Impregnating agent for impregnated grinding wheel, impregnated grinding wheel for full-range profiling turnout polishing car and preparation method and application thereof

Abstract

This invention discloses an impregnating agent for impregnating grinding wheels, an impregnating grinding wheel for a full-range contour turnout grinding vehicle, its preparation method, and its application. The impregnating grinding wheel includes an impregnating grinding body, which comprises a grinding body and a permeation layer permeating within the pores of the grinding body. The grinding body is composed of abrasive, a binder, and pores formed after the abrasive and binder are pressed together. The permeation layer is formed by impregnating the grinding body with the impregnating agent. Using the above-mentioned impregnating grinding wheel to grind rails can meet the high-load grinding requirements of rails, is compatible with the grinding methods of a full-range contour turnout grinding vehicle, and can achieve comprehensive coverage of complex-shaped areas such as guard rails, switch rails, and fork points, while also accommodating mainline grinding. The surface roughness of the ground rail is reduced, resulting in better rail surface quality, excellent heat dissipation performance, extended rail service life, and reduced railway maintenance costs.

Description

Technical Field

[0001] This invention relates to the fields of abrasive manufacturing and track maintenance technology. Specifically, it relates to an impregnating agent for impregnating grinding wheels, an impregnating grinding wheel for a full-range conformal turnout grinding vehicle, and their preparation methods and applications. Background Technology

[0002] After a period of use, railway rails develop problems such as rolling fatigue, corrugation, cracks, edge thickening, and abrasions. These rail defects alter the wheel-rail contact state, creating serious safety hazards. Rail grinding is the most effective method in railway maintenance, involving grinding the rail surface to remove defects, restore the rail profile, and eliminate safety hazards. Currently, in special areas such as guard rails, switch rails, and fork points, traditional end-face grinding methods are limited, relying solely on manual labor and small machines for auxiliary grinding in restricted areas. This results in high labor intensity, difficulty in quality control, and poor operational safety. In response, a new type of full-range contour-following turnout grinding vehicle has been developed in China. This grinding vehicle adopts a three-dimensional contour-following grinding concept, breaking through the bottleneck of active contour grinding technology and achieving full coverage of mechanized turnout grinding while also maintaining the mainline rails. As a grinding wheel used in conjunction with a full-range contour turnout grinding machine, besides needing to meet different grinding speeds (2-16 km / h), the technical challenge lies in the complex structure of the turnout, which results in different rail cross-sectional shapes in different parts. The contact area between the grinding wheel and the rail is constantly changing, requiring the wheel to quickly conform to the rail surface. Under the same grinding pressure, different contact areas result in different pressures per unit area. When the contact area is small and the grinding speed is very low, heat accumulation can easily occur, leading to rail burning. Since the rail grinding machine is a mobile dry grinding device, coolant or grinding fluid cannot be added during grinding, so the rail burning problem cannot be completely solved. Furthermore, considering the severe edge defects in heavy-haul railways, a separate edge-damping grinding wheel was designed to quickly eliminate these defects.

[0003] In existing impregnation grinding wheel technology, the impregnating agent formulation and process parameters have not been optimized for heavy load, variable pressure, dry grinding and other working conditions of rail grinding, resulting in limited performance improvement. Summary of the Invention

[0004] The purpose of this invention is to overcome the problems existing in the prior art and to provide an impregnating agent for impregnating grinding wheels, an impregnating grinding wheel for a full-range contour turnout grinding vehicle, its preparation method and application.

[0005] The technical problem solved by this invention is achieved by the following technical solution.

[0006] This invention provides an impregnating agent for impregnating grinding wheels, comprising the following components by weight percentage: 5-10% dispersant, 8-25% thermally conductive reinforcing agent, 1-3% coupling agent, 2-5% lubricant, and the balance being water.

[0007] The present invention also provides a full-range contour turnout grinding wheel for a grinding vehicle, comprising a grinding body, wherein: the grinding body comprises a grinding body and a permeation layer permeating into the pores of the grinding body, the permeation layer being formed by permeation treatment with the aforementioned impregnating agent.

[0008] The present invention also provides a method for preparing the above-mentioned full-range contour turnout grinding wheel, which includes: mixing abrasive and binder to form a molding material, assembling it with a hole ring and a reinforcing fiber mesh sheet and pressing it, curing the pressed part, and then immersing it in an impregnating agent for impregnation treatment to obtain the full-range contour turnout grinding wheel.

[0009] The present invention also provides an application of the above-mentioned full-range contour turnout grinding wheel for high-efficiency grinding of heavy-load railway turnouts.

[0010] The present invention has the following beneficial effects: The impregnation grinding wheel prepared using the method of this invention can meet the high-load grinding requirements of rails, and can be matched with the grinding methods of full-range contour turnout grinding machines. It can achieve comprehensive coverage of complex-shaped areas such as guard rails, switch rails, and fork points, and can also handle mainline grinding. Compared with ordinary grinding wheels, the surface roughness of the ground rail is reduced, resulting in better rail surface quality. It also has excellent heat dissipation performance, avoiding rail burns caused by overheating during grinding, extending the service life of the rails, and reducing railway maintenance costs. Attached Figure Description

[0011] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of the impregnation grinding wheel structure; Figure 2 This is a cross-sectional view of the impregnated grinding wheel; Figure 3 This is a schematic diagram of the composition of a grinding body; Figure 4 Flowchart of the impregnation grinding wheel manufacturing process; Figure 5 This is a flow chart of the infiltration process; Figure 6 A schematic diagram of grinding basic rails for turnouts using grinding wheels of various specifications; Figure 7 The image shows the actual impregnated grinding wheel (left) and the surface of the rail after grinding with the impregnated grinding wheel (right). Figure 8 The image shows the actual grinding wheel prepared for Comparative Example 1 (left) and the surface of the rail after grinding with the grinding wheel (right). Figure 9 The image shows the actual grinding wheel prepared for Comparative Example 2 (left) and the surface of the rail after grinding with the grinding wheel (right).

[0013] Explanation of reference numerals in the attached drawings: 1. Grinding body; 2. Reinforcing fiber mesh; 3. Hollow ring; 11. Abrasive; 12. Bonding agent; 13. Pores; 14. Impregnation layer. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0015] The following is a detailed description of an impregnating agent for impregnating grinding wheels, an impregnating grinding wheel for a full-range conformal turnout grinding vehicle, its preparation method, and its application, provided by embodiments of the present invention.

[0016] In a first aspect, the present invention provides an impregnating agent for impregnating grinding wheels, comprising the following components by weight percentage: 5-10% dispersant, 8-25% thermally conductive agent, 1-3% coupling agent, 2-5% lubricant, and the balance being water.

[0017] The dispersant is sodium pyrophosphate and sodium hexametaphosphate, used to disperse powders and liquids that are poorly soluble in water; the thermal conductivity enhancer is graphite and nano-alumina sol, which improves the film hardness and enhances thermal conductivity; the coupling agent is a silane coupling agent, which improves the bonding between the impregnating agent and the pore walls; the lubricant is mica and talc; the impregnating agent design: the silane coupling agent enhances the bonding strength between the film and the grinding body interface, preventing detachment; graphite and nano-alumina synergistically improve thermal conductivity and accelerate heat diffusion, with graphite providing a macroscopic heat conduction path and nano-alumina enhancing microscopic heat diffusion; the lubricant composed of mica and talc reduces the frictional heat generated by abrasive particles when cutting the rail.

[0018] In some alternative embodiments, the dispersant is sodium pyrophosphate and sodium hexametaphosphate; the thermal conductivity enhancer is graphite and nano-alumina sol; the coupling agent is a silane coupling agent; and the lubricant is mica and talc.

[0019] Furthermore, the mass ratio of sodium pyrophosphate to sodium hexametaphosphate in the dispersant is 0.5-0.8:1; the mass ratio of graphite to nano-alumina sol in the thermal conductivity enhancer is 1.5-3:1; and the mass ratio of mica to talc in the lubricant is 0.3-0.8:1. In some alternative embodiments, the dispersion and the thermal conductivity enhancer are mixed in water and ultrasonically treated for 30-60 minutes; a coupling agent is added and the mixture is stirred at 60°C for 1-2 hours; a lubricant is added to form a homogeneous impregnating agent.

[0020] Secondly, the present invention also provides a full-range contour turnout grinding wheel for use in grinding vehicles, see [link to relevant documentation]. Figure 1 and Figure 2 The invention includes an impregnated grinding body 1, which comprises a grinding body and an impregnated layer 14 permeating the pores of the grinding body. The grinding body is composed of abrasive 11, a binder 12, and pores 13 formed by pressing and bonding the abrasive 11 and binder 1 together. The impregnated layer 14 is formed by impregnating the grinding body with the aforementioned impregnating agent. In this invention, an impregnation process is used to adhere the impregnated layer 14 to the pore walls of the pores within the grinding body. By increasing heat dissipation and reducing frictional heat, the technical problem of easy rail burning during full-range contour turnout grinding operations is solved. In some embodiments, a reinforcing fiber mesh is further provided inside the grinding body 1, and a perforated ring (see...) is embedded on the inner circumference of the grinding body. Figure 3 Preferably, the reinforcing fiber mesh sheets inside the grinding body are arranged in layers, and the distance between two adjacent layers of reinforcing fiber mesh sheets inside the grinding body is 6-8 mm. More preferably, the grinding body 1 is provided with reinforcing fiber mesh sheets inside and on both sides. The use of reinforcing fiber mesh sheets and hole ring reinforcement structure greatly improves the strength of the grinding wheel.

[0021] In some optional embodiments, the raw materials for preparing the grinding body include 70-80% abrasive and 20-30% binder. Wherein: the abrasive includes at least one of zirconium corundum and single-crystal corundum, and the binder mainly includes at least one of phenolic resin and neophenolic resin; Preferably, the abrasive is a mixture of zirconium corundum and single-crystal corundum in a mass ratio of 3-5:1; the binder is a mixture of phenolic resin and neophenolic resin in a mass ratio of 3-5:1.

[0022] The impregnation grinding wheel prepared using the method of this invention can meet the high-load grinding requirements of rails, and can be matched with the grinding methods of full-range contour turnout grinding machines. It can achieve comprehensive coverage of complex-shaped areas such as guard rails, switch rails, and fork points, and can also handle mainline grinding. Compared with ordinary grinding wheels, the surface roughness of the ground rail is reduced, resulting in better rail surface quality. It also has excellent heat dissipation performance, avoiding rail burns caused by overheating during grinding, extending the service life of the rails, and reducing railway maintenance costs.

[0023] Thirdly, the present invention provides a method for preparing the above-mentioned full-range contour turnout grinding wheel, see [link to relevant documentation]. Figure 4 and Figure 5 This includes the following steps: Mixing: Weigh each component according to the ratio and mix them using a double-boiler mixer. Add the mixing abrasive to the first pot, stir evenly, and then add the wetting agent and stir. Add the binder to the second pot, and then pour the wetted material from the first pot into the second pot. The mixing speed of the double-boiler mixer is 20-30 rpm, and the total mixing time of the molding material is 5-10 minutes. Molding: Place the perforated ring and the reinforcing fiber mesh sheet into the molding mold, put the molding material into the mold, spread the material evenly, put in another reinforcing mesh sheet, set the pressing and molding pressure to 1-5MPa, and the holding time to 1-5min; Curing: Stepwise temperature increase, maximum curing temperature 180-190℃, total curing time 15-20h; Impregnation: Mix the dispersion and the thermal conductivity enhancer in water, and sonicate for 30-60 minutes; add a coupling agent and stir at 60℃ for 1-2 hours; add a lubricant to form a homogeneous impregnating agent. Place the grinding wheel in a vacuum pressure tank, inject the impregnating agent into the tank, set the water bath impregnation temperature to 60-80℃, the impregnation pressure to 0.5-1MPa, and the impregnation pressurization time to 3-5 minutes; remove the grinding wheel from the tank, install it on a centrifuge and rotate it at high speed to remove excess impregnating agent, set the speed to 3275 rpm, and the dehydration time to 60 seconds; then perform drying treatment at 110℃ for 60 minutes.

[0024] The impregnation process design provided by this invention includes: vacuum pressure impregnation to ensure that the impregnating agent deeply fills the pores and the membrane layer is uniformly covered; and centrifuge drying process to remove excess impregnating liquid and control the thickness of the impregnated membrane layer.

[0025] Fourthly, the present invention provides an application of the above-mentioned full-range contour turnout grinding wheel for high-efficiency grinding of heavy-load railway turnouts.

[0026] The present invention will be further described below with reference to embodiments.

[0027] The ordinary grinding wheels listed in Tables 2, 4, 6, 8, 10 and 12 below consist of grinding bodies, reinforcing fiber mesh sheets and perforated rings, i.e. grinding wheels that have not undergone impregnation treatment.

[0028] Example 1 Component ratio: Grinding layer: 60% zirconium corundum, 15% monocrystalline corundum, 10% phenolic resin, 5% neophenolic resin, and the remainder 10%; 4 sheets of reinforcing fiber mesh; Impregnating agent: sodium pyrophosphate 2%, sodium hexametaphosphate 3%, graphite 6%, nano alumina sol 2%, silane coupling agent 1%, mica 1.8%, talc 2.4%, water 81.8%.

[0029] Main process parameters for grinding wheel preparation: Mixing: The mixing speed of the double-pot mixer is 30 rpm, and the total mixing time of the molding material is 6 minutes; Molding: Assemble the mold, install the aluminum ring on the mold core, divide the mixed material into 5 equal parts according to the total weight and feed it into the mold. After feeding, stir and scrape it evenly, put in a reinforcing fiber mesh sheet, and put in a total of 4 reinforcing fiber mesh sheets. Cold press to form, press the forming pressure 5MPa, and hold the pressure for 1min. Curing: Maximum curing temperature 180℃, total curing time 20h; Impregnation: Impregnation temperature 80℃, impregnation pressure 1MPa, time 5min, dehydration speed 3275rpm, dehydration time 30s, drying temperature 110℃, drying time 60min.

[0030] The specifications and manufacturing process parameters of the impregnated grinding wheels are shown in Table 1.

[0031] Table 1 Specifications and Main Process Parameters for Impregnated Grinding Wheels

[0032] Grinding conditions: Based on the rail defects, select six different sizes of grinding wheels and install them on a full-range contour turnout grinding machine to perform turnout main rail grinding operations. The grinding power is 8-15 kW, with a value of 12 kW being used; the grinding speed is 2-16 km / h, with a value of 3 km / h being used; the maximum linear speed of the grinding wheels is 60 m / s. Different sizes of grinding wheels are used at different angles for rail grinding operations. The rail material being ground is U71Mn.

[0033] Grinding quality: The main indicators of grinding quality include rail surface roughness, rail surface hardness, grinding wheel life, grinding amount, and rail surface bluing. The average values ​​were taken from the data after grinding with different specifications of grinding wheels, and the values ​​were taken from the R200 part of the rail top. The main indicators are shown in Table 2.

[0034] Table 2 Key Indicators of Grinding Quality

[0035] Example 2 Similar to the steps in Example 1, the only difference is that the temperature, pressure, and time parameters in the impregnation wheel preparation process are changed.

[0036] Component ratio: Grinding layer: 60% zirconium corundum, 15% monocrystalline corundum, 10% phenolic resin, 5% neophenolic resin, and the remainder 10%; 4 sheets of reinforcing fiber mesh; Impregnating agent: sodium pyrophosphate 2%, sodium hexametaphosphate 3%, graphite 6%, nano alumina sol 2%, silane coupling agent 1%, mica 1.8%, talc 2.4%, water 81.8%.

[0037] Main process parameters for grinding wheel preparation: Mixing: The mixing speed of the double-pot mixer is 30 rpm, and the total mixing time of the molding material is 6 minutes; Molding: Press molding pressure 5MPa, holding time 1min; Curing: Maximum curing temperature 180℃, total curing time 20h; Impregnation: Impregnation temperature 70℃, impregnation pressure 0.8MPa, time 4min, dehydration speed 3275rpm, dehydration time 30s, drying temperature 110℃, drying time 60min.

[0038] The specifications and manufacturing process parameters of the impregnated grinding wheels are shown in Table 3.

[0039] Table 3 Specifications and Main Process Parameters for Impregnated Grinding Wheels

[0040] Grinding conditions: Based on the rail defects, select six different sizes of grinding wheels and install them on a full-range contour turnout grinding machine to perform turnout main rail grinding operations. The grinding power is 8-15 kW, with a value of 12 kW being used; the grinding speed is 2-16 km / h, with a value of 3 km / h being used; the maximum linear speed of the grinding wheels is 60 m / s. Different sizes of grinding wheels are used at different angles for rail grinding operations. The rail material being ground is U71Mn.

[0041] Grinding quality: The main indicators of grinding quality include rail surface roughness, rail surface hardness, grinding wheel life, grinding amount, and rail surface bluing. The average values ​​were taken from the data after grinding with different specifications of grinding wheels, and the values ​​were taken from the R200 part of the rail top. The main indicators are shown in Table 4.

[0042] Table 4 Key Indicators of Grinding Quality

[0043] Example 3 Similar to the steps in Example 1, the only difference is that the temperature, pressure, and time parameters in the impregnation wheel preparation process are changed.

[0044] Component ratio: Grinding layer: 60% zirconium corundum, 15% monocrystalline corundum, 10% phenolic resin, 5% neophenolic resin, and the remainder 10%; 4 sheets of reinforcing fiber mesh; Impregnating agent: sodium pyrophosphate 2%, sodium hexametaphosphate 3%, graphite 6%, nano alumina sol 2%, silane coupling agent 1%, mica 1.8%, talc 2.4%, water 81.8%.

[0045] Main process parameters for grinding wheel preparation: Mixing: The mixing speed of the double-pot mixer is 30 rpm, and the total mixing time of the molding material is 6 minutes; Molding: Press molding pressure 5MPa, holding time 1min; Curing: Maximum curing temperature 180℃, total curing time 20h; Impregnation: Impregnation temperature 60℃, impregnation pressure 0.5MPa, time 3min, dehydration speed 3275rpm, dehydration time 30s, drying temperature 110℃, drying time 60min.

[0046] The specifications and manufacturing process parameters of the impregnated grinding wheels are shown in Table 5.

[0047] Table 5 Specifications and Main Process Parameters for Impregnated Grinding Wheels

[0048] Grinding conditions: Based on the rail defects, select six different sizes of grinding wheels and install them on a full-range contour turnout grinding machine to perform turnout main rail grinding operations. The grinding power is 8-15 kW, with a value of 12 kW being used; the grinding speed is 2-16 km / h, with a value of 3 km / h being used; the maximum linear speed of the grinding wheels is 60 m / s. Different sizes of grinding wheels are used at different angles for rail grinding operations. The rail material being ground is U71Mn.

[0049] Grinding quality: The main indicators of grinding quality include rail surface roughness, rail surface hardness, grinding wheel life, grinding amount, and rail surface bluing. The average values ​​were taken from the data after grinding with different specifications of grinding wheels, and the values ​​were taken from the R200 part of the rail top. The main indicators are shown in Table 6.

[0050] Table 6 Key Indicators of Grinding Quality

[0051] Example 4 The steps are similar to those in Example 1, except that the proportion of each component in the impregnating agent is changed.

[0052] Component ratio: Grinding layer: 60% zirconium corundum, 15% monocrystalline corundum, 10% phenolic resin, 5% neophenolic resin, and the remainder 10%; 4 sheets of reinforcing fiber mesh; Impregnating agent: sodium pyrophosphate 3%, sodium hexametaphosphate 6%, graphite 15%, nano alumina sol 5%, silane coupling agent 2.5%, mica 2%, talc 2.8%, water 63.7%.

[0053] Main process parameters for grinding wheel preparation: Mixing: The mixing speed of the double-pot mixer is 30 rpm, and the total mixing time of the molding material is 6 minutes; Molding: Press molding pressure 5MPa, holding time 1min; Curing: Maximum curing temperature 180℃, total curing time 20h; Impregnation: Impregnation temperature 60℃, impregnation pressure 0.5MPa, time 3min, dehydration speed 3275rpm, dehydration time 30s, drying temperature 110℃, drying time 60min.

[0054] The specifications and manufacturing process parameters of the impregnated grinding wheels are shown in Table 7.

[0055] Table 7 Specifications and Main Process Parameters for Impregnated Grinding Wheels

[0056] Grinding conditions: Based on the rail defects, select six different sizes of grinding wheels and install them on a full-range contour turnout grinding machine to perform turnout main rail grinding operations. The grinding power is 8-15 kW, with a value of 12 kW being used; the grinding speed is 2-16 km / h, with a value of 3 km / h being used; the maximum linear speed of the grinding wheels is 60 m / s. Different sizes of grinding wheels are used at different angles for rail grinding operations. The rail material being ground is U71Mn.

[0057] Grinding quality: The main indicators of grinding quality include rail surface roughness, rail surface hardness, grinding wheel life, grinding amount, and rail surface bluing. The average values ​​were taken from the data after grinding with different specifications of grinding wheels, and the values ​​were taken from the R200 part of the rail top. The main indicators are shown in Table 8.

[0058] Table 8 Key Indicators of Grinding Quality

[0059] Example 5 The steps are similar to those in Example 1, except that the proportion of each component in the impregnating agent is changed.

[0060] Component ratio: Grinding layer: 60% zirconium corundum, 15% monocrystalline corundum, 10% phenolic resin, 5% neophenolic resin, and the remainder 10%; 4 sheets of reinforcing fiber mesh; Impregnating agent: sodium pyrophosphate 2%, sodium hexametaphosphate 4%, graphite 10%, nano alumina sol 5%, silane coupling agent 1.5%, mica 1.6%, talc 2.2%, water 73.7%.

[0061] Main process parameters for grinding wheel preparation: Mixing: The mixing speed of the double-pot mixer is 30 rpm, and the total mixing time of the molding material is 6 minutes; Molding: Press molding pressure 5MPa, holding time 1min; Curing: Maximum curing temperature 180℃, total curing time 20h; Impregnation: Impregnation temperature 60℃, impregnation pressure 0.5MPa, time 3min, dehydration speed 3275rpm, dehydration time 30s, drying temperature 110℃, drying time 60min.

[0062] The specifications and manufacturing process parameters of the impregnated grinding wheels are shown in Table 9.

[0063] Table 9 Specifications and Main Process Parameters for Impregnated Grinding Wheels

[0064] Grinding conditions: Based on the rail defects, select six different sizes of grinding wheels and install them on a full-range contour turnout grinding machine to perform turnout main rail grinding operations. The grinding power is 8-15 kW, with a value of 12 kW being used; the grinding speed is 2-16 km / h, with a value of 3 km / h being used; the maximum linear speed of the grinding wheels is 60 m / s. Different sizes of grinding wheels are used at different angles for rail grinding operations. The rail material being ground is U71Mn.

[0065] Grinding quality: The main indicators of grinding quality include rail surface roughness, rail surface hardness, grinding wheel life, grinding amount, and rail surface bluing. The average values ​​are taken from the data after grinding with different specifications of grinding wheels, and the values ​​are taken from the R200 part of the rail top. The main indicators are shown in Table 10.

[0066] Table 10 Key Indicators of Polishing Quality

[0067] Example 6 The steps are similar to those in Example 1, except that the proportion of each component in the impregnating agent is changed.

[0068] Component ratio: Grinding layer: 60% zirconium corundum, 15% monocrystalline corundum, 10% phenolic resin, 5% neophenolic resin, and the remainder 10%; 4 sheets of reinforcing fiber mesh; Impregnating agent: sodium pyrophosphate 3.6%, sodium hexametaphosphate 6%, graphite 10%, nano alumina sol 6%, silane coupling agent 2%, mica 1%, talc 3%, water 68.4%.

[0069] Main process parameters for grinding wheel preparation: Mixing: The mixing speed of the double-pot mixer is 30 rpm, and the total mixing time of the molding material is 6 minutes; Molding: Press molding pressure 5MPa, holding time 1min; Curing: Maximum curing temperature 180℃, total curing time 20h; Impregnation: Impregnation temperature 60℃, impregnation pressure 0.5MPa, time 3min, dehydration speed 3275rpm, dehydration time 30s, drying temperature 110℃, drying time 60min.

[0070] The specifications and manufacturing process parameters of the impregnated grinding wheels are shown in Table 11.

[0071] Table 11 Specifications and Main Process Parameters for Impregnated Grinding Wheels

[0072] Grinding conditions: Based on the rail defects, select six different sizes of grinding wheels and install them on a full-range contour turnout grinding machine to perform turnout main rail grinding operations. The grinding power is 8-15 kW, with a value of 12 kW being used; the grinding speed is 2-16 km / h, with a value of 3 km / h being used; the maximum linear speed of the grinding wheels is 60 m / s. Different sizes of grinding wheels are used at different angles for rail grinding operations. The rail material being ground is U71Mn.

[0073] Grinding quality: The main indicators of grinding quality include rail surface roughness, rail surface hardness, grinding wheel life, grinding amount, and rail surface bluing. The average values ​​are taken from the data after grinding with different specifications of grinding wheels, and the values ​​are taken from the R200 part of the rail top. The main indicators are shown in Table 12.

[0074] Table 12 Key Indicators of Grinding Quality

[0075] Combining the experimental results of Examples 1-6 above and Figure 6-7 It can be seen that, within the set impregnation process parameters, when the impregnating agent components and proportions are used to prepare the grinding wheel, the grinding wheel wear ratio, rail surface roughness and hardness fluctuate within a certain range during the actual grinding test. There is no heat accumulation during grinding, and the rail surface does not exhibit a burning or bluing phenomenon after grinding, thus meeting the requirements for on-site use.

[0076] Comparative Example 1 The ordinary grinding wheel, whose composition and steps are similar to those in Example 1, differs only in that the grinding body is not impregnated. The prepared grinding wheel is used to grind the steel rail, and the ground steel rail is shown below. Figure 8 ,Depend on Figure 8 It can be seen that there are localized areas on the rail surface where the rail has been burned and turned blue.

[0077] Comparative Example 2 Similar to the steps in Example 1, except that the nano-alumina sol in the impregnating agent is replaced with quartz powder. See the image below for the polished rail. Figure 9 ,Depend on Figure 9It can be seen that slight burns appeared on the surface of the rail after grinding, and the grinding quality was lower than that of Example 1.

[0078] Comparative Example 3 Similar to the steps in Example 1, the only difference is that the total proportion of mica and talc in the impregnating agent is increased to 8.4%. The impregnating agent composition is: sodium pyrophosphate 2%, sodium hexametaphosphate 3%, graphite 6%, nano-alumina sol 2%, silane coupling agent 1%, mica 3.6%, talc 4.8%, and water 77.6%. Using the prepared grinding wheel to grind the rails, the grinding ratio decreased significantly, the amount of rail cutting decreased, and the grinding quality was lower compared to Example 1.

[0079] Comparative Example 4 Similar to the steps in Example 1, the only difference is that the impregnation process parameters were changed, reducing the impregnation time to 1 minute. Because the impregnation time was too short, the impregnating agent failed to fully penetrate the pores inside the grinding wheel, affecting the grinding quality, which was lower than in Example 1.

[0080] The experimental results above show that ordinary grinding wheels without impregnation are prone to heat accumulation and wheel burning during grinding. Changing the composition of the impregnating agent and the impregnation process will lead to a significant decrease in grinding quality.

[0081] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An impregnating agent for impregnating grinding wheels, characterized in that, The components include, by weight percentage: 5-10% dispersant, 8-25% thermal conductivity enhancer, 1-3% coupling agent, 2-5% lubricant, and the balance being water.

2. The impregnating agent for impregnating grinding wheels according to claim 1, characterized in that, The dispersant includes at least one of sodium pyrophosphate and sodium hexametaphosphate; the thermal conductivity enhancer includes at least one of graphite and nano-alumina sol; the coupling agent is a silane coupling agent; the lubricant includes at least one of mica and talc. Preferably, the dispersant is selected from sodium pyrophosphate and sodium hexametaphosphate in a mass ratio of 0.5-0.8:1; the thermal conductivity enhancer is selected from graphite and nano-alumina sol in a mass ratio of 1.5-3:1; and the lubricant is selected from mica and talc in a mass ratio of 0.3-0.8:

1.

3. The impregnating agent for impregnating grinding wheels according to claim 1 or 2, characterized in that, The impregnating agent for impregnating grinding wheels is prepared by the following method: the dispersion and the thermal conductivity enhancer are mixed in water and ultrasonically treated for 30-60 minutes; a coupling agent is added and the mixture is stirred at 60°C for 1-2 hours; then a lubricant is added to form a homogeneous impregnating agent.

4. A full-range contour turnout grinding wheel with impregnation, characterized in that, The impregnated grinding wheel includes an impregnated grinding body, wherein: the impregnated grinding body includes a grinding body and an impregnated layer permeating into the pores of the grinding body, and the impregnated layer is formed by impregnation treatment using any one of claims 1-3.

5. The impregnated grinding wheel for full-range contour turnout grinding as described in claim 4, characterized in that, The impregnated grinding wheel includes an impregnated grinding body, a reinforcing fiber mesh sheet, and a perforated ring, wherein: the impregnated grinding body includes a grinding body and a permeation layer that penetrates into the pores of the grinding body, the reinforcing fiber mesh sheet is disposed inside the grinding body, and the perforated ring is embedded on the inner circumference of the grinding body; Preferably, the reinforcing fiber mesh sheets located inside the grinding body are arranged in layers, and the distance between two adjacent layers of reinforcing fiber mesh sheets is 6-8 mm; Preferably, reinforcing fiber mesh sheets are provided inside and on both sides of the grinding body.

6. The impregnated grinding wheel for full-range contour turnout grinding as described in claim 5, characterized in that, The grinding body is composed of abrasive, binder, and pores present after the abrasive and binder are pressed and bonded together. The permeation layer is formed by the permeation treatment of the grinding body by the impregnation agent. Preferably, the raw materials for preparing the grinding body include 70-80% abrasive and 20-30% binder, wherein: the abrasive includes at least one of zirconium corundum and single crystal corundum, and the binder mainly includes at least one of phenolic resin and neophenolic resin; Preferably, the abrasive is selected from zirconium corundum and single-crystal corundum in a mass ratio of 3-5:1; the binder is selected from phenolic resin and neophenolic resin in a mass ratio of 3-5:

1.

7. A method for preparing a full-range contour turnout grinding wheel according to any one of claims 5-6, characterized in that, It includes: The molding material formed by mixing abrasive and binder is assembled with perforated rings and reinforcing mesh and then pressed. After the pressed part is cured, it is immersed in impregnation agent for impregnation treatment to obtain a full-range contour turnout grinding wheel.

8. The preparation method according to claim 7, characterized in that, Suppression includes the following steps: Control the pressing pressure to 1-5 MPa, the holding time to 1-5 min, and the pressing includes the following steps: control the curing temperature to 180-190℃, and the total curing time to 15-20 h.

9. The preparation method according to claim 7, characterized in that, The impregnation process includes the following steps: placing the grinding wheel into a vacuum pressure tank, injecting impregnating agent into the tank, setting the water bath impregnation temperature to 60-80℃, the impregnation pressure to 0.5-1MPa, and the impregnation pressurization time to 3-5 minutes; hoisting the grinding wheel out of the tank, installing it on a centrifuge and rotating it at high speed to remove excess impregnating agent, setting the rotation speed to 3275 rpm and the dehydration time to 60 seconds; and then performing a drying treatment at a drying temperature of 110℃ for 60 minutes.

10. The application of the full-range profile turnout grinding wheel for grinding vehicles according to any one of claims 4-6 or the full-range profile turnout grinding wheel for grinding vehicles prepared by the preparation method according to any one of claims 7-9 in the efficient grinding operation of heavy-haul railway turnouts.

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