A method for detecting oil content of phosphating products

Abstract

The present invention relates to the technical field of automotive parts inspection, and particularly to a method for detecting the oil content of phosphated products, which solves the problems of poor stability and low accuracy of the existing detection methods for the oil content of phosphated cylinder liners. The method for detecting the oil content of phosphated products includes: sanding a specified area on the surface of the phosphated product, and cleaning and drying the sanded specified area to obtain a phosphated product test sample; using a surface roughness meter to sequentially measure the bearing coefficients of different depth end faces at a set spacing in the cutting depth direction in the specified area of the phosphated product test sample until the measured bearing coefficient is 100%, and then calculating the oil content of the phosphated product through Q = △X·∑(1 - tp)<supgt;2< / supgt;. The method for detecting the oil content of phosphated products provided by the present invention calculates the oil content by substituting the measured bearing coefficient into formula (1) after measuring with a surface roughness meter, eliminates the interference caused by human difference factors, and realizes the improvement of the accuracy and stability of the determination of the oil content of phosphated products.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of automobile parts detection, and in particular to a method for detecting the oil content of a phosphating product. Background Art

[0002] The cylinder liner is a separate cylindrical part, which is mostly used in diesel engines and is installed in the cylinder block hole of the diesel engine. It is fixed by the cylinder head. The piston reciprocates in the inner hole of the cylinder liner and is cooled by cooling water. The cylinder liner, piston ring and piston part always have high-speed sliding friction, which can easily cause serious wear of the cylinder liner and piston assembly and cause cylinder scuffing failure. Therefore, in order to increase the life of the cylinder liner and piston assembly and improve the running-in performance, in addition to developing wear-resistant materials, proper surface treatment of the inner wall of the cylinder liner is also a feasible and important way for the cylinder.

[0003] At present, chrome plating, surface quenching (rolling quenching, laser quenching, etc.), gas soft amination, spraying, electrolytic sulfurization and phosphating treatment have been developed and applied. Among them, phosphating the inner wall of the cylinder liner can not only improve the friction state between the cylinder liner and the piston, but also improve the absorption performance of the inner wall of the cylinder liner to the lubricant. However, after the engine cylinder liner is phosphated, the oil content on the surface of the phosphating layer needs to be tested to ensure that there is a certain oil film inside the cylinder liner after the engine is shut down, thereby reducing the risk of engine damage after restarting.

[0004] However, the existing method for detecting the oil content of phosphated cylinder liners is mainly to apply 10W-40CD engine oil three times on the inner surface of the cylinder liner and let it stand for 24 hours, and then measure the weight of the cylinder liner before and after applying the engine oil to obtain the oil content value. Due to the obvious human differences between different inspectors in the preliminary preparation and measurement process, the detection value is unstable. Summary of the invention

[0005] The purpose of the embodiments of the present application is to provide a method for detecting the oil content of a phosphating product, which solves the problem of unstable detection values ​​in the existing method for detecting the oil content of a phosphating cylinder liner.

[0006] The technical solution for achieving the purpose of the present invention is as follows:

[0007] A method for detecting the oil content of a phosphating product comprises the following steps:

[0008] Sanding a specified area on the surface of the phosphating product, and cleaning and drying the sanded specified area to obtain a phosphating product test sample;

[0009] The surface roughness meter is used to measure the load factors of the end faces at different depths in the specified area of ​​the phosphating product sample in the direction of the cutting depth according to the set interval until the measured load factor is 100%, and then the oil content of the phosphating product is calculated by formula (1):

[0010] Q=△X·∑(1-tp) 2 (1)

[0011] In formula (1), Q-oil content / cm 3 ; △X-cutting distance / um; tp-bearing coefficient / %.

[0012] In some possible preferred implementations of the embodiments of the present application, sanding a specified area on the surface of the phosphating product includes:

[0013] Treating the surface of the specified area of ​​the phosphating product with concentrated sulfuric acid for 1-2 minutes, removing the concentrated sulfuric acid adhering to the surface of the specified area, and then washing the specified area and the surrounding surface with distilled water and drying;

[0014] The water-abrasive sandpaper with a particle size of 800 Cw is fixed on the grinding block, and then the grinding block is used to make a reciprocating motion to sand the surface of a specified area of ​​the phosphating product, wherein the reciprocating times of the grinding block is 3×100 times.

[0015] In a preferred implementation of the embodiment of the present application, the material of the grinding block is a non-metallic wear-resistant material.

[0016] In a preferred implementation manner of the embodiment of the present application, the material of the sand grains in the water-abrasive sandpaper is a wear-resistant material having a hardness greater than that of the phosphating product.

[0017] In a preferred implementation of the embodiment of the present application, the reciprocating motion stroke of the grinding block is 20 mm.

[0018] In a preferred implementation manner of the embodiment of the present application, the set spacing is any one of 1 μm, 2 μm, and 3 μm.

[0019] In a preferred implementation manner of the embodiment of the present application, the distance between the specified area of ​​the sample surface of the phosphating product and the bottom edge of the phosphating product is 30-40 mm.

[0020] In a preferred implementation manner of the embodiment of the present application, the bottom area of ​​the grinding block is smaller than the area of ​​a specified area of ​​the sample surface of the phosphating product.

[0021] In a preferred implementation of the embodiment of the present application, the length of the specified area on the surface of the phosphating product sample is 25 mm and the width is 55 mm.

[0022] In a preferred implementation of the embodiment of the present application, the method for detecting the oil content of the phosphating product is applied to detecting the oil content of the phosphating cylinder liner.

[0023] Compared with the prior art, the advantages or beneficial effects of the embodiments of the present application include at least:

[0024] The method for detecting the oil content of the phosphating product provided in the embodiment of the present application is to sand, clean and dry the specified area on the surface of the phosphating product, and then use a surface roughness meter to sequentially measure the load factor of each end face at each depth in the specified area according to the set spacing in the direction of the cutting depth until the measured load factor is 100%, and then use the load factor and the set spacing as parameters to calculate the oil content of the phosphating product by formula (1). In view of this, the present invention creatively proposes a method for calculating the oil content, and determines the load factor by a surface roughness meter during the detection process, eliminating the interference caused by human differences, thereby achieving the improvement of the detection value stability of the oil content of the phosphating product. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 A flow chart of a method for detecting the oil content of a phosphating product provided in an embodiment of the present application;

[0027] Figure 2 A schematic diagram of the structure of a sanding tool provided in an embodiment of the present application;

[0028] Figure 3 A three-dimensional diagram of a sanding tool grinding head provided in an embodiment of the present application;

[0029] Figure 4 A schematic diagram of a partial top view of a sanding tool provided in an embodiment of the present application;

[0030] Figure 5 A schematic structural diagram of water-abrasive sandpaper, a sanding tool provided in an embodiment of the present application.

[0031] Figure numerals: 1- sanding head; 11- sanding block; 2- connecting rod; 21- first connecting rod; 22- telescopic rod; 23- second connecting rod; 3- cylinder; 4- cylinder sleeve; 5- fixed seat; 6- water-abrasive sandpaper; 61- anti-clogging layer; 62- sanding layer; 63- first double-sided adhesive layer; 64- waterproof layer; 65- second double-sided adhesive layer; 66- toughness layer; 67- third double-sided adhesive layer. DETAILED DESCRIPTION

[0032] The following will be combined with the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described below are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0033] In order to solve the problems of poor detection result stability and low accuracy in the existing method for detecting the oil content of phosphating cylinder liners, this embodiment provides a method for detecting the oil content of phosphating products.

[0034] like Figure 1 As shown, the method for detecting the oil content of the phosphating product includes steps S101-S102.

[0035] S101: sanding a specified area on the surface of the phosphating product, and cleaning and drying the sanded specified area to obtain a phosphating product test sample.

[0036] In conjunction with step S101, those skilled in the art should understand that the phosphating product refers to a metal workpiece with a phosphating film attached to the surface, specifically a metal substrate immersed in a phosphating solution (a solution mainly composed of certain acid phosphates) for chemical treatment, and a layer of crystalline phosphate conversion film that is insoluble in water is deposited on its surface, such as phosphating gears, phosphating clutch plates, phosphating piston rings, phosphating compressors, and phosphating engine cylinder liners. There are many advantages after the metal substrate is phosphated, such as forming a phosphate protective film on the surface of the metal substrate to prevent the metal substrate from being corroded; it can also be used for primer before painting to improve the adhesion and anti-corrosion ability of the paint film layer, and it can be used in the metal cold preparation process to play a lubricating role. The embodiment of the present application takes the engine cylinder liner as an example to illustrate that by phosphating the inner wall of the cylinder liner, not only the friction state between the cylinder liner and the piston can be improved, but also the absorption performance of the inner wall of the cylinder liner to the lubricant can be improved.

[0037] In conjunction with step S101, those skilled in the art should understand that the specified area on the surface of the phosphating product refers to a sample area selected on the surface of the phosphating product. The phosphating film formed on the surface of the phosphating product is usually evenly distributed. By measuring the oil content in a sample area of ​​a known area, the oil content of the entire surface of the phosphating product can be calculated. Therefore, it is critical to select a sample area on the surface of the phosphating product for measurement. The embodiment of the present application performs steps such as sanding, cleaning, and measurement on the specified area on the surface of the phosphating product, which not only reduces the workload of measuring the oil content on the surface of the phosphating product, but also can obtain accurate oil content. Among them, the specified area is a randomly selected area on the surface of the phosphating product, and the area of ​​the specified area can be selected according to demand, and the embodiment of the present application does not make specific limitations.

[0038] In combination with step S101, in order to clean / etch and remove the phosphate film on the surface of the specified area, and to facilitate sanding to remove the rough tips of the phosphate layer, reveal the basic structure of the surface of the phosphated product that has been pickled and phosphated, and prevent the residual pickling liquid from affecting the water-abrasive sandpaper, the sanding of the specified area on the surface of the phosphated product described in the embodiment of the present application includes steps S1011-S1012.

[0039] S1011: After taking a certain area on the surface of the phosphating product, treat the specified area with concentrated sulfuric acid of 98% by mass for 1-2 minutes, then use a cotton ball to absorb the concentrated sulfuric acid attached to the surface of the specified area, and spray distilled water on the surface of the specified area to clean the specified area and the surrounding surface to remove residual substances, and finally use a cotton ball to absorb the distilled water remaining on the surface of the specified area. It should be noted that when treating the specified area with concentrated sulfuric acid, rubber gloves should be worn to prevent burns.

[0040] S1012: Use double-sided tape to fix the water-abrasive paper with a particle size of 800Cw on the grinding block, and then use the grinding block to make reciprocating motion to sand the surface of the specified area after the concentrated sulfuric acid treatment. The number of reciprocating times of the grinding block is 3×100 times. It should be noted that, in this embodiment, by fixing the water-abrasive paper with a particle size of 800Cw on the grinding block, and then using the grinding block to make reciprocating motion 3×100 times to sand the surface of the specified area, not only can the sanding degree of the surface of the specified area be achieved to the best, but also data recording is convenient. Specifically, the sand particle size of the water-abrasive paper is selected to be 800Cw, and the sanding area and sanding degree of the 800Cw water-abrasive paper are fixed. The wear amount of the water-abrasive paper is the same for each reciprocating motion. The embodiment of the present application uses 800Cw water-abrasive paper and combines 3×100 reciprocating motions for sanding, and the sanding degree is the best. At the same time, due to the surface structure design of the water-abrasive sandpaper, the grinding effect of the water-abrasive sandpaper begins to decline greatly after sanding about 100 times, affecting the sanding effect, so it is necessary to replace the water-abrasive sandpaper in time after a certain number of sandings. When replacing the water-abrasive sandpaper, it is generally necessary to stop sanding. The number of sandings of 100 times is convenient for recording. Therefore, the embodiment of the present application selects 800Cw water-abrasive sandpaper and replaces the water-abrasive sandpaper after every 100 round trips. In addition, the technology in this field needs to pay attention to that before replacing the water-abrasive sandpaper for sanding again, the sanding part should be cleaned with distilled water to remove the residual sand particles, and the surface of the grinding block should be adapted to the radius of curvature of the grinding block to ensure that the surface of the water-abrasive sandpaper is evenly stressed.

[0041] Based on the method of sanding the specified area on the surface of the phosphating product, the embodiment of the present application also provides a sanding tool to facilitate technicians in the field to better sand the specified area on the surface of the phosphating product. Figure 2 A specific structure of the sanding tool described in this embodiment is shown; Figure 3 A three-dimensional view of a grinding head of a sanding tool according to an embodiment is shown; Figure 4 A schematic top view of a connection of a portion of the sanding tool described in the embodiment is shown.

[0042] See also Figures 2 to 4 The sanding tool comprises a grinding head 1, a grinding block 11, a connecting rod 2 and a telescopic driving device; the grinding head 1 is formed by radially tangently forming a plane on the side of a cylindrical structure, and a grinding block 11 is provided on an end face of the plane formed by the tangently forming side of the grinding head 1, and the grinding block 11 is used to fix the water-abrasive sandpaper 6; one end of the grinding head 1 is connected to a first connecting rod 21 through a connecting rod 2, the first connecting rod 21 is connected to a telescopic rod 22, the telescopic rod 22 has an angle with the first connecting rod 21, the telescopic rod 22 is also connected to a second connecting rod 23, the direction of the second connecting rod 23 is the same as the movement direction of the first connecting rod 21 and its grinding head 1, and one end of the second connecting rod 23 is connected to the telescopic driving device.

[0043] It should be noted that the telescopic drive device can be realized by a cylinder or other devices capable of realizing telescopic movement back and forth; the telescopic rod 22 can also be replaced by a cylinder, as long as the telescopic function can be realized. The cylinder and the telescopic rod 22 in this embodiment are connected to the control system, and the entire working process is controlled by the control system. In addition, in order to ensure that the surface of the water-abrasive paper 6 fixed on the grinding block 11 is uniformly stressed, and the water-abrasive paper 6 only bears the weight of the grinding block 11, there shall be no other component forces increased by mechanical movement to increase or decrease the pressure of the grinding head 1.

[0044] Based on the above description, it can be known that when the sanding tool is applied to a cylinder liner, the grinding head 1 is controlled by a telescopic drive device to reciprocate in the cylinder liner sleeve to sand the specified area on the surface of the phosphating product. Specifically, when the grinding block 11 does not contact the inner wall of the cylinder liner, the telescopic rod 22 is controlled to extend so that the grinding block 11 fits tightly against the inner wall of the cylinder liner; when the grinding block 11 just fits the sanding area specified on the inner wall of the cylinder liner, sanding can be started, so that the specified area of ​​the inner wall of the cylinder liner is sanded by the cylinder liner continuously telescoping back and forth. At the same time, this embodiment controls the entire working process through a control system, realizing automatic control of sanding, and in the entire working process, the movement directions of the first connecting rod 21, the second connecting rod 23 and the grinding head 1 are kept the same, and the telescopic stroke is consistent, so as to ensure uniform force during the actual sanding process.

[0045] In combination with the sanding tool, in this embodiment, the center of the grinding block 11 is preferably perpendicular to the direction of the inner wall of the cylinder liner 4 at the sanding position, which is the same as the extension direction of the telescopic rod 22, so that before the sanding block 11 sands the inner wall of the cylinder liner 4, the telescopic rod 22 is extended so that the sanding block 11 is just aligned with the area to be sanded, thereby achieving precise sanding.

[0046] Based on the method of sanding a specified area on the surface of a phosphating product, this embodiment also provides a water-abrasive sandpaper. Figure 5 A specific structure of the water-abrasive sandpaper described in this embodiment is shown.

[0047] like Figure 5 As shown, the water-abrasive sandpaper includes, from top to bottom, an anti-clogging layer 61 , a sanding layer 62 , a first double-sided adhesive layer 63 , a waterproof layer 64 , a second double-sided adhesive layer 65 , a toughness layer 66 and a third double-sided adhesive layer 67 .

[0048] It should be noted that the sanding layer 62 is convenient for removing the rough tip of the phosphating layer, the first double-sided adhesive layer 63 is used to bond the sanding layer 62 to the waterproof layer 64, the waterproof layer 64 improves the water resistance of the water-resistant sandpaper 6, and the anti-clogging layer 61 located above the sanding layer 62 can effectively prevent the gray powder after grinding from blocking the gaps between the abrasives, thereby increasing the service life of the water-resistant sandpaper 6; and the anti-clogging layer 61 can be synthesized from 80% of carrier rubber, 15% of silicon nitride, and 5% of flake graphite material, the carrier rubber is polyurethane rubber, because the flake graphite material is a natural fixed body lubricating material with good toughness, and silicon nitride has strong high pressure creep resistance and thermal expansion resistance. The coefficient is small, and silicon nitride and flake graphite materials are added after the polyurethane rubber is melted at high temperature. The overall anti-clogging layer 61 has good density. At the same time, due to the effects of flake graphite materials and silicon nitride materials, the sliding resistance between the friction surfaces is reduced and the smoothness of the friction surfaces is increased; while the thermal expansion coefficient is small, the deformation caused by friction heat is reduced, and the service life of the water sandpaper 6 is increased; in addition, the waterproof layer 64 is also bonded with a toughness layer 66 through a second double-sided adhesive layer 65. The toughness layer 66 can be made of graphene material. Since the water sandpaper 6 is arc-shaped and needs to cooperate with the arc-shaped surface of the sanding block 11, it is not easy to be damaged and needs to have a certain toughness.

[0049] In this embodiment, the reciprocating stroke of the grinding block is controlled to be 20 mm, so as to save sanding workload and achieve better sanding effect. Specifically, when a 20 mm measuring surface is formed by sanding, the quality of the cylinder liner will not be affected. After the specified measuring area is sanded, the phosphating coating does not need to be re-plated, and the cylinder liner can still be used normally; otherwise, the quality of the cylinder liner will be affected during long-distance sanding.

[0050] In this embodiment, in order to facilitate the sanding treatment of the specified area on the surface of the phosphating product, the distance between the specified area on the surface of the phosphating product sample and the bottom edge of the phosphating product is 30-40mm. Specifically, in this embodiment, the specified area is selected at a position 30-40mm away from the bottom edge of the phosphating product. The grinding block can not only fit the surface of the specified area completely and tightly during the reciprocating motion to ensure a more uniform sanding effect, but also reduce the risk of contaminating other parts when using concentrated sulfuric acid to clean / corrode the surface of the specified area. In addition, when the cylinder liner and the piston are in motion, the piston ring on the piston and the cylinder liner move relative to each other, and 30-40mm is the starting position range of the piston ring movement.

[0051] In the present embodiment, the material of the grinding block 11 is a non-metallic wear-resistant material, so as to facilitate the fixation of the water-abrasive sandpaper on the surface of the grinding block 11 and reduce the risk of the water-abrasive sandpaper falling off the surface of the grinding block 11. Specifically, the grinding block 11 reciprocates in the cylinder sleeve. Since multiple reciprocating motions may cause wear on the surface of the grinding block 11, thereby affecting the subsequent sanding effect, the material of the grinding block 11 should have good wear resistance. Moreover, the present embodiment uses adhesive materials (such as double-sided tape, etc.) to fix the water-abrasive sandpaper, so the material of the grinding block 11 needs to have good adhesion. Therefore, based on the wear resistance and adhesion requirements of the material of the grinding block 11, the material of the grinding block in the present embodiment is preferably a non-metallic wear-resistant material, such as silicon carbide, polyurethane, etc.

[0052] In this embodiment, the material of the sand grains in the water-abrasive sandpaper 6 is a wear-resistant material with a hardness greater than that of the phosphated product, so as to facilitate a better sanding effect when the surface of the phosphated product is sanded using the water-abrasive sandpaper 6. Specifically, when the surface of the phosphated product is sanded using the water-abrasive sandpaper 6, the sand grains in the water-abrasive sandpaper 6 are in direct contact with the surface of the phosphated product, and sanding is performed as the water-abrasive sandpaper 6 reciprocates. If the hardness of the sand grains in the water-abrasive sandpaper 6 is much smaller than that of the phosphated product, it is easy to cause a poor sanding effect and it is not easy to meet the sanding requirements.

[0053] In this embodiment, the bottom area of ​​the grinding block 11 is smaller than the area of ​​the specified area of ​​the sample surface of the phosphating product to prevent the wear of other areas of the sample surface of the phosphating product. Specifically, the water-abrasive paper 6 is fixed to the bottom surface of the grinding block 11, and as the grinding block 11 reciprocates in the cylinder sleeve, when the bottom area of ​​the grinding block 11 is too large, it is necessary to fix a larger area of ​​water-abrasive paper 6. If the area of ​​the water-abrasive paper 6 is larger than the specified area, the grinding block 11 will sand other areas during the reciprocating motion, which may affect the final test result. Therefore, it is preferred that the bottom area of ​​the grinding block 11 is smaller than the area of ​​the specified area of ​​the sample surface of the phosphating product.

[0054] In this embodiment, the length of the specified area of ​​the phosphating product sample surface is preferably 25 mm and the width is 55 mm. Since the surface specification of the grinding block 11 is 20 mm×40 mm and the weight of the grinding block 11 is 3 kg, the specified area is selected to be 25 mm in length and 55 mm in width, which is just slightly larger than the surface size of the grinding block. Therefore, when sanding in the set sanding area, it will not affect the area outside the set sanding area, avoiding the influence on other areas of the cylinder liner 4. At the same time, since the weight of the grinding block 11 is 3 kg, when sanding, the sanding area only bears the weight of the grinding block 11, and the force on the grinding block 11 is not too small or too large, and the sanding is uniform and effective.

[0055] S102: Using a surface roughness meter, the load-bearing coefficients of the end faces at different depths are measured in sequence in the direction of the cutting depth at a set interval in the specified area of ​​the phosphating product sample, until the measured load-bearing coefficient is 100%, and then the oil content of the phosphating product is calculated by formula (1):

[0056] Q=△X·∑(1-tp) 2 (1)

[0057] In formula (I), Q-oil content / cm 3 ; △X-cutting distance / um; tp-bearing coefficient / %.

[0058] It should be noted that the oil content Q has two meanings: one is the thickness of the oil film in the pore volume, and its unit is μm, which is consistent with the cutting spacing △X; the other is the volume (volume) corroded on the surface, for each square meter (m 2 ) The oil content on the surface, in cm 3 Therefore, the relationship between the units of the two meanings is: 1μm=1cm 3 / m 2 .

[0059] Combined with step S102, the surface roughness meter is a tool commonly used in the art to measure the surface roughness of workpieces, such as the Marr M400 roughness meter. However, it should be noted that the model is not specifically limited in this embodiment. The working principle and use method of the surface roughness meter are as follows: the sensor is placed on the measured surface of the phosphating product sample, and the sensor is driven by the driving mechanism inside the instrument to slide along the measured surface at a constant speed. The sensor senses the roughness of the measured surface through the built-in sharp stylus. At this time, the roughness of the measured surface of the phosphating product sample causes the stylus to be displaced. The displacement changes the inductance of the sensor inductor coil, thereby generating an analog signal proportional to the roughness of the measured surface at the output end of the phase-sensitive rectifier. After amplification and level conversion, the signal enters the data acquisition system, and the measured value can be directly read, which greatly eliminates interference from human factors.

[0060] Combined with step S102, the set spacing is any one of 1μm, 2μm, and 3μm, so that more than two groups of load-bearing coefficients can be read, which is convenient for eliminating possible abnormal measurements. Specifically, since the present embodiment uses a surface roughness meter to read the load-bearing coefficients of the end faces with the same cutting spacing, if the spacing is set too large, the number of load-bearing coefficients read will be reduced, and even only one group of data may be read, which is likely to cause the read values ​​to be inaccurate or even abnormal; if the spacing is set too small, it will increase the difficulty of reading the values. Therefore, the present embodiment chooses to set the spacing to any one of 1μm, 2μm, and 3μm, and more preferably sets the spacing to 2μm.

[0061] From the above description, it can be seen that the detection method of the oil content of the phosphating product provided in this embodiment is to sand, clean and dry the specified area on the surface of the phosphating product, and then use a surface roughness meter to measure the load-bearing coefficients of the end faces of different depths in the specified area in the direction of the cutting depth according to the set spacing until the measured load-bearing coefficient is 100%, and then use the measured load-bearing coefficient and the set spacing as parameters to calculate the oil content of the phosphating product by formula (1). In view of this, the present invention creatively proposes a method for calculating the oil content, and measures the load-bearing coefficient by a surface roughness meter during the detection process, eliminating the interference caused by human differences, thereby achieving the improvement of the accuracy and stability of the determination of the oil content of the phosphating product.

[0062] The technical solution of the present invention will be further described below in conjunction with specific embodiments.

[0063] Example 1

[0064] This embodiment 1 provides a method for detecting the oil content of a phosphating cylinder protective sleeve, comprising the following steps:

[0065] Step 1: Prepare the phosphating cylinder protective sleeve test sample

[0066] A specified area with a length of 25 mm and a width of 55 mm is selected on the surface of the phosphating cylinder protective sleeve, and then the specified area is treated with concentrated sulfuric acid with a mass fraction of 98% for 1-2 minutes, and the concentrated sulfuric acid attached to the surface of the specified area is absorbed by a cotton ball, and then distilled water is sprayed on the surface of the specified area to clean the specified area and the surrounding surface to remove residual substances, and finally the distilled water remaining on the surface of the specified area is absorbed by a cotton ball.

[0067] Double-sided tape is used to fix water-grinding sandpaper with a particle size of 800Cw on the grinding block 11, and the grinding block 11 is fixed on the grinding head 1 of the sanding tool. Then, the grinding head 1 is controlled by the telescopic drive device to reciprocate 3×100 times in the cylinder sleeve sleeve to sand the specified area on the surface of the phosphating product to obtain the phosphating cylinder protective sleeve test sample.

[0068] Step 2: Determine the oil content of the phosphating cylinder protective sleeve sample

[0069] The Mahr M400 roughness tester is used to measure the load factor of each end face at each depth in the specified area of ​​the phosphating product sample in accordance with the measurement length of 5 mm and the setting interval of 2 μm in the cutting depth direction until the measured load factor is 100%. Then the oil content of the phosphating product is calculated by formula (1):

[0070] Q=△X·∑(1-tp) 2 (1)

[0071] In formula (1), Q-oil content / cm 3 ; △X-cutting spacing / μm; tp-load factor / %.

[0072] The load-bearing coefficient and the corresponding depth measured in this embodiment 1 are shown in the table.

[0073] Table 1 - Load factor at various cutting depths

[0074] Cutting depth / (um) tp / 100% 0 7 2 62 4 92 6 100

[0075] Calculate Σ(1-tp) using the values ​​obtained in Table 1 2 , the results are shown in Table 2.

[0076] Table 2-Σ(1-tp) 2 Calculation process and results

[0077]

[0078]

[0079] △X=2

[0080] The oil content is calculated by formula (1):

[0081] Q=△X·∑(1-tp) 2

[0082] =2×0.1508

[0083] =0.3016μm

[0084] That is, the cylinder liner per square meter (m 2 ) The oil volume on the surface is 0.3016 cm 3 .

[0085] The density of 10W-40CD engine oil in this embodiment is 0.81 g / cm 3 Therefore, the oil content of the cylinder liner detected in this embodiment is 0.24g.

[0086] In order to verify the oil content detected in this example, this example provides Comparative Example 1, which measures the oil content by weighing method.

[0087] Comparative Example 1 comprises the following steps:

[0088] Step 1: Prepare the phosphating cylinder protective sleeve test sample

[0089] A specified area with a length of 25 mm and a width of 55 mm is selected on the surface of the phosphating cylinder protective sleeve, and then the specified area is treated with concentrated sulfuric acid with a mass fraction of 98% for 1-2 minutes, and the concentrated sulfuric acid attached to the surface of the specified area is absorbed by a cotton ball, and then distilled water is sprayed on the surface of the specified area to clean the specified area and the surrounding surface to remove residual substances, and finally the distilled water remaining on the surface of the specified area is absorbed by a cotton ball.

[0090] Double-sided tape is used to fix water-grinding sandpaper with a particle size of 800Cw on the grinding block 11, and the grinding block 11 is fixed on the grinding head 1 of the sanding tool. Then, the grinding head 1 is controlled by the telescopic drive device to reciprocate 3×100 times in the cylinder sleeve sleeve to sand the specified area on the surface of the phosphating product to obtain the phosphating cylinder protective sleeve test sample.

[0091] Step 2: Determine the oil content of the phosphating cylinder protective sleeve sample

[0092] 1) Use a cleaning agent to clean the phosphating cylinder protective sleeve test sample. After the inner and outer surfaces are free of rust, oil stains and impurities, dry them and weigh them for recording;

[0093] 2) Place the phosphating cylinder protective sleeve sample on a gauze with an oil pan, and use a brush to apply 10W-40CD engine oil three times on its surface, and let it stand for 24 hours.

[0094] 3) Wipe off excess oil on the lower edge of the cylinder liner where it contacts the gauze, then weigh and record the weight.

[0095] 4) Calculate the oil content using formula (2): Q = BA

[0096] In formula (2): Q—oil content, g

[0097] A—weight of the phosphating cylinder protective sleeve after cleaning, g

[0098] B—weight of phosphating cylinder protective sleeve sample after oiling and standing, g

[0099] Each phosphating cylinder protective sleeve sample is measured 3 times before and after cleaning to obtain 3 sets of values. The average value is substituted into the above formula to obtain the oil content Q value.

[0100] Weighing results: The weight of the phosphating cylinder protective cover sample after cleaning is A = 13430.1g; the weight of the phosphating cylinder protective cover sample after oiling and standing is B = 13430.36g;

[0101] Measurement results: Substitute the weighed value into the formula Q=BA=13430.36-13430.1g=0.26g.

[0102] That is, the oil content of the cylinder liner detected in this comparative example is 0.26g.

[0103] By comparing Example 1 with Comparative Example 1, it can be seen that the oil content detected in Example 1 is close to the value detected in Comparative Example 1. At the same time, the oil content of the cylinder liner is 0.2-1.2 g / cm 3 , the volume of the inner surface of the cylinder liner is 0.41 cm 3 , that is, the qualified value of the oil content of the cylinder liner is 0.08-0.49g, and the oil content of the cylinder liner detected in this embodiment meets the qualified value of the oil content of the cylinder liner. Therefore, the detection method of the oil content of the phosphating product provided by the present invention can be applied to the determination of the oil content of the phosphating cylinder liner, and the interference of human factors is avoided in the whole determination process, and the determination result is stable and accurate.

[0104] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

Claims

1. A method for detecting the oil content of phosphating products, It is characterized in that The following steps are involved: Sanding a specified area on the surface of the phosphating product, and cleaning and drying the sanded specified area to obtain a phosphating product test sample; Using a surface roughness meter, the load-bearing coefficients of the end faces at different depths are measured in the specified area of ​​the phosphating product sample in the direction of the cutting depth according to the set interval until the measured load-bearing coefficient is 100%, and then the oil content of the phosphating product is calculated by formula (1): Q=△X·∑(1-tp)2 (1) In formula (1), Q-oil content / cm3; △X-cutting spacing / μm; tp-load factor / %; The sanding of the specified area on the surface of the phosphating product includes: Treating the surface of the specified area of ​​the phosphating product with concentrated sulfuric acid for 1-2 minutes, removing the concentrated sulfuric acid adhering to the surface of the specified area, and then washing the specified area and the surrounding surface with distilled water and drying; Fixing water-grinding sandpaper with a particle size of 800 Cw on a grinding block, and then using the grinding block to reciprocate to sand the surface of a specified area of ​​the phosphating product, wherein the number of reciprocating times of the grinding block is 3×100 times; The sanding tool comprises a grinding head (1), a grinding block (11), a connecting rod (2) and a telescopic driving device; the grinding head (1) is formed by radially tangently forming a plane on the side of a cylindrical structure; an end surface of the plane formed by tangently forming the side of the grinding head (1) is provided with a grinding block (11); the grinding block (11) is used to fix water-based sandpaper (6); one end of the grinding head (1) is connected to a first connecting rod (21) through a connecting rod (2); the first connecting rod (21) is connected to a telescopic rod (22); the telescopic rod (22) and the first connecting rod (21) have an angle; the telescopic rod (22) is also connected to a second connecting rod (23); the direction of the second connecting rod (23) is the same as the movement direction of the first connecting rod (21) and the grinding head (1); and one end of the second connecting rod (23) is connected to the telescopic driving device.

2. The method for detecting the oil content of the phosphating product according to claim 1, It is characterized in that The material of the grinding block is non-metallic wear-resistant material.

3. The method for detecting the oil content of the phosphating product according to claim 1, It is characterized in that The material of the sand grains in the water-abrasive sandpaper is a wear-resistant material with a hardness greater than that of the phosphating product.

4. The method for detecting the oil content of the phosphating product according to claim 1, It is characterized in that The reciprocating stroke of the grinding block is 20 mm.

5. The method for detecting the oil content of the phosphating product according to claim 1, It is characterized in that The set spacing is any one of 1 μm, 2 μm, and 3 μm.

6. The method for detecting the oil content of the phosphating product according to claim 1, It is characterized in that The distance between the specified area on the sample surface of the phosphating product and the bottom edge of the phosphating product is 30-40 mm.

7. The method for detecting the oil content of the phosphating product according to claim 6, It is characterized in that The bottom area of ​​the grinding block is smaller than the area of ​​a specified area on the surface of the phosphating product sample.

8. The method for detecting the oil content of the phosphating product according to claim 7, It is characterized in that The length of the specified area on the surface of the phosphating product sample is 25 mm and the width is 55 mm.

9. Application of the method for detecting the oil content of a phosphating product according to any one of claims 1 to 8 in detecting the oil content of a phosphating cylinder liner.

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