Novel special welding ventilation protection device for cavity pipelines

Abstract

The invention relates to the technical field of welding protection, in particular to a novel cavity type pipeline special welding ventilation protection device which comprises a shell, an air inlet inner pipe, an air outlet outer pipe, a pressure regulating valve, a reducer union, a sealing piece, a ventilation cushion, a flow meter, a barometer, a rotational flow assembly, an airflow valve and a cooler. The air inlet inner pipe and the air outlet outer pipe are integrated, the time and cost for specially manufacturing an air outlet tool are reduced, protective gas is released along the bottom of the device, air in a cavity is gradually extruded upwards along the bottom through the protective gas in a rotational flow state, the air in the cavity enters the device along the air outlet in the cavity, and the air outlet efficiency is improved. And then the air is exhausted out of the device along the air outlet outer pipe, the phenomenon that the air is not exhausted thoroughly is reduced, the ventilation cushion is matched with the sealing piece, so that the influence of air pressure on the sealing piece is reduced when the pipeline cavity is filled with the protective gas, the sealing effect is improved, and gas outside the pipeline cavity is prevented from permeating.

Description

Technical Field

[0001] The present invention relates to the technical field of welding protection, and specifically to a special welding ventilation protection device for a new type of cavity pipeline. Background Art

[0002] During the pipeline welding process, the ventilation protection device plays a crucial role. When welding a pipeline, a protective gas is introduced into the pipeline to form an inert gas atmosphere in the welding area, isolating active gases such as oxygen and nitrogen in the air. This can effectively prevent the weld from being oxidized and nitrided at high temperatures, avoiding welding defects such as pores and inclusions, thereby ensuring the quality and performance of the weld. Cavity pipelines are widely used in fields such as aerospace, precision instruments, and chemical reaction devices. Their structures usually have complex characteristics such as multi-stage branches, irregular cross-sections, micro-pores or scattered holes. For example, in a fuel delivery system, a cooling pipeline, or a micro-reactor, the pipeline may include irregular holes, scattered holes, pinholes, multi-stage structures, etc. Currently, conventional pipeline welding ventilation protection mostly uses a simple gas pipe connected to both ends of the pipeline to expel air through the pressure of the gas, or first evacuates the pipeline to a vacuum and then releases the protective gas for ventilation, and continuously introduces the protective gas during the welding process for protection.

[0003] However, when performing link ventilation protection on cavity pipelines, due to the complex conditions such as irregular holes, scattered holes, pinholes, and multi-stage structures at the gas outlet end, it is impossible to introduce the protective gas through the conventional gas pipe connection method. When performing ventilation protection in this situation, due to the complex pipeline at the gas outlet end, air is often not exhausted completely, resulting in a certain amount of air remaining in the welding area, or due to the need to maintain the internal pressure of the cavity after the air is exhausted, the sealing effect is affected, resulting in the penetration of external air and affecting the welding quality. In the prior art, for the gas outlet of a complex cavity pipeline structure, special gas outlet tooling adapted to different complex structures needs to be specially manufactured for different gas outlet ends. However, since the gas outlet holes at the gas outlet end of cavity pipelines are often small in diameter and dispersed in distribution, not only is the gas outlet efficiency low and the ventilation process cumbersome, making it difficult to quickly and effectively form the coverage of the welding protection gas, but also additional costs are required and the process is complex.

[0004] Therefore, a special welding ventilation protection device for a new type of cavity pipeline is proposed. Summary of the Invention

[0005] The object of the present invention is to provide a special welding ventilation protection device for a new type of cavity pipeline, which solves the problems that when welding ventilation protection is carried out on complex cavity pipelines, the air discharge is not thorough, and in order to ensure the air pressure in the pipeline, the sealing effect is affected, resulting in the penetration of air outside the pipeline cavity and affecting the welding efficiency and quality of the pipeline; by integrating the intake inner pipe and the exhaust outer pipe, the time and cost of manufacturing a special exhaust tooling are reduced, the protective gas is released along the bottom of the device, and by making the protective gas squeeze the air in the cavity gradually upward along the bottom in a swirling state, the air in the cavity enters the device along the air discharge port in the cavity and then is discharged to the outside of the device along the exhaust outer pipe, reducing the phenomenon of incomplete air discharge, and through the ventilation pad cooperating with the sealing piece, the influence of air pressure on the sealing piece is reduced when the protective gas fills the inside of the pipeline cavity, and the sealing effect is increased to prevent the penetration of gas outside the pipeline cavity.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A special welding ventilation protection device for a new type of cavity pipeline, comprising a housing, an intake inner pipe, an exhaust outer pipe, a pressure regulating valve, a reducing joint, a sealing piece, a ventilation pad, a flow meter, a pressure gauge and a swirling component; the intake inner pipe and the exhaust outer pipe are connected through the reducing joint; there are two groups of pressure regulating valves, which are respectively connected to the intake inner pipe and the exhaust outer pipe; the housing is provided with a protective gas ventilation cavity, an air discharge port in the cavity, and a swirling passage connected to the protective gas ventilation cavity; the protective gas ventilation cavity is communicated with the intake inner pipe, the air discharge port in the cavity is communicated with the exhaust outer pipe, and the protective gas is discharged from the intake inner pipe to the protective gas ventilation cavity and enters the pipeline cavity in a swirling manner through the swirling passage.

[0008] It can be seen that in the prior art, when protecting the protective air in the pipeline, the air in the pipeline is usually discharged first, and then the protective gas is introduced to ensure the discharge of the air in the cavity. In the case of cavity pipelines, due to their complex structures, it is difficult to discharge the protective gas, and it is easy to produce the phenomenon of incomplete air discharge. By discharging the denser argon gas along the bottom of the device in a swirling manner into the pipeline cavity, the protective gas is separated from the air in the pipeline cavity by centrifugation, and a stable "air curtain" is formed under the orderly swirling, reducing the mixing of the protective gas and the air in the pipeline cavity, and squeezing the air in the cavity into the device along the air discharge port above the device and discharging it to the outside along the exhaust outer pipe, reducing the generation of air residue.

[0009] Preferably, the swirling component includes wedge-shaped guide vanes, telescopic guide vanes, a first arc-shaped telescopic rod, a second arc-shaped telescopic rod, a first spring, and an extrusion rod. There are several groups of wedge-shaped guide vanes, which are evenly arranged in a ring on the side of the air cushion close to the swirling passage. The wedge-shaped guide vanes are slidably connected to the telescopic guide vanes. The two ends of the first arc-shaped telescopic rod are respectively connected to the wedge-shaped guide vane and the air cushion. The two ends of the second arc-shaped telescopic rod are respectively connected to the telescopic guide vane and the air cushion. The two ends of the first spring are respectively connected to the wedge-shaped guide vane and the telescopic guide vane. The extrusion rod is connected to the inner wall of the wedge-shaped guide vane and passes through the telescopic guide vane. The length of the first arc-shaped telescopic rod is greater than that of the second arc-shaped telescopic rod. The telescopic lengths of the first arc-shaped telescopic rod and the second arc-shaped telescopic rod on the side along the swirling direction of the protective gas are greater than those of the first arc-shaped telescopic rod and the second arc-shaped telescopic rod on the other side. The sides of the wedge-shaped guide vane and the telescopic guide vane close to the center of the housing are arc-shaped inclined surfaces.

[0010] In the above solution, the protective air argon is introduced into the device along the intake inner pipe, and after passing through the swirling passage, it enters the pipeline cavity in a swirling state. At this time, the air cushion and the swirling component are located outside the swirling passage. The protective air will flow along the arc-shaped inclined surfaces of the wedge-shaped guide vane and the telescopic guide vane, and squeeze the wedge-shaped guide vane and the telescopic guide vane, so that the wedge-shaped guide vane and the telescopic guide vane gradually form an annular guide plate that slopes obliquely upward from the center of the housing to the outside by stretching the first arc-shaped telescopic rod and the second arc-shaped telescopic rod, making the swirling state of the protective gas intensify when flowing above the wedge-shaped guide vane and the telescopic guide vane, and making the protective gas flow upward in the direction of the pipeline intake end. By increasing the swirling state of the protective gas and increasing the centrifugal force of the swirling protective gas, it helps to separate the protective gas from the air in the cavity and generate a stable "air curtain", reducing the mixing of the protective gas and the air in the pipeline cavity.

[0011] Preferably, there are several groups of annularly and evenly distributed ventilation holes on the side of the air cushion close to the swirling passage. A gas blocking piece is arranged at the ventilation holes. A sliding plate is arranged on the side of the air cushion close to the center. A wedge-shaped extrusion plate is connected to the side of the gas blocking piece close to the outer ring of the air cushion. The wedge-shaped extrusion plate is connected to a second spring; a sliding rod is also arranged on the housing; the sliding plate is slidably connected to the sliding rod, and the number of ventilation holes is the same as that of the wedge-shaped guide vanes.

[0012] In the above solution, when the protective air continuously discharges into the cavity along the protective gas ventilation cavity and through the swirling passage, the protective gas accumulates below the air cushion far from the pipeline intake end, making the air pressure below the air cushion gradually increase. At this time, under the influence of the air pressure, the air cushion will slide along the sliding rod towards the sealing piece end through the sliding plate, thereby expanding the volume below the air cushion to balance the air pressure below the air cushion. And at the same time, the air cushion will squeeze the air above it to enter the inner cavity of the housing along the air discharge port in the cavity and be discharged to the outside through the air outlet outer pipe.

[0013] Preferably, a plurality of groups of air bags are arranged on the top of the ventilation pad and are evenly distributed in a ring shape. A placement groove corresponding to the air bag is arranged at the bottom of the sealing piece, and the axial length of the placement groove is shorter than the axial length of the air bag in the inflated state.

[0014] In the above solution, the ventilation pad will finally move to the sealing piece under the influence of air pressure. At this time, the sealing piece is gradually affected by the air pressure. When the ventilation pad moves to the sealing piece, the air bag will enter the placement groove. As the air bag gradually inflates, it will exert pressure on both sides of the sealing piece through the placement groove. Under the action of the pressure, the sealing effect of the sealing piece is increased. At this time, since the sealing piece is in close contact with the air cushion, the pressure on the sealing piece along the axial direction of the housing is reduced, and the pressure on the inner wall of the pipeline is increased through its own elasticity, thereby reducing the occurrence of air leakage caused by the sealing effect being affected by air pressure. At the same time, the ventilation pad is connected to the sealing piece through the air bag.

[0015] Preferably, a gas blocking plate is further arranged at the bottom of the air bag on the ventilation pad, a connecting ring connected to the gas blocking plate, and a third spring respectively connected to the gas blocking plate and the connecting ring; a wedge angle is arranged on the side of the gas blocking plate close to the housing; an unlocking groove longitudinally corresponding to the wedge angle is further arranged on the sealing piece; the gas blocking plate is slidably connected to the connecting ring. When the ventilation pad moves to one end of the sealing piece, the gas blocking plate is squeezed by the unlocking groove to make the air bag become ventilable.

[0016] In the above solution, when the ventilation pad moves upward to the bottom of the sealing piece, at this time, under the action of the unlocking groove, the wedge angle will be blocked and move towards the housing direction, so that the bottom of the air bag can be ventilated. At this time, an air bag with an axial length greater than the axial length of the placement groove in the inflated state can be used, so that the sealing piece is radially pressured by the placement groove in the inflated state of the air bag to ensure the sealing effect of the sealing piece.

[0017] Preferably, a hinge plate, a sealing plug connected to the hinge plate, and a C-shaped sleeve slidably connected to the outer wall of the housing are further arranged on the housing; a C-shaped column is arranged on the outer wall of the sealing plug; three groups of air discharge outlets in the cavity are longitudinally and evenly arranged, and the aperture of the sealing plug is the same as the aperture of the air discharge outlets in the cavity. When the sealing plug closes at the air discharge outlets in the cavity, the C-shaped sleeve and the C-shaped column are coaxial.

[0018] In the above solution, when the ventilation pad moves upward to the bottom of the sealing piece, at this time, the sealing piece will drive the C-shaped sleeve. When the C-shaped sleeve moves to the bottom of the sealing plug, it will squeeze the C-shaped column, so that the sealing plug generates transmission through the hinge plate until the C-shaped column and the C-shaped sleeve are coaxial. At this time, the sealing plug is at the air discharge outlets in the cavity, and the bottom air discharge outlets in the cavity are blocked by the sealing plug, so that the protective air is reduced from mixing with the air in the cavity.

[0019] Preferably, a plurality of groups of constant pressure holes communicating with the inner cavity of the housing are further provided on the housing, through holes having the same aperture as the constant pressure holes are further provided on the air cushion, the through holes communicate with the air vent holes, and an air flow valve is provided at the end of the air outlet outer tube.

[0020] In the above solution, when the air cushion moves upward to the bottom of the sealing piece and the protective gas is continuously introduced, the air in the remaining cavity is squeezed by the protective gas along the air vent holes, flows through the through holes and the constant pressure holes, and is discharged to the outside through the air outlet outer tube. After continuously introducing the protective gas for a period of time, the air in the cavity is reduced to the minimum value. Then, the air flow valve is closed to control the constant pressure of the protective gas in the cavity, making the welding process more stable.

[0021] Preferably, a cooler connected to the inner intake pipe is provided on one side of the flow meter.

[0022] In the above solution, when the protective gas is introduced, the protective gas is pre-cooled by the cooler, so that the protective gas further increases its own density when the temperature decreases, making the centrifugal separation between the protective gas and the air in the cavity more obvious in the swirling state, and reducing its own molecular activity, thereby reducing the mixing with the air. When welding, the temperature generated during welding is reduced by the cooled protective gas, which affects the welding stability.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] 1. The present invention provides a novel special welding ventilation protection device for cavity-type pipelines, integrating the inner intake pipe and the outer air outlet pipe. By inputting argon, a protective gas with a density larger than that of air, and pressurizing the protective gas along the bottom of the device through a pressure regulating valve and cooling it through a cooler, the protective gas enters the pipeline cavity. At this time, the protective air will have a greater density than the inner cavity gas, enter the pipeline cavity through the swirling passage, form a swirl inside the pipeline cavity, separate from the air in the cavity under the centrifugal force, and form a stable "air curtain" to reduce the mixing of the protective gas and the air in the cavity. By setting an air cushion, the upper air in the cavity is blocked from the protective gas, further preventing the mixing of the protective gas and the air in the cavity. After continuously introducing the protective gas, the air pressure at the bottom of the air cushion gradually increases and squeezes the air cushion to slide towards the sealing piece, squeezing the air in the cavity above the air cushion along the air outlet of the cavity air into the inner cavity of the housing and discharging it to the outside through the air outlet outer tube. Thus, it is not necessary to specially manufacture an air outlet tool adapted to different complex structures to continue discharging the air in the cavity, reducing the phenomenon of incomplete air discharge in the cavity pipeline due to complex situations, and thereby improving the welding quality.

[0025] 2. The present invention provides a novel ventilation protection device for special welding of cavity-type pipelines. Under the action of the pressure of the protective gas, the ventilation pad moves towards the sealing piece and closely adheres to the sealing piece. At this time, the sealing piece can maintain the air pressure in the cavity while blocking the air pressure acting along the axial direction of the housing through the ventilation pad. At the same time, under the action of the unlocking groove on the sealing piece, the air blocking plate displaces, so that the airbag becomes in a ventilable state. Under the action of the air pressure of the protective gas below the ventilation pad, the airbag will be filled, and thus the sealing piece is radially pressed through the placement groove, increasing the pressure of the sealing piece on the inner wall of the pipeline, further improving the sealing effect, preventing air penetration of the sealing piece affected by air pressure, and thus affecting the welding quality.

[0026] 3. The present invention provides a novel ventilation protection device for special welding of cavity-type pipelines. By setting a swirl component, when the protective gas is introduced into the cavity through the inner intake pipe, it will flow out in a swirling shape along the swirling passage at the bottom of the housing. At this time, the protective gas will push the swirl component to slide downward under the action of air pressure, thus acting as a deflector, intensifying the swirling state of the protective gas, and guiding the protective gas to rise towards the sealing piece. When the ventilation pad moves towards the sealing piece under the influence of air pressure, the swirl component gradually closes and adheres to the ventilation pad. Through the wedge shape of the swirl component, it promotes the stratification of the protective gas and the air in the cavity in the swirling state, further reducing the mixing of the protective gas and the air in the cavity. When the ventilation pad is squeezed to be close to the sealing piece, the air pressure of the protective gas continues to increase to squeeze the swirl component, opening the ventilation holes of the ventilation pad, continuing to exhaust the air in the cavity completely, and after reducing the air in the cavity to the lowest level, cooperating with the air flow valve to maintain the stable air pressure in the cavity, thereby improving the welding quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall structure of the novel ventilation protection device for special welding of cavity-type pipelines;

[0028] Figure 2 It is a schematic diagram of the cross-sectional structure of the housing of the novel ventilation protection device for special welding of cavity-type pipelines;

[0029] Figure 3 It is a schematic diagram of the connection relationship of the housing of the novel ventilation protection device for special welding of cavity-type pipelines;

[0030] Figure 4 It is a schematic diagram of the overall cross-sectional structure of the novel ventilation protection device for special welding of cavity-type pipelines;

[0031] Figure 5 It is for the novel ventilation protection device for special welding of cavity-type pipelines Figure 4 The enlarged schematic diagram at position A;

[0032] Figure 6 It is for the novel ventilation protection device for special welding of cavity-type pipelinesFigure 4 Schematic enlarged view at position B;

[0033] Figure 7 Schematic view of the ventilation completion state of the special welding ventilation protection device for new cavity pipelines;

[0034] Figure 8 Schematic view of the connection relationship between the C-shaped sleeve and the sealing plug of the special welding ventilation protection device for new cavity pipelines;

[0035] Figure 9 Schematic view of the unfolded state structure of the swirl component of the special welding ventilation protection device for new cavity pipelines;

[0036] Figure 10 Schematic sectional view of the swirl component of the special welding ventilation protection device for new cavity pipelines;

[0037] Figure 11 Schematic view of the usage process of the special welding ventilation protection device for new cavity pipelines;

[0038] Figure 12 For the special welding ventilation protection device for new cavity pipelines Figure 9 Schematic enlarged view at position C.

[0039] In the figure: 100, housing; 101, protective gas ventilation cavity; 102, air discharge port inside the cavity; 103, swirl passage; 200, intake inner pipe; 300, outlet outer pipe; 400, pressure regulating valve; 500, reducing joint; 600, sealing piece; 601, placement groove; 602, unlocking groove; 700, ventilation pad; 701, ventilation hole; 702, air blocking piece; 702-1, wedge-shaped extrusion plate; 702-2, second spring; 703, sliding plate; 704, airbag; 705, air blocking plate; 705-1, wedge-shaped angle; 706, connecting ring; 707, third spring; 708, through hole; 800, flowmeter; 900, pressure gauge; 1000, swirl component; 1001, wedge-shaped guide vane; 1002, telescopic guide vane; 1003, first arc-shaped telescopic rod; 1004, second arc-shaped telescopic rod; 1005, first spring; 1006, extrusion rod; 104, sliding rod; 105, hinge plate; 106, sealing plug; 106-1, C-shaped column; 107, C-shaped sleeve; 108, constant pressure hole; 1100, air flow valve; 1200, cooler. Detailed implementation manners

[0040] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following detailed description of the specific implementation manners of the present invention will be given in conjunction with the accompanying drawings of the specification.

[0041] In the following description, many specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can obtain other embodiments without departing from the spirit of the present invention and without creative efforts. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0042] Please refer to Figures 1 to 12 , the present invention provides the following technical solutions:

[0043] A novel cavity-type pipeline special welding ventilation protection device, comprising a housing 100, an intake inner pipe 200, an exhaust outer pipe 300, a pressure regulating valve 400, a reducing joint 500, a sealing sheet 600, a ventilation pad 700, a flow meter 800, a pressure gauge 900, and a swirl assembly 1000; the intake inner pipe 200 and the exhaust outer pipe 300 are connected through the reducing joint 500; there are two groups of pressure regulating valves 400, which are respectively connected to the intake inner pipe 200 and the exhaust outer pipe 300; the housing 100 is provided with a protective gas ventilation cavity 101, an air discharge port 102 in the cavity, and a swirl passage 103 connected to the protective gas ventilation cavity 101; the protective gas ventilation cavity 101 is communicated with the intake inner pipe 200, the air discharge port 102 in the cavity is communicated with the exhaust outer pipe 300, the protective gas is discharged from the intake inner pipe 200 to the protective gas ventilation cavity 101 and enters the pipeline cavity in a swirl through the swirl passage 103, so that the air in the cavity enters the exhaust outer pipe 300 along the air discharge port 102 in the cavity and is discharged to the outside of the device, reducing the phenomenon of incomplete air discharge, and through the cooperation of the ventilation pad 700 and the sealing sheet 600, when the protective gas fills the inside of the pipeline cavity, the influence of the air pressure on the sealing sheet 600 is reduced, enhancing the sealing effect and preventing the penetration of the gas outside the pipeline cavity. It should be noted that in order to make the protective gas more convenient to generate centrifugal separation from the gas in the cavity in a swirling state, argon with a density greater than that of air can be used as the protective gas here.

[0044] As an embodiment of the present invention, referring to Figure 2 , Figure 7 , Figure 9 , Figure 10 , Figure 11 and Figure 12, the swirl component 1000 includes wedge-shaped guide vanes 1001, telescopic guide vanes 1002, first arc-shaped telescopic rods 1003, second arc-shaped telescopic rods 1004, first springs 1005, and extrusion rods 1006. The wedge-shaped guide vanes 1001 are provided with several groups evenly distributed in a ring on the side of the air cushion 700 close to the swirl passage 103, and are slidably connected to the telescopic guide vanes 1002. Both ends of the first arc-shaped telescopic rod 1003 are respectively connected to the wedge-shaped guide vane 1001 and the air cushion 700. Both ends of the second arc-shaped telescopic rod 1004 are respectively connected to the telescopic guide vane 1002 and the air cushion 700. Both ends of the first spring 1005 are respectively connected to the wedge-shaped guide vane 1001 and the telescopic guide vane 1002. The extrusion rod 1006 is connected to the inner wall of the wedge-shaped guide vane 1001 and passes through the telescopic guide vane 1002. The length of the first arc-shaped telescopic rod 1003 is greater than that of the second arc-shaped telescopic rod 1004. The telescopic lengths of the first arc-shaped telescopic rod 1003 and the second arc-shaped telescopic rod 1004 on the side along the swirl direction of the protective gas are greater than those on the other side. The sides of the wedge-shaped guide vane 1001 and the telescopic guide vane 1002 close to the center of the housing 100 are arc-shaped inclined surfaces. The protective gas is introduced into the device along the intake inner pipe 200, and after passing through the swirl passage 103, it enters the pipeline cavity in a swirling state. The air cushion 700 and the swirl component 1000 are located outside the swirl passage 103. The protective gas flows along the arc-shaped inclined surfaces of the wedge-shaped guide vane 1001 and the telescopic guide vane 1002 and squeezes the two, so that the wedge-shaped guide vane 1001 and the telescopic guide vane 1002 gradually form an annular guide plate obliquely upward from the center of the housing 100 to the outside by stretching the first arc-shaped telescopic rod 1003 and the second arc-shaped telescopic rod 1004, intensifying the swirling state of the protective gas and flowing upward in the direction of the pipeline intake end, increasing the swirling centrifugal force of the protective gas, helping the protective gas to separate from the air in the cavity, and forming a stable "air curtain" to reduce mixing.

[0045] As an implementation manner of the present invention, referring to Figure 4 and Figure 11 , several groups of annularly and evenly distributed ventilation holes 701 are provided on the side of the air cushion 700 close to the swirl passage 103. Air blocking sheets 702 are provided at the ventilation holes 701. A sliding plate 703 is provided on the side of the air cushion 700 close to the center of the circle. A wedge-shaped extrusion plate 702-1 is connected to the side of the air blocking sheet 702 close to the outer ring of the air cushion 700. The wedge-shaped extrusion plate 702-1 is connected to a second spring 702-2; a sliding rod 104 is also provided on the housing 100; the sliding plate 703 is slidably connected to the sliding rod 104, and the ventilation holes 701 are provided in the same number of groups as the wedge-shaped guide vanes 1001; when the protective gas continues to be discharged into the cavity, the air pressure below the air cushion 700 increases. Under the action of the air pressure, the air cushion 700 slides along the sliding rod 104 towards the sealing sheet 600 through the sliding plate 703, expanding the volume below the air cushion 700 to balance the air pressure, and at the same time squeezing the upper air to enter the inner cavity of the housing 100 along the air discharge port 102 in the cavity and being discharged by the air outlet outer pipe 300.

[0046] As an embodiment of the present invention, referring to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 8 , a plurality of groups of air bags 704 evenly distributed in a ring shape are arranged on the top of the ventilation pad 700, a placement groove 601 corresponding to the air bag 704 is arranged at the bottom of the sealing piece 600, and the axial length of the placement groove 601 is shorter than the axial length of the air bag 704 in the inflated state; when the ventilation pad 700 is moved to the sealing piece 600, the air bag 704 enters the placement groove 601, and the inflated air bag 704 generates pressure on both sides of the sealing piece 600 through the placement groove 601. Under the pressure, the sealing effect of the sealing piece 600 is increased, and the air leakage phenomenon caused by the influence of air pressure is reduced. The ventilation pad 700 is connected to the sealing piece 600 through the air bag 704. It should be noted that the position of the air bag 704 does not coincide with the position of the ventilation hole 701, and the protective gas can enter the inner cavity of the ventilation pad 700 along the ventilation hole 701 and enter the air bag 704.

[0047] As an embodiment of the present invention, referring to Figure 6 and Figure 7 , a gas blocking plate 705 located at the bottom of the air bag 704, a connecting ring 706 connected to the gas blocking plate 705, and a third spring 707 respectively connected to the gas blocking plate 705 and the connecting ring 706 are further arranged on the ventilation pad 700; a wedge angle 705-1 is arranged on one side of the gas blocking plate 705 close to the housing 100; an unlocking groove 602 longitudinally corresponding to the wedge angle 705-1 is further arranged on the sealing piece 600; the gas blocking plate 705 is slidably connected to the connecting ring 706. When the ventilation pad 700 is moved to one end of the sealing piece 600, the gas blocking plate 705 is squeezed by the unlocking groove 602 to make the air bag 704 in a ventilable state; when the ventilation pad 700 moves upward to the bottom of the sealing piece 600, the unlocking groove 602 blocks the wedge angle 705-1 to move it in the direction of the housing 100, and the bottom of the air bag 704 can be ventilated. The air bag 704 with an inflated state axial length greater than the axial length of the placement groove 601 applies radial pressure to the sealing piece 600 through the placement groove 601 to ensure the sealing effect.

[0048] As an embodiment of the present invention, referring to Figure 7 and Figure 8, a hinge plate 105, a sealing plug 106 connected to the hinge plate 105, and a C-shaped sleeve 107 slidably connected to the outer wall of the housing 100 are further provided on the housing 100; a C-shaped column 106-1 is provided on the outer wall of the sealing plug 106; three groups of cavity air discharge ports 102 are longitudinally and uniformly provided, the aperture of the sealing plug 106 is the same as that of the cavity air discharge port 102, and when the sealing plug 106 is closed at the cavity air discharge port 102, the C-shaped sleeve 107 is coaxial with the C-shaped column 106-1; when the ventilation pad 700 moves upward to the bottom of the sealing piece 600, the C-shaped sleeve 107 moves to the bottom of the sealing plug 106 and presses the C-shaped column 106-1, and the sealing plug 106 is transmitted through the hinge plate 105 until the C-shaped column 106-1 is coaxial with the C-shaped sleeve 107, and the sealing plug 106 is at the cavity air discharge port 102 to block the bottom cavity air discharge port 102, reducing the mixing of the protective air and the cavity air.

[0049] As an embodiment of the present invention, referring to Figure 1 , Figure 2 and Figure 7 , a plurality of groups of constant pressure holes 108 communicating with the inner cavity of the housing 100 are further provided on the housing 100, through holes 708 having the same aperture as the constant pressure holes 108 are further provided on the ventilation pad 700, the through holes 708 communicate with the ventilation holes 701, and an air flow valve 1100 is provided at the end of the air outlet outer tube 300; when the ventilation pad 700 moves to the bottom of the sealing piece 600, the remaining cavity air flows through the air outlet outer tube 300 along the ventilation holes 701, the through holes 708 and the constant pressure holes 108 and is discharged, and the air flow valve 1100 is closed after continuously introducing the protective gas to reduce the air in the cavity to the minimum value to control the pressure of the protective gas in the cavity to be constant and stabilize the welding process.

[0050] As an embodiment of the present invention, referring to Figure 2 , Figure 6 and Figure 7 , a cooler 1200 connected to the intake inner tube 200 is provided on one side of the flow meter 800; when introducing the protective gas, the protective gas is cooled by the cooler 1200 to increase the density, improve the centrifugal separation effect with the air in the cavity, reduce the molecular activity and the mixing degree with the air, and reduce the influence of too high temperature during welding on the welding stability.

[0051] Working principle: The protective gas is input through the starting device. The protective gas enters the interior of the pipeline cavity through the inner intake pipe 200, and is discharged along the protective gas ventilation cavity 101 at the bottom of the housing 100. After flowing through the swirl passage 103, in the pipeline cavity in a swirling state, the protective gas squeezes the swirl assembly 1000 to open through air pressure, and under the guiding action after the swirl assembly 1000 opens, the swirling state of the protective gas is intensified. After continuously inputting the protective gas, the air cushion 700 is pushed to move towards the sealing piece 600 through air pressure extrusion. The air cushion 700 gradually squeezes the air in the pipeline cavity upwards. The air enters the inner cavity of the housing 100 along the air discharge port 102 in the cavity and is discharged to the outside through the outer air outlet pipe 300. During the process of inputting the protective gas, the air pressure below the air cushion 700 increases, pushing the air cushion 700 to slide upwards to make it close to the sealing piece 600. At this time, the air blocking plate 705 is squeezed by the unlocking groove 602, making the airbag 704 become in a ventilable state. The airbag 704 is filled under the action of air pressure and presses on the sealing piece 600 through the placement groove 601 to enhance the sealing effect. Finally, the protective gas fills the pipeline cavity, and the air in the cavity is discharged to complete the ventilation protection, thereby improving the welding quality.

[0052] Specifically: First, seal the pipeline aperture of the pipeline cavity through the prior art. Connect the housing 100 and its connecting part to the pipeline cavity along the pipeline opening until the sealing piece 600 is located at the bottom of the pipeline. When inputting the protective gas, the protective gas is input into the inner cavity of the housing 100 through the inner intake pipe 200 and flows into the interior of the pipeline cavity through the protective gas ventilation cavity 101 on the housing 100. After flowing through the swirl passage 103, it enters the pipeline cavity in a swirling state. At this time, the protective gas enters the interior of the pipeline cavity in a state of being pressurized by the pressure regulating valve 400 and cooled by the cooler 1200. After being pressurized and cooled, the density of the protective gas itself increases. When swirling into the interior of the pipeline cavity, under the action of swirl centrifugation, the protective gas with a larger density forms a layer separation from the air in the pipeline cavity through centrifugation, thereby reducing the mixing with the air in the pipeline cavity. At the same time, under the action of air pressure, the initially entered protective air in the pipeline cavity will flow along the arc-shaped inclined surfaces of the wedge-shaped guide vane 1001 and the telescopic guide vane 1002, and squeeze the wedge-shaped guide vane 1001 and the telescopic guide vane 1002, so that the wedge-shaped guide vane 1001 and the telescopic guide vane 1002 gradually form an annular guide plate obliquely upward from the center of the housing 100 to the outside by stretching the first arc-shaped telescopic rod 1003 and the second arc-shaped telescopic rod 1004, making the protective gas flow above the wedge-shaped guide vane 1001 and the telescopic guide vane 1002 to intensify the swirling state of the protective gas and making the protective gas flow in an upward state towards the pipeline intake end.

[0053] Continuously introduce a protective gas. The protective gas will gradually fill the pipe cavity space below the air cushion 700 along one side of the protective gas venting cavity 101. At this time, the air pressure in the area below the air cushion 700 gradually increases, causing the air cushion 700 to slide axially along the sliding rod 104 through the sliding plate 703. And the wedge-shaped deflector 1001 and the telescopic deflector 1002 will reattach to the air cushion 700 under the action of the springs and air pressure inside the first arc-shaped telescopic rod 1003 and the second arc-shaped telescopic rod 1004. At this time, under the action of the wedge-shaped arc surface at the bottom of the wedge-shaped deflector 1001, it will promote the centrifugal separation state of the protective gas rising towards the sealing piece 600 in the swirling flow and the air in the pipe cavity, further preventing the mixing of the protective gas and the air in the pipe cavity. At this time, the air cushion 700 will move towards the sealing piece 600 and drive the C-shaped sleeve 107 to move upward during the movement. When the air cushion 700 moves to the bottom of the sealing plug 106, it will push the bottom of the sealing plug 106, causing the sealing plug 106 to rotate along the hinge plate 105. At the same time, the C-shaped sleeve 107 will simultaneously squeeze the C-shaped column 106-1 until the sealing plug 106 closes to the cavity air outlet 102. At this time, the C-shaped sleeve 107 continues to move upward under the drive of the air cushion 700. The C-shaped sleeve 107 will be located on one side of the C-shaped column 106-1 at this time, thus limiting the sealing plug 106. Since the outer wall of the housing 100 is an arc surface, when the sealing plug 106 closes to the cavity air outlet 102, it will not cause absolute sealing of the cavity air outlet 102. At this time, under the action of the protective gas pressure, a part of the protective gas will enter the inside of the housing 100 along the cavity air outlet 102 and squeeze the air in the pipe cavity towards the outlet outer pipe 300 under the action of the protective gas, promoting the discharge of the air in the cavity.

[0054] When the protective air fills the pipeline cavity, the air cushion 700 continuously slides towards the sealing piece 600 until the air cushion 700 is in close contact with the sealing piece 600. When the air cushion 700 approaches the sealing piece 600, the through hole 708 on the air cushion 700 will gradually coincide with the constant pressure hole 108. At this time, during the process of continuously introducing the protective gas, the air pressure below the air cushion 700 away from the sealing piece 600 will continue to increase. When the air pressure is greater than the elastic force of the first spring 1005, it will squeeze the wedge-shaped guide vane 1001 to contract towards the telescopic guide vane 1002. At this time, the wedge-shaped guide vane 1001 and the telescopic guide vane 1002 gradually coincide. The wedge-shaped guide vane 1001 passes through the telescopic guide vane 1002 through the extrusion rod 1006 and squeezes towards the wedge-shaped pressing plate 702-1, driving the air blocking piece 702 to displace towards the second spring 702-2. At this time, the gas can flow into the ventilation hole 701. The continuous introduction of gas below the air cushion 700 will flow along the ventilation hole 701 through the air cushion 700 and flow to the inner cavity of the housing 100 along the through hole 708. Under the swirling state below the air cushion 700, the air in the pipeline cavity will be more likely to enter the ventilation hole 701 and be discharged to the outside of the cavity through the air outlet outer pipe 300. Continuously introducing the protective gas to exhaust the air in the pipeline cavity to the lowest level, then the air flow valve 1100 can be closed to reduce the flow rate of the protective gas, and cooperate with the pressure regulating valve 400 to adjust the pressure in the pipeline cavity to be stable, thereby improving the welding quality.

[0055] When the air cushion 700 is in close contact with the sealing piece 600, the air pressure at the sealing piece 600 will be blocked by the air cushion 700, thereby reducing the influence of the air pressure on the sealing piece 600 and preventing sealing leakage caused by increased pressure. At the same time, the air blocking plate 705 is squeezed by the unlocking groove 602, so that the air blocking plate 705 squeezes the third spring 707 and moves towards the housing 100, thereby releasing the sealing effect on the bottom of the airbag 704 and making the airbag 704 in a ventilable state. The airbag 704 is filled under the action of the air pressure. At this time, the airbag 704 will radially press the sealing piece 600 through the placement groove 601, and the sealing piece 600 will increase the pressure on the inner wall of the pipeline, thereby enhancing the sealing effect.

[0056] The above embodiments are only used to illustrate some examples of the feasible technical solutions of the present invention rather than limiting the embodiments. The present invention can be understood in more detail with reference to the embodiments. Those skilled in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A special welding ventilation protection device for a new type of cavity pipeline, characterized in that: It includes a housing (100), an inner intake pipe (200), an outer exhaust pipe (300), a pressure regulating valve (400), a reducing joint (500), a sealing piece (600), a ventilation pad (700), a flow meter (800), a pressure gauge (900) and a swirl assembly (1000); the inner intake pipe (200) is connected to the outer exhaust pipe (300) through the reducing joint (500); there are two groups of the pressure regulating valves (400), which are respectively connected to the inner intake pipe (200) and the outer exhaust pipe (300); the housing (100) is provided with a protective gas ventilation chamber (101), an air discharge port (102) inside the chamber, and a swirl passage (103) connected to the protective gas ventilation chamber (101); the protective gas ventilation chamber (101) is communicated with the inner intake pipe (200), the air discharge port (102) inside the chamber is communicated with the outer exhaust pipe (300), and the protective gas is discharged from the inner intake pipe (200) to the protective gas ventilation chamber (101) and enters the pipeline cavity in a swirl through the swirl passage (103).

2. The special welding ventilation protection device for a new type of cavity pipeline according to claim 1, characterized in that: The swirl assembly (1000) includes wedge-shaped guide vanes (1001), telescopic guide vanes (1002), a first arc-shaped telescopic rod (1003), a second arc-shaped telescopic rod (1004), a first spring (1005), and an extrusion rod (1006). There are several groups of the wedge-shaped guide vanes (1001), which are arranged in a ring and evenly on one side of the ventilation pad (700) close to the swirl passage (103). The wedge-shaped guide vanes (1001) are slidably connected to the telescopic guide vanes (1002). Two ends of the first arc-shaped telescopic rod (1003) are respectively connected to the wedge-shaped guide vanes (1001) and the ventilation pad (700). Two ends of the second arc-shaped telescopic rod (1004) are respectively connected to the telescopic guide vanes (1002) and the ventilation pad (700). Two ends of the first spring (1005) are respectively connected to the wedge-shaped guide vanes (1001) and the telescopic guide vanes (1002). The extrusion rod (1006) is connected to the inner wall of the wedge-shaped guide vanes (1001) and penetrates through the telescopic guide vanes (1002). The length of the first arc-shaped telescopic rod (1003) is greater than that of the second arc-shaped telescopic rod (1004). The telescopic lengths of the first arc-shaped telescopic rod (1003) and the second arc-shaped telescopic rod (1004) on the side along the swirl direction of the protective gas are greater than those on the other side. The sides of the wedge-shaped guide vanes (1001) and the telescopic guide vanes (1002) close to the center of the housing (100) are arc-shaped inclined planes.

3. The special welding ventilation protection device for a new type of cavity pipeline according to claim 2, characterized in that: On one side of the ventilation pad (700) close to the swirl passage (103), a number of groups of annularly and evenly distributed ventilation holes (701) are provided. A gas blocking piece (702) is arranged at the ventilation holes (701). On the side of the ventilation pad (700) close to the center of the circle, a sliding plate (703) is provided. On the side of the gas blocking piece (702) close to the outer ring of the ventilation pad (700), a wedge-shaped pressing plate (702-1) is connected. The wedge-shaped pressing plate (702-1) is connected with a second spring (702-2); A sliding rod (104) is also provided on the housing (100); The sliding plate (703) is slidably connected with the sliding rod (104), and the number of groups of the ventilation holes (701) is the same as that of the wedge-shaped guide vanes (1001).

4. A novel cavity-type pipeline special welding ventilation protection device according to claim 1 or 3, characterized in that: On the top of the ventilation pad (700), a number of groups of annularly and evenly distributed air bags (704) are provided. On the bottom of the sealing piece (600), a placement groove (601) corresponding to the air bags (704) is provided. The axial length of the placement groove (601) is shorter than the axial length of the air bags (704) in the fully inflated state.

5. A novel cavity-type pipeline special welding ventilation protection device according to claim 4, characterized in that: On the ventilation pad (700), a gas blocking plate (705) located at the bottom of the air bags (704), a connecting ring (706) connected to the gas blocking plate (705), and a third spring (707) respectively connected to the gas blocking plate (705) and the connecting ring (706) are also provided; On the side of the gas blocking plate (705) close to the housing (100), a wedge-shaped angle (705-1) is provided; On the sealing piece (600), an unlocking groove (602) longitudinally corresponding to the wedge-shaped angle (705-1) is also provided; The gas blocking plate (705) is slidably connected with the connecting ring (706). When the ventilation pad (700) moves to one end of the sealing piece (600), the gas blocking plate (705) is squeezed by the unlocking groove (602) to make the air bags (704) in a ventilable state.

6. A novel cavity-type pipeline special welding ventilation protection device according to claim 1 or 3, characterized in that: On the housing (100), a hinge plate (105), a sealing plug (106) connected to the hinge plate (105), and a C-shaped sleeve (107) slidably connected to the outer wall of the housing (100) are also provided; On the outer wall of the sealing plug (106), a C-shaped column (106-1) is provided; The cavity air discharge ports (102) are longitudinally and evenly arranged in three groups. The aperture of the sealing plug (106) is the same as that of the cavity air discharge ports (102). When the sealing plug (106) closes at the cavity air discharge ports (102), the C-shaped sleeve (107) is coaxial with the C-shaped column (106-1).

7. A novel cavity-type pipeline special welding ventilation protection device according to claim 3, characterized in that: On the housing (100), a number of groups of constant pressure holes (108) communicated with the inner cavity of the housing (100) are also provided. On the ventilation pad (700), through holes (708) with the same aperture as the constant pressure holes (108) are also provided. The through holes (708) are communicated with the ventilation holes (701). An air flow valve (1100) is arranged at the end of the air outlet outer tube (300).

8. A novel cavity-type pipeline special welding ventilation protection device according to claim 1, characterized in that: A cooler (1200) penetrated by the intake inner pipe (200) is arranged on one side of the flowmeter (800).

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