Straightening linear guide rail air hole grinding wheel and preparation method thereof

Abstract

The present application belongs to the field of grinding wheel, and particularly relates to a large-pore grinding wheel for grinding linear guide rail and a preparation method thereof. The large-pore grinding wheel is mainly prepared from the following raw materials by weight: 100 parts of abrasive and binder, and 7-10 parts of pore-forming material; wherein the binder is used in an amount of 12-18 parts, the binder is high-strength low-temperature ceramic binder, the refractoriness of the high-strength low-temperature ceramic binder is 930-960 DEG C, and the abrasive is composed of ceramic corundum, white corundum and single-crystal corundum at a mass ratio of (10-50):(15-60):20. The large-pore grinding wheel for grinding linear guide rail has good self-sharpening property and high shape retention due to the cooperation of mixed abrasive and low-temperature ceramic binder, and meets the technical requirements of linear guide rail grinding.

Description

Technical Field

[0001] This invention belongs to the field of grinding wheels, specifically relating to a large-pore grinding wheel for grinding linear guideways and its preparation method. Background Technology

[0002] Linear guides are widely used in sliding components of industrial machinery such as precision machine tools, textile machinery, food packaging machinery, and printing machinery. With the rapid development of intelligent manufacturing, the machine tool industry is driven towards higher speeds, greater precision, and energy efficiency, which also places higher demands on the dimensional accuracy, straightness, and stability of linear guides.

[0003] The linear guide rail is mainly made of alloy steel, and its length can reach more than 4 meters. It has grooves machined on both sides to assemble sliders. The groove surface contacts the rolling parts inside the slider. During the machining of the groove, the corresponding parts are surface hardened, resulting in high hardness. This places high demands on the grinding wheel's ability to remove material, the ability to maintain linear shape, and the machining accuracy.

[0004] Existing grinding wheel products are somewhat lacking in their ability to grind linear guides, mainly in the following aspects:

[0005] 1. Dimensional accuracy and conformability need further improvement to meet the requirements of high-precision linear guide products.

[0006] 2. During the grinding process, the workpiece is prone to burns, vibration marks, scratches, and other problems.

[0007] 3. Grinding efficiency is low, requiring frequent dressing. Summary of the Invention

[0008] The purpose of this invention is to provide a large-pore grinding wheel for grinding linear guides, which solves the problems of existing grinding wheels in terms of dimensional accuracy, shape retention, and surface roughness when grinding linear guides.

[0009] The second objective of this invention is to provide a method for preparing the above-mentioned atmospheric perforation grinding wheel for grinding linear guideways.

[0010] To achieve the above objectives, the technical solution adopted by this invention is as follows:

[0011] A grinding wheel for grinding linear guide rails with large pores is mainly made of the following raw materials in parts by weight: 100 parts of abrasive and binder, and 7-10 parts of pore-forming material; wherein, the amount of binder is 12-18 parts, the binder is a high-strength low-temperature ceramic binder, the high-strength low-temperature ceramic binder has a refractoriness of 930-960℃, and the high-strength low-temperature ceramic binder is composed of the following components in mass percentage: SiO2 62-64%, Al2O3 14-16%, Fe2O3 1-2%, K2O 9-10%, Na2O 5-6%, Li2CO3 4-5%, CaCO3 2-3%; the abrasive is composed of ceramic corundum, white corundum, and single crystal corundum in a mass ratio of (10-50):(15-60):20.

[0012] The atmospheric abrasive grinding wheel for grinding linear guideways of the present invention is made of a mixed abrasive composed of a low-temperature ceramic binder and ceramic corundum, white corundum, and single-crystal corundum. The use of this mixed abrasive helps to improve the density and hardness of the grinding wheel, ensuring the cutting sharpness and wear resistance during grinding.

[0013] The low-temperature ceramic binder is designed for use with mixed abrasives, significantly reducing the binder's refractoriness, lowering the grinding wheel's firing temperature, and accelerating the grinding wheel's production cycle. Furthermore, the binder generates a large amount of liquid phase during firing, enabling it to wet the abrasive grain surface over a large area. This results in a strong reaction with the abrasive grains, providing better grain holding power, and also generates a larger amount of glassy phase, improving the overall strength of the grinding wheel. Preferably, the low-temperature ceramic binder has a loss on ignition of 3–4.5%.

[0014] The combination of mixed abrasive and low-temperature ceramic binder gives the grinding wheel good self-sharpening properties and high shape retention, meeting the technical requirements of linear guideway grinding.

[0015] Preferably, the particle size of ceramic corundum is F80, the particle size of white corundum is F80, and the particle size of single-crystal corundum is F100.

[0016] Preferably, the pore-forming material is refined naphthalene with a particle size of F40-F80.

[0017] Preferably, the raw materials include a wetting agent and a binder, wherein the wetting agent is water glass and the binder is dextrin. More preferably, per 100 parts of abrasive and binder, the amount of the wetting agent is 1-5 parts and the amount of the binder is 0.2-1.5 parts. The amount of the wetting agent is preferably 2-3 parts. The water glass is preferably sodium silicate with a modulus of 2.3-2.6% and a density of 1.4-1.6 g / cm³. 3 .

[0018] The above-mentioned method for preparing a grinding wheel with large pores for grinding linear guideways includes the following steps: mixing materials according to the formula, molding, drying, and firing at 1000℃.

[0019] The method for preparing the atmospheric porous grinding wheel for grinding linear guides of the present invention has a suitable combination of binder and firing temperature, which avoids the problem of poor product quality such as foaming and deformation caused by low refractoriness, and also avoids the problem of poor bonding between binder and abrasive grains caused by high refractoriness.

[0020] Preferably, the mixing process includes first dry mixing of the abrasive, then wet mixing with a wetting agent, then mixing with a binder, then mixing with a pore-forming material, and finally sealing and curing the mixture for 12-24 hours.

[0021] Preferably, after mixing, the material is added in 3 to 5 batches. Before the last batch, the material is stirred, leveled, and tamped after each batch. After the last batch, the material is stirred, leveled, and pressed into shape. The pressing pressure is 5 to 10 MPa, and the pressure is held for 30 seconds.

[0022] Preferably, the drying process involves natural drying for one day or drying at 110°C for one day.

[0023] Preferably, the firing time is 16 hours. During firing, the temperature is first raised to 110-120°C and held for 3-4 hours, then raised to 1000°C at a rate of 20-60°C / hour and held at 1000°C for 16 hours, then lowered to 700-800°C at a rate of 50-200°C / hour, then lowered to 150-200°C at a rate of 25-50°C / hour, and then lowered to 55-60°C at a rate of 13-15°C / hour and held for 10-11 hours. Detailed Implementation

[0024] During linear guide machining, the temperature in the grinding zone where the grinding wheel contacts the workpiece reaches extremely high temperatures (up to 1000℃ or higher) during high-speed grinding, easily causing workpiece burns. To improve this situation, it is necessary to design the grinding wheel manufacturing formula to increase or expand the porosity of the grinding wheel (i.e., large-pore grinding wheel) so that coolant and cold air can enter the grinding zone to absorb heat and achieve a cooling effect. At the same time, the pores can remove grinding debris, improving the machining accuracy of the product.

[0025] In this invention, firstly, different types of abrasives are rationally proportioned and combined with a suitable binder formula. Since the bulk density of the mixed abrasive is greater than that of a single abrasive, it helps to improve the density and hardness of the grinding wheel, ensuring cutting sharpness and wear resistance during grinding. Secondly, a special porous formula structure is adopted. A certain proportion of pore-forming agent is added to ensure that there is no burning during the grinding of linear guideways, improving machining accuracy. Finally, combined with an optimized forming process, the dimensional accuracy of the grinding wheel remains consistent when grinding long linear guideway products (e.g., track lengths reaching 4-6m).

[0026] When grinding linear guides, this invention exhibits the following characteristics:

[0027] 1. Improve the cutting ability and durability of the grinding wheel, reduce the frequency of grinding wheel dressing, thereby ensuring the dimensional accuracy and conformity of the guide rail.

[0028] 2. Improve the heat dissipation, chip removal, and uniformity of the grinding wheel to prevent burns, vibration marks, scratches, and other damage to the workpiece.

[0029] To achieve the above characteristics, this invention has conducted research on three aspects: the compatibility between the binder and the abrasive, the compatibility between ceramic corundum abrasive and ordinary abrasive, and the fabrication of micropores.

[0030] Regarding the compatibility between the binder and the abrasive, a low-temperature binder with good self-sharpening properties is used to match the abrasive, enabling the grinding wheel to have high shape retention and meet the technical requirements of linear guideway grinding.

[0031] In abrasive manufacturing, the binder plays a role in bonding and holding the abrasive grains, determining the main properties of the abrasive such as strength, self-sharpening, and service life. Refractoriness is one of the main performance indicators of the binder. If the refractoriness is too high, the binder will not bond firmly with the abrasive grains, which will reduce the hardness and strength of the abrasive. If the refractoriness is too low, it is easy to produce waste products such as foaming and deformation.

[0032] The grinding wheel for grinding linear guideways with large air holes is made of high-strength ceramic low-temperature binder, which provides better abrasive retention, significantly reducing the amount of binder used. This increases the exposed surface area of ​​the abrasive, improves coolant flow, and removes more heat and cutting material, reducing workpiece burn. It is ideal for cold cutting and applications requiring high workpiece surface quality. Simultaneously, the binder's superior abrasive retention significantly improves the wheel's shape retention, reducing the need for frequent dressing and greatly decreasing dressing time and wear on the dresser. Furthermore, the binder significantly increases the wheel's strength, enabling the grinding machine to operate at high feed rates, high linear speeds, and high pressures, greatly improving productivity.

[0033] Regarding the compatibility between ceramic corundum abrasives and ordinary abrasives, a formula that mixes ceramic corundum abrasives with other abrasives is adopted to ensure strong cutting ability and surface roughness that meets grinding requirements during grinding.

[0034] Ceramic corundum abrasives are composed of uniform submicroscopic crystals, possessing sharp abrasive grains, strong cutting ability, and the ability to continuously generate new cutting edges through micro-fracture under pressure, exhibiting excellent self-sharpening properties. Mixing white corundum abrasives in a specific proportion to create grinding wheels achieves the optimal combination of grinding performance and wheel cost. Introducing single-crystal corundum of different particle sizes can further enhance the grinding performance of the grinding wheel.

[0035] By introducing single-crystal corundum of different particle sizes, the packing density of the abrasive can be increased, achieving higher hardness and slightly improved strength with the same binder content. Furthermore, using mixed particle sizes improves grinding efficiency while also enhancing the surface finish of the machined workpiece.

[0036] In the manufacture of micropores, by introducing fine-grained pore-forming agents, the grinding wheel has a micropore structure, exhibiting a special loose structure, which ensures that the grinding wheel is free from burns, vibration marks, etc. when processing workpieces.

[0037] The grinding wheel forming method of the present invention will be further described below.

[0038] Binder: Prepare the binder raw materials (clay, feldspar, borosilicate glass, lithium carbonate, etc.) according to the composition, ball mill for 6 hours, and pass the ball-milled material through a 200-mesh sieve. The material passing through the sieve is the binder. Store it in a sealed container to prevent moisture absorption. The raw material composition by weight percentage is: clay 10%-20%, feldspar 25%-55%, borosilicate glass 10%-25%, and the balance is lithium carbonate. The preferred raw material weight percentage composition is: clay 15%-16%, feldspar 52%-53%, borosilicate glass 28%-29%, and lithium carbonate 5%-6%. Among them, clay improves the plasticity and strength of the blank and increases the refractoriness of the binder; feldspar accelerates melting, reduces the refractoriness and firing temperature of the binder, and firmly binds the abrasive particles together; borosilicate glass accelerates melting, reduces the refractoriness of the binder, improves the fluidity of the binder, and ensures uniform distribution of the binder among the abrasive particles.

[0039] Mixing: Dry mix for 2-4 minutes to ensure uniform distribution of different abrasive particles. Add wetting agent and wet mix for 5-10 minutes. Add binder and mix with abrasive for 8-10 minutes to ensure full bonding of abrasive and binder. Add pore-forming agent and stir for 3-5 minutes. Pass through a 20-mesh sieve twice. Re-weigh to ensure accuracy of the total weight. Finally, seal the mixed material and allow it to ferment for 12-24 hours to ensure good molding properties.

[0040] Controlling the mixing time, multiple sieving and curing processes can ensure that the binder is evenly distributed on the surface of each abrasive grain, thus ensuring the uniformity of the grinding wheel's hardness and good forming performance.

[0041] Molding: The number of feeding stages depends on the size and height of the grinding wheel. Generally, 3-5 feeding stages are required. Except for the last one, each feeding stage requires thorough mixing, leveling, and tamping. Tamping should be done gradually and evenly, starting lightly and increasing pressure. The last tamping stage does not require tamping. Molding pressure is 5-10 MPa, held for 30 seconds. After molding the first piece, check if the actual height matches the theoretical height to determine if the unit weight needs adjustment.

[0042] The control of multiple feeding, stirring, scraping, tamping and holding time in the molding process can ensure that the grinding wheel has good uniformity of structure and prevent the occurrence of problems such as rapid sand shedding and easy burning in some parts.

[0043] Drying: Allow to air dry for one day, then dry in a drying oven at 110°C for another day. Remove the grinding wheel from the drying oven after the oven temperature drops to 40°C.

[0044] Firing: The car-type kiln process is used for sintering, with 1000℃ selected as the sintering temperature and held for 16 hours.

[0045] The drying and firing processes ensure the binder's reactivity and fluidity at high temperatures, giving the grinding wheel high hardness and strength, and minimizing fluctuations during batch production.

[0046] After small-batch grinding tests by the customer, the original product had a dimensional accuracy of 5μm and a service life of 100 pieces / piece. The grinding results of this product are dimensional accuracy ≤5μm, better shape retention, service life of 300 pieces / piece, surface finish ≤0.4μm, reduced dressing frequency, and no burns, vibration marks, scratches, etc.

[0047] The implementation process of the present invention will be described in detail below with reference to specific embodiments.

[0048] I. Specific Embodiments of the Large-Porosity Grinding Wheel for Grinding Linear Guides and its Preparation Method of the Present Invention

[0049] Example 1

[0050] The large-pore grinding wheel for grinding linear guideways in this embodiment is made from the following raw materials in parts by weight: 10 parts of abrasive ceramic corundum F80, 58 parts of white corundum F80, and 20 parts of single-crystal corundum F100; 12 parts of binder; 8 parts of pore-forming material, which is refined naphthalene with a particle size finer than F80; 0.2 parts of dextrin powder; and 2.4 parts of wetting agent water glass, with a modulus M = (SiO2%) / (Na2O%) / Na2O = 2.5 and a density of 1.45 g / cm³. 3 .

[0051] The binder in this embodiment has a refractoriness of 950℃ and a loss on ignition of 3.6%. The refractoriness is determined according to GB / T7322-2007. The loss on ignition test procedure is as follows: 1g of binder is accurately weighed and dried at 110℃ for 1 hour. Then, it is placed in a crucible and heated in an electric furnace at 400℃ for 10 minutes. The temperature is then gradually increased to 1000℃ and heated for another 2 hours. After that, it is removed and weighed after cooling to room temperature.

[0052] The mass percentage composition of the binder is shown in Table 1 below:

[0053] Table 1. Mass percentage composition of the binder in Example 1

[0054] <![CDATA[SiO2]]> <![CDATA[Al2O3]]> <![CDATA[Fe2O3]]> <![CDATA[K2O]]> <![CDATA[Na2O]]> <![CDATA[Li2CO3]]> <![CDATA[CaCO3]]> 62.50 14.00 1.00 9.50 5.00 5.00 3.00

[0055] The method for preparing the large-pore grinding wheel for grinding linear guideways in this embodiment includes the following steps:

[0056] (1) Prepare a binder by using 15 parts clay, 52 parts feldspar, 28 parts borosilicate glass and 5 parts lithium carbonate as binder raw materials. Ball mill the binder raw materials for 6 hours. After ball milling, pass the material through a No. 200 sieve. The material passing through the sieve is the binder. Store it in a sealed container and prevent it from getting damp.

[0057] (2) Use a countercurrent mixer to dry mix each abrasive for 4 minutes, add a wetting agent and wet mix for 5 minutes, then mix the binder and abrasive for 8 minutes, then add the pore-forming material and mix for 3 minutes, pass through a No. 20 sieve twice, weigh again and let it sit for 24 hours.

[0058] (3) The material is added three times. Except for the last addition, each subsequent addition requires thorough mixing, leveling, and tamping. Tamping should be done gradually and evenly, starting lightly and gradually increasing in pressure. Tamping is not required for the last addition. An isostatic pressing head is used to ensure the uniformity of the grinding wheel's structure. The forming pressure is 8 MPa, and the pressure is held for 30 seconds. Afterward, it is allowed to dry naturally for one day, followed by drying in a drying oven at 110℃ for another day. Once the oven temperature drops to 40℃, it is removed from the drying oven to obtain the grinding wheel blank.

[0059] (4) Sintering is carried out using a car kiln process at a sintering temperature of 1000℃ and a holding time of 16h. The specific firing process is shown in Table 2.

[0060] Table 2 shows the firing process of the atmospheric porous grinding wheel in Example 1.

[0061] Temperature range (°C) Heating rate (°C / h) Time required h Cumulative time h 60～120 60 1 1 120 0 3 4 120～300 60 3 7 300～600 20 15 22 600～1000 25 16 38 1000 0 16 54 1000～900 -200 0.5 54.5 900～800 -100 1 55.5 800～700 -50 2 57.5 700～550 -50 3 60.5 550～200 -25 14 74.5 200～60 -14 10 84.5 60 0 10 94.5

[0062] Example 2

[0063] The large-pore grinding wheel for grinding linear guideways in this embodiment is made from the following raw materials in parts by weight: 50 parts of abrasive ceramic corundum F80, 16 parts of white corundum F80, and 20 parts of single-crystal corundum F100; 14 parts of binder; 7 parts of pore-forming material, which is refined naphthalene with a particle size finer than F80; 0.2 parts of dextrin powder; and 2.8 parts of wetting agent water glass, with a modulus M = (SiO2% / SiO2) / (Na2O% / Na2O) = 2.5 and a density of 1.45 g / cm³. 3 .

[0064] The binder in this embodiment has a refractoriness of 950°C and a loss on ignition of 3.6%. The mass percentage composition of the binder is shown in Table 3 below:

[0065] Table 3. Mass percentage composition of the binder in Example 2

[0066] <![CDATA[SiO2]]> <![CDATA[Al2O3]]> <![CDATA[Fe2O3]]> <![CDATA[K2O]]> <![CDATA[Na2O]]> <![CDATA[Li2CO3]]> <![CDATA[CaCO3]]> 62.50 14.00 1.00 9.50 5.00 5.00 3.00

[0067] The method for preparing the large-pore grinding wheel for grinding linear guideways in this embodiment includes the following steps:

[0068] (1) Prepare a binder by using 15 parts clay, 52 parts feldspar, 28 parts borosilicate glass and 5 parts lithium carbonate as binder raw materials. Ball mill the binder raw materials for 6 hours. After ball milling, pass the material through a No. 200 sieve. The material passing through the sieve is the binder. Store it in a sealed container and prevent it from getting damp.

[0069] (2) Use a countercurrent mixer to dry mix each abrasive for 4 minutes, add a wetting agent and wet mix for 5 minutes, then mix the binder and abrasive for 8 minutes, then add the pore-forming material and mix for 3 minutes, pass through two No. 20 sieves, weigh again and let it sit for 24 hours.

[0070] (3) The material is added 5 times in total. Except for the last addition, each subsequent addition requires thorough mixing, leveling, and tamping. Tamping should be done gradually and evenly, starting from light pressure and gradually increasing. Tamping is not required for the last addition. An isostatic pressing head is used to ensure the uniformity of the grinding wheel's structure. The forming pressure is 8 MPa, and the pressure is held for 30 seconds. Afterward, it is allowed to dry naturally for one day, followed by drying in a drying oven at 110℃ for another day. Once the oven temperature drops to 40℃, it is removed from the drying oven to obtain the grinding wheel blank.

[0071] (4) Sintering was carried out using a car kiln process at a sintering temperature of 1000℃ and a holding time of 16h. The specific firing process was the same as in Example 1.

[0072] II. Comparative Example

[0073] Comparative Example 1

[0074] The large-pore grinding wheel for grinding linear guideways in this embodiment is made from the following raw materials in parts by weight: 10 parts of abrasive ceramic corundum F80, 58 parts of white corundum F80, and 20 parts of single-crystal corundum F100; 12 parts of binder; 8 parts of pore-forming material, which is refined naphthalene with a particle size finer than F80; 0.2 parts of dextrin powder; and 2.4 parts of wetting agent water glass, with a modulus M = (SiO2%) / (Na2O%) / Na2O = 2.5 and a density of 1.45 g / cm³. 3 .

[0075] The binder in this embodiment has a refractoriness of 850°C and a loss on ignition of 3.5%. The mass percentage composition of the binder is shown in Table 4 below:

[0076] Table 4. Composition of binder by mass percentage in Comparative Example 1

[0077] <![CDATA[SiO2]]> <![CDATA[Al2O3]]> <![CDATA[Fe2O3]]> <![CDATA[K2O]]> <![CDATA[Na2O]]> <![CDATA[Li2CO3]]> <![CDATA[CaCO3]]> 58.50 16.00 1.00 9.50 5.00 7.00 3.00

[0078] The method for preparing the large-pore grinding wheel for grinding linear guideways in this embodiment includes the following steps:

[0079] (1) Prepare a binder by using 16 parts clay, 50 parts feldspar, 27 parts borosilicate glass, and 7 parts lithium carbonate as binder raw materials. Ball mill the binder raw materials for 6 hours. After ball milling, pass the material through a No. 200 sieve. The material passing through the sieve is the binder. Store it in a sealed container and prevent it from getting damp.

[0080] (2) Use a countercurrent mixer to dry mix each abrasive for 4 minutes, add a wetting agent and wet mix for 5 minutes, then mix the binder and abrasive for 8 minutes, then add the pore-forming material and mix for 3 minutes, pass through two No. 20 sieves, weigh again and let it sit for 24 hours.

[0081] (3) The material is added 5 times in total. Except for the last addition, each subsequent addition requires thorough mixing, leveling, and tamping. Tamping should be done gradually and evenly, starting from light pressure and gradually increasing. Tamping is not required for the last addition. An isostatic pressing head is used to ensure the uniformity of the grinding wheel's structure. The forming pressure is 8 MPa, and the pressure is held for 30 seconds. Afterward, it is allowed to dry naturally for one day, followed by drying in a drying oven at 110℃ for another day. Once the oven temperature drops to 40℃, it is removed from the drying oven to obtain the grinding wheel blank.

[0082] (4) Sintering was carried out using a car kiln process at a sintering temperature of 1000℃ and a holding time of 16h. The specific firing process was the same as in Example 1.

[0083] Comparative Example 2

[0084] The large-pore grinding wheel for grinding linear guideways in this embodiment is made from the following raw materials in parts by weight: 50 parts of abrasive ceramic corundum F80, 16 parts of white corundum F80, and 20 parts of single-crystal corundum F100; 14 parts of binder; 7 parts of pore-forming material, which is refined naphthalene with a particle size finer than F80; 0.2 parts of dextrin powder; and 2.8 parts of wetting agent water glass, with a modulus M = (SiO2% / SiO2) / (Na2O% / Na2O) = 2.5 and a density of 1.45 g / cm³. 3 .

[0085] The binder in this embodiment has a refractoriness of 850°C and a loss on ignition of 3.5%. The mass percentage composition of the binder is shown in Table 5 below:

[0086] Table 5. Composition of binder by mass percentage in Comparative Example 2

[0087] <![CDATA[SiO2]]> <![CDATA[Al2O3]]> <![CDATA[Fe2O3]]> <![CDATA[K2O]]> <![CDATA[Na2O]]> <![CDATA[Li2CO3]]> <![CDATA[CaCO3]]> 58.50 16.00 1.00 9.50 5.00 7.00 3.00

[0088] The method for preparing the large-pore grinding wheel for grinding linear guideways in this embodiment includes the following steps:

[0089] (1) Prepare a binder by using 16 parts clay, 50 parts feldspar, 27 parts borosilicate glass, and 7 parts lithium carbonate as binder raw materials. Ball mill the binder raw materials for 6 hours. After ball milling, pass the material through a No. 200 sieve. The material passing through the sieve is the binder. Store it in a sealed container and prevent it from getting damp.

[0090] (2) Use a countercurrent mixer to dry mix each abrasive for 4 minutes, add a wetting agent and wet mix for 5 minutes, then mix the binder and abrasive for 8 minutes, then add the pore-forming material and mix for 3 minutes, pass through two No. 20 sieves, weigh again and let it sit for 24 hours.

[0091] (3) The material is added 5 times in total. Except for the last addition, each subsequent addition requires thorough mixing, leveling, and tamping. Tamping should be done gradually and evenly, starting from light pressure and gradually increasing. Tamping is not required for the last addition. An isostatic pressing head is used to ensure the uniformity of the grinding wheel's structure. The forming pressure is 8 MPa, and the pressure is held for 30 seconds. Afterward, it is allowed to dry naturally for one day, followed by drying in a drying oven at 110℃ for another day. Once the oven temperature drops to 40℃, it is removed from the drying oven to obtain the grinding wheel blank.

[0092] (4) Sintering was carried out using a car kiln process at a sintering temperature of 1000℃ and a holding time of 16h. The specific firing process was the same as in Example 1.

[0093] III. Experimental Examples

[0094] The grinding wheel produced in Example 1 has a hardness value of 2.7 and 2.8 in the 5-chamber sandblasting hardening machine (the 5-chamber sandblasting machine sprays 5 cubic centimeter quartz sand particles onto the surface of the grinding wheel under compressed air at 0.15 MPa, creating a small pit in the grinding wheel, and the hardness of the grinding wheel is determined by the depth of this pit). Through grinding tests on a 4m guide rail processed by a customer, the dimensional accuracy of the workpiece is 4-5 μm, the surface roughness is ≤0.3 μm, the service life is 100 pieces / piece, and there are no burns, vibration marks, or other defects, which can meet the customer's production needs.

[0095] The grinding wheel produced in Example 2 has a hardness of 3.3 and 3.4 in the 5th chamber of the sandblasting hardening machine. Through grinding tests on a 4m guide rail processed by the customer, the dimensional accuracy of the workpiece is 5μm, the surface roughness is ≤0.3μm, the service life is 306 pieces / piece, and there are no burns, vibration marks, etc., which meets the customer's requirements.

[0096] The grinding wheel made in Comparative Example 1 has a hardness value of 2.1 and 2.2 in the 5th chamber of the sandblasting hardening machine. Through grinding tests on a 4m guide rail processed by a customer, the grinding wheel showed problems such as workpiece burn, vibration marks and insufficient cutting ability during use. It could not maintain the accuracy and could not meet the technical specifications of the guide rail product.

[0097] The grinding wheel made in Comparative Example 2 had a hardness of 2.7 and 2.8 in the 5th chamber of the sandblasting hardening machine. Through grinding tests on a 4m guide rail processed by a customer, the grinding wheel showed severe vibration marks during use, resulting in insufficient surface finish and dimensional accuracy of the guide rail product, which could not meet the product's technical specifications.

[0098] This shows that the binder and abrasive mixture in Comparative Examples 1 and 2 are incompatible and cannot meet the customer's processing requirements. However, Examples 1 and 2 demonstrate that selecting a suitable binder and abrasive mixture results in grinding wheels with a machining accuracy of ≤5μm for linear guides, good shape retention, a surface roughness of ≤0.4μm, and a service life that meets customer needs. This also reduces the frequency of dressing and eliminates issues such as burns, vibration marks, and scratches. The grinding wheel in Example 2 achieved a service life of 300 wheels / wheel.

Claims

1. A grinding wheel with large air holes for grinding linear guideways, characterized in that, It is made from the following raw materials in parts by weight: 100 parts abrasive and binder, 7-10 parts pore-forming material, 1-5 parts wetting agent, and 0.2-1.5 parts binder; wherein, the amount of binder is 12-18 parts, the binder is a high-strength low-temperature ceramic binder, the refractoriness of the high-strength low-temperature ceramic binder is 930-960℃, and the high-strength low-temperature ceramic binder is composed of the following components in mass percentage: SiO2 62-64%, Al2O3 14-16%, Fe2O3 1-2%, K2O 9-10%, Na2O 5-6%, Li2CO3 4-5%, CaCO3 2-3%; the abrasive is composed of ceramic corundum, white corundum, and single crystal corundum in a mass ratio of (10-50):(15-60):20; the wetting agent is water glass, and the binder is dextrin.

2. The grinding wheel for grinding large air holes of linear guideways as described in claim 1, characterized in that, The particle size of ceramic corundum is F80, the particle size of white corundum is F80, and the particle size of single-crystal corundum is F100.

3. The grinding wheel for grinding large air holes of linear guideways as described in claim 1, characterized in that, The pore-forming material is refined naphthalene with a particle size of F40-F80.

4. A method for preparing a large-pore grinding wheel for grinding linear guideways as described in any one of claims 1 to 3, characterized in that, The process includes the following steps: mixing materials according to the formula, molding, drying, and firing at 1000℃.

5. The method for preparing a large-pore grinding wheel for grinding linear guideways as described in claim 4, characterized in that, The mixing process includes first dry mixing of the abrasive, then wet mixing with a wetting agent, then mixing with a binder, then mixing with a pore-forming material, and finally sealing and curing the mixture for 12-24 hours.

6. The method for preparing a large-pore grinding wheel for grinding linear guideways as described in claim 4 or 5, characterized in that, After mixing, the material is added in 3 to 5 batches. Before the last batch, the material is stirred, leveled, and tamped after each batch. After the last batch, the material is stirred, leveled, and pressed into shape. The pressing pressure is 5 to 10 MPa, and the pressure is held for 30 seconds.

7. The method for preparing a large-pore grinding wheel for grinding linear guideways as described in claim 4, characterized in that, The drying process involves natural drying for one day and drying at 110°C for one day.

8. The method for preparing a large-pore grinding wheel for grinding linear guideways as described in claim 4 or 7, characterized in that, During the firing process, the temperature is first raised to 110-120℃ and held for 3-4 hours. Then, the temperature is raised to 1000℃ at a rate of 20-60℃ / h and held at 1000℃ for 16 hours. After that, the temperature is lowered to 700-800℃ at a rate of 50-200℃ / h, then lowered to 150-200℃ at a rate of 25-50℃ / h, and then lowered to 55-60℃ at a rate of 13-15℃ / h and held for 10-11 hours.