A pressure vessel head roundness measurement method and device

Abstract

The present invention discloses a method and device for measuring the roundness of a pressure vessel head. The method uses a roundness measuring device to rotate and scan along the end face of the head at every angle to obtain the distance to the inner wall of the head, obtain the center position of the end face of the head according to the distance of the fixed detection point, and combine the distance between each detection point and the center of the circle to achieve roundness measurement; the device includes a support rod, a cushion block and a distance scanning detection component, the distance scanning detection component is composed of a rotating device and a distance detection device, the rotating device in the distance scanning detection component is installed on the support rod, and the distance detection device is installed on the rotating device. The present invention has no positioning requirements in the head and is a non-contact measurement, which eliminates the need for positioning and contact measurement for the traditional pressure vessel head roundness detection. The operation is very simple and convenient, and the detection efficiency is high; it also avoids the errors caused by positioning and contact, and has higher accuracy and reliability.

Description

Technical Field

[0001] The invention relates to a roundness measuring method and device in the technical field of pressure-bearing container detection, and in particular to a roundness measuring method and device for a rotationally symmetrical end face of a pressure vessel head. Background Art

[0002] The head is one of the main pressure-bearing components of pressure vessels and is widely used in the process of vessel manufacturing. The roundness of the head end face is a key point in the head parameter inspection. The current GB / T25198-2010 "Pressure Vessel Head" standard specification has put forward regulations and requirements for the roundness of the head, and the head manufacturer must test the roundness of the head end face.

[0003] Usually, when testing the roundness of the end cap, a manual method is often used, using a steel tape measure to measure multiple diameters through the center of the end face, record the diameter difference and get the roundness based on it. This method leads to high workload and requires the assistance of multiple people; since the judgment of the center of the circle and the reading of the tape measure data are all manual methods, this method has low accuracy and many disadvantages.

[0004] In addition, there are also many patents that propose roundness measurement methods or devices for heads or similar rotationally symmetrical objects. Patent CN102706260 improves the steel tape measure and uses a block to make the steel tape measure contact with the object to be measured for measurement; Patent CN113358054 uses a retractable bracket to locate the center of rotation to the center of the circle according to the inner diameter of the object to be measured, and then performs roundness measurement. Patent CN202994105 uses a total station to collect three-dimensional data of the object to be measured in a non-contact manner, and extracts roundness data based on this. These patents either use non-contact measurement to obtain three-dimensional data for roundness detection, in which case the amount of data is large and complex; or they use contact to detect the roundness of the object to be measured. In this case, the detection device needs to be positioned to the center of the circle for measurement. The problem is that the contact error is large, and the detection process is cumbersome and inconvenient to use. Summary of the invention

[0005] In view of the shortcomings of the existing method for detecting the roundness of the pressure vessel head, the present invention proposes a method and device for measuring the roundness of the pressure vessel head, which can be used to measure the roundness of the head end face, solves the problems of the existing roundness detection method, such as the cumbersome detection process and inconvenient use, and solves the problems of the existing roundness detection device requiring positioning and the errors caused by positioning.

[0006] The present invention adopts the following technical solution:

[0007] 1. A method for measuring the roundness of a pressure vessel head, the method steps are as follows:

[0008] 1) Use the distance scanning detection component to rotate and scan one circle along the circumference of the end face of the end cap from the initial position, and obtain the distance between the distance scanning detection component and the corresponding detection point on the inner wall surface of the end cap, and the cumulative center angle value between the distance scanning detection component and the detection point corresponding to the initial position at multiple locations of the angle rotation scanning;

[0009] 2) Select a detection point scanned by the distance scanning detection component as the reference point, and select four distance values ​​O'A, O'B, O'A', O'B' between the distance scanning detection component and the corresponding detection point on the inner wall surface of the head when the cumulative center angles between the reference points are converted to 0°, 90°, 180°, and 270° respectively from the multiple distances obtained in step 1);

[0010] 3) determining the center position of the end face of the end cap according to the four distance values ​​obtained in step 2);

[0011] 4) processing the distances between the detection points of each distance and the center of the circle obtained in step 3) according to the multiple distances obtained in step 1) and the accumulated center angle values ​​converted to the reference points;

[0012] 5) The roundness of the end face of the end cap is determined based on the distance between the detection points at various distances and the center of the circle obtained in step 3).

[0013] By adjusting the different heights of the pads, when the distance scanning detection component rotates and scans along the end face of the head, the detection point corresponding to the inner wall surface of the head is scanned in the straight edge area of ​​the head. The straight edge area of ​​the head and the end face have the same roundness and basically the same diameter.

[0014] In step 2), the point from the initial position of the distance scanning detection component to the inner wall surface of the end cap is selected as the reference point. The reference point can be the detection point corresponding to the initial position of the distance detection device, or the detection point corresponding to any position in the rotation scanning of the distance detection device.

[0015] During roundness testing, the pressure vessel head roundness measuring device is placed arbitrarily on the head end surface through support rods and pads without any positioning requirements.

[0016] The bottom surface of the support rod is parallel to the end surface of the pressure vessel head through an equal height pad, and the rotation scanning direction of the distance detection equipment is parallel to the bottom surface of the support rod, and then parallel to the end surface of the pressure vessel head.

[0017] In step 3), the angle θ between the direction from the center O of the end face of the end cap to the reference point O' measured by the distance detection device and the direction O'A and the distance l from the center O of the end face of the end cap to the reference point O' measured by the distance detection device are determined according to the following formula:

[0018]

[0019] Among them, point O' is the reference point when the distance detection equipment is measuring, and points A, B, A', and B' are four detection points on the inner wall of the head along the end face direction of the pressure vessel head when the distance detection equipment rotates 90° clockwise or counterclockwise;

[0020] Then, the center position of the end face of the end cap is determined in real time according to the angle θ and the distance l.

[0021] In step 4), the distance r between any detection point C and the center point O of the end face of the end cap is obtained according to the following formula, which is used as the radius r at the detection point:

[0022]

[0023] Wherein, m is the detection distance from the reference point O' to the detection point C measured by the distance scanning detection component, l is the distance from the reference point O' to the end face center O measured by the distance scanning detection component, θ is the angle between the direction from the reference point O' to the end face center O measured by the distance scanning detection component and the direction O'A, and ω is the cumulative angle when the distance scanning detection component rotates from the reference point O' to the detection point C.

[0024] The roundness of step 5) is calculated as:

[0025] δ=(r max -r min ) / r ave

[0026] In the formula, r max r is the maximum radius of each detection point during a rotation scan of the distance scanning detection component along the end face of the head, min is the minimum radius of each detection point, r ave is the average radius of each detection point.

[0027] 2. A pressure vessel head roundness measuring device:

[0028] The pressure vessel head roundness measuring device comprises a support rod, a cushion block and a distance scanning detection component; both ends of the support rod are supported by the cushion blocks and placed on both sides of the head end surface, and a rotatable distance scanning detection component is installed at the bottom of the support rod.

[0029] The bottom surface of each end of the support rod is placed on a cushion block, and the cushion block is placed on the end surface of the head.

[0030] The distance scanning detection component is mainly composed of a distance detection device and a rotating device. The distance detection device is rotatably mounted on the support rod through the rotating device.

[0031] The rotating axis of the rotating device is perpendicular to the bottom surface of the support rod and also perpendicular to the optical axis of the distance detection device, and the two axes intersect at one point.

[0032] According to the device of the present invention, the distance detecting device is arranged parallel to the end face of the pressure vessel head. The rotation scanning direction of the distance detecting device along the end face of the pressure vessel head is parallel to the support rod, and the support rod is parallel to the end face of the pressure vessel head. This ensures that no matter what the posture of the pressure vessel head is, the rotation scanning direction of the distance detecting device is always the end face of the pressure vessel head, so that the accurate roundness of the pressure vessel head can be accurately obtained without being affected by the posture of the support rod and the pressure vessel head.

[0033] Therefore, under the solution of the present invention, there is no need to measure the absolute posture of the pressure vessel head, which solves the problem and defect that the pressure vessel head needs to be measured when it is placed arbitrarily.

[0034] The present invention includes a pressure vessel head roundness measurement method and a roundness measurement device. The pressure vessel head roundness measurement method uses a roundness measurement device to rotate and scan along the head end face at small angles, and sequentially obtains the distance between the distance detection device in the roundness measurement device and the corresponding detection point on the head inner wall when rotating to each small angle, as well as the accumulated center angle between the reference point, rotates and scans for one circle, selects the distances of four specific detection points to obtain the center position of the head end face, converts the distance between the distance detection device in the roundness measurement device and each detection point on the head inner wall into the distance between each detection point on the head inner wall and the center of the head end face, thereby realizing roundness measurement.

[0035] The pressure vessel head roundness measuring device comprises a support rod, a cushion block and a distance scanning detection component. The distance scanning detection component comprises a rotating device and a distance detection device. The rotating device in the distance scanning detection component is mounted on the support rod, and the distance detection device is mounted on the rotating device.

[0036] The present invention has the following beneficial effects:

[0037] 1) When the roundness of the pressure vessel head is detected, the roundness can be detected by simply placing the detection device on the end surface of the head at will, without positioning requirements, simple and convenient to use, and high detection efficiency; no complicated equipment installation is required, and the accuracy is ensured while eliminating the errors caused thereby;

[0038] 2) The pressure vessel head roundness measurement method and device are suitable for detecting the roundness of the end faces of pressure vessel heads with different diameters and different straight edge heights. It can also be used for roundness detection of objects that are similar to circles and have flat end faces, and has a wide range of applications.

[0039] In summary, the measuring method and device of the present invention have no positioning requirements in the head and are non-contact measurements, eliminating the need for positioning and contact measurements for traditional pressure vessel head roundness detection. The operation is very simple and convenient, and the detection efficiency is high. It also avoids errors caused by positioning and contact, and has higher accuracy and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a top view schematic diagram of a pressure vessel head roundness measuring device of the present invention.

[0041] Figure 2 It is a schematic side view of a pressure vessel head roundness measuring device of the present invention.

[0042] Figure 3 It is a schematic diagram of the composition of the distance scanning detection component of the present invention.

[0043] Figure 4 It is a schematic diagram of determining the center of the end face of a pressure vessel in the method for measuring the roundness of the end face of the pressure vessel of the present invention.

[0044] Figure 5 It is a schematic diagram of determining the end face roundness in the pressure vessel head roundness measurement method of the present invention.

[0045] In the figure: 1. Head; 2. Spacer block; 3. Support rod; 4. Distance scanning detection component; 5. Rotating device; 6. Distance detection device. DETAILED DESCRIPTION

[0046] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0047] like Figure 1 and Figure 2 As shown, the pressure vessel head roundness measuring device includes a support rod 3, a cushion block 2 and a distance scanning detection component 4; the head 1 is opened upward, and the two ends of the support rod 3 are supported by equal-height cushion blocks 2 and placed on both sides of the end surface of the head 1 of the pressure vessel, and a rotatable distance scanning detection component 4 is installed at the bottom of the support rod 3, so that the distance scanning detection component 4 is located in the space corresponding to the head 1.

[0048] The support rod 3 in the pressure vessel head roundness measuring device can be placed arbitrarily on the end face of the head 1, and can be arranged in a line at least on two locations of the end face of the head 1, without any positioning requirements.

[0049] The bottom surface of each end of the support rod 3 is placed on a cushion block 2 of equal height, and the cushion block 2 is placed on the edge end surface of the head 1.

[0050] like Figure 3As shown, the distance scanning detection component 4 is mainly composed of a distance detection device 6 and a rotating device 5. The distance detection device 6 in the distance scanning detection component 4 is installed on the support rod 3 through the rotating device 5, specifically installed on the bottom surface of the support rod 3. One end of the rotating device 5 is connected to the support rod 3, and the other end is connected to the distance detection device 6.

[0051] The rotation axis of the rotating device 5 is perpendicular to the mounting surface of the support rod 3, ie, the bottom surface, and is also perpendicular to the optical axis of the distance detection device 6, and the two axes intersect at one point.

[0052] The rotation scanning direction of the distance detection device 6 is parallel to the bottom surface of the support rod 3. The bottom surface of the support rod 3 is parallel to the end surface of the pressure vessel head through the equal height pad 2, and then parallel to the end surface of the pressure vessel head.

[0053] The distance detection device 6 may be a laser distance measuring device, or a similar device or sensor capable of detecting distance.

[0054] The measurement process of the present invention is as follows:

[0055] 1) Place the head roundness measuring device at any position on the end surface of the head 1 through the equal height pad 2; adjust the height of the pad 2 so that when the distance scanning detection component 4 rotates and scans along the end surface of the head 1, the scanned detection point is within the straight edge area of ​​the head.

[0056] 2) The distance scanning detection component 4 is used to rotate and scan one circle along the circumference of the end face of the end cap 1 from the initial position. Specifically, the distance between the distance detection device 6 of the distance scanning detection component 4 and the corresponding detection point on the inner wall surface of the end cap 1 is obtained at multiple locations of the angle rotation scanning one circle; and the cumulative center angle value between the distance detection device 6 of the distance scanning detection component 4 and the detection point corresponding to the initial position;

[0057] The distance detection device 6 of the distance scanning detection assembly 4 can detect in a straight line a point on the inner wall surface of the end cap 1 as a detection point.

[0058] 3) Select the detection point from the initial position of the distance detection device 6 of the distance scanning detection component 4 to the inner wall surface of the head 1 as the reference point, and select from the multiple distances obtained in step 2) the four distance values ​​O'A, O'B, O'A', O'B' between the distance detection device 6 of the distance scanning detection component 4 and the corresponding detection points on the inner wall surface of the head 1 when the cumulative center angle values ​​between the reference points are 0°, 90°, 180°, and 270° respectively; the center of the circle is the rotation center of the distance detection device 6 of the distance scanning detection component 4.

[0059] 4) According to the four distance values ​​obtained in step 3), determine the center position of the end face of the end cap 1;

[0060] like Figure 4As shown, the angle θ between the direction from the center O of the end face of the end cap 1 to the reference point O' measured by the distance detection device 6 and the direction O'A and the distance l from the center O of the end face of the end cap 1 to the reference point O' measured by the distance detection device 6 are determined specifically according to the following formulas:

[0061]

[0062] Among them, point O' is the reference point when the distance detection device 6 is measuring, points A, B, A', and B' are respectively four detection points on the inner wall of the head along the end face direction of the pressure vessel head when the distance detection device 6 rotates 90° clockwise or counterclockwise; point A is the corresponding detection point on the inner wall of the pressure vessel head when the distance detection device 6 is in the initial position or the rotating device 5 is in the initial position.

[0063] Then, the center position of the end face of the head 1 is determined in real time according to the angle θ and the distance l.

[0064] 5) According to the multiple distances obtained in step 2) and the accumulated center angle values ​​between the corresponding reference points, the distance between the detection point of each distance and the center of the circle obtained in step 4) is obtained by processing;

[0065] like Figure 5 As shown, the distance r between any detection point C and the center point O of the end face of the head 6 is obtained according to the following formula as the radius r at the detection point:

[0066] r=[m 2 +l 2 -2mlcos(ω-θ)] 1 / 2

[0067] In the formula, m is the detection distance from the reference point O' to the detection point C measured by the distance detection device 6 of the distance scanning detection component 4, l is the distance from the reference point O' to the end face center O measured by the distance detection device 6 of the distance scanning detection component 4, θ is the angle between the direction from the reference point O' to the end face center O measured by the distance detection device 6 of the distance scanning detection component 4 and the direction O'A, and ω is the cumulative angle when the distance detection device 6 of the distance scanning detection component 4 rotates from the reference point O' to the detection point C.

[0068] Based on this, the radius r corresponding to the distance detection device 6 rotating to each detection point at every small angle can be obtained. 1 ,r 2 ,···r n , thus obtaining the maximum radius r max =max(r 1 ,r 2 ,···r n ), minimum radius r min =min(r 1 ,r2 ,···r n ).

[0069] 6) The roundness of the end face of the end cap 1 is determined based on the distance between the detection points at various distances and the center of the circle obtained in step 4).

[0070] According to the maximum radius r max =max(r 1 ,r 2 ,···r n ) and the minimum radius r min =min(r 1 ,r 2 ,×··r n ) to obtain the roundness processing calculation as:

[0071] δ=(r max -r min ) / r ave

[0072] In the formula, r max r is the maximum radius of each detection point during a rotation scan of the distance scanning detection component 4 along the end surface of the head 1, min is the minimum radius of each detection point, r ave is the average radius of each detection point.

Claims

1. A method for measuring the roundness of a pressure vessel head, characterized in that: The steps are as follows: 1) using a distance scanning detection component (4) to rotate and scan along the circumference of the end face of the end cap (1) from an initial position for one circle, and obtaining the distance between the distance scanning detection component (4) and the corresponding detection point on the inner wall surface of the end cap (1) at multiple locations during the rotation and scanning of one circle; 2) selecting a detection point scanned by the distance scanning detection component (4) as a reference point, and selecting four distance values ​​O'A, O'B, O'A', O'B' between the distance scanning detection component (4) and the corresponding detection point on the inner wall surface of the head (1) when the cumulative center angle values ​​between the reference points are 0°, 90°, 180°, and 270° respectively from the multiple distances obtained in step 1); 3) determining the center position of the end face of the end cap (1) according to the four distance values ​​obtained in step 2); In the step 3), the angle θ between the direction from the center O of the end face of the end cap (1) to the reference point O' measured by the distance detection device (6) and the direction O'A and the distance l from the center O of the end face of the end cap (1) to the reference point O' measured by the distance detection device (6) are determined according to the following formula: Wherein, point O' is the reference point when the distance detection device (6) is measuring, and points A, B, A', and B' are four detection points on the inner wall of the head along the end face direction of the pressure vessel head when the distance detection device (6) rotates 90° in a clockwise or counterclockwise direction. Then, the center position of the end face of the head (1) is determined according to the angle θ and the distance l; 4) processing the distances between the detection points of each distance and the center of the circle obtained in step 3) according to the multiple distances obtained in step 1) and the accumulated center angle values ​​converted to the reference points; In step 4), the distance r between any detection point C and the center point O of the end face of the end cap (6) is obtained according to the following formula as the radius r at the detection point: r=[m 2 +l 2 -2mlcos(ω-θ)] 1 / 2 Wherein, m is the detection distance from the reference point O' to the detection point C measured by the distance scanning detection component (4), l is the distance from the reference point O' to the end face center O measured by the distance scanning detection component (4), θ is the angle between the direction from the reference point O' to the end face center O measured by the distance scanning detection component (4) and the direction O'A, and ω is the cumulative angle when the distance scanning detection component (4) rotates from the reference point O' to the detection point C; 5) Determine the roundness of the end face of the end cap (1) based on the distance between the detection points at various distances and the center of the circle obtained in step 3); The roundness of step 5) is calculated as: δ=(r max -r min ) / r ave In the formula, r max r is the maximum radius of each detection point during a rotation scan of the distance scanning detection component (4) along the end surface of the head (1), min is the minimum radius of each detection point, r ave is the average radius of each detection point.

2. The method for measuring roundness of a pressure vessel head according to claim 1, characterized in that: By adjusting the different heights of the cushion block (2), when the distance scanning detection component (4) rotates and scans along the end surface of the end cap (1), the detection point corresponding to the inner wall surface of the end cap (1) is located within the straight edge area of ​​the end cap.

3. The method for measuring roundness of a pressure vessel head according to claim 1, characterized in that: In the step 2), a point from the initial position of the scanning detection component (4) to the inner wall surface of the end cap (1) is selected as a reference point.

Images