] Further, one of the two shielding fences is connected to the clamp body by means of the at least one first threaded hole and the at least one second threaded hole on the first side and corresponding screws, and the other of the two shielding fences is connected to the clamp body by means of the at least one first threaded hole and the at least one second threaded hole on the second side and corresponding screws.

[0014] Further, a first step portion is provided at an edge of the base block top wall of the first base block facing the second base block, a first through hole is provided in the first step portion, and a second step portion is provided at an edge of the base block top wall of the second base block facing the first base block, a second through hole is provided in the second step portion, wherein the first base block and the second base block are connected to each other by means of the first step portion and the second step portion, and the first through hole and the second through hole are aligned with each other to form the threaded through hole.

[0015] Further, an edge of the base block bottom wall of the first base block facing the second base block is spaced apart from an edge of the base block bottom wall of the second base block facing the first base block to form the through slot.

[0016] Further, the coating shielding clamp further comprises at least one transverse limiting piece arranged in the accommodation space, which is configured to limit the positioning of the turbine rotor blade in a transverse direction perpendicular to the vertical direction by means of shape fitting.

[0017] Through the above arrangement, the clamping and fixing on the shroud of the turbine rotor blade is realized through the structural design of the coating shielding clamp with two base blocks matched with each other, the clamping process is simple and convenient, and the artificial working hours can be effectively reduced. In addition, the spraying area is regarded as a special feature area and is embodied on the shielding fence (especially the feature segment of the shielding fence), and is used as a standard accessory, so that on the one hand it is relatively easy to precisely process, and on the other hand it has strong interchangeability in use. BRIEF DESCRIPTION OF DRAWINGS

[0018] The above and other features and advantages of the present application will become more apparent by describing in detail preferred embodiments thereof with reference made to the accompanying drawings in which:

[0019] Figure 1 is a schematic perspective view showing a turbine rotor blade;

[0020] Figure 2 is a schematic perspective view showing a coating shield jig according to an embodiment of the present application, wherein a shield enclosure is removed to show the internal structure of the coating shield jig;

[0021] Figure 3 is a schematic perspective view showing Figure 2 is a schematic perspective view showing a coating shield jig according to an embodiment of the present application, wherein a turbine rotor blade positioned within the coating shield jig is shown;

[0022] Figure 4 is a schematic perspective view showing Figure 3 is a schematic bottom perspective view showing a coating shield jig according to an embodiment of the present application;

[0023] Figure 5 is a schematic side view showing Figure 3 is a schematic side view showing a coating shield jig according to an embodiment of the present application, wherein one base block is removed;

[0024] Figure 6 is a schematic perspective view showing a shield enclosure of a coating shield jig according to an embodiment of the present application;

[0025] Figure 7 is a schematic side view showing Figure 3 is a schematic side view showing a coating shield jig according to an embodiment of the present application, wherein a shield enclosure is mounted to the coating shield jig;

[0026] Figure 8 is a schematic exploded perspective view showing Figure 2

[0027] wherein the reference numerals are as follows:

[0028] 10 turbine rotor blade

[0029] 101 airfoil

[0030] 102 blade root

[0031] 103 blade tip

[0032] 103a contact surface

[0033] ​103b contact surface

[0034] 100 Coating Masking Fixture

[0035] 1. Fixture body

[0036] 1a First side

[0037] 1b Second side

[0038] 11 First base block

[0039] 11S First Step

[0040] 111 Base Block Top Wall

[0041] 112 Base wall

[0042] 113 Base Block Sidewall

[0043] 12 Second base block

[0044] 12S Second Step

[0045] 121 Base Block Top Wall

[0046] 122 Base wall

[0047] 123 Base Block Sidewall

[0048] 2. Sheltering panels

[0049] 21 Feature Holes

[0050] 22 Flat Feature Sections

[0051] 23 Auxiliary Section

[0052] 3. Threaded rod

[0053] 4 Lateral limiting components

[0054] H threaded through hole

[0055] HA First Through Hole

[0056] HB Second Through Hole

[0057] H1 First threaded hole

[0058] H2 Second threaded hole

[0059] S-shaped space

[0060] G through groove Detailed Implementation

[0061] To make the objectives, technical solutions, and advantages of the present invention clearer, the following embodiments are provided to further illustrate the present invention in detail.

[0062] The present invention aims to provide a coating masking fixture 100 to clamp a turbine blade 10 and mask the non-coating areas of the turbine blade 10 while exposing only the coating areas, thereby facilitating the coating process on the turbine blade 10. Figure 1 As shown, the turbine blade 10 includes an airfoil 101, a blade root 102, and a blade crown 103. The blade crown 103 includes two contact surfaces 103a and 103b for contacting other blade crowns. The structure of the turbine blade 10 is known to those skilled in the art and will not be described in detail here.

[0063] Combination Figures 2 to 8 As shown, the coating masking fixture 100 according to an embodiment of the present invention may include a fixture body 1 and two masking panels 2.

[0064] like Figure 2 and Figure 3 As shown, a receiving space S is provided within the clamp body 1 for accommodating a portion of the turbine blade 10 (particularly the blade profile 101 and blade crown 103 of the turbine blade 10). Preferably, the clamp body 1 may be composed of a first base block 11 and a second base block 12, each of the first base block 11 and the second base block 12 having a base block top wall 111 or 121, a base block bottom wall 112 or 122, and a base block side wall 113 or 123 connecting the base block top wall 111 or 121 and the base block bottom wall 112 or 122. The base block top wall 111 or 121, the base block bottom wall 112 or 122, and the base block side wall 113 or 123 form a U-shaped groove, where a U-shaped groove refers to a groove-like structure open on three sides. Figure 2 and Figure 3 As shown, when the first base block 11 and the second base block 12 are connected together to form the clamp body 1, the opening directions of the U-shaped grooves of the first base block 11 and the second base block 12 are opposite to each other (i.e., they are mated together opposite to each other), so that the clamp body 1 obtained by connecting the first base block 11 and the second base block 12 is only open on opposite sides, that is, it has a first opening on the first side 1a and a second opening on the second side 1b opposite to the first side 1a. The two contact surfaces 103a and 103b of the blade crown 103 of the turbine blade 10 housed in the housing space S point to the first opening and the second opening of the clamp body 1, respectively.

[0065] The structure of the clamp body 1 of the present invention is not limited to this; it can also be a single integral structure, rather than necessarily consisting of two separate base blocks.

[0066] like Figure 6 and Figure 7 As shown, two shielding panels 2 (in Figure 6 and Figure 7Only one of them is shown in the diagram. The other shielding plate (located on the opposite side of the shielding plate shown) is connected to the first side 1a and the second side 1b of the clamp body 1 to cover the first and second openings of the clamp body 1. A feature hole 21 is provided on the shielding plate 2. The outline of the feature hole 21 corresponds to the outline of the corresponding contact surfaces 103a and 103b of the blade crown 103 of the turbine blade 10, and the feature hole 21 is aligned with the contact surfaces 103a and 103b.

[0067] like Figure 2 As shown, in the clamp body 1 composed of the first base block 11 and the second base block 12 described above, the top walls 111 or 121 of the first base block 11 and the second base block 12 form the top wall of the clamp body 1, and the bottom walls 112 or 122 of the first base block 11 and the second base block 12 form the bottom wall of the clamp body 1. A threaded through hole H is provided on the top wall of the clamp body 1, and a through groove G is provided on the bottom wall of the clamp body 1 for the blade root 102 of the turbine moving blade 10 to pass through.

[0068] The coating masking fixture 100 according to an embodiment of the present invention may include a threaded rod 3 extending in a vertical direction. The threaded rod 3 is configured to engage with a threaded through hole H, such that the threaded rod 3 can be screwed into and through the threaded through hole H to abut against the top surface of the crown 103 of the turbine blade 10 and the bottom surface of the airfoil 101 of the turbine blade 10 abut against the bottom wall of the fixture body 1, thereby clamping the turbine blade 10 in the vertical direction. During clamping, the turbine blade 10 is fixed on the lower worktable (not shown), and the clamp body 1 is fitted over the blade profile 101 and blade crown 103 of the turbine blade 10. Then, the threaded rod 3 is screwed in and passes through the threaded through hole H to contact the top surface of the blade crown 103. Further downward screwing of the threaded rod 3 against the top surface of the blade crown 103 raises the clamp body 1, causing the bottom surface of the blade profile 101 to abut against the inner surface of the bottom wall of the clamp body 1. Thus, the turbine blade 10 is clamped vertically using the threaded rod 3 and the bottom wall of the clamp body 1. Typically, clamping the turbine blade 10 vertically is sufficient to ensure its stable position. In this invention, a nut or other component can also be used instead of the threaded rod 3 described above.

[0069] In particular, such as Figures 2 to 4 As shown, the top and bottom walls of the clamp body 1 can be flat and parallel to each other, and perpendicular to the extension direction of the threaded rod 3. However, the specific arrangement of the top and bottom walls of the clamp body 1 of the present invention is not limited to this.

[0070] In this invention, the projection of the turbine blade 10 along the vertical direction onto the top wall of the clamp body 1 does not exceed the contour range of the top wall. This enables the clamp body 1 to completely surround the blade profile 101 and the crown 103 of the turbine blade 10. In a particularly preferred embodiment of the invention, the first base block 11 and the second base block 12 can be designed based on the shape of the turbine blade 10 (especially the blade profile 101 of the turbine blade 10) as follows: Figure 2 and Figure 3 The structure shown allows it to conform to the shape of the turbine blade 10 for easy clamping and spraying, while also miniaturizing the size of the coating masking fixture 100. The specific structural shapes of the first base block 11 and the second base block 12 of the present invention are not limited to this, as long as they can completely surround the blade profile 101 and the blade crown 103 of the turbine blade 10.

[0071] refer to Figure 6 and Figure 7 As shown, the shielding panel 2 may include a flat feature section 22 with feature holes 21 and an auxiliary section 23 without feature holes 21. In other words, the specific structural shape of the shielding panel 2 is not limited; of course, the shielding panel 2 may have the following characteristics: Figure 6 and Figure 7 The shape shown can advantageously conform to the shape of the crown 103 of the turbine blade 10, thereby promoting the miniaturization of the structural dimensions of the coating masking fixture 100. However, the masking plate 2 can also adopt other shapes, as long as it can adapt to the shape of the first or second side of the fixture body 1 and cover the corresponding first or second opening, and the section provided with the feature hole 21 is flat to match the contact surfaces 103a, 103b of the crown 103.

[0072] In a particularly preferred embodiment, the contact surfaces 103a, 103b of the blade crown 103 of the turbine blade 10 are flat and flush with the flat feature section 22 of the shielding plate 2 after the shielding plate 2 is connected to the clamp body 1. This flushing facilitates spraying, so that only the contact surfaces 103a, 103b of the blade crown 103 are sprayed with a wear-resistant coating or a hard alloy coating, without spraying these coatings onto other areas of the turbine blade 10.

[0073] exist Figure 6In the illustrated embodiment, the shielding plate 2 can be composed of multiple flat plates, one of which is the flat feature section 22 described above, while the remaining plates are auxiliary sections 23. These plates can be installed independently onto the fixture body 1, or they can be prefabricated as a single piece and installed together onto the fixture body 1. Preferably, the flat feature section 22 and the auxiliary sections 23 are separate; in other words, the flat feature section 22 can be installed independently. This allows for the design of corresponding flat feature sections 22 for the contact surfaces 103a and 103b of different turbine blades 10 with different shapes or sizes, thereby improving the flexibility of use of the coating shielding fixture 100 at a lower manufacturing cost.

[0074] The following will refer to Figures 2 to 3 as well as Figures 6 to 7 The preferred installation method of the shielding plate 2 is described in detail. In an embodiment of the invention, the first base block 11 may have at least one first threaded hole H1 (two shown in the drawings) on both the first side 1a and the second side 1b of the clamp body 1, and the second base block 12 may have at least one second threaded hole H2 (two shown in the drawings) on both the first side 1a and the second side 1b of the clamp body 1. One of the two shielding plates 2 is connected to the clamp body 1 by means of at least one first threaded hole H1 and at least one second threaded hole H2 on the first side 1a and a corresponding screw (correspondingly, a corresponding number of through holes are also provided in the shielding plate 2 for the screw to pass through), and the other of the two shielding plates 2 is connected to the clamp body 1 by means of at least one first threaded hole H1 and at least one second threaded hole H2 on the second side 1b and a corresponding screw (correspondingly, a corresponding number of through holes are also provided in the shielding plate 2 for the screw to pass through). Of course, the connection method between the shielding plate 2 and the clamp body 1 of the present invention is not limited to this, and any existing method can be used for installation.

[0075] like Figures 2 to 3 as well as Figure 8 As shown, in an embodiment of the present invention, a first step portion 11S may be provided at the edge of the base top wall 111 of the first base block 11 facing the second base block 12, and a first through hole HA may be provided in the first step portion 11S. Similarly, a second step portion 12S may be provided at the edge of the base top wall 121 of the second base block 12 facing the first base block 11, and a second through hole HB may be provided in the second step portion 12S. The first base block 11 and the second base block 12 can be connected to each other by means of the first step portion 11S and the second step portion 12S (the first step portion 11S can rest on the second step portion 12S), and the first through hole HA and the second through hole HB are aligned with each other to form the threaded through hole H for the threaded rod 3 to pass through, as described above.

[0076] like Figures 2 to 4As shown, the edge of the base wall 112 of the first base block 11 facing the second base block 12 and the edge of the base wall 122 of the second base block 12 facing the first base block 11 are spaced apart to form a through groove G through which the blade root 102 of the turbine blade 10 passes. The width of the through groove G is designed to allow the blade root 102 of the turbine blade 10 to pass through but not the blade profile 101 of the turbine blade 10 to pass through.

[0077] like Figures 2 to 4 As shown, the coating masking fixture 100 may further include at least one lateral limiting member 4 (two shown in the figures) disposed within the receiving space S of the fixture body 1. The lateral limiting member 4 is configured to restrict the positioning of the turbine blade 10 in the lateral direction perpendicular to the vertical direction through a form fit. Thus, in addition to clamping the turbine blade 10 in the vertical direction, the coating masking fixture 100 of the present invention can also provide clamping of the turbine blade 10 in the lateral direction through the lateral limiting member 4, thereby further ensuring that the position of the turbine blade 10 does not change during the spraying process. Preferably, the side surface of the lateral limiting member 4 may have a shape that matches the side surface of the blade profile 101 of the turbine blade 10.

[0078] The arrangement method of this invention simplifies and facilitates the clamping process, effectively reducing manual labor time. Furthermore, the spraying area is considered a special feature area on the masking panel (especially the characteristic sections of the masking panel) and is included as a standard component, making it easier to precision-machine and ensuring strong interchangeability during use.

[0079] The above description is only a preferred embodiment of the present invention and is not intended to limit the invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A coating masking fixture for a turbine blade (10), the turbine blade (10) comprising a blade profile (101), a blade root (102), and a blade crown (103), the blade crown (103) comprising two contact surfaces for contacting other blade crowns, characterized in that, The coating masking fixture (100) includes: The clamp body (1) has a receiving space (S) for accommodating a portion of the turbine blade (10). The clamp body (1) is composed of a first base block (11) and a second base block (12). Each of the first base block (11) and the second base block (12) has a base block top wall, a base block bottom wall, and a base block side wall connecting the base block top wall and the base block bottom wall. The base block top wall, the base block bottom wall, and the base block side wall form a U-shaped groove. When the first base block (11)... 1) When connected together with the second base block (12) to form the clamp body (1), the opening directions of the U-shaped grooves of the first base block (11) and the second base block (12) are opposite to each other, such that the clamp body (1) has a first opening on a first side (1a) and a second opening on a second side (1b) opposite to the first side (1a), and such that the two contact surfaces of the leaf crown (103) accommodated in the accommodating space (S) point to the first opening and the second opening respectively; and Two shielding panels (2) are respectively connected to the first side (1a) and the second side (1b) of the clamp body (1) to cover the first opening and the second opening. Feature holes (21) are provided on the shielding panels (2), the outline of the feature holes (21) corresponding to the outline of the corresponding contact surface of the leaf crown (103) and the feature holes (21) are aligned with each other.

2. The coating shielding fixture for turbine blades according to claim 1, characterized in that, The top walls of the first base block (11) and the second base block (12) form the top wall of the clamp body (1), and the bottom walls of the first base block (11) and the second base block (12) form the bottom wall of the clamp body (1). A threaded through hole (H) is provided on the top wall of the clamp body (1), and a through groove (G) is provided on the bottom wall of the clamp body (1) for the blade root (102) of the turbine moving blade (10) to pass through.

3. The coating shielding fixture for turbine blades according to claim 2, characterized in that, The coating masking fixture (100) further includes a threaded rod (3) extending in a vertical direction, the threaded rod (3) being configured to engage with the threaded through hole (H) such that the threaded rod (3) can be screwed into and through the threaded through hole (H) to abut against the top surface of the crown (103) of the turbine blade (10) and the bottom surface of the airfoil (101) of the turbine blade (10) abut against the bottom wall of the fixture body (1), thereby clamping the turbine blade (10) in the vertical direction.

4. The coating masking fixture for turbine blades according to claim 3, characterized in that, The top and bottom walls of the clamp body (1) are flat and parallel to each other, and perpendicular to the extension direction of the threaded rod (3).

5. The coating masking fixture for turbine blades according to claim 4, characterized in that, The projection of the turbine blade (10) onto the top wall of the fixture body (1) in the vertical direction does not exceed the outline of the top wall.

6. The coating shielding fixture for turbine blades according to claim 1, characterized in that, The shielding panel (2) includes a flat feature section (22) with the feature hole (21) and an auxiliary section (23) without the feature hole (21).

7. The coating masking fixture for turbine blades according to claim 6, characterized in that, The contact surface of the crown (103) of the turbine blade (10) is flat and flush with the flat feature section (22) of the shielding plate (2) after the shielding plate (2) is connected to the clamp body (1).

8. The coating shielding fixture for turbine blades according to claim 1, characterized in that, The first base block (11) is provided with at least one first threaded hole (H1) on both the first side (1a) and the second side (1b), and the second base block (12) is provided with at least one second threaded hole (H2) on both the first side (1a) and the second side (1b).

9. The coating shielding fixture for turbine blades according to claim 8, characterized in that, One of the two shielding panels (2) is connected to the clamp body (1) by means of at least one first threaded hole (H1) and at least one second threaded hole (H2) on the first side (1a) and the corresponding screws, and the other of the two shielding panels (2) is connected to the clamp body (1) by means of at least one first threaded hole (H1) and at least one second threaded hole (H2) on the second side (1b) and the corresponding screws.

10. The coating masking fixture for turbine blades according to claim 2, characterized in that, A first step portion (11S) is provided at the edge of the top wall of the first base block (11) facing the second base block (12), and a first through hole (HA) is provided in the first step portion (11S). A second step portion (12S) is provided at the edge of the top wall of the second base block (12) facing the first base block (11), and a second through hole (HB) is provided in the second step portion (12S). The first base block (11) and the second base block (12) are connected to each other by means of the first step portion (11S) and the second step portion (12S), and the first through hole (HA) and the second through hole (HB) are aligned with each other to form the threaded through hole (H).

11. The coating masking fixture for turbine blades according to claim 2, characterized in that, The edge of the base wall of the first base block (11) facing the second base block (12) and the edge of the base wall of the second base block (12) facing the first base block (11) are spaced apart from each other to form the through groove (G).

12. The coating masking fixture for turbine blades according to claim 3, characterized in that, The coating masking fixture (100) further includes at least one lateral limiting member (4) disposed within the receiving space (S), the lateral limiting member (4) being configured to limit the positioning of the turbine blade (10) in the lateral direction perpendicular to the vertical direction by form-fitting.

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