Double-wheel milling disc tool bit and manufacturing method thereof

Abstract

The invention discloses a double-wheel milling disc tool bit and a manufacturing method thereof.The double-wheel milling disc tool bit comprises a mounting base, a tool bit base body and a tool bit blade part, the mounting base is suitable for being arranged on the peripheral side of a hub, the tool bit base body comprises a first part and a second part which are connected with each other, the first part is arranged in the mounting base, the second part is located outside a mounting groove, and the tool bit blade part is located in the mounting groove; a mounting groove penetrating through the second part in the length direction of the mounting base is formed in one side of the second part, and the tool bit blade part is made of TiC, WC and alloy steel powder and detachably arranged in the mounting groove in the back of the tool bit base body, so that the tool bit blade part is convenient to replace when the tool bit blade part is abraded. The double-wheel milling disc tool bit has the advantages of being low in cost, convenient to replace, long in service life and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of underground foundation construction, and particularly relates to a low-cost, repairable double-wheel milling disc cutter head structure and a manufacturing method thereof. Background Art

[0002] With the rapid development of urban high-rise buildings, rail transit, etc., mixing drilling rig trenching equipment has emerged. This equipment is mainly used in the construction of underground continuous walls and foundation reinforcement. The milling head of the double-wheel mixing drilling rig is driven by two waterproof gearboxes to mill and cut the surrounding original soil, promote the mixing of the in-situ soil and cement slurry, and can cut hard soil layers such as gravel bottom layer and rock layer. It is widely used in the fields of building foundation reinforcement, water-stopping enclosure structure, water conservancy and underground engineering anti-seepage. The milling disc cutter head of the double-wheel mixing drilling rig continuously mixes and drills in the underground soil, and often encounters hard soil layers such as rocks. The wear of the milling head cutter is accelerated, and the service life is greatly reduced.

[0003] In the related technology, the cutter head of the milling head is mainly made of high manganese steel, high-speed steel, integral tungsten carbide or welded tungsten carbide. High manganese steel and high-speed steel have a short service life, and frequent replacement of the cutter head seriously affects the milling efficiency. The overall use of tungsten carbide cutter heads can greatly extend the service life of the cutter heads, but they will break when encountering hard soil layers such as rocks. Welded tungsten carbide cutter heads will fall off when encountering hard rocks during the milling process due to loose welding of the tungsten carbide head. Summary of the invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] To this end, an embodiment of the present invention provides a double-wheel milling disc cutter head with long service life, convenient replacement, and long milling life.

[0006] The embodiment of the present invention provides a method for manufacturing a double-wheel milling disc cutter head with simple steps and low cost.

[0007] According to an embodiment of the present invention, a double-wheel milling disc cutter head includes: a mounting seat, which is suitable for being arranged on the outer peripheral side of the wheel hub; a cutter head base, which includes a first part and a second part connected to each other, the first part is arranged in the mounting seat, the second part is located outside the mounting groove, and one side of the second part is provided with a mounting groove that penetrates the second part along the length direction of the mounting seat; a cutter head blade, the cutter head blade is made of TiC, WC and alloy steel and is detachably arranged in the mounting groove on the back of the cutter head base, so as to replace the cutter head blade when the cutter head blade is worn.

[0008] The double-wheel milling disc cutter head of the embodiment of the present invention improves the wear resistance and service life of the cutter head blade by adding TiC and WC to the cutter head blade, reduces the replacement of the cutter head blade, and improves the milling efficiency of the double-wheel milling disc cutter head. The cutter head blade and the cutter head base are detachably connected, so the cutter head blade can be replaced when the cutter head blade is worn, thereby reducing the processing and manufacturing cost of the double-wheel milling disc cutter head.

[0009] In some embodiments, the double-wheel milling disc cutter head also includes: a fastener, a mounting hole extending along the width direction of the mounting seat is provided on the cutting edge of the cutter head, and the fastener is passed through the mounting hole and the second part, so that the cutting edge of the cutter head is detachably connected to the second part through the fastener; a column nail, the outer peripheral surface of the column nail is coated with organic glue and is passed through the mounting hole and is located on the side of the fastener away from the second part; a gasket, the gasket is arranged in the mounting hole and is located between the fastener and the column nail.

[0010] In some embodiments, the outer peripheral surface of the tool head substrate is coated with a self-fluxing alloy wear-resistant layer.

[0011] The method for preparing a double-wheel milling disc cutter head according to an embodiment of the present invention includes: S1: Evenly mix 200-350 mesh TiC powder, WC powder, alloy steel powder and a binder to obtain a mixed powder. S2: Press the mixed powder into the shape of a cutter head blade, and then sinter the pressed mixed powder into a cutter head blade; S3: Heat treat the sintered cutter head blade to make the hardness of the cutter head blade 61HRC-64HRC. S4: Select a carbon steel forging as the cutter head base, and heat treat the cutter head base to improve the strength and toughness of the cutter head base; S5: Removably mount the cutter head blade on the cutter head base.

[0012] In some embodiments, in step S1, the content of the TiC powder is 35%-45%, the content of the WC powder is 5%-10%, the content of the binder is 4%-8%, and the alloy steel powder includes 0.9%-1.1% C, 1.0%-1.5% Mn, 2.5%-3.5% Ni, 2.5%-3.0% Mo, 0.5%-1.0% Ti, 1.5%-2.0% V, 0.5%-1.0% Nb, and the balance is iron.

[0013] In some embodiments, in step S2, the mixed powder is filled in a double-wheel milling disc cutter blade mold, and is molded using a press at a pressure of 10MPa-20MPa. After molding and demolding, the cutter blade blank is placed in a vacuum sintering furnace with a vacuum degree below 20Pa, and slowly heated to 1450℃-1500℃ for sintering. After keeping warm for 2-3 hours, argon is introduced for hot isostatic pressing and kept warm for 1-2 hours with an argon introduction amount of 4MPa-6MPa. The cutter blade is slowly cooled in the furnace and taken out of the furnace.

[0014] In some embodiments, in step S3, the heat treatment includes: S3.1: vacuum heat treating the cutting edge of the blade at a temperature between 1050°C and 1150°C, and then keeping it in a salt bath at a temperature of 560°C to 600°C for 0.5-1 hour and then air cooling it to obtain a cutting edge with a hardness of 62HRC-65HRC; S3.2: performing secondary tempering on the cutting edge of the blade at a temperature between 500°C and 600°C to obtain a cutting edge with a hardness of 61HRC-64HRC.

[0015] In some embodiments, in step S4, carbon steel is forged at a temperature ranging from 850° C. to 1000° C. to form a tool head substrate, and the carbon steel has a carbon content of 0.30% to 0.40%.

[0016] In some embodiments, the method for preparing a double-wheel milling disc cutter head also includes step S6: the cutter head blade has a mounting hole extending along its width direction, the cutter head blade is installed on the cutter head base, and is connected to the cutter head base through a fastener passing through the mounting hole and the fastener is located in the mounting hole, a low-carbon steel gasket with a thickness of 1mm-2mm is arranged in the mounting hole and fits with the fastener, and then a carbide stud coated with an organic adhesive is installed in the mounting hole and connected to the gasket, and it is ensured that the adhesive overflows evenly from the gap between the mounting hole and the stud.

[0017] In some embodiments, the method for preparing a double-wheel milling disc cutter head further includes step S7: after preheating the cutter head base to 250° C.-270° C., spray-welding a 1-2 mm self-fluxing alloy wear-resistant layer on the surface of the cutter head base. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the structure of the milling wheel according to the embodiment of the present invention.

[0019] Figure 2 yes Figure 1 A partial enlarged view of middle A.

[0020] Double wheel milling disc cutter head 100;

[0021] Mounting seat 1; wheel hub 2; cutter head base 3; process hole 31; first part 32; second part 33; cutter head blade 4; fastener 5; stud 6. DETAILED DESCRIPTION

[0022] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0023] A double wheel milling disc cutter head 100 according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0024] like Figure 1-2 As shown, the double-wheel milling disc cutter head 100 according to the embodiment of the present invention comprises a mounting seat 1 , a cutter head base body 3 and a cutter head cutting edge 4 .

[0025] The mounting seat 1 is suitable for being arranged on the outer peripheral side of the wheel hub 2. Specifically, Figure 1-2 As shown, the mounting seat 1 can be arranged on the hub 2 of the double-wheel milling disc.

[0026] The cutter head base 3 includes a first portion 32 and a second portion 33 connected to each other, the first portion 32 is arranged in the mounting seat 1, the second portion 33 is located outside the mounting groove, and one side of the second portion 33 is provided with a longitudinal direction of the mounting seat 1 (such as Figure 2 The mounting groove of the second part 33 is formed in the vertical direction as shown in FIG. Figure 1-2 As shown, the cutter head base 3 is a carbon steel forging and is arranged on the mounting seat 1, the first part 32 is arranged below the second part 33 and is connected to the second part 33, the first part 32 is installed in the mounting seat 1, the second part 33 is above the mounting seat 1 and is arranged on the left half of the upper end surface of the first part 32, and the right half of the upper end surface of the first part 32 and the right side surface of the second part 33 define a mounting groove.

[0027] The blade 4 of the cutter head is made of TiC, WC and alloy steel and is detachably mounted in the mounting groove of the cutter head base 3 so as to facilitate replacement of the blade 4 when the blade 4 of the cutter head is worn. Figure 1-2 As shown, the cutter blade 4 is arranged in the installation groove and the left side surface of the cutter blade 4 is fitted with the right side surface of the second part 33, and the sum of the dimensions of the second part 33 in the left and right directions and the dimensions of the cutter blade 4 in the left and right directions is equal to the sum of the dimensions of the cutter base 3 in the left and right directions. The cutter blade 4 is detachably arranged in the installation groove. When the cutter blade 4 is worn, the cutter blade 4 can be replaced. Thus, the cutter blade 4 can be repaired and the cutter base 3 can be reused, which reduces the processing and manufacturing cost of the cutter base 3. At the same time, the material cost of the cutter blade 4 is also reduced, and the overall low cost and high wear resistance of the cutter base 3 and the cutter blade 4 are achieved.

[0028] The materials and contents of the blade 4 of the cutter head are respectively: 35%-45% TiC, 5%-10% WC, 0.9%-1.1% C, 1.0%-1.5% Mn, 2.5%-3.5% Ni, 2.5%-3.0% Mo, 0.5%-1.0% Ti, 1.5%-2.0% V, 0.5%-1.0% Nb, and the balance is iron. Through the combined effect of TiC, WC and alloy, the hardenability of the blade 4 of the cutter head is improved, making the setting of the blade 4 of the cutter head more reasonable.

[0029] The double-wheel milling disc cutter head 100 of the embodiment of the present invention has a cutter head blade 4 made of TiC, WC and alloy steel powder materials and a cutter head base 3 made of carbon steel forgings, so that the cost of raw materials for manufacturing the double-wheel milling disc cutter head 100 is lower than that of the overall cutter head blade 4 made of tungsten steel or tool steel as raw materials, thereby reducing the processing and manufacturing cost of the double-wheel milling disc cutter head 100, and the added life of TiC powder and WC powder is more than 5 times that of high manganese steel or high-speed steel, reducing the shutdown time for replacing the cutter head by more than 4 times, improving the hardenability and wear resistance of the cutter head blade 4, making it easier for the cutter head blade 4 to mill hard rock and soil layers, improving the milling efficiency of the cutter head blade 4, and is not prone to the problem of brittle fracture of the cutter head blade 4, thereby extending the service life of the cutter head blade 4, the cutter head base 3 is a carbon steel forging, and the cost of the double-wheel milling disc cutter head 100.

[0030] In addition, the double-wheel milling disc cutter head 100 of the embodiment of the present invention is provided with a cutter head blade 4 and a cutter head base 3. When the cutter head blade 4 is worn, since the cutter head blade 4 and the cutter head base 3 are made of different materials and are not integrally formed and are detachably connected, the worn cutter head blade 4 can be removed from the cutter head base 3 and a new cutter head blade 4 can be reinstalled on the cutter head base 3 to replace the cutter head blade 4, thereby reducing the replacement cost of the cutter head base 3 and saving the processing and manufacturing cost of the milling wheel.

[0031] Secondly, the double-wheel milling disc cutter head 100 of the embodiment of the present invention is configured with the first part 32 and the second part 33 so that the first part 32 of the cutter head base 3 can provide support for the cutter head blade 4 in the up and down directions, and the second part 33 of the cutter head base 3 can provide support for the cutter head blade 4 in the left and right directions, thereby preventing the cutter head blade 4 from breaking due to a large cutting force, thereby ensuring that the cutting force and service life of the cutter head blade 4 are extended.

[0032] In some embodiments, the double wheel milling disc cutter head 100 further includes a fastener 5, a stud 6 and a washer (not shown in the figure).

[0033] The blade portion 4 is provided with a mounting hole extending along the width direction of the mounting seat 1, and the fastener 5 is inserted into the mounting hole and into the second portion 33, so that the blade portion 4 is detachably connected to the second portion 33 through the fastener 5. Specifically, Figure 1-2 As shown, a mounting hole extending in the left-right direction is provided on the blade portion 4 of the cutter head, and the fastener 5 can be a screw or a bolt. The fastener 5 passes through the mounting hole and is connected to the second part 33, so that the blade portion 4 of the cutter head is detachably connected to the cutter head base 3 through the fastener 5.

[0034] The outer peripheral surface of the stud 6 is coated with organic glue and is inserted into the mounting hole and is located on the side of the fastener 5 away from the second portion 33. Figure 1-2 As shown, the column nail 6 is a carbide column nail 6, and the organic glue can be an epoxy AB glue. The organic glue is coated on the entire outer surface of the column nail 6 and penetrated into the mounting hole. Therefore, through the cooperation of the column nail 6 and the organic glue, the mounting hole can be sealed to prevent the cut debris from flowing into the mounting hole, so as to ensure the high hardness and high wear resistance of this area.

[0035] The gasket is arranged in the mounting hole and between the fastener 5 and the stud 6. Specifically, the gasket is a low-carbon steel gasket with a thickness of 1mm-2mm and is arranged between the fastener 5 and the stud 6. The left end of the stud 6 is inserted into the gasket, thereby preventing the organic adhesive from penetrating into the head of the fastener 5 through the gasket, playing the role of isolating the adhesive so that the fastener 5 can be disassembled. When disassembly is required, only the stud 6 is heated to melt the organic adhesive, and then the stud 6, the gasket and the fastener 5 are disassembled in turn. In addition, due to the arrangement of the fastener 5, the stud 6 and the gasket, there is no need to weld the blade containing WC. Compared with the related art, it solves the problem that the tungsten carbide head will fall off due to the loose welding when encountering hard rocks during milling.

[0036] In some embodiments, the outer peripheral surface of the cutter head base 3 is coated with a self-fluxing alloy wear-resistant layer. Specifically, the self-fluxing alloy is an iron-based self-fluxing alloy. First, the cutter head base 3 is preheated to 250° C.-270° C., and then a 1mm-2mm self-fluxing alloy wear-resistant layer is spray-welded on the surface of the cutter head base 3, thereby increasing the service life of the cutter head base 3.

[0037] As attached Figure 1-2The double-wheel milling disc cutter head 100 of the double-wheel agitator comprises a TiC composite WC steel-bonded carbide cutter head blade 4 that contacts the underground soil layer during milling, a cutter head base 3, a fastener 5, a TiC composite WC steel-bonded carbide column nail 6, a self-fluxing alloy wear-resistant layer, a welding process hole 31 and a cutter head mounting hole, wherein the TiC composite WC steel-bonded carbide cutter head blade 4 is fixedly connected to the cutter head base 3 by bolts; the cutter head base 3 adopts a medium-carbon steel forging with good comprehensive mechanical properties, and is fixed on the cutter head mounting seat 1 by welding, and the cutter head base 3 is provided with a welding process hole 31, which plays a role in releasing stress, and the self-fluxing alloy wear-resistant layer on the surface of the cutter head base 3 is also slightly worn by the underground soil material during operation, which plays a role in protecting the cutter head base 3; after the cutter head blade 4 is worn out and fails, the cutter head blade 4 can be replaced by disassembling and assembling the TiC composite WC steel-bonded carbide column nail 6 and the fastener 5, thereby realizing low cost and repairability of the cutter head.

[0038] The method for preparing a double-wheel milling disc cutter head according to an embodiment of the present invention includes steps S1 to S5.

[0039] S1: 200-350 mesh TiC powder, WC powder, alloy steel powder and binder are mixed uniformly to obtain a mixed powder. Specifically, 200-350 mesh TiC powder, WC powder and alloy steel powder are mixed uniformly with a binder in a mixer to obtain a mixed powder.

[0040] S2: Press the mixed powder into the shape of the blade 4, and then sinter the pressed mixed powder into the blade 4. Specifically, press the mixed powder into the shape of the blade 4, and then sinter the pressed mixed powder into the blade 4 at high temperature.

[0041] S3: heat-treating the sintered blade 4 to make the hardness of the blade 4 between 61HRC and 64HRC. Thus, the hardness of the blade 4 is improved by heat treatment to make the hardness of the blade 4 between 61HRC and 64HRC to ensure the service life and cutting efficiency of the blade 4.

[0042] S4: A carbon steel forging is selected as the cutter head base 3, and the cutter head base 3 is heat treated to improve the toughness of the cutter head base 3. Specifically, since the carbon steel forging has the advantages of high strength, high wear resistance and low cost, the carbon steel forging is selected as the raw material of the cutter head base 3, which reduces the service life of the cutter head base 3 while improving the service life of the cutter head base 3. By heat treating the cutter head base 3, the toughness and wear resistance of the cutter head base 3 are improved.

[0043] S5: The cutter head blade 4 is detachably mounted on the cutter head base 3. Thus, when the cutter head blade 4 is worn, the cutter head blade 4 can be replaced.

[0044] The method for preparing the double-wheel milling disc cutter head 100 according to the embodiment of the present invention comprises steps S1 to S5, and can prepare the cutter head cutting edge 4 and the cutter head base 3. The preparation method is reasonable and the preparation cost is low.

[0045] In some embodiments, in step S1, the content of TiC powder is 35%-45%, and the content of WC powder is 5%-10%. Specifically, the addition of TiC powder and WC powder can form a cemented carbide phase with high hardness, high wear resistance and excellent thermal hardness, so as to improve the wear resistance life of the blade 4 of the cutter head at room temperature and high temperature. The cemented carbide phase after adding TiC powder and WC powder has higher hardness and wear resistance. Although the cemented carbide phase after adding TiC powder and WC powder has high hardness and good wear resistance, it is brittle and may break when encountering hard rocks during milling. Therefore, setting the TiC powder in the range of 35%-45% and the WC powder in the range of 5%-10% can ensure the toughness of the blade 4 of the cutter head, and also ensure the wear resistance of the blade 4 of the cutter head.

[0046] In some embodiments, the binder content is 4%-8%, and the alloy steel powder includes 0.9%-1.1% C, 1.0%-1.5% Mn, 2.5%-3.5% Ni, 2.5%-3.0% Mo, 0.5%-1.0% Ti, 1.5%-2.0% V, 0.5%-1.0% Nb, and the balance is iron. Specifically, 0.9%-1.1% C can ensure that the alloy steel is a high-carbon tool steel, 1.0%-1.5% Mn can improve the hardenability and wear resistance of the alloy steel. If the Mn content is too high, it will lead to grain coarsening and temper brittleness of the alloy steel. Too low Mn will affect the hardenability and wear resistance of the alloy steel; 2.5%-3.5% Ni can refine the grains and improve the plasticity and toughness of the alloy steel; 2.5%-3.0% Mo can improve the hardenability of the alloy steel, and at the same time form dispersed special carbides at a higher tempering temperature, which has a secondary hardening effect and improves the hot hardness of the alloy steel; 0.5%-1.0% T i has a solid solution strengthening effect, can improve the hardenability and tempering resistance of alloy steel, has a secondary hardening effect, and also has a certain aging strengthening effect; 1.5-2.0% V can improve the hardenability and tempering resistance of steel, has a strong secondary hardening effect, has a grain refinement effect, and at the same time, vanadium carbide is the hardest and most wear-resistant among metal carbides, which can increase the service life of steel; 0.5-1.0% niobium has a strong solid solution strengthening effect, improves the strength of the material, can significantly improve the hardenability of alloy steel, and has a grain refinement effect, improves the impact toughness of steel and reduces its brittle transition temperature, and can improve the thermal strength of alloy steel. Therefore, through the combined action of TiC, WC, C, Mn, Ni, Mo, Ti, V, Nb and Fe materials, the hardenability and wear resistance of the blade 4 of the cutter head are improved, the service life of the blade 4 of the cutter head is extended, and the setting of the blade 4 of the cutter head is more reasonable.

[0047] In some embodiments, in step S2, the mixed powder is filled into the mold of the double-wheel milling disc cutter blade 4, and is molded by a press at a pressure of 10MPa-20MPa. Specifically, the working pressure of the press can be any one of 10MPa, 12MPa, 14MPa, 16MPa, 18MPa, 20MPa, etc. When the pressure is lower than 10MPa, the mixture will not be compact enough and cannot be pressed into the shape of the cutter head. When the pressure is higher than 20MPa, the pressure of the press is too high, which increases the pressing cost of the press. Therefore, the mixture can be pressed and formed by the press at a pressure of 10MPa-20MPa.

[0048] After molding and demoulding, the blank of the blade 4 of the cutter head is placed in a vacuum sintering furnace with a vacuum degree of less than 20Pa, and slowly heated to 1450℃-1500℃ for sintering. After keeping warm for 2-3 hours, argon is introduced for hot isostatic pressing and kept warm for 1-2 hours with the argon introduction amount of 4MPa-6MPa. After being slowly cooled in the furnace, the cutter head blade 4 is obtained. Since the sintering temperature of each powder metallurgy material is different, the mixture can be sintered and formed in the temperature range of 1450℃-1500℃. When the temperature is lower than 1450℃, the strength of the mixture after sintering will be insufficient. When the temperature is higher than 1500℃, the mixture will be sintered, and the shape and size of the cutter head blade 4 after sintering will change. When the vacuum degree of the vacuum furnace is lower than 20Pa, the mixture can be prevented from being oxidized during sintering, thereby improving the sintering quality of the mixture.

[0049] After the mixture is sintered, it can be kept warm and cooled in a vacuum furnace to form a cutter blade 4, and the keeping temperature of the cutter blade 4 can be any one of 120min, 140min, 160min, and 180min. When the keeping time of the cutter blade 4 is less than 120min, the inside of the cutter blade 4 cannot be burned through, and the grains inside the cutter blade 4 are coarse and the mechanical properties are reduced. When the keeping temperature of the cutter blade 4 is higher than 180min, the keeping temperature of the cutter blade 4 is too long, resulting in too long processing and manufacturing time of the cutter blade 4.

[0050] Finally, 4MPa-6MPa argon is introduced into the vacuum furnace and hot isostatic pressing is carried out for 1-2 hours to form a certain pressure on the surface of the sintered material and gradually densify the mixture during the sintering process to improve the material strength and wear resistance. After the vacuum furnace is cooled, a TiC composite WC carbide cutter head blade 4 is obtained.

[0051] In some embodiments, in step S3, the heat treatment includes step S3.1 and step S3.2

[0052] S3.1: The blade 4 is subjected to vacuum heat treatment at a temperature between 1050℃ and 1150℃, and then air-cooled after being kept in a salt bath at a temperature of 560℃ to 600℃ for 0.5-1 hour, so as to obtain a blade 4 with a hardness of 62HRC-65HRC. Specifically, the blade 4 is subjected to vacuum heat treatment at a temperature between 1050℃ and 1150℃, which not only sintered the blade 4 (in other words, the blade blank formed by powder mixing and pressing was heated and crystallized), but also austenitized the alloy steel matrix of the blade 4, in preparation for the subsequent heat treatment. The salt bath can reduce the temperature difference between the inside and outside of the blade 4, reduce thermal stress, and reduce the deformation and cracking tendency of the blade 4. The air cooling reduces the cooling rate of the martensite transformation in the blade 4, thereby reducing the quenching stress, further preventing the deformation and cracking of the blade 4, and ensuring the processing quality of the blade 4.

[0053] S3.2: The blade 4 of the cutter head is subjected to secondary tempering at a temperature between 500°C and 600°C to obtain a hardness of 61HRC-64HRC of the blade 4 of the cutter head. Thus, the toughness of the blade 4 of the cutter head is improved by secondary tempering while maintaining its high hardness, and the final hardness is 61-64HRC.

[0054] In step S4, the carbon steel is forged at a temperature range of 850°C-1000°C to form the cutter head base body 3, and the carbon steel has a carbon content of 0.30%-0.40%. Specifically, carbon steel with a carbon content of 0.30%-0.40% is selected as the forging material, and the carbon steel is forged at a temperature range of 850°C-1000°C. Within this temperature range, the plasticity of the carbon steel can be improved, making the carbon steel easier to deform, and making it easier to form the shape of the cutter head base body 3 when forging the carbon steel.

[0055] In some embodiments, the preparation method of the double-wheel milling disc cutter head 100 also includes step S6: the cutter head blade 4 has a mounting hole extending along its width direction, the cutter head blade 4 is installed on the cutter head base 3, and is connected to the cutter head base 3 through the fastener 5 passing through the mounting hole and the fastener 5 is located in the mounting hole, a low-carbon steel gasket with a thickness of 1mm-2mm is arranged in the mounting hole and fits with the fastener 5, and then a carbide stud 6 coated with an organic adhesive is installed in the mounting hole and connected to the gasket, and it is ensured that the adhesive overflows evenly from the gap between the mounting hole and the stud 6. Specifically, a mounting hole extending in the left-right direction is provided on the blade 4 of the cutter head, a fastener 5 (for example, a screw) is passed through the mounting hole and connected to the blade base 3, a gasket is installed in the mounting hole and fits with the right end of the fastener 5, and then a carbide stud 6 coated with organic adhesive is passed through the mounting hole and the stud 6 is installed in the top hole of the gasket, and the adhesive is ensured to evenly overflow from the gap between the mounting hole and the stud 6, and then the organic adhesive flowing out of the mounting hole is scraped flat, so that the blade 4 of the cutter head is detachably mounted on the blade base 3. When disassembly is required, the blade 4 of the cutter head is heated to melt the organic adhesive on the outer surface of the stud 6, and then the stud 6, gasket and fastener 5 are removed in turn to replace the blade 4 of the cutter head.

[0056] In some embodiments, step S4 further includes step S6.1: machining the mounting seat 1, and mounting the mounting seat 1 on the milling disk hub 2, and then inserting the assembled cutter head base 3 and cutter head blade 4 into the hole of the cutter head mounting seat 1, first spot welding and fixing, and then full welding the joint between the cutter head base 3 and the mounting seat 1. Thus, the cutter head base 3 and the cutter head blade 4 are mounted on the hub 2 through the mounting seat 1.

[0057] Since the cutter head base 3 contacts the soil layer and wears out during the construction of the double-wheel milling disc cutter head 100, in order to improve the service life of the cutter head base 3, in some embodiments, the cutter head base 3 and the double-wheel milling disc cutter head 100 preparation method further include step S7: after preheating the cutter head base 3 to 250℃-270℃, spray-welding a 1-2mm self-fluxing alloy wear-resistant layer on the surface of the cutter head base 3. Specifically, Figure 1-2 As shown, preheating the cutter head base 3 between 250℃-270℃ is not only beneficial to reduce the welding stress between the cutter head base 3 and the mounting seat 1, but also improves the bonding strength between the spray-welded wear-resistant layer and the cutter head base 3. When the preheating temperature is less than 250℃, the preheating temperature is too low, and the stress reduction effect in the cutter head base 3 is not obvious. When the preheating temperature is greater than 270℃, the preheating temperature is too high, which will cause a hardened layer to form at the welded joint, resulting in cracking, that is, the spray-welded layer is not firmly bonded. Therefore, the cutter head base 3 can improve the service life and wear resistance of the cutter head base 3 by spraying a 1-2mm self-fluxing alloy wear-resistant layer on the surface of the cutter head base 3.

[0058] The following is a detailed description of the method for preparing a double-wheel milling disc cutter head according to an embodiment of the present invention:

[0059] S1. Mix 200-350 mesh TiC powder, WC powder and alloy steel powder with a binder in a mixer to obtain a mixed powder, wherein the mass content of TiC powder is 35-45%; the mass content of WC powder is 5-10%; the mass ratio of alloy steel powder is: C: 0.9-1.1%, Mn: 1.0-1.5%, Ni: 2.5-3.5%, Mo: 2.5-3.0%, Ti: 0.5-1.0%; V: 1.5-2.0%, Nb: 0.5-1.0%, the balance is iron, and the binder is 4-8%, and the binder is polyvinyl alcohol and paraffin;

[0060] S2, filling the mixed powder into the double-wheel milling disc cutter head blade 4 mold, and molding it under a press pressure of 10-20MPa, and the binder is polyvinyl alcohol and paraffin, and the chamfer radius of the blade edge of the cutter head blade 4 is 1-2mm;

[0061] S3, after forming and demolding, the blank of the blade 4 of the cutter head is placed in a vacuum sintering furnace, slowly heated to 1450°C-1500°C for sintering, kept warm for 2-3 hours, and then introduced with argon for hot isostatic pressing and kept warm for 1-2 hours, and then slowly cooled with the furnace to obtain the TiC composite WC hard alloy cutter head blade 4, and the amount of argon introduced is 4MPa-6MPa;

[0062] S4, subjecting the blade 4 of the cutter head in S3 to vacuum heat treatment at 1050-1150° C. and a vacuum degree of less than 20 Pa, and then placing it in a salt bath at 560-600° C. and keeping it for 0.5-1 hour, and then air cooling it to obtain a double-wheel milling disc cutter head blade 4 with a hardness of 62-65 HRC;

[0063] S5, performing secondary tempering on the cutter head edge portion 4 in S4 at a secondary tempering temperature of 500° C.-600° C., to obtain a double-wheel milling disc cutter head edge portion 4 having a hardness of 61-64 HRC;

[0064] S6, select medium carbon steel forgings as the material of the cutter head base 3 and the carbon content of the carbon steel is 0.30%-0.40%, the forging temperature range is 1000-850°C, and then, after quenching and tempering treatment and machining, the cutter head base 3 is obtained, and the obtained cutter head base 3 has a process hole 31 of φ10-φ15 in the middle and one end of the cutter head base 3 is designed as a step structure;

[0065] S7, install the blade 4 on the blade base 3 and fix it with a fastener 5, place a 1-2mm low-carbon steel gasket on the top of the fastener 5, and then install the carbide stud 6 coated with organic adhesive in the top hole of the gasket, and ensure that the adhesive overflows evenly from the gap, and then scrape it flat. The gasket is made of aluminum alloy or low-carbon steel, etc., in order to prevent the organic adhesive from penetrating into the bolt head and to isolate the adhesive for the purpose of bolt removal. The composition and preparation process of the carbide stud 6 are the same as those of the blade 4;

[0066] S8, machining the cutter head mounting seat 1, setting a single-sided V-shaped groove on the cutter head mounting seat 1, and mounting it on the milling disc hub 2, and then installing the assembled double-wheel milling disc cutter head 100 into the hole of the cutter head mounting seat 1, first spot welding it, and then fully welding the joint between the cutter head base 3 and the cutter head mounting seat 1;

[0067] S9. After preheating the cutter head to 250-270° C., a 1-2 mm self-fluxing alloy wear-resistant layer is spray-welded on the surface of the cutter head base 3 to obtain a low-cost, repairable double-wheel milling disc cutter head 100, wherein the self-fluxing alloy is an iron-based self-fluxing alloy.

[0068] The beneficial effects of the present invention are as follows:

[0069] (1) The cutting edge 4 of the double-wheel milling disc cutter head is made of wear-resistant material containing TiC and WC hard alloy, and its service life is more than 5 times that of high manganese steel or high-speed steel, which reduces the downtime for cutting head replacement by more than 4 times and improves milling efficiency;

[0070] (2) Compared with pure tungsten carbide cutter heads, only the cutter head edge 4 is made of cemented carbide material, which greatly reduces the cost of the cutter head;

[0071] (3) When the double-wheel milling disc cutter blade 4 is milling hard rock, the local temperature is too high, which will cause the hardness of the cutter blade 4 to decrease. The cutter blade 4 contains alloy elements such as V, Nb, Ti, and Mo, which can improve the red hardness of the cutter, that is, the cutter still maintains a high hardness at high temperatures, thereby increasing the service life of the cutter blade 4;

[0072] (4) During the vacuum sintering process of the blade 4, hot isostatic pressing is used to greatly improve the density of the blade 4 and extend its service life. The blade 4 is subjected to vacuum heat treatment to reduce material oxidation and decarburization, thereby improving the milling performance of the blade 4;

[0073] (5) After the blade 4 of the cutter head is worn, the organic adhesive can be rendered ineffective by heating, and then the carbide studs 6 and gaskets can be removed, the bolts can be removed, and a new blade 4 of the cutter head can be reinstalled, thereby achieving the repairability of the cutter head;

[0074] (6) The stepped structure design at one end of the cutter head base 3 can give full play to the supporting role of the cutter head base 3 on the cutter head cutting edge 4 during the milling process, thereby preventing the cutter head cutting edge 4 from breaking due to a large cutting force;

[0075] (7) The cutter head base 3 is made of medium carbon steel forgings, which can ensure its strong comprehensive mechanical properties. The process hole 31 of the cutter head base 3 is mainly used to reduce the welding stress during the welding process and prevent the cutter head base 3 from deformation and cracking;

[0076] (8) A self-fluxing alloy wear-resistant layer is spray-welded on the surface of the cutter head base 3 to reduce the wear of the cutter head base 3 and extend its service life.

[0077] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0078] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0079] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0080] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0081] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0082] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A double-wheel milling disc cutter head, characterized in that: include: A mounting seat, the mounting seat being suitable for being arranged on the outer peripheral side of the wheel hub; A cutter head base, the cutter head base comprising a first part and a second part connected to each other, the first part is arranged in the mounting seat, the second part is located outside the mounting groove, and one side of the second part is provided with a mounting groove penetrating the second part along the length direction of the mounting seat; The blade of the cutter head is made of TiC, WC and alloy steel and is detachably mounted in a mounting groove on the back of the cutter head base body so as to facilitate replacement of the blade of the cutter head when the blade of the cutter head is worn.

2. The double-wheel milling disc cutter head according to claim 1, characterized in that: Also includes: A fastener, wherein the blade portion of the cutter head is provided with a mounting hole extending in the width direction of the mounting seat, and the fastener is inserted into the mounting hole and into the second part, so that the blade portion of the cutter head is detachably connected to the second part through the fastener; A column nail, the outer peripheral surface of which is coated with organic glue and is inserted into the mounting hole and is located on a side of the fastener away from the second part; A gasket is disposed in the mounting hole and between the fastener and the stud.

3. The double wheel milling disc cutter head according to claim 1, characterized in that: The outer peripheral surface of the cutter head base is coated with a self-fluxing alloy wear-resistant layer.

4. A method for preparing a double-wheel milling disc cutter head, characterized in that: include: S1: Mix 200-350 mesh TiC powder, WC powder, alloy steel powder and binder to obtain a mixed powder. S2: pressing the mixed powder into a shape of a blade portion of a cutter head, and then sintering the pressed mixed powder into the blade portion of the cutter head; S3: heat-treating the sintered blade portion of the tool head so that the hardness of the blade portion of the tool head is 61HRC-64HRC. S4: Selecting a carbon steel forging as a cutter head substrate, and heat treating the cutter head substrate to improve the toughness of the cutter head substrate; S5: The cutting edge of the cutter head is detachably mounted on the cutter head base.

5. The method for preparing a double-wheel milling disc cutter head according to claim 4, characterized in that: In step S1, the content of the TiC powder is 35%-45%, the content of the WC powder is 5%-10%, the content of the binder is 4%-8%, and the alloy steel powder includes 0.9%-1.1% C, 1.0%-1.5% Mn, 2.5%-3.5% Ni, 2.5%-3.0% Mo, 0.5%-1.0% Ti, 1.5%-2.0% V, 0.5%-1.0% Nb, and the balance is iron.

6. The method for preparing a double-wheel milling disc cutter head according to claim 4, characterized in that: In step S2, the mixed powder is filled into a double-wheel milling disc cutter head blade mold and molded using a press at a pressure of 10MPa-20MPa. After forming and demolding, the blank of the blade is placed in a vacuum sintering furnace with a vacuum degree of less than 20Pa, slowly heated to 1450℃-1500℃ for sintering, and kept warm for 2-3 hours. Then, argon is introduced for hot isostatic pressing and kept warm for 1-2 hours with an argon introduction amount of 4MPa-6MPa. After slowly cooling in the furnace, the blade is taken out of the furnace.

7. The method for preparing a double-wheel milling disc cutter head according to claim 4, characterized in that: In step S3, the heat treatment comprises: S3.1: The blade of the cutter head is subjected to vacuum heat treatment at a temperature between 1050°C and 1150°C, and then kept in a salt bath at a temperature between 560°C and 600°C for 0.5 to 1 hour and then air-cooled to obtain a blade of the cutter head with a hardness of 62HRC to 65HRC; S3.2: The cutting edge of the cutter head is subjected to secondary tempering at a temperature between 500°C and 600°C to obtain a cutting edge of the cutter head having a hardness of 61HRC to 64HRC.

8. The method for preparing a double-wheel milling disc cutter head according to claim 4, characterized in that: In step S4, the carbon steel is forged at a temperature ranging from 850° C. to 1000° C. to form a cutter head substrate, wherein the carbon content of the carbon steel is 0.30% to 0.40%.

9. The method for preparing a double-wheel milling disc cutter head according to any one of claims 4 to 8, characterized in that: The step S6 is also included: The blade of the cutter head has a mounting hole extending along its width direction. The blade of the cutter head is mounted on the cutter head base and connected to the cutter head base through a fastener passing through the mounting hole and the fastener is located in the mounting hole. A low-carbon steel gasket with a thickness of 1mm-2mm is arranged in the mounting hole and fits with the fastener. A carbide stud coated with an organic adhesive is then installed in the mounting hole and connected to the gasket, and it is ensured that the adhesive overflows evenly from the gap between the mounting hole and the stud.

10. The method for preparing a double-wheel milling disc cutter head according to claim 9, characterized in that: The method further comprises step S7: after preheating the cutter head substrate to 250° C.-270° C., spray-welding a 1-2 mm self-fluxing alloy wear-resistant layer on the surface of the cutter head substrate.

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