CN103522014A - Laser combination welding thick-wall diamond bit manufacturing method - Google Patents

Abstract

The invention discloses a laser combination welding thick-wall diamond bit manufacturing method. By means of the technological process, a diamond bit embryo tooth of a multi-layer structure manufactured through a cold-pressing method is adopted, a diamond bit tooth shaped and manufactured through a hot-pressing sintering method is adopted, and a laser welding method is used for welding a plurality of diamond bit teeth coaxially on one end of a thick-wall steel pipe, wherein the circumference of each diamond bit tooth is equally divided and the circumferences of the diamond bit teeth are evenly distributed; after the welding process is conducted, the tempering process is conducted on the diamond bit teeth, a CO2 filler rod protecting welding or high-frequency brazing welding method is used for enhancing the welding strength between the diamond bit teeth and the thick-wall steel pipe, after the welding process is conducted, the tempering process is conducted on the diamond bit teeth and the thick-wall steel pipe, machining in relative size is conducted on the thick-wall steel pipe, and a finished bit is manufactured. Compared with existing sintering methods such as the medium frequency hot pressing sintering method, a resistance hot-pressing sintering method and a no-pressure dipping method, the cost of sintering molds for the laser combination welding thick-wall diamond bit manufacturing method can be reduced by 60 %, energy consumption can be reduced by 58 %, and overall efficiency can be improved by 50 %. Compared with an existing electrochemical plating method, the laser combination welding thick-wall diamond bit manufacturing method removes environmental-protection and recycling cost or heavy metal ions, or does not have environment pollution problems.

Description

Laser combined welding thick-walled diamond drill bit manufacturing method

(1) Technical field:

The invention relates to a method for manufacturing diamond drill bits for various types of geological exploration and engineering exploration, in particular to a method for manufacturing a laser combined welding thick-walled diamond drill bit.

(2) Background technology:

The thick-walled diamond drill bit is a kind of diamond tool. Its main feature is that one end of the thick-walled steel pipe is connected with diamond drill teeth, and the other end is processed with threads to connect with the core tube. Under the action, the rock is carved to realize drilling.

The existing manufacturing methods of diamond drill bits are mainly medium frequency hot pressing sintering method, resistance hot pressing sintering method, pressureless impregnation method and electroplating method.

The process flow of the intermediate frequency hot pressing sintering method is: drill bit design, calculation of the amount of powder and diamond—weighing and mixing of powder and diamond—preparing the core, bottom ring and nozzle block of the whole graphite mold—weighing The amount of mixed diamond powder is assembled into the overall graphite mold - thick-walled steel pipe processing and powder contact surface treatment - intermediate frequency hot pressing sintering - 12 hours in the incubator to cool slowly - exit the graphite outer mold, core, Nozzle block - finished product processing of thick-walled diamond drill bit.

It can be seen that the cost of the graphite mold of the sintering method is high, and the cost of electric energy consumption is also high.

The problem with the electroplating method is that the cost of environmental protection recycling of heavy metal ions is too high.

(3) Contents of the invention:

Aiming at the deficiencies of the existing manufacturing technology, the present invention proposes a manufacturing method of laser combined welding thick-walled diamond drill bits to solve the problems of high mold cost, high energy consumption, and low work efficiency of the sintering method of thick-walled geological drill bits, and the electroplating method The cost of environmental protection recycling of heavy metal ions is too high and the problem of environmental pollution.

The laser combined welding thick-walled diamond drill bit manufacturing method that can solve the above problems adopts the following process:

1. Using cold pressing method to manufacture multi-layered diamond drill teeth.

2. The shaped diamond bit teeth are manufactured by hot pressing sintering method.

3. Laser welding is used to coaxially weld several diamond bit teeth evenly distributed on the circumference to one end of the thick-walled steel pipe.

4. Tempering treatment after welding.

5. Use _CO2 filler wire protection welding or high-frequency brazing method to strengthen the welding strength between diamond bit teeth and thick-walled steel pipe.

6. Tempering treatment after welding.

7. Machining thick-walled steel pipes of relevant dimensions to produce finished drill bits.

In the series of thick-walled diamond drill bits, the inner and outer diameters of the series of thick-walled steel pipes are between 36mm and 400mm, and the thickness of the same thick-walled steel pipe is between 8mm and 25mm.

Correspondingly, the inner and outer radii of the series diamond bit teeth are between 18mm and 200mm, the inner and outer chord lengths are between 10mm and 40mm, and the height is between 8mm and 30mm. The difference between the inner and outer radii of the same diamond bit teeth is between 8mm and 25mm. The length difference between the inner and outer chords is between 3mm and 15mm.

The diamond bit tooth adopts a three-layer material structure along the radial direction, the diamond content of the middle layer material of the drill bit > the diamond content of the outer layer material of the drill bit > the diamond content of the inner layer material of the drill tooth.

The process parameters of the laser welding: penetration depth ≦ 7mm, welding power selection between 1KW ~ 2.3KW, incident angle < 5°, spot diameter between ￠0.15mm ~ ￠0.25mm, laser focal length between 170mm ~ 173mm Between, the spot offset of the drill bit and the steel body is between 5.5:4.5~6.5:3.5; the rotary speed of the thick-walled steel pipe during welding is between 0.6 m/min and 2 m/min.

The process parameters of the CO ₂ filled wire shielded welding: the diameter of the welding wire is between ￠0.8mm～￠1.2mm, the welding current is selected between 50A～280A, and the rotational speed of the thick-walled steel pipe during welding is 6 m/min～ 9 m/min.

The process parameters of the high-frequency brazing: the thickness of the silver solder sheet is between 0.2mm and 0.6mm, the welding temperature is between 650°C and 750°C, the heating power of a single diamond bit tooth is selected between 5KW and 10KW, and the heat preservation The time is between 5 seconds and 10 seconds.

Advantages of the present invention:

1. Compared with the sintering methods such as the existing medium-frequency hot-pressing sintering method, resistance hot-pressing sintering method, and pressureless impregnation method, the manufacturing method of the laser combination welding thick-walled diamond bit of the present invention can reduce the cost of the sintering mold by 60%, and the energy consumption can be reduced. Reduced by 58%, the overall efficiency can still be increased by 50%; compared with the existing electroplating method, the environmental protection recycling cost of heavy metal ions can be exempted, or there is no environmental pollution problem.

2. The present invention provides an environmentally friendly, high-efficiency, energy-saving, and low-cost manufacturing method for diamond drill bits used in geological exploration and engineering exploration.

(4) Description of the drawings:

Fig. 1 (a) is a structural schematic diagram of a thick-walled diamond drill bit manufactured by the manufacturing method of the present invention.

Figure 1(b) A-A sectional view in Figure 1(a).

Fig. 2 is a schematic diagram of the cold pressing of diamond drill teeth in the manufacturing process flow of the present invention.

Fig. 3 is a schematic diagram of hot-pressing sintering of diamond bit teeth in the manufacturing process flow of the present invention.

Fig. 4 is a schematic structural view of the thick-walled steel pipe in Fig. 1 .

Fig. 5(a) is a structural schematic diagram of a fixing fixture for laser welding in the manufacturing process of the present invention.

Fig. 5(b) is a schematic diagram of the structure of the drilling tooth equalization positioning mold in Fig. 5(a).

Fig. 6 is a schematic structural diagram of a fixing fixture for CO ₂ wire shielded welding in the manufacturing process of the present invention.

Drawing number identification: 1. Diamond drill teeth; 2. Thick-walled steel pipe; 3. Side form; 4. Backing plate; 5. Inner diameter pressure head; 6. Inner layer material of drill teeth; Tooth outer layer material; 9, outer diameter pressure head; 10, concave partition; 11, inclined partition; 12, middle partition; 13, sintered pressure plate; 14, strong magnet; 15, welding pressure plate; Sub-positioning die; 17. Positioning die for the outgoing edge of the drill bit; 18. Three-jaw chuck; 19. Drilling tooth welding fixed die; 20. Ejector.

(5) Specific implementation methods:

The technical solution of the present invention will be further described below in conjunction with the accompanying drawings.

The technological process of the laser combined welding thick-walled diamond drill bit manufacturing method of the present invention is: adopt the cold pressing method to manufacture the diamond drill bit embryo teeth of multilayer Weighing and mixing) - using hot pressing sintering method to manufacture shaped diamond bit teeth 1 - adopting laser welding method to coaxially weld a number of diamond bit teeth 1 equally distributed on the circumference to one end of thick-walled steel pipe 2 - welding Post-tempering treatment—adopt _CO2 filled wire shielded welding or high-frequency brazing method to strengthen the welding strength of diamond bit teeth 1 and thick-walled steel pipe 2—post-weld tempering treatment—machinery of relevant dimensions for thick-walled steel pipes Processing to produce finished drill bits.

The finished diamond drill bit after processing is shown in Figure 1.

Detailed explanation of each process flow:

1. Production of cold-pressed diamond drill teeth.

Manufacture with the drill bit tooth cold pressing mold (tool steel) shown in Fig. 2: surround mold cavity with left and right side mold 3 and front and rear partition, pad side mold 3 and partition with backing plate 4, let the bottom The inner diameter indenter 5 is exposed; pour the weighed drill tooth inner layer material 6 into the mold cavity at the inner diameter indenter 5 and level it out, then pour the weighed drill bit tooth middle layer material 7 and level it out, and finally pour it into Weigh the drill tooth outer layer material 8 and spread it flat, the diamond amount of the drill bit middle layer material 7 > the diamond amount of the drill bit outer layer material 8 > the diamond amount of the drill bit inner layer material 6, and the top outer diameter indenter 9 Put it into the mold cavity corresponding to the outer layer material 8 of the drill bit; tighten the side mold 3 and the partition with the screw, take the mold to the press to flatten the inner diameter indenter 5 and the outer diameter indenter 9 and keep the pressure for 5 seconds, take Go out of the mold, unscrew the screw rod, loosen the side mold 3 and the dividing plate, and take out the cold-pressed single diamond bit embryo tooth.

Repeat the above process until the required number of diamond drill teeth are cold pressed.

2. Fabrication of sintered diamond bit teeth 1.

Manufactured with the drill tooth hot-pressing sintering mold (separated high-strength graphite) shown in Figure 3: the mold cavity is surrounded by a concave partition 10, two inclined partitions 11 and a middle partition 12 (a total of 8 mold cavities,) , use pads to pad up the concave partition 10, the inclined partition 11, and the middle partition 12, so that the lower indenter is exposed, and the diamond drill teeth are placed in the 8 cavities in turn, and then the middle indenter is placed in turn, Put the diamond drill teeth in turn again, and finally put in the upper pressure head in turn, and finally tighten the screw to tighten the sintering platen 13 to lock the mold cavity, take it into the vacuum resistance furnace, heat it up to 870°C for 5 minutes, and hold the pressure at 220kg /CM ² , and vacuum degree -0.08MPa to sinter the finished product of diamond bit teeth 1 .

3. Production of thick-walled steel pipe 2.

Process the thick-walled steel pipe 2 (preferably 45# steel) shown in Figure 4 by conventional machining methods.

4. Laser welding the diamond bit teeth 1 on the thick-walled steel pipe 2. Use the laser welding fixtures (all 45# steel) shown in Figure 5(a) and Figure 5(b) to fix the welded drill bit teeth. First place the strong magnet 14 horizontally, place the welding press plate 15 on the strong magnet 14, place the drilling tooth equalization positioning mold 16 on the welding pressing plate 15, and place the drilling tooth equalization positioning mold 16 in the cavity (the circumference is evenly distributed 8 equal divisions) Put in the finished product of diamond bit teeth 1 (with the processed welding surface facing upwards), put the inner hole end of the outer edge positioning mold 17 of the drill bit teeth downwards to cover the outer circle composed of 8 diamond bit teeth 1, and place the thick-walled steel pipe 2 Put the welding surface of the drill bit face down into the positioning mold 17 for the outgoing edge of the drill bit, and finally take the fixed set of fixtures horizontally to the three-jaw chuck 18 of the laser welding machine for tension, and then place the positioning mold 17 for the outgoing edge of the drill bit Slide to expose the joint surface of the thick-walled steel pipe 2 and the diamond bit tooth 1, and weld the diamond bit 1 and the thick-walled steel pipe 2 together according to the following welding process parameters: the welding power is 1.5KW, the incident angle is 3.5°, and the spot The diameter is ￠0.2mm, the laser focal length is 172mm, the drill bit tooth and steel body in the spot offset is 6:4, and the thick-walled steel pipe 2 rotates at a linear speed of 0.8 m/min.

The welded semi-finished drill bit is kept in an oven at 240°C for 3 hours and then cooled with the furnace.

5. CO ₂ filler wire shielded welding enhances welding strength

Fix the semi-finished thick-walled steel pipe 2 of the drill bit on the three-jaw chuck 18 of the lathe with the fixed fixture (45# steel) for _CO2 filler wire protection welding shown in Figure 6, and set the drill tooth welding fixed mold 19 on the welded On the inner and outer diameters of the diamond drill bit teeth 1, use the thimble 20 of the lathe to withstand the drill tooth welding fixed mold 19; align the welding head of the _CO2 wire-filled shielded welding with the welding between the thick-walled steel pipe 2 and the diamond drill bit teeth 1 seam (has been processed in the production of thick-walled steel pipe 2), according to the following parameters of CO ₂ filler wire protection welding, the diamond bit teeth 1 and thick-walled steel pipe 2 are welded together: the diameter of the welding wire is selected as ￠0.8mm, and the welding current is selected as 65A. The linear speed of rotation of the thick-walled steel pipe 2 during welding is 8 m/min.

Put the semi-finished drill bit that has been welded into an oven to keep warm at 270°C, and then cool down with the furnace after keeping the heat for 3 hours.

6. Finished product processing.

Process the semi-finished product of the drill bit that has been cooled to produce the finished product of the thick-walled drill bit shown in Figure 1 (a) and Figure 1 (b) according to the conventional mechanical processing method (including the thread processing that the other end of the thick-walled steel pipe 2 is connected to the core pipe), and manufacture A full thick wall diamond drill bit.

The size of the diamond drill bit in the present invention can be designed in different sizes according to the different requirements of the processing object or the different working conditions of the tool.

In the series of thick-walled diamond drill bits of the present invention:

The inner and outer diameters of the series of thick-walled steel pipes 2 are 36 mm to 400 mm, and the thick wall of the same thick-walled steel pipe 2 is 8 mm to 25 mm.

Correspondingly, the inner and outer radii of a series of diamond bit teeth 1 are 18 mm to 200 mm, the inner and outer chord lengths are 10 mm to 40 mm, and the height is 8 mm to 30 mm. 3mm to 15mm.

Claims (7)

1. laser in combination welds heavy wall diamond drill machine method for making head, it is characterized in that the technological process of taking is:

1., adopt cold-press method to manufacture the diamond bit embryo tooth of sandwich construction;

2., adopt hot pressing sintering method to manufacture the diamond bit tooth (1) of moulding;

3., adopt method for laser welding uniform diamond bit tooth (1) coaxial welding of some circumference equal dividings the one end in thick walled steel tube (2);

4., postwelding temper;

5., adopt CO ₂protection weldering or the high frequency brazing method of filling silk strengthened the weld strength of diamond bit tooth (1) and thick walled steel tube (2);

6., postwelding temper;

7., thick walled steel tube (2) is carried out the machining of relative dimensions and produces drill bit finished product.

2. laser in combination welding heavy wall diamond drill machine method for making head according to claim 1, is characterized in that: the inner and outer diameter of serial thick walled steel tube (2) is 36mm～400mm, and the heavy wall of same thick walled steel tube (2) is 8mm～25mm.

3. laser in combination according to claim 2 welds heavy wall diamond drill machine method for making head, it is characterized in that: the interior outer radius of serial diamond bit tooth (1) be 18mm～200mm, inside and outside chord length be 10mm～40mm, highly for 8mm～30mm, the inside and outside semidiameter of same diamond bit tooth (1) be 8mm～25mm, inside and outside chord length poor be 3mm～15mm.

4. according to the laser in combination welding heavy wall diamond drill machine method for making head described in any one in claim 1～3, it is characterized in that: described diamond bit tooth (1) for radially interior, in, outer three layered material structures, the diamond consumption of layered material (6) in the diamond consumption > bit teeth of the outer layered material (8) of the diamond consumption > bit teeth of bit teeth middle material (7).

5. according to the laser in combination welding heavy wall diamond drill machine method for making head described in any one in claim 1～3, it is characterized in that: the saturating Shen Du≤7mm of weldering of described laser weld, bonding power is 1KW～2.3KW, 5 ° of incidence angle <, spot diameter is ￠ 0.15mm～￠ 0.25mm, laser focal is 170mm～173mm, and in facula deviation amount, bit teeth and steel body are 5.5:4.5～6.5:3.5; Thick walled steel tube during welding (2) turning spur speed is 0.6 m/min～2 ms/min.

6. according to the laser in combination welding heavy wall diamond drill machine method for making head described in any one in claim 1～3, it is characterized in that: described CO ₂the gage of wire that the protection that fills silk is welded is ￠ 0.8mm～￠ 1.2mm, and welding current is 50A～280A, and the turning spur speed of thick walled steel tube during welding (2) is 6 ms/min～9 ms/min per minute.

7. according to the laser in combination welding heavy wall diamond drill machine method for making head described in any one in claim 1～3, it is characterized in that: the silver soldering sheet thickness of described high frequency brazing is 0.2mm～0.6mm, welding temperature is 650 ℃～750 ℃, the power of single diamond bit tooth (1) heating is 5KW～10KW, and temperature retention time is 5 seconds～10 seconds.

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