Deep hole rifling depth detection method

Abstract

The present invention discloses a deep hole rifling depth detection method, comprising the following steps: Step 1: Acquiring measurement data: 11) Installing a spectral confocal displacement sensor on a mounting shaft parallel to the axis of a pipe to be tested, so that the spectral confocal displacement sensor is extended into a set position of the pipe to be tested, and then keeping the spectral confocal displacement sensor stationary and the axial speed of the pipe to be tested zero; 12) Driving the pipe to be tested to rotate around the mounting shaft at a uniform speed for one circle. During the rotation of the pipe to be tested, the spectral confocal displacement sensor is used to measure the inner wall of the pipe to be tested, and a curve reflecting the change of the distance between the inner wall of the pipe to be tested and the spectral confocal displacement sensor over time is obtained; Step 2: Acquiring the rifling depth: Fitting all wave crest segments into a first sine curve, and fitting all wave trough segments into a second sine curve, then the rifling depth is obtained: #imgabs0#, #imgabs1# and #imgabs2# respectively represent the offset distances of the first sine curve and the second sine curve.

Description

Technical Field

[0001] The invention belongs to the technical field of non-destructive testing, and specifically relates to a method for detecting the depth of a deep hole rifling. Background Art

[0002] The depth and uniformity of the rifling along the length of the barrel are important parameters affecting barrel performance. Currently, rifling depth detection at different locations in a deep hole is divided into three steps: 1) Divide the deep hole part into n equal parts and move the detection element to the positions of n+1 deep hole sections; 2) Detect and calculate the positive and negative centers or positive and negative diameters of each deep hole section; 3) Calculate the rifling depth.

[0003] At present, most deep hole rifling depth detection methods are to calculate the rifling depth by measuring the female rifling diameter and male rifling diameter of the deep hole. The main instruments for measuring the male rifling diameter include mechanical star calipers, optical star calipers, inductive calipers, deep hole inner diameter micrometers, etc. The female rifling diameter at the mouth is relatively easy to measure, but it is difficult to directly measure the female rifling diameter at the deep hole. Moreover, during the detection process, these methods and instruments are prone to mutual wear between the auxiliary detection elements in contact with the inner hole and the inner hole of the workpiece, and have the disadvantages of low efficiency and cumbersome operation. Summary of the Invention

[0004] In view of this, an object of the present invention is to provide a deep hole rifling depth detection method, which can conveniently measure the deep hole rifling depth and has the advantages of simple operation and good reliability.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A method for detecting the depth of a deep hole rifling comprises the following steps:

[0007] Step 1: Get measurement data:

[0008] 11) Install the spectral confocal displacement sensor on a mounting shaft parallel to the axis of the pipe to be tested, drive the spectral confocal displacement sensor and the pipe to be tested to move relative to each other along the axis of the pipe to be tested, and after the spectral confocal displacement sensor is inserted into the set position of the pipe to be tested, keep the spectral confocal displacement sensor stationary and the axial speed of the pipe to be tested zero;

[0009] 12) The pipe to be tested is driven to rotate uniformly around the mounting axis for one circle. During the rotation of the pipe to be tested, the inner wall of the pipe to be tested is measured using the spectral confocal displacement sensor, and a curve is obtained reflecting the change in the distance between the inner wall of the pipe to be tested and the spectral confocal displacement sensor over time;

[0010] Step 2: Get the Rifling Depth

[0011] In the obtained distance-time curve, there are peak segments reflecting the distances between different negative lines and the spectral confocal displacement sensor and trough segments reflecting the distances between different positive lines and the spectral confocal displacement sensor, and the peak segments and trough segments appear alternately;

[0012] Fitting all peak segments to the first sine curve yields:

[0013]

[0014] Fitting all the trough segments to the second sine curve yields:

[0015]

[0016] in, represents the sine curve obtained by fitting the peak segment; represents the sine curve obtained by fitting the trough segment; Indicates time; Indicates amplitude; represents angular velocity; Indicates the initial phase; and Indicates offset;

[0017] The average value of the rifling depth on the radial section where the spectral confocal displacement sensor is located is: .

[0018] Furthermore, the method further includes step three: looping through steps one and two to obtain the average value of the rifling depth at different positions of the pipe to be tested, and making a spline curve using the average value of the rifling depth at all positions to determine the change in the rifling depth at any position of the pipe to be tested.

[0019] Furthermore, the time interval for collecting data by the spectral confocal displacement sensor is satisfy:

[0020]

[0021] in, It represents the smaller arc length between the positive line and the negative line on the radial section; Indicates the maximum distance between the spectral confocal displacement sensor and the negative line or positive line, and:

[0022] When the arc length of the Yang line on the radial section is small, , Indicates the curvature radius of the Yang line;

[0023] When the arc length of the negative line on the radial section is small, , Indicates the curvature radius of the shadow line.

[0024] The beneficial effects of the present invention are:

[0025] The deep hole rifling depth detection method of the present invention only requires, during measurement, to insert the spectral confocal displacement sensor into the pipe to be measured along the axial direction, drive the pipe to be measured to rotate uniformly around the installation axis (i.e., the axis of the spectral confocal displacement sensor), and use the spectral confocal displacement sensor to measure and obtain a curve reflecting the change of the distance between the inner wall of the pipe to be measured and the spectral confocal displacement sensor over time; in the radial cross section of the pipe to be measured, the positive line and the negative line are respectively located on two coaxial circles. Therefore, when there is eccentricity between the spectral confocal displacement sensor and the axis of the pipe to be measured, When the pipe to be tested rotates at a constant speed, the change in the distance between the positive line and the spectral confocal displacement sensor can be fitted into a first sinusoidal curve. Similarly, the change in the distance between the negative line and the spectral confocal displacement sensor can also be fitted into a second sinusoidal curve. Since the rotation period and initial phase of the pipe to be tested are the same, and the amplitude of the fitted sinusoidal curve is related to the bending deformation of the workpiece, of course, when the bending deformation of the workpiece is 0), without considering the vibration of the pipe to be tested during rotation, the amplitude A is 0; therefore, in the sinusoidal curves obtained by fitting the positive line and the negative line, the amplitude , angular velocity and initial phase are equal, only the positive and negative lines are offset from the spectral confocal displacement sensor and Different, so you can get the depth of the rifling During the measurement process, there is no need to worry about the radial position of the spectral confocal displacement sensor within the pipe to be measured. As long as the pipe to be measured does not interfere with the spectral confocal displacement sensor during rotation, the measurement is simple. During the measurement process, the spectral confocal displacement sensor does not come into contact with the pipe to be measured, which will not affect the test results and has higher reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to make the purpose, technical solutions and beneficial effects of the present invention more clear, the present invention provides the following drawings for illustration:

[0027] Figure 1 This is a structural diagram of the spectral confocal displacement sensor when it is inserted into the pipe to be tested;

[0028] Figure 2 This is a radial cross-sectional view of the pipe to be tested at the location of the spectral confocal displacement sensor.

[0029] 1- pipe to be tested; 2- spectral confocal displacement sensor; 3- rotating shaft; 4- positive line; 5- negative line. DETAILED DESCRIPTION

[0030] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0031] The deep hole rifling depth detection method of this embodiment includes the following steps:

[0032] Step 1: Get measurement data:

[0033] 11) Install the spectral confocal displacement sensor on a mounting shaft parallel to the axis of the pipe to be tested, drive the spectral confocal displacement sensor and the pipe to be tested to move relative to each other along the axis of the pipe to be tested, and after the spectral confocal displacement sensor is inserted into the set position of the pipe to be tested, keep the spectral confocal displacement sensor stationary and the axial speed of the pipe to be tested zero;

[0034] 12) The pipe to be tested is driven to rotate uniformly around the mounting axis for one circle. During the rotation of the pipe to be tested, the inner wall of the pipe to be tested is measured using the spectral confocal displacement sensor, and a curve is obtained reflecting the change in the distance between the inner wall of the pipe to be tested and the spectral confocal displacement sensor over time;

[0035] Step 2: Get the Rifling Depth

[0036] In the obtained distance-time curve, there are peak segments reflecting the distances between different negative lines and the spectral confocal displacement sensor and trough segments reflecting the distances between different positive lines and the spectral confocal displacement sensor, and the peak segments and trough segments appear alternately;

[0037] Fitting all peak segments to the first sine curve yields:

[0038]

[0039] Fitting all the trough segments to the second sine curve yields:

[0040]

[0041] in, represents the sine curve obtained by fitting the peak segment; represents the sine curve obtained by fitting the trough segment; Indicates time; Indicates amplitude; represents angular velocity; Indicates the initial phase; and Indicates offset;

[0042] The average value of the rifling depth on the radial section where the spectral confocal displacement sensor is located is:

[0043] .

[0044] In a preferred embodiment of this embodiment, step three is also included: looping through steps one and two to obtain the average value of the rifling depth at different positions of the pipe to be tested. (i=1,2,3...n), the average value of the rifling depth at all positions Make a spline curve to determine the change in rifling depth at any position of the pipe to be tested.

[0045] Specifically, the spectral confocal displacement sensor has a time interval between each two data acquisitions. , the time interval for collecting data by the spectral confocal displacement sensor satisfy:

[0046]

[0047] in, It represents the smaller arc length between the positive line and the negative line on the radial section; Indicates the maximum distance between the spectral confocal displacement sensor and the negative line or positive line, and:

[0048] When the arc length of the Yang line on the radial section is small, , Indicates the curvature radius of the Yang line;

[0049] When the arc length of the negative line on the radial section is small, , Indicates the curvature radius of the shadow line.

[0050] In the deep hole rifling depth detection method of this embodiment, during measurement, it is only necessary to insert the spectral confocal displacement sensor into the pipe to be tested along the axial direction, drive the pipe to be tested to rotate uniformly around the installation axis (i.e., the axis of the spectral confocal displacement sensor), and use the spectral confocal displacement sensor to measure a curve reflecting the change in the distance between the inner wall of the pipe to be tested and the spectral confocal displacement sensor over time; in the radial cross section of the pipe to be tested, the positive line and the negative line are respectively located on two coaxial circles. Therefore, when there is eccentricity between the spectral confocal displacement sensor and the axis of the pipe to be tested, When the pipe to be tested rotates at a constant speed, the change in the distance between the positive line and the spectral confocal displacement sensor can be fitted into a sine curve. Similarly, the change in the distance between the negative line and the spectral confocal displacement sensor can also be fitted into a sine curve. Since the rotation period and initial phase of the pipe to be tested are the same, and the amplitude of the fitted sine curve is related to the bending deformation of the workpiece, of course, when the bending deformation of the workpiece is 0), without considering the vibration of the pipe to be tested during rotation, the amplitude A is 0; therefore, in the sine curves obtained by fitting the positive and negative lines, the amplitude , angular velocity and initial phase are equal, only the positive and negative lines are offset from the spectral confocal displacement sensor and Different, so that the average depth of the rifling can be obtained During the measurement process, there is no need to worry about the radial position of the spectral confocal displacement sensor within the pipe to be measured. As long as the pipe to be measured does not interfere with the spectral confocal displacement sensor during rotation, the measurement is simple. During the measurement process, the spectral confocal displacement sensor does not come into contact with the pipe to be measured, which will not affect the test results and has higher reliability.

[0051] The above embodiments are merely preferred embodiments for the purpose of fully illustrating the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are within the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

Claims

1. A method for detecting the depth of a deep hole rifling, characterized in that: The steps include: Step 1: Get measurement data: 11) Install the spectral confocal displacement sensor on a mounting shaft parallel to the axis of the pipe to be tested, drive the spectral confocal displacement sensor and the pipe to be tested to move relative to each other along the axis of the pipe to be tested, and after the spectral confocal displacement sensor is inserted into the set position of the pipe to be tested, keep the spectral confocal displacement sensor stationary and the axial speed of the pipe to be tested zero; 12) The pipe to be tested is driven to rotate uniformly around the mounting axis for one circle. During the rotation of the pipe to be tested, the inner wall of the pipe to be tested is measured using the spectral confocal displacement sensor, and a curve is obtained reflecting the change in the distance between the inner wall of the pipe to be tested and the spectral confocal displacement sensor over time; Step 2: Get the rifling depth In the obtained distance-time curve, there are peak segments reflecting the distances between different negative lines and the spectral confocal displacement sensor and trough segments reflecting the distances between different positive lines and the spectral confocal displacement sensor, and the peak segments and trough segments appear alternately; Fitting all peak segments to the first sine curve yields: Fitting all the trough segments to the second sine curve yields: in, represents the sine curve obtained by fitting the peak segment; represents the sine curve obtained by fitting the trough segment; Indicates time; Indicates amplitude; represents angular velocity; Indicates the initial phase; and Indicates offset; The average value of the rifling depth on the radial section where the spectral confocal displacement sensor is located is: .

2. The deep hole rifling depth detection method according to claim 1, characterized in that: The method further includes step three: looping through steps one and two to obtain the average value of the rifling depth at different positions of the pipe to be tested, and making a spline curve using the average value of the rifling depth at all positions to determine the change in the rifling depth at any position of the pipe to be tested.

3. The deep hole rifling depth detection method according to claim 2, characterized in that: The time interval for collecting data by the spectral confocal displacement sensor satisfy: in, It represents the smaller arc length between the positive line and the negative line on the radial section; Indicates the maximum distance between the spectral confocal displacement sensor and the negative line or positive line, and: When the arc length of the Yang line on the radial section is small, , Indicates the curvature radius of the Yang line; When the arc length of the negative line on the radial section is small, , Indicates the curvature radius of the shadow line.

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