An automatic TIG welding apparatus and method suitable for a variety of groove angles

Abstract

The application discloses a kind of automatic TIG welding device and method suitable for various grooves.The device provided by the application includes a tungsten electrode;A protective gas nozzle is provided with a narrow gap structure at the lower part, which is used to spray protective gas;Connector, which is connected with the protective gas nozzle, can avoid welding short circuit;Gas distribution part, which is connected with the connector, is used to divide the welding gas into protective gas;Tungsten electrode clamping part, which extends into the gas distribution part, is used to fix and clamp the tungsten electrode;Gun body connecting part, which is connected with the gas distribution part, provides a channel for welding gas and tungsten electrode;And the main connector of the gun body is connected with the gun body connecting part, which provides the inlet of welding gas and tungsten electrode.The device of the application is easy to install, simple to operate, and has strong practicability, and has the ability of deep narrow gap groove backing welding, filling welding and cap welding, as well as flat surfacing without any change.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of pressure vessel manufacturing, in particular to an automatic TIG welding device and method suitable for various grooves. BACKGROUND

[0002] In the production process of the steam generator of Hualong No.1 product, the inner wall of the inlet pipe and the outlet pipe of the primary side loop needs to be cladded with a layer of high-temperature corrosion resistant stainless steel. The inlet pipe and the outlet pipe also need to be welded with a safety end pipe as a buffer. In order to ensure the welding quality, the weld between the safety end pipe and the primary side pipe is in the form of a narrow gap TIG welding groove. In order to reduce the filler metal, the groove is designed to be very narrow and deep, and the narrow gap automatic TIG welding is required to complete the welding of the whole weld with quality and quantity.

[0003] According to the welding rule of TIG welding, a special narrow gap TIG welding gun must be used to weld the narrow gap groove with deep welding. Otherwise, due to the limitation of the groove width, the welding gun cannot penetrate to the bottom of the weld for welding. When welding to a distance of about 25mm from the surface of the weld, the welding groove becomes shallow accordingly. Due to the limitation of the nozzle structure of the ordinary narrow gap TIG welding gun, the protective gas blown out by the gun cannot completely protect the welding pool, which easily causes defects such as welding porosity and oxidation of the welded metal, resulting in unqualified product welding. At present, when welding to a position of about 25mm, the narrow gap TIG welding gun needs to be removed and replaced with another cover welding gun (flat welding gun) to complete the subsequent welding. Due to the complexity of the TIG welding device itself, the replacement of the welding gun has certain operation difficulty and is very troublesome, which affects the welding efficiency. SUMMARY

[0004] In view of the problems existing in the prior art, the present application provides an automatic TIG welding device and method suitable for various grooves.

[0005] In order to achieve the above purpose, in the first aspect, the present application provides an automatic TIG welding device suitable for various grooves. The device comprises:

[0006] a tungsten electrode;

[0007] a protective gas nozzle, the lower part of which is provided with a narrow gap structure for blowing out protective gas;

[0008] a connector connected with the protective gas nozzle, which can avoid welding short circuit;

[0009] a gas distribution part connected with the connector for distributing the welding gas into protective gas;

[0010] a tungsten electrode clamping part extending into the gas distribution part for fixing and clamping the tungsten electrode;

[0011] A torch body connecting part connected with the equalizing part;

[0012] A torch body main connector connected with the torch body connecting part, providing a channel for the welding gas, welding current and the tungsten electrode, and conducting the shielding gas through the gap between the tungsten electrode and the torch body main connector.

[0013] In the second aspect, the present application provides an automatic TIG welding method suitable for various grooves, preferably implemented by using the automatic TIG welding device suitable for various grooves of the first aspect, which comprises the following steps:

[0014] S101, delivering the shielding gas through the equalizing part within a preset time before forming the welding arc and / or the welding pool;

[0015] S102, after forming the welding arc and / or the welding pool, automatically delivering the welding wire to the welding pool through the wire feeding tube and the wire feeding nozzle on the wire feeding holder, so as to realize the automatic TIG welding.

[0016] The automatic TIG welding device and method suitable for various grooves of the present application have the following beneficial effects:

[0017] (1) The device of the present application can realize deep narrow gap groove welding at one time without replacing any parts, and even complete the groove with a depth of 150 mm and a bottom width of ≥8 mm, avoiding the defect that the existing cap welding needs to replace the cap welding torch;

[0018] (2) The device of the present application can provide uniform and controllable shielding gas, avoid shielding gas flocculation, ensure the stability of the welding pool, and prevent the oxidation of the weld metal and the generation of pores and other defects;

[0019] (3) The device of the present application is easy to install, reduces the operation difficulty of the operator, and significantly improves the welding efficiency; and at the same time has the ability of deep narrow gap groove welding, filling welding and cap welding, and flat surfacing;

[0020] (4) The method of the present application can adjust the distance between the welding wire, the tungsten electrode and the workpiece at any time, so that the welding pool is more stable, the weld metal is uniform, and welding defects such as undercut and inclusion are avoided. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The structure schematic diagram of the automatic TIG welding device suitable for various grooves of the present application is shown;

[0022] Figure 2 The explosion structure schematic diagram of the automatic TIG welding device suitable for various grooves of the present application is shown;

[0023] Figure 3 The structure schematic diagram of the shielding gas nozzle of the present application is shown;

[0024] Figure 4 Fig. 1 shows a structural schematic diagram of a connector of the present application;

[0025] Figure 5 Fig. 2 shows a structural schematic diagram of a gas equalizing part of the present application;

[0026] Figure 6 Fig. 3 shows a structural schematic diagram of a torch connecting part of the present application;

[0027] Figure 7 Fig. 4 shows a structural schematic diagram of a wire feeding holder of the present application;

[0028] Figure 8 Fig. 5 shows a schematic diagram of the embodiment to realize narrow-gap TIG welding;

[0029] Figure 9 Fig. 6 shows a schematic diagram of the embodiment to realize automatic TIG flat surfacing.

[0030] Reference signs:

[0031] 1 - protection nozzle, 2 - connector, 3 - gas equalizing part, 3-1 - inner cylinder, 3-2 - outer cylinder, 4 - tungsten electrode clamping part, 5 - first heat-resistant sealing device, 6 - second heat-resistant sealing device, 7 - torch connecting part, 7-1 - first connecting cylinder, 7-2 - second connecting cylinder, 7-3 - third connecting cylinder, 8 - first heat-resistant ring, 9 - second heat-resistant ring, 10 - torch main connector, 11 - protection shell, 12 - tungsten electrode clamping top rod, 13 - tungsten electrode, 14 - welding wire, 15 - wire feeding nozzle, 16 - wire feeding tube, 17 - wire feeding holder, 18 - fixed top wire, 19 - narrow-gap workpiece, 20 - flat workpiece, 21 - water, electricity and gas connecting connector, 22 - water, electricity and gas collecting part, 23 - wire feeding holder connector A, 24 - micro cross slide, 25 - wire feeding holder connector B, 26 - tungsten electrode pressing nut, 27 - insulating sleeve, 28 - insulating plate. DETAILED DESCRIPTION

[0032] The preferred embodiments of the present application will be described in detail below with reference to the drawings, so that the advantages and features of the present application can be more easily understood by those skilled in the art, and the scope of protection of the present application can be more clearly defined.

[0033] It should be noted that, in this document, the terms "comprising", "containing", or any other variant thereof are intended to cover non-exclusive inclusions, so that a process, method, article or device that includes a list of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such a process, method, article or device. Without more limitations, the elements defined by the statement "comprising" do not exclude the presence of other identical elements in the process, method, article or device that includes the elements.

[0034] The narrow gap groove refers to a groove form with a depth-width ratio greater than or equal to 3. Such a groove structure requires the use of a special narrow gap TIG welding gun. However, when welding to a position of about 25 mm, the narrow gap TIG welding gun needs to be disassembled and replaced with another cover welding gun (flat welding gun) to complete the subsequent welding. The TIG welding gun replacement has certain difficulty, thereby affecting the welding efficiency.

[0035] Therefore, the present application provides an automatic TIG welding device and method suitable for various grooves. The device sets the lower part of the protective gas nozzle as a narrow gap structure through a stepped transition mode, which can effectively protect the tungsten electrode and the welding pool generated by the workpiece when the protective gas is sprayed in the deep narrow gap TIG welding groove and the flat surfacing, which is beneficial to ensure the welding quality.

[0036] In the first aspect, the present application provides an automatic TIG welding device suitable for various grooves. As shown in the figure, the device can mainly include: a protective gas nozzle 1, a connector 2, a gas equalizing part 3, a tungsten electrode clamping part 4, a gun body connecting part 7, a gun body main connector 10, and a tungsten electrode 13. Figures 1-7

[0037] In the present application, the gun body main connector 10, the gun body connecting part 7, the tungsten electrode clamping part 4, the gas equalizing part 3, the connector 2, and the protective gas nozzle 1 all have a cavity structure. The tungsten electrode 13, the welding gas or the protective gas can pass through the gun body main connector 10, the gun body connecting part 7, the tungsten electrode clamping part 4, the gas equalizing part 3, the connector 2, and the protective gas nozzle 1 in turn. At the same time, the tungsten electrode 13 extends to the outside of the protective gas nozzle 1, and the length of the tungsten electrode 13 extending out of the protective gas nozzle 1 is adjustable, which is suitable for grooves of different depths and has wide adaptability.

[0038] As shown in the figure, the protective gas nozzle 1 adopts a stepped transition mode to set the lower part as a narrow gap structure for spraying protective gas. Figure 2

[0039] Preferably, the upper part of the protective gas nozzle 1 can be cylindrical in shape to better connect with other parts.

[0040] As shown in the figure, 1 / 2-2 / 3 of the body of the protective gas nozzle 1 is set as a stepped shape. The step is at least one step, such as two steps, three steps or more steps. Figure 3

[0041] Preferably, the protective gas nozzle 1 is made of high-temperature resistant material, such as chromium, zirconium, or copper. In this way, the protective gas nozzle 1 has very strong high-temperature and ultraviolet radiation resistance.

[0042] ​​​The narrow gap structure of the lower part of the shielding nozzle 1 is similar to a rectangle, and has a cross-sectional area sufficient to pass a proper amount of shielding gas to protect the welding pool. At the same time, the shielding nozzle 1 can shorten the overall width to meet the welding requirements of deep narrow gap groove.

[0043] The narrow gap structure of the lower part of the shielding nozzle 1 has an inner width of 10-13 mm, an inner length of 30-40 mm, and a wall thickness of 0.5-1.5 mm. Preferably, the inner width is 10 mm, the inner length is 32 mm, and the wall thickness is 1 mm. The shielding nozzle 1 with the above size range can ensure the flow of shielding gas to protect the welding pool, and at the same time has the ability to perform backing welding, filling welding and cap welding, and flat surfacing of deep narrow gap groove.

[0044] In the present application, the connector 2 is connected with the shielding nozzle 1 to avoid welding short circuit, or is used alone as a shielding nozzle.

[0045] For example, the connector 2 can be provided with an inner and outer thread structure, i.e. the lower part is an external thread or an internal thread, and the upper part is opposite to the lower part structure, thereby facilitating installation. For example, the lower part of the connector 2 can be provided with an external thread, and the shielding nozzle 1 is provided with an internal thread.

[0046] The connector 2 needs to have insulation, heat resistance, and high rigidity. Therefore, the connector 2 is preferably made of ceramic insulating material, such as alumina.

[0047] The connector 2 can effectively prevent the welding current from passing through the shielding nozzle 1 and the workpiece to form a loop, thereby preventing the possibility of welding short circuit. At the same time, due to the characteristics of high temperature resistance, high hardness, and small expansion coefficient of the connector 2, the rigidity of the device is significantly improved.

[0048] As shown in Figure 4 The connector 2 is integrally formed by a plurality of cylinders with gradually changing sizes, for example, 3-6, specifically 4 or 5. Preferably, the inner diameter of the cylinder gradually increases from bottom to top, thereby facilitating compression or gathering of the shielding gas, making it enter the shielding nozzle 1 with a large pressure, and improving the protection effect.

[0049] For example, the connector 2 is provided with a boss at the top, and the lower part of the boss is provided with an external thread connected with the special shielding nozzle 1 and sealed with the second heat-resistant sealing device 6 to protect the shielding gas. The inner side of the connector 2 has an internal thread connected with the large external thread end of the gas equalizing part 3 through the thread; the small end of the gas equalizing part 3 has an external thread connected with the gun body connecting part 7; the gun body connecting part 7 is pressed against the first heat-resistant sealing device 5 through the lower edge plane, so that the shielding gas in the device is not leaked.

[0050] The upper part of the second heat-resistant ring 9 of the gun body connecting part 7 is provided with an external thread, connected with the gun body main connector 10, and the first heat-resistant ring 8 and the second heat-resistant ring 9 seal the protection gas, so that it is not leaked.

[0051] The first heat-resistant ring 8 and the second heat-resistant ring 9 are made of silica gel material, have a certain softness, and have the ability to withstand 250 DEG C high temperature for a long time.

[0052] The first heat-resistant sealing device 5 and the second heat-resistant sealing device 6 are made of polytetrafluoroethylene material, have moderate hardness, and have the ability to withstand 250 DEG C high temperature for a long time.

[0053] The ceramic insulated connector 2 is made of ceramic structure, has the characteristics of high temperature resistance and insulation;

[0054] The special protection gas nozzle 1 and the tungsten electrode 13 are insulated by the ceramic insulated connector 2 and the first heat-resistant sealing device 5, so that the current loop cannot be formed, so that when the special protection gas nozzle contacts the welding workpiece, the current loop cannot be formed, and the device cannot be burned, and the welding seam cannot be damaged, so that the quality accident can be avoided.

[0055] In the present application, the gas distribution part 3 is connected with the connector 2, and is used for distributing the welding gas into protection gas.

[0056] Exemplarily, the upper part of the connector 2 can be an internal thread structure, and is connected with the lower part of the gas distribution part 3.

[0057] As shown in Figure 5 The gas distribution part 3 includes an inner cylinder 3-1 and an outer cylinder 3-2, wherein the inner cylinder 3-1 is used for inserting the tungsten electrode 13, and the outer cylinder 3-2 is used for distributing the welding gas.

[0058] Specifically, the side wall of the inner cylinder 3-1 is provided with a gas passage hole 3-3. The gas passage hole 3-3 is used for discharging the welding gas entering the inner cylinder 3-1 into the outer cylinder 3-2.

[0059] The number and size of the gas passage hole 3-3 can be set according to the actual amount of welding gas entering, so as to efficiently discharge the welding gas in the inner cylinder 3-1 to the outer cylinder 3-2. Exemplarily, the number of the gas passage hole 3-3 is 4-8, for example, 6, and the gas passage hole 3-3 can be uniformly distributed. Preferably, the gas passage hole 3-3 can be a circular hole, or a non-circular hole, preferably a circular hole.

[0060] Exemplarily, the inner cylinder 3-1 can be integrally formed by a plurality of first intermediate cylinders with gradually changing sizes, for example, 2-5, for example, 3.

[0061] Exemplarily, the first intermediate cylinder has a diameter gradually increasing from bottom to top, i.e., the inner diameter of the lower part of the inner cylinder is smaller than that of the upper part.

[0062] Alternatively, the inner cylinder 3-1 is an inverted truncated cone. The inverted truncated cone refers to the inner diameter gradually decreasing from top to bottom along the axial direction of the truncated cone.

[0063] For example, the inner diameter of the lower part of the inner cylinder 3-1 is 1.01-1.1 times the diameter of the tungsten electrode, thereby facilitating the discharge of the welding gas.

[0064] Specifically, at least one layer of filter screen 3-4 is arranged in the cavity of the lower part of the outer cylinder 3-2.

[0065] Exemplarily, the number of layers of filter screens is 2-10, for example, 4-6; and the multiple layers of filter screens can be uniformly distributed.

[0066] For example, the mesh number of the filter screen is preferably 60-2200 meshes, and more preferably 80-1300 meshes, thereby being able to further filter the welding gas.

[0067] Exemplarily, the outer cylinder 3-2 can be integrally formed by multiple second intermediate cylinders with gradually changing sizes, for example, 2-5, for example, 2. Exemplarily, the inner diameter of the second intermediate cylinder gradually increases from bottom to top, i.e., the inner diameter of the lower part of the outer cylinder is smaller than that of the upper part, thereby more effectively dividing the welding gas.

[0068] Alternatively, the outer cylinder 3-2 is an inverted truncated cone. The inverted truncated cone refers to the inner diameter gradually decreasing from top to bottom along the axial direction of the truncated cone.

[0069] Among them, the outer cylinder 3-2 is arranged with multiple layers of dense filter screens, which can precisely divide the welding gas to produce stable protective gas suitable for protecting the welding pool.

[0070] In the present application, the tungsten electrode clamping part 4 extends into the gas equalizing part 3 for fixing and clamping the tungsten electrode 13.

[0071] Among them, the tungsten electrode clamping part 4 is gradually changed, the upper inner diameter is larger than the diameter of the tungsten electrode 13, and the lower inner diameter is smaller than the diameter of the tungsten electrode 13. The tungsten electrode clamping part has a slit at one end, extends into the inner hole of the gas equalizing part, and the end of the inner hole of the gas equalizing part has a tapered shrinkage hole. By applying force at the other end, the end of the tungsten electrode clamping part with the slit is pushed to the slope of the tapered shrinkage hole to cause shrinkage and extrusion deformation. The tungsten electrode is clamped and fixed by the shrinkage and extrusion force, i.e., by the pressing force applied to the tungsten electrode clamping part by the tungsten electrode clamping rod 12, the tungsten electrode clamping part is extruded with the gas equalizing part, the end of the tungsten electrode clamping part is deformed, thereby clamping the tungsten electrode. Preferably, at least one crack is arranged at the lower part of the tungsten electrode clamping part, and the outer wall of the lower part is chamfered, and the inner hole is slightly larger than the tungsten electrode by 0.1-0.2 mm; more preferably, 0.15 mm.

[0072] The tungsten electrode clamping part 4 has good electrical conductivity and can guide the welding current into the tungsten electrode 13, so that a stable welding arc is formed between the tungsten electrode 13 and the workpiece (including narrow gap workpiece 19 or flat workpiece 20, etc.).

[0073] In this invention, the gun body connecting part 7 is connected to the gas equalization part 3. Preferably, a small hole is opened on the side of the lower part of the gas equalization part connected to the tungsten electrode clamping part, which is not shown in the figure, to provide a gas passage.

[0074] For example, the upper part of the gas equalization section 3 can be a hollow cylindrical external thread structure, which is connected to the internal thread of the gun body connecting section 7.

[0075] like Figure 6 As shown, the gun body connecting part 7 may include a first connecting cylinder 7-1, a second connecting cylinder 7-2, and a third connecting cylinder 7-3. The inner diameter of the third connecting cylinder 7-3 is smaller than the inner diameter of the second connecting cylinder 7-2 and larger than the inner diameter of the first connecting cylinder 7-1. Each connecting cylinder is used to transmit current and gas.

[0076] The first connecting cylinder 7-1 is used to connect to the main connector 10 of the gun body; the second connecting cylinder 7-2 is used to expand the channel of welding gas; the third connecting cylinder 7-3 is used to connect to the gas equalization section 3.

[0077] To further secure the tungsten electrode 13, the tungsten electrode clamping part 4 can be extended into the third connecting cylinder 7-3.

[0078] Specifically, the first connecting cylinder 7-1 is provided with a concave annular structure, which is used for heat insulation and sealing.

[0079] The second connecting cylinder 7-2 can be configured as an irregular structure, preferably with grooves on both sides to facilitate tightening.

[0080] In this invention, the main connector 10 of the gun body is connected to the gun body connecting part 7, providing a channel for welding gas, welding current, and the tungsten electrode 13. Preferably, the protective gas is conducted through the gap between the tungsten electrode and the main connector of the gun body.

[0081] In this invention, the device also includes a protective shell 11, which is made of insulating material and covers the main connector 10 and the connecting part 7 of the gun body. The protective shell 11 has a certain rigidity and good insulation, and is used to protect the device.

[0082] In this invention, the device also includes a water, electricity and gas connector 21, which is connected to the main connector 10 of the gun body to provide channels for welding gas, welding current and tungsten electrode clamping rod;

[0083] The water collecting electrical part 22 is internally provided with a circulating water channel, and is provided with a passage for conveying welding gas to the gun body main connector and providing welding current, and transmits the compression force of the tungsten electrode clamp compression nut and the tungsten electrode clamp top rod; meanwhile, the device provides a fixed fulcrum;

[0084] The micro cross slide 24 is fixed on the water collecting electrical part through the wire feeder connector A23, and realizes the cross movement of the welding wire in the up-down and left-right directions relative to the tungsten electrode.

[0085] The welding wire conveying and holding part ensures that the welding wire is accurately conveyed to the specified position of the welding pool, and ensures the stable and continuous welding.

[0086] In the present application, the device further comprises a first heat-resistant sealing device 5 for sealing and protecting the gas nozzle 1 and the connector 2. Preferably, the sealing and protecting sleeve is connected at the connection part of the gas nozzle 1 and the connector 2.

[0087] In the present application, the device further comprises a second heat-resistant sealing device 6 for sealing and protecting the shell 11, the gun body connecting part 7 and the connector 2. Preferably, the sealing and protecting sleeve is connected at the connection part of the shell 11, the third connecting cylinder 7-3, the connector 2 and the protecting sleeve.

[0088] In the present application, the device further comprises a first heat-resistant ring 8 arranged at the connection part of the gun body connecting part 7 and the gun body main connector 10.

[0089] In the present application, the device further comprises a second heat-resistant ring 9 arranged on the gun body connecting part 7. Preferably, the second heat-resistant ring 9 is located at the concave ring on the first connecting cylinder 7-1.

[0090] In the present application, the device further comprises a tungsten electrode compression nut 26 screwed into the water and electrical base through threads, which generates the compression force of the tungsten electrode clamp top rod and is used for sealing the gas in the water and electrical base.

[0091] In the present application, the device further comprises a tungsten electrode clamp top rod 12 which can move and move into the gun body main connector 10 and the gun body connecting part 7, and is connected with the upper part of the tungsten electrode clamp part, so as to provide a pushing force to the inner cylinder slope of the gas equalizing part, so that the tungsten electrode clamp part deforms towards the tungsten electrode, and clamps the tungsten electrode.

[0092] The tungsten electrode clamp top rod 12 is provided with an inner hole for flowing the welding gas into the gun body main connector 10.

[0093] In the present application, the other functional components of the device are the same as the existing functional components, and will not be described in detail here.

[0094] In the present application, the device further comprises a wire feeding part. As shown in Figure 7 , the wire feeding part can include:

[0095] A welding wire 14 is located below the tungsten electrode 13; preferably, the distance between the welding wire 14 and the tungsten electrode 13 is 2-4 mm, so as to ensure that the welding wire can be stably melted in the welding pool.

[0096] A wire feeding nozzle 15 is used to stably feed the welding wire 14.

[0097] A wire feeding tube 16 is provided with the wire feeding nozzle 15 at one end, the welding wire 14 passes through the wire feeding tube 16 and the wire feeding nozzle 15 and extends to the outside of the wire feeding nozzle 15.

[0098] A wire feeding holder 17 is connected with the wire feeding tube 16 and used to fix the wire feeding tube 16.

[0099] Preferably, the wire feeding holder 17 is provided with a slant hole at the bottom, and the wire feeding tube 16 is fixed through the slant hole. The rest of the wire feeding holder 17 is a hollow thin-walled structure, so as to facilitate the installation of a camera or the observation of the state of the welding wire 14 fed into the welding pool and the state of the welding pool by the human eye.

[0100] As shown in the drawings, the wire feeding part can further comprise: Figure 6

[0101] A fixing top wire 18 is arranged on the wire feeding holder 17 and used to further fix the wire feeding tube 16.

[0102] More preferably, the wire feeding holder 17 is provided with a threaded hole at the vertical slant hole, the wire feeding tube 16 passes through the slant hole, and the fixing top wire 18 passes through the threaded hole, so as to fix the wire feeding tube 16.

[0103] In this way, the position of the welding wire 14 can be adjusted by the wire feeding tube 16 and the wire feeding holder 17.

[0104] The wire feeding part further comprises an insulation sleeve 27 and an insulation plate 28, which provide insulation for the welding wire and the welding arc.

[0105] A wire feeding holder connector A 23 is used to connect the micro cross slide part with the water, electricity and gas base and provide support for the micro cross slide.

[0106] A wire feeding holder connector B 25 provides connection and support for the welding wire feeding and holding part and the cross slide part.

[0107] A micro cross slide 24 is used to generate necessary up-down and left-right displacement of the welding wire feeding and holding part and other devices, control the position of the welding wire feeding at the tip of the tungsten electrode, and thus control the position of the welding wire feeding in the welding pool.

[0108] ​In the present application, the device can achieve deep narrow gap welding at one time without replacing any parts, even complete the groove with a depth of 150mm and a bottom width of ≥8mm, avoiding the defects of the existing device that needs to replace the surface welding gun when surface welding, while providing uniform and controllable protective gas, avoiding the flocculation of protective gas, ensuring the stability of the welding pool, preventing the oxidation of weld metal and the generation of pores and other defects.

[0109] In a second aspect, the present application provides an automatic TIG welding method suitable for various grooves, which uses the device of the first aspect for welding. It can include the following steps:

[0110] S101, within a preset time before the formation of the welding arc and / or the welding pool, the protective gas is delivered through the gas distribution part 3.

[0111] Among them, the welding gas flows into the gun body connecting part 7 and the gas distribution part 3 in turn through the inner hole of the tungsten electrode clamp top rod 12 and the gap of the tungsten electrode 13. The protective gas is obtained through at least one layer of filter screen in the middle of the gas distribution part 3. The protective gas flows into the protective gas nozzle 1 and is uniformly sprayed near the welding pool to protect the welding pool. The filter screen is made of stainless steel or nickel mesh, which is resistant to high temperature.

[0112] Preferably, the preset time can be determined according to the actual welding situation, preferably 5-30 seconds, for example 20 seconds, so as to completely protect the welding pool.

[0113] In the present application, the welding arc between the tungsten electrode 13 and the workpiece is controlled by an electric control system. The electric control system can gradually attenuate the welding arc and maintain it to a preset value, or stop welding.

[0114] Among them, the electric control system is selected from the existing electric control systems in the art, and the present application does not make specific limitations.

[0115] S102, after the formation of the welding arc and / or the welding pool, the welding wire 14 is automatically delivered to the welding pool through the wire feeding pipe 16 and the wire feeding nozzle 15 on the wire feeding holder 17 to realize automatic TIG welding.

[0116] In the present application, the delivery time and speed of the welding wire 14 can be set independently, regardless of whether the welding arc is formed, which can be set by the existing automatic wire feeding device, and the present application does not make specific limitations. For example, the delivery of the welding wire 14 can continue before the attenuation of the welding arc, or the amount of the welding wire 14 can be gradually reduced during the attenuation of the welding arc together with the welding arc.

[0117] Among them, after the welding arc between the tungsten electrode 13 and the workpiece is attenuated to the minimum maintained value or the welding arc is extinguished, a certain gas feeding time (lagging stop gas) can still be maintained, and the length of the lagging stop gas time is controllable, in order to achieve the purpose of protecting the completed weld.

[0118] In the present application, the method can adjust the distance between the welding wire and the tungsten electrode and the workpiece at any time, so that the welding pool is more stable, the weld metal is uniform, and welding defects such as undercut and inclusion are avoided. Meanwhile, the method is simple, reliable and widely applicable.

[0119] In order to further understand the present application, the device provided by the present application is described below in conjunction with examples, and the protection scope of the present application is not limited by the following examples. Examples

[0120] The narrow gap workpiece and the flat workpiece are welded, as shown in Figure 8 and 9 , wherein the depth of the narrow gap workpiece weld is 80 mm, the width is greater than 80 mm, the outer side of the deep groove is less than 23 mm, and the minimum weldable narrow groove is 10 mm;

[0121] The process of the automatic TIG welding device suitable for various grooves mainly includes: S101, 20 seconds before the welding arc and / or the welding pool is formed, the shielding gas is delivered through the gas distribution part 3.

[0122] The automatic TIG welding device suitable for various grooves includes: a shielding gas nozzle 1, a connector 2, a gas distribution part 3, a tungsten electrode clamping part 4, a first heat-resistant sealing device 5, a second heat-resistant sealing device 6, a gun body connecting part 7, a first heat-resistant ring 8, a second heat-resistant ring 9, a gun body main connector 10, a protective shell 11, a tungsten electrode clamping top rod 12, and a tungsten electrode 13.

[0123] The shielding gas nozzle 1 is set as a narrow gap structure by a two-step transition mode. The inner width of the narrow gap structure is 10 mm, the inner length is 32 mm, and the wall thickness is 1 mm.

[0124] The connector 2 is connected with the shielding gas nozzle 1. The upper part of the connector 2 is also wrapped with a protective sleeve.

[0125] The gas distribution part 3 is connected with the connector 2 and is used for dividing the welding gas into shielding gas. The gas distribution part 3 includes an inner cylinder 3-1 and an outer cylinder 3-2, wherein the inner cylinder 3-1 is used for inserting the tungsten electrode 13, and the outer cylinder 3-2 is used for dividing the welding gas. The side wall of the inner cylinder 3-1 is provided with six gas holes 3-3. Five layers of filter screens 3-4 are arranged in the cavity of the lower part of the outer cylinder 3-2.

[0126] The tungsten electrode clamping part 4 extends into the gas distribution part 3 and is used for fixing and clamping the tungsten electrode 13. The tungsten electrode clamping part 4 is tapered, the inner diameter of the upper part is greater than the diameter of the tungsten electrode 13, the inner diameter of the lower part is smaller than the diameter of the tungsten electrode 13, and the lower part is provided with three cracks.

[0127] The gun body connecting part 7 is connected with the gas equalizing part 3. The gun body connecting part 7 comprises a first connecting cylinder 7-1, a second connecting cylinder 7-2 and a third connecting cylinder 7-3. The first connecting cylinder 7-1 is used to connect with the gun body main connector 10; the second connecting cylinder 7-2 is used to expand the welding gas channel; the third connecting cylinder 7-3 is used to connect with the gas equalizing part 3.

[0128] The gun body main connector 10 is connected with the gun body connecting part 7. The protective shell 11 is made of insulating material.

[0129] The first heat-resistant sealing device 5 is used to seal the connection between the protective sleeve of the gas nozzle 1 and the connector 2.

[0130] The second heat-resistant sealing device 6 is used to seal the connection between the protective shell 11, the third connecting cylinder 7-3, the connector 2 and the protective sleeve.

[0131] The first heat-resistant ring 8 is arranged on the concave ring of the first connecting cylinder 7-1.

[0132] The second heat-resistant ring 9 is arranged at the connection between the gun body connecting part 7 and the gun body main connector 10.

[0133] The tungsten electrode clamp top rod 12 can move to the gun body main connector 10 and the gun body connecting part 7 to provide thrust to the tungsten electrode 13, so that the tungsten electrode clamp part 4 clamps the tungsten electrode 13.

[0134] S102, after forming the welding arc and / or the welding pool, the welding wire 14 is automatically fed into the welding pool through the wire feeding tube 16 and the wire feeding nozzle 15 on the wire feeding holder 17 to realize automatic TIG welding.

[0135] The automatic TIG welding device suitable for various grooves comprises a wire feeding part, which comprises a welding wire 14, a wire feeding nozzle 15, a wire feeding tube 16, a wire feeding holder 17 and a fixed top wire 18.

[0136] The welding wire 14 is located at the lower part of the tungsten electrode 13; the distance between the welding wire 14 and the tungsten electrode 13 is 3mm.

[0137] The wire feeding nozzle 15 is used to stabilize the feeding of the welding wire 14;

[0138] The wire feeding tube 16 is provided with a wire feeding nozzle 15 at the end; the welding wire 14 passes through the wire feeding tube 16 and the wire feeding nozzle 15 and extends to the outside of the wire feeding nozzle 15;

[0139] The wire feeding holder 17 is connected with the wire feeding tube 16;

[0140] The fixed top wire 18 is arranged on the wire feeding holder 17 and is used to fix the wire feeding tube 16.

[0141] After the completion of the planar workpiece welding, it is found that the protective gas has excellent protection effect on the high-temperature welding metal molten pool, the welded joint is smooth, no welding defects such as pores and slag inclusions are found by non-destructive testing, and the height of the welded joint is consistent with the workpiece. After the completion of the welding of the narrow gap workpiece without replacing the parts, it is found that the protective gas has excellent protection effect on the high-temperature welding metal molten pool, the welded joint is smooth, no welding defects such as pores and slag inclusions are found by non-destructive testing, and the height of the welded joint is consistent with the workpiece.

[0142] The above detailed description of the application is made in conjunction with specific embodiments and exemplary examples, but these descriptions cannot be understood as limiting the application. Those skilled in the art understand that various equivalent substitutions, modifications or improvements can be made to the technical solutions and embodiments of the application without deviating from the spirit and scope of the application, and these all fall within the scope of the application.

Claims

1. An automatic TIG welding device suitable for various bevels, characterized in that, include: Tungsten electrode; The protective nozzle has a narrow gap structure at the bottom for spraying protective gas. A connector, which connects to the protective gas nozzle, can prevent short circuits during welding; A gas equalization section, which is connected to the connector, is used to evenly distribute the welding gas into a protective gas; The tungsten electrode clamping part has a slit at one end, which extends into the inner hole of the gas equalization part; The gun body connecting part is connected to the gas equalization part; The main connector of the gun body is connected to the gun body connection part and provides a channel for welding gas, welding current and the tungsten electrode. The protective gas is conducted through the gap between the tungsten electrode and the main connector of the gun body. The lower part of the protective air nozzle is designed with a narrow gap structure using a stepped transition method. The narrow gap structure has an inner width of 10-13 mm, an inner length of 30-40 mm, and a wall thickness of 0.5-1.5 mm. It also includes: a tungsten electrode clamping rod, which can be moved into the main connector of the gun body and the gun body connecting part, and connected to the upper part of the tungsten electrode clamping part, providing the tungsten electrode clamping part with a push force to the ramp at the end of the inner hole of the gas equalization part. Since the end of the tungsten electrode clamping part pushes against the ramp at the end of the inner hole of the gas equalization part, the tungsten electrode clamping part deforms in the direction of the tungsten electrode, clamping the tungsten electrode. It also includes: a first heat-resistant sealing device for sealing the protective gas nozzle and the connector; It also includes: a wire feeding section, the wire feeding section comprising: Welding wire, which is located below the tungsten electrode; A wire feeder, used to stably feed the welding wire; A wire feeding tube, the end of which is fitted with the wire feeding nozzle, through which the welding wire passes; A wire feed holder, which is connected to the wire feed tube, is used to fix the wire feed tube.

2. The automatic TIG welding device applicable to various bevels according to claim 1, characterized in that, The gas equalization section includes an inner cylinder and an outer cylinder, wherein the inner cylinder is used to insert a tungsten electrode, and the outer cylinder is used to evenly distribute the welding gas.

3. The automatic TIG welding device applicable to various bevels according to claim 2, characterized in that, The inner cylinder has ventilation holes on its side wall; and / or At least one layer of filter screen is provided in the cavity at the bottom of the outer cylinder.

4. The automatic TIG welding device applicable to various bevels according to claim 1, characterized in that, The lower part of the tungsten electrode clamping part has at least one crack, and the outer wall of the lower part is chamfered.

5. The automatic TIG welding device applicable to various bevels according to claim 1, characterized in that, The gun body connecting part includes a first connecting cylinder, a second connecting cylinder, and a third connecting cylinder; wherein the first connecting cylinder is used to connect to the main connector of the gun body; the second connecting cylinder is used to expand the channel of welding gas; and the third connecting cylinder is used to connect to the gas equalization part.

6. An automatic TIG welding method applicable to various bevels, said method being implemented using the automatic TIG welding device applicable to various bevels as described in any one of claims 1 to 5, characterized in that, include: S101. Shielding gas is supplied through the gas equalization section within a preset time before the formation of the welding arc and / or the weld pool. S102. After the welding arc and / or welding pool are formed, the welding wire is automatically fed into the welding pool through the wire feeding tube and wire feeding nozzle on the wire feeding holder to realize automatic TIG welding.

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