CN109085243B - Method and device for inspecting metal part damage - Google Patents
Method and device for inspecting metal part damage Download PDFInfo
- Publication number
- CN109085243B CN109085243B CN201811165333.4A CN201811165333A CN109085243B CN 109085243 B CN109085243 B CN 109085243B CN 201811165333 A CN201811165333 A CN 201811165333A CN 109085243 B CN109085243 B CN 109085243B
- Authority
- CN
- China
- Prior art keywords
- metal piece
- metal
- ball body
- guide tube
- sphere
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 59
- 239000002184 metal Substances 0.000 title claims abstract description 59
- 230000006378 damage Effects 0.000 title claims abstract description 37
- 238000000034 method Methods 0.000 title claims description 17
- 238000001514 detection method Methods 0.000 claims abstract description 31
- 238000006073 displacement reaction Methods 0.000 claims description 11
- 238000007689 inspection Methods 0.000 claims description 10
- 238000012544 monitoring process Methods 0.000 claims description 3
- 239000007769 metal material Substances 0.000 claims description 2
- 239000000523 sample Substances 0.000 claims 1
- 208000027418 Wounds and injury Diseases 0.000 abstract description 5
- 208000014674 injury Diseases 0.000 abstract description 5
- 230000000694 effects Effects 0.000 abstract description 4
- 230000000007 visual effect Effects 0.000 abstract description 2
- 229910000831 Steel Inorganic materials 0.000 description 29
- 239000010959 steel Substances 0.000 description 29
- 238000010009 beating Methods 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 238000005096 rolling process Methods 0.000 description 2
- 241000219109 Citrullus Species 0.000 description 1
- 235000012828 Citrullus lanatus var citroides Nutrition 0.000 description 1
- 229910000617 Mangalloy Inorganic materials 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000002592 echocardiography Methods 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000009659 non-destructive testing Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/04—Analysing solids
- G01N29/045—Analysing solids by imparting shocks to the workpiece and detecting the vibrations or the acoustic waves caused by the shocks
Landscapes
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
Abstract
The invention relates to the field of nondestructive detection, and discloses a metal part damage detection method and a metal part damage detection device. The impact on the flat surface of the metal piece is formed by utilizing the free falling body of the sphere to replace manual impact of workers, the initial impact force is uniform each time, and the interference of human factors is reduced. The sound sensor is used for measuring the sound and the frequency generated by the impact, and the sound sensor is compared with the standard value to judge the injury, so that the erroneous judgment of hearing and eyes and the injury omission condition of human factors are prevented. The vibration sensor is used for measuring the vibration value to replace the hand feeling vibration, so that the effect is more visual.
Description
Technical Field
The invention belongs to the technical field of nondestructive testing, and particularly relates to a metal part damage detection method and a device thereof.
Background
At present, the flaw detection of a plurality of metal parts mainly depends on ultrasonic waves for detection, for example, railway rails are basic bearing structures of railway tracks and are used for guiding rolling stock to run, meanwhile, contact surfaces for providing minimum resistance for rolling of wheels are required to be provided, the rails are required to have enough bearing capacity, bending strength, fracture toughness and stability, the rails used on railways are required to bear huge pressure, steel with extremely high quality is required to be used, the requirements of the railway rails on the steel are higher than those of other applications, and a small flaw can lead to rail breakage at any time when the railway rails appear, so that the train is derailed, and therefore the flaw detection is particularly important.
The high manganese steel integral casting frog rail is a rail commonly used at present, belongs to cast products, has the characteristic that grains are coarse in the rail, can scatter in the flaw detection process, so that signals received by an instrument are disordered and cannot be detected, railway workers can only judge whether injury exists by beating through a traditional small hammer, hearing echoes of the railway workers, watching the jump times and vibration feeling of the small hammer, the traditional manual operation is just like 'beating watermelons' to judge whether maturity is achieved, the experience and the feeling of workers are completely relied on, the damage omission detection and the misjudgment rate are high, unnecessary material waste can be caused, and damage pieces can be put into use, so that immeasurable serious consequences can be finally caused.
Similarly, other metal pieces that may collide with the ultrasonic flaw detection mechanism cannot be inspected smoothly at the time of ultrasonic flaw detection, and in order to ensure that these metal pieces that are not suitable for ultrasonic flaw detection can be inspected smoothly and rapidly, it is highly desirable to develop a flaw detection device that is highly suitable.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide an intelligent and digital metal part damage detection method with high damage detection rate.
The invention also provides a metal part damage inspection device which has a simple structure and is convenient to operate and capable of rapidly distinguishing the quality of the steel rail.
The technical scheme of the invention is as follows: a metal part flaw detection method includes the steps of horizontally placing a metal part, arranging a ball body capable of freely falling onto the flat surface of the metal part along a vertical path, collecting two reference values of decibel values generated when the ball body is touched with the metal part and the number of times that the ball body is touched with the metal part, and comparing the two reference values with corresponding standard values.
The invention further adopts the technical scheme that: and collecting vibration frequency and vibration displacement parameters of the metal piece at the position where the ball body touches the metal piece, and comparing the vibration frequency and the vibration displacement parameters with corresponding standard values.
The other technical scheme of the invention is as follows: the utility model provides a metalwork damage inspection device, includes the sharp stand pipe that sets up perpendicularly with metalwork smooth surface, places the spheroid in the stand pipe, and the first tip of stand pipe can be dismantled with metalwork and be connected, the second tip is placed can take place the electromagnetic means of actuation and separation with the spheroid, and the spheroid can do free fall after separating with electromagnetic means and move to touching with metalwork, and the detecting head of decibel value and touching number of times when the detectable spheroid touches with metalwork is installed to stand pipe middle section part department.
The invention further adopts another technical scheme that: the first end of the guide tube is detachably connected with the metal piece through a ring magnet.
The invention further adopts another technical scheme that: the electromagnetic device is an electromagnet.
The invention further adopts another technical scheme that: the detector head is a sound sensor.
The invention further adopts another technical scheme that: the second end of the guide tube is also provided with a level gauge for ensuring that the guide tube is vertical to the flat surface of the metal piece.
The invention further adopts another technical scheme that: the metal piece is provided with a vibration sensor at a contact position close to the ball body and the metal piece for monitoring the vibration frequency and the vibration displacement of the metal piece when the ball body contacts the metal piece.
The invention further adopts another technical scheme that: the guide tube is provided with an inlet for the ball to enter at the position close to the electromagnetic device.
The invention further adopts another technical scheme that: the guide tube is provided with an outlet near the first end for taking out the ball.
Compared with the prior art, the invention has the following characteristics:
1. the impact on the flat surface of the metal piece is formed by utilizing the free falling body of the sphere to replace manual impact of workers, the initial impact force is uniform each time, and the interference of human factors is reduced.
2. The sound sensor is used for measuring the sound and the frequency generated by the impact, and the sound sensor is compared with the standard value to judge the injury, so that the erroneous judgment of hearing and eyes and the injury omission condition of human factors are prevented.
3. The vibration sensor is used for measuring the vibration value to replace the hand feeling vibration, so that the effect is more visual.
4. The linear guide tube provides a free falling motion path for the ball body, so that the ball body is prevented from deviating, and the ball body can be impacted with the flat surface of the metal piece in the front surface, so that the optimal detection effect is ensured.
5. The electromagnetic device can attract the ball body in non-detection time, and suddenly release the ball body in detection time, so that free falling power supply of the ball body is automatically realized.
6. The level can provide a judging reference for the vertical arrangement of the straight guide tube and the flat surface of the metal piece, so that the good installation of the straight guide tube is ensured, and the friction between the ball body and the tube wall is eliminated later.
7. The inspection device has simple structure and high intelligent degree, and is combined with the design of the related alarm device in the prior art to easily realize the automatic completion of the whole detection process.
The detailed structure of the present invention is further described below with reference to the accompanying drawings and detailed description.
Drawings
Fig. 1 is a schematic structural view of a metal part damage inspection apparatus according to example 2.
Detailed Description
Example 1
The metal piece is horizontally placed, a ball body which can freely fall onto the flat surface of the metal piece along a vertical path is arranged, and the size of the damage can be judged according to the difference between the reference values and the standard values by collecting two reference values, namely a decibel value generated when the ball body is touched with the metal piece and the number of times when the ball body is touched with the metal piece, and comparing the two reference values with the corresponding standard values.
In order to further assist in confirming the damage condition, vibration frequency and vibration displacement parameters of the metal piece can be collected at the position where the ball body touches the metal piece, and compared with corresponding standard values.
Example 2
The metal piece damage inspection device in this embodiment takes a steel rail as an example, as shown in fig. 1, the damage inspection device includes a linear guide tube 1 perpendicular to the flat surface of the steel rail a, a ball 2 is placed in the guide tube 1, the diameter of the ball 2 is slightly smaller than that of the guide tube 1, the guide tube 1 and the ball 2 are made of metal materials with magnetic attraction property, a first end of the guide tube 1 is detachably connected to the steel rail a through a ring magnet 3, the ring magnet 3 can firmly attract the guide tube 1 to the steel rail a, the guide tube 1 is ensured to be stably installed, an electromagnet 4 capable of being attracted and separated from the ball 2 is placed at a second end of the guide tube 1, the electromagnet 4 is controlled to be electrified and powered off by a corresponding switch (the on-off control of the electromagnet belongs to the prior art and is not repeated herein), and the ball 2 can be separated from the electromagnet 4 after the electromagnet 4 is powered off and move freely along the guide tube 1 to touch the steel rail a.
In order to accurately collect the related touch information of the ball body 2 and the steel rail A, an effective judgment basis is provided for the steel rail damage, a detection port 11 is formed in the middle section of the guide pipe 1, a sound sensor 5 capable of detecting the decibel value and the touch times of the ball body and the steel rail is arranged at the detection port 11, and a sound sensor acquisition head is arranged at the detection port.
The vibration sensor 6 is further arranged at the contact position of the ball body and the steel rail, and is used for monitoring the vibration frequency and the vibration displacement of the steel rail when the ball body contacts the steel rail, and specifically, the vibration sensor 6 is positioned outside the guide pipe 1 and is mounted on the surface of the steel rail A.
The flaw detection device of this embodiment further includes a processor (not shown), the sound sensor 5 and the vibration sensor 6 are electrically connected with the processor, the processor stores related standard values (namely, a decibel standard value, a touch frequency standard value, a vibration frequency standard value and a vibration displacement standard value) related to judging the flaw degree of the steel rail, the processor is electrically connected with an alarm (not shown), after response signals sensed by the sound sensor 5 and the vibration sensor 6 are transmitted to the processor, the processor can compare and judge the signals with the corresponding standard values, and if it is judged that a flaw condition exists, the alarm is controlled to alarm. The specific design, electrical connection and operation of the processor and alarm are well known in the art and will not be described in detail in this embodiment.
In order to ensure that the ball body 2 can smoothly complete free falling body movement, the second end part of the guide tube 1 is further provided with a level 7 for ensuring that the flat surface of the guide tube 1 and the steel rail A are in a vertical state, specifically, the level 7 can be arranged at the top of the electromagnet 4, and the level 7 is arranged after the perpendicularity of the guide tube 1 is detected through a guiding rule, so that air bubbles of the level are centered, the vertical state of the guide tube 1 can be confirmed, and the friction between the ball body 2 and the tube wall of the guide tube 1 can be effectively eliminated.
The guide tube 1 is provided with an inlet 12 for the ball 2 to enter at a position close to the electromagnet 4, the ball 2 is convenient to plug into the guide tube 1 at any time due to the arrangement of the inlet, if the inlet is not provided, the ball is placed into the guide tube at the beginning of the installation of the guide tube, and the guide tube needs to be established on the basis of short length of the guide tube, otherwise, the suction force of the electromagnet 4 cannot suck the ball 2 at a long distance, after the inlet is provided, the guide tube 1 can be installed firstly, and when the detection is ready, the ball 2 is plugged into the guide tube from the inlet 12, and the electromagnet 4 can quickly suck the ball 2.
The guiding tube 1 is provided with an outlet 13 which can be used for taking out the ball body 2 near the first end of the guiding tube 1, the outlet can reduce the disassembly and assembly times of the guiding tube when the same steel rail needs to be detected for a plurality of times, and the ball body 2 can be timely taken out after each detection is completed, so that the situation that the ball body possibly collides in the guiding tube at will to cause mutual deformation under the condition of taking out the ball body after the guiding tube is disassembled first is avoided.
The operation process of the damage inspection device is as follows: the guide tube 1 provided with the electromagnet 4 and the sound sensor 5 is adsorbed to the place needing to be inspected of the steel rail A through the annular magnet 3, in the adsorption process, the guide tube 1 is detected through the guiding ruler, then the level 7 is arranged, after that, the direction of the guide tube 1 is properly adjusted by combining the condition of bubbles in the level 7 until the bubbles in the level are centered, and finally the guide tube 7 is fixed; mounting a vibration sensor 6 to the surface of the rail a of the near-guide tube 1; the method comprises the steps of opening an electromagnet switch, plugging a sphere 2 into the guide tube from an inlet 12 of a guide tube, enabling the sphere 2 to be adsorbed on an electromagnet 4, closing the electromagnet switch, enabling the sphere 2 to freely fall by gravity to collide with a steel rail A and make sound after the magnetic attraction disappears, enabling the sphere 2 to rebound and fall down to strike the steel rail, and certainly enabling the sphere to not rebound any more, wherein in the process, a sound sensor 5 collects the decibel value of sound and the number of times of bounce (sound) (namely the touch times) when the sphere collides each time, meanwhile, a vibration sensor 6 also collects the vibration frequency and the vibration displacement of the steel rail, and related information collected by the sound sensor 5 and the vibration sensor 6 is finally transmitted to a processor to be compared with corresponding standard values; the number of the take-off is smaller than the standard value, and the damage in the steel rail is also indicated, and when the small ball does not take-off (the number of the take-off is 0), the large damage in the steel rail is proved; when the vibration frequency and the vibration displacement value of the steel rail exceed the corresponding standard values, the damage in the steel rail is indicated again. The processor can timely control the alarm to send an alarm signal to the damaged steel rail according to the numerical comparison conditions so as to guide workers to distinguish the damage condition of the steel rail.
The whole detection process of the damage detection device can be free of personnel participation, the intelligent degree and the automation degree are high, the actual action conditions of the ball body and the steel rail are monitored by the sound sensor and the vibration sensor with higher precision, and the detection effect can be effectively ensured.
The present invention is not limited to the specific structure described above, and any method or apparatus for inspecting a flaw having substantially the same structure or design concept as the present invention falls within the scope of the present invention.
Claims (7)
1. A metal part flaw detection method is provided, and the metal part is provided with a flat surface and is characterized in that: the metal piece is horizontally placed, the damage inspection method is carried out by adopting a metal piece damage inspection device, the metal piece damage inspection device comprises a linear guide pipe (1) which is perpendicular to the flat surface of the metal piece, a ball body (2) is placed in the guide pipe (1), and the ball body is made of metal materials with magnetic attraction property; the first end part of the guide pipe (1) is detachably connected with the metal piece, the second end part of the guide pipe is provided with an electromagnetic device which can be attracted to and separated from the sphere (2), the sphere (2) can move in a free falling manner after being separated from the electromagnetic device to touch the metal piece, and a detection head which can detect the decibel value and the touch times of the sphere (2) when the sphere touches the metal piece is arranged at the middle section part of the guide pipe;
comparing the two reference values with corresponding standard values by collecting two reference values, namely a decibel value generated when the sphere touches the metal piece and the frequency of the sphere touching the metal piece;
and collecting vibration frequency and vibration displacement parameters of the metal piece at the position where the ball body touches the metal piece, and comparing the vibration frequency and the vibration displacement parameters with corresponding standard values.
2. The method for inspecting a metal part for damage according to claim 1, characterized by: the electromagnetic device is an electromagnet (4).
3. The method for inspecting a metal part for damage according to claim 1, characterized by: the probe is a sound sensor (5).
4. The method for inspecting a metal part for damage according to claim 1, characterized by: the second end part of the guide tube (1) is also provided with a level gauge (7) for ensuring that the guide tube (1) and the flat surface of the metal piece are in a vertical state.
5. The method for inspecting a metal part for damage according to claim 1, characterized by: the vibration sensor (6) is arranged at the contact position of the metal piece, which is close to the ball body (2), and the metal piece and is used for monitoring the vibration frequency and the vibration displacement of the metal piece when the ball body contacts the metal piece.
6. The method for inspecting a metal part for damage according to claim 1, characterized by: the guide tube (1) is provided with an inlet (12) which is close to the electromagnetic device and can be used for the ball body (2) to enter.
7. The method for inspecting a metal part for damage according to claim 1, characterized by: the guide tube (1) is provided with an outlet (13) near the first end for the ball (2) to be removed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811165333.4A CN109085243B (en) | 2018-10-08 | 2018-10-08 | Method and device for inspecting metal part damage |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811165333.4A CN109085243B (en) | 2018-10-08 | 2018-10-08 | Method and device for inspecting metal part damage |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109085243A CN109085243A (en) | 2018-12-25 |
| CN109085243B true CN109085243B (en) | 2024-03-12 |
Family
ID=64843132
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811165333.4A Active CN109085243B (en) | 2018-10-08 | 2018-10-08 | Method and device for inspecting metal part damage |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109085243B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111208200B (en) * | 2020-02-28 | 2020-10-20 | 北京理工大学 | Ti-Al alloy liner structure consistency detection device and detection method |
| CN112945372A (en) * | 2021-01-26 | 2021-06-11 | 深圳中慧轨道智能科技有限公司 | Sliding plate fracture monitoring devices |
| US11906467B2 (en) * | 2021-12-20 | 2024-02-20 | Pliteq Inc. | Acoustic measurement apparatus, kit, and method of use thereof |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101971017A (en) * | 2008-02-07 | 2011-02-09 | 加州理工学院 | Method and apparatus for nondestructive evaluation and monitoring of materials and structures |
| CN102759568A (en) * | 2011-04-29 | 2012-10-31 | 比亚迪股份有限公司 | Sound collection equipment |
| JP2015190909A (en) * | 2014-03-28 | 2015-11-02 | 日本碍子株式会社 | Drop impact testing machine of honeycomb structure |
| CN107436264A (en) * | 2017-08-03 | 2017-12-05 | 河海大学 | A kind of assay method of the concrete damage degree based on Non-Linear Vibration technology |
| CN206788113U (en) * | 2017-04-19 | 2017-12-22 | 镇江建科建设科技有限公司 | Floor defening effect detection means |
| CN107525848A (en) * | 2016-06-20 | 2017-12-29 | 来安中衡物联网设备科技有限公司 | The detection method and equipment of the material parameter of cement-based material |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2003096007A1 (en) * | 2002-05-08 | 2003-11-20 | Sekisui Chemical Co., Ltd. | Method and equipment for inspecting reinforced concrete pipe |
-
2018
- 2018-10-08 CN CN201811165333.4A patent/CN109085243B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101971017A (en) * | 2008-02-07 | 2011-02-09 | 加州理工学院 | Method and apparatus for nondestructive evaluation and monitoring of materials and structures |
| CN102759568A (en) * | 2011-04-29 | 2012-10-31 | 比亚迪股份有限公司 | Sound collection equipment |
| JP2015190909A (en) * | 2014-03-28 | 2015-11-02 | 日本碍子株式会社 | Drop impact testing machine of honeycomb structure |
| CN107525848A (en) * | 2016-06-20 | 2017-12-29 | 来安中衡物联网设备科技有限公司 | The detection method and equipment of the material parameter of cement-based material |
| CN206788113U (en) * | 2017-04-19 | 2017-12-22 | 镇江建科建设科技有限公司 | Floor defening effect detection means |
| CN107436264A (en) * | 2017-08-03 | 2017-12-05 | 河海大学 | A kind of assay method of the concrete damage degree based on Non-Linear Vibration technology |
Non-Patent Citations (1)
| Title |
|---|
| 黄祖泽等.钢轨探伤及防断知识.中国铁道出版社,2015,第156-157页. * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109085243A (en) | 2018-12-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109085243B (en) | Method and device for inspecting metal part damage | |
| CN110500949B (en) | Continuity detection device for rail surface abrasion | |
| CN104016099B (en) | The damage of steel cord conveyor belt longitudinal tear is in line vortex monitoring method | |
| CN107543475B (en) | Detection device for outer diameter and roundness of engine cover | |
| CN206325855U (en) | A kind of electromagnet ATE | |
| CN103018324A (en) | Automatic electromagnetic nondestructive testing method and device for in-use steel rail | |
| CN104276186B (en) | The monitoring method of a kind of point tongue and the closely connected spacing of base rail | |
| CN103913136B (en) | Ultrasonic paper thickness measuring device | |
| CN110849755A (en) | Hardness detection equipment | |
| CN109342556B (en) | Turnout rail bottom edge angle crack self-adaptive eddy current detection device and method | |
| CN218673803U (en) | Pulverized coal boiler pulverized coal bunker level meter | |
| CN202400624U (en) | Pickup device for strip steel sample plate | |
| CN103235033B (en) | A kind of Card-type electromagnetic sensor and detection method detecting in-service point tongue | |
| CN116222708A (en) | Liquid flowmeter detection equipment and detection method | |
| CN202486098U (en) | Recordable magnetic defect detector | |
| CN206819093U (en) | Magnetic separator organic efficiency monitoring device | |
| CN203178235U (en) | Card type electromagnetic sensor for detecting in-service turnout point rail | |
| CN210557958U (en) | Automatic detection and alarm device for stop of transmission roller | |
| CN203274689U (en) | Circumference diameter detector | |
| CN206876643U (en) | A kind of constant ultrasonic detecting probe of pressure | |
| CN203772236U (en) | Ultrasonic paper thickness measuring device | |
| CN205426905U (en) | Rail frame device of detecting a flaw | |
| CN206906273U (en) | A kind of Shock stress Wave detecting system | |
| CN216283252U (en) | Mechanical hole detection mechanism | |
| CN205941457U (en) | Fire oil tube assembly nut eddy current test test equipment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |