In recent years, with the expansion of production scale and the continuous development of new processes, the complex process environment has placed higher and higher requirements on detection products. Endoscope inspection is an inspection technology that has gradually been widely used in recent years with the development of industrial endoscope manufacturing technology. Through the inspection of industrial endoscopes, workers can detect the size and size of defects in pressure vessels and pipeline welds. Defect characteristics can be accurately judged. Through regular inspection, staff can promptly discover whether there are new defects during use, so that staff can be promptly reminded to repair the equipment to achieve the purpose of ensuring the safety of equipment and personnel.
1. About industrial endoscopes
The endoscope is a multi-disciplinary tool. Its function is to explore the depths of curved pipes, observe parts that cannot be seen directly, observe the internal spatial structure and status in sealed cavities, and enable long-distance observation. and operations. If we want to explore the origin of endoscopy, which is "using a certain tool to observe the inside of the human body", it can be traced back to the ancient Greek and Roman times.
Industrial endoscopes are mainly used in automobiles, aerospace engines, pipelines, mechanical parts, etc. They can achieve non-destructive testing without disassembling or destroying the assembly or stopping the equipment. They are widely used in petrochemical, aviation, automobiles, ships, electrical , chemistry, electricity, gas, atomic energy, civil construction and other modern core industries.
China began to introduce endoscope products from abroad in the 1970s and 1980s, which were mainly used for internal excess control of aerospace products and quality inspection of some parts. There are many types of instruments, and industrial endoscopes are one of them. Domestic endoscope testing has entered a practical stage, is increasingly used in quality control of product production processes, and has developed into a conventional testing method.
2. Classification of industrial endoscopes
In terms of materials, endoscopes can be divided into two types: rigid tube type and flexible endoscope, also known as rigid endoscopes and flexible endoscopes.
1. Rigidity
The endoscope consists of three parts: image transmission, lighting, and stoma. The image transmission part is divided into objective lens, relay system and eyepiece to form the transmission image. The lighting part adopts the method of penetrating the cold light source into the interior with optical fiber. The function of the stomata is to supply air, water, and pass the biopsy forceps.
2. Softness
Endoscopes that use fiber beams to transmit images and guide light or use CCDs to transmit images are called flexible endoscopes. Because of its good softness and convenient operation performance, the characteristics of flexible endoscopes are: it can be easily entered and can reach places that rigid endoscopes cannot reach. Coupled with the head bending mechanism, blind spots can be eliminated. Samples and treatments can be taken through the biopsy hole. Flexible endoscopes can be divided into fiber endoscopes and electronic endoscopes.
In terms of imaging forms, it includes optical mirrors, fiber optic mirrors, and electronic mirrors.
1. Optical mirror
It completely transmits the internal object image to the eyes of the observer without distortion, so the image is very fidelity and has the highest clarity among these types of mirrors.
2. Fiber optic scope
The principle is similar to that of an optical mirror. In order to enter the smaller holes, we choose a fiber optic mirror. The clarity of the fiber optic mirror depends on the number of fiber bundles.
Fiber endoscope: the tip part, the bending part, the insertion part, the operating part, the light guide hose, the light guide connection part, and the tip part of the eyepiece are formed into a small rigid section, including direct view (front view), side view, and strabismus. Mode. Gastroscopy and colonoscopy use direct viewing, while duodenoesophagoscopy uses side viewing. There are: objective lens hole (image guide beam), optical hole (light guide beam), air and water hole (nozzle), and biopsy hole on the tip. The bending part uses four steel wire traction methods. The head has four steel wires connected to the control part. By twisting the up, down, left and right hand wheels of the control part, the steel wires in different directions can be pulled respectively, making the bending head swing in the corresponding direction. There are guide beams, guide image beams, various pipes, traction devices, bending tubes, and bending rubber in the bending part.
The hose part includes a bending part and an insertion part, also called a snake tube. It is equipped with a guide beam, an image guide beam, a water and gas pipe, a biopsy pipe (also a suction pipe), a traction wire, and is wrapped with a stainless steel hose and a metal mesh tube. The outer layer is a smooth plastic casing. The fiber bundle that transmits the image forms the core part of the fiber endoscope. It is composed of tens of thousands of extremely fine glass fibers. According to the principle of total optical reflection, all glass fibers must be covered with a film with a lower refractive index. Ensure that all light transmitted by the inner core fiber can undergo total reflection. The transmission of a single fiber can only produce a point of light. If you want to see an image, you must bundle a large number of fibers. If you want to transmit the image to the other end to form the same image, you must make each fiber in its direction. The two ends are arranged in the same position and are called guide beams. If one guide beam is disconnected, there will be one more black spot in the image. The light guides do not need to be arranged in the same position. If many of them are disconnected, the brightness will be significantly reduced.
3. Principles of Industrial Endoscope Detection
Industrial endoscopy is a branch of non-destructive testing, which can also be said to be a specialized testing technology. There are four methods: visual inspection (VT), radiographic inspection (RT), ultrasonic testing (UT), magnetic particle testing (MT) and liquid penetrant testing (PT). Other non-destructive testing methods: eddy current testing (ET), acoustic emission testing (AT), thermal imaging/infrared (TIR), leakage test (LT), alternating current field measurement technology (ACFMT), magnetic flux leakage testing (MFL), far-field testing Detection method (RFT), etc.
1. Detection range
Inspection of weld surface defects. Check the welding quality such as cracks, incomplete penetration and leakage on the weld surface.
Inner cavity inspection. Check for defects such as surface cracks, peeling, pull lines, scratches, pits, bulges, spots, corrosion, etc.
Status check. After certain products (such as worm gear pumps, engines, etc.) are put into operation, endoscopic inspection is carried out according to the items specified in the technical requirements.
Assembly inspection. When required and needed, use industrial video endoscopes to inspect assembly quality; after assembly or a certain process is completed, check whether the assembly position of each component meets the requirements of the drawing or technical conditions; whether there are assembly defects.
Check for excess. Check the inner cavity of the product for residual shavings, foreign objects and other excess matter.
Due to its special size design, industrial endoscopes allow us to easily and accurately observe the internal surface structure or working status of the object without damaging the surface of the object being inspected. Non-destructive testing requires the use of industrial endoscopes as inspection tools, which are professionally designed and produced to meet the complex industrial use environment. Endoscope inspection is a kind of inspection technology that has gradually been widely used with the development of endoscope production and manufacturing technology. According to the characteristics of the manufacturing process, we generally divide industrial endoscopes into three types: optical rigid endoscopes, fiber optic endoscopes, and video endoscopes.
Industrial endoscopes can be used for inspection and observation of high temperature, toxic, nuclear radiation and places that cannot be directly observed by the human eye. They are mainly used in automobiles, aerospace engines, pipelines, mechanical parts, etc., and can be used in assemblies and equipment without disassembly or damage. Non-destructive testing can be achieved when the operation is stopped. On the other hand, industrial endoscopes can also be connected to cameras, video cameras or computers to form photography, video and image processing systems to monitor, record, store and image field targets. Image analysis provides a good guarantee for diagnosis and treatment.
3. Principles of Industrial Endoscope Detection
Industrial endoscopy is a branch of non-destructive testing, which can also be said to be a specialized testing technology. There are four methods: visual inspection (VT), radiographic inspection (RT), ultrasonic testing (UT), magnetic particle testing (MT) and liquid penetrant testing (PT). Other non-destructive testing methods: eddy current testing (ET), acoustic emission testing (AT), thermal imaging/infrared (TIR), leakage test (LT), alternating current field measurement technology (ACFMT), magnetic flux leakage testing (MFL), far-field testing Detection method (RFT), etc.
1. Detection range
Inspection of weld surface defects. Check the welding quality such as cracks, incomplete penetration and leakage on the weld surface.
Inner cavity inspection. Check for defects such as surface cracks, peeling, pull lines, scratches, pits, bulges, spots, corrosion, etc.
Status check. After certain products (such as worm gear pumps, engines, etc.) are put into operation, endoscopic inspection is carried out according to the items specified in the technical requirements.
Assembly inspection. When required and needed, use industrial video endoscopes to inspect assembly quality; after assembly or a certain process is completed, check whether the assembly position of each component meets the requirements of the drawing or technical conditions; whether there are assembly defects.
Check for excess. Check the inner cavity of the product for residual shavings, foreign objects and other excess matter.
Due to its special size design, industrial endoscopes allow us to easily and accurately observe the internal surface structure or working status of the object without damaging the surface of the object being inspected. Non-destructive testing requires the use of industrial endoscopes as inspection tools, which are professionally designed and produced to meet the complex industrial use environment. Endoscope inspection is a kind of inspection technology that has gradually been widely used with the development of endoscope production and manufacturing technology. According to the characteristics of the manufacturing process, we generally divide industrial endoscopes into three types: optical rigid endoscopes, fiber optic endoscopes, and video endoscopes.
Industrial endoscopes can be used for inspection and observation of high temperature, toxic, nuclear radiation and places that cannot be directly observed by the human eye. They are mainly used in automobiles, aerospace engines, pipelines, mechanical parts, etc., and can be used in assemblies and equipment without disassembly or damage. Non-destructive testing can be achieved when the operation is stopped. On the other hand, industrial endoscopes can also be connected to cameras, video cameras or computers to form photography, video and image processing systems to monitor, record, store and image field targets. Image analysis provides a good guarantee for diagnosis and treatment.
4. Technical performance of industrial endoscopes
First of all, the auxiliary judgment of color is extremely critical. Accurate color reproduction is often important when identifying defects in corrosion, weld zone burn-through and chemical composition. The color reproduction of the industrial endoscope's screen imaging system is excellent. It can record each of the three primary colors with full broadband, thereby achieving maximum resolution. Second, automatic and intelligent adjustment of light source brightness is also a necessary condition for good observation results. For example, the internal surface of the mold cavity is generally made of metal material, which has a certain degree of reflectivity. If the brightness of the light source cannot be adjusted steplessly and automatically, but can only be adjusted by manual extension, the obtained observation effect will definitely produce strong reflective white spots, which may make it impossible to complete the observation work, thereby affecting the detection effect. The third is the all-round 360-degree guiding function, which is indispensable in actual work. When observing the interior of the container, we must not only observe the top, but also check the bottom, and pay attention to the surrounding conditions, which requires industrial The endoscope probe can rotate 360 degrees. If only four directions of guidance can be achieved, the axial rotation operation of the insertion tube will have to be cumbersome, which increases the difficulty of the work and affects the observation effect. Fourth, the guarantee of measurement accuracy certification will also make users full of information about the test results. This is just like how we feel when using a ruler with accuracy certification and a ruler without accuracy certification. The measurement work was indeed done, but without accuracy certification, the credibility of the data cannot be guaranteed.
As an efficient and accurate non-destructive testing tool, Shenzhen QBH industrial endoscope can provide solutions for various types of pipeline safety testing. Through timely discovery and treatment of internal defects in pipelines, the safety and stability of pipelines can be ensured, and production risks and the probability of accidents can be reduced.
