Burr-shaped cast-in cylinder liner and measurement method therefor

Abstract

The present application relates to the technical field of cylinder liners and measurement thereof, and specifically relates to a burr-shaped cast-in cylinder liner and a measurement method therefor. The cylinder liner is made of cast iron, and is cast into a cylinder block by means of a die casting or gravity casting process, and a plurality of burrs are formed on the outer peripheral surface of the cylinder liner. At least one of the burrs satisfies: in the burr-shaped cast-in cylinder liner, the diameter of the burr at a positon 0.25 mm from the top end is L1, the diameter of the burr at a position 0.4 mm from the top end is L2, and the ratio of the diameter L1 to the diameter L2 satisfies 0.65≤L1:L2≤1.15. By means of limiting the diameters of the burr at two special positions from the top end, the specific shape of the burr is defined, so as to ensure the bonding rate between a single burr and the cylinder block and the bonding rate between the cylinder liner and the cylinder block, thereby ensuring good heat dissipation between the cylinder liner and the cylinder block, and ensuring that the cylinder liner does not deform during operation.

Description

A burr-like cast-in cylinder liner and its inspection method

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411622123.9, filed on November 14, 2024, entitled "A Burr-like Cast-in Cylinder Liner and Its Detection Method", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of cylinder liners and their testing technology, specifically to a burr-shaped cast-in cylinder liner and its testing method. Background Technology

[0004] A cast-in cylinder liner is a cylindrical part that is cast into the cylinder block. During the operation of an internal combustion engine, the inner surface of the cylinder liner is directly subjected to high-temperature and high-pressure combustion gases and is constantly subjected to high-speed sliding friction with the piston rings and piston skirt. Therefore, the cylinder liner must have a good fit with the cylinder block to prevent movement, and at the same time, it must be able to conduct the heat from the cylinder liner surface to the cylinder block, thereby ensuring that the cylinder liner maintains an appropriate temperature. In other words, the cylinder liner and the cylinder block have both good bonding strength and excellent heat dissipation performance.

[0005] In existing technologies, to increase the bonding strength between the cylinder liner and the engine block, raised structures, i.e., burrs, are typically provided on the surface of the cylinder liner. Burrs can be dumbbell-shaped, columnar, spike-shaped, eagle-beak-shaped, or have a series of thorns or worm-like shapes. Dumbbell-shaped or spike-shaped raised structures are the most common. The specific shape and size of the burrs affect the bonding ratio between the cylinder liner and the cylinder block. The bonding ratio between the cylinder liner and the cylinder block has a significant impact on the effective heat dissipation of the cylinder liner. By increasing the bonding ratio between a single burr and the cylinder block, and thus increasing the overall bonding ratio between the cylinder liner and the cylinder block, heat dissipation can be effectively improved. Therefore, those skilled in the art need to study how different burr shapes can effectively improve the bonding ratio between the cylinder liner and the cylinder block. Summary of the Invention

[0006] Therefore, the technical problem to be solved by this application is how to solve the problem of insufficient bonding rate between a single burr and the cylinder block, and insufficient bonding rate between the cylinder liner and the cylinder block, leading to poor heat dissipation of the cylinder liner in the prior art. To this end, this application provides a burr-shaped cast-in cylinder liner, the cylinder liner being made of cast iron and cast into the cylinder block by die casting or gravity casting processes, with multiple burrs formed on the outer peripheral surface of the cylinder liner; at least one of the burrs satisfies the following conditions:

[0007] The diameter of the burr at a position 0.25 mm from the tip is L1, and the diameter of the burr at a position 0.4 mm from the tip is L2; ​​the ratio of diameter L1 to diameter L2 is: 0.65 ≤ L1: L2 ≤ 1.15.

[0008] The burr may include a necked protrusion located 0.2 mm to 0.35 mm from the tip of the burr; or the burr may include a pointed, cone-shaped protrusion.

[0009] Optionally, the necked protrusions in the above-described structure can be dumbbell-shaped burrs;

[0010] At the diameter L1 position of the dumbbell-shaped burr, the outer contour of the dumbbell-shaped burr has points A1 and A3, and the line connecting points A1 and A3 is the diameter L1; at the tip of the outer contour of the dumbbell-shaped burr, there is also a point A2; points A2 and A1 are located on the same longitudinal section of the dumbbell-shaped burr, the line connecting points A1 and A2 is line A1A2, the line connecting points A1 and A3 is line A1A3, and the angle between the extension of line A1A3 and line A1A2 is α2;

[0011] At the diameter L2 position of the dumbbell-shaped burr, the outer contour of the dumbbell-shaped burr has points A4 and A5, and the line connecting points A4 and A5 is the diameter L2; points A4 and A1 are located on the same longitudinal section of the dumbbell-shaped burr, and the line connecting points A4 and A1 is line A4A1, the line connecting points A4 and A5 is line A4A5, and the included angle between line A4A1 and line A4A5 is α1;

[0012] The ratio of α1 to α2 is in the range of α1:α2≥0.5.

[0013] In the above structure, optionally, the ratio of α1 to α2 is in the range of: α1:α2≤2.1.

[0014] Optionally, the number of dumbbell-shaped burrs on the cylinder liner within a 1 square centimeter area is 30 to 80.

[0015] Optionally, in the above structure, the number of dumbbell-shaped burrs passing through any 10mm long line segment on the outer circumferential surface of the cylinder liner is 4 to 8.

[0016] Optionally, the pointed, conical protrusions described above can be cone-shaped burrs;

[0017] At the diameter L1 position of the conical burr, there are points A1 and A3 on the outer contour of the conical burr, and the line connecting points A1 and A3 is the diameter L1; there is also point A2 on the outer contour of the conical burr, and point A2 is located 0.1 mm away from the tip of the burr; points A2 and A1 are located on the same longitudinal section of the conical burr, and the line connecting points A1 and A2 is line A1A2, and the line connecting points A1 and A3 is line A1A3, and the included angle between line A1A3 and line A1A2 is α2;

[0018] At the diameter L2 position of the conical burr, the outer contour of the conical burr has points A4 and A5, and the line connecting points A4 and A5 is the diameter L2; points A4 and A1 are located on the same longitudinal section of the conical burr, and the line connecting points A4 and A1 is line A4A1, the line connecting points A4 and A5 is line A4A5, and the included angle between line A4A1 and line A4A5 is α1;

[0019] The ratio of α1 to α2 is in the range of α1:α2≥0.25.

[0020] In the above structure, optionally, the ratio of α1 to α2 is in the range of: α1:α2≤1.0.

[0021] Optionally, the number of tapered burrs on the cylinder liner within a 1 square centimeter area is 45 to 85.

[0022] Optionally, in the above structure, the number of tapered burrs passing through any 10mm long line segment on the outer circumferential surface of the cylinder liner is 6 to 11.

[0023] A method for detecting burrs in a cast-in cylinder liner, comprising:

[0024] A method for detecting the diameter of a burr at positions 0.25 mm and 0.4 mm from its tip includes the following steps:

[0025] Step S101: Use the end position of the cylinder liner or the vertical cut surface in the radial direction of the cylinder liner as the detection surface.

[0026] Step S102: Place the inspection surface of the cylinder liner under the objective lens of an ultra-depth-of-field microscope;

[0027] Step S103: Rotate the coarse and fine focus knobs until a clear image is seen on the computer screen.

[0028] Step S104: Using the image from step S103, find the positions of the burr 0.25mm and 0.4mm from the top of the burr, respectively, from the top of the burr downwards and along the vertical direction; wherein, the position of the burr from the top of the burr is selected as the highest point of the longitudinal section of the burr, and the allowable error of the distance between the burr and the top of the burr is ±0.018mm.

[0029] Step S105: Detect the intercept L1 value at the position 0.25mm from the top of the burr and the intercept L2 value at the position 0.4mm from the top of the burr in step S104; wherein, the diameters at the positions 0.25mm and 0.4mm from the top of the burr are the horizontal lengths of the longitudinal section of the burr.

[0030] Optionally, the burr detection method described above can be applied to the aforementioned burr-shaped cast-in cylinder liner.

[0031] Optionally, the above-mentioned burr detection method can be applied to burr-shaped cast-in cylinder liners to detect the included angles α1 and α2 of dumbbell-shaped burrs.

[0032] The detection method for the included angles α1 and α2 of the dumbbell-shaped burrs is as follows:

[0033] Step S201: According to steps S101 to S104, locate the dumbbell-shaped burrs at positions 0.25mm and 0.4mm from the tip, respectively;

[0034] In step S202, at a position 0.25mm from the tip of the burr in step S201, select points A1 and A3 on the outer contour of the dumbbell-shaped burr; select point A2 on the tip of the outer contour of the dumbbell-shaped protrusion of the dumbbell-shaped burr; wherein, point A2 is the outermost position of the dumbbell-shaped protrusion in the longitudinal section of the burr in step S103 and the ultra-depth-of-field microscope image, and the allowable error of the outermost position of the dumbbell-shaped protrusion is ±0.018mm; measure the angle α2 between the extension of line A1A3 and line A1A2 using the angle measurement function of the ultra-depth-of-field microscope software;

[0035] In step S201, at a distance of 0.4 mm from the top of the burr, select points A4 and A5 on the outer contour of the dumbbell-shaped burr; use the angle measurement function of the ultra-depth-of-field microscope software to measure the included angle α1 between the connecting lines A4A1 and A4A5.

[0036] Optionally, the above-mentioned burr detection method is applied to burr-shaped cast-in cylinder liners to detect the included angles α1 and α2 of the conical burrs.

[0037] The detection method for the included angles α1 and α2 of the conical burr is as follows:

[0038] Step S301: According to steps S101 to S104, find the positions of the conical burr 0.25mm and 0.4mm from the top respectively;

[0039] In step S302, at a position 0.25 mm from the top of the burr in step S301, select points A1 and A3 on the outer contour of the conical burr; using the ultra-depth-of-field microscope image from step S103, find the position 0.1 mm from the top of the burr, moving downwards along the vertical direction; at the position 0.1 mm from the top of the burr, select point A2 on the outer contour of the longitudinal section of the burr in the ultra-depth-of-field microscope image; using the angle measurement function of the ultra-depth-of-field microscope software, measure the angle α2 between the extension of line A1A3 and line A1A2.

[0040] In step S301, at a distance of 0.4 mm from the top of the burr, select points A4 and A5 on the outer contour of the conical burr; use the angle measurement function of the ultra-depth-of-field microscope software to measure the included angle α1 between the connecting lines A4A1 and A4A5.

[0041] In this embodiment, the binding rate measurement method specifically includes the following steps:

[0042] Step S1: Die-cast the cylinder liner into the cylinder body. The aluminum molten metal melting temperature is controlled within the range of 700℃ to 720℃, and the pouring temperature is controlled within the range of 650℃ to 680℃. The cylinder liner preheating temperature is controlled at 130-150℃. A 28000KN die-casting machine is used, with a slow injection speed of 0.2m / s and a fast injection speed of 5.5m / s. The final pressure is set to 45MPa.

[0043] Step S2: Cut a ring from the top of the die-cast cylinder block 25-35mm away from the top of the cylinder liner, and cut a ring from the tail of the die-cast cylinder block 25-35mm away from the end of the cylinder liner.

[0044] Next, the annular end faces of the top and bottom of the cylinder liner are sanded with sandpaper, passing through 180-grit, 400-grit, and 800-grit wet sandpaper respectively, and polished on a polishing machine as needed.

[0045] Step S3: After grinding and polishing, inspect the bonding rate between the aluminum cylinder block and the outer diameter of the cylinder liner at the top and bottom of the cylinder liner. The specific inspection locations are as shown in Figure 6, at four 10mm circumference segments of the outer diameter of the cylinder liner at 90-degree intervals. The specific inspection method is as follows:

[0046] Step S301: Using a super depth-of-field microscope, measure the length of porosity within a circumference of 10000μm along the burr surface; wherein, under the microscope, visually observe that there is a gap between the cast iron of the aluminum cylinder block and the cylinder liner, which indicates that there is a pore at that location; measure the length of the gap, which is the length of the pore.

[0047] Step S302: Calculate the bonding rate between the aluminum cylinder block and the cylinder liner outer diameter using the bonding rate calculation formula: Bonding rate = (100 - (∑porosity length))2 / 100000000))%; where the length unit of the porosity is μm.

[0048] The technical solution of this application has the following advantages:

[0049] 1. The burr-shaped cast-in cylinder liner provided in this application has multiple burrs formed on its outer circumferential surface. The diameter of the burr at a position 0.25 mm from the tip is defined as L1, and the diameter of the burr at a position 0.4 mm from the tip is defined as L2. The ratio of diameter L1 to diameter L2 is limited to: 0.65 ≤ L1: L2 ≤ 1.15.

[0050] The necked-up protrusion is positioned 0.2mm to 0.35mm from the tip of the burr, constituting a necked structure. Therefore, the 0.25mm distance from the tip falls within the necking range of the dumbbell-shaped burr. Furthermore, the 0.4mm distance from the tip represents the burr's proximity to the outer circumference of the cylinder liner, a position that affects the bonding strength between the burr and the cylinder liner, as well as the burr's shape characteristics. In this application, the ratio of diameter L1 to diameter L2 is limited to 0.65 ≤ L1: L2 ≤ 1.15. Within this ratio range, dumbbell-shaped burrs are necked-up protrusions, and conical burrs are pointed cone-shaped protrusions. Both types of burrs exhibit a higher bonding rate between a single burr and the cylinder block, thereby improving the bonding rate between the cylinder liner and the cylinder block. This ensures the overall structure of the cylinder liner and the heat transfer capability of the cylinder block, guaranteeing excellent heat dissipation performance of the cylinder liner.

[0051] 2. The burr-shaped cast-in cylinder liner provided in this application has a dumbbell-shaped burr with a diameter L1 position and the outer contour of the dumbbell-shaped burr having points A1 and A3, the line connecting points A1 and A3 being the diameter L1; the tip of the outer contour of the dumbbell-shaped burr at the dumbbell-shaped protrusion position also has a point A2; points A2 and A1 are located on the same longitudinal section of the dumbbell-shaped burr, the line connecting points A1 and A2 is line A1A2, the line connecting points A1 and A3 is line A1A3, and the angle between the extension of line A1A3 and line A1A2 is α2;

[0052] At the diameter L2 position of the dumbbell-shaped burr, there are points A4 and A5 on the outer contour of the dumbbell-shaped burr, and the line connecting points A4 and A5 is the diameter L2; points A4 and A1 are located on the same longitudinal section of the dumbbell-shaped burr, and the line connecting points A4 and A1 is the line A4A1, the line connecting points A4 and A5 is the line A4A5, and the included angle between the lines A4A1 and A4A5 is α1;

[0053] The range of the ratio of α1 to α2 is: α1:α2≥0.5.

[0054] Specifically, points A2 and A1 are located on the same cutting plane in the ultra-depth-of-field microscope image, thus effectively ensuring that points A2 and A1 are on the same vertical plane of the dumbbell-shaped burr. Similarly, points A4 and A1 are located on the same cutting plane in the ultra-depth-of-field microscope image, thus effectively ensuring that points A4 and A1 are on the same vertical plane of the dumbbell-shaped burr.

[0055] Under the above conditions, the smaller the value of α1, the closer the dumbbell-shaped burr is to the outer circumferential surface of the cylinder liner, that is, the more flat the lower middle part of the dumbbell-shaped burr tends to be. When the lower middle part of the dumbbell-shaped burr tends to be flat, the contact area between the dumbbell-shaped burr and the outer circumferential surface of the cylinder liner increases, and the connection between the dumbbell-shaped burr and the outer circumferential surface of the cylinder liner is firm and less prone to breakage. Of course, if the value of α1 is too large, the bottom of the dumbbell-shaped burr on the cylinder liner will have a large inverted cone shape. When shot blasting to remove the coating, coating and other impurities are easily left at the necking point and root of the burr. This can easily lead to inclusions and porosity on the mating surface between the burr root and the aluminum cylinder block during die casting, resulting in a decrease in the bonding rate between the cylinder liner and the cylinder block.

[0056] Under the above conditions, α2 defines the structure of the necking position of the dumbbell-shaped burr. When α2 is within an appropriate range, the bonding rate between a single burr and the cylinder block is high, and the bonding rate between the cylinder liner and the cylinder block is also high, thereby ensuring that the overall structure of the cylinder liner has excellent heat dissipation capabilities.

[0057] Furthermore, this application specifies that the ratio of α1 to α2 in the dumbbell-shaped burrs is α1:α2≥0.5. When α1 and α2 are within the above-mentioned ratio range, the bonding rate between each burr and the cylinder block is high, and the bonding rate between the cylinder liner and the cylinder block is also high, thereby ensuring that the cylinder liner has excellent heat dissipation capabilities.

[0058] 3. The burr-shaped cast-in cylinder liner provided in this application further specifies that the ratio of α1 to α2 in the dumbbell-shaped burrs is within the range of 0.5 ≤ α1: α2 ≤ 2.1. When α1 and α2 are within the above-mentioned ratio range, it can effectively ensure a high bonding rate between each burr and the cylinder block, thereby ensuring that the overall structure of the cylinder liner has excellent heat dissipation capabilities.

[0059] 4. The burr-shaped cast-in cylinder liner provided in this application has 30 to 80 dumbbell-shaped burrs within a 1 square centimeter area.

[0060] In this application, the number of dumbbell-shaped burrs within a 1 square centimeter area is 30 to 80, more preferably 30 to 55. A suitable number of dumbbell-shaped burrs ensures the bonding rate between the cylinder liner's outer surface and the cylinder block. This increased bonding rate effectively guarantees the heat dissipation capacity of the overall cylinder liner structure, while simultaneously improving the bonding strength between the overall cylinder liner structure and the cylinder block.

[0061] 5. The burr-shaped cast-in cylinder liner provided in this application has dumbbell-shaped burrs on any 10mm long line segment on the outer circumference of the cylinder liner, and the number of dumbbell-shaped burrs passing through is 4 to 8.

[0062] By limiting the number of dumbbell-shaped burrs passing through any 10mm long line segment on the outer circumference of the cylinder liner, the burr density on the outer circumference of the cylinder liner can be effectively controlled. A suitable dumbbell-shaped burr density ensures the bonding rate between the cylinder liner's outer surface and the cylinder block. An improved bonding rate effectively ensures the heat dissipation capacity of the overall cylinder liner structure, while simultaneously increasing the bonding strength between the overall cylinder liner structure and the cylinder block.

[0063] 6. The burr-shaped cast-in cylinder liner provided in this application has points A1 and A3 on the outer contour of the conical burr at a diameter L1 position. Points A1 and A3 are located 0.25 mm from the tip of the burr, and the line connecting points A1 and A3 is the diameter L1. Point A2 is also located on the outer contour of the conical burr, 0.1 mm from the tip of the burr. Points A2 and A1 are located on the same longitudinal section of the dumbbell-shaped burr. The line connecting points A1 and A2 is line A1A2, and the line connecting points A1 and A3 is line A1A3. The angle between line A1A3 and line A1A2 is α2.

[0064] At the diameter L2 position of the conical burr, the outer contour of the conical burr has points A4 and A5, which are located 0.4 mm away from the tip of the burr. The line connecting points A4 and A5 is the diameter L2. Points A4 and A1 are located on the same longitudinal section of the conical burr. The line connecting points A4 and A1 is line A4A1, and the line connecting points A4 and A5 is line A4A5. The included angle between lines A4A1 and A4A5 is α1.

[0065] The ratio of α1 to α2 is in the range of α1:α2≥0.25.

[0066] Specifically, points A2 and A1 are located on the same cutting plane of the ultra-depth-of-field microscope image, thus effectively ensuring that points A2 and A1 are on the same vertical plane of the conical burr. Similarly, points A4 and A1 are located on the same cutting plane of the ultra-depth-of-field microscope image, thus effectively ensuring that points A4 and A1 are on the same vertical plane of the conical burr.

[0067] Point A2 was chosen to be 0.1 mm from the tip of the burr because the line A1A2 more closely resembles the shape of a conical burr. Furthermore, being 0.1 mm from the tip of the burr is far from the flat area at the tip, making it less susceptible to the sudden flattening of the conical burr tip.

[0068] Under the above conditions, the larger the value of α1, the closer the conical burr is to the outer circumferential surface of the cylinder liner, that is, the more flat the lower middle part of the conical burr becomes. When the lower middle part of the conical burr is flatter, the contact area between the conical burr and the outer circumferential surface of the cylinder liner increases, resulting in a stronger connection between the conical burr and the outer circumferential surface of the cylinder liner and reducing the likelihood of breakage. Of course, if the value of α1 is too large, the conical burr on the cylinder liner will exhibit a large inverted cone shape. The coating at the root of the burr will not be easily removed during shot blasting, and defects such as inclusions and porosity are prone to occur at the root of the burr during die casting, leading to a decrease in the bonding rate.

[0069] Under the above conditions, α2 defines the structure of the necking position of the conical burr. When α2 is within an appropriate range, the bonding rate between a single burr and the cylinder block is high, and the bonding rate between the cylinder block and the outer surface of the cylinder liner is also high, thereby ensuring that the overall structure of the cylinder liner has excellent heat dissipation capabilities.

[0070] Furthermore, this application specifies the ratio range of α1 and α2 as follows: α1:α2≥0.25. When α1 and α2 are within the above-mentioned ratio range, the bonding rate between the cylinder liner and the cylinder block is relatively high, thereby ensuring that the overall structure of the cylinder liner has excellent heat dissipation capabilities.

[0071] 7. The burr-shaped cast-in cylinder liner provided in this application further specifies that the ratio of α1 to α2 in the conical burrs is within the range of 0.25 ≤ α1: α2 ≤ 1.0. When α1 and α2 are within the above-mentioned ratio range, it can effectively ensure a high bonding rate between each burr and the cylinder block, thereby ensuring that the overall structure of the cylinder liner has excellent heat dissipation capabilities.

[0072] 8. The burr-shaped cast-in cylinder liner provided in this application has 45 to 85 conical burrs within a 1 square centimeter area on the cylinder liner.

[0073] In this application, the number of tapered burrs within a 1 square centimeter area is 45 to 85. A suitable number of tapered burrs ensures the bonding rate between the cylinder liner's outer surface and the cylinder block. This increased bonding rate effectively guarantees the heat dissipation capacity of the overall cylinder liner structure, while simultaneously improving the bonding strength between the overall cylinder liner structure and the cylinder block.

[0074] 9. The burr-shaped cast-in cylinder liner provided in this application has 6 to 11 tapered burrs passing through any 10mm long line segment on the outer circumferential surface of the cylinder liner.

[0075] By limiting the number of tapered burrs passing through any 10mm long line segment on the outer circumference of the cylinder liner, the number and density of tapered burrs on the outer circumference of the cylinder liner can be effectively limited. Under the above parameters, a suitable tapered burr density can ensure the bonding rate between the outer surface of the cylinder liner and the cylinder block. An improved bonding rate can effectively ensure the heat dissipation capacity of the overall cylinder liner structure, while also improving the bonding strength between the overall cylinder liner structure and the cylinder block.

[0076] 10. The burr detection method for burr-like cast-in cylinder liners provided in this application includes: a method for detecting the diameter of burrs at positions 0.25 mm and 0.4 mm from their tips. Specifically, it includes the following steps:

[0077] Step S101 involves using the end position of the cylinder liner or the perpendicular cut surface in the radial direction of the cylinder liner as the detection surface. In this step, using the end position of the cylinder liner or the radial cut surface as the detection surface makes it easy to locate the detection surface. Furthermore, in this application, the specific location of the radial cut surface of the cylinder liner is not limited.

[0078] Step S102: Place the inspection surface of the cylinder liner under the objective lens of a super depth-of-field microscope; Step S103: Rotate the coarse and fine adjustment knobs until a clear image is seen on the computer screen; in this step, the image of the inspection surface is focused on using the super depth-of-field microscope. Furthermore, in selecting the specific burr to be inspected, burrs with a relatively intact longitudinal section are chosen. "Relatively intact" means the longitudinal section of the burr is formed by cutting along the longitudinal section from near the top of the burr.

[0079] Step S104: Using the image from step S103, locate the positions of the burr 0.25mm and 0.4mm from the tip of the burr, respectively, downwards along the vertical direction. The distance from the tip is selected as the highest point of the longitudinal section of the burr, and the allowable error for this distance is ±0.018mm. In this step, the positions of the selected burrs to be tested, 0.25mm and 0.4mm from the tip, are found in the image from step S103. Specifically, the vertical line drawing function of a super-depth-of-field microscope is used to find these positions. In this step, the distance from the tip is selected as the highest point of the longitudinal section of the burr, and the allowable error for this distance is ±0.018mm. This reduces the influence of human factors.

[0080] Step S105: Detect the intercept L1 value at the position 0.25mm from the top of the burr and the intercept L2 value at the position 0.4mm from the top of the burr, as described in step S104; wherein the diameters at the 0.25mm and 0.4mm positions from the top of the burr are the horizontal lengths of the longitudinal section of the burr. In this step, the horizontal length values ​​at the 0.25mm and 0.4mm positions are measured using the horizontal scribing function of a super depth-of-field microscope.

[0081] 11. The burr detection method for burr-shaped cast-in cylinder liners provided in this application, wherein the detection method for the included angles α1 and α2 of dumbbell-shaped burrs is as follows:

[0082] Step S201: Based on steps S101 to S104, locate the dumbbell-shaped burrs at positions 0.25mm and 0.4mm from the tip, respectively. In this step, the same measurement method as in steps S101 to S104 is used to locate the dumbbell-shaped burrs at positions 0.25mm and 0.4mm from the tip.

[0083] In step S202, at a position 0.25 mm from the tip of the burr in step S201, select points A1 and A3 on the outer contour of the dumbbell-shaped burr; select point A2 on the tip of the dumbbell-shaped protrusion of the dumbbell-shaped burr; wherein, point A2 is the outermost position of the dumbbell-shaped protrusion in the longitudinal section of the burr in step S103 and the ultra-depth-of-field microscope image; measure the angle α2 between the extension of line A1A3 and line A1A2 using the software angle measurement function of the ultra-depth-of-field microscope. In this step, the selection of the positions of points A1 and A3 on the outer contour of the dumbbell-shaped burr is based on the position 0.25 mm from the tip of the burr found in step S201, and then the horizontal tracing function of the ultra-depth-of-field microscope equipment is used to draw a line through the above 0.25 mm position, and the point that intersects with the outer contour of the dumbbell-shaped burr is the above-mentioned point A1 and point A3.

[0084] Furthermore, regarding the selection of point A2 in this step, the outermost position of the dumbbell-shaped protrusion in the longitudinal section of the burr in the ultra-depth-of-field microscope image is selected. The allowable error for this position selection is ±0.018mm. This reduces the influence of human factors.

[0085] 12. The burr detection method for cast-in cylinder liners provided in this application, wherein the detection method for the included angles α1 and α2 of the conical burrs is as follows:

[0086] Step S301: Based on steps S101 to S104, locate the positions of the conical burr at 0.25mm and 0.4mm from the tip, respectively. In this step, the same measurement method as in steps S101 to S104 is used to locate the positions of the conical burr at 0.25mm and 0.4mm from the tip.

[0087] In step S302, at the 0.25mm distance from the top of the burr in step S301, select points A1 and A3 on the outer contour of the conical burr. Using the ultra-depth-of-field microscope image from step S103, find the position 0.1mm from the top of the burr, moving downwards along the vertical direction. At the 0.1mm distance from the top of the burr, select point A2 on the outer contour of the longitudinal section of the burr in the ultra-depth-of-field microscope image. Measure the angle α2 between the extension of line A1A3 and line A1A2 using the angle measurement function of the ultra-depth-of-field microscope software. In this step, the selection of points A1 and A3 on the outer contour of the conical burr is based on the 0.25mm distance from the top of the burr found in step S301. Then, using the horizontal line drawing function of the ultra-depth-of-field microscope equipment, the points where the line drawn at the 0.25mm position intersects with the outer contour of the conical burr are points A1 and A3.

[0088] In addition, for the selection of the position of point A2 on the outer contour of the conical burr, based on the position of 0.1mm from the top of the burr found in step S301, the horizontal tracing function of the ultra-depth-of-field microscope equipment is used to draw a line through the above-mentioned 0.1mm position, which is close to the above-mentioned point A1 and intersects with the outer contour of the conical burr. This point is the above-mentioned point A2. Attached Figure Description

[0089] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0090] Figure 1 is a schematic diagram showing the specific parameters and locations of the longitudinal section of the dumbbell-shaped burr provided in this application;

[0091] Figure 2 is a schematic diagram showing the positions of diameters L1 and L2 on the longitudinal section of the tapered burr provided in this application;

[0092] Figure 3 is a schematic diagram showing the specific parameters of the longitudinal section of the tapered burr provided in this application;

[0093] Figure 4 is a longitudinal section sectional view of the cylinder liner provided in this application;

[0094] Figure 5 is a schematic diagram of the detection surface position at the end of the cylinder liner provided in this application;

[0095] Figure 6 is a schematic diagram of the position A of the cylinder liner outer diameter for contact rate detection provided in this application.

[0096] Explanation of reference numerals in the attached figures:

[0097] 1-Cylinder liner; 2-Outer peripheral surface; 3-Dumbbell-shaped burr; 4-Conical burr; 5-Inspection surface. Detailed Implementation

[0098] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0099] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0100] Example 1

[0101] Referring to Figures 1 and 4, Figure 1 shows a schematic diagram of the specific parameters of the longitudinal section of the dumbbell-shaped burr in an embodiment of this application; Figure 4 is a longitudinal section sectional view of the cylinder liner in an embodiment of this application.

[0102] A burr-shaped cast-in cylinder liner, as shown in Figure 5, is made of cast iron and cast into the cylinder block using a die-casting process, forming multiple burrs on the outer peripheral surface 2 of the cylinder liner 1. At least one of the burrs satisfies the following conditions:

[0103] The burr includes a necked protrusion located 0.2 mm to 0.35 mm from the tip of the burr. As shown in Figure 1, the necked protrusion is a dumbbell-shaped burr 3.

[0104] In this embodiment, the diameter of the dumbbell-shaped burr 3 at a position 0.25 mm from the tip is L1, and the diameter of the burr at a position 0.4 mm from the tip is L2. The ratio of diameter L1 to diameter L2 is in the range of 0.65 ≤ L1 : L2 ≤ 1.15. Within the above ratio range, the bonding rate between a single burr and the cylinder body is relatively high, ensuring the bonding strength between the burr and the cylinder body.

[0105] For specific experimental data, please refer to the table below:

[0106] As shown in the table above, in this preferred embodiment of the application, when the ratio of diameter L1 to diameter L2 is in the range of 0.65 ≤ L1:L2 ≤ 1, the bonding rate between the burr and the cylinder block is significantly higher than when the ratio of diameter L1 to diameter L2 is less than 0.65 or greater than 1.15. The tools used to obtain the above data are as follows: the cutting tool used for cutting the cylinder liner 1 in the radial direction is a metal circular saw, model: Dongguan Jincheng Machinery Co., Ltd., JC-130-NC. The ultra-depth-of-field microscope tool model is: Keyence Japan, VHX-2000.

[0107] Furthermore, in this embodiment, to further improve the bonding strength between the cylinder liner 1 and the cylinder block, and to ensure that the dumbbell-shaped burr 3 is firmly connected to the outer peripheral surface 2 of the cylinder liner 1 and is not prone to breakage, as shown in Figure 1:

[0108] At the diameter L1 position of the dumbbell-shaped burr 3, the outer contour of the dumbbell-shaped burr 3 has points A1 and A3, and the line connecting points A1 and A3 is the diameter L1; at the tip of the outer contour of the dumbbell-shaped protrusion position of the dumbbell-shaped burr 3, there is also a point A2; points A2 and A1 are located on the same longitudinal section of the dumbbell-shaped burr 3, the line connecting points A1 and A2 is line A1A2, the line connecting points A1 and A3 is line A1A3, and the angle between the extension of line A1A3 and line A1A2 is α2; the above α2 defines the structure of the necking position of the dumbbell-shaped burr 3.

[0109] At the diameter L2 position of the dumbbell-shaped burr 3, the outer contour of the dumbbell-shaped burr 3 has points A4 and A5, and the line connecting points A4 and A5 is the diameter L2. Points A4 and A1 are located on the same longitudinal section of the dumbbell-shaped burr 3, and the line connecting points A4 and A1 is line A4A1. The line connecting points A4 and A5 is line A4A5, and the angle between lines A4A1 and A4A5 is α1. The larger the value of α1, the closer the dumbbell-shaped burr 3 is to the outer peripheral surface 2 of the cylinder liner 1, that is, the closer the lower middle part of the dumbbell-shaped burr 3 is to being flat. When the lower middle part of the dumbbell-shaped burr 3 is closer to being flat, the connection surface between the dumbbell-shaped burr 3 and the outer peripheral surface 2 of the cylinder liner 1 is increased, and the connection between the dumbbell-shaped burr 3 and the outer peripheral surface 2 of the cylinder liner 1 is firm and not prone to breakage.

[0110] The ratio of α1 to α2 is in the range of 2.1 ≥ α1: α2 ≥ 0.5. When α1 and α2 are within the above ratio range, the bonding rate between a single burr and the cylinder block is high, the bonding strength between the cylinder liner 1 and the cylinder block is excellent, and the dumbbell-shaped burr 3 is firmly connected to the outer peripheral surface 2 of the cylinder liner 1.

[0111] For specific experimental data, please refer to the table below:

[0112] As shown in the table above, in this preferred embodiment of the application, when the ratio of the included angle α1 to the included angle α2 is in the range of 2.1 ≥ α1: α2 ≥ 0.5, the bonding rate between the burr and the cylinder block is significantly higher than when the ratio of the included angle α1 to the included angle α2 is less than 0.5 or greater than 2.1. The tools used to obtain the above data are as follows: the cutting tool used for cutting the cylinder liner 1 in the radial direction is a metal circular saw, model: Dongguan Jincheng Machinery Co., Ltd., JC-130-NC. The ultra-depth-of-field microscope tool model is: Keyence Japan, VHX-2000.

[0113] In this embodiment, a suitable number of dumbbell-shaped burrs 3 can ensure the bonding rate between the multiple burrs on the cylinder liner 1 and the cylinder block, thereby improving the bonding strength. The number of dumbbell-shaped burrs 3 on the cylinder liner 1 within a 1 square centimeter area is 30 to 80.

[0114] In this embodiment, a suitable burr density of dumbbell-shaped burrs 3 can ensure the bonding rate between multiple burrs on the cylinder liner 1 and the cylinder block, thereby improving the bonding strength. The dumbbell-shaped burrs 3 are located on any 10mm long line segment of the outer circumferential surface 2 of the cylinder liner 1, and the number of dumbbell-shaped burrs 3 passing through them is 4 to 8.

[0115] The method for detecting dumbbell-shaped burrs in cast-in cylinder liners includes:

[0116] A method for detecting the diameter of a burr at positions 0.25 mm and 0.4 mm from its tip includes the following steps:

[0117] Step S101: The end position of the cylinder liner 1, or the vertical cut surface of the cylinder liner 1 in the radial direction, is used as the detection surface 5.

[0118] Step S102: Place the inspection surface 5 of the cylinder liner 1 under the objective lens of the ultra-depth-of-field microscope;

[0119] Step S103: Rotate the coarse and fine focus knobs until a clear image is seen on the computer screen.

[0120] Step S104: Using the image from step S103, find the positions of the burr 0.25mm and 0.4mm from the top of the burr, respectively, from the top of the burr downwards and along the vertical direction; wherein, the position of the burr from the top of the burr is selected as the highest point of the longitudinal section of the burr, and the allowable error of the distance between the burr and the top of the burr is ±0.018mm.

[0121] Step S105: Detect the intercept L1 value at the position 0.25mm from the top of the burr and the intercept L2 value at the position 0.4mm from the top of the burr in step S104; wherein, the diameters at the positions 0.25mm and 0.4mm from the top of the burr are the horizontal lengths of the longitudinal section of the burr.

[0122] Furthermore, the detection method for the included angles α1 and α2 of the dumbbell-shaped burr 3 is as follows:

[0123] Step S201: According to steps S101 to S104, locate the dumbbell-shaped burr 3 at positions 0.25mm and 0.4mm from the tip, respectively;

[0124] In step S202, at a position 0.25mm from the tip of the burr in step S201, select points A1 and A3 on the outer contour of the dumbbell-shaped burr 3; select point A2 on the tip of the outer contour of the dumbbell-shaped protrusion of the dumbbell-shaped burr 3; wherein, point A2 is the outermost position of the dumbbell-shaped protrusion in the longitudinal section of the burr in step S103 and the ultra-depth-of-field microscope image, and the allowable error of the outermost position of the dumbbell-shaped protrusion is ±0.018mm; measure the angle α2 between the extension of line A1A3 and line A1A2 using the angle measurement function of the ultra-depth-of-field microscope software;

[0125] In step S201, at a distance of 0.4 mm from the top of the burr, select points A4 and A5 on the outer contour of the dumbbell-shaped burr 3; use the angle measurement function of the ultra-depth-of-field microscope software to measure the included angle α1 between the connecting lines A4A1 and A4A5.

[0126] In this embodiment, the binding rate measurement method specifically includes the following steps:

[0127] Step S1: Die-cast the cylinder liner into the cylinder body. The aluminum molten metal melting temperature is controlled within the range of 700℃ to 720℃, and the pouring temperature is controlled within the range of 650℃ to 680℃. The cylinder liner preheating temperature is controlled at 130-150℃. A 28000KN die-casting machine is used, with a slow injection speed of 0.2m / s and a fast injection speed of 5.5m / s. The final pressure is set to be maintained at 45MPa.

[0128] Step S2: Cut a ring from the top of the die-cast cylinder block 25-35mm away from the top of the cylinder liner, and cut a ring from the tail of the die-cast cylinder block 25-35mm away from the end of the cylinder liner.

[0129] Next, the annular end faces of the top and bottom of the cylinder liner are sanded with sandpaper, passing through 180-grit, 400-grit, and 800-grit wet sandpaper respectively, and polished on a polishing machine as needed.

[0130] Step S3: After grinding and polishing, inspect the bonding rate between the aluminum cylinder block and the outer diameter of the cylinder liner at the top and bottom of the cylinder liner. The specific inspection locations are as shown in Figure 6, at four 10mm circumference segments of the outer diameter of the cylinder liner at 90-degree intervals. The specific inspection method is as follows:

[0131] Step S301: Using a super depth-of-field microscope, measure the length of the porosity within a circumference of 10000μm along the burr surface; wherein, under the microscope, visual observation reveals a gap between the aluminum cylinder block and the cast iron of the cylinder liner 1, indicating that there is a pore at that location; the length of this gap is measured as the length of the pore.

[0132] Step S302: Calculate the bonding rate between the aluminum cylinder block and the cylinder liner outer diameter using the bonding rate calculation formula: Bonding rate = (100 - (∑pore length)) 2 / 100000000))%; where the length of the pores is in μm.

[0133] Of course, in this embodiment, the number of dumbbell-shaped burrs 3 on the cylinder liner 1 is not specifically limited. In other embodiments, the number of dumbbell-shaped burrs 3 on the cylinder liner 1 within a 1 square centimeter area may be less than 30 or more than 80.

[0134] Of course, in this embodiment, the ratio range of α1 and α2 is not specifically limited. In other embodiments, the ratio range of α1 and α2 can also be: α1:α2≤0.5; or, the ratio range of α1 and α2 can also be: α1:α2≥2.1.

[0135] Of course, in this embodiment, the number of dumbbell-shaped burrs 3 passing through any 10mm long line segment on the outer peripheral surface 2 of the cylinder liner 1 is not specifically limited. In other embodiments, the number of dumbbell-shaped burrs 3 passing through any 10mm long line segment on the outer peripheral surface 2 of the cylinder liner 1 can be less than 4 or more than 8.

[0136] Of course, in this embodiment, the specific method of casting the cylinder liner 1 into the cylinder block is not specifically limited. In other embodiments, the cylinder liner 1 is made of cast iron and is cast into the cylinder block by gravity casting process.

[0137] Example 2

[0138] Referring to Figures 2 and 4, Figure 2 shows a schematic diagram of the positions of diameters L1 and L2 on the longitudinal section of the conical burr in an embodiment of this application; Figure 4 is a longitudinal section sectional view of the cylinder liner in an embodiment of this application.

[0139] A burr-shaped cast-in cylinder liner, as shown in Figure 5, is made of cast iron and cast into the cylinder block using a die-casting process, forming multiple burrs on the outer peripheral surface 2 of the cylinder liner 1. At least one of the burrs satisfies the following conditions:

[0140] The burr includes a pointed, conical protrusion. The pointed, conical protrusion is a conical burr 4;

[0141] The diameter of the burr at a position 0.25 mm from the top is L1, and the diameter of the burr at a position 0.4 mm from the top is L2; ​​the ratio of diameter L1 to diameter L2 is in the range of 0.65 ≤ L1: L2 ≤ 1.15; within the above ratio range, the bonding rate between a single burr and the cylinder body is high, ensuring the bonding strength between the burr and the cylinder body.

[0142] Furthermore, in this embodiment, to further improve the bonding strength between the cylinder liner 1 and the cylinder block, and to ensure that the tapered burr 4 is firmly connected to the outer peripheral surface 2 of the cylinder liner 1 and is not prone to breakage, Figure 3 shows a schematic diagram of the specific parameters and locations of the longitudinal section of the tapered burr.

[0143] At the diameter L1 position of the conical burr 4, the outer contour of the conical burr 4 has points A1 and A3, and the line connecting points A1 and A3 is the diameter L1; the outer contour of the conical burr 4 also has point A2, which is located 0.1 mm away from the tip of the burr; points A2 and A1 are located on the same longitudinal section of the conical burr 4, the line connecting points A1 and A2 is line A1A2, the line connecting points A1 and A3 is line A1A3, and the angle between line A1A3 and line A1A2 is α2;

[0144] At the diameter L2 position of the conical burr 4, the outer contour of the conical burr 4 has points A4 and A5, and the line connecting points A4 and A5 is the diameter L2; points A4 and A1 are located on the same longitudinal section of the conical burr 4, and the line connecting points A4 and A1 is line A4A1, the line connecting points A4 and A5 is line A4A5, and the included angle between line A4A1 and line A4A5 is α1;

[0145] The ratio of α1 to α2 is in the range of 1.0 ≥ α1 : α2 ≥ 0.25.

[0146] For specific experimental data, please refer to the table below:

[0147] As shown in the table above, in this preferred embodiment of the application, when the ratio of the included angle α1 to the included angle α2 is in the range of 1.0 ≥ α1: α2 ≥ 0.25, the bonding rate between the burr and the cylinder block is significantly higher than when the ratio of the included angle α1 to the included angle α2 is less than 0.25 or greater than 1.0. The tools used to obtain the above data are as follows: the cutting tool used for cutting the cylinder liner 1 in the radial direction is a metal circular saw, model: Dongguan Jincheng Machinery Co., Ltd., JC-130-NC. The ultra-depth-of-field microscope tool model is: Keyence Japan, VHX-2000.

[0148] In this embodiment, a suitable number of tapered burrs 4 can ensure the bonding rate between the multiple burrs on the cylinder liner 1 and the cylinder block, thereby improving the bonding strength. The number of tapered burrs 4 on the cylinder liner 1 within a 1 square centimeter area is between 45 and 85.

[0149] In this embodiment, a suitable burr density of the conical burrs 4 can ensure the bonding rate between the multiple burrs on the cylinder liner 1 and the cylinder block, thereby improving the bonding strength. The surface is defined as any 10mm long line segment of the conical burrs 4 on the outer circumferential surface 2 of the cylinder liner 1, with 6 to 11 conical burrs 4 passing through it.

[0150] A method for detecting burrs in a cast-in cylinder liner, comprising:

[0151] A method for detecting the diameter of a conical burr 4 at positions 0.25 mm and 0.4 mm from its tip includes the following steps:

[0152] Step S101: The end position of the cylinder liner 1, or the vertical cut surface of the cylinder liner 1 in the radial direction, is used as the detection surface 5.

[0153] Step S102: Place the inspection surface 5 of the cylinder liner 1 under the objective lens of the ultra-depth-of-field microscope;

[0154] Step S103: Rotate the coarse and fine focus knobs until a clear image is seen on the computer screen.

[0155] Step S104: Using the image from step S103, find the positions of the burr 0.25mm and 0.4mm from the top of the burr, respectively, from the top of the burr downwards and along the vertical direction; wherein, the position of the burr from the top of the burr is selected as the highest point of the longitudinal section of the burr, and the allowable error of the distance between the burr and the top of the burr is ±0.018mm.

[0156] Step S105: Detect the intercept L1 value at the position 0.25mm from the top of the burr and the intercept L2 value at the position 0.4mm from the top of the burr in step S104; wherein, the diameters at the positions 0.25mm and 0.4mm from the top of the burr are the horizontal lengths of the longitudinal section of the burr.

[0157] The detection method for the included angles α1 and α2 of the conical burr 4 is as follows:

[0158] Step S301: Based on steps S101 to S104, locate the positions of the conical burr 4 at 0.25mm and 0.4mm from the top, respectively; Step S302: At the 0.25mm position from the top of the burr in step S301, select points A1 and A3 on the outer contour of the conical burr 4; Using the ultra-depth-of-field microscope image from step S103, locate the position of the burr at 0.1mm from the top of the burr, moving downwards along the vertical direction; At the 0.1mm position from the top of the burr, select point A2 on the outer contour of the longitudinal section of the burr in the ultra-depth-of-field microscope image; Using the angle measurement function of the ultra-depth-of-field microscope software, measure the angle α2 between the extension of line A1A3 and line A1A2;

[0159] In step S301, at a distance of 0.4 mm from the top of the burr, select points A4 and A5 on the outer contour of the conical burr 4; use the angle measurement function of the ultra-depth-of-field microscope software to measure the included angle α1 between the connecting lines A4A1 and A4A5.

[0160] In this embodiment, the binding rate measurement method specifically includes the following steps:

[0161] Step S1: Die-cast the cylinder liner into the cylinder body. The aluminum molten metal melting temperature is controlled within the range of 700℃ to 720℃, and the pouring temperature is controlled within the range of 650℃ to 680℃. The cylinder liner preheating temperature is controlled at 130-150℃. A 28000KN die-casting machine is used, with a slow injection speed of 0.2m / s and a fast injection speed of 5.5m / s. The final pressure is set to be maintained at 45MPa.

[0162] Step S2: Cut a ring from the top of the die-cast cylinder block 25-35mm away from the top of the cylinder liner, and cut a ring from the tail of the die-cast cylinder block 25-35mm away from the end of the cylinder liner.

[0163] Next, the annular end faces of the top and bottom of the cylinder liner are sanded with sandpaper, passing through 180-grit, 400-grit, and 800-grit wet sandpaper respectively, and polished on a polishing machine as needed.

[0164] Step S3: After grinding and polishing, inspect the bonding rate between the aluminum cylinder block and the outer diameter of the cylinder liner at the top and bottom of the cylinder liner. The specific inspection locations are as shown in Figure 6, at four 10mm circumference segments of the outer diameter of the cylinder liner at 90-degree intervals. The specific inspection method is as follows:

[0165] Step S301: Using a super depth-of-field microscope, measure the length of the porosity within a circumference of 10000μm along the burr surface; wherein, under the microscope, visual observation reveals a gap between the aluminum cylinder block and the cast iron of the cylinder liner 1, indicating that there is a pore at that location; the length of this gap is measured as the length of the pore.

[0166] Step S302: Calculate the bonding rate between the aluminum cylinder block and the cylinder liner outer diameter using the bonding rate calculation formula: Bonding rate = (100 - (∑pore length)) 2 / 100000000)%; where the length of the pores is in μm.

[0167] Of course, in this embodiment, the ratio range of α1 and α2 is not specifically limited. In other embodiments, the ratio range of α1 and α2 can also be: α1:α2<0.25; or α1:α2>1.0.

[0168] Of course, in this embodiment, the number of conical burrs 4 on the cylinder liner 1 is not specifically limited. In other embodiments, the number of conical burrs 4 on the cylinder liner 1 within a 1 square centimeter area may be less than 45 or more than 85.

[0169] Of course, in this embodiment, the number of tapered burrs 4 passing through any 10mm long line segment on the outer peripheral surface 2 of the cylinder liner 1 is not specifically limited. In other embodiments, the number of tapered burrs 4 passing through any 10mm long line segment on the outer peripheral surface 2 of the cylinder liner 1 can be less than 6 or more than 11.

[0170] Of course, in this embodiment, the specific method of casting the cylinder liner 1 into the cylinder block is not specifically limited. In other embodiments, the cylinder liner 1 is made of cast iron and is cast into the cylinder block by gravity casting process.

[0171] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A burr-shaped cast-in cylinder liner, the cylinder liner (1) being made of cast iron, cast into a cylinder block by a die casting or gravity casting process, a plurality of burrs being formed on an outer peripheral surface (2) of the cylinder liner (1), characterized in that, At least one of the burrs satisfies: The diameter of the burr at a position 0.25 mm from the tip is L1, and the diameter of the burr at a position 0.4 mm from the tip is L2; ​​the ratio of diameter L1 to diameter L2 is: 0.65 ≤ L1: L2 ≤ 1.

15. The burr may include a necked protrusion located 0.2 mm to 0.35 mm from the tip of the burr; or the burr may include a pointed, conical protrusion.

2. The burr-like cast-in cylinder liner according to claim 1, characterized by The protrusion, which is in the shape of a constricted neck, is a dumbbell-shaped burr (3); At the diameter L1 position of the dumbbell-shaped burr (3), the outer contour of the dumbbell-shaped burr (3) has points A1 and A3, and the line connecting points A1 and A3 is the diameter L1; at the tip of the outer contour of the dumbbell-shaped protrusion position of the dumbbell-shaped burr (3), there is also point A2; points A2 and A1 are located on the same longitudinal section of the dumbbell-shaped burr (3), the line connecting points A1 and A2 is line A1A2, the line connecting points A1 and A3 is line A1A3, and the angle between the extension of line A1A3 and line A1A2 is α2; At the diameter L2 position of the dumbbell-shaped burr (3), the outer contour of the dumbbell-shaped burr (3) has points A4 and A5, and the line connecting points A4 and A5 is the diameter L2; points A4 and A1 are located on the same longitudinal section of the dumbbell-shaped burr (3), the line connecting points A4 and A1 is line A4A1, the line connecting points A4 and A5 is line A4A5, and the included angle between line A4A1 and line A4A5 is α1; The ratio of α1 to α2 is in the range of α1:α2≥0.

5.

3. The burr-like cast-in cylinder liner according to claim 2, characterized by The ratio of α1 to α2 is in the range of α1:α2≤2.

1.

4. The burr-like cast-in cylinder liner according to claim 2 or 3, characterized by The number of dumbbell-shaped burrs (3) on the cylinder liner (1) within a 1 square centimeter area is 30 to 80.

5. The burr-like cast-in cylinder liner according to claim 2 or 3, characterized by The number of dumbbell-shaped burrs (3) passing through any 10mm long line segment on the outer peripheral surface (2) of the cylinder liner (1) is 4 to 8.

6. The burr-like cast-in cylinder liner according to claim 1, characterized by The pointed, conical protrusion is a conical burr (4); At the diameter L1 position of the conical burr (4), the outer contour of the conical burr (4) has points A1 and A3, and the line connecting points A1 and A3 is the diameter L1; the outer contour of the conical burr (4) also has point A2, which is located 0.1 mm away from the top of the burr; points A2 and A1 are located on the same longitudinal section of the conical burr (4), the line connecting points A1 and A2 is line A1A2, the line connecting points A1 and A3 is line A1A3, and the angle between line A1A3 and line A1A2 is α2; At the diameter L2 position of the conical burr (4), the outer contour of the conical burr (4) has points A4 and A5, and the line connecting points A4 and A5 is the diameter L2; points A4 and A1 are located on the same longitudinal section of the conical burr (4), the line connecting points A4 and A1 is line A4A1, the line connecting points A4 and A5 is line A4A5, and the included angle between line A4A1 and line A4A5 is α1; The ratio of α1 to α2 is in the range of α1:α2≥0.

25.

7. The burr-like cast-in cylinder liner according to claim 6, characterized by The ratio of α1 to α2 is in the range of α1:α2≤1.

0.

8. The burr-shaped cast-in cylinder liner according to claim 6 or 7, characterized in that, On the cylinder liner (1), the number of conical burrs (4) within a 1 square centimeter range is 45 to 85.

9. The burr-like cast-in cylinder liner according to claim 6 or 7, characterized by The number of tapered burrs (4) passing through any 10mm long line segment on the outer peripheral surface (2) of the cylinder liner (1) is 6 to 11.

10. A method for detecting burrs in a cast-in cylinder liner, characterized in that, include: A method for detecting the diameter of a burr at positions 0.25 mm and 0.4 mm from its tip includes the following steps: Step S101, take the end position of the cylinder liner (1) or the vertical cutting surface of the cylinder liner (1) in the radial direction as the detection surface (5); Step S102: Place the inspection surface (5) of the cylinder liner (1) under the objective lens of the ultra-depth-of-field microscope; Step S103: Rotate the coarse and fine focus knobs until a clear image is seen on the computer screen. Step S104: Using the image from step S103, find the positions of the burr 0.25mm and 0.4mm from the top of the burr, respectively, from the top of the burr downwards and along the vertical direction; wherein, the position of the burr from the top of the burr is selected as the highest point of the longitudinal section of the burr, and the allowable error of the distance between the burr and the top of the burr is ±0.018mm. Step S105: Detect the intercept L1 value at the position 0.25mm from the top of the burr and the intercept L2 value at the position 0.4mm from the top of the burr in step S104; wherein, the diameters at the positions 0.25mm and 0.4mm from the top of the burr are the horizontal lengths of the longitudinal section of the burr.

11. The burr detection method of the burr-like cast-in cylinder liner according to claim 10, characterized by The burr detection method is applied to the burr-shaped cast-in cylinder liner as described in claim 1.

12. The burr detection method of the burr-like cast-in cylinder liner according to claim 10, characterized by The burr detection method is applied to the burr-shaped cast-in cylinder liner as described in any one of claims 2 to 5; The detection method for the included angles α1 and α2 of the dumbbell-shaped burr (3) is as follows: Step S201: According to steps S101 to S104, locate the dumbbell-shaped burr (3) at positions 0.25 mm and 0.4 mm from the top, respectively; In step S202, at a position 0.25 mm from the top of the burr in step S201, select points A1 and A3 on the outer contour of the dumbbell-shaped burr (3); select point A2 on the tip of the outer contour of the dumbbell-shaped protrusion of the dumbbell-shaped burr (3); wherein, point A2 is the outermost position of the dumbbell-shaped protrusion in the longitudinal section of the burr in step S103 and the ultra-depth-of-field microscope image, and the allowable error of the outermost position of the dumbbell-shaped protrusion is ±0.018 mm; measure the angle α2 between the extension of line A1A3 and line A1A2 using the software angle measurement function of the ultra-depth-of-field microscope. In step S201, at a distance of 0.4 mm from the top of the burr, select points A4 and A5 on the outer contour of the dumbbell-shaped burr (3); measure the included angle α1 between the line A4A1 and the line A4A5 using the angle measurement function of the ultra-depth-of-field microscope software.

13. The burr detection method of the burr-like cast-in cylinder liner according to claim 10, characterized by, The burr detection method is applied to the burr-shaped cast-in cylinder liner as described in any one of claims 6 to 9; The detection method for the included angles α1 and α2 of the conical burr (4) is as follows: Step S301: According to steps S101 to S104, find the positions of the conical burr (4) 0.25mm and 0.4mm from the top respectively; In step S302, at a position 0.25 mm from the top of the burr in step S301, select points A1 and A3 on the outer contour of the conical burr (4); using the ultra-depth-of-field microscope image from step S103, find the position 0.1 mm from the top of the burr, moving downwards along the vertical direction; at the position 0.1 mm from the top of the burr, select point A2 on the outer contour of the longitudinal section of the burr in the ultra-depth-of-field microscope image; using the angle measurement function of the ultra-depth-of-field microscope software, measure the angle α2 between the extension of line A1A3 and line A1A2; In step S301, at a distance of 0.4 mm from the top of the burr, select points A4 and A5 on the outer contour of the conical burr (4); use the angle measurement function of the software of the ultra-depth-of-field microscope to measure the included angle α1 between the connecting line A4A1 and the connecting line A4A5.

14. The burr detection method of the burr-like cast-in cylinder liner according to claim 10, characterized by, The burr detection method for the burr-shaped cast-in cylinder liner is used to detect L1 and L2 of the burr-shaped cast-in cylinder liner as described in claims 1 to 11.

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