A protective welding device for metal hose joint

Abstract

The present invention relates to a protective welding device for a metal hose joint, and belongs to the technical field of welding equipment. The upper part of the closed cavity unit of the device has a welding gun insertion hole, and is equipped with a welding gun telescopic positioning unit; the two ends are respectively equipped with a positioning end cover and an insertion end cover; the positioning end cover fixes a guide core rod, and the outer circle of the guide core rod matches the through diameter of the metal bellows; the guide core rod is equipped with a positioning slider, and the outer section of the positioning slider has a centering recess; the insertion hole of the insertion end cover is equipped with a membrane flap rubber sealing pad, and the membrane flap rubber sealing pad is composed of a group of rubber sheets with fixed outer ends and elastically closed inner ends. The present invention properly solves the difficult problem of gas shielded welding of metal hoses for stove pipes, and can not only efficiently complete the rapid batch welding of metal hoses, but also avoids the disadvantages of poor manual positioning accuracy and uneven welding ends, thereby ensuring the consistency of welding quality.

Description

Technical Field

[0001] The invention relates to a welding device for a small-caliber metal hose, in particular to a protective welding device for a metal hose joint, belonging to the technical field of welding equipment. Background Art

[0002] Small-diameter metal hoses, such as those used in stoves, are required to have comprehensive properties such as flexibility, vibration resistance, pressure resistance, corrosion resistance, and fatigue resistance. They are actually composed of thin-walled stainless steel metal bellows, PVC coating, buckle rings, and connector components. Common connector components include G1 / 2 thread and socket thread structure (see Figure 7 , Fig.10 ) etc. During manufacturing, after the metal bellows is covered with a layer of PVC protective layer, the end of the bellows is subjected to half-wave knocking (i.e. flattening) treatment, and then the pressure ring is buckled, and then it is butt-welded with the joint assembly.

[0003] For a long time, small-diameter metal hoses such as those used for stoves have been welded in an open manner using traditional simple welding positioning tools. The plastic-coated bellows end is inserted into the buckle ring, then aligned with the welding pipe of the joint assembly, the welding gun position is manually adjusted, and the bellows body is rotated to start arc welding. This traditional welding method not only cannot avoid oxidation during the welding process, but also has unstable welding quality and low yield rate.

[0004] Chinese patent documents with announcement numbers CN101486125B, CN103934556A, CN203918190U, CN107088714A, CN108672934A, etc. disclose welding positioning tools for some pipe connectors. However, the above-mentioned prior arts are not designed for gas shielded welding of small-diameter metal hose connectors, and therefore cannot solve the problem of reliable in-situ welding of the metal bellows end and the connector assembly in a gas shielded environment, and the problem of convenient removal after welding.

[0005] To avoid confusion in the meaning of technical terms, the metal bellows in this application refers to a bare tube, without joints, coatings, or clamping rings; the bellows unit does not contain joints but contains coatings and clamping rings; the metal hose refers to the final product including joints. Summary of the invention

[0006] The purpose of the present invention is to provide a metal hose joint protection welding device which can properly solve the problem of reliable in-situ welding of the metal bellows end and the joint assembly in a gas protection environment and can be conveniently transferred.

[0007] In order to achieve the above-mentioned object, the basic technical scheme of the metal hose joint protection welding device of the present invention is: comprising a closed cavity unit with a welding observation port on one side and a welding gun telescopic positioning unit, wherein the upper part of the closed cavity unit has a welding gun insertion hole;

[0008] The two ends of the hollow sealed chamber of the sealed chamber unit are respectively provided with a positioning end cap and an insertion end cap;

[0009] The positioning end cover fixes a guide core rod extending through the closed chamber and extending out of the positioning end cover, and the outer circle of the guide core rod matches the through diameter of the metal bellows;

[0010] The guide core rod is provided with a positioning slide block which forms a horizontal moving pair therewith, and the outer section of the positioning slide block has a centering recess which matches the shape of the head assembly to be welded;

[0011] The central through hole of the insertion end cover is provided with a membrane flap rubber sealing pad, and the membrane flap rubber sealing pad is composed of a group of rubber sheets with fixed outer ends and elastically closed inner ends.

[0012] During welding, pull out the positioning slider to the outermost end of the guide core rod, and place the joint assembly in its centering depression for positioning; then, after the end of the bellows with a buckling ring on the coating layer is exposed to the complete knocking end, pass it through the core rod and the membrane rubber sealing pad together with the joint assembly and push it into the welding position in the closed chamber; then, fill it with protective gas, lower the welding gun to start arc spot welding, and rotate it one circle to complete the welding. After cooling, turn off the protective gas, raise the welding gun, pull out the metal bellows from the closed chamber along the core rod and take out the positioning slider at the same time, remove the metal hose for the stove that has been welded, turn around and repeat the above process if necessary, and the joint protection welding at both ends can be completed.

[0013] The present invention cleverly uses a positioning slider and a guide core rod to organically combine the external centering of the joint assembly with the internal centering of the bellows, so that the two can be accurately positioned, and the membrane petal rubber sealing pad of the closed cavity unit is used to achieve the convenience of both entering the gas protection environment into position and being removed after welding, thereby properly solving the difficult problem of gas shielded welding of metal hoses for stove pipes. Not only can it efficiently complete the batch rapid welding of metal hoses, but it also avoids the disadvantages of poor manual positioning accuracy, uneven welding ends, etc., and ensures the consistency of welding quality.

[0014] A further improvement of the present invention is that the membrane valve rubber sealing gasket is composed of a group of trapezoidal rubber sheets with long sides as outer ends fixed to the central perforated circle of the insertion end cover and short sides as inner ends elastically closed, the adjacent waists of each trapezoidal rubber sheet are mutually matched, and the short sides of each trapezoidal rubber sheet form a positioning slider insertion hole with a closed diameter matching the positioning core rod.

[0015] A further improvement of the present invention is that: the lower side of the guide core rod has an axially extending keyway, and the positioning slider has a dynamic fitting convex key structure embedded in the keyway.

[0016] A further improvement of the present invention is that the upper portion of the outer section of the slider body of the positioning slider is open, and the lower portion has an axial limiting centering recess that matches the shape of the head assembly to be welded.

[0017] The present invention is further improved in that: the upper part of the closed cavity unit is fixed with the help of a strong magnetic block to the welding gun sealing gasket, and the middle part of the welding gun sealing gasket is provided with a welding gun insertion hole.

[0018] A further improvement of the present invention is that: the welding gun telescopic positioning unit is arranged on one side of the closed cavity unit, and contains a welding gun clamp and a telescopic cylinder; the welding gun clamp is installed at the telescopic moving end of the telescopic cylinder, the gun body of the welding gun is fixed in the clamping hole of the welding gun clamp, and the gun head extends into the welding gun insertion hole.

[0019] A further improvement of the present invention is that the front side of the hollow sealed chamber is provided with a welding observation port for inserting an arc light filtering eyepiece. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further explained below in conjunction with the accompanying drawings.

[0021] Figure 1 It is a schematic diagram of the three-dimensional structure of the first embodiment of the present invention.

[0022] Figure 2 for Figure 1 Schematic diagram of the three-dimensional structure of the closed cavity unit in the embodiment.

[0023] Figure 3 for Figure 1 Schematic diagram of the protective gas system structure in the embodiment.

[0024] Figure 4 for Figure 1 Schematic diagram of the three-dimensional structure of the pipe thread positioning unit in the embodiment.

[0025] Figure 5 for Figure 4 Schematic diagram of the partial cross-sectional structure.

[0026] Figure 6 for Figure 1 Schematic diagram of the welding gun telescopic positioning unit structure in the embodiment.

[0027] Figure 7 for Figure 1 Schematic diagram of the three-dimensional structure of the welded pipe threaded metal hose in the embodiment.

[0028] Figure 8 for Figure 1 A schematic diagram of the feeding state structure of an embodiment.

[0029] Fig. 9 for Figure 1 A schematic structural diagram of the positioning welding state of an embodiment.

[0030] Fig.10This is a three-dimensional structure of a welded socket-type threaded metal hose unit according to the second embodiment of the present invention.

[0031] Fig.11 for Fig.10 Schematic diagram of the three-dimensional structure of the socket-type thread positioning unit in the embodiment.

[0032] Fig.12 for Fig.11 Schematic diagram of the partial cross-sectional structure. DETAILED DESCRIPTION

[0033] Embodiment 1

[0034] This embodiment is a protective welding device for a metal hose joint for a stove, and its basic structure is as follows: Figure 1 As shown, it includes a ventilation interface 1, a closed cavity unit 2, a joint assembly positioning unit 3, and a welding gun telescopic positioning unit 5. The metal bellows unit 4 is placed in the joint assembly positioning unit 3 for welding positioning.

[0035] Combination Figure 2 It can be seen that the cylindrical hollow sealed chamber 205 serving as the main body of the sealed chamber unit 2 is supported on vertical brackets 201 at both ends thereof, and has a welding observation port 204 on the front side for inserting an arc filter eyepiece 203, and a welding gun sealing gasket 207 is fixed to the upper part by means of a strong magnetic block 206, and the welding gun sealing gasket 207 has a welding gun insertion hole in the middle. The two ends of the closed chamber 205 are respectively provided with a positioning end cap 202 and an insertion end cap 210 through a sealing gasket 208, wherein the insertion end cap 210 has a central through hole provided with a membrane flap rubber sealing gasket 209, and the membrane flap rubber sealing gasket 209 is composed of a group of trapezoidal rubber sheets with long sides as outer ends fixed around the central through hole and short sides as inner ends elastically closed, the adjacent waists of each trapezoidal rubber sheet are mutually matched, and the short sides of each trapezoidal rubber sheet form a positioning slider insertion hole whose aperture after closing matches the outer diameter of the positioning core rod; in this way, the elastic deformation of each trapezoidal rubber sheet allows the positioning slider to pass through, and once through, since the closed diameter after elastic reset matches the positioning core rod, an ideal closed chamber can be formed, which is convenient for filling with protective gas. The positioning end cap 202 fixes the guide core rod 303 that passes through the closed chamber and extends out of the positioning end cap insertion hole. In addition, the positioning end cap 202 is provided with a ventilation interface 1 for introducing protective gas, and the ventilation interface 1 is composed of Figure 3 The shielding gas system shown provides shielding gas such as argon or nitrogen as needed. The gas source 101 of the system passes through the pressure gauge 102, the pressure regulator 103, the flow meter 104 and the solenoid valve 105 in sequence, and enters the closed cavity unit 2 through the ventilation interface 1 to play a protective role in the welding process.

[0036] The joint assembly positioning unit 3 is as follows Figure 4 and Figure 5As shown, it includes a guide core rod 303, a locking nut 301, and a pipe thread positioning slider 302. The outer circle of the guide core rod 303 matches the diameter of the metal bellows. The left end of the guide core rod 303 has a thread and is fixed to the center of the positioning end cover 202 through the locking nut 301.

[0037] The pipe thread positioning slider 302 is sleeved on the guide core rod 303, forming a horizontal moving pair with the guide core rod 303. The lower side of the guide core rod 303 has an axially extending keyway, and the positioning slider 302 has a dynamic mating convex key structure embedded in the keyway, so the positioning slider 302 can only slide axially and cannot rotate circumferentially. The positioning slider 302 consists of a slider body 3021 and a positioning ring 3022 embedded in the center hole of the slider body to play an axial limiting role. The upper part of the outer section of the slider body 3021 is open, and the lower part has an axial limiting centering recess that matches the shape of the head assembly to be welded, so that the head assembly 401 to be welded can be easily placed therein for centering and limiting, avoiding movement and interference welding during nut welding. After welding is completed, the positioning slider can be pulled out of the closed cavity with the metal bellows to achieve repeated welding operations.

[0038] The welding gun telescopic positioning unit 5 is arranged on one side of the closed chamber unit 2. Figure 6 As shown, it contains an argon arc welding gun 501, a welding gun clamp 502, and a three-axis telescopic cylinder 505 (TCM10×20 model purchased from AirTac Corporation). The gun body of the argon arc welding gun 501 is fixed in the clamping hole of the welding gun clamp 502 by bolts 503, and the gun head extends into the welding gun insertion hole in the middle of the welding gun sealing gasket 207.

[0039] The welding gun clamp 502 is mounted on the telescopic moving end of the three-axis telescopic cylinder 505 by means of bolts 504, and can be moved as required along the welding gun insertion hole of the welding gun sealing pad 207 under the drive of the telescopic cylinder.

[0040] The metal hose to be welded in this embodiment is a metal bellows with a G1 / 2 threaded connection structure, as shown in 7, including a G1 / 2 joint assembly 401, a socket-type threaded joint assembly 405, a bellows 403, a buckling ring 402, and a PVC coating 404. The G1 / 2 joint assembly 401 is composed of a welding pipe 4011 and a G1 / 2 nut 4012. 2-3 waves are reserved at both ends. The buckling ring 402 is inserted before welding, and the end of the bellows is butt-welded to the welding pipe 4011.

[0041] When welding with the protective welding device for the metal hose joint of the cooker of the present embodiment, first place the long length of the bellows assembly with the plastic wrapped bellows on the welding workbench, take out one end of the bellows assembly and put the buckle ring on the tail end of the coating layer, so that the tail end of the buckle ring fits with the tail end of the coating layer and exposes 2-3 complete waves for easy welding, pull out the positioning slider to the rightmost end of the guide core rod, and put the assembled joint assembly into the semi-circular positioning recess at the right end of the positioning slider (see Figure 8 Then, align one end of the assembled bellows with the tail end of the welding pipe in the semi-circular positioning recess, move the bellows assembly toward the closed cavity to the closed cavity positioning end cover, start the welding gun telescopic positioning unit to automatically lower the welding gun to the butt welding position of the welding pipe and the bellows (see Fig. 9 ), and introduce protective gas for welding pre-protection. After that, start the argon arc welding butt welding, rotate the bellows body assembly for 360° circular welding after the spot welding is completed, turn off the argon arc welding after the welding is completed, stay in the closed chamber for 1-3s, then raise the welding gun, turn off the protective gas, and pull out the welded end of the metal bellows along the guide core rod, and at the same time take out the positioning slider from the closed chamber. Then turn around and repeat the above process to weld the other end.

[0042] Embodiment 2

[0043] The basic structure of the protective welding device for the metal hose joint of the stove in this embodiment is the same as that in the embodiment. The difference is that the metal hose to be welded is as follows: Fig.10 As shown, it is a metal bellows with a socket-type threaded connection structure, which includes a socket-type threaded joint assembly 405, a bellows 403, a buckling ring 402, and a PVC coating layer 404. The socket-type threaded assembly 405 is composed of a socket thread 4052 and a welding pipe 4051. The bellows 403 is coated with a layer of PVC coating layer 404 and 2-3 waves are reserved at both ends. The buckling ring 402 is inserted into the two ends before welding, and the end of the bellows is butt-welded with the welding pipe 4051. For this purpose, the joint assembly positioning unit 3 is as shown in FIG. Fig.11 and Fig.12 As shown, it includes a guide core rod 303, a locking nut 301, and a socket-type positioning slider 304, so the slider body of the positioning slider 304 is slightly different from that of the first embodiment.

[0044] Practice shows that the above-mentioned metal hose joint protection welding device for stoves in this embodiment has the following advantages:

[0045] 1. The joint shielded welding process is used for metal bellows welding, which integrates multiple processes such as shielded welding, rapid clamping and feeding, and automatic positioning. The two joint component structures can be quickly replaced with metal hose tooling for stoves, which effectively improves the welding quality and positioning accuracy. Compared with the traditional welding process, the shielded welding device provides precise automatic positioning technology, welding process atmosphere protection atmosphere and joint component rapid feeding mechanism, which solves the problems of poor weld quality, high degree of oxidation, difficult welding gun positioning and low welding efficiency in traditional welding.

[0046] 2. The special structural design of the pipe thread and the socket-type thread positioning slider mechanism cleverly solves the problem of feeding the joint assembly, and brings the joint assembly into the closed cavity during the pipe feeding process. The semi-annular structure can be withdrawn together after welding. At the same time, it can ensure that the nut does not move during the welding process to interfere with the welding.

[0047] 3. Relying on the ventilation interface mechanism, the functions of active gas filling protection during welding, rapid cooling of welding, and automatic gas shut-off after welding can be realized. Cheap protective gases such as nitrogen can be used to reduce the cost of protective gas, while ensuring the quality of product welding appearance.

[0048] 4. The specially designed closed cavity unit has real-time observation of the welding process. The welding gun inlet is sealed with flexible silicone rubber. The membrane valve structure is used for the tube inlet to solve the feeding and sealing problems of large joint nuts and small tubes. The minimized cavity design is adopted to achieve the minimum leakage of shielding gas and maximum shielding welding during the welding process.

[0049] 5. The welding gun telescopic positioning unit can realize precise automatic positioning of the welding point, solving the problems of poor manual positioning accuracy and low welding efficiency. At the same time, a unique post-welding dwell time control is set, that is, the gun will not be lifted if the post-welding protection time is insufficient, which effectively improves the welding quality.

[0050] 6. The closed cavity welding protection mechanism design can minimize the damage to the human body caused by the leakage of argon arc welding arc. At the same time, the closed cavity is equipped with a welding observation port to conveniently observe the welding process. The closed cavity can also effectively collect the dust generated during the welding process to reduce the hazard of dust inhalation by operators.

[0051] In addition to the above embodiments, the present invention may also have other implementation modes. Any technical solution formed by equivalent replacement or equivalent transformation falls within the protection scope required by the present invention.

Claims

1. A metal hose joint protection welding device, characterized in that: It comprises a closed cavity unit (2) having a welding observation port (204) on one side and a welding gun telescopic positioning unit (5), wherein the upper part of the closed cavity unit (2) has a welding gun insertion hole; The two ends of the hollow sealed chamber (205) of the sealed chamber unit are respectively provided with a positioning end cap (202) and an insertion end cap (210); The positioning end cover fixes a guide core rod (303) that passes through the sealed chamber and extends out of the positioning end cover, and the outer circle of the guide core rod matches the diameter of the metal bellows; The guide core rod is provided with a positioning slide block (302) which forms a horizontal moving pair therewith, and the outer section of the positioning slide block has a centering recess which matches the shape of the head assembly to be welded; The central perforation of the insertion end cap is provided with a membrane valve rubber sealing pad (209), the membrane valve rubber sealing pad is composed of a group of rubber sheets with fixed outer ends and elastically closed inner ends; The membrane valve rubber sealing gasket is composed of a group of trapezoidal rubber sheets with long sides as outer ends fixed to the central perforated circle of the insertion end cover and short sides as inner ends elastically closed. The adjacent waists of each trapezoidal rubber sheet are mutually matched, and the short sides of each trapezoidal rubber sheet form a positioning slider insertion hole with a closed diameter matching the positioning core rod.

2. The metal hose joint protection welding device according to claim 1 is characterized in that: The lower side of the guide core rod is provided with an axially extending keyway, and the positioning slider is provided with a dynamic fitting convex key structure embedded in the keyway.

3. The metal hose joint protection welding device according to claim 2 is characterized in that: The upper part of the outer section of the slider body of the positioning slider is open, and the lower part is provided with an axial limiting centering recess matching the shape of the head assembly to be welded.

4. The metal hose joint protection welding device according to claim 3 is characterized in that: The upper part of the closed cavity unit is fixed with a welding gun sealing gasket by means of a strong magnetic block, and the middle part of the welding gun sealing gasket is provided with a welding gun insertion hole.

5. The metal hose joint protection welding device according to claim 4 is characterized in that: The welding gun telescopic positioning unit is arranged on one side of the closed cavity unit, and comprises a welding gun clamp and a telescopic cylinder; the welding gun clamp is installed at the telescopic moving end of the telescopic cylinder, the gun body of the welding gun is fixed in the clamping hole of the welding gun clamp, and the gun head extends into the welding gun insertion hole.

6. The metal hose joint protection welding device according to claim 5 is characterized in that: The front side of the hollow sealed chamber is provided with a welding observation port for inserting an arc light filtering eyepiece.

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