A measuring device and its usage method for a small plane in a deep cavity

Abstract

This invention discloses a measuring device and its method for use in deep cavity small planes. The device includes a ruler body, a ruler frame, a cover plate, a vernier frame, and a connecting structure. The ruler body is T-shaped, and the ruler frame is Y-shaped with an opening. The ruler body and frame are coaxially arranged, with the ruler body positioned inside the frame. The ruler body and frame are connected, and their ends are connected via the vernier frame. The vernier frame connects the ruler body and frame via the connecting structure. The ruler body and frame respectively contact the end faces of the symmetrical structures to be measured. Reading coordinates are provided on the ruler body. The axis of the measuring device is perpendicular to the plane to be measured. The first contact surface of the measuring device is pressed against the end face of the first symmetrical structure, and the first end face of the measuring device is pressed against the end face of the second symmetrical structure. After the measuring device stabilizes, the reading is taken using the reading coordinates on the ruler body to obtain the measured height difference. This invention solves the problems of previous measurements, significantly shortens the assembly cycle, and improves production efficiency.

Description

Technical Field

[0001] This invention relates to the field of deep cavity height measurement, specifically to a measuring device and method for measuring the height difference of small planes in a deep cavity. Background Technology

[0002] If a depth gauge is used for measurement, even a slight deviation can easily cause a large error. If a vernier caliper is used for measurement, due to the small size of the plane to be measured, the vernier caliper and the part are in contact with a small plane, making it difficult to quickly and accurately position the end faces of the two ring-shaped structural parts. In addition, the measurement environment is located at the bottom of a deep cavity, with narrow space, making it difficult to perform complex manual auxiliary positioning operations, resulting in low measurement efficiency.

[0003] Therefore, the height difference of deep cavity small plane components cannot be measured using traditional devices, but requires the design of other measuring devices based on the component structure.

[0004] How to make reasonable use of the component structure of this type of component to solve the problem of measuring the height difference of the small plane in the deep cavity, so as to carry out rapid and accurate measurement, is particularly important for component assembly.

[0005] like Figure 1 , Figure 3 As shown, specifically in the assembly of a low-pressure turbine unit of a turbofan engine, the front end of the low-pressure turbine shaft is connected to the fan shaft, transmitting torque through a gear sleeve. Axially, it is fixed to the low-pressure rotor by a shoulder and a connecting nut, and positioned by the end face. The low-pressure turbine shaft is bolted to the rotor support cone, and positioned by a stop. At this point, it is necessary to measure the axial height difference ZL between the front end of the low-pressure turbine shaft and the front end of the low-pressure turbine rotor connecting nut. This height difference is caused by the two set annular ends. In this case, the measurement position is located in a deep cavity with a depth of approximately 300 mm and a plane width of approximately 1 mm. It belongs to a small plane in a deep cavity, and the measured height difference is small. In this example, the height difference is 2.5 mm. The wall thickness of both the low-pressure turbine rotor connecting nut and the front end of the low-pressure turbine shaft is 1 mm. The internal cavity depth of the repair unit is approximately 300 mm, and the radius R is 60 mm. If a depth gauge is used to measure the height difference ZL, the depth of the plane to be measured is large (300 mm) in the inner cavity, while the measured height difference is small, and the depth gauge measurement is prone to large errors. If a vernier caliper is used, the wall thickness of the front end of the low-pressure turbine shaft is only 1 mm, which cannot provide a stable and accurate positioning surface. This leads to the problem that the existing reading device will limit the use of the measuring tool and result in large measurement errors.

[0006] Therefore, there is an urgent need for a device to quickly and accurately measure the height difference of small planes in a deep cavity. Summary of the Invention

[0007] To address the difficulties and significant errors in measuring the end-face height difference of symmetrical structures in deep cavity environments in existing technologies, this invention provides a measuring device and method for small planes in deep cavities. The structural design of this measuring device effectively solves the problem of measuring the end-face height difference of double-ring structures in deep cavity environments. This measuring device is convenient and quick to use, solving previous measurement challenges, significantly shortening the assembly cycle, and improving production efficiency.

[0008] This invention is achieved through the following technical solution:

[0009] A measuring device for a small plane in a deep cavity includes a ruler body, a ruler frame, a cover plate, a vernier frame, and a connecting structure. The ruler body is configured as a T-shaped structure, and the ruler frame is configured as a Y-shaped opening structure. The ruler body and the ruler frame are coaxially arranged, with the ruler body disposed within the ruler frame. The ruler body and the ruler frame are connected by a connection, and their ends are connected by a vernier frame. The vernier frame is connected to the ruler body and the ruler frame by the connecting structure. The ruler body and the ruler frame respectively contact the end face of the symmetrical structure to be measured, and the ruler body is provided with reading coordinates.

[0010] Furthermore, the ruler body includes a first end face, and the ruler frame includes a first contact surface, the first contact surface and the first end face being parallel.

[0011] Furthermore, the fit between the ruler body and the ruler frame is achieved through a slide rail on the ruler frame and a fit between the side wall of the ruler body.

[0012] Furthermore, the symmetrical structure to be measured includes a first symmetrical structure and a second symmetrical structure, wherein the first symmetrical structure and the second symmetrical structure are set as concentric circles, the diameter of the first symmetrical structure is smaller than that of the second symmetrical structure, and the height of the first symmetrical structure is greater than that of the second symmetrical structure.

[0013] Furthermore, when the ruler body and the ruler frame are in contact with the end face of the symmetrical structure to be measured, the ruler body is in contact with the end face of the first symmetrical structure to be measured, and the ruler frame is in contact with the end face of the second symmetrical structure to be measured.

[0014] Furthermore, the width of the ruler frame is smaller than the inner edge width of the deep cavity where the structure to be measured is located.

[0015] Furthermore, the cover plate is mounted on the ruler frame via a connecting structure, and the ruler body and ruler frame are connected in sequence.

[0016] Furthermore, the length of the ruler frame and ruler body is longer than the depth of the cavity where the measuring structure is located.

[0017] Furthermore, an adjusting nut is provided on one side of the vernier frame, and the adjusting nut passes through and connects the vernier frame and the scale body.

[0018] A method of using the above-described measuring device for a small plane of a deep cavity, characterized in that the method includes the following steps:

[0019] S1: Align the axis of the measuring device with the plane to be measured;

[0020] S2: Press the first contact surface of the measuring device against the end face of the first symmetrical structure;

[0021] S3: Press the first end face of the measuring device against the end face of the second symmetrical structure;

[0022] S4: After the measuring device reaches stability, take a reading using the reading coordinates set on the ruler to obtain the height difference to be measured.

[0023] Compared with the prior art, the present invention has the following beneficial technical effects:

[0024] This invention provides a measuring device and method for using a small plane in a deep cavity. The structural design of this measuring device effectively solves the problem of measuring the height difference of the end faces of symmetrical structures in a deep cavity environment. The device is convenient and quick to use, solving previous measurement difficulties, significantly shortening the assembly cycle, and improving production efficiency.

[0025] Furthermore, the positioning point of the measuring device of the present invention is that two positioning surfaces are set when the second symmetrical structure is connected, which can ensure the measurement effect in actual use. In the first symmetrical structure, the first end face of the inner ring is positioned by using an integral plane. The structural setting of this part can ensure the measurement effect while also ensuring the stability of the measuring device itself.

[0026] Furthermore, the method of using this measuring device can effectively guarantee the actual measurement results and greatly reduce the occurrence of errors. At the same time, setting the length of the ruler body and the ruler frame to be higher than the depth of the measuring end face can effectively avoid the influence of the narrow space of the deep cavity on the operation. This setting can effectively expand the operating space and ensure the accuracy of the reading. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 The deep cavity environment for measuring the low-vortex rotor connecting nut and the low-pressure turbine shaft;

[0029] Figure 2A schematic diagram showing the positional relationship between the low-pressure turbine shaft and the connecting nut of the low-pressure rotor during measurement.

[0030] Figure 3 A schematic diagram of a device for measuring the height difference of a small plane in a deep cavity, provided in an embodiment of the present invention;

[0031] Figure 4 A schematic diagram of the ruler body of a measuring device for measuring the height difference of a small plane in a deep cavity, provided for an embodiment of the invention;

[0032] Figure 5 A schematic diagram of the frame structure of a measuring device for measuring the height difference of a small plane in a deep cavity, provided for an embodiment of the invention;

[0033] Figure 6 A simplified diagram of the positional structure of a measuring device for measuring the height difference of a small plane in a deep cavity, provided for an embodiment of the invention;

[0034] Figure 7 A simplified structural diagram of the position of the structure under test during measurement using a measuring device for measuring the height difference of a small plane in a deep cavity, provided for an embodiment of the invention;

[0035] Figure 8 A structural diagram illustrating the actual working position of a measuring device for measuring the height difference of a small plane in a deep cavity, provided for an embodiment of the invention.

[0036] In the figure: ruler body 1, ruler frame 2, cover plate 3, vernier frame 4, first screw 5, second screw 6, first end face 11, second end face 12, first contact surface 21, first symmetrical structure 31, second symmetrical structure 32. Detailed Implementation

[0037] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0038] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0039] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0040] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0041] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0042] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0043] Example 1:

[0044] In an embodiment of the present invention, a measuring device is provided for measuring the end face difference of a double-ring structure in a deep cavity environment. In this environment, since the plane to be measured is located deep inside the cavity, and the depth of the deep cavity in this embodiment reaches 300 mm, the internal operating space for actual operation is limited, making measurement difficult. Furthermore, the front wall thickness of the symmetrical low-pressure turbine shaft with measurement is only 1 mm, and when using vernier calipers or depth gauges for measurement, a stable and accurate positioning surface cannot be provided.

[0045] In the measuring device of the present invention, when setting the positioning end face, the number of measuring contact points is increased, increasing the number of contact points during measurement from one point to two points, and maximizing the distance between the two contact points.

[0046] The component to be measured in this case is a double-ring structure. This measuring device can ensure accurate positioning by using the plane positioning of the first end face 11.

[0047] In this case, the vernier frame and its fixing screws can be designed outside the deep cavity.

[0048] The measuring device consists of a ruler body 1, a ruler frame 2, a cover plate 3, a vernier frame 4, and a connecting structure, etc. In this embodiment, the connecting structure uses screws.

[0049] In this embodiment, it is necessary to measure the height difference between the end faces of the low-pressure turbine shaft and the connecting nut of the low-pressure vortex rotor. Loosen the adjusting nut on the vernier frame 4, and position the first contact surface 21 of the ruler frame 2 in contact with the end face to be measured of the low-pressure vortex rotor connecting nut. Then slide the ruler 1 until the first end face 11 of the ruler 1 is in close contact with the two contact points of the end face to be measured of the low-pressure turbine shaft. Then tighten the adjusting nut on the vernier frame, remove the measuring instrument, and read the measurement data according to the vernier caliper reading method. This device has a simple structure, can be easily positioned without manual assistance, and is convenient and quick to use.

[0050] When measuring deep cavities with different structures, the measuring device can be designed using the following steps:

[0051] a. Measure the structural characteristics of the components to be installed and the dimensional features of their mating positions, where ZL is the height difference to be measured;

[0052] b. Design measuring tools based on the structural features and dimensions of components, accessories, and their assembly.

[0053] The component to be measured is a double ring. Since it is an axisymmetric figure, when designing the scale body 1 of the special measuring tool, attention should be paid to ensuring that the first end of the scale body 1 of the special measuring tool is completely placed on the end face to be measured of the first symmetrical structure 31, and should not interfere with the end face to be measured of the second symmetrical structure 32 or other parts of the component.

[0054] The first contact surface of the measuring device frame 2 falls completely on the second symmetrical structure 32 and should not interfere with the first symmetrical structure 31 or other parts of the components. The following dimensional requirements apply: D1 < L1 < L2 < D21 < D22 < L3 < D3.

[0055] The ruler body 1 is configured as a T-shaped structure, the large end of the T-shaped structure is configured as the first end face 11, the small end of the T-shaped structure is configured as the second end face 12, and the small end of the ruler body is configured with reading coordinates;

[0056] The first symmetrical structure 31 and the second symmetrical structure 32 are the workpieces to be measured. In this embodiment, the first symmetrical structure 31 is a low-pressure turbine shaft, and the second symmetrical structure 32 is a low-pressure rotor connecting nut. The diameter of the low-pressure turbine shaft is smaller than that of the low-pressure rotor connecting nut, and the height of the end face to be measured of the low-pressure turbine shaft is higher than that of the low-pressure rotor connecting nut. One end of the ruler frame 2 is set as two ends of a Y-shaped opening, and the end faces of the two ends of the Y-shaped opening are the first contact surfaces.

[0057] Wherein, the outer diameter D1 of the first symmetrical structure is less than the width L1 of the first end of the ruler body; the width L1 of the first end of the ruler body is less than the inner wall distance L2 of the Y-shaped opening end of the ruler frame; the inner wall distance L2 of the two ends of the Y-shaped opening of the ruler frame is less than the inner wall distance D21 of the second symmetrical structure; the inner wall distance D21 of the second symmetrical structure is less than the outer wall distance D22 of the second symmetrical structure; the outer wall distance D22 of the second symmetrical structure is less than the outer wall distance L3 of the two ends of the Y-shaped opening of the ruler frame; the outer wall distance L3 of the two ends of the Y-shaped opening of the ruler frame is less than the radial distance D3 of the inner wall of the measuring deep cavity; at the same time, when the first contact surface 21 and the first end face 11 are on the same horizontal plane, there is a gap between the first contact surface 21 and the first end face 11, and the first contact surface 21 and the first end face 11 are parallel.

[0058] By designing manually operated components of the measuring device outside the deep cavity, the relative position between the scale body 1 and the scale frame 2 can be adjusted by adjusting the adjusting nut in actual use. This effectively avoids the impact of the narrow space of the deep cavity on operation and expands the operating space. In this embodiment, the second screw of the vernier frame 4 is designed outside the deep cavity. The following dimensional requirements apply: h < H, where H is the distance from the first contact surface of the scale body to the origin of the coordinate system on the scale body; h is the depth of the deep cavity to be measured.

[0059] In actual use, loosen the screws on the vernier frame 4, and position the scale frame 2 at the two contact points at the front end of the low-pressure turbine rotor connecting nut. Then slide the scale body 1 until it is in close contact with the two contact points at the front end of the low-pressure turbine shaft. Then tighten the screws on the vernier frame 4, remove the measuring instrument, and read the measurement data according to the reading method of the vernier caliper.

[0060] Table 1 below shows the ZL values ​​measured using vernier calipers and the measuring device proposed in this invention after the first assembly of an engine. Eight sets of data were measured for each, and all measurements were uniformly distributed.

[0061] Table 1. Measurement data of the vernier caliper and the measuring device proposed in this invention.

[0062]

[0063] As can be seen from the table above, due to the difficulty of precise positioning with vernier calipers and operator error, the data measured using vernier calipers are not very consistent, and their average value has a large error compared with the data measured by the measuring device proposed in this invention.

[0064] Table 2 below shows the vernier caliper measurement data after eliminating error values. In this paper, the maximum and minimum values ​​of the vernier caliper measurement data are excluded.

[0065] Table 2. Vernier caliper measurement data after error elimination.

[0066]

[0067] As can be seen from the table above, the standard deviation of the vernier caliper measurement data after eliminating the error value is significantly better than that of the vernier caliper measurement data without eliminating the error value, and its average value is also closer to the average value of the measurement data of the measuring device proposed in this invention. However, there is still a large gap between the measurement results obtained by the measuring device proposed in this invention and the actual measurement results.

[0068] This invention proposes a solution to the problem of measuring the height difference of small planes in deep cavities, and designs a special measuring instrument for this solution. After eight verification tests, it is proven that the measurement method is simple to operate, and the special measuring instrument is convenient to use and has low cost.

[0069] The time for each data measurement has been reduced from half an hour or even longer to no more than 5 minutes, which greatly saves measurement time and effectively solves the problem of measuring the height difference of small planes in deep cavities, thus greatly improving assembly efficiency.

[0070] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0071] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A measuring device for a deep cavity facet, characterized in that, The utility model relates to a kind of measurement devices, including ruler body (1), ruler frame (2), cover plate (3), vernier frame (4) and connecting structure, the ruler body (1) is set to T type structure, the ruler frame (2) is set to Y type opening structure, the ruler body (1) and ruler frame (2) coaxial arrangement, the ruler body (1) is arranged in ruler frame (2), the ruler body (1) and ruler frame (2) are connected by cover plate (3), the ruler body (1) and ruler frame (2) are connected by vernier frame (4), the vernier frame (4) is connected ruler body (1) and ruler frame (2) by connecting structure, the ruler body (1) and ruler frame (2) are respectively and the end surface of the symmetrical structure to be measured contact, reading coordinate is set on the ruler body (1); The symmetrical structure to be measured includes first symmetrical structure (31) and second symmetrical structure (32), the first symmetrical structure (31) and second symmetrical structure (32) are set as concentric circles, the first symmetrical structure (31) diameter is less than second symmetrical structure (32), the first symmetrical structure (31) height is greater than second symmetrical structure (32); When the ruler body (1) and ruler frame (2) are respectively and the end surface of the symmetrical structure to be measured contact, the ruler body (1) and the end surface of the first symmetrical structure (31) to be measured contact, the ruler frame (2) and the end surface of the second symmetrical structure (32) to be measured contact.

2. The apparatus for measuring a deep-cavity facet according to claim 1, wherein The ruler body (1) includes first end surface (11), and the ruler frame (2) includes first contact surface (21), and the first contact surface (21) is parallel to the first end surface (11).

3. The apparatus for measuring a deep-cavity facet according to claim 1, wherein The cooperation connection between the ruler body (1) and the ruler frame (2) is connected by the cooperation of the slide rail on the ruler frame (2) and the side wall of the ruler body (1).

4. The apparatus for measuring a deep-cavity facet according to claim 1, wherein The width of the ruler frame (2) is less than the inner edge width of the deep cavity where the structure to be measured is located.

5. The apparatus for measuring a deep-cavity facet according to claim 1, wherein The cover plate (3) is arranged on the ruler frame (2) by the connecting structure, and the cover plate (3), the ruler body (1) and the ruler frame (2) are sequentially connected.

6. The apparatus for measuring a deep-cavity facet according to claim 1, wherein The length of the ruler frame (2) and the ruler body (1) is longer than the depth of the deep cavity where the structure to be measured is located.

7. The apparatus for measuring a deep-cavity facet according to claim 1, wherein One side of the vernier frame (4) is provided with an adjusting nut, and the adjusting nut penetrates the vernier frame (4) and the ruler body (1).

8. A method of using a measuring device for a deep-cavity facet according to any one of the preceding claims 1 to 7, characterized in that, The use method comprises the following steps: S1: the axis of the measuring device is perpendicular to the plane to be measured; S2: the first contact surface (21) of the measuring device is pressed against the end surface of the first symmetrical structure (31); S3: the first end surface (11) of the measuring device is pressed against the end surface of the second symmetrical structure (32); S4: after the measuring device reaches stability, reading is performed through the reading coordinate provided on the ruler body (1), and the height difference to be measured is obtained.

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