A traceable industrial ct forest ball calibrator device

Abstract

The present application relates to the technical fields of industrial CT measuring machine, especially to a traceable industrial CT forest ball calibrator device, comprising a base and measuring needles, the measuring needles in the device have high rigidity, when the calibrator device is traced by using a coordinate measuring machine, contact measurement is needed for each standard ball of the measuring needles to obtain the spatial coordinates of each standard ball of the calibrator device, the high rigidity of the measuring needles can reduce the deflection change of the measuring needles in the measurement process, which can be ignored compared with the test accuracy, and the reliability and repeatability of the traceability are ensured, and the projection of the standard ball of the first layer of step measuring needles in the front view direction does not overlap with the projection of the third layer of step measuring needle support seats in the same direction; the first layer and the second layer of steps have 8 and 4 threaded holes respectively, the threaded hole positions are staggered by 30°, so as to reduce the stacking number of the calibrator device in the front view direction projection, the rays attenuate on the path, and the beam hardening is reduced.

Description

Technical Field

[0001] This invention relates to the field of industrial CT measuring machine technology, specifically to a traceable industrial CT forest ball calibrator device. Background Technology

[0002] The calibration devices used for calibrating industrial CT measuring machines are mostly ball plates or ball rods. Both types of calibration devices are used to test the measurement capabilities of industrial CT measuring machines in a two-dimensional plane. The forest ball calibration device, with its spatially distributed forest balls, can verify the measurement capabilities of industrial CT measuring machines in a three-dimensional plane. Common forest ball calibration devices are mainly divided into two types: one is made of a metal rod with a high density, which can lead to beam hardening during CT scanning, reducing the testing accuracy of the industrial CT measuring machine; the other is made of a carbon fiber rod with a lower density, significantly different from that of a ruby ​​ball, which can avoid beam hardening during CT scanning and provide better image contrast. However, the rigidity of a long carbon fiber rod decreases, making it impossible to assign values ​​using a high-precision coordinate measuring machine. Therefore, it is necessary to improve the structure of the forest ball calibration device to maintain sufficient rigidity of the probe while avoiding beam hardening that affects the CT scan results.

[0003] In summary, this invention addresses the existing problems by designing a traceable industrial CT forest ball calibrator device. Summary of the Invention

[0004] The purpose of this invention is to provide a traceable industrial CT forest ball calibrator device to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A traceable industrial CT forest ball calibrator device includes a base and a probe. The probe consists of a support rod, a carbon fiber rod, and a standard ball. The base is a three-layer cylindrical platform. The first and second steps of the base have 8 and 4 steps, respectively, for mounting the support rod. The third step has a threaded hole for mounting the support rod. The threaded holes on the first and second steps are offset by 30° from each other. The bottom of the carbon fiber rod is connected to the end face of the support rod, and the end face of the carbon fiber rod is equipped with a standard ball.

[0007] As a preferred embodiment of the present invention, the base is made of 4J36 Invar steel.

[0008] As a preferred embodiment of the present invention, the support rod is made of 4J36 Invar steel, and the bottom of the rod has external threads that mate with the threaded hole of the base.

[0009] As a preferred embodiment of the present invention, the top of the support rod is flat and mates with the carbon fiber rod, and there is a radial through hole in the middle for fastening the threaded pair of the support rod.

[0010] As a preferred embodiment of the present invention, the bottom of the carbon fiber rod is flat and is attached to the support rod by an adhesive, and the top is a blind hole for installing a standard ball.

[0011] As a preferred embodiment of the present invention, the standard ball is a complete sphere, which is bonded to a carbon fiber rod by an adhesive.

[0012] As a preferred embodiment of the present invention, the carbon fiber rod is made of carbon fiber, and the standard ball is made of ruby ​​ball.

[0013] As a preferred embodiment of the present invention, the diameter of the carbon fiber rod is the same as the diameter of the top of the support rod, both of which are larger than the diameter of a standard ball.

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] 1. In this invention, a traceable industrial CT forest ball calibration device is designed to ensure traceability. The probes in the calibration device have high rigidity. When tracing the calibration device using a coordinate measuring machine, it is necessary to perform contact measurements on the standard balls of each probe to obtain the spatial coordinates of each standard ball in the calibration device. The high rigidity of the probes can reduce the deflection of the probes, which is negligible compared with the test accuracy, ensuring the reliability and repeatability of traceability. In addition, the projection of the standard ball of the first-layer step probe in the main view direction and the projection of the third-layer step probe support in the same direction do not overlap. The first and second layers of the base are respectively provided with 8 and 4 threaded holes, and the positions of the threaded holes are staggered by 30° to reduce the number of stacked projections of the calibration device in the main view direction, thereby reducing the attenuation of the rays on the path, reducing beam hardening, and improving measurement accuracy. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the base structure of the present invention;

[0017] Figure 2 For the present invention Figure 1 Partial structural diagram;

[0018] Figure 3 For the present invention Figure 2 Partial structural diagram;

[0019] Figure 4 This is a schematic diagram of the probe structure of the present invention.

[0020] In the diagram: 1. Base; 2. Probe; 201. Support rod; 202. Carbon fiber rod; 203. Standard ball. Detailed Implementation

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0022] To facilitate understanding of the present invention, a more comprehensive description of the invention will be given below with reference to the accompanying drawings, and several embodiments of the invention will be provided. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of the present invention will be more thorough and complete.

[0023] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0025] For examples, please refer to Figure 1-4 The present invention provides a technical solution:

[0026] A traceable industrial CT forest ball calibration device includes a base 1 and a probe 2. The probe 2 is composed of a support rod 201, a carbon fiber rod 202, and a standard ball 203.

[0027] The base 1 is made of 4J36 Invar steel, which has a small coefficient of thermal expansion, reducing the impact of temperature changes on morphology and dimensions. The base has three steps. It should be ensured that the projection of the standard ball 203 of the probe 2 on the first step in the main view direction does not overlap with the projection of the support rod 201 of the probe 2 on the third step in the same direction. This is to reduce the attenuation of the ray as it passes through the standard ball, reduce beam hardening, and improve measurement accuracy. The first and second steps of the base 1 are provided with 8 and 4 threaded holes, respectively, with the threaded holes offset by 30° to reduce the number of stacked calibration devices projected in the main view direction.

[0028] The support rod 201 is made of 4J36 Invar steel, which has a small coefficient of expansion, reducing the influence of temperature changes on its shape and size. The bottom of the support rod 201 is externally threaded and has a threaded fit with the base 1. The top of the support rod 201 is an end face and has a face fit with the carbon fiber rod 202. The middle part of the support rod 201 contains a through hole through the shaft, and the threaded pair is tightened with a wrench.

[0029] The carbon fiber rod 202, made of carbon fiber, possesses high rigidity and low density. Its high rigidity ensures that the stylus deflection is negligible when assigning values ​​to the calibration device using a coordinate measuring machine. The low-density material reduces attenuation along the X-ray path during CT scans, improving image quality. The bottom of the carbon fiber rod 202 is an end face that mates with the support rod 201, and is fixed to the top of the support rod 201 using adhesive. The top of the carbon fiber rod 202 is an end face combined with a blind hole located at the center of the end face. A standard ball 203 is fixed to it using adhesive, eliminating the need for machining the standard ball 203 and ensuring its sphericity stability. The diameter of the carbon fiber rod 202 should be the same as the top diameter of the support rod 201, both larger than the diameter of the standard ball 203, to ensure good overall rigidity of the stylus 2. Contact measurement using a coordinate measuring machine ensures negligible deflection of the stylus, resulting in accurate and repeatable measurement results.

[0030] The standard sphere 203 is made of ruby ​​spheres. Ruby spheres have mature processing technology, good thermal stability, moderate X-ray attenuation coefficient, and high imaging contrast, making them very suitable as calibration equipment for industrial CT.

[0031] Workflow of this invention:

[0032] (1) Use industrial CT to scan the forest ball to obtain the three-dimensional model of the calibrator, and calculate the center distance A0 of 35 groups of ruby ​​balls;

[0033] (2) Use a three-coordinate measuring instrument to measure the spatial coordinates of each ruby ​​ball, and then obtain the center point of the ruby ​​ball, B0.

[0034] (3) Using B0 as the standard value and A0 as the test value, the difference between the two can be used to obtain the indication error of the CT equipment.

[0035] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A traceable industrial CT forest ball calibrator device, comprising a base (1) and a probe (2), characterized in that, The probe (2) consists of a support rod (201), a carbon fiber rod (202), and a standard ball (203). The base (1) is a three-layer cylindrical platform. The first and second steps of the base (1) have 8 and 4 threaded holes respectively for installing the support rod (201), and the third step has 1 threaded hole for installing the support rod (201). The threaded holes on the first and second steps are offset by 30° from each other. The bottom of the carbon fiber rod (202) is connected to the end face of the support rod (201). A standard ball (203) is installed on the end face of the carbon fiber rod (202); the support rod (201) is made of 4J36 Invar steel, and the bottom of the rod is externally threaded, which is matched with the threaded hole of the base (1); the top of the support rod (201) is flat and matches the carbon fiber rod (202), and there is a radial through hole in the middle for fastening the threaded pair of the support rod (201); the bottom of the carbon fiber rod (202) is flat and matches the support rod (201) with adhesive, and the top is a blind hole for installing the standard ball (203).

2. The traceable industrial CT forest ball calibrator device according to claim 1, characterized in that: The base (1) is made of 4J36 Invar steel.

3. The traceable industrial CT forest ball calibrator device according to claim 1, characterized in that: The standard ball (203) is a complete sphere, which is bonded to the carbon fiber rod (202) with an adhesive.

4. The traceable industrial CT forest ball calibrator device according to claim 3, characterized in that: The carbon fiber rod (202) is made of carbon fiber, and the standard ball (203) is made of ruby.

5. The traceable industrial CT forest ball calibrator device according to claim 4, characterized in that: The diameter of the carbon fiber rod (202) is the same as the diameter of the top of the support rod (201), both of which are larger than the diameter of the standard ball (203).

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