Taper drill rod and manufacturing method thereof

Abstract

The invention relates to the technical field of drill rods, in particular to a taper drill rod and a manufacturing method thereof.The taper drill rod comprises a taper drill rod body and a collar disc, the taper drill rod body comprises a rod body, a tail handle and a drill tip, an inner hole extending in the axial direction of the rod body is formed in the taper drill rod body, the taper drill rod body further comprises a hollow billet installed in the inner hole and extending in the axial direction, and the hollow billet is made of corrosion-resistant materials; the hollow billet is provided with a flaring for connecting a fluid supply device at one end of the drill tip; the tubular billet can improve the corrosion resistance of the inner hole of the conical drill rod and prevent the inner hole from being blocked and the strength from being reduced due to corrosion of the conical drill rod; in the rolling process of the conical drill rod, the hollow billet and the core rod are inserted into the inner hole of the conical drill rod, so that the inner hole of the conical drill rod can be supported in the rolling process, and the situation that the strength of the conical drill rod is reduced due to deformation of the inner hole is avoided; meanwhile, the lubricant is smeared on the surface of the core rod, so that the sliding friction coefficient between the conical drill rod and the hollow billet is reduced, and the friction resistance of the core rod when the core rod is pulled out is further reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of drill rods, and in particular to a tapered drill rod and a manufacturing method thereof. Background Art

[0002] Rock drills are common rock mining equipment used in mining projects, crushing rock through the principle of impact crushing. The drill rod is the core component of the rock drill, transmitting the impact force generated by the rock drill to the drill bit while also bearing the rotational torque to crush the rock. During operation, the drill rod must withstand high-frequency impact stresses and the combined stresses of tension, compression, and bending, requiring high strength and fatigue resistance. Furthermore, the drill rod has a hollow structure inside for conveying high-pressure fluids, enabling chip removal and cooling during the crushing process.

[0003] Existing drill rods typically first create an internal hollow structure by drilling, and then roll the rod's external shape. This rolling process often causes deformation of the rod's internal hollow structure, requiring further correction of the hollow structure at a later stage. To address this issue, existing technologies use a mandrel inserted into the hollow structure to provide internal support during the rod rolling process.

[0004] For example, Chinese patent document CN114558891B discloses a method for hot rolling hollow steel for drill rods, hollow steel, and a hot rolling mill. The method comprises: heating a billet, wherein the billet is bainitic steel; perforating the heated billet; inserting a mandrel into the perforation; performing a diameter reduction rolling on the billet with the mandrel inserted, and withdrawing the mandrel from the perforation during the diameter reduction rolling process; performing a sizing rolling on the billet with the mandrel withdrawn; and cooling the billet after sizing rolling. The mandrel provides good support for the bainitic steel, effectively reducing deformation of the bainitic steel and improving rolling accuracy. During the diameter reduction rolling of the bainitic steel, the mandrel is withdrawn from the perforation, saving process time and making it easier to withdraw the mandrel from the perforation, effectively reducing the risk of mandrel breakage during withdrawal and improving the reliability of the diameter reduction rolling process.

[0005] However, the above method still has certain defects: the pressure between the drill rod and the core rod increases during the rolling process, resulting in an increase in the sliding friction between the core rod and the drill rod, making the core rod still more difficult and at risk of breakage during the subsequent extraction process. The breakage of the core rod will greatly affect the production efficiency of the drill rod; in addition, the inner hole structure of the drill rod is generally used for passing water or other liquids, and the working environment is harsh. During long-term use, it is easy to cause rust in the hole, which in turn leads to blockage of the inner hole or affects the use strength of the drill rod, reducing the service life of the drill rod.

[0006] Therefore, a tapered drill rod is needed that can reduce the difficulty of extracting the core rod and prevent the inner hole structure of the tapered drill rod from rusting. Summary of the Invention

[0007] The present invention provides a tapered drill rod and a manufacturing method thereof, which can reduce the difficulty of extracting a core rod and prevent the inner hole structure of the tapered drill rod from rusting.

[0008] In order to solve the above problems, the present invention provides a tapered drill rod adopting the following technical solutions: A tapered drill rod comprises a tapered drill rod and a collar. The tapered drill rod comprises a rod body, a tail handle and a drill tip. The tapered drill rod has an inner hole extending axially along the rod body. The tapered drill rod also comprises an axially extending capillary installed in the inner hole. The length of the capillary is equal to the length of the inner hole. The capillary has a flared opening at one end of the drill tip for connecting to a fluid supply device. The capillary is made of corrosion-resistant material.

[0009] The tapered drill rod of the present invention is provided with a capillary tube made of corrosion-resistant material in the inner hole, so that the inner hole of the tapered drill rod can be prevented from rusting during use, thereby avoiding blockage of the inner hole of the drill rod and reduction in strength due to rust of the drill rod, thereby extending the service life of the drill rod; in addition, the expansion hole setting facilitates the connection between the fluid supply device and the drill rod, and also improves the applicability of the drill rod.

[0010] Furthermore, the capillary tube is made of 40MnMoV, and the wall thickness of the capillary tube is 1-3 mm.

[0011] Furthermore, the cross-section of the rod body is polygonal, the collar is a circular column or a polygonal column, and has a sleeve hole inside that matches the outer circumference of the rod body, and the collar is sleeved on the tapered drill rod through the sleeve hole.

[0012] Furthermore, the collar includes a rubber layer and a metal layer. The rubber layer is sleeved on the outer circumference of the tapered drill rod and fixed to the tapered drill rod. The metal layer is sleeved on the outer side of the rubber layer and bonded to the rubber layer.

[0013] Its beneficial effects are: by arranging a split assembled collar on the tapered drill rod, the problems of inner hole defects and reduced strength caused by the traditional one-piece forged collar are avoided, the service life of the tapered drill rod is extended, and the production efficiency of the drill rod is improved; in addition, by arranging the collar as a structure in which a rubber layer and a metal layer are sheathed, the elasticity of the rubber itself is utilized to effectively absorb and disperse the impact force of the drill rod on the rock drilling equipment, thereby extending the service life of the drill rod while reducing the impact on the rock drilling equipment.

[0014] The beneficial effects of the tapered drill rod provided by the present invention are: 1. The tapered drill rod of the present invention is provided with a capillary tube made of corrosion-resistant material in the inner hole, so that the inner hole of the tapered drill rod can be prevented from rusting during use, thereby avoiding blockage of the inner hole of the drill rod and reduction in strength due to rust of the drill rod, thereby extending the service life of the drill rod; in addition, the setting of the expanded hole facilitates the connection between the fluid supply device and the drill rod, and also improves the applicability of the drill rod.

[0015] 2. By arranging a split assembled collar on the tapered drill rod, the problems of inner hole defects and reduced strength caused by the traditional one-piece forged collar are avoided, the service life of the tapered drill rod is extended, and the production efficiency of the drill rod is improved. In addition, by setting the collar as a structure in which a rubber layer and a metal layer are sheathed, the elasticity of the rubber itself is utilized to effectively absorb and disperse the impact force of the drill rod on the rock drilling equipment, thereby extending the service life of the drill rod while reducing the impact on the rock drilling equipment.

[0016] In order to solve the above problems, the present invention provides a method for manufacturing a tapered drill rod by adopting the following technical solutions: A method for manufacturing a tapered drill rod, comprising the following steps: a. Cut the raw materials into blanks of a certain size, and then drill the blanks; b. Insert a capillary tube made of corrosion-resistant material into the drilled hole, insert a core rod used to support the capillary tube and the hole into the capillary tube, and apply lubricant to the surface of the core rod before inserting it into the capillary tube to reduce the sliding friction between the core rod and the capillary tube; c. Heating the raw material billet, and then rolling the raw material billet, the rough tube and the mandrel together, rolling the raw material billet, the rough tube and the mandrel into a certain size and shape, and then extracting the mandrel from the raw material billet, and then cutting again; d. Expand the capillary tube and the inner hole near the drill tip to form a flared opening, and then trim the dimensional accuracy of the outer surface of the raw material blank; e. Turning the drill tip to form a circumferentially extending tapered surface, and then normalizing, quenching and polishing the tapered drill rod; f. Place the collar on the tapered drill rod, and then apply radial pressure to the collar to press the collar onto the tapered drill rod.

[0017] A manufacturing method of a tapered drill rod of the present invention inserts a capillary tube and a core rod into the inner hole of the tapered drill rod, so that the inner hole of the tapered drill rod can be supported during the rolling process, and the deformation of the inner hole during the rolling process can be controlled within a certain range, thereby avoiding a decrease in the strength of the tapered drill rod due to deformation of the inner hole; in addition, by installing a capillary tube made of corrosion-resistant material, the inner hole of the tapered drill rod can be prevented from being corroded during long-term use, thereby improving the service life of the tapered drill rod; at the same time, by applying lubricant on the surface of the core rod, the sliding friction coefficient between the tapered drill rod and the capillary tube is reduced, thereby reducing the friction resistance of the core rod when it is pulled out, and improving the production stability of the tapered drill rod.

[0018] Furthermore, in step f, the collar plate includes a rubber layer and a metal layer sleeved on the outside of the rubber layer, and the metal layer is bonded to the rubber layer.

[0019] The beneficial effect is that the metal layer bonded to the rubber layer allows the collar to effectively absorb and disperse the impact force generated during the use of the tapered drill rod, reducing vibration and stress concentration in the drill rod, and lowering the risk of fracture and wear of the tapered drill rod. Furthermore, the metal layer reduces wear between the rubber layer and the rock drilling equipment, thereby extending the service life of the drill rod.

[0020] Furthermore, in step f, the rubber layer and the tapered drill rod are bonded together by glue while being pressed together, so as to enhance the friction between the collar and the tapered drill rod.

[0021] Furthermore, the material of the capillary tube is 40MnMoV. During the hot rolling process, the outer surface of the capillary tube is fused with the inner hole of the raw material billet, thereby enhancing the connection strength between the capillary tube and the raw material billet. The lubricant is lime.

[0022] Its beneficial effect is that the outer wall of the shell and the wall of the inner hole fuse at high temperature during the rolling process, thereby enhancing the bonding strength of the cross section and the structural integrity of the tapered drill rod, which is beneficial to extending the service life of the tapered drill rod.

[0023] Furthermore, the step f also includes testing the collar size, the taper of the tapered drill rod, and the tensile strength between the collar and the rod body to ensure the production quality of the tapered drill rod and the connection quality between the collar and the tapered drill rod.

[0024] Its beneficial effect is that by testing the collar disc size, the taper of the tapered drill rod, and the tensile strength between the collar disc and the rod body, defective products in the production process can be screened out, the production quality of the tapered drill rod and the connection quality between the collar disc and the tapered drill rod are improved, and the production quality of the tapered drill rod is guaranteed.

[0025] Furthermore, the material of the raw material blank is 55SiMnMo, and the material of the core rod is 80Mn14Ti.

[0026] The beneficial effects of the method for manufacturing a tapered drill rod provided by the present invention are: 1. A method for manufacturing a tapered drill rod of the present invention inserts a capillary tube and a core rod into the inner hole of the tapered drill rod, so that the inner hole of the tapered drill rod can be supported during the rolling process, and the deformation of the inner hole during the rolling process can be controlled within a certain range, thereby avoiding a decrease in the strength of the tapered drill rod due to deformation of the inner hole; in addition, by installing a capillary tube made of corrosion-resistant material, the inner hole of the tapered drill rod can be prevented from being corroded during long-term use, thereby improving the service life of the tapered drill rod; at the same time, by applying lubricant on the surface of the core rod, the sliding friction coefficient between the tapered drill rod and the capillary tube is reduced, thereby reducing the friction resistance of the core rod when it is pulled out, and improving the production stability of the tapered drill rod.

[0027] 2. The metal layer bonded to the rubber layer allows the collar to effectively absorb and disperse the impact force generated during the use of the tapered drill rod, reducing vibration and stress concentration in the drill rod, and lowering the risk of fracture and wear. Furthermore, the metal layer reduces wear between the rubber layer and the rock drilling equipment, thereby extending the service life of the drill rod.

[0028] 3. During the rolling process, the outer wall of the capillary tube and the wall of the inner hole fuse at high temperature, which enhances the bonding strength of the cross section and the structural integrity of the tapered drill rod, which is beneficial to extending the service life of the tapered drill rod.

[0029] 4. By testing the collar size, taper of the tapered drill rod, and the tensile strength between the collar and the rod body, defective products in the production process can be screened out, the production quality of the tapered drill rod and the connection quality between the collar and the tapered drill rod are improved, and the production quality of the tapered drill rod is guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic structural diagram of a tapered drill rod provided by the present invention; Figure 2 A cross-sectional view of a tapered drill rod provided by the present invention; Figure 3 for Figure 1 Schematic diagram of the structure of the middle collar plate; Figure 4 The present invention provides a schematic flow chart of a method for manufacturing a tapered drill rod.

[0031] Description of reference numerals: 1. Conical drill rod; 11. Rod body; 12. Drill tip; 13. Tail handle; 14. Capillary tube; 15. Inner hole; 16. Hole expansion; 2. Collar; 21. Rubber layer; 22. Metal layer. DETAILED DESCRIPTION

[0032] The principles and spirit of the present invention are explained in detail below with reference to several representative embodiments of the present invention.

[0033] Example 1 of a tapered drill rod provided by the present invention: like Figures 1 to 3 As shown, the tapered drill rod comprises a tapered drill rod 1 and a collar 2. The tapered drill rod 1 is a regular hexagonal columnar structure with a 22 mm diagonal width, used to connect the drill bit and the rock drill. The tapered drill rod 1 extends in the left-right direction. The collar 2 is mounted on the tapered drill rod 1 to transmit impact force and secure the drill rod.

[0034] First, the tapered drill rod 1 is introduced below. Figure 1 and Figure 2 As shown, the tapered drill rod 1 comprises a rod body 11, a drill tip 12, a shank 13, and a capillary tube 14. The drill tip 12 is located at the left end of the rod body 11. It has a tapered structure with a diameter that gradually decreases from right to left, and is used to securely connect with the tapered hole of the drill bit through friction generated by extrusion. The tapered structure has a taper angle of 11 degrees, and the end diameter of the drill tip 12 is 17.5 mm, with a dimensional accuracy of plus or minus 0.1 mm. The shank 13 is located at the right end of the rod body 11 and is designed to be inserted into the connecting sleeve of a rock drill to bear and transmit the impact force, torque, and propulsion force of the rock drill. The outer peripheral surface of the shank 13 is a regular hexagonal surface with a dimensional accuracy of plus or minus 0.2 mm to match the connecting sleeve of the rock drill and ensure the reliability of the connection between the shank 13 and the rock drill.

[0035] The inside of the tapered drill rod 1 has an inner hole 15 extending left and right. The inner hole 15 is a through hole for connecting the outer hole of the fluid supply device and the drill bit so that the high-pressure fluid input by the fluid supply device can be delivered to the drill bit. The fluid input by the fluid supply device is high-pressure water or high-pressure air to achieve cooling and chip removal of the drill bit. The capillary tube 14 is a circular pipe extending left and right. Its material is 40MnMoV. The capillary tube 14 is located in the inner hole 15. The length of the capillary tube 14 is consistent with the length of the inner hole 15. Its outer wall is fused with the wall of the inner hole 15 at high temperature during the rolling process to enhance the integrity of the structure of the tapered drill rod 1 and the connection strength of the interface. The capillary tube 14 has the characteristics of corrosion resistance. It can avoid the tapered drill rod from rusting in harsh environments, and then can prevent the traditional drill rod from being blocked by the inner hole 15 due to rust after long-term use, and simultaneously avoid the decline of the structural strength of the tapered drill rod 1 due to rust. The right end of the capillary tube 14 has a countersunk hole 16, which has a larger diameter than the hole at the left end. Countersunk hole 16 is used to connect to a fluid supply device, thereby improving the convenience of connecting the drill rod and the fluid supply device. The left and right ends of the capillary tube 14, the drill tip 12, and the end of the tail shank 13 are all chamfered to facilitate the installation of the tapered drill rod and reduce the probability of stress concentration during use.

[0036] The following introduces the lead plate 2, such as Figures 1 to 3 As shown, the collar 2 comprises a rubber layer 21 and a metal layer 22. The rubber layer 21 is a sleeve-shaped structure extending horizontally. The rubber layer 21 has a sleeve hole extending horizontally. The rubber layer 21 is sleeved onto the rod body 11 of the tapered drill rod 1 through the sleeve hole. The inner side of the rubber layer 21 is a regular hexagonal surface, and the outer side is a cylindrical surface. The outer side of the rubber layer 21 has a diameter of 40 mm, with a dimensional tolerance of plus or minus 0.2 mm. The metal layer 22 is a tubular structure extending horizontally. The metal layer 22 is made of 20 steel and has a wall thickness of 4 mm. The metal layer 22 is sleeved onto the outer side of the rubber layer 21 and is bonded to the rubber layer 21 with glue. Because the metal layer 22 has a higher hardness than the rubber layer 21, it can reduce wear of the rubber layer 21 during use, thereby extending the service life of the tapered drill rod.

[0037] Furthermore, the collar disc 2 is pressed onto the rod body 11 of the tapered drill rod 1 during production using a tube crimping machine. Therefore, the inner side of the collar disc 2 has a smaller width than the outer side of the rod body 11, thereby enhancing the connection stability between the collar disc 2 and the tapered drill rod 1. Glue is also present between the collar disc 2 and the rod body 11 to increase friction between the collar disc 2 and the drill rod, preventing the collar disc 2 from slipping during use.

[0038] Compared with the traditional forging collar 2, the composite structure of the metal layer 22 and the rubber layer 21 avoids the problems of inner hole 15 defects and reduced strength caused by the traditional one-piece forging collar 2, extends the service life of the tapered drill rod 1, can effectively absorb and disperse the impact force of the drill rod on the rock drilling equipment, reduce the impact on the rock drilling equipment, and also improve the production efficiency of the drill rod.

[0039] Example 2 of a tapered drill rod provided by the present invention: The main difference between it and Example 1 is: In Example 1, the cross-sectional shape of the tapered drill rod is a regular hexagon, and the corresponding sleeve hole of the rubber layer is also a regular hexagon.

[0040] In this embodiment, the cross-sectional shape of the tapered drill rod is a circle, a regular quadrilateral, a regular octagon, or a regular dodecagon, and the shape of the sleeve hole of the rubber layer corresponds to the cross-sectional shape of the tapered drill rod.

[0041] Example 3 of a tapered drill rod provided by the present invention: The main difference between it and Example 1 is: In Example 1, the collar includes a rubber layer and a metal layer bonded to the outer side of the rubber layer.

[0042] In this embodiment, the collar includes a rubber body and a metal ring installed in the rubber body, and the metal ring is used to enhance the rigidity of the rubber body.

[0043] Example 1 of a method for manufacturing a tapered drill rod provided by the present invention: like Figure 4 The specific steps are as follows: a. Use 55SiMnMo bainitic steel as the raw material for the tapered drill rod 1. Cut 150 cubic meters of raw material and divide it into multiple raw material billets of a certain size. Then, drill each raw material billet. The diameter of the drilled hole is 56.5 mm, and the dimensional accuracy is plus or minus 0.2 mm.

[0044] b. Insert a capillary tube 14 into the drilled hole. The capillary tube 14 is made of 40MnMoV, has an outer diameter of 56.5 mm, and an inner diameter of 48.5 mm. A cylindrical mandrel made of 80Mn14Ti with a diameter of 48.5 mm is inserted into the capillary tube 14 to support the capillary tube 14 and the inner hole 15. The mandrel is used to control the deformation of the drilled hole during the rolling process within a predetermined range, thereby preventing excessive deformation of the inner hole 15 during the rolling process, which would otherwise reduce the strength of the tapered drill rod 1. Before inserting the mandrel into the capillary tube 14, the surface of the mandrel is coated with lime to reduce the sliding friction coefficient between the tapered drill rod 1 and the capillary tube 14. This reduces the frictional resistance of the mandrel when it is withdrawn after rolling, reducing the probability of the mandrel breaking during withdrawal and improving the production efficiency of the tapered drill rod.

[0045] 40MnMoV has good corrosion resistance. By inserting a capillary tube 14 made of 40MnMoV into the inner hole, the inner hole wall of the tapered drill rod 1 is fused with the outer wall of the capillary tube 14 during the hot rolling process, thereby forming a corrosion-resistant protective layer on the inner hole wall, preventing the inner hole of the tapered drill rod from rusting during use, thereby extending the service life of the tapered drill rod and reducing the probability of the inner hole 15 being blocked due to rust, thereby improving the stability of the tapered drill rod.

[0046] c. The raw material billet is heated to 1100°C-1200°C and then rolled. During the rolling process, the diameters of the raw material billet, the capillary tube 14 and the mandrel are gradually reduced. During the high-temperature rolling process, the outer wall of the capillary tube 14 is fused with the inner hole wall, and the structural integrity of the capillary tube 14 and the tapered drill rod 1 is enhanced. The raw material billet is rolled into a regular hexagonal columnar structure with a flat width of 22 mm. The aperture of the capillary tube 14 is 6.4 mm, and then the mandrel is pulled out from the raw material billet.

[0047] d. Use a reaming device 16 to reame 16 the capillary tube 14 and the inner hole 15 at one end near the drill tip 12 to form a flared opening. The flared opening has a length of 70 mm and is used to connect the fluid supply equipment. Then, use a shaping device to trim the dimensional accuracy of the regular hexagonal outer surface of the raw material blank so that the dimensional accuracy of the outer surface of the raw material blank reaches plus or minus 0.2 mm to ensure the matching accuracy of the tail handle 13 and the connecting sleeve of the rock drill. Then, chamfer the two ends of the tapered drill rod 1 to reduce the probability of stress concentration during use of the tapered drill rod 1.

[0048] e. The drill tip 12 is turned to form a tapered surface with a diameter gradually decreasing from the middle to the end. The taper of the tapered surface is 11 degrees, and the diameter of the end of the drill tip 12 is 17.5 mm. The tapered drill rod 1 is then normalized, quenched, and surface polished to enhance the structural strength of the tapered drill rod 1.

[0049] f. The collar 2 includes a rubber layer 21 and a metal layer 22. The outer diameter of the rubber layer 21 is 34 mm, and the metal layer 22 is made of 20 steel with a wall thickness of 4 mm. The rubber layer 21 is first sleeved on the determined position of the tapered drill rod 1 and bonded with glue to enhance the friction between the rubber layer 21 and the tapered drill rod 1. Then, the metal layer 22 is sleeved and bonded to the rubber layer 21. Then, a tube locking machine is used to apply radial pressure to the metal layer 22 and the rubber layer 21 to press the rubber layer 21 onto the tapered drill rod 1. After the pressing is completed, the size of the collar 2, the taper of the drill tip 12 of the tapered drill rod 1, and the tensile strength between the collar 2 and the rod body 11 are tested respectively to ensure the production quality of the tapered drill rod 1 and the connection quality of the collar 2 and the tapered drill rod 1.

[0050] The structure of the metal layer 22 bonded to the rubber layer 21 effectively absorbs and disperses the impact force generated during the use of the tapered drill rod 1, reducing vibration and stress concentration in the drill rod, and lowering the risk of fracture and wear of the tapered drill rod 1. Furthermore, the provision of the metal layer 22 also reduces wear between the rubber layer 21 and the rock drilling equipment, thereby extending the service life of the drill rod. Furthermore, by testing the size of the collar 2, the taper of the tapered drill rod 1, and the tensile strength between the collar 2 and the rod body 11, defective products can be screened out during the production process, ensuring the production quality of the tapered drill rod.

[0051] Example 2 of a method for manufacturing a tapered drill rod provided by the present invention: The main difference between it and Example 1 is: In Example 1, lime was used as a lubricant between the capillary tube and the core rod.

[0052] In this embodiment, graphite powder is used as a lubricant between the capillary and the core rod.

[0053] According to the above description of this specification, those skilled in the art may also understand that the terms used below, such as "up", "down", "front", "back", "left", "right", "width", "horizontal", "top", "bottom", "inside", "outside" and other terms indicating orientation or positional relationships are based on the orientation or positional relationships shown in the drawings of this specification. They are only for the purpose of facilitating the explanation of the scheme of the present invention and simplifying the description, rather than explicitly or implicitly indicating that the devices or elements involved must have the specific orientation, be constructed and operated in a specific orientation. Therefore, the above-mentioned orientation or positional relationship terms cannot be understood or interpreted as limitations on the scheme of the present invention.

[0054] In addition, in the description of this specification, “a plurality of” means at least two, for example, two, three or more, etc., unless otherwise clearly and specifically defined.

Claims

1. A tapered drill rod, comprising a tapered drill rod and a collar, wherein the tapered drill rod comprises a rod body, a tail shank and a drill tip, and the tapered drill rod has an inner hole extending along the axial direction of the rod body, characterized in that: The tapered drill rod also includes a capillary tube installed in the inner hole and extending axially. The length of the capillary tube is equal to the length of the inner hole. The capillary tube has a flared opening at one end of the drill tip for connecting to a fluid supply device. The capillary tube is made of corrosion-resistant material.

2. A tapered drill rod according to claim 1, characterized in that: The capillary tube is made of 40MnMoV, and the wall thickness of the capillary tube is 1-3 mm.

3. A tapered drill rod according to claim 1, characterized in that: The cross-section of the rod body is polygonal, and the collar is a circular column or a polygonal column with a sleeve hole inside that matches the outer peripheral surface of the rod. The collar is sleeved on the tapered drill rod through the sleeve hole.

4. A tapered drill rod according to claim 3, characterized in that: The collar comprises a rubber layer and a metal layer. The rubber layer is sleeved on the outer peripheral surface of the tapered drill rod and fixed to the tapered drill rod. The metal layer is sleeved on the outer side of the rubber layer and bonded to the rubber layer.

5. A method for manufacturing a tapered drill rod, characterized in that: The specific steps are as follows: a. Cut the raw materials into blanks of a certain size, and then drill the blanks; b. Insert a capillary tube made of corrosion-resistant material into the drilled hole, and insert a core rod used to support the capillary tube and the inner hole into the capillary tube. Apply lubricant to the surface of the core rod before inserting it into the capillary tube to reduce the sliding friction between the core rod and the capillary tube; c. Heating the raw material billet, and then rolling the raw material billet, the rough tube and the mandrel together, rolling the raw material billet, the rough tube and the mandrel into a certain size and shape, and then extracting the mandrel from the raw material billet, and then cutting again; d. Expand the capillary tube and the inner hole near the drill tip to form a flared opening, and then trim the dimensional accuracy of the outer surface of the raw material blank; e. Turning the drill tip to form a circumferentially extending tapered surface, and then normalizing, quenching and polishing the tapered drill rod; f. Place the collar on the tapered drill rod, and then apply radial pressure to the collar to press the collar onto the tapered drill rod.

6. The method for manufacturing a tapered drill rod according to claim 5, characterized in that: In the step f, the collar includes a rubber layer and a metal layer sleeved on the outside of the rubber layer, and the metal layer is bonded to the rubber layer.

7. The method for manufacturing a tapered drill rod according to claim 6, characterized in that: In the step f, the rubber layer and the tapered drill rod are bonded together by glue while being pressed together, so as to enhance the friction between the collar and the tapered drill rod.

8. The method for manufacturing a tapered drill rod according to claim 5, characterized in that: The material of the capillary tube is 40MnMoV. During the hot rolling process, the outer surface of the capillary tube is fused with the inner hole of the raw material billet, thereby enhancing the connection strength between the capillary tube and the raw material billet. The lubricant is lime.

9. The method for manufacturing a tapered drill rod according to claim 5, characterized in that: The step f also includes testing the collar size, the taper of the tapered drill rod, and the tensile strength between the collar and the rod body to ensure the production quality of the tapered drill rod and the connection quality between the collar and the tapered drill rod.

10. The method for manufacturing a tapered drill rod according to claim 5, characterized in that: The material of the raw material blank is 55SiMnMo, and the material of the core rod is 80Mn14Ti.

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