Clamping device for machining large blade with thermal power bent blade root

Abstract

The utility model relates to the technical field of large blade clamping, in particular to a clamping device for machining a thermal power bent blade root large blade, which aims to solve the problem that an existing steam turbine blade clamping device can only clamp a straight blade root blade and cannot clamp a bent blade root blade, and comprises a clamping disc and a plurality of ejector pin clamping mechanisms, the ejector pin clamping mechanisms are fixed to the upper end face of the clamping disc, and every two adjacent ejector pin clamping mechanisms are arranged in an inclined mode. The ejector pin clamping mechanism comprises a sliding rail, a center table, an ejector pin, a clamping jaw, a two-way screw and a limiting boss. A center table is arranged in the center of the sliding rail, an ejector pin is installed at the upper end of the center table, two clamping jaws are connected to the sliding rail in a sliding mode, the two-way screw penetrates through the center table, threads on the two sides of the two-way screw are in threaded connection with the two clamping jaws respectively, and a limiting boss is arranged at the upper end of the sliding rail.

Description

Technical Field

[0001] This utility model relates to the field of large blade clamping technology, and in particular to a clamping device for processing large blades at the curved root of thermal power plants. Background Technology

[0002] Steam turbine blades are key components of steam turbines, primarily used to convert the thermal energy of steam into mechanical energy. They are mounted on the rotor; as steam passes through the blades, it drives the rotor to rotate, thereby powering generators or other equipment. Steam turbine blades require high machining precision, necessitating specialized fixtures to support the machining process. Casting square boxes is one common method. These boxes are made of Babbitt alloy, casting a square fixing part in the middle of the blade to facilitate machining the blade root. However, the cast square box method is cumbersome, requiring machining of the blade root teeth after casting, followed by disassembly of the box and machining of the air passages. Therefore, pin clamps are now commonly used to fix the blades.

[0003] Utility model patent CN202212779U discloses a mechanically centering clamping blade fixture. It features a reference center for holding the blade positioning hole and two clamping blocks that can move centripetally and clamp the blade processing table. During clamping, the reference center is held against the blade positioning hole, and the clamping blocks are tightened, clamping the blade processing table between the clamping blocks, thus completing the blade clamping. This eliminates the need for the Babbitt alloy casting method in the blade root tooth profile machining process, saving the steps of casting and disassembling the casting box. It allows multiple machining surfaces of the turbine blade, such as the air passage and blade root tooth profile, to be processed on the same machine tool, saving machining time and reducing the use of Babbitt alloy.

[0004] Steam turbine blades can be classified into straight-root blades and curved-root blades according to the shape of their blade roots. However, the aforementioned clamping device can only clamp straight-root blades and cannot achieve a stable clamping effect on curved-root blades. Utility Model Content

[0005] In order to solve the problem that existing turbine blade clamping devices can only clamp straight root blades and cannot clamp curved root blades, this utility model provides a clamping device for processing large curved root blades for thermal power plants, thereby solving the problems mentioned in the background art.

[0006] The technical solution of this utility model is:

[0007] A clamping device for processing large blades at the root of curved blades in thermal power plants includes a clamping plate and several ejector pin clamping mechanisms. The ejector pin clamping mechanisms are fixed to the upper end face of the clamping plate, and adjacent ejector pin clamping mechanisms are arranged at an angle.

[0008] The ejector clamping mechanism includes a slide rail, a center platform, an ejector pin, grippers, a bidirectional screw, and a limiting boss. The center platform is located at the center of the slide rail, and the ejector pin is installed at the upper end of the center platform. Two grippers are slidably connected on the slide rail. The bidirectional screw passes through the center platform, and the threads on both sides of the bidirectional screw are threadedly connected to the two grippers respectively. A limiting boss is provided at the upper end of the slide rail.

[0009] Furthermore, the slide rail is provided with a raised groove, and the lower end of the gripper is provided with a raised slider, which is slidably connected in the raised groove on the slide rail.

[0010] Furthermore, the ejector pin clamping mechanism consists of two parts, with the slide rails fixed to the clamping plate by welding.

[0011] Furthermore, the included angle between the adjacent ejector pin clamping mechanisms is 15°-30°.

[0012] Furthermore, the gripping surface of the gripper is equipped with toothed clamping teeth.

[0013] Furthermore, the teeth of the toothed clamp are detachably connected to the jaws via bolts.

[0014] Furthermore, both ends of the bidirectional screw are provided with hexagonal holes.

[0015] Furthermore, the ejector pin is fixed to the center platform by welding.

[0016] Furthermore, the ejector pin is made of chrome vanadium steel.

[0017] Furthermore, the clamping plate is provided with multiple clamping plate fixing grooves in the circumferential direction.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1. A clamping device for processing large blades with curved blade roots in thermal power plants, used for clamping the curved blade root end, is provided with two pin clamping mechanisms, two positioning holes are opened at the blade root, the pins in the pin clamping mechanism are inserted into the positioning holes on the blade root, and the blade crown is fixed by a single pin clamping mechanism, thereby realizing the clamping of the curved blade root.

[0020] 2. This clamping device uses double pins to fix the bent blade root. It can fix bent blade roots of different sizes. Equipped with a bidirectional screw and two grippers, tightening the bidirectional screw brings the two grippers closer together, fixing the side wall of the bent blade root and preventing it from detaching from the pins. Because the blade root uses two-point positioning clamping, for bent blade roots of different sizes, only two equidistant positioning holes need to be made on the blade root to fix the bent blade roots of different sizes. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the clamping device.

[0022] Figure 2 This is a top view of the clamping device;

[0023] Figure 3 This is a schematic diagram of the ejector pin clamping mechanism;

[0024] Figure 4 This is the front view of the ejector pin clamping mechanism;

[0025] Figure 5 Exploded view of the ejector pin clamping mechanism;

[0026] Figure 6 This is a longitudinal sectional view of the ejector pin clamping mechanism;

[0027] Figure 7 This is a side view of the ejector pin clamping mechanism;

[0028] Figure 8 This is a schematic diagram of the gripper structure.

[0029] In the diagram: 1. Clamping plate; 201. Slide rail; 202. Center platform; 203. Ejector pin; 301. Clamping jaw; 4. Bidirectional screw; 204. Limiting boss; 205. Raised groove; 302. Raised slider; 5. Toothed clamp teeth; 6. Hexagonal hole; 7. Clamping plate fixing groove. Detailed Implementation

[0030] Specific implementation method one: See Figure 3-7 As shown, a clamping device for processing large blades at the root of curved blades in thermal power plants is provided. This embodiment includes a clamping plate 1 and several ejector pin clamping mechanisms. The ejector pin clamping mechanisms are fixed on the upper end face of the clamping plate 1, and adjacent ejector pin clamping mechanisms are arranged in an inclined manner.

[0031] The ejector clamping mechanism includes a slide rail 201, a center platform 202, an ejector pin 203, grippers 301, a bidirectional screw 4, and a limiting boss 204. The center platform 202 is located at the center of the slide rail 201, and the ejector pin 203 is installed at the upper end of the center platform 202. Two grippers 301 are slidably connected to the slide rail 201. The bidirectional screw 4 passes through the center platform 202, and the threads on both sides of the bidirectional screw 4 are threadedly connected to the two grippers 301 respectively. The limiting boss 204 is provided at the upper end of the slide rail 201.

[0032] Furthermore, the slide rail 201 is a single integrated structure, with the center platform 202 fixed to the center of the slide rail 201 by welding. A circular hole is provided on the center platform 202, through which the bidirectional screw 4 passes, allowing it to rotate within the center platform 202 and slide left and right relative to it. This allows the two grippers 301 to slide synchronously to the left or right relative to the center platform 202. The two grippers 301 are symmetrically arranged relative to the center platform 202, each with a through-hole threaded hole. With the center platform 202 as a reference, the threads on the left and right grippers 301 rotate in opposite directions. The threads on both sides of the bidirectional screw 4 are threaded into the threads on the two grippers 301. This allows the two grippers 301 to move closer or further apart when the bidirectional screw 4 is rotated. When the bidirectional screw 4 is rotated clockwise, the two grippers 301 move closer together to clamp the bent blade root; when the bidirectional screw 4 is rotated counterclockwise, the two grippers 301 move further apart to release the bent blade root. The ejector pin 203 is fixed to the center of the upper end of the center platform 202 by embedding or welding. As an alternative implementation, the ejector pin 203 is integrally formed with the center platform 202. The limiting boss 204 is used to limit the grippers 301.

[0033] As an alternative implementation, the bidirectional screw 4 has a shoulder and a retaining ring in its middle section. The shoulder and retaining ring abut against the left and right sides of the center platform 202, respectively, preventing the bidirectional screw 4 from sliding relative to the center platform 202 in its circumferential direction, thus forming a self-centering clamp. The bidirectional screw 4 can only rotate within the center platform 202, and the two grippers 301 are equidistant from the center platform 202. Rotating the bidirectional screw 4 causes the two grippers 301 to move closer and further away from the center platform 202 at equal distances.

[0034] Specific Implementation Method Two: See Figure 3-7 As shown, the slide rail 201 of this embodiment has a raised groove 205, and the lower end of the gripper 301 is provided with a raised slider 302, which is slidably connected in the raised groove 205 on the slide rail 201.

[0035] Furthermore, the raised groove 205 in the slide rail 201 and the raised slider 302 at the lower end of the gripper 301 are both machined by milling. The lower end of the center platform 202 has the same structure as the raised slider 302. After the center platform 202 slides into the slide rail 201, it is fixed by welding. The slide rail 201 and the center platform 202 are machined separately to facilitate the machining of the raised groove 205 in the slide rail 201. The shapes of the raised groove 205 and the raised slider 302 are similar to raised characters. The bidirectional screw 4 is located in the raised groove 205 in the slide rail 201, and the screw hole on the gripper 301 is opened on the raised slider 302.

[0036] This clamping device uses double pins to fix the bent blade root. Two positioning holes are made at the blade root. The pins 203 in the pin clamping mechanism are inserted into the positioning holes on the blade root. Tightening the bidirectional screw 301 brings the two jaws 301 closer together, fixing the side wall of the bent blade root and preventing the blade root from coming out of the pins. Because the blade root is clamped at two points, for bent blade roots of different sizes, only two equidistant positioning holes need to be made on the blade root to fix blade roots of different sizes.

[0037] Specific implementation method three: See Figure 1-2 As shown, the ejector pin clamping mechanism in this embodiment consists of two parts, and the slide rail 201 is fixed to the clamping plate 1 by welding.

[0038] Detailed Implementation Method Four: See [link] Figure 1-2 As shown, the included angle between adjacent ejector pin clamping mechanisms in this embodiment is 15°-30°.

[0039] Furthermore, the slide rail 201 is fixed to the clamping plate 1 by welding. As an alternative implementation, the lower end of the slide rail 201 is provided with a screw hole, and a bolt passes through the clamping plate 1 to fix the slide rail 201 to the clamping plate 1. The axes of the bidirectional screws 4 in the two ejector clamping mechanisms are at an angle of 15°-30° relative to each other, and the ejector pins 203 in the two ejector clamping mechanisms are on the same arc relative to this center.

[0040] Specific implementation method five: See Figure 8 As shown, the gripper 301 of this embodiment has toothed clamp teeth 5 installed on its gripping surface.

[0041] Specific implementation method six: See Figure 8 As shown, in this embodiment, the toothed clamp teeth 5 are detachably connected to the jaws 301 by bolts.

[0042] Furthermore, the toothed jaw 5 protrudes beyond the end face of the gripper 301, and the toothed jaw 5 is used to increase the friction between the gripper and the blade root. A through hole is provided on the toothed jaw 5, and a threaded hole is provided on the gripper 301. A bolt passes through the toothed jaw 5 and is threadedly connected to the gripper 301, thus detachably fixing the toothed jaw 5 and the gripper 301.

[0043] Detailed implementation method seven: See Figure 7 As shown, both ends of the bidirectional screw 4 in this embodiment are provided with hexagonal holes 6.

[0044] Furthermore, a hexagonal hole 6 is provided to facilitate the rotation of the bidirectional screw 4 during operation.

[0045] Detailed Implementation Method Eight: See also Figure 3As shown, in this embodiment, the ejector pin 203 is fixed to the center platform 202 by welding.

[0046] Detailed implementation method nine: See Figure 3 As shown, the ejector pin 203 in this embodiment is made of chrome vanadium steel.

[0047] Furthermore, the ejector pin 203 is made of chrome vanadium steel, which can reduce the wear of the ejector pin 203.

[0048] Detailed Implementation Method Ten: See [link] Figure 1-2 As shown, the clamping plate 1 in this embodiment has a plurality of clamping plate fixing grooves 7 circumferentially.

[0049] Furthermore, the clamping plate fixing groove 7 is used for fixed connection with the worktable or machine tool spindle.

[0050] In use, two positioning holes are made at the curved root of the blade, and the pin 203 in the pin clamping mechanism is inserted into the positioning hole on the root of the blade. The blade crown is fixed by a single pin clamping mechanism, thereby realizing the clamping of the curved root of the blade.

[0051] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A clamping device for processing large blades at the root of bent blades in thermal power plants, characterized in that: It includes a clamping plate (1) and several ejector pin clamping mechanisms. The ejector pin clamping mechanisms are fixed on the upper end face of the clamping plate (1), and adjacent ejector pin clamping mechanisms are arranged in an inclined manner. The ejector clamping mechanism includes a slide rail (201), a center platform (202), an ejector pin (203), grippers (301), a bidirectional screw (4), and a limiting boss (204). The center platform (202) is located at the center of the slide rail (201), and the ejector pin (203) is installed at the upper end of the center platform (202). Two grippers (301) are slidably connected on the slide rail (201). The bidirectional screw (4) passes through the center platform (202), and the threads on both sides of the bidirectional screw (4) are threadedly connected to the two grippers (301) respectively. A limiting boss (204) is provided at the upper end of the slide rail (201).

2. The clamping device for processing large blades at the root of bent blades in thermal power plants according to claim 1, characterized in that: The slide rail (201) has a raised groove (205), and the lower end of the gripper (301) is provided with a raised slider (302), which is slidably connected in the raised groove (205) on the slide rail (201).

3. The clamping device for processing large blades at the root of bent blades in thermal power plants according to claim 1, characterized in that: The ejector pin clamping mechanism consists of two parts, with the slide rail (201) fixed to the clamping plate (1) by welding.

4. The clamping device for processing large blades at the root of bent blades in thermal power plants according to claim 1, characterized in that: The included angle between the adjacent ejector pin clamping mechanisms is 15°-30°.

5. The clamping device for processing large blades at the root of bent blades in thermal power plants according to claim 1, characterized in that: The gripping surface of the gripper (301) is equipped with toothed gripper teeth (5).

6. The clamping device for processing large blades at the root of bent blades in thermal power plants according to claim 5, characterized in that: The toothed clamp teeth (5) are detachably connected to the jaws (301) by bolts.

7. The clamping device for processing large blades at the root of bent blades in thermal power plants according to claim 1, characterized in that: Both ends of the bidirectional screw (4) are provided with hexagonal holes (6).

8. The clamping device for processing large blades at the root of bent blades in thermal power plants according to claim 1, characterized in that: The ejector pin (203) is fixed to the center platform (202) by welding.

9. The clamping device for processing large blades at the root of bent blades in thermal power plants according to claim 1, characterized in that: The ejector pin (203) is made of chrome vanadium steel.

10. The clamping device for processing large blades at the root of bent blades in thermal power plants according to claim 1, characterized in that: The clamping plate (1) has multiple clamping plate fixing grooves (7) circumferentially.

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