Method for checking straightness detection precision of detection equipment

Abstract

The invention discloses a detection equipment straightness detection precision verification method, which comprises the following steps: 1) detection data acquisition: detecting two finish machining working surfaces of a straightness standard device by using detection equipment to carry out n times of straightness detection to obtain n groups of straightness data; 2) detection data analysis: performing MSA analysis on the obtained n groups of straightness data to obtain Cg and Cgk values; and 3) generating a detection result: if the Cg value is greater than 1.33 and the Cgk value is greater than 1.33, determining that the straightness detection precision of the detection equipment is verified to be qualified. According to the method for verifying the straightness detection precision of the detection equipment, the adopted straightness standard device is high in rigidity, small in deformation, good in stability and further high in precision, correspondingly, the precision of the finish machining working faces is high, the two finish machining working faces of the straightness standard device only need to be measured once during each straightness detection during verification, the verification process is simplified, and the verification efficiency is improved. And the verification efficiency and the detection precision are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of precision measurement, and in particular relates to a method for calibrating the straightness detection accuracy of a detection device. Background Art

[0002] As a precision measuring instrument, the three-dimensional coordinate measuring machine is one of the earliest intelligent detection equipment developed in the industrial field. It has high measurement accuracy and strong anti-interference ability. It is widely used in the manufacturing industry to measure and inspect parameters such as part size and behavioral tolerance.

[0003] As a key device for precision measurement in the manufacturing industry, the measurement accuracy of the three-dimensional coordinate measuring machine is directly related to product quality and production efficiency. In order to ensure the long-term stable and reliable operation of the three-dimensional coordinate measuring machine, it is necessary to calibrate and maintain it regularly to ensure the measurement accuracy and stability of the three-dimensional coordinate measuring machine and meet the strict requirements of the manufacturing industry for product quality inspection.

[0004] In the calibration process of the three-dimensional coordinate measuring machine, the straightness standard is one of the commonly used calibration objects. Straightness reflects the linear accuracy of the motion of each coordinate axis of the three-dimensional coordinate measuring machine and is an important indicator for evaluating the geometric accuracy of the machine.

[0005] The straightness calibration of the three-dimensional coordinate measuring machine usually uses a straightness standard. Traditional straightness standards usually include a long rectangular standard body and a support. The standard body is made of alumina ceramics, which has poor rigidity and stability, resulting in low machining accuracy, poor rigidity, and general stability of the calibrator body. During calibration, the top working surface (which measures the vertical component of straightness) of the two mutually perpendicular working surfaces of the standard body needs to be measured twice in the forward and reverse directions, and the side working surface (which measures the horizontal component of straightness) needs to be measured in the forward and reverse directions to improve the calibration accuracy. Therefore, it is necessary to rotate the standard body 180° so that the top working surface faces upward for forward measurement and then faces downward for reverse measurement, and the side working surface faces right (or left) for forward measurement and then faces left (or right) for reverse measurement. Therefore, a rotating mechanism must be set on the support to realize the rotation of the standard body, and both the top working surface and the side working surface need to be measured in both forward and reverse directions. The deviation value is calculated by a specific algorithm based on the measured values ​​in both forward and reverse directions, which results in a complicated straightness calibration process of the three-dimensional coordinate measuring machine, low calibration efficiency, and large cumulative errors. Summary of the invention

[0006] The invention provides a method for calibrating the straightness detection accuracy of a detection device, which has a simple calibration process, high efficiency and high accuracy.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is a method for calibrating the straightness detection accuracy of a detection device, comprising the following steps: 1) Detection data acquisition: configure a straightness standard, the straightness standard includes a standard body, a first support and a second support, the standard body is horizontally arranged and is a rectangular strip made of silicon carbide ceramic, the top surface of which is a fine-machined working surface, and one of the left and right side surfaces is a fine-machined working surface; the first support and the second support are located below the standard body, and are respectively supported at two Airy point positions of the standard body; The detection device is used to detect the two fine-machined working surfaces of the straightness standard for n straightness detections to obtain n sets of straightness data; wherein each straightness detection includes one detection of one of the fine-machined working surfaces and one detection of the other fine-machined working surface; 2) Test data analysis: Perform MSA analysis on the n sets of straightness data obtained to obtain Cg and Cgk values; the measuring tool repeatability coefficient Cg=20%T / 4Sg; the measuring tool accuracy coefficient Cgk=(10%T-|Bi|) / 2Sg; in: T: measurement value tolerance zone; Bi: average value of measured value - nominal value of measured value; Sg: standard deviation of the measured values; 3) Generate test results: If the Cg value is greater than 1.33 and the Cgk value is greater than 1.33, the straightness test accuracy of the test equipment is verified to be qualified.

[0008] The technical solution of the present invention also includes the following additional technical features: The first support comprises a first support body and a first support member fixed on the horizontal top surface of the first support body, and a ball socket is formed on the first support member; The second support comprises a second support body and a second support member fixed on the horizontal top surface of the second support body, wherein the second support member has a horizontal support top surface; A first ball head is provided on the bottom surface of the standard body at the Airy point position corresponding to the first support, and the first ball head is fitted in the ball socket; Two second ball heads are provided on the bottom surface of the standard body at the Airy point position corresponding to the second support, and the second ball heads are supported on the horizontal supporting top surface of the second supporting member.

[0009] In a direction parallel to the length direction of the standard body, the installation position of the first support member on the horizontal top surface of the first support is adjustable, and the installation position of the second support member on the horizontal top surface of the second support is adjustable.

[0010] The straightness standard also includes: The support platform has a horizontal top surface, and the first support and the second support are installed on the horizontal top surface of the support platform.

[0011] In a direction parallel to the length direction of the standard device body, the installation positions of the first support and the second support on the horizontal top surface of the support platform are adjustable.

[0012] The standard device body is a hollow structure with two ends penetrating through.

[0013] The bottom surface and the other of the left and right side surfaces of the standard body are non-finished surfaces, and marks are arranged on the non-finished surfaces.

[0014] Compared with the prior art, the present invention has the following advantages and positive effects: The present invention discloses a method for calibrating the straightness detection accuracy of detection equipment. A straightness standard device used in detection data collection includes a standard device body and a first support and a second support supported at two Elvey point positions of the standard device body. The standard device body is made of silicon carbide ceramic. Silicon carbide ceramic is a high-rigidity material made of silicon carbide through sintering technology. The material has zero gaps, high rigidity, small deformation, and little influence of ambient temperature and humidity on its stability. Therefore, the standard device body has high rigidity, small deformation, good stability, and thus high precision. Correspondingly, the precision of the fine-machined working surface is high. During calibration, each straightness detection only requires measuring the two fine-machined working surfaces of the linear standard device once, which simplifies the calibration process and improves calibration efficiency and detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0016] Figure 1 is a stereoscopic diagram of a straightness standard used in an embodiment of the present invention; Figure 2 for Figure 1 A top view of Figure 3 for Figure 2 The AA section view is an enlarged view after being rotated 90° counterclockwise; Figure 4 for Figure 2 The enlarged view of the BB section view after rotating 90° clockwise; Figure 5 It is a three-dimensional diagram of the assembly structure of the first support, the second support and the support platform in an embodiment of the present invention; Figure 6 for Figure 5 Enlarged view of part C.

[0017] Reference numerals: 10. Standard instrument body; 11. Top surface; 12. Right side surface; 13. Bottom surface; 14. Left side surface; 15. First ball head; 16. Second ball head; 17. Raised mark; 20. first support; 21. first support body; 22. first support member; 23. ball socket; 24. first screw hole; 25. first mounting hole; 30. Second support; 31. Second support body; 32. Second support member; 33. Horizontal support top surface; 34. Second mounting hole; 40. Support table. DETAILED DESCRIPTION

[0018] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0019] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0020] Reference Figure 1 In some embodiments of the present invention, a method for calibrating the straightness detection accuracy of a detection device is provided, comprising the following steps: 1) Test data collection: Configure a straightness standard, which includes a standard body 10, a first support 20 and a second support 30; the standard body 10 is horizontally arranged, and is in the shape of a rectangular strip, and is made of silicon carbide ceramic. Among the four side surfaces of the circumferential side surface of the standard body 10, the two opposite side surfaces are parallel and symmetrical to each other, and the two adjacent surfaces are perpendicular to each other, wherein the top surface 11 is a finely machined working surface, and one of the left and right side surfaces is also a finely machined working surface, such as Figure 1As shown, the top surface 11 and the right side surface 12 of the standard body 10 are finely machined working surfaces; the first support 20 and the second support 30 are located below the standard body 10, and are spaced apart along the length direction of the standard body 10 to jointly support the standard body 10. The first support 20 and the second support 30 are respectively located at two Elvey points of the standard body 10. The Elvey point is a position on the rod-shaped member that is 0.211L (L is the length of the rod-shaped member) away from its two end faces. Supporting at the Elvey point position can keep the two end faces of a horizontally placed object parallel under the action of gravity; The detection device is used to detect two fine-machined working surfaces (top surface 11 and right side surface 12) of the straightness standard for n straightness detections to obtain n sets of straightness data, where n is a positive integer; wherein each straightness detection includes one detection of one fine-machined working surface and one detection of the other fine-machined working surface; 2) Test data analysis: Perform MSA analysis on the n sets of straightness data obtained, that is, measurement system analysis, to obtain Cg and Cgk values; the measuring tool repeatability coefficient Cg=20%T / 4Sg; the measuring tool accuracy coefficient Cgk=(10%T-|Bi|) / 2Sg; in: T: measurement value tolerance zone; Bi: average value of measured value - nominal value of measured value; Sg: standard deviation of the measured values; T, Bi, and Sg are directly obtained from each set of straightness data.

[0021] 3) Generate test results: If the Cg value is greater than 1.33 and the Cgk value is greater than 1.33, the straightness test accuracy of the test equipment is verified to be qualified.

[0022] Specifically, the Cg value is greater than 1.33, which means that the discrete range of the measurement value of the detection equipment is very narrow relative to the tolerance range, and the repeatability capability of the measuring tool meets the requirements; the Cgk value is greater than 1.33, which means that the detection equipment is accurate and has high repeatability.

[0023] If the above formula is used to verify that it is qualified, it can be explained that the straightness detection accuracy of the detection equipment meets the straightness detection of the workpiece with an accuracy close to that of the above straightness standard.

[0024] The straightness standard used in the straightness detection accuracy calibration method of the detection equipment in this embodiment has a standard body 10 made of silicon carbide ceramic. Silicon carbide ceramic is a high-rigidity material made of silicon carbide through sintering technology. This material has zero gaps, high rigidity, small deformation, and little influence of ambient temperature and humidity on its stability, that is, good stability. Therefore, the standard body 10 has high rigidity, small deformation, good stability, and high accuracy. Correspondingly, the precision of the fine-machined working surface is high. When used for calibration of detection equipment such as a three-coordinate measuring machine or other straightness inspection tools, it is only necessary to measure each of the two fine-machined working surfaces of the standard body 10, thereby simplifying the calibration process and improving the calibration efficiency.

[0025] And since it is only necessary to measure each of the two finely machined working surfaces of the standard body 10 once, the straightness standard does not need to be provided with a rotating mechanism to realize the rotation of the standard body 10 as in the prior art, which greatly simplifies the structure of the standard, reduces the production cost, and further reduces the cost of straightness accuracy calibration of the detection equipment.

[0026] When the standard body 10 is processed, a high-resolution optical collimator is used to perform real-time detection in a constant temperature and humidity environment, and repeated grinding is performed according to the detection results until the required ultra-high precision is met.

[0027] In some embodiments of the present invention, in step 1), the value of n is 50, or the number of detection times is reasonably adjusted according to specific verification and detection conditions, and no specific limitation is made here.

[0028] In some embodiments of the present invention, reference Figures 2 to 6 , while combining Figure 1 The first support 20 includes a first support body 21 and a first support member 22 fixed on the horizontal top surface 11 of the first support body 21 , and a ball socket portion 23 is formed on the first support member 22 .

[0029] The second support 30 includes a second support body 31 and a second support member 32 fixed on the horizontal top surface 11 of the second support body 31 . The second support member 32 has a horizontal support top surface 33 .

[0030] A first ball head 15 is provided on the bottom surface 13 of the standard body 10 at the Airy point position corresponding to the first support 20, and the first ball head 15 is fitted in the ball socket 23; two second ball heads 16 are provided on the bottom surface 13 of the standard body 10 at the Airy point position corresponding to the second support 30, and the second ball heads 16 are supported on the horizontal support top surface 33 of the second support member 32.

[0031] The standard body 10 and the first support 20 are positioned by a ball head and a ball socket at one Elvey point, and the other Elvey point and the second support 30 are positioned by two ball heads and a horizontal plane. Under the premise of achieving three-point reliable support, compared with the fixed fulcrum support, it has a certain expansion space, which can reduce the linear expansion of the standard body 10 caused by temperature increase and other reasons, and avoid deformation such as warping at both ends or bulging in the center due to the fixing of the two ends.

[0032] During the fine grinding, precision testing and use stages, the standard body 10 is supported by the above-mentioned three-point support to keep the standard body 10 in the same posture during use and processing, ensuring that the deformation is minimized.

[0033] In some embodiments of the present invention, in a direction parallel to the length direction of the standard body 10, the installation position of the first support member 22 on the horizontal top surface of the first support 20 is adjustable, and the installation position of the second support member 32 on the horizontal top surface of the second support 30 is adjustable, so that the installation positions of the first support member 22 and the second support member 32 can be changed according to the standard body 10 of different lengths, thereby improving versatility.

[0034] Specifically, the first support member 22 is fastened and installed on the horizontal top surface of the first support 20 by screws, and the second support member 32 is also fastened and installed on the horizontal top surface of the second support 30 by screws. A plurality of first screw holes 24 arranged at intervals in a direction parallel to the length direction of the standard body 10 can be provided on the first support 20 and the second support 30 (the first screw holes on the second support 30 are blocked by the second support member 32, not shown in the figure), so that the first screw holes 24 at appropriate positions can be selected according to the standard body 10 of different lengths to install the first support member 22 and the second support member 32, so as to achieve adjustable installation position.

[0035] In some embodiments of the present invention, Figure 1 , Figure 2 and Figure 5 As shown, the straightness standard also includes a support table 40, which has a horizontal top surface. The first support 20 and the second support 30 are installed on the horizontal top surface of the support table 40, so that the first support 20, the second support 30 and the support table 40 form a whole, which is convenient for overall transportation and movement, and convenient for the whole to be placed on a three-dimensional coordinate measuring machine to be calibrated.

[0036] In some embodiments of the present invention, the installation positions of the first support 20 and the second support 30 on the horizontal top surface of the support platform 40 are adjustable in a direction parallel to the length direction of the standard body 10, so that the installation positions of the first support 20 and the second support 30 can be changed according to the different lengths of the standard body 10. By adjusting the positions of the first support 20 and the second support 30 and the first support member 22 and the second support member 32, the adjustment range can be expanded, thereby improving the convenience of adjustment.

[0037] Specifically, the first support 20 is fastened and installed on the horizontal top surface of the support platform 40 by screws, and the second support 30 is also fastened and installed on the horizontal top surface of the support platform 40 by screws. The first mounting hole 25 on the first support 20 is set as a long strip screw hole, and the second mounting hole 34 on the second support 30 is set as a long strip screw hole, and the length direction of the long strip screw hole is parallel to the length direction of the standard body 10, so that the first support 20 and the second support 30 can be fixed at a suitable position according to the standard body 10 of different lengths, so as to achieve adjustable installation position.

[0038] In some embodiments of the present invention, the standard body 10 is a hollow structure with two ends connected. On the premise of ensuring good rigidity of the silicon carbide ceramic standard body 10, lightweight is achieved to avoid deformation of the standard body 10 due to excessive weight as much as possible.

[0039] Since the bottom surface 13 of the standard body 10 and the other side surface (such as Figure 1 The left side surface 14 shown in the figure is a non-working surface, and the bottom surface 13 and the left side surface 14 of the standard body 10 can be set as non-finished surfaces to reduce the processing cost.

[0040] For easy identification, a mark can be set on the non-finished surface to indicate that this surface is a non-working surface to avoid misoperation. Figure 1 A raised mark 17 is provided on the left side surface 14 of the central standard body 10 , and the first ball head 15 and the second ball head 16 on the bottom surface 13 of the standard body 10 can also serve as marks of the bottom surface 13 .

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for calibrating the straightness detection accuracy of a detection device, characterized in that: The steps include: 1) Detection data acquisition: configure a straightness standard, the straightness standard includes a standard body, a first support and a second support, the standard body is horizontally arranged and is a rectangular strip made of silicon carbide ceramic, the top surface of which is a fine-machined working surface, and one of the left and right side surfaces is a fine-machined working surface; the first support and the second support are located below the standard body, and are respectively supported at two Airy point positions of the standard body; The detection device is used to detect the two fine-machined working surfaces of the straightness standard for n straightness detections to obtain n sets of straightness data; wherein each straightness detection includes one detection of one of the fine-machined working surfaces and one detection of the other fine-machined working surface; 2) Test data analysis: Perform MSA analysis on the n sets of straightness data obtained to obtain Cg and Cgk values; the measuring tool repeatability coefficient Cg=20%T / 4Sg; the measuring tool accuracy coefficient Cgk=(10%T-|Bi|) / 2Sg; in: T: measurement value tolerance zone; Bi: average value of measured value - nominal value of measured value; Sg: standard deviation of the measured values; 3) Generate test results: If the Cg value is greater than 1.33 and the Cgk value is greater than 1.33, the straightness test accuracy of the test equipment is verified to be qualified.

2. The method for calibrating the straightness detection accuracy of a detection device according to claim 1, characterized in that: The first support comprises a first support body and a first support member fixed on the horizontal top surface of the first support body, and a ball socket is formed on the first support member; The second support comprises a second support body and a second support member fixed on the horizontal top surface of the second support body, wherein the second support member has a horizontal support top surface; A first ball head is provided on the bottom surface of the standard body at the Airy point position corresponding to the first support, and the first ball head is fitted in the ball socket; Two second ball heads are provided on the bottom surface of the standard body at the Airy point position corresponding to the second support, and the second ball heads are supported on the horizontal supporting top surface of the second supporting member.

3. The method for calibrating the straightness detection accuracy of a detection device according to claim 2, characterized in that: In a direction parallel to the length direction of the standard body, the installation position of the first support member on the horizontal top surface of the first support is adjustable, and the installation position of the second support member on the horizontal top surface of the second support is adjustable.

4. The method for calibrating the straightness detection accuracy of a detection device according to claim 1, characterized in that: The straightness standard also includes: The support platform has a horizontal top surface, and the first support and the second support are installed on the horizontal top surface of the support platform.

5. The method for calibrating the straightness detection accuracy of a detection device according to claim 4, characterized in that: In a direction parallel to the length direction of the standard device body, the installation positions of the first support and the second support on the horizontal top surface of the support platform are adjustable.

6. The method for calibrating the straightness detection accuracy of a detection device according to claim 1, characterized in that: The standard device body is a hollow structure with two ends penetrating through.

7. The method for calibrating the straightness detection accuracy of a detection device according to claim 1, characterized in that: The bottom surface and the other of the left and right side surfaces of the standard body are non-finished surfaces, and marks are arranged on the non-finished surfaces.

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