Measuring tool for measuring designated measuring points on the blade root height surface of precision forged steam turbine blades

Abstract

The present invention provides a measuring tool for measuring designated measuring points on the blade root height surface of a precision forged steam turbine blade, which can solve the problem that the existing height gauge is not accurate when measuring the blade root height surface of a precision forged steam turbine blade, and the use of three-coordinate measurement will occupy the three-coordinate measurement capacity of the enterprise. The measuring tool comprises an inner arc measuring plate and a back arc measuring plate respectively arranged on both sides of the inner back of the precision forged blade and arranged in a coplanar manner, the inner arc measuring plate and the back arc measuring plate are arranged above the blade root height surface of the precision forged blade, and mounting holes are respectively provided on the inner arc measuring plate and the back arc measuring plate corresponding to the designated measuring points and reference points on the blade root height surface, and an ejector sleeve assembly is installed in the mounting hole, and an ejector sleeve assembly is installed with an ejector that can move upward, and the length of the ejector is designed according to the theoretical height of the corresponding designated measuring point or reference point; in a natural state, the top surface of the ejector is flush with the top surface of the ejector sleeve assembly, and the lower end of the ejector extends out of the ejector sleeve assembly.

Description

Technical Field

[0001] The invention relates to the field of processing and measuring of precision forged blades of steam turbines, in particular to a measuring tool for measuring a designated measuring point on a blade root height surface of a precision forged blade of a steam turbine. Background Art

[0002] For the precision forged turbine blades, only the blade body profile and blade root height surface are processed when delivered, and the other surfaces are in the blank state. For the inspection of the blade body profile, the profile frame measuring tool is usually used in conjunction with the profile measurement template for measurement, and for the inspection of the blade root height surface, since the blade root height surface 1 is a circular arc surface, such as Figure 1 and Figure 2 As shown, the heights of four designated measuring points MP1, MP2, MP3, and MP4 on the blade root height plane relative to the reference point AP on the plane are usually measured. In the past, either a height gauge or a three-coordinate measurement center was used. The former cannot accurately determine the positions of the designated measuring points, and the measurement accuracy is not high. Although the latter has high measurement accuracy, it will occupy the company's three-coordinate measurement capacity. Summary of the invention

[0003] In view of the technical problems that the measurement accuracy of the existing height gauge used in measuring the root height surface of the precision forged steam turbine blade is low, and the use of three-coordinate measurement will occupy the three-coordinate measurement production capacity of the enterprise, the present invention provides a measuring tool for measuring the specified measuring point on the root height surface of the precision forged steam turbine blade, which can achieve accurate measurement of the height of the specified measuring point on the root height surface relative to the reference point on the surface without using three-coordinate measurement.

[0004] The technical solution is as follows: a measuring tool for measuring designated measuring points on the blade root height surface of a precision forged blade of a steam turbine, characterized in that it comprises an inner arc measuring plate and a back arc measuring plate respectively arranged on both sides of the inner back of the precision forged blade and arranged in a coplanar manner, the inner arc measuring plate and the back arc measuring plate being arranged above the blade root height surface of the precision forged blade, the inner arc measuring plate and the back arc measuring plate being respectively provided with mounting holes corresponding to designated measuring points and reference points on the blade root height surface, an ejector sleeve assembly being installed in the mounting hole, an ejector sleeve assembly being installed with an ejector that can move upward, the length of the ejector being designed according to the theoretical height of the corresponding designated measuring point or reference point; in a natural state, the top end surface of the ejector is flush with the top end surface of the ejector sleeve assembly, and the lower end of the ejector extends out of the ejector sleeve assembly.

[0005] It is further characterized by:

[0006] The ejector sleeve assembly includes a fixing sleeve and a pin sleeve. The fixing sleeve is located above the inner arc measuring plate or the back arc measuring plate. The fixing sleeve is provided with a circular through hole 1, a circular through hole 2 and a threaded hole coaxially arranged from top to bottom. The pin sleeve includes a threaded section, a cylindrical section 1 and a cylindrical section 2 coaxially arranged from top to bottom, and the pin sleeve is provided with a central axis hole. The cylindrical section 1 is inserted into the mounting hole and the threaded section is screwed with the threaded hole, so that the inner arc measuring plate or the back arc measuring plate is clamped between the fixing sleeve and the pin sleeve. The cylindrical section 2 is between the cylindrical section 3; the ejector pin includes a coaxially arranged cylindrical section 3, a step, a cylindrical section 4 and a top from top to bottom, the cylindrical section 3 is gap-matched with the circular through hole 1, the step is gap-matched with the circular through hole 2, the cylindrical section 4 is gap-matched with the central axis hole, a spring is sleeved on the cylindrical section 3, the upper end of the spring abuts against the top surface of the circular through hole 2, the lower end abuts against the top surface of the step, and the bottom surface of the step abuts against the top end surface of the pin sleeve; the top extends out of the pin sleeve.

[0007] The vertical distance between the bottom surface of the step and the tip of the top is designed according to the upper tolerance of the theoretical height of the corresponding designated measuring point or reference point.

[0008] The beneficial effects of the present invention are:

[0009] The measuring tool for measuring the designated measuring points on the blade root height surface of a precision forged steam turbine blade of the present invention comprises an inner arc measuring plate and a back arc measuring plate, on which ejector sleeve assemblies and ejectors are respectively installed corresponding to four designated measuring points and reference points on the inner arc measuring plate and the back arc measuring plate. During measurement, the inner arc measuring plate and the back arc measuring plate are placed on the gear block of the profile frame measuring tool with the aid of an existing profile frame measuring tool, the precision forged steam turbine blade is clamped on the profile frame measuring tool, and the clamping height of the precision forged steam turbine blade is adjusted until the ejector at the reference point in the measuring tool contacts the blade root height surface and the ejector tops the blade. The end face is flush with the top end face of the ejector sleeve assembly. At this time, the measurement state of the turbine precision forging blade is adjusted in place, and then the height value of the ejector top protruding from the top end face of the ejector sleeve assembly at the four designated measuring points can be measured, that is, the height of the four designated measuring points relative to the reference point. According to the measured protruding height values, it can be judged whether the height of the four designated measuring points of the blade can meet the requirements. This measuring tool can accurately measure the relative height of the designated measuring points and effectively release the company's three-coordinate production capacity; this measuring tool is easy and quick to use, and one person can complete the measurement of the blade root height surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the dimensions of the blade root height surface of the precision forged steam turbine blade and each designated measuring point and reference point on the surface;

[0011] Figure 2 for Figure 1 A top view of

[0012] Figure 3 A top view of the inner arc measurement plate and the back arc measurement plate of the present invention;

[0013] Figure 4 It is a schematic diagram of the installation of the ejector sleeve assembly and the ejector at the installation hole of the present invention;

[0014] Figure 5 It is a main cross-sectional view of the fastening sleeve of the present invention;

[0015] Figure 6 is a main cross-sectional view of the pin sleeve of the present invention;

[0016] Figure 7 is a front view of the ejector pin of the present invention;

[0017] Figure 8 It is a schematic diagram of the use state of the measuring tool of the present invention on the profile frame measuring tool;

[0018] Fig. 9 for Figure 8 Magnified view of area A.

[0019] Figure markings: 1-blade root height surface; 2-inner arc measuring plate; 3-back arc measuring plate; 4-mounting hole; 5-thimble; 6-fastening sleeve; 7-pin sleeve; 8-spring; 9-profile frame measuring tool; 10-shift block; 11-precision forged blade; 51-cylindrical segment three; 52-step; 53-cylindrical segment four; 54-top; 61-circular through hole one; 62-circular through hole two; 63-threaded hole; 71-threaded segment; 72-cylindrical segment one; 73-cylindrical segment two; 74-center axis hole. DETAILED DESCRIPTION

[0020] See Figures 1 to 9 The measuring tool for measuring the designated measuring points on the blade root height surface of a precision forged blade of a steam turbine of the present invention comprises an inner arc measuring plate 2 and a back arc measuring plate 3 which are respectively arranged on both sides of the inner back of the precision forged blade and are arranged in a coplanar manner. The inner arc measuring plate 2 and the back arc measuring plate 3 are arranged above the blade root height surface 1 of the precision forged blade. The inner arc measuring plate 2 and the back arc measuring plate 3 are respectively provided with mounting holes 4 corresponding to the designated measuring points MP1, MP2, MP3, MP4 and the reference point AP on the blade root height surface 1. Figure 3As shown, the mounting holes 4 on the inner arc measurement plate 2 correspond to the designated measuring point MP1, the reference point AP, and the designated measuring point MP3 from left to right, and the mounting holes 4 on the back arc measurement plate 3 correspond to the designated measuring points MP2 and MP4 from left to right; an ejector sleeve assembly is installed in the mounting hole 4, and an ejector 5 capable of moving upward is installed in the ejector sleeve assembly, and the length of the ejector 5 is designed according to the theoretical height of the corresponding designated measuring points MP1, MP2, MP3, MP4 or the reference point AP; in the natural state, the top surface of the ejector 5 is flush with the top surface of the ejector sleeve assembly, and the lower end of the ejector 5 extends out of the ejector sleeve assembly.

[0021] See Figures 4 to 7 The ejector sleeve assembly includes a fixing sleeve 6 and a pin sleeve 7. The fixing sleeve 6 is located above the inner arc measuring plate 2 or the back arc measuring plate 3. The fixing sleeve 6 is provided with a coaxially arranged circular through hole 1 61, a coaxially arranged circular through hole 2 62 and a threaded hole 63 from top to bottom; the pin sleeve 7 includes a coaxially arranged threaded section 71, a cylindrical section 1 72 and a cylindrical section 2 73 from top to bottom, and the pin sleeve 7 is provided with a central axis hole 74; the cylindrical section 1 72 is inserted into the mounting hole 4 and the threaded section 71 is screwed with the threaded hole 63, so that the inner arc measuring plate 2 or the back arc measuring plate 3 is clamped between the fixing sleeve 6 and The ejector pin 5 comprises, from top to bottom, a coaxially arranged cylindrical section three 51, a step 52, a cylindrical section four 53 and a top point 54, the cylindrical section three 51 is clearance-matched with the circular through hole one 61, the step 52 is clearance-matched with the circular through hole two 62, the cylindrical section four 53 is clearance-matched with the central axis hole 74, a spring 8 is sleeved on the cylindrical section three 51, the upper end of the spring 8 abuts against the top surface of the circular through hole two 62, the lower end abuts against the top surface of the step 52, the bottom surface of the step 52 abuts against the top surface of the pin sleeve 7; the top point 54 extends out of the pin sleeve 7. During installation, firstly, the spring 8 is mounted on the cylindrical section 3 51 of the ejector pin 5, and then the ejector pin 5 and the spring 8 are installed into the fixing sleeve 6, and then passed through the mounting hole 4, and finally the pin sleeve 7 is tightened. After the pin sleeve 7 is tightened, under the action of the spring 8, the bottom surface of the step 52 abuts against the top surface of the pin sleeve 7, and then the top surfaces of the fixing sleeve 6 and the ejector pin 5 are leveled.

[0022] In order to ensure that after the measurement state of the precision forged blade of the steam turbine is adjusted in place, the ejectors at the four designated measurement points can all protrude from the fixing sleeve, the vertical distance C between the bottom surface of the step 52 and the tip of the tip 54 is designed according to the upper tolerance of the theoretical height of the corresponding designated measurement point or reference point, and the total length B of the ejector 5 is also designed according to the upper tolerance of the theoretical height of the corresponding designated measurement point or reference point. For example, the theoretical height of the reference point AP is 38.6mm, the theoretical height of the designated measurement point MP1 is 39.6±0.65mm, the theoretical height of the designated measurement point MP2 is 42±0.65mm, and the theoretical height of the designated measurement point MP3 is 48.7±0.65mm. -0.65 0, the theoretical height of the designated measuring point MP4 is 36.6±0.65mm, then the C value and B value of the ejector pin at each designated measuring point and reference point are designed according to the following formula, see Table 1 for details.

[0023] Among them, C value = theoretical height of each point + upper tolerance + a; B value = C value + b; a and b are both constants. In Table 1, a is 11mm and b is 16.5mm.

[0024] Table 1 Design of C and B values ​​of ejector pins at designated measuring points and reference points

[0025]

[0026] The following is a detailed description of the process of measuring the specified measuring points on the root height surface of the turbine precision forged blade using the measuring tool of the present invention: the inner arc measuring plate 2 and the back arc measuring plate 3 are placed on the gear block 10 of the profile frame measuring tool 9, the turbine precision forged blade 11 is clamped on the profile frame measuring tool 9, and the clamping height of the turbine precision forged blade 11 is adjusted until the ejector pin 5 at the reference point AP in the measuring tool contacts the blade root height surface 1 and the top end surface of the ejector pin 5 is flush with the top end surface of the fixing sleeve 6. At this time, the measuring state of the turbine precision forged blade 11 is adjusted into place, and then the height values ​​of the top of the ejector pin 5 protruding from the top end surface of the fixing sleeve 6 at the four specified measuring points MP1, MP2, MP3, and MP4 are measured respectively, which are the heights of the four specified measuring points relative to the reference points.

Claims

1. A measuring tool for measuring a specified measuring point on the root height plane of a precision forged steam turbine blade, characterized in that: It comprises an inner arc measuring plate and a back arc measuring plate which are respectively arranged on both sides of the inner back of the precision forged blade and are arranged in the same plane. The inner arc measuring plate and the back arc measuring plate are arranged above the blade root height surface of the precision forged blade. The inner arc measuring plate and the back arc measuring plate are respectively provided with mounting holes corresponding to four designated measuring points and one reference point on the blade root height surface. An ejector sleeve assembly is installed in the mounting hole. An ejector which can move upward is installed in the ejector sleeve assembly. The length of the ejector is designed according to the theoretical height of the corresponding designated measuring point or reference point. In the natural state, the top end surface of the ejector is flush with the top end surface of the ejector sleeve assembly. The lower end extends out of the ejector sleeve assembly. During measurement, with the help of the existing profile frame measuring tool, the inner arc measuring plate and the back arc measuring plate are placed on the gear block of the profile frame measuring tool, and the turbine precision forging blade is clamped on the profile frame measuring tool. The clamping height of the turbine precision forging blade is adjusted until the ejector at the reference point of the measuring tool contacts the blade root height surface and the top end surface of the ejector is flush with the top end surface of the ejector sleeve assembly. At this time, the measurement state of the turbine precision forging blade is adjusted in place, and then the height value of the ejector top at the four designated measuring points protruding from the top end surface of the ejector sleeve assembly is measured, which is the height of the four designated measuring points relative to the reference point.

2. The measuring tool for measuring the designated measuring point on the root height plane of a precision forged blade of a steam turbine according to claim 1, characterized in that: The ejector sleeve assembly includes a fixing sleeve and a pin sleeve. The fixing sleeve is located above the inner arc measuring plate or the back arc measuring plate. The fixing sleeve is provided with a circular through hole 1, a circular through hole 2 and a threaded hole coaxially arranged from top to bottom. The pin sleeve includes a threaded section, a cylindrical section 1 and a cylindrical section 2 coaxially arranged from top to bottom, and the pin sleeve is provided with a central axis hole. The cylindrical section 1 is inserted into the mounting hole and the threaded section is screwed with the threaded hole, so that the inner arc measuring plate or the back arc measuring plate is clamped between the fixing sleeve and the pin sleeve. The cylindrical section 2 is between the cylindrical section 3; the ejector pin includes a coaxially arranged cylindrical section 3, a step, a cylindrical section 4 and a top from top to bottom, the cylindrical section 3 is gap-matched with the circular through hole 1, the step is gap-matched with the circular through hole 2, the cylindrical section 4 is gap-matched with the central axis hole, a spring is sleeved on the cylindrical section 3, the upper end of the spring abuts against the top surface of the circular through hole 2, the lower end abuts against the top surface of the step, and the bottom surface of the step abuts against the top end surface of the pin sleeve; the top extends out of the pin sleeve.

3. The measuring tool for measuring the designated measuring point on the root height plane of a precision forged steam turbine blade according to claim 2, characterized in that: The vertical distance between the bottom surface of the step and the tip of the top is designed according to the upper tolerance of the theoretical height of the corresponding designated measuring point or reference point.

Images