Device for measuring the distance between the bottom of a counterbore and the lowest point of a circular arc

Abstract

This utility model relates to the field of measuring tool technology, specifically to a device for measuring the distance between the bottom surface of a countersunk hole and the lowest point of a circular arc. It includes a reference plate, a distance gauge, a positioning shaft, a measuring column, a positioning seat, and a base plate. The positioning shaft is fixed to the base plate and engages with the countersunk hole of the part, ensuring close contact between the bottom surface of the countersunk hole and the upper surface of the positioning shaft. The reference plate is fixed to the base plate, with its reference surface A and the reference surface E of the positioning shaft on the same plane. The positioning seat is fixed to the base plate, with one side abutting against the side of the part. The measuring column is positioned within the circular arc surface of the part. The distance gauge includes a gauge body and two extensions extending from the top of the gauge body: a go gauge end and a no-go gauge end. The bottom of the gauge body slides in contact with the reference surface A of the reference plate. This device ensures the accuracy of measuring the distance between the bottom surface of the countersunk hole and the lowest point of the circular arc during actual production, while effectively improving measurement efficiency.

Description

Technical Field

[0001] This utility model relates to the field of measuring tool technology, specifically to a device for measuring the distance between the bottom surface of a countersunk hole and the lowest point of a circular arc. Background Technology

[0002] In the case of Figure 1 In the manufacturing process of this special mechanical part, the precision requirements for the distance H0 between the bottom surface of the countersunk hole and the lowest point of the arc are extremely stringent. However, the arc surface of the part exhibits the characteristics of a spatial line, and its unique geometric position is very difficult to identify, posing numerous challenges to accurate measurement.

[0003] In current production practices, general-purpose instruments such as coordinate measuring machines (CMMs) are frequently used for inspection. However, despite being a high-precision, general-purpose measurement method, CMMs still have the following significant drawbacks when applied to this specific scenario:

[0004] I. Poor environmental adaptability

[0005] In actual production environments, issues such as vibration, dust pollution, and limited working space often exist, which are completely incompatible with the precise, stable, and clean environment required by a coordinate measuring machine (CMM) room. For example, continuous vibration on-site may interfere with the coordinate acquisition accuracy of the measuring equipment, causing fluctuations in measurement data; for example, since dust easily adheres to the measuring probe and the surface of parts, the accuracy of this contact measurement will be difficult to guarantee, and may even cause the probe to jam or be damaged due to dust accumulation; for example, when the working space is limited, it often restricts the normal setup and operation of the measuring equipment, which greatly increases the difficulty of implementing on-site measurements, easily leading to increased measurement errors, and in severe cases, even making effective measurements impossible.

[0006] II. Low efficiency in feature recognition and measurement

[0007] For the unique linear feature of the lowest point of a circular arc surface, coordinate measuring machine (CMM) measurement requires point cloud acquisition and feature fitting. However, because this linear feature is extremely subtle and unique in space, high-density, high-precision scanning is necessary to cover this feature area during point cloud acquisition, significantly increasing the amount of data collected. Furthermore, in the subsequent feature fitting process, accurately extracting the linear feature representing the lowest point of the arc from massive point cloud data requires complex algorithm calculations and measurement path planning. This not only demands extremely high levels of expertise from operators but also results in lengthy data processing times and extremely low measurement efficiency, making it impossible to meet the needs of rapid detection and timely feedback of quality information on the production site.

[0008] Third, conventional measuring tools such as calipers and micrometers, due to the limitations of their measurement principles (based on contact-type two-point or plane measurement), have difficulty in stably and accurately positioning their measuring contacts on the feature line when they come into contact with it. Therefore, they cannot effectively capture the line feature of the lowest point of the arc surface. At the same time, the space inside the countersunk hole area of ​​the part is narrow, and the structure of conventional measuring tools cannot penetrate into it, making it impossible to establish an effective measurement connection with the datum plane G at the bottom of the countersunk hole. As a result, it is impossible to accurately measure H0, and its practicality in this specific measurement scenario is almost zero.

[0009] Therefore, how to quickly and accurately measure the distance H0 between the bottom surface of the countersunk hole and the lowest point of the arc in actual production to meet production requirements has always been a problem that needs to be solved by those skilled in the art. Summary of the Invention

[0010] The purpose of this invention is to address the shortcomings of existing technologies by providing a device for measuring the distance between the bottom surface of a countersunk hole and the lowest point of a circular arc. This device can ensure the accuracy of measuring the distance between the bottom surface of the countersunk hole and the lowest point of the circular arc in actual production, while effectively improving the measurement efficiency.

[0011] The objective of this utility model is achieved through the following solution:

[0012] A device for measuring the distance between the bottom surface of a countersunk hole and the lowest point of a circular arc includes a reference plate, a distance gauge, a positioning shaft, a measuring column, a positioning seat, and a base plate, wherein:

[0013] The positioning shaft is fixed on the base plate and engages with the countersunk hole of the part, so that the bottom surface of the countersunk hole is in close contact with the upper surface of the positioning shaft. The reference plate is fixed on the base plate so that the reference surface A of the reference plate and the reference surface E of the positioning shaft are on the same plane.

[0014] The positioning seat is fixed on the base plate, and one side of the positioning seat abuts against the side of the part. The measuring column is set in the arc surface of the part. The distance gauge includes a gauge body and a go gauge end and a no-go gauge end extending from the top of the gauge body to both ends. The bottom of the gauge body slides in contact with the reference surface A of the reference plate. During measurement, by observing whether the go gauge end and the no-go gauge end can pass through the top of the measuring column, it is determined whether the distance between the bottom surface of the countersunk hole of the part and the lowest point of the arc surface meets the requirements.

[0015] Preferably, the measuring column includes a measuring column body and extensions disposed at both ends of the measuring column body, and the surface of the extensions is provided with a mesh structure;

[0016] The diameter of the extension is smaller than the diameter of the measuring column body, and the diameter of the measuring column body is smaller than the diameter of the arc surface of the part.

[0017] Preferably, the bottom surface of the go gauge end is reference surface C, the bottom surface of the no-go gauge end is reference surface D, and the bottom of the gauge body is reference surface B, wherein the distance between reference surface C and reference surface B is greater than the distance between reference surface D and reference surface B.

[0018] The distance between the reference surface C and the reference surface B is the sum of the maximum value of the distance from the bottom surface of the countersunk hole of the part to the lowest point of the arc and the diameter of the measuring column body.

[0019] The distance between the reference surface D and the reference surface B is the sum of the minimum distance from the bottom surface of the countersunk hole of the part to the lowest point of the arc and the diameter of the measuring column body.

[0020] Preferably, it also includes a dial indicator for detecting the actual distance between the bottom surface of the countersunk hole and the lowest point of the arc of the part.

[0021] Preferably, the base plate is provided with multiple threaded holes and pin holes for fixing the base plate to the reference plate and the base plate to the positioning seat.

[0022] Preferably, the base plate has a positioning hole in the middle for fixing the positioning shaft, the positioning shaft includes a mounting part, and the mounting part and the positioning hole are interference fit.

[0023] Preferably, the positioning shaft further includes a positioning part, the diameter of which is larger than the diameter of the mounting part, and the height of which is greater than the depth of the countersunk hole of the part.

[0024] Preferably, the plane on which the positioning seat abuts against the part is a reference surface F, and the reference surface F is perpendicular to the reference surface A of the reference plate and the reference surface E of the positioning shaft, and the perpendicularity error does not exceed 0.01mm.

[0025] Preferably, the dimension of the reference plate along the length of the base plate is larger than the dimension of the gauge body along the length of the base plate.

[0026] Preferably, the distance L4 between the central axis of the positioning shaft and the reference surface F of the positioning seat is less than the distance L1 between the central axis of the countersunk hole of the part and the side wall H of the part away from the arc surface.

[0027] The beneficial effects of this utility model are as follows:

[0028] A device for measuring the distance between the bottom surface of a countersunk hole and the lowest point of a circular arc includes a reference plate, a distance gauge, a positioning shaft, a measuring column, a positioning seat, and a base plate, wherein:

[0029] The positioning shaft is fixed on the base plate and engages with the countersunk hole of the part, so that the bottom surface of the countersunk hole is in close contact with the upper surface of the positioning shaft. The reference plate is fixed on the base plate so that the reference surface A of the reference plate and the reference surface E of the positioning shaft are on the same plane.

[0030] The positioning seat is fixed to the base plate, with one side abutting against the side of the part. The measuring column is set within the arc surface of the part. The distance gauge includes a gauge body and two ends extending from the top of the gauge body: a go gauge end and a no-go gauge end. The bottom of the gauge body slides in contact with the reference surface A of the reference plate. During measurement, by observing whether the go gauge end and the no-go gauge end can pass over the measuring column, it is determined whether the distance between the bottom surface of the countersunk hole and the lowest point of the arc of the part meets the requirements. By setting up the above device, the distance between the bottom surface of the countersunk hole and the lowest point of the arc of the part can be accurately and quickly measured during the production process.

[0031] Preferably, the measuring column includes a measuring column body and extensions disposed at both ends of the measuring column body. The surface of the extensions is provided with a textured structure to enhance friction and facilitate operation.

[0032] The diameter of the extension is smaller than the diameter of the measuring column body, and the diameter of the measuring column body is smaller than the diameter of the arc surface of the part, so that the measuring column can be at the lowest position of the arc surface during measurement, thereby improving the accuracy of the measurement.

[0033] Preferably, the bottom surface of the go gauge end is reference surface C, the bottom surface of the no-go gauge end is reference surface D, and the bottom of the gauge body is reference surface B, wherein the distance between reference surface C and reference surface B is greater than the distance between reference surface D and reference surface B.

[0034] The distance between the reference surface C and the reference surface B is the sum of the maximum value of the distance from the bottom surface of the countersunk hole of the part to the lowest point of the arc and the diameter of the measuring column body.

[0035] The distance between the reference surface D and the reference surface B is the sum of the minimum distance from the bottom surface of the countersunk hole of the part to the lowest point of the arc and the diameter of the measuring column body.

[0036] This invention, by setting up go and no-go gauge ends at different heights, allows the go gauge end (reference surface C) of the distance gauge 2 to directly determine whether the distance H0 from the bottom surface of the countersunk hole to the lowest point of the arc exceeds the maximum allowable value, while the no-go gauge end (reference surface D) can directly determine whether the distance H0 from the bottom surface of the countersunk hole to the lowest point of the arc is lower than the minimum allowable value. Through the simple operation of "go gauge can pass, no-go gauge cannot pass," it is possible to quickly determine whether H0 is within the acceptable range without complex calculations. In other words, this universal principle of "go gauge controlling the maximum material boundary, no-go gauge controlling the minimum material boundary" allows for measurement on the production floor without relying on precision instruments such as coordinate measuring machines, solely through the movement and passability judgment of the distance gauge. This significantly improves inspection efficiency and effectively adapts to the rapid quality inspection needs of mass production.

[0037] Preferably, it also includes a dial indicator for detecting the actual distance between the bottom surface of the countersunk hole and the lowest point of the arc of the part, so as to obtain the actual difference of the part and adjust the feed rate according to the actual difference, which can effectively improve the pass rate of part machining.

[0038] Preferably, the base plate is provided with multiple threaded holes and pin holes for fixing the base plate to the reference plate and the base plate to the positioning seat.

[0039] The base plate of this utility model is fixedly connected to the reference plate and the positioning seat through threaded holes and pin holes. On the one hand, it can ensure the positioning accuracy of the reference plate and the positioning seat and ensure the consistency of the measurement reference. On the other hand, it can avoid the loosening or displacement of the parts due to external forces during measurement operations (such as pushing parts or moving distance gauges), thereby ensuring the reliability of the measurement results.

[0040] Preferably, the base plate has a positioning hole in the middle for fixing the positioning shaft. The positioning shaft includes a mounting part, and the mounting part and the positioning hole are interference fit, which can effectively ensure the positional accuracy and stability of the positioning shaft.

[0041] Preferably, the positioning shaft further includes a positioning part, the diameter of which is larger than the diameter of the mounting part, so as to ensure the positioning accuracy of the part and reduce measurement errors. The height of the positioning part is greater than the depth of the countersunk hole of the part, so that when the countersunk hole of the part is fitted into the positioning part, the bottom surface of the countersunk hole can be in complete and tight contact with the upper surface (reference surface E) of the positioning part, avoiding the problem of "incomplete fit" caused by insufficient height of the positioning part, ensuring that the positioning reference of the part in the axial direction is stable and reliable, and providing an accurate axial reference for subsequent measurement of the gauge column placed at the lowest point of the arc surface and the distance gauge 2.

[0042] Preferably, the reference surface F of the positioning seat abutting the part is perpendicular to the reference surface A of the reference plate and the reference surface E of the positioning shaft, and the perpendicularity error does not exceed 0.01mm. This ensures accurate positioning of the part during measurement, avoids tilting or positional shift of the part due to non-perpendicularity of the reference surfaces, effectively avoids measurement misjudgment caused by positioning errors, and improves the accuracy and reliability of the measurement.

[0043] Preferably, the dimension of the reference plate along the length of the base plate is larger than the dimension of the gauge body along the length of the base plate.

[0044] The dimension of the reference plate along the length of the base plate of this utility model is larger than the dimension of the gauge body along the length of the base plate. This can effectively ensure that when the distance gauge moves to the right along the reference plate for measurement, there is always a sufficiently long reference surface for it to fit. This avoids the distance gauge from falling off the reference surface during the movement due to the reference plate being too short. This ensures the stability of the reference during distance gauge measurement and guarantees the accuracy of the measured value of the distance H0 from the bottom surface of the countersunk hole of the part to the lowest point of the arc surface.

[0045] Preferably, the distance L4 between the central axis of the positioning shaft and the reference surface F of the positioning seat is less than the distance L1 between the central axis of the countersunk hole of the part and the side wall H of the part away from the arc surface.

[0046] In this invention, the distance L4 between the central axis of the positioning shaft and the reference surface F of the positioning seat is smaller than the distance L1 between the central axis of the countersunk hole of the part and the side wall H of the part away from the arc surface. This ensures that when the part is measured, a slight clamping force is generated when the part contacts the reference surface F of the positioning seat, forcing the bottom surface of the countersunk hole of the part to fit tightly with the reference surface E of the positioning shaft, thereby avoiding positioning errors caused by gaps between the two. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the structure of part 7 in this utility model;

[0048] Figure 2 This is a schematic diagram of the structure of the reference plate 1 in this utility model;

[0049] Figure 3 for Figure 2 Top view;

[0050] Figure 4 This is a schematic diagram of the structure of the distance gauge 2 in this utility model;

[0051] Figure 5 This is a schematic diagram of the positioning shaft 3 in this utility model;

[0052] Figure 6 This is a schematic diagram of the structure of the medium-weight column 4 of this utility model;

[0053] Figure 7 This is a schematic diagram of the positioning seat 5 in this utility model;

[0054] Figure 8 This is a schematic diagram of the structure of this utility model;

[0055] Figure 9 for Figure 8 Top view;

[0056] Figure 10 This is a schematic diagram of the operation of this utility model. Detailed Implementation

[0057] like Figures 1 to 10 As shown, a device for measuring the distance between the bottom surface of a countersunk hole and the lowest point of a circular arc includes a reference plate 1, a distance gauge 2, a positioning shaft 3, a measuring column 4, an L-shaped positioning seat 5, and a base plate 6, wherein:

[0058] The reference plate 1, positioning shaft 3, and positioning seat 5 are fixed on the base plate 6. Specifically, the base plate 6 is provided with multiple threaded holes and pin holes for fixing the base plate 6 to the reference plate 1 and the positioning seat 5. In this embodiment, the four threaded holes and four pin holes on the base plate 6 are spaced apart to ensure that the reference plate 1 and the positioning seat 5 are installed accurately and securely on the base plate 6.

[0059] A positioning hole for fixing the positioning shaft 3 is provided in the middle of the base plate 6. The positioning shaft 3 includes a mounting part 3-2, and the mounting part 3-2 and the positioning hole are interference fit, which can effectively ensure the positional accuracy and stability of the positioning shaft. The positioning shaft 3 also includes a positioning part 3-1, the height of which is H6. The upper surface of the positioning part 3-1 is the reference surface E. The depth of the countersunk hole 7-1 of the part 7 is H1. The diameter of the positioning part 3-1 is larger than the diameter of the mounting part 3-2, and H6 > H1. In this embodiment, the difference between the height H6 of the positioning part 3-1 and the depth H1 of the countersunk hole 7-1 should be controlled within the range of (1~1.5) mm. The upper surface of the reference plate 1 is the reference surface A. The thickness H3 of the reference plate 1 is equal to the height H6 of the positioning part 3-1, so that when the positioning shaft 3 and the reference plate 1 are installed on the base plate 6, the reference surface A of the reference plate 1 and the reference surface E of the positioning shaft 3 are on the same horizontal plane.

[0060] During the measurement process, the positioning part 3-1 of the positioning shaft 3 is engaged with the countersunk hole of the part 7, so that the bottom surface of the countersunk hole (i.e., the reference surface G) of the part is in close contact with the upper surface (i.e., the reference surface E) of the positioning part 3-1 of the positioning shaft 3. Furthermore, the sidewall of the positioning part 3-1 and the sidewall of the countersunk hole 7-1 are in clearance fit. In this embodiment, the diameter of the positioning part 3-1 is typically 1 to 1.2 mm larger than the diameter D0 of the countersunk hole 7-1.

[0061] The positioning seat 5 is fixed on the base plate 6. The positioning seat 5 includes a fixing part 5-2 and an abutment part 5-1 positioned above the fixing part 5-2. The left side wall of the abutment part 5-1 has a reference surface F. During measurement, this reference surface F can abut against the reference surface H of the part 7. More specifically, the distance L4 between the central axis of the positioning shaft 3 and the reference surface F of the positioning seat 5 is less than the distance L1 between the central axis of the countersunk hole 7-1 and the side wall H of the part 7 away from the arc surface. The height H7 of the abutment part 5-1 is equal to the height H2 of the part 7. This prevents the part 7 from tipping over and eliminates gaps through slight compression during abutment, ensuring the consistency of the measurement reference. In this embodiment, the difference between L4 and L1 ranges from (0.15 to 0.3) mm.

[0062] In this embodiment, when the reference plate 1, positioning shaft 3, and positioning seat 5 are fixed on the base plate 6, the center lines of the positioning seat 5, the reference plate 1, and the positioning shaft 3 are all located on the same straight line to prevent offset during assembly of the base plate 6 and ensure the reliability of the measurement. Furthermore, the reference surface F where the positioning seat 5 abuts against the part 7 is perpendicular to the reference surface A of the reference plate 1 and the reference surface E of the positioning shaft 3, with a perpendicularity error not exceeding 0.01 mm.

[0063] The measuring column 4 is set in the arc surface of the part 7. The measuring column 4 includes a measuring column body 4-1 and extensions 4-2 set at both ends of the measuring column body 4-1. The measuring column body 4-1 and the extensions 4-2 are coaxial, and the surface of the extensions 4-2 is provided with a textured structure to enhance friction and facilitate operation.

[0064] The diameter of the extension 4-2 is smaller than the diameter of the measuring column body 4-1, and the diameter of the measuring column body 4-1 is smaller than the diameter of the arc surface of part 7, so that the measuring column can be located at the lowest position of the arc surface during measurement, thereby improving the accuracy of the measurement. In this embodiment, the difference between the diameter of the measuring column body 4-1 and the diameter of the arc surface 7-2 of the part is in the range of (1~1.5) mm.

[0065] The distance gauge 2 includes a gauge body 2-1 and two extensions at both ends of the gauge body 2-1: a go gauge end 2-3 and a no-go gauge end 2-2. The bottom of the gauge body 2-1 slides in contact with the reference surface A of the reference plate 1. During measurement, by observing whether the go gauge end 2-3 and the no-go gauge end 2-2 can pass over the measuring column 4, it can be determined whether the distance between the bottom surface of the countersunk hole of part 7 and the lowest point of the arc meets the specified requirements. Specifically, the bottom surface of the go gauge end 2-3 of the distance gauge 2 is the reference surface C, the bottom surface of the no-go gauge end 2-2 is the reference surface D, and the bottom of the gauge body 2-1 is the reference surface B. The distance between the reference surface C and the reference surface B is greater than the distance between the reference surface D and the reference surface B. The specific relationship is as follows:

[0066] Distance between datum plane C and datum plane B , is the maximum distance from the bottom surface of the countersunk hole of part 7 to the lowest point of the arc. Diameter of the measuring column body 4-1 The sum of ;

[0067] Distance between datum plane D and datum plane B , is the minimum distance from the bottom surface of the countersunk hole of part 7 to the lowest point of the arc. Diameter of the measuring column body 4-1 The sum of .

[0068] The dimension of the reference plate 1 along the length of the base plate 6 is L2, and the dimension of the gauge body 2-1 along the length of the base plate 6 is L3, where L2 > L3. This design effectively prevents the distance gauge 2 from detaching from the reference surface A during movement due to insufficient length of the reference plate 1, thus ensuring the reference stability of the distance gauge 2 during measurement. In this embodiment, the difference between L2 and L3 should be controlled within the range of 20–25 mm.

[0069] It also includes a dial indicator, used to measure the actual distance between the bottom surface of the countersunk hole and the lowest point of the arc on the part.

[0070] It is worth noting that during the manufacturing of this device, the surface roughness Ra of its reference surfaces A, B, C, D, and E should not exceed 0.2 μm, and the flatness of each reference surface should not exceed 0.003 mm, in order to ensure the accuracy of the measurement results.

[0071] The following is a specific embodiment of the above-mentioned device: Example 1

[0072] First, fix the reference plate 1, the positioning shaft 3 and the positioning seat 5 on the base plate 6. Then, vertically place the countersunk hole of the part 7 to be inspected onto the positioning part 3-1 of the positioning shaft 3, so that the bottom surface of the countersunk hole (reference surface G) is in close contact with the upper surface (reference surface E) of the positioning part 3-1.

[0073] Push part 7 so that the right side wall of part 7 (i.e., reference surface H) fits against the reference surface F of the abutment part 5-1 of the positioning seat 5 until part 7 can no longer move to the right.

[0074] Then, place the gauge post 4 into the arc surface 7-2 of the part 7, and place the bottom of the gauge body 2-1 (reference surface B) close to the upper surface (reference surface A) of the reference plate 1. During measurement, move along the reference surface A towards the part, and judge the part's qualification by observing whether the go gauge end 2-3 and the no-go gauge end 2-2 can pass through the top of the gauge post 4. The specific judgment criteria are as follows:

[0075] (1) If the bottom surface of the go gauge end 2-3 of the distance gauge 2 (i.e., the reference surface C) can pass smoothly through the top of the measuring column 4 (i.e., the highest point of the cylinder of the measuring column body 4-1), and the bottom surface of the no-go gauge end 2-2 (i.e., the reference surface D) cannot pass through, then the distance H0 between the bottom surface of the countersunk hole of the part and the lowest point of the arc is between the specified maximum and minimum values, that is, the part is judged to meet the requirements.

[0076] (2) If the bottom surface of the stop gauge end 2-2 (i.e., the reference surface D) and the bottom surface of the go gauge end 2-3 (i.e., the reference surface C) of the distance gauge 2 cannot pass smoothly above the measuring column 4, then the distance H0 between the bottom surface of the countersunk hole of the part and the lowest point of the arc exceeds the specified maximum value, that is, H0 is too large and does not meet the requirements. The arc surface 7-2 needs to be ground until the judgment condition of (1) is met.

[0077] (3) If the bottom surface of the stop gauge end 2-2 of the distance gauge 2 (i.e., the reference surface D) can pass through the top of the measuring column 4, the distance H0 between the bottom surface of the countersunk hole of the part and the lowest point of the arc is less than the specified minimum value, that is, H0 is too small, and it is judged as unqualified and scrapped.

[0078] If the value is smaller than the minimum required for the part, the distance H0 between the bottom surface of the countersunk hole and the lowest point of the arc is too small, and the part is scrapped because it does not meet the requirements. Example 2

[0079] The distance between the bottom surface of the countersunk hole and the lowest point of the arc is measured using a dial indicator. The specific process is as follows:

[0080] Following the steps of Example 1, fix the reference plate 1, positioning shaft 3 and positioning seat 5 on the base plate 6, place the base plate 6 on a flat plate, and use a dial indicator to measure the actual distance H9 from the upper surface (reference surface E) of the positioning part 3-1 of the positioning shaft 3 to the flat plate.

[0081] The countersunk hole of the part 7 to be tested is vertically placed on the positioning part 3-1 of the positioning shaft 3, so that the bottom surface of the countersunk hole (reference surface G) is in close contact with the upper surface of the positioning part 3-1 (i.e., reference surface E). The part 7 is pushed so that the right side wall of the part 7 (i.e., reference surface H) is in contact with the reference surface F of the abutment part 5-1 of the positioning seat 5 until the part 7 can no longer move to the right. The measuring column 4 is then placed into the arc surface 7-2 of the part 7.

[0082] Measure the distance H10 from the highest point of cylinder 4 to the flat plate using a dial indicator, and determine the part's qualification or machining feed rate according to the following criteria:

[0083] (1) If the distance H10 from the highest point of the cylinder 4 to the flat plate satisfies ,in, This refers to the actual distance from the upper surface (i.e., reference surface E) of the positioning part 3-1 of the positioning shaft 3 to the flat plate. This is the maximum distance from the bottom surface of the countersunk hole of part 7 to the lowest point of the arc. The diameter of the measuring cylinder body 4-1, If the diameter of the measuring cylinder body 4-1 is given, it indicates that the distance H0 between the bottom surface of the countersunk hole of part 7 and the lowest point of the arc exceeds the specified maximum value (i.e., H0 is too large), which does not meet the requirements. This can be determined by measuring with a dial indicator. and Adjust the feed rate based on the actual difference between the two values, and continue machining until the result is satisfactory;

[0084] (2) If satisfied ,in, The minimum distance from the bottom surface of the countersunk hole of part 7 to the lowest point of the arc is determined to be the minimum value. At this point, the distance from the bottom surface of the countersunk hole of part 7 to the lowest point of the arc is significantly smaller, and it is judged to be unqualified and scrapped.

[0085] (3) If satisfied If the distance from the bottom of the countersunk hole of part 7 to the lowest point of the arc is within the specified range, it is considered qualified.

[0086] In summary, the device described in this embodiment has a simple structure, is easy to manufacture and operate, and can be used directly on the work site. It can quickly determine whether the measured dimension is qualified by using the distance gauge 2, and can also use a dial indicator to determine whether the measured dimension is qualified while accurately controlling the machining feed rate based on the actual difference, effectively improving the pass rate of part machining. Experimental verification shows that using this device can ensure a 100% pass rate for part machining, and its testing efficiency is improved by more than 5 times compared to traditional measurement methods (such as coordinate measuring machines).

[0087] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications made to the present utility model by those skilled in the art without departing from the spirit of the present utility model shall fall within the protection scope of the present utility model.

Claims

1. A device for measuring the distance of the bottom surface of a counterbore from the lowest point of a circular arc, characterized in that, It includes a reference plate (1), a distance gauge (2), a positioning shaft (3), a measuring column (4), a positioning seat (5), and a base plate (6), wherein: The positioning shaft (3) is fixed on the base plate (6). The positioning shaft (3) is engaged with the countersunk hole of the part (7) so that the bottom surface of the countersunk hole is in close contact with the upper surface of the positioning shaft (3). The reference plate (1) is fixed on the base plate (6) so that the reference surface A of the reference plate (1) and the reference surface E of the positioning shaft (3) are on the same plane. The positioning seat (5) is fixed on the base plate (6). One side of the positioning seat (5) abuts against the side of the part (7). The measuring column (4) is set in the arc surface (7-2) of the part (7). The distance gauge (2) includes a gauge body (2-1) and a go gauge end (2-3) and a no-go gauge end (2-2) extending from the top of the gauge body (2-1) to both ends. The bottom of the gauge body (2-1) slides in contact with the reference surface A of the reference plate (1). During measurement, by observing whether the go gauge end (2-3) and the no-go gauge end (2-2) can pass through the top of the measuring column (4), it is determined whether the distance between the bottom surface of the countersunk hole (7-1) of the part (7) and the lowest point of the arc surface (7-2) meets the requirements.

2. The apparatus of claim 1, wherein, The measuring column (4) includes a measuring column body (4-1) and extensions (4-2) provided at both ends of the measuring column body (4-1). The surface of the extensions (4-2) is provided with a mesh structure. The diameter of the extension (4-2) is smaller than the diameter of the measuring column body (4-1), and the diameter of the measuring column body (4-1) is smaller than the diameter of the arc surface of the part (7).

3. The apparatus of claim 2, wherein, The bottom surface of the go gauge end (2-3) is the reference surface C, the bottom surface of the no-go gauge end (2-2) is the reference surface D, and the bottom of the gauge body (2-1) is the reference surface B. The distance between the reference surface C and the reference surface B is greater than the distance between the reference surface D and the reference surface B. The distance between the reference surface C and the reference surface B is the sum of the maximum value of the distance from the bottom surface of the countersunk hole (7-1) of part (7) to the lowest point of the arc and the diameter of the measuring column body (4-1); The distance between the reference surface D and the reference surface B is the sum of the minimum distance from the bottom surface of the countersunk hole (7-1) of part (7) to the lowest point of the arc and the diameter of the measuring column body (4-1).

4. The apparatus of claim 1, wherein, It also includes a dial indicator, used to measure the actual distance between the bottom surface of the countersunk hole and the lowest point of the arc on the part.

5. The apparatus of claim 1, wherein, The base plate (6) is provided with multiple threaded holes and pin holes for fixed connection between the base plate (6) and the reference plate (1), and between the base plate (6) and the positioning seat (5).

6. The apparatus of claim 1, wherein, The base plate (6) has a positioning hole in the middle for fixing the positioning shaft (3). The positioning shaft (3) includes a mounting part (3-2), and the mounting part (3-2) and the positioning hole are interference fit.

7. The apparatus of claim 6, wherein, The positioning shaft (3) also includes a positioning part (3-1), the diameter of which is greater than the diameter of the mounting part (3-2), and the height of which is greater than the depth of the countersunk hole (7-1).

8. The apparatus of claim 1, wherein, The plane where the positioning seat (5) abuts against the part (7) is a reference plane F, which is perpendicular to the reference plane A of the reference plate (1) and the reference plane E of the positioning shaft (3), and the perpendicularity error is not more than 0.01 mm.

9. The apparatus of claim 1, wherein, The size of the reference plate (1) along the length direction of the bottom plate (6) is greater than the size of the gauge body (2-1) along the length direction of the bottom plate (6).

10. The apparatus of claim 1, wherein, The distance L4 between the central axis of the positioning shaft (3) and the reference plane F of the positioning seat (5) is less than the distance L1 between the central axis of the counterbore (7-1) and the side wall H of the part (7) away from the circular arc surface.

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