A micro deep hole aperture measuring device and method

Abstract

The application discloses a kind of small deep hole aperture measuring device and method, measuring device includes plug gauge body, including clamping positioning part and the concentric step type cylinder structure of measurement correction part composition, measurement correction part is the cylindrical circular truncated cone with taper angle;Measuring method includes: driving the measurement correction part of plug gauge body and inserting into the deep hole inside of the part to be measured;Measure and / or obtain characteristic parameter and plug gauge body leakage height, whether plug gauge body leakage height falls into standard range based on correction scheme, judge whether the size of the deep hole of the part to be measured meets the standard or not.The application will not scratch the surface of deep hole when detecting, effectively reduces the scrap rate and measurement cost;It can batch quickly measure whether the size meets the requirements, and timely find out whether the production equipment is abnormal, effectively reduce the whole detection cost;Plug gauge can ensure effectiveness by periodically retesting size, when wear occurs, it can continue to be used by the way of multiple correction corresponding relationship, so that the inspection method is convenient and effective.

Description

Technical Field

[0001] This invention relates to the field of aperture measurement equipment technology, and in particular to a device and method for measuring the aperture of a micro deep hole. Background Technology

[0002] After some precision parts have completed the remaining structural features (such as planar milling, contour forming, thread tapping, etc.), they need to enter the critical deep hole machining process. This involves using a special ball reamer to mill small-sized deep holes (for example, the hole opening burr removal needs to achieve a MAX R / C0.1 accuracy, the effective hole depth is 10mm, the hole diameter tolerance range is 0.01mm, the maximum hole diameter is 1mm, and the surface roughness requirement at the hole opening is Ra0.2) at a designated position at a preset specific distance from the upper end face of the part. After the part is completed, the diameter at the hole opening needs to be measured. Once a dimensional deviation occurs, it is very likely to cause the product performance to fail or even malfunction. Therefore, it needs to be listed as a key control object in the entire machining process to ensure that the dimensional data meets the design tolerance range.

[0003] Currently, the measurement of micro-hole dimensions mostly uses pin gauges. However, due to the form and position tolerances of high-precision micro-deep holes (such as roundness deviation and coaxiality error), the contact between the pin gauge and the hole wall during inspection is prone to uneven force due to tolerances. This can not only scratch and damage the precision surface of the hole that has already been machined, but also make it impossible to accurately obtain the actual diameter value at the hole opening. When using a projection measuring instrument, the measurement principle relies on optical imaging, which inherently has a certain optical distortion error. The microscopic texture of the hole opening surface will cause the image edge to be blurred, making it difficult to accurately define the hole opening contour boundary. At this time, neither commonly used pin gauges nor projection measuring instruments can meet the dimensional measurement requirements of this type of high-precision micro-deep hole. In addition, when using a coordinate measuring machine, it is necessary to use a probe to set points on the surface to establish a coordinate system for measurement. When the hole position is less than 10mm inside the part, it is difficult to sample and measure the diameter of the deep hole opening. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a device and method for measuring the diameter of a micro-deep hole.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a device for measuring the diameter of a micro-deep hole, comprising: The plug gauge body comprises a concentric stepped column structure consisting of a clamping and positioning part and a measuring and correction part; The bottom of the clamping and positioning part and the top of the measuring and correcting part extend and connect, and the measuring and correcting part is a truncated cylindrical shape with a cone angle; In use, the bottom of the measuring correction part is inserted into the deep hole of the part to be measured, and the positional characteristic parameters of the clamping positioning part and the measuring correction part are measured to determine whether the deep hole size of the part to be measured meets the standard.

[0006] In some embodiments, the cone angle of the measurement correction unit ranges from 0.5 to 1.5°.

[0007] In some embodiments, the length ratio of the measuring correction part to the clamping positioning part is (0.25 to 0.33):1.

[0008] In a second aspect, the present invention also provides a method for measuring the diameter of a micro-deep hole, performed via a micro-deep hole diameter measuring device as described in the first aspect, the measurement method comprising: The clamping and positioning part of the plug gauge body is used to drive the measuring and correction part of the plug gauge body to be inserted into the deep hole of the part to be measured. Measure and / or obtain the first characteristic parameter, the second characteristic parameter, the third characteristic parameter, the fourth characteristic parameter, and the protrusion height of the plug gauge body to form inequalities in the deep hole size compliance range corresponding to different correction schemes; Based on the modified scheme, compare whether the height of the plug gauge body protruding falls within the acceptable range to determine whether the deep hole size of the part to be tested meets the standard.

[0009] In some embodiments, the first feature parameter is: The distance from the position of the measuring correction part diameter corresponding to the sum of the upper limit of the tolerance zone width and the hole diameter to the bottom end face of the clamping and positioning part; or The diameter of the preset distance from the correction part to the bottom end face of the clamping and positioning part.

[0010] In some embodiments, the second feature parameter is: The distance from the position of the measuring correction part diameter corresponding to the sum of the lower limit of the tolerance zone width and the hole diameter to the bottom end face of the clamping and positioning part; or Measure the cone angle at the bottom of the correction section.

[0011] In some embodiments, the third characteristic parameter is the distance from the top end face of the clamping and positioning part to the bottom end face of the clamping and positioning part.

[0012] In some embodiments, the fourth feature parameter is the distance between the starting surface of the deep hole of the part under test and the top end face of the part under test.

[0013] In some embodiments, the protruding height of the plug gauge body is the distance from the top end face of the clamping and positioning part to the top end face of the part to be measured.

[0014] In some embodiments, the step of determining whether the deep hole size of the part under test meets the standard by comparing whether the height of the plug gauge body protrusion falls within the acceptable range based on the modified scheme includes: Determine whether the exposed height of the plug gauge body falls within the acceptable range; If the height of the plug gauge body protruding falls within the acceptable range, it is determined that the deep hole size of the part to be tested has met the standard; if the height of the plug gauge body protruding is not within the acceptable range, it is determined that the deep hole size of the part to be tested has not met the standard.

[0015] The present invention has the following beneficial effects: 1. This invention uses a tapered plug gauge inserted into the deep hole of the part to be tested. By measuring the positional characteristic parameters of the clamping and positioning part and the measuring correction part, it determines whether the deep hole size of the part to be tested meets the standard. During the inspection, the surface of the deep hole will not be scratched, which effectively reduces the scrap rate. Moreover, the small diameter size of the deep hole can be converted into the large height size of the plug gauge. When used with calipers or height gauges, the measurement cost can be effectively reduced. 2. This invention, based on a modified scheme, compares whether the protrusion height of the plug gauge body falls within the acceptable range to determine whether the deep hole size of the part under test meets the standard. It can quickly measure the size at this location in batches to ensure that the requirements are met, promptly detect any abnormalities in the production equipment, effectively reduce the cost of full inspection, and achieve full inspection during production and quality inspection re-inspection during circulation, ensuring that the critical dimensions of the parts can be well guaranteed when production is completed. Moreover, the plug gauge can ensure its effectiveness through periodic re-measurement of dimensions, and when wear occurs, it can continue to be used by using multiple sets of modified corresponding relationships, making the inspection method convenient and effective. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the micro-deep hole diameter measuring device proposed in this invention. Figure 1 ; Figure 2 This is a schematic diagram of the structure of the micro-deep hole diameter measuring device proposed in this invention. Figure 2 ; Figure 3 This is a schematic diagram of the structure of the micro-deep hole diameter measuring device proposed in this invention. Figure 3 ; Figure 4 The measurement principle of the micro-deep hole diameter measuring device proposed in this invention. Figure 1 ; Figure 5 The measurement principle of the micro-deep hole diameter measuring device proposed in this invention. Figure 2 ; Figure 6 The measurement principle of the micro-deep hole diameter measuring device proposed in this invention. Figure 3 ; Figure 7 The measurement principle of the micro-deep hole diameter measuring device proposed in this invention. Figure 4 ; Figure 8 The measurement principle of the micro-deep hole diameter measuring device proposed in this invention. Figure 5 ; Figure 9 The measurement principle of the micro-deep hole diameter measuring device proposed in this invention. Figure 6 ; Figure 10 This is a flowchart illustrating the method for measuring the diameter of a micro-deep hole proposed in this invention. Figure 1 ; Figure 11 This is a flowchart illustrating the micro-deep hole diameter measuring device proposed in this invention. Figure 2 .

[0017] Legend: 1. Plug gauge body; 11. Clamping and positioning part; 12. Measuring and correction part; 2. Parts. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] This application provides a device and method for measuring the diameter of micro-deep holes, solving the problems of commonly used pin gauges damaging the hole opening during inspection and failing to accurately measure the hole size; projection measuring instruments having measurement errors that cannot meet the requirements for size measurement; and coordinate measuring machines requiring probes to establish a coordinate system on the surface, leading to measurement difficulties. This application avoids scratching the surface of deep holes during inspection, effectively reducing scrap rates and measurement costs; it allows for rapid batch measurement of whether the dimensions meet requirements, promptly identifying any abnormalities in production equipment and effectively reducing full inspection costs; the plug gauge's effectiveness can be ensured through periodic remeasurement, and it can continue to be used even when wear occurs by correcting the corresponding relationships in multiple sets, making the inspection method convenient and effective.

[0020] Please refer to the following examples for details: Reference Figure 1 The present invention provides an embodiment of a micro-deep hole diameter measuring device, the specific structure of which includes a plug gauge body 1; wherein, the plug gauge body 1 includes a concentric stepped column structure composed of a clamping and positioning part 11 and a measuring correction part 12, so as to avoid uneven contact between the plug gauge and the deep hole wall during measurement due to eccentricity, thereby causing the hole diameter judgment deviation. For example, the bottom of the clamping and positioning part 11 and the top of the measuring correction part 12 extend and connect, and the connection part adopts an arc transition connection; correspondingly, the measuring correction part 12 is a cylindrical frustum with a cone angle, which can convert the small radial diameter deviation of the deep hole into an easily measurable axial height difference.

[0021] Specifically, the cone angle of the measurement correction unit 12 ranges from 0.5 to 1.5°. In some embodiments, the cone angle of the measurement correction unit 12 ranges from 0.6 to 1.2°. Optionally, in some embodiments, the cone angle of the measurement correction unit 12 ranges from 0.8 to 1.2°. Preferably, the cone angle of the measurement correction unit 12 is 1.0°. Exemplarily, the cone angle range of the measurement correction unit 12 is 0.8°, 0.9°, 1.0°, 1.1°, 1.2°, or any combination of two of the above values.

[0022] Understandably, in practical applications, a fixed cone angle can be selected based on the actual tolerance requirements of the deep hole. For example, when the hole diameter tolerance is 0.01 mm, the cone angle is 1.0°.

[0023] Correspondingly, the length ratio of the measuring correction part 12 to the clamping positioning part 11 is (0.25 to 0.33):1. In some embodiments, the length ratio of the measuring correction part 12 to the clamping positioning part 11 is (0.25 to 0.30):1. Optionally, in some embodiments, the length ratio of the measuring correction part 12 to the clamping positioning part 11 is (0.25 to 0.30):1. Exemplarily, the cone angle range of the measuring correction part 12 is 0.25:1, 0.26:1, 0.27:1, 0.28:1, 0.29:1, 0.30:1, or any two of the above values.

[0024] Understandably, if the measuring correction part 12 is too long, it will cause the center of gravity of the plug gauge to be biased towards the inside of the deep hole. Especially when the deep hole is located less than 10mm inside the part 2, the tilt will directly cause the contact position between the hole opening and the taper surface of the plug gauge to shift, resulting in measurement error. If the measuring correction part 12 is too short, its contact area with the wall of the deep hole will be insufficient, and it will not be able to accurately reflect the overall size of the hole diameter.

[0025] Understandably, in practical applications, a fixed ratio within this range can be selected, or the ratio can be adjusted to any two values ​​based on the overall size of part 2 to adapt to the clamping space requirements of different parts 2.

[0026] Reference Figures 4-11 The present invention also provides an embodiment of a method for measuring the diameter of a micro-deep hole, which is performed via the micro-deep hole diameter measuring device as described in the above embodiment, and the measurement method includes: The clamping and positioning part 11 of the plug gauge body 1 is used to drive the measuring and correction part 12 of the plug gauge body 1 to be inserted into the deep hole of the part to be measured 2. Measure and / or obtain the first characteristic parameter, the second characteristic parameter, the third characteristic parameter, the fourth characteristic parameter, and the leakage height of the plug gauge body 1 to form inequalities in the deep hole size compliance range corresponding to different correction schemes; Based on the modified scheme, compare whether the protrusion height of the plug gauge body 1 falls within the acceptable range, and determine whether the deep hole size of the part to be tested 2 meets the standard.

[0027] Please continue reading. Figures 4-9 After the deep hole machining of the part to be tested 2 is completed, the plug gauge of this application is required to measure the size: that is, after the deep hole machining of the part to be tested 2 is completed, the bottom of the measuring correction part 12 of the plug gauge is inserted into the deep hole of the part to be tested 2, and the positional characteristic parameters of the clamping positioning part 11 and the measuring correction part 12 are measured to determine whether the deep hole size of the part to be tested 2 meets the standard. Understandably, the gauge does not scratch the surface of deep holes during inspection, effectively reducing the scrap rate. Furthermore, it can convert the small diameter of deep holes into the large height of the plug gauge. Compared to traditional pin gauges, the plug gauge in this application can quantify the specific value of the hole diameter through parameter calculation. Moreover, the tapered surface of the plug gauge makes surface contact with the hole wall (rather than the line contact of a pin gauge), effectively dispersing contact pressure and avoiding scratching the surface of deep holes (especially the high-gloss area of ​​Ra0.2 at the hole opening), thereby effectively reducing the scrap rate of part 2. Simultaneously, it can convert the small diameter of deep holes into the large height of the plug gauge, eliminating the need for a coordinate measuring machine; inspection can be completed simply by using conventional calipers or height gauges, effectively reducing the investment cost of measurement equipment on the production line. This is particularly suitable for the full inspection requirements of small to medium batches of part 2.

[0028] For example, the diameter of the deep hole in the part to be tested 2 is 0.80 mm. Figure 1 D1 in the figure), the distance between the starting surface of the deep hole of the part to be tested 2 and the top end face of the part to be tested 2 ( Figure 2 H1) is 9.00 mm, and the distance from the starting face of the deep hole to the bottom face of the deep hole of the part to be tested 2 is ( Figure 2 H2) is 10.00 mm, and the tolerance zone is required to be 0.01-0.02 mm; Correspondingly, the total length of the plug gauge body 1 ( Figure 2 L1 in the measurement section is 45mm, and the total length of the measuring correction section 12 is ( Figure 2 L2 in the figure is 10.3 mm, and the diameter of the measuring correction part 12 corresponding to the sum of the upper limit of the tolerance zone width (0.02 mm) and the hole diameter (0.80 mm) (0.82 mm) is ( Figure 2 The distance from position D2 to the bottom end face of the clamping and positioning part 11 ( Figure 2 The middle part is L3); the diameter of the measuring correction part 12 corresponding to the sum of the lower limit of the tolerance zone width (0.01mm) and the hole diameter (0.80mm) (0.81mm) is ( Figure 2The distance from position D3 to the bottom end face of the clamping and positioning part 11 ( Figure 2 L4 is the middle value); the cone angle of the measuring correction unit 12 is ( Figure 2 (α) is 1.0°; It needs to be explained in detail that, according to the tolerance zone requirements, the calculated axial height corresponding to a radial deviation of 0.01mm is 0.573mm. Therefore, it can be concluded that: using a height gauge or similar equipment to measure the height from the top of the plug gauge to the top of part 2 (within... Figure 3 When the height is H), the deep hole size of the part to be tested 2 is considered to meet the standard when the height is between 27.200-27.772mm. Furthermore, due to factors such as tool wear and machine vibration during the machining of part 2, there may be slight differences between the design drawing parameters of the plug gauge and the actual parameters of part 2 after machining. If the design parameters are used directly to calculate the acceptable range, it is easy to lead to misjudgment. Therefore, before measuring each batch of part 2, the parameters need to be corrected by measurement. At the same time, during long-term use, the tapered surface of the measuring correction part 12 of the plug gauge may experience slight wear due to repeated contact with the hole wall. Therefore, it is necessary to calibrate regularly and update the height-hole diameter reference range table according to the wear condition. Even if the plug gauge shows slight wear, it does not need to be scrapped directly. By adding multiple sets of correction correspondences, its measurement accuracy can be maintained and its service life extended.

[0029] Understandably, by comparing the height of the plug gauge body 1 with the standard range based on the correction scheme, it can be determined whether the deep hole size of the part to be tested 2 meets the standard. This allows for rapid batch measurement of the size to ensure it meets the requirements, timely detection of any abnormalities in the production equipment, and effective reduction of full inspection costs. It enables full inspection during production and quality inspection during circulation, ensuring that the key dimensions of part 2 are well guaranteed when production is completed. Furthermore, the plug gauge can ensure its effectiveness through periodic dimensional re-measurement, and when wear occurs, it can continue to be used through multiple sets of correction relationships, making the inspection method convenient and effective.

[0030] Please continue reading. Figures 1-6 In this embodiment: First characteristic parameter (in) Figure 4 , Figure 6 and Figure 8 Parameter A is the distance from the diameter position of the measuring correction part 12 to the bottom end face of the clamping and positioning part 11, corresponding to the sum of the upper limit of the tolerance zone width (0.02mm) and the hole diameter (0.80mm) (0.82mm). Figure 4 and Figure 8 (A is in the middle); or measure the diameter of the preset distance from the correction part 12 to the bottom end face of the clamping and positioning part 11 (in Figure 6 (A is in the middle).

[0031] Furthermore, the second characteristic parameter (in Figure 4 , Figure 6 and Figure 8 Parameter B is the distance from the diameter position of the measuring correction part 12 to the bottom end face of the clamping and positioning part 11 corresponding to the sum of the lower limit of the tolerance zone width (0.01mm) and the hole diameter (0.80mm) (0.81mm). Figure 4 (B is in the middle); or measure the cone angle at the bottom of the correction part 12 (in Figure 6 and Figure 8 (B is in the middle).

[0032] Correspondingly, the third feature parameter (in Figure 4 , Figure 6 and Figure 8 (C) is the distance from the top end face of the clamping and positioning part 11 to the bottom end face of the clamping and positioning part 11; In addition, the fourth characteristic parameter (in Figure 5 , Figure 7 and Figure 9 The parameter D is the distance between the starting surface of the deep hole of the part to be tested 2 and the top end face of the part to be tested 2.

[0033] Additionally, the exposed height of the plug gauge body 1 (in) Figure 5 , Figure 7 and Figure 9 (H) is the distance from the top end face of the clamping and positioning part 11 to the top end face of the part to be measured 2.

[0034] Please continue reading. Figures 4-11 In this embodiment, determining whether the deep hole size of the part to be tested 2 meets the standard by comparing whether the protrusion height of the plug gauge body 1 falls within the acceptable range based on the modified scheme includes: Determine whether the protrusion height of the plug gauge body 1 falls within the acceptable range; If the height of the plug gauge body 1 protruding falls within the acceptable range, it is determined that the deep hole size of the part to be tested 2 has met the standard; if the height of the plug gauge body 1 protruding is not within the acceptable range, it is determined that the deep hole size of the part to be tested 2 has not met the standard.

[0035] Correction principle: Example 1: Please continue reading. Figures 4-5 In this embodiment, the first feature parameter A is the distance from the diameter position of the measuring correction part 12 corresponding to the sum of the upper limit of the tolerance band width and the hole diameter to the bottom end face of the clamping positioning part 11; the second feature parameter B is the distance from the diameter position of the measuring correction part 12 corresponding to the sum of the lower limit of the tolerance band width and the hole diameter to the bottom end face of the clamping positioning part 11; the third feature parameter C is the distance from the top end face of the clamping positioning part 11 to the bottom end face of the clamping positioning part 11; and the fourth feature parameter D is the distance from the top end face of the clamping positioning part 11 to the top end face of the part 2 to be measured. At this point, the acceptable range for the height H from the top of the plug gauge to the top of part 2 is: C-D+A <H<C-D+B; Example 2: Please continue reading. Figures 6-7 In this embodiment, the first feature parameter A is the diameter of the preset distance (1.5 mm in this application) from the measuring correction part 12 to the bottom end face of the clamping positioning part 11; the second feature parameter B is the bottom cone angle of the measuring correction part 12; the third feature parameter C is the distance from the top end face of the clamping positioning part 11 to the bottom end face of the clamping positioning part 11; and the fourth feature parameter D is the distance from the top end face of the clamping positioning part 11 to the top end face of the part 2 to be measured. At this point, the acceptable range for the height H from the top of the plug gauge to the top of part 2 is: C + 1.5 - D + (A - 0.82) / B <H<C+1.5-D+(A-0.81) / B; Example 3: Please continue reading. Figures 8-9 In this embodiment, the first feature parameter A is the distance from the diameter position of the measuring correction part 12 corresponding to the sum of the upper limit of the tolerance zone width and the hole diameter to the bottom end face of the clamping positioning part 11; the second feature parameter B is the bottom cone angle of the measuring correction part 12; the third feature parameter C is the distance from the top end face of the clamping positioning part 11 to the bottom end face of the clamping positioning part 11; and the fourth feature parameter D is the distance from the top end face of the clamping positioning part 11 to the top end face of the part 2 to be measured. At this point, the acceptable range for the height H from the top of the plug gauge to the top of part 2 is: C-D+A <H<C-D+A-0.01 / B; It should be noted that the above calibration measurement method can also be performed using a coordinate measuring machine or a projection measuring machine, and the angle should be based on the range of use. For example, if the diameter a corresponds to the distance h1 from the end face, and the diameter b corresponds to the distance h2, and the acceptable range of the diameter difference corresponds to the height difference, then the angle to be measured should be between the sampling distance and the height difference at the end face.

[0036] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for measuring the diameter of a micro-deep hole, characterized in that, The measurement method includes: The clamping and positioning part of the plug gauge body is used to drive the measuring and correction part of the plug gauge body to be inserted into the deep hole of the part to be measured. Measure and / or obtain the first characteristic parameter, the second characteristic parameter, the third characteristic parameter, the fourth characteristic parameter, and the protrusion height of the plug gauge body to form inequalities in the deep hole size compliance range corresponding to different correction schemes; The first feature parameter is: The distance from the position of the measuring correction part diameter corresponding to the sum of the upper limit of the tolerance zone width and the hole diameter to the bottom end face of the clamping and positioning part; or The diameter of the distance from the preset distance between the measuring correction part and the bottom end face of the clamping and positioning part; The second feature parameter is: The distance from the position of the measuring correction part diameter corresponding to the sum of the lower limit of the tolerance zone width and the hole diameter to the bottom end face of the clamping and positioning part; or Measure the cone angle at the bottom of the correction section; The third characteristic parameter is the distance from the top end face of the clamping and positioning part to the bottom end face of the clamping and positioning part; The fourth characteristic parameter is the distance between the starting surface of the deep hole of the part under test and the top end face of the part under test; Based on the modified scheme, the protrusion height of the plug gauge body is compared to see if it falls within the acceptable range to determine whether the deep hole size of the part under test meets the standard, including: Determine whether the exposed height of the plug gauge body falls within the acceptable range; If the height of the plug gauge body protruding falls within the acceptable range, it is determined that the deep hole size of the part to be tested has met the standard; if the height of the plug gauge body protruding is not within the acceptable range, it is determined that the deep hole size of the part to be tested has not met the standard.

2. The method for measuring the diameter of a micro-deep hole according to claim 1, characterized in that, The protruding height of the plug gauge body is the distance from the top end face of the clamping and positioning part to the top end face of the part to be measured.

3. A device for measuring the diameter of a micro-deep hole, comprising the method for measuring the diameter of a micro-deep hole as described in any one of claims 1-2, characterized in that, include: The plug gauge body comprises a concentric stepped column structure consisting of a clamping and positioning part and a measuring and correction part; The bottom of the clamping and positioning part and the top of the measuring and correcting part extend and connect, and the measuring and correcting part is a truncated cylindrical shape with a cone angle; In use, the bottom of the measuring correction part is inserted into the deep hole of the part to be measured, and the positional characteristic parameters of the clamping positioning part and the measuring correction part are measured to determine whether the deep hole size of the part to be measured meets the standard.

4. The micro-deep hole diameter measuring device according to claim 3, characterized in that, The cone angle range of the measurement correction unit is 0.5° to 1.5°.

5. The micro-deep hole diameter measuring device according to claim 3, characterized in that, The length ratio of the measuring correction part to the clamping and positioning part is (0.25~0.33):1.

Images