Pickaxe-shaped coal cutting tooth cutter for coal mining tunneling

Abstract

The invention discloses a pickaxe type coal cutting tooth cutter for coal mining tunneling, and relates to the technical field of coal mining equipment, the pickaxe type coal cutting tooth cutter comprises a cutting tooth body and an alloy head fixed at the front end of the cutting tooth body, the side wall of the cutting tooth body is provided with alloy beans, the outer surface of the alloy head is provided with a first conical surface and a second conical surface which are in integral transition, and the first conical surface and the second conical surface are arranged in parallel. The second conical surface is in butt joint with the front end of the cutting pick body, and the outer diameter of the second conical surface in the extending direction of the first conical surface is gradually reduced; the outer side wall of the first conical surface and the outer side wall of the second conical surface are each provided with a plurality of evenly-distributed reinforcing teeth, and the reinforcing teeth are convex curved surface bodies with the surface curvature continuously changing. The first conical surface and the second conical surface which are in integral transition are formed on the outer surface of the alloy head, the reinforcing teeth are uniformly distributed on the outer side wall, and the alloy head is formed by adding the reinforcing tooth structure in the design of the alloy head, performing compression molding by adopting a mold and performing pressure sintering, so that the rock cutting and breaking efficiency of a cutter is enhanced, and the extra cutting life is provided.

Description

Technical Field

[0001] The present invention relates to the technical field of coal mining equipment, and more particularly to a pick-shaped coal cutting tooth tool used for coal mining and excavation. Background Art

[0002] Coal mining and tunneling are important links in the coal mining process, and coal cutter tools are key components of coal mining and tunneling equipment, and their performance directly affects coal mining efficiency and cost; coal cutter tools used for coal mining and tunneling are usually composed of a cutter body and an alloy head. The design of the alloy head and its reinforced structure directly affects the wear resistance and impact resistance of the tool.

[0003] Traditional alloy heads are generally prismatic or frustum-shaped. For example, the Chinese patent document with publication number CN204082144U discloses a wear-resistant cutting pick for a tunnel boring machine, including a pick shank, a tooth shoulder, a pick head and an alloy head, wherein the alloy head is arranged in a blind hole at the center of the front end of the pick head, and a diamond layer is provided at one end of the alloy head located outside the blind hole. The alloy head is in the shape of a quadrangular pyramid at one end located outside the blind hole, and a number of reinforced teeth are symmetrically provided at the top of the pick head. Although this technical solution improves the wear resistance to a certain extent, the strip-shaped reinforced teeth have sharp edges, which leads to local stress concentration when cutting hard rock, easily strengthening the initiation of microcracks at the tooth root, and expanding into through-fractures under cyclic loads; at the same time, the alloy head adopts a quadrangular pyramid design, and its rock breaking process relies on the line contact cutting of the four edges to break the rock, which can easily cause edge blunting and tip chipping, affecting work efficiency.

[0004] Therefore, how to provide a coal cutting tool that can eliminate stress concentration, achieve efficient rock breaking and has strong adaptability to working conditions is a problem that technical personnel in this field urgently need to solve. Summary of the Invention

[0005] In view of this, the present invention provides a pick-shaped coal cutting tooth tool used in coal mining and excavation, aiming to solve the above technical problems.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A pick-type coal cutting tool used in coal mining and excavation, comprising a cutting tooth body and an alloy head fixed to the front end of the cutting tooth body, the side wall of the cutting tooth body having an alloy bean, the outer surface of the alloy head forming a first conical surface and a second conical surface with an integral transition, the second conical surface docking with the front end of the cutting tooth body, and the outer diameter of the second conical surface gradually decreasing in the extension direction of the first conical surface; the outer side walls of the first conical surface and the second conical surface are each provided with a plurality of evenly distributed reinforcing teeth, the reinforcing teeth being a convex surface body with a continuously changing surface curvature.

[0008] Through the above technical solution, the outer surface of the alloy head of the present invention forms a first conical surface and a second conical surface with an integral transition, and reinforced teeth are evenly distributed on the outer wall. By adding a reinforced tooth structure to the alloy head design, it is formed by mold pressing and pressure sintering, which enhances the cutting and rock breaking efficiency of the tool and provides additional cutting life; this design enables the tool to better disperse stress during the cutting process and eliminate stress concentration on the edges; thereby improving the wear resistance and impact resistance of the tool; the design of the reinforced teeth changes the original single-point rock breaking into multi-point rock breaking, thereby improving rock breaking efficiency, reducing equipment power consumption, and improving processing vibration; the reinforced teeth are convex surfaces with continuously changing surface curvature. This shape design can better adapt to changes in the hardness of the coal seam and enhance the rock breaking efficiency of the tool; the side walls of the pick body are provided with alloy beans, which further enhance the wear resistance of the pick body and extend the service life of the tool.

[0009] Preferably, in the aforementioned pick-shaped coal cutting tool used in coal mining and tunneling, the second conical surface has a greater taper than the first conical surface, and the second conical surface is a frustum-shaped structure, while the first conical surface is a cone-shaped structure. This design makes the alloy head more stable, better able to withstand cutting and impact forces; the frustum-shaped second conical surface can better guide coal dust discharge, reduce resistance during cutting, and thus improve cutting efficiency.

[0010] Preferably, in the aforementioned pick-shaped coal cutting tool used in coal mining and tunneling, the reinforced teeth are spherical crown protrusions, elliptical protrusions, or teardrop protrusions, and the reinforced teeth on the first and second conical surfaces are one or a combination of at least two different forms of the spherical crown protrusions, the elliptical protrusions, or the teardrop protrusions. The diverse reinforced tooth designs can better adapt to coal seams of varying hardness and texture, improving the tool's versatility and adaptability. The continuously changing curved surface disperses local loads and inhibits crack formation. The different forms of reinforced teeth can further optimize stress distribution, reduce local stress concentration, and thus improve the tool's fatigue resistance.

[0011] Preferably, in the aforementioned pick-shaped coal cutting tool used in coal mining and tunneling, 4-8 of the reinforcing teeth are fixed to both the first and second conical surfaces. This structural design ensures tool strength while avoiding the added weight of an excessive number of reinforcing teeth, thereby maintaining the tool's lightness and flexibility. The even distribution of the reinforcing teeth further optimizes stress distribution and improves the tool's overall performance.

[0012] Preferably, in the aforementioned pick-type coal cutter used in coal mining and excavation, the outer wall of the cutter body has at least two spaced-apart chip flutes, with the alloy bean located between two adjacent chip flutes. The provision of multiple chip flutes effectively reduces machining vibration and significantly improves the tool's chip removal efficiency, resolving the problem of high vibration and poor chip removal associated with existing tools. The chip flute design effectively guides coal dust removal, avoiding chip blockage caused by an excessive number of teeth, thereby improving cutting efficiency. The location of the alloy bean between two adjacent chip flutes further enhances the wear resistance of the cutter body and extends the tool's service life.

[0013] Preferably, in the above-mentioned pick-shaped coal cutting tool for coal mining and excavation, the number of the chip flutes is 2-8. This number range balances strength and chip removal space.

[0014] Preferably, in the aforementioned pick-shaped coal cutting tool used in coal mining and excavation, the chip flute is a spiral flute with a variable cross-section. This design can accelerate the flow of coal chips, reduce adhesion and vibration, lower energy consumption, better guide the discharge of coal chips, and reduce accumulation and blockage of coal chips during the cutting process. The spiral chip flute design can also make the tool more stable during cutting, reduce vibration, and improve cutting accuracy.

[0015] Preferably, in the above-mentioned pick-shaped coal cutter tool used in coal mining and excavation, the chip removal groove extends from the front edge of the pick body to the surface of the pick body. This further optimizes the chip removal path, ensures that coal chips are quickly discharged from the cutting point, prevents accumulation and wear on the tool, and improves chip removal efficiency; reduces resistance during the cutting process, thereby improving cutting efficiency and reducing energy consumption.

[0016] Preferably, in the aforementioned pick-shaped coal cutter tool used in coal mining and tunneling, the number of alloy beans is 10-18, and they are evenly distributed between two adjacent chip flutes. This further enhances the wear resistance of the pick body and extends the tool's service life. The even distribution of alloy beans optimizes stress distribution, reduces local stress concentration, and improves the tool's fatigue resistance.

[0017] Preferably, in the aforementioned pick-shaped coal cutting tool used in coal mining and tunneling, the alloy bean is a spherical crown. Spherical crown alloy beans lack sharp edges and corners, thus avoiding stress concentration-induced fracture and failure, better withstanding impact forces and enhancing the tool's impact resistance. This further enhances the wear resistance of the cutter body and prolongs the tool's service life.

[0018] It can be seen from the above technical solution that, compared with the prior art, the present invention discloses a pick-shaped coal cutting tool for coal mining and excavation, which has the following beneficial effects:

[0019] 1. The present invention significantly improves the wear resistance and impact resistance by optimizing the design of the alloy head and the pick body; the alloy head adopts a double-conical surface structure, and reinforced teeth with continuously changing surface curvature are evenly distributed on the first and second conical surfaces. This design can effectively disperse the cutting force and avoid stress concentration, thereby significantly improving the wear resistance and impact resistance of the tool; at the same time, the alloy beans on the side wall of the pick body further enhance the wear resistance and extend the service life of the tool.

[0020] 2. The present invention provides multiple spiral chip grooves on the outer wall of the pick body, and the chip grooves have a variable cross-section structure, which can effectively guide the coal chips to be discharged quickly and avoid the accumulation of coal chips, thereby improving cutting efficiency, reducing cutting resistance and reducing energy consumption; in addition, the double-conical surface structure of the alloy head makes the tool more evenly stressed during the cutting process, can better adapt to coal seams of different hardness, and further improve rock breaking efficiency.

[0021] 3. The multiple chip flutes and dual-cone structure of the alloy head ensure a more even force distribution during cutting, reducing vibration and noise. The spiral chip flute design further optimizes the chip removal path, reducing dust accumulation and further reducing vibration and noise during cutting.

[0022] 4. The reinforcing teeth of this invention can feature one or more combinations of spherical crown protrusions, elliptical protrusions, or teardrop protrusions. This diverse design allows for better adaptation to coal seams of varying hardness and texture, enhancing the tool's versatility and adaptability. Furthermore, the alloy head and pick body are connected using an interference fit and hot pressing method, avoiding the heat-affected zone and material degradation associated with traditional welding, thereby improving joint strength and service life.

[0023] 5. The pick-type coal cutting tooth tool for coal mining and excavation of the present invention has been significantly improved in terms of wear resistance, impact resistance, cutting efficiency, chip removal performance, service life, etc. These improvements enable the tool to better meet the needs of complex coal mining and excavation conditions, improve coal mining efficiency, and reduce coal mining costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0025] Figure 1 The accompanying drawing is a front view of a pick-shaped coal cutting tool for coal mining and excavation provided by the present invention (with a water drop protrusion + a water drop protrusion combined alloy head and six chip removal grooves);

[0026] Figure 2 Attached photos Figure 1 a top view of the accompanying drawing;

[0027] Figure 3 The accompanying drawing is an exploded view of a pick-shaped coal cutting tool used in coal mining and excavation provided by the present invention;

[0028] Figure 4 The accompanying drawing is a front view of a pick-shaped coal cutting tool for coal mining and excavation provided by the present invention (an alloy head with an elliptical protrusion + an elliptical protrusion combination and six chip removal grooves);

[0029] Figure 5 The attached picture is Figure 4 a top view of the accompanying drawing;

[0030] Figure 6 The accompanying drawing is a front view of a pick-shaped coal cutting tool for coal mining and excavation provided by the present invention (a combined alloy head with a spherical crown protrusion and an elliptical protrusion and six chip removal grooves);

[0031] Figure 7 The attached picture is Figure 6 a top view of the accompanying drawing;

[0032] Figure 8 The accompanying drawing is a front view of a pick-shaped coal cutting tool for coal mining and excavation provided by the present invention (water drop protrusion + elliptical protrusion, five chip removal grooves);

[0033] Figure 9 The attached picture is Figure 8 a top view of the accompanying drawing;

[0034] Figure 10 The accompanying drawing is a front view of a pick-shaped coal cutting tool for coal mining and excavation provided by the present invention (water drop protrusion + elliptical protrusion, four chip removal grooves);

[0035] Figure 11 The attached picture is Figure 10 a top view of the accompanying drawing;

[0036] Figure 12 The accompanying drawing is a front view of a pick-shaped coal cutting tool used for coal mining and excavation provided by the present invention (water drop protrusion + elliptical protrusion, three chip removal grooves);

[0037] Figure 13 The attached picture is Figure 12 a top view of the accompanying drawing;

[0038] Figure 14 The accompanying drawing is a front view of a pick-shaped coal cutting tool for coal mining and excavation provided by the present invention (water drop protrusion + elliptical protrusion, two chip removal grooves);

[0039] Figure 15 The attached picture is Figure 14 Top view of the accompanying drawing.

[0040] in:

[0041] 1-cutting tool body; 11-mounting groove; 2-alloy head; 21-first cone surface; 22-second cone surface; 3-alloy bean; 4-reinforced tooth; 5-chip groove. DETAILED DESCRIPTION

[0042] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0043] See attached Figure 1-3 The embodiment of the present invention discloses a pick-type coal cutting tool for coal mining and tunneling, including a cutting tool body 1 and an alloy head 2 fixed to the front end of the cutting tool body 1. The side wall of the cutting tool body 1 is provided with an alloy bean 3. The outer surface of the alloy head 2 is formed with a first conical surface 21 and a second conical surface 22 with an integral transition. The second conical surface 22 is connected to the front end of the cutting tool body 1, and the outer diameter of the second conical surface 22 gradually decreases in the extension direction of the first conical surface 21; the outer side walls of the first conical surface 21 and the second conical surface 22 are provided with a plurality of evenly distributed reinforcing teeth 4, and the reinforcing teeth 4 are convex curved surfaces with continuously changing surface curvature.

[0044] In order to further optimize the above technical solution, the pick body 1 is made of alloy steel and is subjected to boronizing treatment to form a gradient wear-resistant layer, and the surface boronizing treatment thickness is 0.2-0.6mm; by boronizing the pick body 1 to form a gradient wear-resistant layer, the surface hardness is made greater than HRC70, while maintaining the internal toughness of the steel body, effectively improving the wear resistance of the steel body, and solving the problem of insufficient wear resistance of the existing pick body.

[0045] In order to further optimize the above technical solution, the alloy head 2 and the pick body 1 are connected by interference fit hot pressing. By connecting the alloy head 2 and the pick body 1 by interference fit hot pressing, the bonding force between the alloy head 2 and the pick body 1 is ensured, and the problem of decreased tool body strength caused by the inlay welding process is avoided. At the same time, by reducing the amount of precious metals used in the brazing process, the manufacturing cost of the tool is effectively reduced, solving the problem of high cost of existing tools.

[0046] In order to further optimize the above technical solution, the alloy head adopts WC-10% Co material, and adds 2% Cr3C2 and 1% VC to ensure the strength of the tool while reducing the possibility of sparks during excavation; by adding 2% Cr3C2 and 1% VC in the alloy head 2, the grain growth is effectively inhibited, the impact resistance of the alloy head 2 is improved, and the problem of weak impact resistance of the existing tool alloy head is solved.

[0047] In order to further optimize the above technical solution, the alloy bean is made of WC-8% Co and is connected to the pick body 1 by brazing.

[0048] In order to further optimize the above technical solution, the taper of the second tapered surface 22 is greater than that of the first tapered surface 21 , the second tapered surface 22 is a frustum structure, and the first tapered surface 21 is a cone structure.

[0049] In order to further optimize the above technical solution, the reinforcing teeth 4 are spherical crown protrusions, elliptical protrusions, or water drop protrusions; and the reinforcing teeth 4 on the first conical surface 21 and the second conical surface 22 are one of the spherical crown protrusions, elliptical protrusions, or water drop protrusions, or a combination of at least two different forms.

[0050] In order to further optimize the above technical solution, 4-8 reinforcing teeth 4 are fixed on the first conical surface 21 and the second conical surface 22 .

[0051] In order to further optimize the above technical solution, at least two spaced-apart chip removal grooves 5 are provided on the outer side wall of the pick body 1 , and the alloy bean 3 is located between two adjacent chip removal grooves 5 .

[0052] In order to further optimize the above technical solution, the number of the chip removal grooves 5 is 2-8.

[0053] In order to further optimize the above technical solution, the chip groove 5 is a spiral chip groove, and its cross section is a variable cross-section structure.

[0054] In order to further optimize the above technical solution, the chip groove 5 adopts a structure combining straight lines, arcs and curves, and the chip groove 5 is a variable cross-section structure, that is, the structural dimensions of each cross section of the chip groove 5 are different.

[0055] In order to further optimize the above technical solution, the chip removal groove 5 extends from the front edge of the pick body 1 to the surface of the pick body 1.

[0056] In order to further optimize the above technical solution, the number of the alloy beans 3 is 10-18, and they are evenly distributed between two adjacent chip grooves 5.

[0057] In order to further optimize the above technical solution, the alloy bean 3 is a spherical crown.

[0058] During the coal mining and excavation process, the pick-type coal cutting tooth tool of the present invention is installed on the drum of the coal mining machine. As the drum rotates, the cutting edge of the alloy head 2 cuts the coal seam; since the alloy head 2 adopts a double-conical surface structure, its first conical surface 21 and the second conical surface 22 are evenly distributed with reinforced teeth 4. These reinforced teeth 4 can effectively disperse the cutting force during the cutting process and avoid stress concentration, thereby improving the impact resistance and wear resistance of the tool. At the same time, the different forms of the reinforcing teeth 4 (spherical crown protrusions, elliptical protrusions, and water drop protrusions) can better adapt to the hardness changes of the coal seam and enhance the rock breaking efficiency of the tool; a spiral chip groove 5 is provided on the outer wall of the pick body 1, and its cross section is a variable cross-section structure, and the chip groove 5 extends from the front edge of the pick body 1 to the surface of the pick body 1; this design allows the coal dust generated during the cutting process to be quickly discharged along the chip groove 5, avoiding the impact of coal dust accumulation on cutting efficiency, while also reducing vibration and noise; in addition, there are alloy beans 3 on the side wall of the pick body 1, and the alloy beans 3 are spherical crowns, and there are multiple alloy beans, which are evenly distributed between two adjacent chip grooves 5; the setting of the alloy beans 3 further enhances the wear resistance and impact resistance of the pick body 1, and extends the service life of the tool. Through this structural setting, the present invention solves the technical problems of poor wear resistance, short service life, and poor chip removal effect of existing coal cutter tools, improves the cutting performance and service life of the tool, and is suitable for the coal cutting process in coal mining operations.

[0059] See attached Figure 1-15 , which is a diagram illustrating the layout of different numbers of chip flutes 5, different combinations of reinforcing teeth 4 and different numbers of alloy beans 3. The following is an example description of a specific embodiment.

[0060] Example 1:

[0061] The present embodiment provides a pick-type coal cutting tool for coal mining and excavation, including a cutting tooth body 1 and an alloy head 2. The alloy head 2 is connected to the cutting tooth body 1 by interference fit and hot pressing. The cutting tooth body 1 has a brazed alloy bean 3 and a chip groove 5. The chip groove 5 adopts a three-edge structure, and the alloy head 2 has reinforced teeth 4.

[0062] The pick body 1 is made of 45CrNiMoV alloy steel, with an overall length of 147.4mm and a diameter of 37.6mm. A mounting recess 11 for the alloy head 2 is provided at the front end of the pick body 1. The recess 11 is 20mm deep and 24mm in diameter. The surface of the pick body 1 is provided with a chip flute 5 with a depth of 2-5mm and a width of 4-10mm. The spiral chip flute 5 extends along the surface of the pick body 1, starting from the connection point of the alloy head 2.

[0063] The pick body 1 is equipped with an alloy bead 3. Made from a high-hardness alloy material with a hardness of HRC 90-92, the bead 3 is spherically shaped, with a diameter of 3-6mm and a height of 2-5mm. Fifteen alloy bead 3s are welded to the front surface of the pick body 1, with spacing of approximately 2-12mm between them. The spherical bean design enhances impact resistance, further improving the wear resistance and service life of the pick body 1.

[0064] The alloy head 2 is made of tungsten-cobalt cemented carbide with 5% rare earth elements added, achieving a hardness of HRA94 or higher and a bending strength of no less than 2200 MPa. The alloy head 2 has a double-conical structure, is 28 mm long, has a bottom diameter of 24 mm, and has a circular cutting edge at the top.

[0065] The reinforced teeth 4 of the alloy head 2 are designed on the double-conical surface of the alloy head 2. The first conical surface 21 is designed with six elliptical raised teeth 4, and the second conical surface 22 is designed with seven elliptical raised teeth 4. Each tooth 4 has a raised height of 1-4mm and is molded integrally from the same material as the alloy head 2. The design of the reinforced teeth 4 further enhances the strength and rigidity of the alloy head 2, improving the tool's rock-breaking ability and enabling it to withstand extreme impact loads and cutting forces, making it suitable for coal cutting operations in hard coal seams.

[0066] The alloy head 2 is connected to the pick body 1 using an interference fit hot pressing method. The specific connection method involves heating the pick body 1 to 290°C, temporarily expanding the diameter of the mounting groove 11 by approximately 0.07mm. Simultaneously, the alloy head 2 is cooled to -50°C, temporarily contracting its diameter by approximately 0.05mm. The alloy head 2 is then quickly inserted into the mounting groove 11 of the pick body 1. A pressure of 30 tons is applied for 40 seconds. Once the temperature returns to normal, the alloy head 2 and the pick body 1 form an extremely secure interference fit.

[0067] In actual use, the pick-type coal cutting tooth tool of this embodiment is installed on the drum of a coal mining machine, and the rotation of the drum drives the tool to cut the coal seam; the chip groove 5 is designed to quickly discharge coal chips, avoiding the impact of coal chip accumulation on cutting efficiency; the multi-groove structure design ensures that the tool is evenly stressed during the cutting process, reducing vibration and noise, and improving cutting efficiency; the reinforced tooth 4 structure of the alloy head 2 enhances the tool's rock breaking efficiency, wear resistance, and cutting efficiency, making the tool longer-lasting and more efficient. The use of an interference fit hot pressing connection method significantly improves the reliability and durability of the connection between the alloy head 2 and the pick body 1.

[0068] After practical application testing at a hard coal mine, the pick-shaped coal cutting tool of this embodiment has shown an approximately 40% increase in service life, a 25% increase in coal cutting efficiency, and a 30% reduction in vibration and noise compared to conventional tools. This tool exhibits improved stability and durability, particularly when cutting coal in hard coal seams.

[0069] Example 2:

[0070] The present embodiment provides a pick-type coal cutting tool for coal mining and excavation, including a cutting tool body 1 and an alloy head 2. The alloy head 2 is connected to the cutting tool body 1 by interference fit and hot pressing. The cutting tool body 1 has a brazed alloy bean 3 and a chip groove 5. The chip groove 5 has a four-edge structure. The alloy head 2 has reinforced teeth 4.

[0071] The pick body 1 is made of 42CrMo alloy steel, with an overall length of 152mm and a diameter of 37.6mm. A mounting recess 11 is provided at the front end for mounting the alloy head 2. This recess 11 is 15mm deep and 18mm in diameter. A chip flute 5 is provided on the surface of the pick body 1, extending from the point where the alloy head 2 is connected and along the surface of the pick body 1.

[0072] The pick body 1 is equipped with alloy beads 3. Made from a high-hardness alloy with a hardness of HRC90-92, these beads are spherical, with a diameter of 3-6mm and a height of 2-5mm. They are welded to the surface of the pick body 1. Sixteen beads 3 are provided, spaced 3-10mm apart.

[0073] The alloy head 2 is made of tungsten-cobalt cemented carbide material with a hardness of HRA92 or higher and a bending strength of not less than 2000 MPa. The alloy head 2 has a double-conical structure with a length of 24 mm, a bottom diameter of 18 mm, and a circular cutting edge at the top.

[0074] The reinforced teeth 4 of the alloy head 2 are designed on the double-conical surface of the alloy head 2. The first conical surface 21 is designed with six spherical-shaped reinforced teeth 4, and the second conical surface 22 is designed with seven elliptical-shaped reinforced teeth 4. The height is 0.5-1.5mm and they are molded in one piece from the same material as the alloy head 2. The design of the reinforced teeth 4 further enhances the tool's rock-breaking ability and increases the strength and rigidity of the alloy head 2, enabling the tool to withstand greater impact loads and cutting forces.

[0075] The alloy head 2 is connected to the pick body 1 using an interference fit hot pressing method. The specific connection method involves heating the pick body 1 to 270°C, temporarily expanding the diameter of the mounting groove 11 by approximately 0.06mm. Simultaneously, the alloy head 2 is cooled to -40°C, temporarily contracting its diameter by approximately 0.04mm. The alloy head 2 is then quickly inserted into the mounting groove 11 of the pick body 1. A pressure of 25 tons is applied for 35 seconds. Once the temperature returns to normal, a secure interference fit is formed between the alloy head 2 and the pick body 1.

[0076] After practical application testing at a coal mine, the four-edge pick-shaped coal cutter of this embodiment improved cutting efficiency by approximately 15% and reduced vibration and noise by approximately 10% compared to the three-edge structure of Example 1. The four-edge structure exhibited greater stability and adaptability, particularly in coal cutting operations under complex geological conditions.

[0077] Example 3:

[0078] The present embodiment provides a pick-type coal cutting tool for coal mining and excavation, including a cutting tool body 1 and an alloy head 2. The alloy head 2 is connected to the cutting tool body 1 by interference fit and hot pressing. The cutting tool body 1 has a brazed alloy bean 3 and a chip groove 5. The chip groove 5 has a six-blade structure. The alloy head 2 has reinforced teeth 4.

[0079] The pick body 1 is made of 40CrNiMo alloy steel, with an overall length of 165mm and a diameter of 37.6mm. A mounting recess 11 is provided at the front end for the alloy head 2. This recess 11 is 15mm deep and 18mm in diameter. A chip groove 5 is provided on the surface of the pick body 1, extending from the connection point with the alloy head 2 and along the surface of the pick body 1. The design of the chip groove 5 allows for the rapid discharge of coal dust generated during the coal cutting process, preventing dust accumulation that could affect cutting efficiency and cause vibration.

[0080] The pick body 1 is equipped with alloy beads 3. Made from a high-hardness alloy with a hardness of HRC 85-87, these beads are spherical with a diameter of 2-6mm and a height of 2-5mm. Twelve beads 3 are welded to the pick body 1, spaced 3-12mm apart. This arrangement enhances the wear resistance of the pick body 1 and extends the tool's service life.

[0081] The alloy head 2 is made of tungsten-cobalt cemented carbide with a hardness of HRA88 or higher and a bending strength of no less than 1800MPa. The alloy head 2 has a double-conical structure, with a length of 20mm, a bottom diameter of 18mm, and a circular cutting edge at the top. The reinforced teeth 4 of the alloy head 2 are designed on the double-conical surface of the alloy head 2. The first conical surface 21 is designed with six reinforced teeth 4 in the shape of a water droplet, and the second conical surface 22 is designed with seven reinforced teeth 4 in the shape of an elliptical convexity. The height of the reinforced teeth 4 is 0.2-1.5mm. The arrangement of the reinforced teeth 4 on the two conical surfaces facilitates the discharge of coal seams or rocks, making it easier for them to enter the chip groove 5 on the pick body 1, improving cutting efficiency and reducing machine power loss. The reinforced teeth 4 are molded in one piece using the same material as the alloy head 2. The design of the reinforced teeth 4 enhances the wear resistance and rock-cutting efficiency of the alloy head 2.

[0082] The connection between the alloy head 2 and the pick body 1 adopts an interference fit hot pressing method; the specific connection method is to heat the pick body 1 to 250°C to temporarily expand the diameter of the installation groove 11 by about 0.05mm, and at the same time cool the alloy head 2 to -30°C to temporarily shrink its diameter by about 0.03mm; then quickly insert the alloy head 2 into the installation groove 11 of the pick body 1, apply 20 tons of pressure for 30 seconds, and after the temperature returns to normal, the alloy head 2 and the pick body 1 form a firm interference fit connection; this connection method avoids the heat-affected zone and material performance degradation problems that may be caused by traditional welding, and improves the connection strength and service life; by reducing the amount of precious metals used in the brazing process, the manufacturing cost of the tool is effectively reduced, and the problem of high cost of existing tools is solved.

[0083] After practical application testing at a coal mine, the six-edge pick-shaped coal cutter of this embodiment improved cutting efficiency by approximately 20% and reduced vibration and noise by approximately 15% compared to the four-edge structure of Example 2. Especially in coal cutting operations in hard coal seams, the six-edge structure demonstrated excellent stability and cutting performance, extending service life by approximately 60% compared to traditional cutters.

[0084] It should be noted that the three types of reinforcing teeth 4 (elliptical protrusions, water drop protrusions and spherical crown protrusions) disclosed in the present invention can be designed in combination according to the geological rock conditions. At the same time, the number of chip grooves 5 is also designed according to the geological rock conditions and mining depth and other working conditions. The combination of reinforcing teeth 4 and chip grooves 5 is designed according to the processing conditions, and many different combinations can be evolved, which are not limited to the combination forms shown in the accompanying drawings. That is to say, Example 1, Example 2, and Example 3 are all pick-type coal cutting tooth tools used in coal mining and excavation. Of course, they are not limited to this form. The number and layout of chip grooves 5, alloy heads 2, and reinforcing teeth 4 can be determined according to actual needs.

[0085] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0086] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A pick-type coal cutting tool for coal mining and excavation, comprising a cutting tool body (1) and an alloy head (2) fixed to the front end of the cutting tool body (1), wherein the side wall of the cutting tool body (1) has an alloy bean (3), characterized in that: The outer surface of the alloy head (2) is formed with an integral transition of a first conical surface (21) and a second conical surface (22), the second conical surface (22) is butted against the front end of the pick body (1), and the outer diameter of the second conical surface (22) gradually decreases in the extension direction of the first conical surface (21); the outer side walls of the first conical surface (21) and the second conical surface (22) are both provided with a plurality of evenly distributed reinforcing teeth (4), and the reinforcing teeth (4) are convex curved bodies with continuously changing surface curvature.

2. A pick-shaped coal cutting tool for coal mining and excavation according to claim 1, characterized in that: The taper of the second tapered surface (22) is greater than the taper of the first tapered surface (21); the second tapered surface (22) is a frustum structure, and the first tapered surface (21) is a cone structure.

3. The pick-shaped coal cutting tool for coal mining and excavation according to claim 1, characterized in that: The reinforcing teeth (4) are spherical crown protrusions, elliptical protrusions, or water drop protrusions, and the reinforcing teeth (4) on the first conical surface (21) and the second conical surface (22) are one of the spherical crown protrusions, the elliptical protrusions, or the water drop protrusions, or a combination of at least two different forms.

4. The pick-shaped coal cutting tool for coal mining and excavation according to claim 1, characterized in that: 4-8 reinforcing teeth (4) are fixed on both the first conical surface (21) and the second conical surface (22).

5. The pick-shaped coal cutting tool for coal mining and excavation according to claim 1, characterized in that: The outer side wall of the pick body (1) is provided with at least two chip removal grooves (5) arranged at intervals, and the alloy bean (3) is located between two adjacent chip removal grooves (5).

6. A pick-shaped coal cutting tool for coal mining and excavation according to claim 5, characterized in that: The number of the chip removal grooves (5) is 2-8.

7. The pick-shaped coal cutting tool for coal mining and excavation according to claim 5, characterized in that: The chip removal groove (5) is a spiral chip removal groove, and its cross section is a variable cross-section structure.

8. The pick-shaped coal cutting tool for coal mining and excavation according to claim 7, characterized in that: The chip removal groove (5) extends from the front edge of the pick body (1) toward the surface of the pick body (1).

9. A pick-shaped coal cutting tool for coal mining and excavation according to claim 8, characterized in that: The number of the alloy beans (3) is 10-18, and they are evenly distributed between two adjacent chip removal grooves (5).

10. The pick-shaped coal cutting tool for coal mining and excavation according to claim 1, characterized in that: The alloy bean (3) is a spherical crown.

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