Contact tube of double-protection welding gun

Abstract

The invention discloses a contact tube of a double-protection welding gun. The contact tube is prepared by the following steps: step 1, selecting raw materials; step 2, raw material pretreatment; step 3, burdening and mixing; step 4, forming; step 5, roasting; step 6, graphitizing; step 7, manufacturing a blank; step 8, finish machining; the method has the advantages that graphite is adopted as a main material to manufacture the contact tube of the two-protection welding gun, and the graphite contact tube cannot be melted by high-temperature electric arcs generated by a welding wire and the inner wall of the contact tube in the welding production process due to the fact that the melting point of the graphite is about 3800 DEG C, so that adhesion of the welding wire and the contact tube is thoroughly avoided; due to the high melting point of graphite and the characteristic of surface pulverization at about 1000 DEG C, adhesion between the graphite and high-temperature metal splashes is reduced, a small amount of slag is easy to clean, the frequency and time for replacing and cleaning the contact tube in the welding production process of carbon dioxide arc welding are reduced, and the graphite is higher in high temperature resistance and wear resistance than red copper, and the service life of the contact tube is prolonged. The service life is prolonged; and the welding production efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of welding equipment, and in particular to a conductive nozzle of a double-protected welding gun. Background Art

[0002] At present, the double-guard welding machine is the most widely used welding process in the domestic welding field. It plays an important role in machinery manufacturing industry, construction industry, shipbuilding industry, new energy and aerospace industry. During the welding process of the double-guard welding gun, the conductive nozzle plays a key role in conducting current and transporting welding wire. During the double-guard welding process, the welding wire passes through the through hole of the conductive nozzle. When the surface of the welding wire is in contact with the conductive nozzle, a strong welding current is continuously transported to the welding wire through the conductive nozzle.

[0003] However, the existing two-shield welding machines all use copper as the main material to manufacture the two-shield welding gun conductive nozzle, and since the two-shield welding gun conductive nozzle is made of copper with a melting point of about 1000°C, the high-temperature arc generated when the welding wire rubs against the inner wall of the protective nozzle during welding is likely to stick the welding wire and the conductive nozzle together, resulting in the welding wire being unable to weld normally. Only by replacing the conductive nozzle or cleaning the conductive nozzle can the production efficiency be seriously affected and the production cost be increased. At the same time, during the welding production process, the inner wall of the conductive nozzle made of copper is very easy to cause wear when the high-current and high-temperature welding wire passes through, and the gap between the inner hole of the conductive nozzle and the welding wire becomes larger after wear, which makes it easier to generate a high-temperature arc, causing the adhesion of the welding wire and the conductive nozzle to intensify. In addition, the metal temperature of the molten pool during the welding production process is as high as about 2500 degrees, and part of it will splash onto the conductive nozzle. Since the melting point of copper is about 1000 degrees, the high-temperature spatter will firmly adhere to the conductive nozzle, causing blockage and affecting normal welding production.

[0004] In order to solve the above problems, the present invention adopts graphite as the main material to manufacture the conductive nozzle of the two-protection welding gun. Since the melting point of graphite is about 3800 degrees, the high-temperature arc generated by the welding wire and the inner wall of the conductive nozzle cannot melt the graphite conductive nozzle during the welding production process, thereby completely avoiding the adhesion of the welding wire and the conductive nozzle. In addition, due to the high melting point of graphite and the surface powdering characteristics at about 1000 degrees, the adhesion with high-temperature metal splashes is reduced. Even if there is a small amount of slag, it is very easy to clean, which greatly reduces the number and time of replacing and cleaning the conductive nozzle during the welding production process of the two-protection welding machine. At the same time, graphite is more resistant to high temperature and wear than copper, so the conductive nozzle made of graphite as the main material greatly improves its service life and welding production efficiency. Therefore, the development of a conductive nozzle of a two-protection welding gun has important practical significance. In order to solve the above problems, the present invention proposes a conductive nozzle of a two-protection welding gun. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a conductive nozzle of a double-protection welding gun which is resistant to high temperature, wear-resistant, easy to clean, strong in anti-breakage ability and low in cost.

[0006] In order to solve the above technical problems, the present invention is solved by the following technical solutions: a double-protection welding gun contact nozzle, comprising the following steps:

[0007] Step 1. Raw material selection: Generally, high-purity, high-crystallinity petroleum coke, asphalt coke, etc. are selected as the main raw materials, and coal tar is also used as a binder to ensure the quality of artificial graphite;

[0008] Step 2: Raw material pretreatment: crush and screen the raw materials to a certain particle size, and screen out particles that do not meet the particle size requirements. Then, pre-treat the raw materials by removing impurities and water to improve graphitization efficiency.

[0009] Step 3, batching and mixing: according to production requirements, mix raw materials of different particle sizes in proportion, add appropriate amount of binder, stir and mix thoroughly to make the raw materials and binder evenly distributed to ensure the quality of subsequent molding process;

[0010] Step 4, molding: the mixed raw materials are formed into a green body with a certain shape and size by vibration molding, extrusion molding, compression molding and isostatic pressing;

[0011] Step 5, calcination: put the green body into a calcination furnace, and heat it to about 800-1000°C under air-tight conditions to cause the binder to undergo pyrolysis and polycondensation reactions to form a coke network, which gives the green body a certain mechanical strength;

[0012] Step 6, graphitization: Place the calcined green body into a graphitization furnace and heat it to 2300-3000°C to transform the carbon atoms from a turbostratic structure to a graphite crystal structure;

[0013] Step 7: Make the blank: It is best to choose a graphite block with a density of 1.7g / cm 3 The above, the strength of the graphite protection nozzle made in this way can meet the use requirements. The selected graphite block can be cut into graphite sheets of appropriate thickness by wire saw or hacksaw. The graphite sheet is drilled into a cylindrical blank by a special multi-head hollow drill for standby use. The multi-head hollow drill is a special tool exclusively developed by our factory, which has the advantages of high production efficiency and low cost. The graphite sheet can also be processed into a cylindrical blank by wire sawing or lathe turning.

[0014] Step 8, finishing: clamp the graphite cylindrical blank onto the machine tool and obtain the graphite conductive nozzle body through turning, hole opening, tapping, threading, chamfering and other processes;

[0015] Step 9, assembly: Connect the outer threaded end of the processed graphite conductive nozzle with the inner threaded end of the copper tail end that has been processed in advance, and the complete graphite conductive nozzle is manufactured.

[0016] Preferably, the conductive nozzle of the double-protection welding gun is made of graphite as the main material, the melting point of the graphite is about 3800 degrees, and the conductive nozzle of the double-protection welding gun is a graphite conductive nozzle.

[0017] Preferably, the graphite contact nozzle comprises a graphite contact nozzle body and a contact nozzle copper tail end, and the graphite contact nozzle is composed of a combination of the graphite contact nozzle body and the contact nozzle copper tail end.

[0018] Preferably, a graphite conductive nozzle thread is provided at the end of the graphite conductive nozzle body, and an internal thread is provided inside the conductive nozzle copper tail end.

[0019] Preferably, the thread at the graphite conductive nozzle at the end of the graphite conductive nozzle body is adapted to the internal thread inside the copper tail end of the conductive nozzle, and the graphite conductive nozzle is formed by combining the thread at the graphite conductive nozzle at the end of the graphite conductive nozzle body with the internal thread inside the copper tail end of the conductive nozzle.

[0020] Preferably, a copper tail end external thread is provided on the outer side of the copper tail end of the conductive nozzle, and the copper tail end external thread on the outer side of the copper tail end of the conductive nozzle is connected to a red copper connecting rod.

[0021] Preferably, through holes are provided inside the graphite conductive nozzle body and the conductive nozzle copper tail end, the apertures of the graphite conductive nozzle body and the conductive nozzle copper tail end are consistent, and the apertures of the head, middle and tail of the graphite conductive nozzle are consistent.

[0022] Preferably, the graphite contact nozzle body is cylindrical, and its front end has a necking structure, and the graphite coating covers the inner surface of the necking structure.

[0023] Preferably, a connecting portion is provided at the rear end of the graphite contact nozzle body, the connecting portion is used to be connected to a conductive rod of a double-protection welding gun, and an insulating layer is provided on the outer surface of the connecting portion.

[0024] Preferably, the graphite has a high melting point and has surface powdering at about 1000 degrees. The graphite is more resistant to high temperatures and wear than copper.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The conductive tip of the double-welding gun of the present invention has a graphite with an ultra-high melting point of about 3800 degrees. During the double-welding welding production process, the high-temperature arc generated between the welding wire and the inner wall of the conductive tip has a temperature far lower than the melting point of graphite, so the graphite conductive tip cannot be melted, which fundamentally prevents the occurrence of the welding wire and the conductive tip sticking together, effectively guarantees the continuity and stability of the welding process, greatly reduces the welding interruption and subsequent processing procedures caused by sticking together, improves the fluency of the welding operation, and solves the problem that the conductive tip of the existing double-welding gun is easily stuck to the welding wire and is blocked by the splashing of high-temperature molten iron and slag;

[0027] 2. The graphite of the double-guard welding gun conductive nozzle of the present invention exhibits a surface powdering characteristic at about 1000 degrees, which greatly reduces the degree of adhesion between it and high-temperature metal splashes. Even if a small amount of slag is generated during the welding process, it can be easily cleaned without the need for complicated tools and processes, which not only reduces the difficulty of operation, but also reduces the time and labor costs consumed by cleaning the conductive nozzle, further improves the welding production efficiency, and makes full use of the high temperature resistance and wear resistance of graphite and the characteristic that the surface will be powdered at about 1000 degrees, which completely solves a major problem in the double-guard welding production process and greatly improves the welding production efficiency;

[0028] 3. Compared with the traditional copper conductive nozzle, the graphite conductive nozzle of the double-protection welding gun of the present invention has better high temperature resistance and wear resistance. In a long-term, high-intensity welding production environment, the graphite conductive nozzle can maintain a good working condition, effectively resist high temperature and friction loss, significantly extend its service life, reduce the frequency of frequent replacement of the conductive nozzle, reduce material costs and equipment downtime, enable welding production to operate efficiently and stably for a long time, bring higher economic and production benefits to the enterprise, and effectively promote the wide application and development of double-protection welding technology in related fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the three-dimensional structure;

[0030] Figure 2 This is a schematic diagram of the graphite conductive nozzle body structure;

[0031] Figure 3 This is a schematic diagram of the copper tail structure of the conductive nozzle;

[0032] Figure 4 It is a schematic diagram of the cross-sectional structure of a graphite contact nozzle;

[0033] Figure 5 It is a schematic diagram of the cross-sectional structure of the graphite conductive nozzle;

[0034] Figure 6 It is a schematic diagram of the cross-sectional structure of the copper tail end of the conductive nozzle. DETAILED DESCRIPTION

[0035] Unless the context clearly dictates otherwise, unmodified nouns and nouns modified by "the" include singular and plural referents.

[0036] As used in the specification and claims, the terms "comprises," "comprising," "having," "may," "containing," and variations thereof as used herein refer to open transitional phrases, terms, or words that require the presence of specified ingredients / steps and allow for the presence of other ingredients / steps. However, such descriptions should be interpreted as also describing compositions or methods as "consisting of" and "consisting essentially of" the recited ingredients / steps, which allows for the presence of only the specified ingredients / steps and any unavoidable impurities that may result therefrom, and excludes other ingredients / steps.

[0037] Numerical values ​​in the specification and claims of this application should be understood to include the same numerical values ​​when reduced to the same number of significant figures and numerical values ​​that differ from the stated value by less than the experimental error of ordinary measurement techniques of the type described in this application for determining the stated value.

[0038] All ranges disclosed herein are inclusive of the indicated endpoints and are independently combinable (eg, the range of "2 grams to 10 grams" includes the endpoints 2 grams and 10 grams, and all intermediate values).

[0039] The terms "about" and "approximately" can be used to include any numerical value that can be varied without changing the basic function of the value. When used with a range, "about" and "approximately" also disclose the range defined by the absolute values ​​of the two endpoints, for example, "about 2 to about 4" also discloses a range of "2 to 4". Generally, the terms "about" and "approximately" can refer to ±10% of the indicated number. However, for temperature, the term "approximately" refers to ±1°C.

[0040] Unless expressly stated otherwise, the percentages of elements are to be considered as percentages by weight of the alloy in question.

[0041] The present disclosure may refer to the temperature of certain method steps. It should be noted that these specifications generally refer to the temperature set by the heat source (such as a furnace), and not necessarily the temperature that the heated material must reach.

[0042] The following description is used to disclose the present invention and enable those skilled in the art to implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations. The basic principles of the present invention defined in the following description may be used for other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0043] Example 1

[0044] 1. Raw material preparation:

[0045] High-purity, fine-grained (5-15 micron) artificial graphite powder is selected as the basic raw material. This graphite powder has good conductivity and uniform physical properties. At the same time, an appropriate amount of binder, such as phenolic resin, is prepared, and its mass accounts for 5% to 10% of the graphite powder.

[0046] 2. Mixing:

[0047] Place the graphite powder and the binder in a high-speed mixer and stir at a speed of 800-1000 rpm for 30-45 minutes to ensure that the binder is evenly coated on the surface of the graphite powder particles to form a mixture with a certain viscosity.

[0048] 3. Molding:

[0049] The mixed material is placed in a precision mold. The mold cavity is designed according to the shape and size of the required conductive nozzle, with a tolerance controlled within ±0.05 mm. Cold isostatic pressing technology is used, with the pressure set at 150-200 MPa and the holding time of 1 to 2 minutes, so that the mixed material is formed into a conductive nozzle blank in the mold.

[0050] 4. Sintering:

[0051] The formed blank is placed in a vacuum sintering furnace for sintering. The sintering temperature is controlled at 800-1000℃, the heating rate is 5-10℃ / minute, and it is kept at the highest temperature for 2-3 hours to allow the binder to fully decompose and volatilize, while improving the strength and density of the graphite product. The density of the sintered product reaches 1.7-1.9 g / cm3.

[0052] 5. Machining:

[0053] The sintered conductive nozzle is machined using a high-precision CNC lathe. First, rough turning is performed with a cutting speed of 80-100 m / min and a cutting depth of 0.5-1 mm. The conductive nozzle blank is machined to a size close to the final size, leaving a finishing allowance of 0.1-0.2 mm. Then, fine turning is performed with the cutting speed increased to 120-150 m / min and a cutting depth of 0.05-0.1 mm. The inner hole and outer surface of the conductive nozzle are machined to the designed size, with the inner hole size tolerance controlled at ±0.01 mm and the outer surface roughness reaching Ra0.8-Ra1.6 microns.

[0054] 6. Surface treatment:

[0055] A layer of hard carbon film with a thickness of 5-10 microns is deposited on the inner hole surface of the conductive nozzle using chemical vapor deposition (CVD) technology to improve the wear resistance and conductivity of the inner hole, reduce the friction coefficient between the welding wire and the inner hole of the conductive nozzle, and further reduce the adhesion phenomenon.

[0056] Example 2

[0057] 1. Raw material selection and pretreatment:

[0058] Natural flake graphite is selected and purified to make the graphite purity reach more than 99%. The purified graphite is then crushed and classified, and graphite particles with a particle size of 10-20 microns are selected. A small amount of additives, such as silicon carbide powder (2% to 5% of the mass of graphite powder), are prepared to improve the hardness and wear resistance of the conductive nozzle.

[0059] 2. Mixing and kneading:

[0060] Fully knead the graphite particles, silicon carbide powder and an appropriate amount of liquid organic binder (such as epoxy resin) in a kneading machine for 60 to 90 minutes. The temperature is controlled at 40-50°C to evenly mix the components and form a mud with good plasticity.

[0061] 3. Extrusion molding:

[0062] The kneaded clay is placed into a screw extruder and extruded through a die of a specific shape and size. The extrusion pressure is 100-150 MPa and the extrusion speed is 5-10 mm / s to obtain a continuous conductive nozzle profile, which is then cut into individual conductive nozzle blanks according to the required length.

[0063] 4. Degreasing and sintering:

[0064] The conductive nozzle blank is placed in an atmosphere protection degreasing furnace for degreasing treatment at a temperature of 400-600°C for 3-5 hours to remove the organic components in the binder. The degreased blank is subjected to high-temperature graphitization treatment in a graphitization furnace at a temperature of 2500-3000°C for 1-2 hours to improve the crystallinity and performance stability of the graphite.

[0065] 5. Precision machining and testing:

[0066] The inner hole is precisely machined using electrospark machining technology. By controlling the discharge parameters, the inner hole size is machined to the design requirements, and the tolerance is controlled within ±0.005 mm. The size accuracy and shape accuracy of the conductive nozzle are detected in real time using an optical measuring instrument to ensure that the product quality meets high-precision requirements.

[0067] 6. Post-processing and packaging:

[0068] The processed conductive nozzle is cleaned to remove the processing debris and impurities on the surface, and then an anti-oxidation coating is applied on the surface of the conductive nozzle to prevent the graphite from being oxidized during storage and use. Finally, the conductive nozzle is packaged with anti-static plastic film as the packaging material. The quantity per package is determined according to customer needs, and the product specifications, model, production date and other information are marked on the packaging.

[0069] Example 3

[0070] Background of the Embodiments

[0071] In the existing field of the conductive nozzle technology of the two-way welding gun, the traditional conductive nozzle is mostly made of copper as the main material. Although copper has a certain conductivity, there are many problems in the welding process. Due to the frequent friction between the welding wire and the inner wall of the conductive nozzle and the effect of the high-temperature arc during welding, the copper conductive nozzle is easy to stick to the welding wire, which not only affects the welding quality, but also causes welding interruption, and requires frequent replacement or cleaning of the conductive nozzle. Moreover, after the high-temperature molten iron splashes onto the copper conductive nozzle, it is very easy to form slag and block the conductive nozzle, further reducing the conductivity and service life of the conductive nozzle, increasing the welding cost and time cost, and seriously affecting the welding production efficiency. Therefore, the present invention proposes to use graphite as the main material to manufacture the conductive nozzle of the two-way welding gun, aiming to solve the above problems.

[0072] Specific content of the embodiment

[0073] 1. Material selection and preparation

[0074] 1. Graphite material:

[0075] Select graphite raw materials with high purity and uniform particle size, whose graphite crystal structure is complete to ensure good conductivity and high temperature resistance. Select graphite powder with a purity of more than 95% and a particle size between 50-100 meshes.

[0076] 2. Additives (optional):

[0077] In order to further optimize the performance of the graphite contact nozzle, a small amount of antioxidants and reinforcing agents can be added. Antioxidants such as borides can effectively prevent the oxidation of graphite in high temperature environments, and the amount added is controlled at 1% to 3% of the total mass of graphite; reinforcing agents such as silicon carbide can improve the hardness and wear resistance of graphite, and the amount added is 2% to 5% of the total mass of graphite. The selected graphite raw materials and additives (if any) are fully mixed in a mixer for no less than 30 minutes.

[0078] 2. Molding process

[0079] 1. Mould design:

[0080] A special mold is designed according to the standard size of the conductive nozzle of the two-protection welding gun. The internal structure of the mold should ensure that the conductive nozzle after molding has precise inner diameter, outer diameter and length tolerances. For commonly used conductive nozzle specifications, the inner diameter tolerance is controlled at ±0.1mm, the outer diameter tolerance is controlled at ±0.2mm, and the length tolerance is controlled at ±0.5mm. The mold material is made of high-strength alloy steel, and the surface is finely polished to ensure that the surface of the conductive nozzle after molding is smooth and reduce the friction resistance to the welding wire.

[0081] 2. Molding method:

[0082] Using the cold isostatic pressing process, the mixed graphite material is loaded into an elastic mold, sealed and placed in the high-pressure chamber of the cold isostatic pressing equipment, and a pressure of 150-200MPa is applied for 10-15 minutes to make the graphite material evenly compressed and formed in all directions. The density of the green body after forming is uniform, and the relative density can reach 70% to 80%.

[0083] 3. Sintering treatment

[0084] 1. Sintering equipment and atmosphere:

[0085] The formed graphite contact nozzle blank is placed in a vacuum sintering furnace for sintering. The sintering atmosphere is protected by high-purity argon gas with a purity of not less than 99.99% to prevent graphite from being oxidized at high temperatures.

[0086] 2. Sintering temperature and time:

[0087] The sintering temperature is set between 2000-2500℃ and the sintering time is 2-3 hours. During the high-temperature sintering process, the internal structure of the graphite blank is further densified, the grains grow, and the mechanical strength and conductivity of the conductive nozzle are improved. After sintering, the density of the conductive nozzle can be increased to more than 90% to 95%.

[0088] 4. Machining and post-processing

[0089] 1. Machining:

[0090] The sintered graphite conductive nozzle is machined, including turning, grinding and other processes, to achieve the final design dimensional accuracy requirements. During the turning process, a sharp diamond tool is used, the cutting speed is controlled at 50-100m / min, the feed rate is 0.05-0.1mm / r, and the cutting depth is 0.1-0.2mm to ensure that the inner hole surface of the conductive nozzle is smooth without burrs and cracks.

[0091] 2. Post-processing:

[0092] The processed graphite conductive nozzle is subjected to surface treatment, such as resin impregnation or metal coating treatment. The impregnation resin can fill the pores of the graphite and improve its strength and oxidation resistance. The metal coating (such as nickel coating) can further improve the conductivity and wear resistance of the conductive nozzle. The impregnation resin can be phenolic resin or epoxy resin. The impregnation pressure is 0.5-1MPa and the impregnation time is 1-2 hours. The metal coating is electroplated or chemically plated, and the coating thickness is controlled at 10-20μm.

[0093] 3. Implementation Effect Verification

[0094] 1. Adhesion test:

[0095] The graphite conductive nozzle of the present invention was installed on a double-protected welding gun, and a comparative welding test was carried out with a traditional copper conductive nozzle under the same welding parameters (such as welding current, voltage, welding speed, etc.). After continuously welding 100 workpieces, the adhesion between the conductive nozzle and the welding wire was observed. The results showed that the copper conductive nozzle had 20 adhesion phenomena, while the graphite conductive nozzle of the present invention had no adhesion, which effectively solved the adhesion problem.

[0096] 2. Slagging test:

[0097] During the welding process, the slagging caused by the high-temperature molten iron splashing onto the conductive nozzle was observed. After 50 welding operations, the copper conductive nozzle had a large amount of slagging, which blocked part of the inner diameter of the conductive nozzle, affecting the stability of the welding current. However, the graphite conductive nozzle had only a small amount of slagging, which was loose and easy to clean, and had no obvious impact on the normal use of the conductive nozzle, significantly reducing the slagging blockage problem.

[0098] 3. Service life test:

[0099] Under normal production conditions, the graphite conductive nozzle and the copper conductive nozzle of the present invention are continuously used for welding operations, and the replacement cycle of the conductive nozzle is recorded. According to statistics, the copper conductive nozzle needs to be replaced once every 200 workpieces are welded on average, while the graphite conductive nozzle can still be used normally after welding 1000 workpieces, and its service life is greatly improved, which reduces the welding production cost and improves the welding production efficiency.

[0100] Embodiment 4: A double-protection welding gun contact tip, comprising the following steps:

[0101] 1. Raw material selection:

[0102] Generally, high-purity and high-crystallinity petroleum coke and asphalt coke are selected as the main raw materials, and coal tar is also used as a binder to ensure the quality of artificial graphite.

[0103] 2. Raw material pretreatment:

[0104] The raw materials are crushed and screened to a certain particle size, and particles that do not meet the particle size requirements are screened out. The raw materials are then pre-treated by impurity removal and water removal to improve graphitization efficiency;

[0105] 3. Ingredients and mixing:

[0106] According to production requirements, raw materials of different particle sizes are mixed in proportion, and an appropriate amount of binder is added. The mixture is fully stirred to ensure that the raw materials and the binder are evenly distributed to ensure the quality of the subsequent molding process;

[0107] 4. Molding:

[0108] The mixed raw materials are formed into a green body with a certain shape and size by means of vibration molding, extrusion molding, compression molding and isostatic pressing;

[0109] 5. Roasting:

[0110] The green body is placed in a roasting furnace and heated to about 800-1000°C under air-tight conditions to cause the binder to undergo pyrolysis and polycondensation reactions to form a coke network, which gives the green body a certain mechanical strength.

[0111] 6. Graphitization:

[0112] The calcined green body is placed in a graphitization furnace and heated to 2300-3000°C to transform the carbon atoms from a turbostratic structure to a graphite crystal structure;

[0113] 7. Making blanks:

[0114] The best choice of graphite block is the density of 1.7g / cm 3 The above, the strength of the graphite protection nozzle made in this way can meet the use requirements. The selected graphite block can be cut into graphite sheets of appropriate thickness by wire saw or hacksaw. The graphite sheet is drilled into a cylindrical blank by a special multi-head hollow drill for standby use. The multi-head hollow drill is a special tool exclusively developed by our factory, which has the advantages of high production efficiency and low cost. The graphite sheet can also be processed into a cylindrical blank by wire sawing or lathe turning.

[0115] 8. Finishing:

[0116] The graphite cylindrical blank is clamped on the machine tool and subjected to processes such as turning, hole opening, threading, threading, chamfering, etc. to obtain the graphite conductive nozzle body;

[0117] IX. Assembly:

[0118] Connect the outer threaded end of the processed graphite conductive nozzle to the inner threaded end of the copper tail end that has been processed in advance, and the complete graphite conductive nozzle is manufactured.

[0119] The specific steps are as follows: the staff generally selects high-purity, high-crystallinity petroleum coke, asphalt coke, etc. as the main raw materials, and also uses coal tar as a binder to ensure the quality of artificial graphite. At this time, the staff pre-treats the raw materials, crushes and screens the raw materials to a certain particle size, and screens out particles that do not meet the particle size requirements. After that, the raw materials are pre-treated by removing impurities and dehydrating to improve the graphitization efficiency. At this time, the staff mixes raw materials of different particle sizes in proportion according to production needs, and adds an appropriate amount of binder, fully stirs and mixes, so that the raw materials and binder are evenly distributed to ensure the quality of the subsequent molding process. The staff will make the mixed raw materials into a green body with a certain shape and size through vibration molding, extrusion molding, compression molding and isostatic pressing. The staff will then put the green body into a roasting furnace and heat it to about 800-1000℃ under air-tight conditions to make the binder undergo pyrolysis and polycondensation reactions to form a coke network, giving the green body a certain mechanical strength. The staff will then put the roasted green body into a graphitization furnace and heat it to 2300-3000℃ to transform the carbon atoms from a chaotic layer structure to a graphite crystal structure. The graphite block is preferably selected with a density of 1.7g / cm 3 The above, the strength of the graphite protective nozzle made in this way can meet the use requirements. The staff can select a good graphite block and cut it into graphite sheets of appropriate thickness through wire saws or hacksaws. The graphite sheets are drilled into cylindrical blanks for standby use through a special multi-head hollow drill. The multi-head hollow drill is a special tool exclusively developed by our factory, which has the advantages of high production efficiency and low cost. The graphite sheet can also be processed into cylindrical blanks by wire sawing or lathe turning. After the blank is processed, the staff will clamp the graphite cylindrical blank onto the machine tool and obtain the graphite conductive nozzle body through turning, hole opening, tapping, threading, chamfering and other processes. Finally, the staff will connect the outer threaded end of the processed graphite conductive nozzle body with the inner threaded end of the copper tail end that has been processed in advance, and the complete graphite conductive nozzle is manufactured.

[0120] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are only examples and do not limit the present invention. The purpose of the present invention has been fully and effectively achieved. The functions and structural principles of the present invention have been demonstrated and explained in the embodiments. Without departing from the principles, the embodiments of the present invention may be subject to any changes or modifications. Although the embodiments of the present invention have been shown and described, it is understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the attached claims and their equivalents. This specific embodiment is merely an explanation of the present application, and it is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without creative contributions as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A double-protection welding gun contact tip, characterized in that: The following steps are involved: Step 1. Raw material selection: Generally, high-purity, high-crystallinity petroleum coke, asphalt coke, etc. are selected as the main raw materials, and coal tar is also used as a binder to ensure the quality of artificial graphite; Step 2: Raw material pretreatment: crush and screen the raw materials to a certain particle size, and screen out particles that do not meet the particle size requirements. Then, pre-treat the raw materials by removing impurities and water to improve graphitization efficiency. Step 3, batching and mixing: according to production requirements, mix raw materials of different particle sizes in proportion, add appropriate amount of binder, stir and mix thoroughly to make the raw materials and binder evenly distributed to ensure the quality of subsequent molding process; Step 4, molding: the mixed raw materials are formed into a green body with a certain shape and size by vibration molding, extrusion molding, compression molding and isostatic pressing; Step 5, calcination: put the green body into a calcination furnace, and heat it to about 800-1000°C under air-tight conditions to cause the binder to undergo pyrolysis and polycondensation reactions to form a coke network, which gives the green body a certain mechanical strength; Step 6, graphitization: Place the calcined green body into a graphitization furnace and heat it to 2300-3000°C to transform the carbon atoms from a turbostratic structure to a graphite crystal structure; Step 7: Make the blank: It is best to choose a graphite block with a density of 1.7g / cm 3 The above, the strength of the graphite protection nozzle made in this way can meet the use requirements. The selected graphite block can be cut into graphite sheets of appropriate thickness by wire saw or hacksaw. The graphite sheet is drilled into a cylindrical blank by a special multi-head hollow drill for standby use. The multi-head hollow drill is a special tool exclusively developed by our factory, which has the advantages of high production efficiency and low cost. The graphite sheet can also be processed into a cylindrical blank by wire sawing or lathe turning. Step 8, finishing: clamp the graphite cylindrical blank onto the machine tool and obtain the graphite conductive nozzle body through turning, hole opening, tapping, threading, chamfering and other processes; Step 9, assembly: Connect the outer threaded end of the processed graphite conductive nozzle with the inner threaded end of the copper tail end that has been processed in advance, and the complete graphite conductive nozzle is manufactured.

2. A double-protection welding gun contact tip according to claim 1, characterized in that: The conductive nozzle of the two-way welding gun is made of graphite as the main material, the melting point of the graphite is about 3800 degrees, and the conductive nozzle of the two-way welding gun is a graphite conductive nozzle.

3. A double-protection welding gun contact tip according to claim 2, characterized in that: The graphite conductive nozzle comprises a graphite conductive nozzle body and a conductive nozzle copper tail end, and the graphite conductive nozzle is composed of a combination of the graphite conductive nozzle body and the conductive nozzle copper tail end.

4. A double-protection welding gun contact tip according to claim 3, characterized in that: The end of the graphite conductive nozzle body is provided with a graphite conductive nozzle thread, and the inside of the conductive nozzle copper tail end is provided with an internal thread.

5. A double-protection welding gun contact tip according to claim 4, characterized in that: The graphite conductive nozzle thread at the end of the graphite conductive nozzle body is adapted to the internal thread inside the conductive nozzle copper tail end, and the graphite conductive nozzle is formed by combining the graphite conductive nozzle thread at the end of the graphite conductive nozzle body with the internal thread inside the conductive nozzle copper tail end.

6. A double-protection welding gun contact tip according to claim 5, characterized in that: The outer side of the copper tail end of the conductive nozzle is provided with a copper tail end external thread, and the copper tail end external thread on the outer side of the copper tail end of the conductive nozzle is connected to the copper connecting rod.

7. A double-protection welding gun contact tip according to claim 6, characterized in that: The graphite conductive nozzle body and the conductive nozzle copper tail end are both provided with through holes, the apertures of the graphite conductive nozzle body and the conductive nozzle copper tail end are consistent, and the apertures of the head, middle and tail of the graphite conductive nozzle are consistent.

8. The double-protection welding gun contact tip according to claim 7, characterized in that: The graphite contact nozzle body is cylindrical, and its front end has a necking structure, and the graphite coating covers the inner surface of the necking structure.

9. A double-protection welding gun contact tip according to claim 8, characterized in that: A connecting portion is provided at the rear end of the graphite contact nozzle body, and the connecting portion is used to be connected to a conductive rod of a double-protection welding gun, and an insulating layer is provided on the outer surface of the connecting portion.

10. A double-protection welding gun contact tip according to claim 9, characterized in that: The graphite has a high melting point and has surface powdering at about 1000 degrees. The graphite is more resistant to high temperatures and wear than copper.

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