A special welding ventilation protection device for cavity pipes

Abstract

The present invention relates to the field of welding protection technology, and specifically to a special welding ventilation protection device for cavity-type pipelines, comprising a shell, an inner air inlet pipe, an outer air outlet pipe, a pressure regulating valve, a reducer, a sealing plate, a ventilation pad, a flow meter, a pressure gauge, a swirl component, an air flow valve and a cooler; the present invention integrates the inner air inlet pipe and the outer air outlet pipe to reduce the time and cost of specially manufacturing the air outlet tooling, releases the protective gas along the bottom of the device, and makes the protective gas gradually squeeze the air in the cavity upward along the bottom in a swirl state, so that the air in the cavity enters the device along the air outlet port in the cavity, and then is discharged to the outside of the device along the outer air outlet pipe, thereby reducing the occurrence of incomplete air discharge, and through the ventilation pad and the sealing plate, the influence of the air pressure on the sealing plate is reduced when the protective gas fills the pipeline cavity, and the sealing effect is increased to prevent the penetration of gas outside the pipeline cavity.

Description

Technical Field

[0001] The present invention relates to the technical field of welding protection, in particular to a special welding ventilation protection device for cavity-type pipelines. Background Art

[0002] In the pipeline welding process, ventilation protection devices play a vital role. When welding the pipeline, shielding gas is introduced into the pipeline to form an inert gas atmosphere in the welding area and isolate active gases such as oxygen and nitrogen in the air. This can effectively prevent the weld from being oxidized and nitrided at high temperatures, avoid welding defects such as pores and inclusions, and thus ensure the quality and performance of the weld. Cavity pipes are widely used in aerospace, precision instruments, chemical reaction equipment and other fields. Their structures usually have complex features such as multi-stage branches, special-shaped cross-sections, micro-channels or scattering holes. For example, in fuel delivery systems, cooling lines or microreactors, the pipeline may contain special-shaped holes, scattering holes, pinholes, multi-stage structures, etc. At present, conventional pipeline welding ventilation protection mostly uses a simple air pipe connected to both ends of the pipeline, and the air is discharged by gas pressure, or the pipeline is first vacuumed and then the shielding gas is released for ventilation, and the shielding gas is continuously introduced for protection during the welding process.

[0003] However, when performing ventilation protection on cavity-type pipelines, due to the complex conditions of special-shaped holes, scattering holes, pinholes, and multi-level structures at the outlet ends, it is impossible to introduce protective gas through conventional air pipe connections. When performing ventilation protection on this situation, due to the complexity of the outlet pipeline, the air is often not completely discharged, resulting in a certain amount of air remaining in the welding area, or because the air pressure in the cavity needs to be maintained after the air is discharged, the sealing effect is affected, and air infiltration outside the cavity occurs, affecting the welding quality. In the existing technology, when performing ventilation protection on complex cavity pipeline structures, it is necessary to specially manufacture outlet tooling that is suitable for different complex structures for different outlet ends. However, since the outlet ends of cavity-type pipelines often have small outlet apertures and dispersed distribution, not only is the outlet efficiency low and the ventilation process cumbersome, it is difficult to quickly and effectively form welding protective gas coverage, and it requires additional costs and complex processes.

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

[0005] The purpose of the present invention is to provide a special welding ventilation protection device for cavity-type pipes to solve the problems of incomplete air discharge during welding ventilation protection of complex cavity-type pipes, and the problem that the sealing effect is affected when the air pressure in the pipe is ensured, resulting in air infiltration outside the pipe cavity, affecting the pipe welding efficiency and welding quality; by integrating the air inlet inner pipe and the air outlet outer pipe, the time and cost of specially manufacturing the air outlet tooling are reduced, the protective gas is released along the bottom of the device, and the protective gas is squeezed gradually upward along the bottom of the cavity in a swirl state, so that the air in the cavity enters the device along the air outlet port in the cavity, and is then discharged to the outside of the device along the air outlet outer pipe, reducing the occurrence of incomplete air discharge, and through the ventilation pad and the sealing plate, the influence of the air pressure on the sealing plate is reduced when the protective gas fills the inside of the pipe cavity, and the sealing effect is increased to prevent the infiltration of gas outside the pipe cavity.

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

[0007] A special welding ventilation protection device for cavity-type pipelines, comprising a shell, an inner air inlet pipe, an outer air outlet pipe, a pressure regulating valve, a reducer, a sealing sheet, a ventilation pad, a flow meter, a pressure gauge and a swirl assembly; the inner air inlet pipe and the outer air outlet pipe are connected by a reducer; two groups of pressure regulating valves are provided, which are respectively connected to the inner air inlet pipe and the outer air outlet pipe; the shell is provided with a protective gas ventilation cavity, an air discharge port in the cavity, and a swirl flow path connected to the protective gas ventilation cavity; the protective gas ventilation cavity is connected to the inner air inlet pipe, and the air discharge port in the cavity is connected to the outer air outlet pipe, and the protective gas is discharged from the inner air inlet pipe to the protective gas ventilation cavity and enters the pipeline cavity in the form of a swirl flow through the swirl flow path.

[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 cavity-type pipelines, due to the many complex features in its structure, it is more difficult to discharge the gas during protective gas protection, and it is easy to cause the complete discharge of air. By discharging the argon gas with higher density into the pipeline cavity in a vortex along the bottom of the device, the protective gas is separated from the air in the pipeline cavity by centrifugation, and a stable "air curtain" is formed under the orderly vortex, which reduces the mixing of the protective gas and the air in the pipeline cavity, and the air in the cavity is squeezed by the protective gas into the device along the cavity air outlet above the device and discharged to the outside along the air outlet outer pipe, thereby reducing the occurrence of air residue.

[0009] Preferably, the swirl assembly includes a wedge-shaped guide plate, a telescopic guide plate, a first arc-shaped telescopic rod, a second arc-shaped telescopic rod, a first spring, and an extrusion rod. The wedge-shaped guide plates are provided in several groups and are evenly arranged in a ring shape on one side of the ventilation pad close to the swirl passage. The wedge-shaped guide plates are slidingly connected to the telescopic guide plates. The two ends of the first arc-shaped telescopic rod are respectively connected to the wedge-shaped guide plates and the ventilation pad, and the two ends of the second arc-shaped telescopic rod are respectively connected to the telescopic guide plates and the ventilation pad. The two ends of the first spring are respectively connected to the wedge-shaped guide plates and the telescopic guide plates. The extrusion rod is connected to the inner wall of the wedge-shaped guide plate and is passed through the telescopic guide plate. The length of the first arc-shaped telescopic rod is greater than that of the second arc-shaped telescopic rod. The telescopic length of the first arc-shaped telescopic rod and the second arc-shaped telescopic rod on one side of the protective gas swirl direction is greater than that of the first arc-shaped telescopic rod and the second arc-shaped telescopic rod on the other side. The wedge-shaped guide plates and the telescopic guide plates are arc-shaped inclined surfaces close to the center of the shell.

[0010] In the above scheme, the protective air argon is introduced into the device along the air inlet inner tube, and enters the pipeline cavity in a swirling shape after passing through the swirl passage. At this time, the ventilation pad and the swirl assembly are located outside the swirl passage, and the protective air will flow along the arc-shaped inclined surfaces of the wedge-shaped guide vanes and the telescopic guide vanes, and squeeze the wedge-shaped guide vanes and the telescopic guide vanes, so that the wedge-shaped guide vanes and the telescopic guide vanes gradually form an annular guide plate obliquely upward from the center of the shell to the outside by stretching the first arc-shaped telescopic rod and the second arc-shaped telescopic rod, so that the protective gas flows above the wedge-shaped guide vanes and the telescopic guide vanes, intensifying the swirl state of the protective gas, and making the protective gas flow in an upward state toward the air inlet end of the pipeline. By increasing the swirl state of the protective gas and increasing the centrifugal force of the protective gas in the swirl state, it helps to separate the protective gas from the air in the cavity, and produce a stable "air curtain", reducing the mixing of the protective gas with the air in the pipeline cavity.

[0011] Preferably, the ventilation pad is provided with several groups of annular evenly distributed ventilation holes on one side close to the swirl flow passage, an air blocking plate is provided at the ventilation holes, a sliding plate is provided on the side of the ventilation pad close to the center of the circle, and a wedge-shaped extrusion plate is connected to the side of the air blocking plate close to the outer circle of the ventilation pad, and the wedge-shaped extrusion plate is connected to a second spring; a sliding rod is also provided on the shell; the sliding plate is slidably connected to the sliding rod, and the ventilation holes are provided in the same number of groups as the wedge-shaped guide plate.

[0012] In the above scheme, the protective air is continuously discharged into the cavity along the protective gas ventilation cavity and through the swirl path. The protective gas will accumulate under the ventilation pad away from the air inlet end of the pipeline, so that the air pressure under the ventilation pad gradually increases. At this time, under the influence of the air pressure, the ventilation pad will slide along the sliding rod through the sliding plate toward one end of the sealing plate, thereby expanding the volume under the ventilation pad and balancing the air pressure under the ventilation pad. At the same time, the ventilation pad will squeeze the air above it into the inner cavity of the shell along the air outlet in the cavity, and be discharged to the outside through the outer air outlet pipe.

[0013] Preferably, a plurality of groups of airbags evenly distributed in an annular shape are provided on the top of the ventilation cushion, and placement grooves corresponding to the airbags are provided on the bottom of the sealing sheet, and the axial length of the placement grooves is shorter than the axial length of the airbags in a filled state.

[0014] In the above scheme, the ventilation pad will eventually 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 airbag will enter the placement groove. As the airbag is gradually filled, it will generate pressure on both sides of the sealing piece through the placement groove. The sealing piece increases the sealing effect under the action of pressure. At this time, the sealing piece is in close contact with the air pad, which reduces the axial pressure on the sealing piece along the shell, and increases the pressure on the inner wall of the pipe through its own elasticity, thereby reducing the influence of air pressure on the sealing effect and causing air leakage. At the same time, the ventilation pad remains connected to the sealing piece through the airbag.

[0015] Preferably, the ventilation cushion is also provided with an air blocking plate located at the bottom of the airbag, a connecting ring connected to the air blocking plate, and a third spring respectively connected to the air blocking plate and the connecting ring; a wedge-shaped angle is provided on the side of the air blocking plate close to the shell; an unlocking groove corresponding to the longitudinal direction of the wedge-shaped angle is also provided on the sealing sheet; the air blocking plate is slidably connected to the connecting ring, and when the ventilation cushion moves to one end of the sealing sheet, the air blocking plate is squeezed by the unlocking groove to make the airbag become ventilated.

[0016] In the above scheme, when the ventilation pad moves upward to the bottom of the sealing plate, the wedge angle will be blocked under the action of the unlocking groove, causing it to move toward the shell, so that the bottom of the airbag can be ventilated. At this time, an airbag with an axial length greater than the axial length of the placement groove in the filled state can be used, so that radial pressure is applied to the sealing plate through the placement groove when the airbag is filled, thereby ensuring the sealing effect of the sealing plate.

[0017] Preferably, the shell is also provided with a hinged plate, a sealing plug connected to the hinged plate, and a C-shaped sleeve slidably connected to the outer wall of the shell; a C-shaped column is provided on the outer wall of the sealing plug; three groups of air outlets in the cavity are evenly arranged longitudinally, the aperture of the sealing plug is the same as the aperture of the air outlet in the cavity, and the C-shaped sleeve is coaxial with the C-shaped column when the sealing plug is closed at the air outlet in the cavity.

[0018] In the above scheme, when the ventilation pad moves upward to the bottom of the sealing plate, the sealing plate 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 is transmitted 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 outlet of the cavity, and the sealing plug blocks the air outlet at the bottom of the cavity, so that the protective air is reduced from mixing with the air in the cavity.

[0019] Preferably, the shell is also provided with several groups of constant pressure holes connected to the inner cavity of the shell, the ventilation pad is also provided with through holes with the same aperture as the constant pressure holes, the through holes are connected to the ventilation holes, and an air flow valve is provided at the end of the outer air outlet pipe.

[0020] In the above scheme, when the ventilation pad moves upward to the bottom of the sealing plate, the protective gas is continuously introduced. The remaining air in the cavity is squeezed by the protective gas along the vent hole, and flows through the through hole and the constant pressure hole, and is discharged to the outside through the outer gas outlet pipe. After a period of continuous introduction of protective gas, the air in the cavity is reduced to the minimum value, and then the air flow valve is closed to control the protective gas pressure in the cavity to be constant, making the welding process more stable.

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

[0022] In the above scheme, when the shielding gas is introduced, the shielding gas is cooled in advance through the cooler, so that the shielding gas further increases its own density when the temperature drops, making the centrifugal separation from the air in the cavity in the swirl state more obvious, and reducing its own molecular activity, thereby reducing mixing with the air. During welding, the shielding gas is cooled to reduce the high temperature generated during welding and the impact on welding stability.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The present invention proposes a special welding ventilation protection device for cavity-type pipes, which integrates the air inlet inner pipe and the air outlet outer pipe. By inputting argon gas, which has a higher density than air, and passing the shielding gas through the bottom of the device through the pressure regulating valve to pressurize and the cooler to cool it down, it enters the pipe cavity. At this time, the shielding air will have a higher density than the inner cavity gas, and enter the pipe cavity through the swirl passage, forming a swirl inside the pipe cavity. Under the centrifugal effect, it is separated from the air in the cavity and forms a stable "air curtain", which reduces the mixing of the shielding gas and the air in the cavity. A ventilation pad is set to block the upper air in the cavity from the shielding gas, further preventing the shielding gas from mixing with the air in the cavity. After the shielding gas is continuously introduced, the air pressure at the bottom of the ventilation pad gradually increases and squeezes the ventilation pad to slide toward the sealing plate, squeezing the air in the cavity above the ventilation pad along the air outlet in the cavity to the inner cavity of the shell, and discharged to the outside through the outer air outlet pipe. Therefore, there is no need to specially manufacture air outlet tooling adapted to different complex structures to continue to discharge the air in the cavity, reducing the phenomenon of incomplete air discharge caused by complex conditions in the pipeline in the cavity, thereby improving the welding quality.

[0025] 2. The present invention proposes a special welding ventilation protection device for cavity-type pipes. The ventilation pad moves toward the sealing plate under the action of the protective gas pressure and is tightly attached to the sealing plate. At this time, the sealing plate will maintain the air pressure in the cavity while blocking the air pressure it receives along the axial direction of the shell through the ventilation pad. At the same time, the air blocking plate is displaced under the action of the unlocking groove on the sealing plate, so that the airbag becomes ventilated. The airbag is filled under the action of the protective gas pressure under the ventilation pad, thereby applying radial pressure to the sealing plate through the placement groove, increasing the pressure of the sealing plate on the inner wall of the pipe, thereby further improving the sealing effect and preventing the sealing plate from being affected by the air pressure and causing air infiltration, thereby affecting the welding quality.

[0026] 3. The present invention proposes a special welding ventilation protection device for cavity-type pipelines. By setting a swirl component, when the shielding gas is introduced into the cavity through the air inlet inner tube, it will flow out in a swirl shape along the swirl flow path at the bottom of the shell. At this time, the shielding gas will push the swirl component to slide downward under the action of air pressure, thereby playing the role of a guide plate, intensifying the swirl state of the shielding gas, and guiding the shielding gas to rise in the direction of the sealing plate. When the ventilation pad is affected by the air pressure and moves toward the sealing plate, the swirl component gradually closes and approaches the ventilation pad. The wedge shape of the swirl component promotes the shielding gas to stratify with the air in the cavity in the swirl state, further reducing the mixing of the shielding gas and the air in the cavity. When the ventilation pad is squeezed close to the sealing plate, the shielding gas pressure continues to increase to squeeze the swirl component, open the ventilation hole of the ventilation pad, continue to discharge the air in the cavity, and cooperate with the air flow valve after the air in the cavity is reduced to the lowest level to keep the air pressure in the cavity stable, thereby improving the welding quality. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0028] Figure 2 This is a schematic diagram of the shell cross-section structure of the special welding ventilation protection device for cavity-type pipelines;

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

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

[0031] Figure 5 Special welding ventilation protection device for cavity pipes Figure 4 A in the middle is an enlarged schematic diagram;

[0032] Figure 6 Special welding ventilation protection device for cavity pipes Figure 4The enlarged schematic diagram of point B in the middle;

[0033] Figure 7 This is a schematic diagram of the ventilation completion state of the special welding ventilation protection device for cavity-type pipelines;

[0034] Figure 8 This is a schematic diagram of the connection between the C-shaped sleeve and the sealing plug of the special welding ventilation protection device for cavity-type pipelines;

[0035] Figure 9 This is a schematic diagram of the expanded structure of the swirl component of the special welding ventilation protection device for cavity-type pipes;

[0036] Figure 10 This is a schematic diagram of the cross-sectional structure of the swirl component of the special welding ventilation protection device for cavity-type pipelines;

[0037] Figure 11 This is a schematic diagram of the use process of the special welding ventilation protection device for cavity-type pipelines;

[0038] Figure 12 Special welding ventilation protection device for cavity pipes Figure 9 Enlarged schematic diagram at point C in the middle.

[0039] In the figure: 100, housing; 101, protective gas ventilation cavity; 102, cavity air outlet; 103, swirl flow path; 200, air inlet inner tube; 300, air outlet outer tube; 400, pressure regulating valve; 500, reducer; 600, sealing plate; 601, placement groove; 602, unlocking groove; 700, ventilation pad; 701, ventilation hole; 702, air blocking plate; 702-1, wedge-shaped extrusion plate; 702-2, second spring; 703, sliding plate; 704, air bag; 705, air blocking plate; 705-1, wedge angle; 7 06, connecting ring; 707, third spring; 708, through hole; 800, flow meter; 900, barometer; 1000, swirl assembly; 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, hinged plate; 106, sealing plug; 106-1, C-shaped column; 107, C-shaped sleeve; 108, constant pressure hole; 1100, air flow valve; 1200, cooler. DETAILED DESCRIPTION

[0040] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0041] In the following description, many specific details are set forth to facilitate a full 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 may obtain other implementation methods without violating the connotation of the present invention and without expending creative work. Therefore, the present invention is not limited to the specific embodiments disclosed below.

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

[0043] A special welding ventilation protection device for cavity-type pipelines, comprising a shell 100, an air inlet inner tube 200, an air outlet outer tube 300, a pressure regulating valve 400, a reducer 500, a sealing sheet 600, a ventilation pad 700, a flow meter 800, a barometer 900 and a swirl assembly 1000; the air inlet inner tube 200 is connected to the air outlet outer tube 300 through a reducer 500; the pressure regulating valve 400 is provided with two groups, which are respectively connected to the air inlet inner tube 200 and the air outlet outer tube 300; the shell 100 is provided with a protective gas ventilation cavity 101, an air outlet 102 in the cavity, and a swirl flow passage 103 connected to the protective gas ventilation cavity 101; the protective gas ventilation cavity 101 is connected to the air inlet inner tube 200 The air outlet 102 in the cavity is connected to the outer air outlet tube 300, and the protective gas is discharged from the air inlet inner tube 200 to the protective gas ventilation cavity 101 and enters the pipeline cavity in a swirling flow through the swirl flow path 103, so that the air in the cavity enters the outer air outlet tube 300 along the air outlet 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 plate 600, when the protective gas fills the inside of the pipeline cavity, the influence of the air pressure on the sealing plate 600 is reduced, and the sealing effect is enhanced to prevent the penetration of gas outside the pipeline cavity. It should be noted that in order to make the protective gas easier to centrifugally separate from the gas in the cavity in a swirling state, argon with a density greater than air can be used as the protective gas here.

[0044] As an embodiment of the present invention, refer to Figure 2 、 Figure 7 、 Figure 9 、 Figure 10 、 Figure 11 and Figure 12The swirl assembly 1000 includes a wedge-shaped guide plate 1001, a telescopic guide plate 1002, a first arc-shaped telescopic rod 1003, a second arc-shaped telescopic rod 1004, a first spring 1005, and an extrusion rod 1006. The wedge-shaped guide plate 1001 is provided with a plurality of groups of ring-shaped uniformly distributed on the side of the ventilation pad 700 close to the swirl passage 103, and is slidably connected to the telescopic guide plate 1002. The two ends of the first arc-shaped telescopic rod 1003 are respectively connected to the wedge-shaped guide plate 1001 and The ventilation pad 700 is connected, the two ends of the second arc-shaped telescopic rod 1004 are respectively connected to the telescopic guide piece 1002 and the ventilation pad 700, the two ends of the first spring 1005 are respectively connected to the wedge-shaped guide piece 1001 and the telescopic guide piece 1002, the extrusion rod 1006 is connected to the inner wall of the wedge-shaped guide piece 1001 and is penetrated by the telescopic guide piece 1002, the length of the first arc-shaped telescopic rod 1003 is greater than that of the second arc-shaped telescopic rod 1004, and the first spring 1005 is connected to the wedge-shaped guide piece 1001 and the telescopic guide piece 1002. The telescopic length of the arc-shaped telescopic rod 1003 and the second arc-shaped telescopic rod 1004 is greater than the other side, and the wedge-shaped guide plate 1001 and the telescopic guide plate 1002 are arc-shaped inclined surfaces close to the center of the shell 100; the protective gas enters the device along the air inlet inner tube 200, and enters the pipeline cavity in a swirling shape after passing through the swirl passage 103. The ventilation pad 700 and the swirl assembly 1000 are located outside the swirl passage 103. The protective gas flows along the arc-shaped inclined surfaces of the wedge-shaped guide plate 1001 and the telescopic guide plate 1002 and squeezes the two, so that the wedge-shaped guide plate 1001 and the telescopic guide plate 1002 gradually form an annular guide plate obliquely upward from the center of the shell 100 to the outside by stretching the first arc-shaped telescopic rod 1003 and the second arc-shaped telescopic rod 1004, intensifying the swirl state of the protective gas and flowing in an upward state toward the air inlet end of the pipeline, increasing the centrifugal force of the swirl of the protective gas, and helping to separate the protective gas from the air in the cavity, forming a stable "air curtain" to reduce mixing.

[0045] As an embodiment of the present invention, refer to Figure 4 and Figure 11 The ventilation pad 700 is provided with a plurality of annular evenly distributed ventilation holes 701 on the side close to the swirl flow passage 103, and an air blocking sheet 702 is provided at the ventilation hole 701. A sliding plate 703 is provided on the side close to the center of the ventilation pad 700. The air blocking sheet 702 is connected to a wedge-shaped extrusion plate 702-1 on the side close to the outer ring of the ventilation pad 700, and the wedge-shaped extrusion plate 702-1 is connected to the second spring 702-2. A sliding rod 104 is also provided on the housing 100. The sliding plate 703 is connected to the sliding plate 703. The movable rod 104 is slidably connected, and the vent holes 701 are arranged in the same number as the wedge-shaped guide plate 1001; when the protective gas is continuously discharged into the cavity, the air pressure below the vent pad 700 increases, and the vent pad 700 slides along the sliding rod 104 toward one end of the sealing plate 600 through the sliding plate 703 under the action of the air pressure, expanding the volume below the vent pad 700 to balance the air pressure, and at the same time squeezing the air above into the inner cavity of the shell 100 along the air outlet 102 in the cavity and discharged from the outer air outlet pipe 300.

[0046] As an embodiment of the present invention, refer to Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 and Figure 8 , a plurality of groups of airbags 704 are evenly distributed in an annular shape are provided on the top of the ventilation pad 700, and a placement groove 601 corresponding to the airbag 704 is provided at the bottom of the sealing sheet 600, and the axial length of the placement groove 601 is shorter than the axial length of the airbag 704 in the filled state; when the ventilation pad 700 moves to the sealing sheet 600, the airbag 704 enters the placement groove 601, and the filled airbag 704 generates pressure on both sides of the sealing sheet 600 through the placement groove 601. Under the action of pressure, the sealing sheet 600 increases the sealing effect and reduces the leakage caused by the influence of air pressure. The ventilation pad 700 is connected to the sealing sheet 600 through the airbag 704. It should be noted that the position of the airbag 704 does not coincide with the position of the vent hole 701, and the protective gas can enter the inner cavity of the ventilation pad 700 along the vent hole 701 and enter the airbag 704.

[0047] As an embodiment of the present invention, refer to Figure 6 and Figure 7 The ventilation cushion 700 is also provided with an air blocking plate 705 located at the bottom of the airbag 704, a connecting ring 706 connected to the air blocking plate 705, and a third spring 707 connected to the air blocking plate 705 and the connecting ring 706 respectively; the air blocking plate 705 is provided with a wedge angle 705-1 on the side close to the shell 100; the sealing sheet 600 is also provided with an unlocking groove 602 corresponding to the longitudinal direction of the wedge angle 705-1; the air blocking plate 705 is slidably connected to the connecting ring 706, and the ventilation cushion 700 is provided with an air blocking plate 705 located at the bottom of the airbag 704, a connecting ring 706 connected to the air blocking plate 705, and a third spring 707 connected to the air blocking plate 705 and the connecting ring 706 respectively. 00 moves to one end of the sealing piece 600, the air blocking plate 705 is squeezed by the unlocking groove 602, so that the airbag 704 becomes ventilated; when the ventilation cushion 700 moves upward to the bottom of the sealing piece 600, the unlocking groove 602 blocks the wedge angle 705-1 and makes it move toward the shell 100, and the bottom of the airbag 704 is ventilated. The airbag 704, whose axial length in the filled state is 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, refer to Figure 7 and Figure 8The housing 100 is also provided with 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; a C-shaped column 106-1 is provided on the outer wall of the sealing plug 106; three groups of air outlets 102 in the cavity are evenly arranged in the longitudinal direction, and the aperture of the sealing plug 106 is the same as that of the air outlet 102 in the cavity. When the sealing plug 106 is closed at the air outlet 102 in the cavity, 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 sheet 600, the C-shaped sleeve 107 moves to the bottom of the sealing plug 106 to squeeze the C-shaped column 106-1, and the sealing plug 106 is transmitted through the hinged plate 105 until the C-shaped column 106-1 is coaxial with the C-shaped sleeve 107. The sealing plug 106 is at the air outlet 102 in the cavity to block the air outlet 102 in the bottom cavity, thereby reducing the mixing of protective air and the air in the cavity.

[0049] As an embodiment of the present invention, refer to Figure 1 、 Figure 2 and Figure 7 The shell 100 is also provided with several groups of constant pressure holes 108 that are connected to the inner cavity of the shell 100. The ventilation pad 700 is also provided with a through hole 708 with the same aperture as the constant pressure hole 108. The through hole 708 is connected to the ventilation hole 701, and an air flow valve 1100 is provided at the end of the outer air outlet tube 300; when the ventilation pad 700 moves to the bottom of the sealing plate 600, the remaining air in the cavity flows along the ventilation hole 701, the through hole 708 and the constant pressure hole 108 through the outer air outlet tube 300 and is discharged. After the protective gas is continuously introduced to reduce the air in the cavity to the minimum value, the air flow valve 1100 is closed to control the protective gas pressure in the cavity to be constant, thereby stabilizing the welding process.

[0050] As an embodiment of the present invention, refer to Figure 2 、 Figure 6 and Figure 7 A cooler 1200 connected to the air inlet inner pipe 200 is provided on one side of the flow meter 800; when the shielding gas is introduced, the shielding gas is cooled by the cooler 1200 to increase its density, thereby improving the centrifugal separation effect with the air in the cavity, reducing the molecular activity and the degree of mixing with the air, and reducing the impact of excessive temperature on welding stability.

[0051] Working principle: The protective gas is input through the starting device, and the protective gas enters the interior of the pipeline cavity through the air inlet inner tube 200, and is discharged along the protective gas ventilation cavity 101 at the bottom of the shell 100. After flowing through the swirl path 103, it is in the pipeline cavity in a swirl shape. The protective gas is squeezed open by the air pressure swirl component 1000, and the swirl state of the protective gas is intensified under the guidance effect after the swirl component 1000 is opened. After the protective gas is continuously input, the ventilation pad 700 is squeezed toward the sealing plate 600 by the air pressure, and the ventilation pad 700 gradually squeezes the air in the pipeline cavity upwards, and the air is discharged along the swirl path 103. The air outlet 102 in the cavity enters the inner cavity of the shell 100 and is discharged to the outside through the outer air outlet pipe 300. During the process of the protective gas entering, the air pressure under the ventilation pad 700 increases, pushing the ventilation pad 700 to slide upward, so that it is in close contact with the sealing piece 600. At this time, the air blocking plate 705 is squeezed by the unlocking groove 602, so that the air bag 704 becomes ventilated. The air bag 704 is filled under the action of air pressure and pressure is applied to the sealing piece 600 through the placement groove 601 to enhance the sealing effect. Finally, the protective gas fills the pipeline cavity, the air in the cavity is discharged, and the ventilation protection is completed, thereby improving the welding quality.

[0052] Specifically: First, the pipeline aperture of the pipeline cavity is sealed by existing technology, and the shell 100 and its connecting part are passed into the pipeline cavity along the pipeline mouth until the sealing piece 600 is located at the bottom of the pipeline. When the protective gas is introduced, the protective gas is passed into the inner cavity of the shell 100 through the air inlet inner tube 200, and flows into the interior of the pipeline cavity through the protective gas ventilation cavity 101 on the shell 100. After flowing through the swirl path 103, it enters the pipeline cavity in a swirl shape. At this time, the protective gas enters the interior of the pipeline cavity under the state of pressurization by the pressure regulating valve 400 and cooling by the cooler 1200. The density of the protective gas after being pressurized and cooled increases. When it enters the interior of the pipeline cavity in a swirl, the protective gas with higher density is centrifuged under the action of the swirl. The protective air is stratified with the air in the pipeline cavity through centrifugation, thereby reducing mixing with the air in the pipeline cavity. At the same time, under the action of air pressure, the protective air initially entering the pipeline cavity will flow along the arc-shaped inclined surfaces of the wedge-shaped guide plate 1001 and the telescopic guide plate 1002, and squeeze the wedge-shaped guide plate 1001 and the telescopic guide plate 1002, so that the wedge-shaped guide plate 1001 and the telescopic guide plate 1002 gradually form an annular guide plate obliquely upward from the center of the shell 100 to the outside by stretching the first arc-shaped telescopic rod 1003 and the second arc-shaped telescopic rod 1004, so that the protective gas flows above the wedge-shaped guide plate 1001 and the telescopic guide plate 1002, intensifying the swirl state of the protective gas, and causing the protective gas to flow in an upward state toward the air inlet end of the pipeline.

[0053] Continuously introduce the protective gas, which will gradually fill the pipe cavity space below the ventilation pad 700 along one side of the protective gas ventilation cavity 101. At this time, the air pressure in the area below the ventilation pad 700 gradually increases, causing the ventilation pad 700 to slide axially along the sliding rod 104 through the sliding plate 703, and the wedge-shaped guide plate 1001 and the telescopic guide plate 1002 will re-fit with the ventilation pad 700 under the action of the built-in springs and air pressure of the first arc telescopic rod 1003 and the second arc telescopic rod 1004. At this time, under the action of the wedge-shaped arc surface at the bottom of the wedge-shaped guide plate 1001, the centrifugal separation state of the protective gas that rises in the direction of the sealing plate 600 and the air in the pipe cavity will be promoted, further preventing the protective gas from mixing with the air in the pipe cavity. At this time, the ventilation pad 700 will move toward the sealing plate 600, and drive the C-shaped sleeve 107 to move upward during the movement, and the ventilation pad 700 When it 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 hinged plate 105. At the same time, the C-shaped sleeve 107 will squeeze the C-shaped column 106-1 at the same time until the sealing plug 106 is closed to the air outlet 102 in the cavity. At this time, the C-shaped sleeve 107 continues to move upward under the drive of the ventilation pad 700. The C-shaped sleeve 107 will now be located on one side of the C-shaped column 106-1, thereby limiting the sealing plug 106. Since the outer wall of the shell 100 is an arc surface, when the sealing plug 106 is closed to the air outlet 102 in the cavity, the air outlet 102 in the cavity will not be absolutely sealed. At this time, under the action of the protective gas pressure, a part of the protective gas will enter the interior of the shell 100 along the air outlet 102 in the cavity, and under the action of the protective gas, the air in the pipeline cavity is squeezed toward the air outlet outer pipe 300, thereby promoting the discharge of air in the cavity.

[0054] When the pipe cavity is filled with protective air, the ventilation pad 700 continues to slide toward the sealing piece 600 until the ventilation pad 700 is in close contact with the sealing piece 600. When the ventilation pad 700 approaches the sealing piece 600, the through hole 708 on the ventilation pad 700 will gradually coincide with the constant pressure hole 108. At this time, the process of continuously introducing protective gas will cause the air pressure below the ventilation pad 700 away from the sealing piece 600 to continue to increase. When the air pressure is greater than the elastic force of the first spring 1005, the wedge-shaped guide piece 1001 will be squeezed to contract toward the telescopic guide piece 1002. At this time, the wedge-shaped guide piece 1001 gradually coincides with the telescopic guide piece 1002, and the wedge-shaped guide piece 1001 passes through the telescopic guide piece 1002 through the squeezing rod 1006. , and squeezes toward the wedge-shaped extrusion plate 702-1, driving the air blocking plate 702 to move toward the side of the second spring 702-2. At this time, gas can flow into the vent hole 701, and the gas under the vent pad 700 continues to flow along the vent hole 701, through the vent pad 700, and flows along the through hole 708 to the inner cavity of the shell 100. Under the swirl state below the vent pad 700, the air in the pipeline cavity will more easily enter the vent hole 701 and be discharged to the outside of the cavity through the outer air outlet pipe 300. The protective gas is continuously introduced to discharge the air in the pipeline cavity to the lowest level, and then the air flow valve 1100 can be closed to reduce the circulation of the protective gas, and the pressure regulating valve 400 can be used to adjust the pressure in the pipeline cavity to keep it stable, thereby improving the welding quality.

[0055] When the vent pad 700 is in close contact with the sealing sheet 600, the air pressure on the sealing sheet 600 will be blocked by the vent pad 700, thereby reducing the impact of the air pressure on the sealing sheet 600 and preventing the pressure from increasing and causing sealing leakage. 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 toward the shell 100, thereby releasing the sealing effect on the bottom of the airbag 704, making the airbag 704 become ventilated. The airbag 704 is filled under the action of air pressure. At this time, the airbag 704 will apply radial pressure to the sealing sheet 600 through the placement groove 601, and the sealing sheet 600 will increase the pressure on the inner wall of the pipe, thereby enhancing the sealing effect.

[0056] The above embodiments are only used to illustrate some examples of the implementation of the technical solution of the present invention and are not intended to limit the implementation methods. The present invention can be understood in more detail with reference to the embodiments. Those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A special welding ventilation protection device for cavity pipes, characterized by: The invention comprises a housing (100), an inner air inlet pipe (200), an outer air outlet 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 inner air inlet pipe (200) and the outer air outlet pipe (300) are connected via the reducing joint (500); the pressure regulating valve (400) is provided with two groups, which are respectively connected to the inner air inlet pipe (200) and the outer air outlet pipe (300). The housing (100) is provided with a protective gas ventilation cavity (101), an air outlet (102) in the cavity, and a swirl flow passage (103) connected to the protective gas ventilation cavity (101); the protective gas ventilation cavity (101) is communicated with the inner air inlet tube (200), and the air outlet (102) in the cavity is communicated with the outer air outlet tube (300); the protective gas is discharged from the inner air inlet tube (200) to the protective gas ventilation cavity (101) and enters the pipe cavity in a swirl flow through the swirl flow passage (103); The swirl assembly (1000) comprises a wedge-shaped guide plate (1001), a telescopic guide plate (1002), a first arc-shaped telescopic rod (1003), a second arc-shaped telescopic rod (1004), a first spring (1005), and an extrusion rod (1006). The wedge-shaped guide plates (1001) are provided in a plurality of groups and are evenly arranged in an annular shape on one side of the ventilation pad (700) close to the swirl passage (103). The wedge-shaped guide plates (1001) are slidably connected to the telescopic guide plates (1002). The two ends of the first arc-shaped telescopic rod (1003) are respectively connected to the wedge-shaped guide plate (1001) and the ventilation pad (700). The two ends of the second arc-shaped telescopic rod (1004) are respectively connected to the telescopic guide plate (1002) and the ventilation pad (700). 00), the two ends of the first spring (1005) are respectively connected to the wedge-shaped guide plate (1001) and the telescopic guide plate (1002), the extrusion rod (1006) is connected to the inner wall of the wedge-shaped guide plate (1001) and is penetrated by the telescopic guide plate (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 length of the first arc-shaped telescopic rod (1003) and the second arc-shaped telescopic rod (1004) on one side along the cyclonic direction of the protective gas is greater than that of the first arc-shaped telescopic rod (1003) and the second arc-shaped telescopic rod (1004) on the other side, and the wedge-shaped guide plate (1001) and the telescopic guide plate (1002) are formed into arc-shaped inclined surfaces on the side close to the center of the shell (100).

2. The special welding ventilation protection device for cavity-type pipelines according to claim 1 is characterized in that: The ventilation pad (700) is provided with a plurality of groups of annular evenly distributed ventilation holes (701) on one side close to the swirl flow passage (103), and an air blocking plate (702) is provided at the ventilation hole (701). The ventilation pad (700) is provided with a sliding plate (703) on the side close to the center of the circle, and the air blocking plate (702) is connected to a wedge-shaped extrusion plate (702-1) on the side close to the outer circle of the ventilation pad (700), and 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 with the same number of groups as the wedge-shaped guide plate (1001).

3. A special welding ventilation protection device for cavity-type pipelines according to claim 1 or 2, characterized in that: The top of the ventilation cushion (700) is provided with a plurality of groups of airbags (704) evenly distributed in an annular shape, and the bottom of the sealing sheet (600) is provided with placement grooves (601) corresponding to the airbags (704), and the axial length of the placement grooves (601) is shorter than the axial length of the airbags (704) in a filled state.

4. The special welding ventilation protection device for cavity-type pipelines according to claim 3 is characterized in that: The ventilation cushion (700) is further provided with an air blocking plate (705) located at the bottom of the air bag (704), a connecting ring (706) connected to the air blocking plate (705), and a third spring (707) respectively connected to the air blocking plate (705) and the connecting ring (706); the air blocking plate (705) is provided with a wedge angle (705-1) on the side close to the shell (100); the sealing sheet (600) is further provided with an unlocking groove (602) longitudinally corresponding to the wedge angle (705-1); the air blocking plate (705) is slidably connected to the connecting ring (706), and when the ventilation cushion (700) moves to one end of the sealing sheet (600), the air blocking plate (705) is squeezed by the unlocking groove (602) so that the air bag (704) becomes ventilated.

5. A special welding ventilation protection device for cavity-type pipelines according to claim 1 or 2, characterized in that: The shell (100) is further provided with 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 shell (100); a C-shaped column (106-1) is provided on the outer wall of the sealing plug (106); three groups of air outlets (102) in the cavity are evenly arranged in the longitudinal direction, the aperture of the sealing plug (106) is the same as the aperture of the air outlet (102) in the cavity, and when the sealing plug (106) is closed at the air outlet (102) in the cavity, the C-shaped sleeve (107) and the C-shaped column (106-1) are coaxial.

6. The special welding ventilation protection device for cavity-type pipes according to claim 2 is characterized in that: The shell (100) is further provided with a plurality of groups of constant pressure holes (108) communicating with the inner cavity of the shell (100), the ventilation pad (700) is further provided with a through hole (708) having the same aperture as the constant pressure hole (108), the through hole (708) is communicated with the ventilation hole (701), and an air flow valve (1100) is provided at the end of the air outlet outer tube (300).

7. The special welding ventilation protection device for cavity-type pipelines according to claim 1 is characterized in that: A cooler (1200) is provided on one side of the flow meter (800) and is passed through the air intake inner pipe (200).

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