A preheating device for welding that can perform multi-point heating simultaneously

Abstract

The present invention provides a preheating device for welding that can perform multi-point heating simultaneously, which includes a main pipe, a preheater, a hose, a mounting bracket, a spring, a branch pipe, and a handle. Among them, on the body of the main pipe, there is a preheater with an arc-shaped outlet end. The preheater is connected to the main pipe through a hose and is installed on the mounting bracket in a hinged form, and the mounting bracket is fixed on the main pipe; one end of the preheater is connected to a spring, and the other end of the spring is connected to the mounting bracket; the unclosed end of the main pipe is connected to the branch pipe, and the branch pipe is connected to a combustible gas source; meanwhile, a handle is also provided on the side wall of the main pipe. The present invention utilizes the wall attachment effect of the arc-shaped surface of the preheater port to guide the combustible gas to spray towards both sides, so that the deflagration wave formed by ignition on one side serves as the excitation source of the elastic system, causing the preheater to perform reciprocating swings while spraying flames, thereby forming uniform heating in a linear area, and implementing high-efficiency, high-precision, and high-uniformity preheating before welding for large workpieces, having good economic and practical value.

Description

Technical Field

[0001] The present invention belongs to the technical field of welding processing equipment, and particularly relates to a preheating device for welding that can perform multi-point heating simultaneously. Background Art

[0002] Preheating before welding is a technological measure to appropriately heat the local and overall parts of the welded part before welding. Its purpose is to reduce the cooling rate of the welding joint, avoid the formation of hardened structure, and reduce welding stress and deformation. It is an effective method to prevent the generation of welding cracks. Flame heating is one of the main methods of preheating before welding. For steel plates with poor weldability and large thickness, generally, the joint restraint is large, the welding heat conductivity is high, and ordinary non-low hydrogen type welding materials are used for welding, so preheating before welding should be carried out. Preheating before welding increases energy consumption. Therefore, under permitted conditions, low-temperature preheating welding should be adopted. A surface contact thermometer should be used to measure the temperature within the range of 30 - 50 mm on both sides of the area to be welded. To maintain the temperature of the welded part, continuous preheating is required, which consumes a large amount of manual labor and gas resources. And due to the limitation of operation difficulty, the heated temperature of the preheating area is often uneven, affecting the welding quality. Therefore, a new technical solution is needed to solve such problems.

[0003] Design a preheating device for welding that can perform multi-point heating simultaneously, maintain the temperature of the welding area, reduce gas consumption, and improve construction efficiency. Summary of the Invention

[0004] Aiming at the deficiencies in the above-mentioned prior art, the present invention provides a preheating device for welding that can perform multi-point heating simultaneously to achieve energy conservation and high efficiency of preheating before welding.

[0005] The present invention is implemented through the following technical solutions: A preheating device for welding that can heat multiple points simultaneously, comprising a main pipe, at least one preheater, at least one hose, at least one mounting bracket, at least one spring, a branch pipe, and a handle. Among them, the main pipe is a hollow pipe body with one end closed, and a plurality of the preheaters are arranged on its pipe body in a linear array. The inner wall of the outlet end of the preheater is provided with an arc surface. The inner cavities of the preheaters are all connected to the inner cavity of the main pipe through the hoses. The preheaters as a whole are installed on the mounting bracket in a hinged form, and the mounting bracket is fixed on the main pipe; the outer shell of each preheater is connected to one end of at least one of the springs, and the other end of the spring is connected to the mounting bracket; the unclosed end of the other end of the main pipe is connected to the branch pipe, and the branch pipe is connected to a combustible gas source storing combustible gas; meanwhile, a handle is also provided on the side wall of the main pipe; when the combustible gas flows into the inner cavity of the preheater through the above connection, the wall attachment effect caused by the arc surface at the outlet end of the preheater guides the combustible gas to one side of the arc surface, and ignition is carried out in the nearby area, thereby causing a unidirectional impact force on the preheater. Using the unidirectional impact force as the excitation source for the free vibration of the elastic system connected by the spring, the preheater performs a reciprocating swing while outputting a heating flame.

[0006] Further, the preheater includes a rotating shell, a nozzle, and a partition. Among them, the rotating shell is a hollow shell and is installed on the fixed shaft of the mounting bracket in a hinged form. One end of the rotating shell is connected to the main pipe through the hose, and the other end is connected to the nozzle. The end of the nozzle is provided with a flat trumpet-shaped opening, and flow guiding plates with arc-shaped inner walls are provided on both sides of its end. The partition is installed in the center of the inner cavity of the nozzle through a bracket.

[0007] Further, a plurality of the overall combinations of the preheater, the hose, the mounting bracket, and the spring are arranged on the main pipe body in an equidistant array manner in the arrangement direction of the main pipe body. The design spacing of the equidistant array can ensure that the flame ejected by any one preheater can meet the flash point conditions required for the combustible gas ejected by the adjacent preheater.

[0008] Further, when the elastic system composed of the spring and the preheater performs free vibration, the linear velocity at the end of the swing of the preheater is greater than the flow velocity of the combustible gas ejected from the end of the preheater.

[0009] Further, the combustible gas stored in the combustible gas source connected by the branch pipe is propane or acetylene.

[0010] Further, the spring is a tension spring, and both sides of the outer shell of each nozzle are respectively connected to the ends of one of the springs.

[0011] Further, the rotating shell and the fixed shaft are made of the same metal material. A flame arrester is installed between the rotating shell and the hose. The flame arrester can block the flame propagation in the inner cavity of the nozzle through the wall effect formed by a plurality of narrow channels in its inner cavity.

[0012] Furthermore, the curve deflection angle of any arc on the inner wall of the deflector is within the range of 0 to 95°.

[0013] Furthermore, at the position where the deflector extends to the nozzle port, the angle between the tangent line tangent to its arc-shaped inner wall and the horizontal plane is within the range of ±20°.

[0014] Furthermore, the ratio of the section of the partition plate exceeding the end face of the nozzle to its entire length is within the range of 1:3 to 1:6.

[0015] The beneficial effects of the present invention are as follows:

[0016] 1. In the present invention, combustible gas is ejected from the preheater and ignited to form a heating flame. At the same time, the wall attachment effect of the port deflector is utilized to guide the initial flow of the combustible gas. The arc-shaped inner walls on both sides of the inner cavity of the preheater port adsorb the initial air flow and make it spray toward both sides. Thus, the unidirectional deflagration wave formed by ignition on either side serves as the excitation source of the elastic system where the spring is located, causing the preheater to swing reciprocally along the fixed axis while spraying the heating flame, thereby uniformly heating the workpiece in a linear area. By simultaneously swinging multiple preheaters arranged linearly at equal intervals, high-efficiency, high-precision, and high-uniformity pre-welding preheating measures are implemented for large workpieces in an automatic linear heating mode, overcoming the disadvantages of the existing point heating technology, such as cumbersome operation, uneven temperature, and waste of materials. At the same time, it effectively saves labor and reduces gas consumption, and thus completes high-quality preheating and welding processes, having good economic and practical value.

[0017] 2. The mechanism for driving the preheater to swing in the present invention belongs to a pure mechanical structure without electric assistance and is arranged outside its housing. The swing system is independently arranged from the gas path system, and a hose provides flexibility for the nozzle in the swinging state. With designs such as connecting and hinging with a flame arrester of the same material for guarantee, it maximally suppresses the factors of flashback and static electricity, has high operation safety, is convenient to operate, has low cost, is easy to manufacture and implement, and can be used for heating or surface treatment operations in other fields besides pre-welding preheating, having high applicability, and is a new type of device worthy of promotion. Description of the Drawings

[0018] Figure 1 is the overall structural schematic diagram of the present invention;

[0019] Figure 2 is the partial assembly schematic diagram of the preheater in the present invention;

[0020] Figure 3 is the axonometric drawing of the preheater in the present invention;

[0021] Figure 4Schematic diagram of the ignition state of the present invention;

[0022] Figure 5 Schematic diagram of the swinging state of the present invention.

[0023] In the figure: 1 - main pipe, 2 - preheater, 21 - rotating shell, 22 - nozzle, 22a - deflector, 23 - partition plate, 24 - flame arrester, 3 - hose, 4 - mounting bracket, 4a - fixed shaft, 5 - spring, 6 - branch pipe, 7 - handle. Detailed implementation manners

[0024] The present invention will be further described in detail below in conjunction with the accompanying drawings of the specification and embodiments.

[0025] Embodiment 1

[0026] As Figures 1-3 shown, a preheating device for pre - welding that can perform multi - point heating simultaneously includes a main pipe 1, four preheaters 2, four hoses 3, four mounting brackets 4, eight springs 5, a branch pipe 6, and a handle 7. Among them, the main pipe 1 is a hollow pipe body with one end closed, and four of the preheaters 2 are equidistantly arranged on its pipe body in a linear array. The preheater 2 includes a rotating shell 21, a nozzle 22, a partition plate 23, and a flame arrester 24. Among them, the rotating shell 21 is a hollow shell and is hingedly installed on the fixed shaft 4a made of the same metal material on the mounting bracket 4. One end of the rotating shell 21 is connected to the main pipe 1 through the hose 3, and the other end is connected to the nozzle 22. The end of the nozzle 22 has a flat trumpet - shaped opening, and deflectors 22a with arc - shaped inner walls are provided on both sides of its end. Figure 2 shown, the curve deflection angle of the inner wall arc of the deflector 22a is 75°, and the included angle between the inner wall tangent of the deflector 22a at the port and the horizontal plane is 15°. The partition plate 23 is installed in the center of the nozzle 22 cavity between the two deflectors 22a through a bracket, and the ratio of the section of the partition plate 23 exceeding the end face of the nozzle 22 to its entire length is 1:4; a flame arrester 24 is installed between the rotating shell 21 and the hose 3, and the flame arrester 24 can block the flame propagation in the nozzle 22 cavity through the wall effect formed by multiple narrow channels in its inner cavity; the spring 5 is a tension spring 5, and both sides of the shell of each nozzle 22 are respectively connected to the ends of one of the springs 5, and the other end of the spring 5 is connected to the mounting bracket 4, and the mounting bracket 4 is welded and fixed on the main pipe 1; the unclosed end of the main pipe 1 is connected to the branch pipe 6, and the branch pipe 6 is connected to a combustible gas source with propane as the component; at the same time, a handle 7 is also provided on the side wall of the main pipe 1.

[0027] The specific implementation steps of this embodiment are as follows:

[0028] Step 1: Turn on the switch of the combustible gas source connected to the branch pipe 6, so that propane gas enters the inner cavity of the main pipe 1 at a certain pressure. When the propane combustible gas flows into the inner cavity of the nozzle 22 of the preheater 2 through the connection of the hose 3 and the flame arrester 24, as Figure 4 shown, by using the wall attachment effect caused by the inner wall arc surface of the deflector 22a on the initial air flow, part of the downwardly ejected propane combustible gas is adsorbed and its original ejection direction is offset, thereby guiding the initial air flow to flow along the inner wall arc surfaces of the left and right deflectors 22a. Since the curve deflection angle of the inner wall arc of the deflector 22a is designed to be 75°, it can effectively prevent the arc surface curvature from being too large, and thus ensure the smooth progress of the wall attachment effect; at this time, ignition is carried out in the Figure 4 A point area shown, and the propane gas flow concentrated near the left (direction according to Figure 4 ) deflector 22a is ignited. At the moment when the combustion reaction has not entered the right side area of the partition 23, the one-way impact force caused by the left deflagration wave instantly pushes the partition 23 and the entire preheater 2, so that the preheater 2 swings to the right with the fixed shaft 4a as the axis, and serves as the excitation source for the free vibration of the elastic system connected by the two springs 5, so that the preheater 2 swings reciprocally at a certain frequency while outputting the ejected flame.

[0029] Step 2: When the preheater 2 is ignited and continuously burned according to the operation in Step 1, since part of the propane gas also sprays out from the center of the nozzle 22, and the ratio of the length of the partition 23 exceeding the end face of the nozzle 22 to its entire length is 1:4, the combustion reaction of the left deflector 22a can cross the partition 23 and be transmitted from outside the nozzle 22 to the right side of the partition 23, and then continuously output the heating flame in the entire inner cavity of the nozzle 22 while the preheater 2 swings to the right, as Figure 5 shown, when the right side (direction according to Figure 5)When the flow deflector 22a causes the right - hand airflow trajectory to shift to the right due to its wall - attachment effect, since the flow deflector 22a itself swings to the right along with the nozzle 22 at this time, the flow velocity of the right - hand airflow relative to the right - hand flow deflector 22a slows down. When the structural design of the elastic system composed of the pre - heater 2 and the spring 5 can ensure that the swinging speed of the nozzle 22 is greater than the flow velocity of the propane gas ejected from the nozzle 22, the right - hand airflow will be stationary relative to the right - hand flow deflector 22a or even move relatively to the left, greatly weakening the wall - attachment effect of the right - hand flow deflector 22a on the right - hand airflow. As a result, the impact force of the unidirectional deflagration wave caused by the right - hand offset airflow decreases; similarly, the contact between the left - hand flow deflector 22a and the left - hand airflow is more sufficient, enhancing the wall - attachment effect of the left - hand flow deflector 22a, so that the reverse thrust caused by the left - hand airflow and deflagration wave is greater than that on the right - hand side. Thus, when the whole pre - heater 2 is in the right - swing state, it will also receive an impact resultant force towards the right. When the right - swing state reaches the limit and the left - hand spring 5 starts to contract and drives the pre - heater 2 to swing to the left, similarly, the pre - heater 2 will receive an impact resultant force towards the left in the left - swing state, thereby maintaining the continuous operation of the left - and - right swinging of the pre - heater 2, and using the combustible gas itself to provide the driving force for the continuous swinging of the pre - heater 2.

[0030] Step three: As Figure 1 shown, when the left - most pre - heater 2 is ignited and made to swing continuously according to Steps 1 and 2, when it swings to the right - hand limit, its output flame will ignite the left - deflected airflow of the flow deflector 22a of the adjacent pre - heater 2 on the right - hand side. Then, similarly to Steps 1 and 2, it will drive the adjacent pre - heater 2 to output a heating flame and swing continuously. Similarly, the operator only needs to ignite one side of the pre - heater 2 to trigger the flame - spraying and swinging actions of all four pre - heaters 2 on the main pipe 1. Then, hold the handle and aim at the large workpiece, and use the continuous swinging of the four pre - heaters 2 to output a uniform linear heating flame to perform the pre - welding pre - heating operation on the large workpiece, and perform the welding operation in this uniform pre - heating state to obtain a high - quality welded product; when the operator holds the handle and moves it horizontally, the linear heating flame can also become a patch - type scanning heating along with the horizontal movement of the main pipe 1, so as to quickly pre - heat the entire area of the large workpiece and meet the welding requirements in various situations.

[0031] Embodiment 2

[0032] The difference between this embodiment and Embodiment 1 is that the number of pre - heaters 2, hoses 3, and mounting brackets 4 is one each, the number of springs 5 is only two, and the combustible gas stored in the combustible gas source connected by the branch pipe 6 is acetylene. As Figure 2As shown, in the same manner as in Embodiment 1, the swinging and flame-jetting states of the preheater 2 are ignited and started. Since only one preheater 2 is provided, the designed length of the main pipe 1 is shorter. The operator can hold the handle with one hand to perform linear preheating operations on small workpieces or local areas in complex environments, or hold the handle and move in a direction perpendicular to the body of the main pipe 1 to perform pre-welding preheating or surface treatment operations on small workpieces that are difficult to install.

[0033] Embodiment 3

[0034] The difference between this embodiment and Embodiment 1 is that the overall device of the present invention is installed on a moving bracket with a reciprocating linear motion function. In the same manner as in Embodiment 1, the swinging and flame-jetting states of the four preheaters 2 are ignited and started. When the driving device of the moving bracket is started to make the main pipe 1 perform reciprocating linear motion in a direction perpendicular to its body, the four preheaters 2 will also perform reciprocating linear motion along with the main pipe 1 in the swinging and flame-jetting state. Under the interleaved motion of reciprocating swing and reciprocating linear movement while spraying flames, an extremely uniform heating effect is generated on a square area, thereby implementing high-quality pre-welding preheating or surface heat treatment operations.

[0035] The above are only the preferred embodiments of the present invention, and do not constitute a formal limitation on the present invention. For those skilled in the art, various equivalent replacements made by using the features of the claims of the present invention shall fall within the protection scope of the present invention.

Claims

1. A preheating device for preheating before welding that can perform multi-point heating simultaneously, comprising a main pipe, at least one preheater, at least one hose, at least one mounting bracket, at least one spring, a branch pipe, and a handle, characterized in that: The main pipe is a hollow tube body with one end closed. A plurality of the preheaters are arranged on its pipe body in a linear array. The inner wall of the outlet end of the preheater is provided with an arc surface. The inner cavities of the preheaters are all communicated with the inner cavity of the main pipe through the hoses. The preheaters as a whole are installed on the mounting frame in a hinged form. The mounting frame is fixed on the main pipe. The outer shell of each preheater is connected to one end of at least one of the springs, and the other end of the spring is connected to the mounting frame. The unclosed end of the other end of the main pipe is connected to the branch pipe. The branch pipe is connected to a combustible gas source storing combustible gas. At the same time, a handle is also provided on the side wall of the main pipe. When the combustible gas flows into the inner cavity of the preheater, the wall attachment effect caused by the arc surface at the outlet end of the preheater guides the combustible gas to one side of the arc surface, and ignition is carried out in the nearby area, thereby causing a unidirectional impact force on the preheater. Using the unidirectional impact force as the excitation source for the free vibration of the elastic system connected by the spring, the preheater performs a reciprocating swing while outputting a heating flame; The preheater includes a rotating shell, a nozzle, and a partition. Among them, the rotating shell is a hollow shell and is installed on the fixed shaft of the mounting frame in a hinged form. One end of the rotating shell is connected to the main pipe through the hose, and the other end is connected to the nozzle. The end of the nozzle is provided with a flat trumpet-shaped opening, and flow guiding plates with arc-shaped inner walls are provided on both sides of its end. The partition is installed in the center of the inner cavity of the nozzle through a bracket; A plurality of the overall assemblies composed of the preheater, the hose, the mounting frame, and the spring are arranged in an equidistant array in the arrangement direction of the main pipe body. The design spacing of the equidistant array can ensure that the flame sprayed by any one preheater can meet the flash point conditions required for the combustible gas sprayed by the adjacent preheater.

2. The preheating device for pre-welding capable of multi-point heating simultaneously according to claim 1, wherein: When the elastic system composed of the spring and the preheater performs free vibration, the linear velocity at the end of the swing of the preheater is greater than the flow velocity of the combustible gas ejected from the end of the preheater.

3. The preheating device for pre-welding capable of multi-point heating simultaneously according to claim 1, wherein: The combustible gas stored in the combustible gas source connected by the branch pipe is propane or acetylene.

4. The preheating device for welding before welding capable of simultaneously heating multiple points as described in claim 1, wherein: The spring is a tension spring. Both sides of the outer shell of each nozzle are connected to the ends of one spring respectively.

5. The preheating device for preheating before welding capable of multi-point heating simultaneously according to claim 1, wherein: The rotating shell and the fixed shaft are made of the same metal material. A flame arrester is installed between the rotating shell and the hose. The flame arrester can block the flame propagation in the inner cavity of the nozzle through the wall effect formed by a plurality of narrow channels in its inner cavity.

6. The preheating device for preheating before welding capable of multi-point heating simultaneously according to claim 1, wherein: The curve deflection angle of any arc on the inner wall of the flow guiding plate is within the range of 0 to 95°.

7. The preheating device for welding before welding capable of multi-point heating simultaneously as described in claim 1, wherein: At the position where the flow guiding plate extends to the nozzle port, the angle between the tangent line tangent to its arc-shaped inner wall and the horizontal plane is within the range of ±20°.

8. The preheating device for welding that can perform multi-point heating simultaneously as described in claim 1, characterized in that: The ratio of the section of the partition exceeding the end face of the nozzle to its entire length is within the range of 1:3 to 1:6.

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