Method for measuring profile tolerance of arc surface on middle shell of turbine shell

Abstract

The invention relates to a method for measuring the profile tolerance of an arc surface on a middle shell of a turbine shell. The method comprises the following steps: providing a measurement gauge, wherein the measurement gauge comprises a positioning pin, a go-no go gauge and a positioning pin handle; the positioning pin comprises a positioning pin center hole, and the positioning pin handle is connected to the positioning pin center hole; the outer contour of the positioning pin comprises three concyclic positioning pin arcs and positioning pin straight edges connected between the adjacent positioning pin arcs; a sliding fit hole is vertically formed along the surface of the positioning pin; the go / no-go gauge comprises a go / no-go gauge handle, a sliding column and a go / no-go gauge body which are connected in sequence; the position of the positioning pin is adjusted through a positioning pin handle, and the positioning pin is inserted into the datum hole; vertically moving a go / no-go gauge handle, and judging whether the profile tolerance size of the arc surface to be measured is qualified or not by observing the passing or stopping conditions of the go gauge and the no-go gauge on the arc surface; and the measurement of other arc surfaces is completed. And on-site rapid determination of the profile tolerance of the arc surface on the middle shell of the turbine shell is realized.

Description

Technical Field

[0001] The invention relates to the technical field of turbine casing detection, in particular to a method for measuring the contour of an arc surface on a turbine casing intermediate casing. Background Art

[0002] The turbine housing is the transitional element connecting the exhaust pipe and the intermediate housing, and also serves as a protective cover for the alloy impeller. Due to its complex shape, the turbine housing requires extremely high dimensional accuracy and surface quality, especially the requirements for the size tolerance and position accuracy of the turbine housing's holes.

[0003] During the machining of the turbine housing intermediate shell, refer to Figure 5 、 Figure 6 As shown, the turbine housing body is equipped with a turbine housing intermediate housing. Distributed circumferentially along the center hole of the turbine housing intermediate housing are multiple (e.g., five) radially outwardly projecting arc surfaces. Each arc surface has a profile tolerance requirement of 0.3mm relative to datum surface A, datum hole C, and datum surface D to ensure proper assembly, fit, or functionality of the workpiece. During machining of these arc surfaces, tool wear during use can easily lead to dimensional deviations at this location on the workpiece. Previously, these dimensions were typically sent to an inspection lab for verification using three-dimensional coordinate measuring equipment, without dedicated on-site inspection fixtures for process control.

[0004] Since CMM inspection on the production line typically involves first- and last-piece inspection, any dimensional deviations that occur during the inspection process often result in the batch being scrapped. Furthermore, CMM measurement cycles are lengthy, requiring parts to be sent to a dedicated inspection room, where they must wait for inspection. Once the inspection is complete, the results must be fed back to the production site. This process is time-consuming and prevents real-time monitoring and rapid response.

[0005] Therefore, there is an urgent need to provide a method for measuring the contour of the arc surface on the turbine housing intermediate shell, so as to quickly determine whether the size is qualified at the production site and ensure the quality control of the production process. Summary of the Invention

[0006] Therefore, the technical problem to be solved by the present invention is to overcome the problem in the prior art that the measurement quality of the arc surface on the volute intermediate shell cannot be guaranteed by three-coordinate measurement.

[0007] To solve the above technical problems, the present invention provides a method for measuring the contour of an arc surface on a turbine housing intermediate shell. A turbine housing intermediate shell is provided on a turbine housing body. A plurality of radially outwardly convex arc surfaces are distributed circumferentially along a center hole of the turbine housing intermediate shell. The turbine housing intermediate shell has a plurality of annular steps concentrically arranged with the center hole of the intermediate shell in a direction away from the center hole of the turbine housing body. The measuring method comprises: S1. Provide a measuring fixture, which includes a positioning pin, a go / no-go gauge, and a positioning pin handle; The positioning pin is adapted to be positioned on the uppermost annular step, and the uppermost annular step is defined as a reference hole, and the positioning pin comprises a positioning pin center hole, and a positioning pin handle is connected to the positioning pin center hole; The outer contour of the positioning pin comprises three positioning pin arcs which are uniformly distributed and coaxial along the positioning pin center hole, and a positioning pin straight edge which is connected between adjacent positioning pin arcs; A sliding fit hole is vertically arranged along the surface of the positioning pin, and the sliding fit hole is close to the positioning pin straight edge, and the common symmetry axis of the positioning pin straight edge and the positioning pin arc passes through the diameter of the sliding fit hole; The go-no-go gauge comprises a go-no-go gauge handle, a sliding column and a go-no-go gauge body which are sequentially connected, the sliding column is adapted to slide along the sliding fit hole, the go-no-go gauge body comprises a go gauge and a no-go gauge which are coaxially arranged and in the form of a disc, the no-go gauge is close to the sliding column relative to the go gauge, and the go-no-go gauge body partially protrudes from the positioning pin straight edge; S2, the position of the positioning pin is adjusted through the positioning pin handle, the positioning pin is inserted into the reference hole, the end face of the positioning pin is attached to the uppermost annular step, and the go-no-go gauge body is coaxially arranged with the arc surface to be measured, and the center positioning is completed; S3, the go-no-go gauge handle is vertically moved, and the go-no-go gauge is vertically moved downwards along the sliding fit hole to the arc surface to be measured, and whether the profile size of the arc surface to be measured is qualified is judged by observing the passing or stopping of the go gauge and the no-go gauge on the arc surface; S4, the positioning pin is taken out, the positioning pin handle is rotated, and the steps S2 to S3 are repeated to complete the measurement of the remaining arc surfaces.

[0008] In an embodiment of the present application, the outer diameter of the positioning pin is configured according to the lower deviation of the hole diameter of the reference hole.

[0009] In an embodiment of the present application, the outer diameter of the positioning pin is mm.

[0010] In an embodiment of the present application, the center position of the sliding fit hole is determined by the intersection of the common symmetry axis and the circle with the reference hole as the center and a diameter of 50.7mm.

[0011] In an embodiment of the present application, the theoretical diameter of the arc surface is 36.00±0.20mm, and the sizes of the go gauge and the no-go gauge are mm and mm respectively.

[0012] In one embodiment of the present application, a locking hole is arranged radially along the positioning pin and communicates with the sliding hole, and the locking hole is used to connect a locking screw which can abut against an axial locking groove arranged on the sliding column to limit the sliding of the sliding column.

[0013] In one embodiment of the present application, anti-skid knurls are arranged on the handle of the positioning pin and the handle of the go-no-go gauge.

[0014] In one embodiment of the present application, five circular arc surfaces are uniformly distributed circumferentially.

[0015] In one embodiment of the present application, the central hole of the positioning pin is a threaded hole, and the handle of the positioning pin is threadedly connected with the threaded hole.

[0016] The above technical scheme of the present application has the following advantages compared with the prior art: The method for measuring the profile of the circular arc surface on the intermediate shell of the turbine shell according to the present application can realize rapid on-site determination of the profile of the circular arc surface on the intermediate shell of the turbine shell by setting a measuring gauge, and the operation is simple, without the need to rely on a three-coordinate measuring device in a laboratory, so that the detection period is significantly shortened, and size deviations in the machining process can be found in time, thereby improving the quality control capability and response speed of the production site.

[0017] The measuring gauge according to the present application can ensure the repeatability and stability of the measuring process by center positioning with a special positioning pin in combination with a reference hole of a workpiece and by detection with a go-no-go gauge, and the sizes of the sliding hole, the go gauge and the stop gauge are customized according to the tolerances of the workpiece drawing, so that the reliability and consistency of the measurement results are effectively ensured.

[0018] The measuring gauge according to the present application has a simple structure and is convenient to manufacture and maintain, and is suitable for profile detection of circular arc surfaces of intermediate shells of turbine shells of different types or sizes. According to different specifications of workpieces, only the corresponding size of the positioning pin or the go-no-go gauge needs to be replaced, and the measuring gauge has good adaptability and promotional value.

[0019] The measuring method according to the present application adopts manual operation, and the operation is simple, and the operator does not need to have complex metrology knowledge and skills, and only needs to place and move the gauge according to the specified method, so that rapid detection of the profile of the circular arc surface can be accurately completed, and the measuring method is suitable for conventional detection requirements of a production site. Not only the use pressure of high-precision equipment such as a three-coordinate measuring instrument is reduced, but also detection resources and personnel investment are greatly saved, and the equipment utilization rate and operation efficiency of the production line as a whole are improved. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to make the content of the present application more easily understood, the present application will be further described in detail below according to specific embodiments of the present application and in combination with the drawings.

[0021] Figure 1 It is a schematic diagram of the overall structure of the measuring fixture of the present invention.

[0022] Figure 2 It is a structural schematic diagram of the positioning pin of the present invention.

[0023] Figure 3 It is a structural schematic diagram of the turbine shell body of the present invention.

[0024] Figure 4 It is a side view schematic diagram of the turbine shell body of the present invention.

[0025] Figure 5 yes Figure 4 Cross-sectional view along the AA direction.

[0026] Figure 6 It is a schematic diagram of the dimension marking of the turbine housing body of the present invention.

[0027] Description of the accompanying drawings: 100. Measuring fixtures; 200, positioning pin; 300, go / no-go gauge; 310, go / no-go gauge handle; 320, slide post; 330, go / no-go gauge body; 340, go gauge; 350, no-go gauge; 400, locating pin; 410, locating pin center hole; 420, locating pin handle; 430, locating pin arc; 440, locating pin straight edge; 450, sliding hole; 460, locking hole; 470, co-symmetric axis; 480, intersection; 500, turbine housing body; 600, turbine casing intermediate casing; 610, annular step; 620, reference hole; 630, arc surface. DETAILED DESCRIPTION

[0028] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0029] In the present invention, if directions (up, down, left, right, front and back) are described, it is only for the convenience of describing the technical solution of the present invention, and does not indicate or imply that the technical features referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it cannot be understood as a limitation of the present invention.

[0030] In the present application, the meaning of "several" is one or more, the meaning of "multiple" is two or more, and "greater than", "less than", "more than" and the like are understood as not including the number; "above", "below", "within" and the like are understood as including the number. In the description of the present application, if "first" and "second" are described, they are only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the sequence of indicated technical features.

[0031] In the present application, unless otherwise explicitly limited, the words "set", "mount", "connect" and the like should be broadly understood, for example, they can be directly connected, or indirectly connected through an intermediate medium; can be fixedly connected, or can be detachably connected, or can be integrally formed; can be mechanically connected, or can be electrically connected or capable of communicating with each other; can be the communication or interaction relationship between two elements. The skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0032] A method for measuring the profile of the arc surface 630 on the intermediate shell 600 of the turbine shell according to an embodiment of the present application is described with reference to Figure 3 As shown in the figure, the turbine shell body 500 is provided with a turbine shell intermediate shell 600, and a plurality of arc surfaces 630 protruding radially outward are distributed circumferentially along the center hole of the turbine shell intermediate shell 600. The turbine shell intermediate shell 600 is provided with a plurality of annular steps 610 concentrically arranged with the center hole of the intermediate shell in the direction away from the center hole of the turbine shell body 500; as shown in Figure 1 、 Figure 2 The measuring method comprises the following steps: S1, providing a measuring gauge 100, the measuring gauge 100 comprising a positioning pin 400, a go-no-go gauge 300 and a positioning pin handle 420; The positioning pin 400 is adapted to be positioned on the uppermost annular step 610, and the uppermost annular step 610 is defined as the reference hole 620. The positioning pin 400 comprises a positioning pin center hole 410, and the positioning pin handle 420 is connected to the positioning pin center hole 410. The outer contour of the positioning pin 400 comprises three positioning pin arcs 430 uniformly distributed circumferentially along the positioning pin center hole 410 and coaxial, and a positioning pin straight edge 440 connected between adjacent positioning pin arcs 430; A sliding fit hole 450 is vertically arranged on the surface of the positioning pin 400, the sliding fit hole 450 is close to the positioning pin straight edge 440, and the common symmetry axis 470 of the positioning pin straight edge 440 and the positioning pin arc 430 passes through the diameter of the sliding fit hole 450; The go-no-go gauge 300 comprises a go-no-go gauge handle 310, a slide column 320 and a go-no-go gauge body 330 connected in sequence, the slide column 320 is adapted to slide along the slide fitting hole 450, the go-no-go gauge body 330 comprises a coaxial go gauge 340 and a no gauge 350 in the form of a disc, the no gauge 350 is close to the slide column 320 relative to the go gauge 340, and the go-no-go gauge body 330 partially protrudes from the positioning pin straight edge 440; S2, the operator holds the positioning pin handle 420 with the right hand, adjusts the position of the positioning pin 400 through the positioning pin handle 420, inserts the positioning pin 400 into the reference hole 620, makes the end face of the positioning pin 400 abut on the uppermost annular step 610, and makes the go-no-go gauge body 330 coaxial with the to-be-measured circular arc surface 630, and completes the center positioning; S3, the operator holds the go-no-go gauge handle 310 with the left hand, vertically moves the go-no-go gauge handle 310, moves the go-no-go gauge handle 310 vertically downward along the slide fitting hole 450 to the to-be-measured circular arc surface 630, and judges whether the profile size of the to-be-measured circular arc surface 630 is qualified by observing the passing or stopping of the go gauge 340 and the no gauge 350 on the circular arc surface 630; S4, the positioning pin 400 is taken out and the positioning pin handle 420 is rotated, and the steps S2 to S3 are repeated to complete the measurement of the remaining circular arc surfaces 630.

[0033] By aiming at the structural features of the turbine shell middle shell 600 and combining the actual distribution of the multiple circular arc surfaces 630, the turbine shell parts with complex structure and high measurement requirements can be adapted. Through a set of special measuring tool 100, the profile detection of the multiple-point distributed circular arc surfaces 630 is realized quickly, continuously and systematically, which is beneficial to improve the measurement efficiency and comprehensiveness, and meets the batch production and high consistency detection requirements. The positioning pin 400 can be accurately placed on the annular step 610 (reference hole 620), and is connected through the positioning pin center hole 410 and the handle, which is convenient for operation. The outer contour adopts three concentric circular arcs and straight edge structure, which ensures multiple-point contact with the workpiece, improves the positioning accuracy and measurement stability, and effectively avoids the measurement error caused by positioning deviation. The positioning pin straight edge 440 provides a flat area, so that the go-no-go gauge body 330 is exposed from the positioning pin straight edge 440, which is convenient for coaxial positioning with the to-be-measured circular arc surface 630 through visual observation.

[0034] It should be noted that a portion of the go / no-go gauge body 330 can be exposed from the straight edge 440 of the locating pin through a flat area, allowing the operator to directly observe the relative position of the go / no-go gauge body 330 and the arc surface 630 to be measured. Through visual alignment, the go / no-go gauge body 330 is accurately aligned with the centerline of the arc surface 630 to be measured, achieving coaxial positioning of the go / no-go gauge 300 and the arc surface 630. This structural design not only simplifies the operation steps and prevents the go / no-go gauge 300 from being obscured by the outer contour of the locating pin 400, but also improves the intuitiveness and operational convenience of on-site manual alignment, effectively ensuring the consistency of the axis of the go / no-go gauge 300 and the arc surface 630 during each measurement, thereby improving the accuracy and repeatability of profile measurement.

[0035] In one embodiment, referring to Figures 4 to 6 As shown, taking this drawing as an example, the measuring fixture 100 can measure the diameter of the arc surface 630 and control the contour of the arc surface 630 by changing the diameter (the Y23 dimension in the figure is the converted internal field control dimension).

[0036] Specifically, the outer diameter of the positioning pin 400 is based on the diameter of the reference hole 620 ( 0) of the lower deviation ( 112.98mm) configuration, the outer diameter of the positioning pin 400 ( 1) For Ensure that there is an optimal clearance fit between the locating pin 400 and the reference hole 620 to ensure center positioning accuracy and avoid measurement errors caused by excessive clearance.

[0037] Specifically, the reference hole 620 is used as the center diameter ( 2) For The intersection 480 of the 50.7 mm circle and the common axis of symmetry 470 determines the center of the sliding hole 450. The sliding hole 450 is provided on the surface of the positioning pin 400, and its position strictly corresponds to the axis of symmetry of the positioning pin 400 structure. This helps ensure that the go / no-go gauge 300 slides precisely in the vertical direction, avoiding deflection during measurement and improving measurement accuracy.

[0038] Specifically, the theoretical diameter of the arc surface 630 is 36.00±0.20mm, the dimensions of the go gauge 340 and the stop gauge 350 ( 3 and 4) are mm and mm, can accurately match the arc surface 630 size to achieve high-precision judgment.

[0039] Specifically, a locking hole 460 is arranged radially along the positioning pin straight edge 440 and communicates with the sliding fitting hole 450, the locking hole 460 is used to connect a locking screw, the locking screw can be in abutment with an axially arranged locking groove on the sliding column 320 to limit the sliding of the sliding column 320.

[0040] Specifically, the positioning pin handle 420 and the go-no-go gauge handle 310 are provided with anti-skid knurls. The friction and stability of hand operation are increased, the operation failure is reduced, and the convenience and safety of field measurement are improved.

[0041] Specifically, the circular arc surface 630 is uniformly distributed with five; the positioning pin center hole 410 is a threaded hole, and the positioning pin handle 420 is threadedly connected with the threaded hole.

[0042] Finally, it should be explained that the above specific embodiments are only used to illustrate the technical solutions of the present application and are not limited. Although the present application is described in detail with reference to examples, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the spirit and scope of the technical solutions of the present application, and they should be covered in the scope of the claims of the present application.

Claims

1. A method for measuring the contour of an arc surface (630) on a turbine shell intermediate shell (600), wherein a turbine shell intermediate shell (600) is provided on a turbine shell body (500), a plurality of radially outwardly convex arc surfaces (630) are distributed circumferentially along the center hole of the turbine shell intermediate shell (600), and a plurality of annular steps (610) are distributed on the turbine shell intermediate shell (600) in a direction away from the center hole of the turbine shell body (500) and arranged concentrically with the center hole of the intermediate shell; characterized in that: The measuring method comprises: S1. Providing a measuring fixture (100), wherein the measuring fixture (100) comprises a positioning pin (400), a go / no-go gauge (300), and a positioning pin handle (420); The positioning pin (400) is suitable for being positioned on the uppermost annular step (610), the uppermost annular step (610) is defined as a reference hole (620), the positioning pin (400) includes a positioning pin center hole (410), and the positioning pin handle (420) is connected to the positioning pin center hole (410); The outer contour of the positioning pin (400) includes three positioning pin arcs (430) uniformly distributed along the circumference of the positioning pin center hole (410) and cocircular, and a positioning pin straight edge (440) connected between adjacent positioning pin arcs (430); A sliding hole (450) is vertically provided along the surface of the positioning pin (400), the sliding hole (450) is close to the straight edge (440) of the positioning pin, and a common symmetry axis (470) of the oppositely arranged straight edge (440) of the positioning pin and the circular arc (430) of the positioning pin passes through the diameter of the sliding hole (450); The go / no-go gauge (300) comprises a go / no-go gauge handle (310), a slide post (320) and a go / no-go gauge body (330) connected in sequence, the slide post (320) being adapted to slide along the sliding hole (450), the go / no-go gauge body (330) comprising a coaxially arranged go / no-go gauge (340) and a disc-shaped go / no-go gauge (350), the go / no-go gauge (350) being closer to the slide post (320) relative to the go / no-go gauge (340), and the go / no-go gauge body (330) partially protruding from the straight edge (440) of the positioning pin. S2, adjusting the position of the positioning pin (400) by using the positioning pin handle (420), inserting the positioning pin (400) into the reference hole (620), making the end face of the positioning pin (400) fit on the uppermost annular step (610), and making the go / no-go gauge body (330) and the arc surface to be measured (630) in a coaxial position, thus completing the center positioning; S3, vertically moving the go / no-go gauge handle (310), moving the go / no-go gauge handle (310) vertically downward along the sliding hole (450) to the arc surface (630) to be measured, and judging whether the contour size of the arc surface (630) to be measured is qualified by observing whether the go / no-go gauge (340) and the no-go gauge (350) pass or stop on the arc surface (630); S4. Take out the positioning pin (400) and rotate the positioning pin handle (420), repeat steps S2 to S3, and complete the measurement of the remaining arc surfaces (630).

2. A method for measuring the contour of the upper arc surface (630) of the turbine housing intermediate housing (600) according to claim 1, characterized in that: The outer diameter of the positioning pin (400) is configured according to the lower deviation of the hole diameter of the reference hole (620).

3. A method for measuring the contour of the upper arc surface (630) of the turbine housing intermediate housing (600) according to claim 2, characterized in that: The outer diameter of the positioning pin (400) is mm.

4. A method for measuring the contour of the upper arc surface (630) of the turbine housing intermediate housing (600) according to claim 3, characterized in that: The diameter of the circle with the reference hole (620) as the center is The center position of the sliding hole (450) is determined by the intersection (480) of the 50.7 mm circle and the common symmetry axis (470).

5. A method for measuring the contour of the upper arc surface (630) of the turbine housing intermediate housing (600) according to claim 4, characterized in that: The theoretical diameter of the arc surface (630) is 36.00±0.20mm, the sizes of the go gauge (340) and the stop gauge (350) are respectively mm and mm.

6. A method for measuring the contour of an upper arc surface (630) of a turbine housing intermediate housing (600) according to claim 1, characterized in that: A locking hole (460) is radially arranged along the straight edge (440) of the positioning pin and is connected to the sliding hole (450). The locking hole (460) is used to connect a locking screw. The locking screw can abut against a locking groove axially arranged on the sliding column (320) to limit the sliding of the sliding column (320).

7. A method for measuring the contour of an upper arc surface (630) of a turbine housing intermediate housing (600) according to claim 1, characterized in that: Anti-slip knurling is provided on the positioning pin handle (420) and the go / no-go gauge handle (310).

8. A method for measuring the contour of an upper arc surface (630) of a turbine housing intermediate housing (600) according to claim 1, characterized in that: There are five arc surfaces (630) evenly distributed in the circumferential direction.

9. A method for measuring the contour of an upper arc surface (630) of a turbine housing intermediate housing (600) according to claim 1, characterized in that: The positioning pin center hole (410) is a threaded hole, and the positioning pin handle (420) is threadedly connected to the threaded hole.

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