Fixture for measuring the flatness of castings

Abstract

This invention discloses a casting flatness measuring fixture, comprising a circular base, a support seat mounted on the base, a pin vertically mounted on the base, a measuring rod slidably connected to the pin and capable of rotating around the pin, and an indicator for measuring flatness mounted on the measuring rod. The measuring rod has a first linear groove for passing through the pin, the width of which is adapted to the diameter of the pin. This casting flatness measuring fixture is simple in structure, easy to use, and can quickly, intuitively, and accurately complete flatness measurements. It ensures that only casting blanks with acceptable flatness dimensions can proceed to subsequent production, avoiding the problem of measuring only after all product processing is completed, where problems discovered later cannot be remedied, severely impacting production progress.

Description

Technical Field

[0001] This invention relates to the field of aero-engine technology, and in particular, to a measuring fixture for the flatness of castings. Background Technology

[0002] Aircraft engines are typically precision castings produced using the lost-wax casting method. The surface of the casting blank usually does not require overall machining; only local high points on the surface are machined to ensure that the dimensions of the casting blank, especially the flatness, meet the standards before assembly and use.

[0003] Existing flatness measuring devices consist of a measuring dial indicator mounted on a linear base, capable of translating along the length of the base. For example, Chinese patent CN212963166U describes a method where the linear base is placed on a horizontal platform, the workpiece to be measured is placed in the gap between the base and the platform, and the flatness of the workpiece is measured using the dial indicator. However, due to the diverse shapes of aero-engine castings, existing flatness measuring devices suffer from the following problems in use:

[0004] 1. Some casting blanks have various protruding structures on the plane to be measured, which limits the measurement space of the casting blank. Moreover, the areas to be measured are not on the same straight line. During measurement, it is necessary to frequently adjust the relative position of the flatness measuring device and the casting blank. Whether adjusting the position of the flatness measuring device or adjusting the relative position of the casting blank, it is inconvenient to operate and prone to errors, affecting the measurement accuracy.

[0005] 2. Due to structural characteristics, some casting blanks have uneven bottoms or residual risers, resulting in an angle of less than 15° between the plane to be measured and the horizontal plane after placement. This renders the originally agreed-upon datum plane unusable. Furthermore, the protruding structures on the plane to be measured prevent the straight base from being placed directly, making the process of reselecting a datum plane cumbersome. If all the product processing is completed before measurement, it is difficult to guarantee that the dimensions of the product blank surface, especially the flatness dimension, will meet the standards during production. Problems discovered later cannot be remedied, seriously affecting the production schedule.

[0006] Therefore, there is an urgent need to develop a new measuring fixture to solve the problem of measuring the flatness of products in the casting blank stage. Summary of the Invention

[0007] This invention provides a fixture for measuring the flatness of castings, which solves the technical problem that existing flatness measuring devices are not suitable for castings with raised structures on the plane to be measured, or castings with uneven bottoms or residual risers at the bottom. When the originally agreed reference surface cannot be used, the operation of measuring flatness is inconvenient and prone to errors.

[0008] According to one aspect of the present invention, a measuring fixture for measuring the flatness of a casting is provided, comprising a circular base, a support seat disposed on the base, a pin disposed vertically on the base, a measuring rod slidably connected to the pin and rotatable about the pin, and an indicator for measuring flatness disposed on the measuring rod, wherein the measuring rod has a first linear groove for passing through the pin, the width of the first linear groove being adapted to the diameter of the pin.

[0009] Furthermore, the chassis has multiple sets of arc-shaped sliding grooves arranged concentrically with the chassis, and the support base is slidably connected to the arc-shaped sliding grooves.

[0010] Furthermore, each set of the arc-shaped slide grooves has at least two, and each arc-shaped slide groove is provided with a first locking member for locking the support base. The first locking member passes through the corresponding arc-shaped slide groove and is directly connected to the support base.

[0011] Furthermore, the support base is provided with a second straight slide groove arranged in the radial direction of the chassis, and the first locking member is provided with a locking nut. The first locking member passes through the arc-shaped slide groove and the second straight slide groove, and the position of the support base is fixed by the locking nut.

[0012] Furthermore, the bottom surface of the support base is provided with height-adjustable support pins.

[0013] Furthermore, the support pin is provided with scale lines for indicating the support height.

[0014] Furthermore, the indicator includes a meter head for displaying numerical values, a fixing rod for connecting the measuring rod, and a measuring head for measuring flatness. The measuring rod has a clamping hole passing through the fixing rod and a second locking member for locking the fixing rod.

[0015] Furthermore, the measuring head is equipped with a bent head to avoid interference with protruding structures on the plane to be measured.

[0016] Furthermore, a first weight-reduction window is provided on the measuring rod.

[0017] Furthermore, a second weight-reduction window is provided on the chassis.

[0018] The present invention has the following beneficial effects:

[0019] The casting flatness measuring fixture of this invention involves placing the support base in the gap of the protruding structure on the plane to be measured, making the base parallel to the plane and thus changing the reference plane. Even if the plane to be measured is tilted from the horizontal plane when the casting blank is placed, making the originally agreed reference plane unusable, the measurement reference plane can be quickly re-established, ensuring smooth flatness measurement. After the support base is in place, the measuring rod is held to move or rotate the indicator. During the measurement process, the bottom surface of the measuring rod is kept in contact with the top surface of the base to achieve reference plane conversion and ensure measurement accuracy. The flatness of multiple different areas can be measured without moving the support base, thus realizing the flatness measurement of the workpiece in the circumferential and radial directions. The change in the indicator reading determines whether the flatness of the casting blank meets the standard. The structure is simple, easy to use, and can quickly, intuitively, and accurately complete the flatness measurement. Only casting blanks with flatness dimensions that meet the standard can proceed to subsequent production. This avoids the problem of measuring after all the processing of the product is completed, where problems are discovered later and cannot be remedied, seriously affecting the production schedule.

[0020] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0021] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0022] Figure 1 This is a schematic diagram of the structure of a casting flatness measuring fixture according to a preferred embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the measuring rod according to a preferred embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of the structure of the indicator table according to a preferred embodiment of the present invention;

[0025] Figure 4 This is a schematic diagram of the chassis structure according to a preferred embodiment of the present invention;

[0026] Figure 5 This is a schematic diagram of the arc-shaped groove according to a preferred embodiment of the present invention.

[0027] Legend:

[0028] 100. Workpiece to be measured; 1. Chassis; 11. Arc-shaped slide groove; 111. Boss; 12. First locking element; 13. Second weight-reducing window; 14. Locking nut; 15. Handle; 2. Support base; 21. Support pin; 22. Second linear slide groove; 24. Scale line; 3. Pin shaft; 31. Pin cap; 4. Measuring rod; 41. First linear slide groove; 42. Clamping hole; 43. Second locking element; 44. First weight-reducing window; 5. Indicator; 51. Indicator head; 52. Fixing rod; 53. Measuring head; 54. Bending head. Detailed Implementation

[0029] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0030] like Figure 1 and Figure 2 As shown, the casting flatness measuring fixture of this embodiment includes a circular base 1, a support seat 2 arranged on the base 1, a pin 3 vertically arranged on the base 1, a measuring rod 4 slidably connected to the pin 3 and rotatable about the pin 3, and an indicator 5 for measuring flatness arranged on the measuring rod 4. The measuring rod 4 has a first linear groove 41 for passing through the pin 3, and the width of the first linear groove 41 is adapted to the diameter of the pin 3.

[0031] In use, the support base 2 is placed in the gap of the protruding structure on the plane to be measured of the workpiece 100, so that the base 1 is parallel to the plane to be measured, thereby changing the reference plane. Even if the plane to be measured is tilted from the horizontal plane when the casting blank is placed, making the originally agreed reference plane unusable, the measurement reference plane can be quickly re-determined, ensuring that the flatness measurement is carried out smoothly. After the support base 2 is placed, the measuring rod 4 is held to drive the indicator 5 to move or rotate. During the measurement process, the bottom surface of the measuring rod 4 is kept in contact with the top surface of the base 1 to realize the conversion of the reference plane and ensure measurement accuracy. The flatness of multiple different areas can be measured without moving the support base 2, thereby realizing the flatness measurement of the workpiece 100 in the circumferential and radial directions. The flatness of the casting blank is judged by the change of the reading of the indicator 5. The structure is simple and easy to use. It can quickly, intuitively and accurately complete the flatness measurement, ensuring that the casting blank with the flatness dimension meets the standard before subsequent production. It can avoid the problem of measuring after all the processing of the product is completed, and the problem of being unable to remedy the problem later, which seriously affects the production schedule. Optionally, the height of the pin 3 is greater than the thickness of the measuring rod 4, which can raise the measuring rod 4 so that the indicator 5 can pass over the protrusion on the plane to be measured. Optionally, the pin 3 is provided with a pin cap 31 to prevent the measuring rod 4 from falling out. Optionally, the two sets of measuring rods 4 are arranged at an angle. On the one hand, the two sets of measuring rods 4 can be connected in a "Y" shape, with the forked ends forming crossbars at a preset angle, which can obtain a set of flatness data according to the preset angle, thus improving the measurement efficiency. On the other hand, the two sets of measuring rods 4 can be stacked and fitted on the pin 3, which can simultaneously measure the flatness at different radial positions, facilitating real-time observation and comparison of data.

[0032] like Figure 3 and Figure 4 As shown in this embodiment, the chassis 1 has multiple sets of arc-shaped sliding grooves 11 arranged concentrically with the chassis 1. The support seat 2 is slidably connected to the arc-shaped sliding grooves 11. In use, the position of the support seat 2 can be adjusted according to the gap of the protrusion on the casting blank to facilitate the determination of the reference surface.

[0033] Optionally, a first locking member 12 for locking the support base 2 is provided inside the arc-shaped slide groove 11, which can slide along the arc-shaped slide groove 11. Optionally, the first locking member 12 is threadedly connected to the threaded hole. Optionally, a boss 111 is provided inside the arc-shaped slide groove 11. One end of the locking member 12 engages with the boss 111, and the other end passes through the arc-shaped slide groove 11 and is threadedly connected to the top surface of the support base 2. The height of the arc-shaped slide groove 11 is greater than the sum of the heights of the boss 111 and the engagement member, so that the engagement member is completely embedded in the arc-shaped slide groove 11, preventing the engagement member from blocking the rotation of the measuring rod 4.

[0034] Optionally, each set of arc-shaped slide grooves 11 is one, and a slider that can slide along the arc-shaped slide groove 11 is embedded in the arc-shaped slide groove 11. The slider is fixedly connected to the top surface of the support base 2. The two side walls of the slider that fit against the arc-shaped slide groove 11 are arc-shaped to prevent the support base 2 from rotating. A threaded hole is opened on the top surface of the slider.

[0035] like Figure 2 and Figure 3 As shown, in this embodiment, each set of arc-shaped slide grooves 11 consists of two parts. Each arc-shaped slide groove 11 is provided with a first locking member 12 for locking the support base 2. The first locking member 12 passes through the corresponding arc-shaped slide groove 11 and is directly connected to the support base 2. By fixing the support base 2 with two first locking members 12, the rotation of the support base 2 can be prevented, ensuring that the support point of the chassis 1 will not move during measurement, thereby ensuring measurement accuracy. Optionally, the first locking member 12 is a screw.

[0036] like Figure 4 As shown in this embodiment, the support base 2 is provided with a second straight slide groove 22 arranged in the radial direction of the chassis 1, and a locking nut 14 is provided on the first locking member 12. The first locking member 12 passes through the arc-shaped slide groove 11 and the second straight slide groove 22, and the position of the support base 2 is fixed by the locking nut 14. In use, loosening the locking nut 14 can adjust the position of the support base 2 in the circumferential direction of the chassis 1 and the position of the support base 2 in the radial direction of the chassis 1. The position of the support base 2 can be adjusted according to the structural characteristics of the casting blank, thereby quickly determining the reference surface.

[0037] like Figure 2 and Figure 5 As shown in this embodiment, adjustable support pins 21 are arranged on the bottom surface of the support base 2. The height of the support pins 21 can be adjusted according to the requirements. For casting blanks with protrusions or depressions on the plane to be measured, the height of each support pin 21 can be adjusted separately. By placing multiple support pins 21 of different heights at different height positions, the reference surface can be redefined. This method is applicable to the flatness measurement of various irregular castings.

[0038] like Figure 2 and Figure 5 As shown, in this embodiment, the support pin 21 is provided with scale lines 24 for indicating the support height, so as to facilitate the adjustment of the height of the support pin 21 and quickly determine the reference surface.

[0039] like Figure 2 , Figure 3 and Figure 4As shown, in this embodiment, the indicator 5 includes a meter head 51 for displaying numerical values, a fixing rod 52 for connecting the measuring rod 4, and a measuring head 53 for measuring flatness. The measuring rod 4 has a clamping hole 42 passing through the fixing rod 52 and a second locking member 43 for locking the fixing rod 52. The measuring head 53 of the indicator 5 moves up and down during movement, causing the reading of the meter head 51 to change, thus quickly, intuitively, and accurately completing the flatness measurement. In use, loosening the second locking member 43 allows for the replacement of the indicator 5 or adjustment of the height of the measuring head 53. The structure is simple and the operation is convenient. Optionally, the second locking member 43 is a locking screw. Rotating the locking screw causes it to abut against the outer wall of the fixing rod 52, thereby locking the fixing rod 52. Rotating the locking screw in the opposite direction moves it away from the fixing rod 52, allowing for adjustment of the height of the fixing rod 52 or replacement of the entire indicator 5. Optionally, a slot is provided on the measuring rod 4, with one end of the slot communicating with the clamping hole 42 and the other end communicating with the side wall of the measuring rod 4, forming a clamping block at one end of the measuring rod 4. A locking screw passes through the clamping block and is threadedly connected to the measuring rod 4. The width of the slot is adjusted by rotating the locking screw, thereby locking / loosening the fixing rod 52. Optionally, the meter 51 is an analog or digital display type.

[0040] like Figure 3 As shown, in this embodiment, the measuring head 53 is equipped with a bending head 54 to avoid interference with protruding structures on the surface to be measured. For casting blanks with multiple protrusions on the surface to be measured, a conventional measuring head 53 cannot reach the irregular gaps, or the protrusions may block the measuring head 53, preventing it from reaching the measurement point. In cases where surface flatness must be measured, the bending head 54 is used to ensure the flatness dimensions of the blank meet the standard. This avoids measuring after all product processing is completed, which could lead to irreparable problems later. Optionally, the bending head 54 is Z-shaped. Optionally, the measuring head 53 and the bending head 54 can be detachably connected or welded together.

[0041] like Figure 2 , Figure 3 and Figure 5 As shown, in this embodiment, the measuring rod 4 is provided with a first weight-reducing window 44, which can reduce the weight of the entire device without affecting the strength of the measuring rod 4, thereby reducing the burden during use. Optionally, the first weight-reducing window 44 has the same shape as the first linear slide 41. In use, the pin cap 31 is removed, and the pin shaft 3 is inserted into the first linear slide 41 or the first weight-reducing window 44 to adjust the measuring radius of the indicator 5, which can be applied to the measurement of castings of different sizes.

[0042] like Figure 4As shown, in this embodiment, a second weight-reducing window 13 is provided on the chassis 1, which can reduce the weight of the entire device without affecting the strength of the chassis 1, thereby reducing the burden during use. Optionally, the second weight-reducing window 13 is fan-shaped, and a handle 15 is formed between two adjacent second weight-reducing windows 13 to facilitate handling, adjustment and measurement.

[0043] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A measuring fixture for the flatness of a casting, characterized in that it comprises a circular base plate (1), a support seat (2) arranged on the base plate (1), a pin shaft (3) arranged vertically on the base plate (1), a measuring rod (4) in sliding connection with the pin shaft (3) and rotatable about the pin shaft (3), and an indicating table (5) for measuring the flatness arranged on the measuring rod (4).

2. The measuring fixture for the flatness of a casting according to claim 1, characterized in that each group of the arc-shaped sliding grooves (11) is at least two, and each arc-shaped sliding groove (11) is arranged with a first locking member (12) for locking the support seat (2), and the first locking member (12) is directly connected with the support seat (2) through the corresponding arc-shaped sliding groove (11).

3. The measuring fixture for the flatness of a casting according to claim 2, characterized in that the support seat (2) is arranged with a second linear sliding groove (22) along the radial direction of the base plate (1), the first locking member (12) is arranged with a locking nut (14), and the first locking member (12) passes through the arc-shaped sliding groove (11) and the second linear sliding groove (22) to fix the position of the support seat (2) through the locking nut (14).

4. The measuring fixture for the flatness of a casting according to claim 1, characterized in that the bottom surface of the support seat (2) is arranged with a height-adjustable support pin (21).

5. The measuring fixture for the flatness of a casting according to claim 4, characterized in that the support pin (21) is arranged with a scale line for indicating the support height.

6. The measuring fixture for the flatness of a casting according to claim 1, characterized in that the indicating table (5) comprises a table head (51) for displaying numerical values, a fixed rod (52) for connecting the measuring rod (4), and a measuring head (53) for measuring the flatness, and the measuring rod (4) is arranged with a clamping hole (42) passing through the fixed rod (52) and a second locking member (43) for locking the fixed rod (52).

7. The measuring fixture for the flatness of a casting according to claim 6, characterized in that the measuring head (53) is arranged with a bent head (54) for avoiding interference with the protruding structure on the plane to be measured.

8. The measuring fixture for the flatness of a casting according to claim 1, characterized in that ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ A first lightening window (44) is formed in the measuring rod (4).

9. The cast flatness measuring fixture of claim 1 wherein, A second lightening window (13) is formed in the base plate (1).

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