A micro-leakage gap detection system and method for internal combustion engine cylinder blocks
By using ultrasonic sensors and thermal imaging components to collaboratively detect micro-leakage gaps in the cylinder block of an internal combustion engine, and combining high-pressure gas and three-dimensional coordinate analysis, the problem of missed detection and difficulty in locating micro-leakage gaps in existing technologies has been solved, achieving accurate detection and data support.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUANGAN YAOYE MACHINERY MFG CO LTD
- Filing Date
- 2026-06-03
- Publication Date
- 2026-06-30
Smart Images
Figure CN122306327A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of detection technology, and particularly relates to a micro-leakage gap detection system and method for an internal combustion engine cylinder block. Background Art
[0002] After the casting and machining of the internal combustion engine cylinder block (especially the aluminum alloy cylinder block) of a motorcycle are completed, strict airtightness and structural integrity tests must be carried out to ensure that the manufacturing quality of the internal combustion engine cylinder block is qualified before entering the subsequent node processes, such as the assembly nodes of parts such as valve seats and valve guides.
[0003] In traditional detection technologies, the main detection method for an internal combustion engine cylinder block is to detect it by the water flooding method. The specific implementation method is to install the cylinder block on the installation cylinder block, set a water retaining fence around the cylinder block, then introduce air into the cylinder block, and at the same time introduce water into the water retaining fence to completely submerge the cylinder block. After that, the detection personnel visually check whether there are bubbles in the water, and then judge whether there are quality defects such as leakage gaps in the cylinder block.
[0004] There are many technical problems in this traditional water flooding method test. It includes relying on the visual inspection of the detection personnel to check whether there are bubbles. This will not only cause the problem of missed detection of micro-leakage gaps due to too small bubbles, but also cannot test whether there are leakage gaps in small holes. In addition, the cylinder block needs to be completely immersed in water, which will cause the ground to be slippery after the cylinder block is taken out of the water, and it also needs to wait for the cylinder block to dry before entering the subsequent assembly process. Therefore, to solve the problems of the traditional water flooding detection method, the improved technical solution is to design a specific installation tooling to completely block the main holes and small holes of the cylinder block, then introduce gas with a certain air pressure into the cylinder block through the main hole air pipe and the small hole air pipe respectively, and set a pressure detection sensor on the air path, and judge whether there is air leakage in the cylinder block according to the detection data of the pressure detection sensor.
[0005] Although the existing such air pressure detection method can simultaneously solve the problems that the water flooding method detection is too rough and the cylinder block is wet after detection, there are still many problems for the leakage detection of the cylinder block. For example, the air pressure detection method only knows whether there is leakage in the detection part, but does not know the leakage position of the detection part, cannot count the frequent leakage positions of the detection part, and cannot provide data support for the improvement of the subsequent casting process. That is, the existing air pressure detection can only solve the problem of whether the detection part is qualified or not. In addition, the existing such air pressure detection method only relies on the air pressure detection sensor. For micro-leakage gaps, due to the extremely small amount of leaked gas, it is very easy to miss detection. After the cylinder block with such micro-leakage gaps is assembled and shipped out through subsequent processes, it will cause a series of quality problems. Therefore, the existing such air pressure detection method still needs to be improved to solve the problems of high missed detection rate of micro-leakage gaps and difficulty in counting the frequent occurrence areas of leakage gaps.
[0006] Based on the above background, the inventors have designed a micro-leakage gap detection system and method for internal combustion engine cylinder blocks, which solves at least one of the above problems, and hereby submit this application. Summary of the Invention
[0007] The purpose of this application is to provide a micro-leakage gap detection system and method for internal combustion engine cylinder blocks to solve the above-mentioned problems.
[0008] To solve the above-mentioned technical problems, the present invention adopts the following solution: On the one hand, this application provides a micro-leakage gap detection system for internal combustion engine cylinder blocks, including a worktable with a gap detection station, a sealed box and a rotary table assembly disposed on the worktable, and an ultrasonic sensor and a thermal imaging assembly for collaboratively detecting micro-leakage gaps; It also includes a gas supply assembly for periodically introducing and releasing high-pressure gas into the cylinder body; The gap detection station is located inside the rotary table assembly; The ultrasonic sensor is fixed inside a sealed box, and the thermal imaging component is fixed on a rotating stage assembly. The thermal imaging component can be moved circumferentially in the gap detection station via the rotating stage assembly. The signal acquisition ends of both the thermal imaging component and the ultrasonic sensor are set towards the gap detection station. During the cycle of filling the cylinder body with high-pressure gas, ultrasonic sensors and thermal imaging components collect ultrasonic data and abnormal cold spot data to determine the location of micro-leakage gaps in the cylinder body.
[0009] Optionally, it also includes a cylinder mounting assembly located directly below the gap detection station and a sealing assembly for sealing one end of the cylinder body air hole; The air supply assembly is internally connected to the cylinder block mounting assembly; With the cylinder body mounted on the cylinder mounting assembly, the air vents of the cylinder body are connected to the air supply assembly through the cylinder mounting assembly.
[0010] Optionally, the air supply assembly includes an air supply pump, an air supply pipe, a pressure valve, and an air pressure sensor; The air supply pump is connected to the cylinder block mounting assembly via an air supply pipe; Both the pressure valve and the air pressure sensor are installed on the air supply pipe, with the air pressure sensor located at the air outlet end of the pressure valve.
[0011] Optionally, the rotary table assembly includes a drive motor and a drive gear, as well as a rotating gear ring; The drive gear is mounted on the output shaft of the drive motor; The outer peripheral wall of the rotating gear ring is provided with several driven teeth that mesh with the driving gear, and the bottom of the rotating gear ring is located on the worktable and is rotatably connected to it. The thermal imaging component is located on top of the rotating gear ring.
[0012] Optionally, the drive motor is located below the worktable, and the output shaft of the drive motor passes through the worktable and is fixedly connected to the drive gear on the same axis. The rotary table assembly also includes a rotary seat assembly disposed within the worktable, wherein the rotary gear ring is coaxially disposed with the rotary seat assembly and the rotary gear ring is fixed to the top of the rotary seat assembly; The rotating bearing assembly includes two rotating bearing bodies arranged coaxially along a vertical axis, and a plurality of ball bearing bodies located between the two rotating bearing bodies. An annular groove is provided on one side of the two rotating bearing bodies facing each other, and the ball bearing bodies are all located in the annular groove and can roll freely.
[0013] Optionally, the thermal imaging assembly includes a thermal imager and a lifting platform; The lifting platform is fixed to the rotating platform assembly, the thermal imager is fixed to the lifting platform, and the signal acquisition end of the thermal imager is set facing the gap detection station directly above the cylinder mounting assembly.
[0014] Optionally, four ultrasonic sensors are provided and evenly distributed at the four positions of the cylinder mounting assembly.
[0015] On the other hand, this application provides a method for detecting micro-leakage gaps in an internal combustion engine cylinder block, applicable to any of the micro-leakage gap detection systems for internal combustion engine cylinder blocks described above, specifically including the following steps: S1. Preliminary screening of gaps: High-pressure gas is introduced into the main body of the cylinder, and the presence and type of gaps in the main body of the cylinder are determined based on the pressure drop data and ultrasonic data. S2. Micro-leakage gap location detection: For the cylinder body where the ultrasonic data exceeds the threshold, the thermal imaging component is moved to the initial position, high-pressure gas is introduced and maintained for a period of time, and then the high-pressure gas is released and left to stand for a period of time as one data acquisition cycle. At least one data acquisition cycle of ultrasonic data and temperature difference matrix data is acquired. The thermal imaging component is moved to the next position, and the above data acquisition steps are repeated until the temperature difference matrix data of the cylinder body in all directions is acquired. Based on the temperature difference matrix data sequence acquired multiple times, the abnormal cold points in all directions are summarized and their three-dimensional coordinate data are obtained. At the same time, based on the periodically acquired ultrasonic data, the location data of the micro-leakage gap is determined and output according to the energy difference of multiple ultrasonic data. S3. Based on the three-dimensional coordinate data of the abnormal cold point and the orientation data of the micro-leakage gap, make a joint judgment and output the judgment result: if the three-dimensional coordinate data is consistent with the orientation data, then the leak is confirmed and the three-dimensional coordinate data is output; if the three-dimensional coordinate data is inconsistent with the orientation data or the three-dimensional coordinate data of the abnormal cold point is not obtained, then a suspected leak is output and a review is recommended.
[0016] Optionally, in S2, the method for obtaining the three-dimensional coordinate data of the abnormal cold point is as follows: First, a three-dimensional rectangular coordinate system is constructed with the gap detection center as the origin, and the three-dimensional model file of the cylinder body is imported into the three-dimensional rectangular coordinate system; Subsequently, temperature difference matrix data of multiple data acquisition cycles during a directional detection process is acquired. Based on the temperature difference matrix data, abnormal cold points exceeding the threshold are obtained. Using the abnormal cold points as the starting point, a ray is drawn to intersect with the outer peripheral wall of the cylinder body in the three-dimensional coordinate system to obtain the three-dimensional coordinate data of the abnormal cold points. The temperature difference matrix data represents the temperature difference amplitude at the same location within a single data acquisition period.
[0017] Optionally, in S2, the method for obtaining the orientation data of the micro-leakage gap is as follows: The number of ultrasonic sensors is four, and they are evenly distributed around the gap detection station. The azimuth range mapped by each ultrasonic sensor is preset. In multiple data acquisition cycles during a azimuth detection process, high-frequency signals are synchronously acquired and filtered during the pressure holding phase of the cylinder body to remove low-frequency noise. The location of the micro-leakage was then determined based on the energy obtained from the four ultrasonic sensors: If the ratio of the strongest energy obtained by the four ultrasonic sensors to the second strongest energy obtained by the other ultrasonic sensors exceeds a threshold, then the location of the micro-leakage gap is determined to be within the location range mapped by the ultrasonic sensor that obtained the strongest energy. If the ratio of the strongest energy obtained by the four ultrasonic sensors to the second strongest energy obtained by the other ultrasonic sensors does not exceed a threshold, then the location of the micro-leakage gap is determined to be between the location ranges mapped by the two ultrasonic sensors that obtained the strongest and second strongest energy.
[0018] The beneficial effects of this invention are: I. This application, by setting up an ultrasonic sensor and a thermal imaging component, as well as a gas supply component that periodically introduces and releases high-pressure gas into the cylinder body, enables the application to achieve full coverage of the types of gaps in the cylinder body and accurate determination of the location of micro-leakage gaps: that is, this application can use the pressure drop data of the gas supply component to determine whether there are large gaps, use ultrasonic data to determine whether there are micro-leakage gaps, and combine the determination with the thermal imaging component to output the precise location of the micro-leakage gaps, thus forming a three-level judgment technology solution for leakage gaps in the cylinder body.
[0019] This application fully utilizes the principle that the cylinder body is filled with high-pressure gas, and that the high-pressure gas generates high-frequency noise when passing through a micro-leakage gap. Based on the Joule-Thomson principle, the high-pressure gas ejected from the micro-leakage gap causes the temperature at that location to drop rapidly, even as low as -50 degrees Celsius, forming an abnormal cold spot at the micro-leakage gap. Therefore, this application, through the combined use of acoustic wave detection and temperature detection, avoids the omission of micro-leakage gaps and can detect their specific locations, effectively solving the problems of the prior art.
[0020] Second, this application periodically introduces high-pressure gas into the cylinder body and maintains the pressure, then releases the high-pressure gas and allows it to stand for a period of time. Utilizing the excellent thermal conductivity of the aluminum alloy material of the cylinder body, the temperature at the micro-leakage gap is rapidly increased. This forces the temperature at the micro-leakage gap to fluctuate in sync with the gas pressure changes inside the cylinder body. In the temperature matrix sequence, an "abnormal cold spot flashing effect" can be formed at the micro-leakage gap location, thereby stably and accurately locking the micro-leakage gap location and avoiding misjudgment.
[0021] Third, this application sets up four ultrasonic sensors located in four directions to determine the approximate location of the micro-leakage gap by using the energy difference of high-frequency ultrasound. Based on whether the precise location of the micro-leakage gap is within the approximate location determined by ultrasound, on the one hand, the confidence of the micro-leakage gap location can be further improved, and on the other hand, the thermal imaging component of this application can be directly rotated to the general location of the micro-leakage gap through the rotary table component, forming an efficient synergy between extremely low-cost coarse positioning and extremely high-precision fine positioning.
[0022] Fourth, existing single thermal imagers can only acquire two-dimensional pixel information, lacking depth scale and unable to directly output three-dimensional coordinates. Binocular or multi-view solutions are costly and complex to calibrate. This application, however, first imports the three-dimensional model of the cylinder body into a three-dimensional coordinate system. After the thermal imager detects an abnormal cold spot, it generates a spatial ray passing through the abnormal cold spot and calculates the unique nearest intersection point between the ray and the outer surface of the cylinder body model. In terms of technical effect, it achieves the equivalent measurement of "monocular ray + model constraint = three-dimensional coordinates", which enables the subsequent formation of a dataset of frequently occurring micro-leakage gaps, providing a reliable basis for process improvement or casting equipment improvement.
[0023] V. Throughout the entire testing process of this application, the thermal imaging component steps, the drive motor stops, high-pressure gas is periodically introduced and released, the thermal imaging component steps again, and the drive motor stops. During the testing period, the drive motor will not drive the rotary table component to rotate, so that the chamber is in a zero electromagnetic interference and zero mechanical vibration environment when ultrasonic data is acquired, which can effectively improve the reliability of ultrasonic data. Attached Figure Description
[0024] Figure 1 This is a schematic diagram of the main structure of Embodiment 1 of this application.
[0025] Figure 2 for Figure 1 A magnified schematic diagram of the structure at point A in the middle.
[0026] Figure 3 This is a top view of Embodiment 1 of this application.
[0027] Figure 4 This is a schematic diagram of the bearing housing in Embodiment 1 of this application.
[0028] Figure 5 This is a top view of the cylinder mounting assembly in Embodiment 1 of this application.
[0029] Figure 6 This is a cross-sectional view of the cylinder mounting base in Embodiment 1 of this application.
[0030] Figure 7 This is a schematic diagram of the detection process in Embodiment 2 of this application.
[0031] Figure 8 This is a schematic diagram of the detection logic in Embodiment 2 of this application.
[0032] Explanation of reference numerals in the attached figures: 11-Workbench, 12-Box, 2-Sealing assembly, 21-Top pressure structure, 211-Top pressure cylinder, 212-Top pressure block, 213-Guide plate, 214-Guide post, 22-Sealing structure, 221-Sealing cylinder, 222-Sealing plate, 3-Cylinder mounting assembly, 31-Cylinder mounting base, 311-Main air passage, 312-Small air passage, 32-Elastic gasket, 321-Contour groove, 322-Rectangular groove, 33-Pass Air sleeve, 331-vent main hole, 34-positioning column, 4-air supply assembly, 41-air supply pump, 42-pressure valve, 43-air pressure sensor, 5-thermal imaging assembly, 51-thermal imager, 52-lifting platform, 6-ultrasonic sensor, 7-rotary table assembly, 71-drive motor, 72-drive gear, 73-rotary gear ring, 731-driven gear, 74-rotary seat ring assembly, 741-rotary seat ring body, 742-ball bearing body. Detailed Implementation
[0033] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.
[0034] Example 1: like Figures 1 to 6 As shown, this embodiment provides a micro-leakage gap detection system for an internal combustion engine cylinder block, including a worktable 11 with a gap detection station, a sealed box 12 and a rotary table assembly 7 disposed on the worktable 11, and an ultrasonic sensor 6 and a thermal imaging assembly 5 for co-detecting micro-leakage gaps. It also includes a gas supply assembly 4 for periodically introducing and releasing high-pressure gas into the cylinder body; The gap detection station is located inside the rotary table assembly 7; The ultrasonic sensor 6 is fixed inside the sealed box 12, and the thermal imaging component 5 is fixed on the rotating stage component 7. The thermal imaging component 5 can be moved circumferentially in the gap detection station through the rotating stage component 7. The signal acquisition ends of both the thermal imaging component 5 and the ultrasonic sensor 6 are set towards the gap detection station. During the cycle of filling the cylinder body with high-pressure gas, the ultrasonic sensor 6 and the thermal imaging component 5 collect ultrasonic data and abnormal cold spot data to determine the location of micro-leakage gaps in the cylinder body.
[0035] This embodiment, by setting up an ultrasonic sensor 6 and a thermal imaging component 5, as well as a gas supply component 4 that periodically introduces and releases high-pressure gas into the cylinder body, enables this embodiment to achieve full coverage of the types of gaps in the cylinder body and accurate determination of the location of micro-leakage gaps: that is, this embodiment can use the pressure drop data of the gas supply component 4 to determine whether there are large gaps, use ultrasonic data to determine whether there are micro-leakage gaps, and combine the determination with the thermal imaging component 5 to output the precise location of the micro-leakage gaps, thus forming a three-level judgment technology solution for leakage gaps in the cylinder body.
[0036] This embodiment fully utilizes the principle that the cylinder body is filled with high-pressure gas, and that high-pressure gas generates high-frequency noise when passing through a micro-leakage gap. It also utilizes the Joule-Thomson principle, which states that when high-pressure gas is ejected from a micro-leakage gap and rapidly depressurized, the temperature at that micro-leakage gap drops rapidly, sometimes as low as -50 degrees Celsius, forming an abnormal cold spot. Therefore, this embodiment, by combining acoustic detection and temperature detection, avoids missing micro-leakage gaps and can detect their specific locations, effectively solving the problems of existing technologies.
[0037] In this embodiment, it also includes a cylinder mounting assembly 3 located directly below the gap detection station and a sealing assembly 2 for sealing one end of the air hole of the cylinder body. The air supply component 4 is internally connected to the cylinder mounting component 3; With the cylinder body mounted on the cylinder mounting assembly 3, the air vent of the cylinder body is connected to the air supply assembly 4 through the cylinder mounting assembly 3. After the cylinder body is mounted on the cylinder mounting assembly 3, it is located at the gap detection station.
[0038] In this embodiment, as Figures 1 to 3 As shown, the sealing assembly 2 includes a top-pressing structure 21 and a sealing structure 22. The top-pressing structure 21 includes a top-pressing cylinder 211, a top-pressing block 212, a guide plate 213, and a guide post 214. The top-pressing cylinder 211 is inverted and installed on the top of the housing 12 and located directly above the gap detection station. The top-pressing block 212 is installed on the output shaft of the top-pressing cylinder 211. The guide plate 213 is installed on the top of the top-pressing block 212 and is fixed between the top-pressing block 212 and the output shaft of the top-pressing cylinder 211. The guide post 214 is installed on the workbench 11. The guide plate 213 is provided with a guide hole, and the guide post 214 is installed through the guide hole of the guide plate 213. The details are omitted here.
[0039] In this embodiment, the sealing structure 22 includes a sealing cylinder 221 and a sealing plate 222. The sealing plate 222 is disposed on the output shaft of the sealing cylinder 221, and the sealing cylinder 221 is disposed on the rear side wall of the housing 12. When the cylinder body is installed on the gap detection station, the sealing plate 222 can block the through hole on the side of the cylinder body after being pushed out by the sealing cylinder 221. The sealing structure 22 in this embodiment is prior art and will not be described in detail here.
[0040] In this embodiment, the air supply component 4 includes an air supply pump 41, an air supply pipe, a pressure valve 42, and an air pressure sensor 43. The air supply pump 41 is connected to the cylinder mounting assembly 3 via an air supply pipe; The pressure valve 42 and the air pressure sensor 43 are both installed on the air supply pipe, and the air pressure sensor 43 is located at the air outlet end of the pressure valve 42. In this embodiment, the air supply pump 41, the air pressure sensor 43, the air supply pipe, the pressure valve 42 and other devices are all existing devices, and will not be described in detail here.
[0041] In this embodiment, the rotary table assembly 7 includes a drive motor 71, a drive gear 72, and a rotating gear ring 73; The drive gear 72 is mounted on the output shaft of the drive motor 71; The outer peripheral wall of the rotating gear ring 73 is provided with a plurality of driven teeth 731 that mesh with the driving gear 72. The bottom of the rotating gear ring 73 is located on the worktable 11 and is rotatably connected to it. The thermal imaging component 5 is disposed on the top of the rotating gear ring 73, and the thermal imaging component 5 scans around the outer peripheral wall of the cylinder body (not shown) through the rotating gear ring 73.
[0042] In this embodiment, the drive motor 71 drives the rotating gear ring 73 to rotate along its central axis via the drive gear 72, which is existing technology. In some embodiments, technicians can also drive the thermal imaging component 5 to rotate around the gap detection station by setting other types of rotary tables, which will not be described in detail here.
[0043] In this embodiment, the drive motor 71 is disposed below the worktable 11, and the output shaft of the drive motor 71 passes through the worktable 11 and is coaxially and fixedly connected to the drive gear 72. The rotary table assembly 7 also includes a rotary seat ring assembly 74 disposed in the worktable 11, a rotary gear ring 73 coaxially disposed with the rotary seat ring assembly 74, and the rotary gear ring 73 fixed to the top of the rotary seat ring assembly 74; The rotating seat assembly 74 includes two rotating seat bodies 741 arranged coaxially along the vertical axis, and a plurality of ball bodies 742 located between the two rotating seat bodies 741. An annular groove is provided on one side of the two rotating seat bodies 741, and the ball bodies 742 are all located in the annular groove and can roll freely.
[0044] In this embodiment, by setting the rotating seat assembly 74, the friction of the rotary table assembly 7 during rotation can be reduced, making the rotation of the rotary table assembly 7 more stable. In some embodiments, the technician may not set the rotating seat assembly 74 to reduce costs. In this embodiment, setting the rotating seat assembly 74 is only an optional preferred solution, and will not be described in detail here.
[0045] In this embodiment, the thermal imaging component 5 includes a thermal imager 51 and a lifting platform 52; The lifting platform 52 is fixed to the rotating platform assembly 7, and the thermal imager 51 is fixed on the lifting platform 52. The signal acquisition end of the thermal imager 51 is set facing the gap detection station directly above the cylinder mounting assembly 3. In this embodiment, by setting the lifting platform 52, the height of the thermal imager 51 can be easily adjusted to ensure the imaging quality of the thermal imager 51.
[0046] The thermal imager 51 in this embodiment is an existing device, which will not be described in detail here. The data acquired by the thermal imager 51 can be uploaded wirelessly, avoiding cable tangling.
[0047] In this embodiment, four ultrasonic sensors 6 are provided and evenly distributed in the four directions of the cylinder mounting assembly 3. By setting ultrasonic sensors 6 in four directions, the approximate location of the micro-leakage gap can be determined by ultrasonic sensors 6 in four directions. In some embodiments, six or eight ultrasonic sensors 6 can also be provided, which will not be elaborated here.
[0048] In this embodiment, as Figure 2 , Figure 5 and Figure 6 As shown, the cylinder mounting assembly 3 includes a cylinder mounting base 31 and an elastic gasket 32 disposed on the top of the cylinder mounting base 31. The top of the elastic gasket 32 is provided with a contour groove 321 and a rectangular groove 322, so that after the cylinder body is installed on the elastic gasket 32, its protruding part is located in the contour groove 321 and the rectangular groove 322. A positioning post 34 is also provided on the cylinder mounting base 31 to facilitate the installation of the cylinder body.
[0049] In this embodiment, the cylinder mounting assembly 3 further includes a venting sleeve 33 disposed within the cylinder mounting base 31 and protruding from the cylinder mounting base 31 and the elastic gasket 32. The venting sleeve 33 is provided with a main venting hole 331, and the cylinder mounting base 31 is provided with a main venting passage 311. The main venting passage 311 communicates with the main venting hole 331 of the venting sleeve 33. The cylinder mounting base 31 is also provided with a small venting passage 312. The top of the cylinder mounting base 31 and the top of the elastic gasket 32 are also provided with small venting holes communicating with the small venting passage 312, so that high-pressure gas can enter the small hole of the cylinder body through the small venting passage 312 and the small venting hole.
[0050] The cylinder mounting base 31, elastic gasket 32, vent sleeve 33, and positioning post 34 mentioned above in this embodiment are all existing structures and will not be described in detail here.
[0051] Example 2: like Figure 7 and Figure 8 As shown, this embodiment provides a method for detecting micro-leakage gaps in an internal combustion engine cylinder block, applicable to the micro-leakage gap detection system for an internal combustion engine cylinder block described in Embodiment 1 above. The method specifically includes the following steps: S1. Preliminary screening of gaps: High-pressure gas is introduced into the cylinder body. Based on the pressure drop data and ultrasonic data, it is determined whether there are gaps in the cylinder body and the type of gaps. In this embodiment, the presence of leakage gaps can be determined based on whether the pressure drop data exceeds a preset threshold. If the pressure drop data exceeds the threshold after the high-pressure gas is injected, it is determined that there is a large gap, and an alarm signal can be directly output. At the same time, if the pressure drop data value is extremely small and does not exceed the threshold or the pressure drop data is close to zero, it does not mean that there are no gaps. At this time, it is determined whether there is a high-frequency signal based on the ultrasonic data. If there is a high-frequency signal in the ultrasonic data, it is determined that there is a micro-leakage gap, and it is necessary to proceed to the next stage for precise judgment. When the pressure drop data is close to zero and no corresponding high-frequency signal is obtained in the ultrasonic data, it is determined that the part is a normal part and there are no large gaps or micro-leakage gaps.
[0052] In this embodiment, this step is only a rough judgment. If there is a large gap, it will not proceed to the next step of gap location judgment, because this situation is mainly due to unexpected circumstances and is unlikely to occur frequently. Otherwise, the gap location can be judged by the naked eye and the non-conforming nodes of the entire production line can be tracked. The purpose of this embodiment is mainly to judge the location of micro-leakage gaps that are difficult to observe with the naked eye.
[0053] S2. Micro-leakage gap location detection: For the cylinder body where the ultrasonic data exceeds the threshold, the thermal imaging component 5 is moved to the initial position, high-pressure gas is introduced and maintained for a period of time, and then the high-pressure gas is released and left to stand for a period of time as one data acquisition cycle. At least one data acquisition cycle of ultrasonic data and temperature difference matrix data is acquired. The thermal imaging component 5 is moved to the next position, and the above data acquisition steps are repeated until the temperature difference matrix data of the cylinder body in all directions is acquired. Based on the temperature difference matrix data sequence acquired multiple times, the abnormal cold points in all directions are summarized and their three-dimensional coordinate data are obtained. At the same time, based on the periodically acquired ultrasonic data, the location data of the micro-leakage gap is determined and output according to the energy difference of multiple ultrasonic data. This embodiment utilizes the excellent thermal conductivity of the aluminum alloy material of the cylinder body to rapidly raise the temperature at the micro-leakage gap by periodically introducing and maintaining high pressure into the cylinder body, followed by releasing the high pressure gas and allowing it to stand for a period of time. This allows the temperature at the micro-leakage gap to fluctuate in sync with the gas pressure changes inside the cylinder body. During a high-pressure holding and releasing cycle, a temperature difference matrix sequence can be generated based on the temperature matrix sequence obtained by the thermal imager 51. The location of abnormal cold points is marked by the temperature difference amplitude, instead of simply relying on the coordinates of abnormal cold points in the thermal imager 51 to directly mark the micro-leakage gap. This avoids misjudgment when there are cold areas such as oil spots on the cylinder body.
[0054] In this embodiment, the high-pressure gas introduction and release cycle can be 10 seconds / time, that is, a data acquisition cycle every 20 seconds. Two to three data acquisition cycles are required for each position. Generally speaking, there is also an optimization scheme to reduce the overall detection cycle time. That is, the approximate position is determined first based on the ultrasonic data, and then the thermal imager 51 is rotated to the approximate position of the micro-leakage gap. The specific location of the abnormal cold point can be determined in 3 to 5 minutes. If the thermal imager 51 is rotated to the approximate position generated based on the ultrasonic data and no abnormal cold point is detected, the thermal imager 51 needs to be rotated to other positions to detect the abnormal cold point until all positions are detected. That is, the position where the micro-leakage gap is likely to exist can be detected first, and then the position where the gap is less likely to exist can be detected, thereby reducing the detection cycle of the micro-leakage gap of the cylinder body.
[0055] In this embodiment, multiple detection orientations can be set, such as Figure 1 and Figure 3 As shown, due to the presence of the sealing structure 22, only 11 detection positions can be detected. Therefore, if no abnormal cold point is found after completing the detection of abnormal cold points in 11 detection positions, it is necessary to check and repeat the detection. If no abnormal cold point is found after repeating the detection, it is necessary to mark it and trigger an alarm.
[0056] S3. Based on the three-dimensional coordinate data of the abnormal cold point and the orientation data of the micro-leakage gap, make a joint judgment and output the judgment result: if the three-dimensional coordinate data is consistent with the orientation data, then the leak is confirmed and the three-dimensional coordinate data is output; if the three-dimensional coordinate data is inconsistent with the orientation data or the three-dimensional coordinate data of the abnormal cold point is not obtained, then a suspected leak is output and a review is recommended.
[0057] In this embodiment, the method for obtaining the three-dimensional coordinate data of the abnormal cold point in S2 is as follows: First, a three-dimensional rectangular coordinate system is constructed with the gap detection center as the origin, and the three-dimensional model file of the cylinder body is imported into the three-dimensional rectangular coordinate system; Subsequently, temperature difference matrix data of multiple data acquisition cycles during a directional detection process is acquired. Based on the temperature difference matrix data, abnormal cold points exceeding the threshold are obtained. Using the abnormal cold points as the starting point, a ray is drawn to intersect the outer peripheral wall of the cylinder body in the three-dimensional rectangular coordinate system to obtain the three-dimensional coordinate data of the abnormal cold points. The temperature difference matrix data represents the temperature difference amplitude at the same location within a single data acquisition period.
[0058] In this embodiment, setting up a three-dimensional rectangular coordinate system and importing the three-dimensional model file of the cylinder body into the three-dimensional rectangular coordinate system are conventional techniques. In this embodiment, it is also necessary to import the three-dimensional model file of the thermal imager 51 into the three-dimensional rectangular coordinate system so that it is modeled in the three-dimensional rectangular coordinate system. Then, a ray is drawn at the abnormal cold point location and intersects with the three-dimensional model of the cylinder body to obtain the three-dimensional coordinate data of the abnormal cold point.
[0059] In this embodiment, in S2, the method for obtaining the orientation data of the micro-leakage gap is as follows: The number of ultrasonic sensors 6 is four, and they are evenly distributed around the gap detection station. The azimuth range mapped by each ultrasonic sensor 6 is preset. In multiple data acquisition cycles during a azimuth detection process, high-frequency signals are synchronously acquired and filtered during the pressure holding phase of the cylinder body to remove low-frequency noise. The location of the micro-leakage gap was then determined based on the energy acquired by the four ultrasonic sensors 6. If the ratio of the strongest energy obtained by the four ultrasonic sensors 6 to the second strongest energy obtained by the other ultrasonic sensors 6 exceeds a threshold, then it is determined that the location of the micro-leakage gap is within the location range mapped by the ultrasonic sensor 6 that obtained the strongest energy. If the ratio of the strongest energy obtained by the four ultrasonic sensors 6 to the second strongest energy obtained by the other ultrasonic sensors 6 does not exceed a threshold, then the location of the micro-leakage gap is determined to be between the location ranges mapped by the two ultrasonic sensors 6 that obtained the strongest and second strongest energy.
[0060] Existing single thermal imagers can only acquire two-dimensional pixel information, lacking depth scale and unable to directly output three-dimensional coordinates. Binocular or multi-view solutions are costly and complex to calibrate. This application, however, first imports the three-dimensional model of the cylinder body into a three-dimensional coordinate system. After the thermal imager detects an abnormal cold spot, it generates a spatial ray that passes through the abnormal cold spot from the optical center and calculates the unique nearest intersection point between the ray and the outer surface of the cylinder body model. Technically, this achieves the equivalent measurement of "monocular ray + model constraint = three-dimensional coordinates". This allows for the subsequent formation of a dataset of frequently occurring micro-leakage gaps, providing a reliable basis for process improvement or casting equipment upgrades.
[0061] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.
Claims
1. A micro-leakage gap detection system for an internal combustion engine cylinder block, comprising a worktable (11) with a gap detection station, characterized in that, Includes a sealed enclosure (12) and a rotary table assembly (7) mounted on a worktable (11), as well as an ultrasonic sensor (6) and a thermal imaging assembly (5) for the collaborative detection of micro-leaks. It also includes a gas supply assembly (4) for periodically introducing and releasing high-pressure gas into the cylinder body; The gap detection station is located inside the rotary table assembly (7); The ultrasonic sensor (6) is fixed inside the sealed box (12), and the thermal imaging component (5) is fixed on the rotating stage component (7). The thermal imaging component (5) can move circumferentially in the gap detection station through the rotating stage component (7). The signal acquisition ends of the thermal imaging component (5) and the ultrasonic sensor (6) are both set towards the gap detection station. During the cycle of filling the cylinder body with high-pressure gas, the ultrasonic sensor (6) and the thermal imaging component (5) collect ultrasonic data and abnormal cold spot data to determine the location of micro-leakage gaps.
2. The micro-leakage gap detection system for an internal combustion engine cylinder block according to claim 1, characterized in that, It also includes a cylinder mounting assembly (3) located directly below the gap detection station and a sealing assembly (2) used to seal one end of the cylinder body air hole. The air supply assembly (4) is internally connected to the cylinder mounting assembly (3); With the cylinder body mounted on the cylinder mounting assembly (3), the air vent of the cylinder body is connected to the air supply assembly (4) through the cylinder mounting assembly (3).
3. The micro-leakage gap detection system for an internal combustion engine cylinder block according to claim 2, characterized in that, The air supply assembly (4) includes an air supply pump (41), an air supply pipe, a pressure valve (42), and an air pressure sensor (43). The air supply pump (41) is connected to the cylinder mounting assembly (3) via an air supply pipe; The pressure valve (42) and the air pressure sensor (43) are both installed on the air supply pipe, and the air pressure sensor (43) is located at the air outlet end of the pressure valve (42).
4. The micro-leakage gap detection system for an internal combustion engine cylinder block according to claim 1, characterized in that, The rotary table assembly (7) includes a drive motor (71) and a drive gear (72), as well as a rotating gear ring (73). The drive gear (72) is mounted on the output shaft of the drive motor (71); The outer peripheral wall of the rotating gear ring (73) is provided with a number of driven teeth (731) that mesh with the driving gear (72). The bottom of the rotating gear ring (73) is located on the worktable (11) and is rotatably connected to it. The thermal imaging component (5) is located on top of the rotating gear ring (73).
5. A micro-leakage gap detection system for an internal combustion engine cylinder block according to claim 4, characterized in that, The drive motor (71) is located below the worktable (11), and the output shaft of the drive motor (71) passes through the worktable (11) and is coaxially and fixedly connected with the drive gear (72). The rotary table assembly (7) also includes a rotary seat assembly (74) disposed in the worktable (11), a rotary gear ring (73) coaxially disposed with the rotary seat assembly (74), and the rotary gear ring (73) fixed to the top of the rotary seat assembly (74); The rotating seat assembly (74) includes two rotating seat bodies (741) arranged coaxially along the vertical direction, and a number of ball bodies (742) located between the two rotating seat bodies (741). An annular groove is provided on the opposite side of the two rotating seat bodies (741), and the ball bodies (742) are all located in the annular groove and can roll freely.
6. The micro-leakage gap detection system for an internal combustion engine cylinder block according to claim 1, characterized in that, The thermal imaging assembly (5) includes a thermal imager (51) and a lifting platform (52); The lifting platform (52) is fixed to the rotating platform assembly (7), and the thermal imager (51) is fixed on the lifting platform (52). The signal acquisition end of the thermal imager (51) is set facing the gap detection station directly above the cylinder mounting assembly (3).
7. A micro-leakage gap detection system for an internal combustion engine cylinder block according to claim 1, characterized in that, The ultrasonic sensors (6) are provided in four positions and are evenly distributed in the four directions of the cylinder mounting assembly (3).
8. A method for detecting micro-leakage gaps in an internal combustion engine cylinder block, applicable to the micro-leakage gap detection system for an internal combustion engine cylinder block as described in any one of claims 1 to 7, characterized in that, Specifically, the following steps are included: S1. Preliminary screening of gaps: High-pressure gas is introduced into the main body of the cylinder, and the presence and type of gaps in the main body of the cylinder are determined based on the pressure drop data and ultrasonic data. S2, Micro-leakage gap location detection: For the cylinder body whose ultrasonic data exceeds the threshold, the thermal imaging component (5) is moved to the initial orientation, high-pressure gas is introduced and pressure is maintained for a period of time, then the high-pressure gas is released and left to stand for a period of time as a data acquisition cycle, and ultrasonic data and temperature difference matrix data of at least one data acquisition cycle are acquired. The thermal imaging component (5) is moved to the next position, and the above data acquisition steps are repeated until the temperature difference matrix data of the cylinder body in all directions is acquired. Based on the temperature difference matrix data sequence acquired multiple times, the abnormal cold points in all directions are summarized and their three-dimensional coordinate data are obtained. At the same time, based on the periodically acquired ultrasonic data, the location data of the micro-leakage gap is determined and output according to the energy difference of multiple ultrasonic data. S3. Based on the three-dimensional coordinate data of the abnormal cold point and the orientation data of the micro-leakage gap, make a joint judgment and output the judgment result: if the three-dimensional coordinate data is consistent with the orientation data, then the leak is confirmed and the three-dimensional coordinate data is output; if the three-dimensional coordinate data is inconsistent with the orientation data or the three-dimensional coordinate data of the abnormal cold point is not obtained, then a suspected leak is output and a review is recommended.
9. A method for detecting micro-leakage gaps in an internal combustion engine cylinder block according to claim 8, characterized in that, In S2, the method for obtaining the three-dimensional coordinate data of the abnormal cold point is as follows: First, a three-dimensional rectangular coordinate system is constructed with the gap detection center as the origin, and the three-dimensional model file of the cylinder body is imported into the three-dimensional rectangular coordinate system; Subsequently, temperature difference matrix data of multiple data acquisition cycles during a directional detection process is acquired. Based on the temperature difference matrix data, abnormal cold points exceeding the threshold are obtained. Using the abnormal cold points as the starting point, a ray is drawn to intersect with the outer peripheral wall of the cylinder body in the three-dimensional coordinate system to obtain the three-dimensional coordinate data of the abnormal cold points. The temperature difference matrix data represents the temperature difference amplitude at the same location within a single data acquisition period.
10. A method for detecting micro-leakage gaps in an internal combustion engine cylinder block according to claim 8, characterized in that, In S2, the method for obtaining the orientation data of the micro-leakage gap is as follows: The number of ultrasonic sensors (6) is four, and they are evenly distributed around the gap detection station. The azimuth range mapped by each ultrasonic sensor (6) is preset. In multiple data acquisition cycles during a azimuth detection process, high-frequency signals are synchronously acquired and filtered during the pressure holding phase of the cylinder body to remove low-frequency noise. The location data of the micro-leakage gap was then determined based on the energy obtained from the four ultrasonic sensors (6): If the ratio of the strongest energy obtained by the four ultrasonic sensors (6) to the second strongest energy obtained by the other ultrasonic sensors (6) exceeds the threshold, then it is determined that the location of the micro-leakage gap is within the location range mapped by the ultrasonic sensor (6) that obtained the strongest energy. If the ratio of the strongest energy obtained by the four ultrasonic sensors (6) to the second strongest energy obtained by the other ultrasonic sensors (6) does not exceed the threshold, then the orientation of the micro-leakage gap is determined to be between the orientation ranges mapped by the two ultrasonic sensors (6) that obtained the strongest and second strongest energy.