CN110576238A - Impact rolling machine head for welding and welding-following device - Google Patents

Abstract

The invention relates to the field of welding, in particular to an impact rolling machine head for welding and a welding device. This along with welding the device includes: an air pump and an impact rolling machine head for welding. The shell of the impact rolling machine head for welding is provided with an air inlet, the cylinder is arranged in the shell, and the piston divides the cylinder into an upper space and a lower space; the upper end of the impact rod passes through the bottom wall of the cylinder in a sliding manner and extends into the lower space, and the lower end of the impact rod is connected with a rolling wheel structure; the rolling wheel structure comprises a rolling cam and a rolling concave wheel, the rolling concave wheel is arranged at the front end of the moving direction of the impact rolling machine head for welding, and the rolling cam is arranged at the rear end of the moving direction of the impact rolling machine head for welding. The piston in the cylinder is pushed to move by using gas pressure, mechanical impact force is applied to weld metal in a high-temperature state, the melt in a welding high-temperature area is extruded to the middle through the rolling concave wheel, and transverse rolling is performed through the rolling cam when the melt is cooled, so that the aims of preventing welding hot cracks from occurring in a weld area and delaying cold cracks are fulfilled.

Description

Impact rolling machine head for welding and welding-following device

Technical Field

The invention relates to the field of welding, in particular to an impact rolling machine head for welding and a follow-up welding device.

background

during welding, the welded structure generates large stress, and the welded structure is easy to generate large deformation and even generate cracks. The welding stress poses a great threat to the safety of the structure. The low-alloy high-steel has excellent mechanical property, can bear higher-level working load, is widely applied to a plurality of fields such as aerospace, national defense and military, rail transit and the like, and is often used as an important bearing structure material in products. However, the low-alloy high-strength steel has poor weldability, which mainly reflects that the welding stress deformation is large, thermal cracks and delayed cracks are easy to appear, the shape correction and the heat treatment are needed after welding, the production cost is increased, the product quality is influenced, particularly the delayed cracks are caused, and great potential safety hazards are brought to the service work of the product structure.

in the case of welding hot cracks, the welding hot cracks are common problems in the welding process and are main defects of welded components. The welding hot crack mainly refers to the crack generated when the weld seam and the heat affected zone metal are cooled to a high temperature zone near the solidus line in the welding process. Thermal cracks, also known as crystallographic cracks or solidification cracks, often occur during the crystallization of the weld.

In order to solve the problems, various methods such as welding-following rolling, static and dynamic temperature difference stretching and the like and devices for realizing the methods are proposed at home and abroad, and even high-cost anti-cracking welding materials are adopted. The methods and devices generally have low production efficiency, high cost and poor working environment, particularly along with a welding rolling method, the phenomena of large equipment, large size of an impact rolling wheel, mutual interference of welding guns and easy generation of arc striking exist, and the methods and devices are difficult to be used for actual production. The impact method along with welding has the defects that the deflection and the vibration of the hammer head are large and a guide mechanism needs to be added.

disclosure of Invention

Technical problem to be solved

the invention aims to provide an impact rolling machine head for welding and a follow-up welding device, which are used for solving the problem of welding with hot cracks or cold cracks in follow-up welding.

(II) technical scheme

In order to solve the above technical problems, the present invention provides an impact rolling machine head for welding, comprising:

The shell is provided with an air inlet;

The air cylinder is arranged in the shell, a piston which can freely move up and down in the air cylinder divides the air cylinder into an upper space and a lower space, the upper space is provided with an air inlet, the air inlet is communicated with the air inlet, the upper space is provided with an air outlet, and the air outlet is provided with an exhaust control valve; the lower space is provided with an exhaust hole;

The upper end of the impact structure penetrates through the bottom wall of the air cylinder in a sliding mode and extends into the lower space, and the lower end of the impact structure is connected with a rolling wheel structure;

The rolling wheel structure includes: the rolling cam is positioned at the front end of the moving direction of the impact rolling machine head for welding, and the rolling cam is positioned at the rear end of the moving direction of the impact rolling machine head for welding; the rolling surface of the rolling cam is an outer convex surface, and the rolling surface of the rolling concave wheel is an inner concave surface.

In some embodiments, preferably, the rolling wheel structure further comprises a rolling wheel support, and a middle region of the rolling wheel support is rotatably connected with the lower end of the impact structure through a pin shaft;

The two ends of the rolling wheel support are respectively fixed with a mounting clamp, the bottom of the mounting clamp is provided with a long hole, and the wheel shaft of the rolling cam and the wheel shaft of the rolling concave wheel can be vertically installed in the corresponding long holes in a floating manner.

in some embodiments, preferably, the rolling wheel structure further includes a torsion spring, the torsion spring is mounted on the pin shaft, and two branches of the torsion spring are respectively connected with the axle of the rolling cam and the axle of the rolling concave wheel.

In some embodiments, it is preferable that a lower portion of the impact structure is provided with a support arm, and a reset member is provided between the support arm and the bottom wall of the cylinder.

in some embodiments, preferably, the impact rolling machine head for welding further comprises a shock absorption seat, and an inner groove is formed in the lower surface of the shock absorption seat; in the casing, the outside of cylinder sets up the air hammer casing, the top surface of air hammer casing is the epirelief curved surface, the top surface embedding of air hammer casing in the inner groovy.

In some embodiments, preferably, the welding impact crushing machine head further comprises a damping spring, and two ends of the damping spring respectively abut against the upper surface of the damping seat and the inner top surface of the shell.

in some embodiments, it is preferable that the exhaust control valve is opened when the air pressure in the upper space increases to a preset value; when the air pressure in the upper space is reduced to a preset value, the exhaust control valve is closed.

in some embodiments, preferably, the bottom wall of the cylinder is provided with an exhaust hole communicated with an external air supply system, and a lower fairing is arranged in the air outlet direction of the exhaust hole;

And/or the presence of a gas in the gas,

an upper fairing is arranged on the exhaust passage of the upper space.

the present invention also provides a follow-up welding apparatus, which, after being used for welding a torch at the time of welding, comprises: the air pump with the welding with strikeing the aircraft nose that rolls, the end of giving vent to anger of air pump with the welding is with strikeing the income gas port in the upper portion space of rolling the aircraft nose and communicating.

In some embodiments, preferably, the welding-following device further comprises: at least one air cylinder, a speed regulating valve; the air outlet end of the air pump is communicated with the air inlet of the upper space of the impact rolling machine head for welding through a speed regulating valve;

The air outlet end of the air pump is provided with a far-end air storage cylinder, and/or the air inlet of the upper space is provided with a near-end air storage cylinder.

(III) advantageous effects

The welding-following device in the technical scheme provided by the invention is used for welding a gun during welding and comprises the following components: the air pump and the welding are with strikeing the aircraft nose that rolls, and the end of giving vent to anger of air pump communicates with the income gas port of the upper portion space of the aircraft nose that rolls with strikeing to weld. The impact crusher head for welding includes: the shell is provided with an air inlet; the air cylinder is arranged in the shell, the piston divides the air cylinder into an upper space and a lower space, the upper space is provided with an air inlet, an air inlet is communicated with an air inlet, the upper space is provided with an air outlet, and the air outlet is provided with an exhaust control valve; the lower space is communicated with an external air supply system; the upper end of the impact structure passes through the bottom wall of the cylinder in a sliding manner and extends into the lower space, and the lower end of the impact structure is connected with the rolling wheel structure; the rolling wheel structure includes: the rolling cam is positioned at the front end of the moving direction of the impact rolling machine head for welding, and the rolling cam is positioned at the rear end of the moving direction of the impact rolling machine head for welding; the rolling surface of the rolling cam is an outer convex surface, and the rolling surface of the rolling concave wheel is an inner concave surface. The piston in the cylinder is pushed to move by using gas pressure, mechanical impact force is applied to weld metal in a high-temperature state, melt in a welding high-temperature area is extruded towards the middle by the rolling concave wheel, and transverse rolling is performed by the rolling cam when the melt is cooled, so that the plastic flow of the weld metal is regulated and controlled, the residual compressive strain is reduced, the tensile residual stress generated in the cooling process of the weld metal is reduced, and the aims of preventing welding hot cracks and delaying cold cracks in a weld area are fulfilled.

From the mechanical point of view, the aim of controlling welding hot cracks is achieved mainly by improving the stress state during welding. In the welding process, certain transverse extrusion strain is additionally applied to metal in a brittle temperature range in a welding seam so as to offset inherent cracking tensile strain in the welding seam and achieve the purpose of controlling welding hot cracks.

The invention has the advantages of simple and small equipment, stable and reliable work, long service life, convenient use, low cost and good joint quality, can control the stress of a straight welding line and a closed welding line, effectively reduces the residual tensile stress of the surface to be below 10 percent, and even can change the tensile stress of the surface into a compressive stress state to prevent the occurrence of welding hot cracks and delayed cold cracks.

Drawings

FIG. 1 is a schematic structural diagram of a follow-up welding apparatus according to an embodiment of the present invention;

FIG. 2 is a schematic view of an impact crusher head for welding according to an embodiment of the present invention;

FIG. 3 is a schematic longitudinal cross-sectional view of a crushing concave wheel according to an embodiment of the invention;

FIG. 4 is a schematic longitudinal cross-sectional view of a crushing cam in one embodiment of the invention;

FIG. 5 is a schematic view showing the flow direction of the air flow in the upper space when the exhaust control valve is not opened;

Fig. 6 is a schematic view showing the flow direction of the air flow in the upper space when the exhaust control valve is opened.

In the figure:

1. An air pump; 2. a pressure reducing valve; 3. a distal air cylinder; 4. a relay; 5. a speed regulating valve; 6. a proximal air cylinder; 7. impacting a rolling machine head; 8. a housing; 9. a shock absorbing seat; 10. a piston; 11. an impact bar; 12. an upper cowl; 13. a lower cowling; 14. a pin shaft; 15. a wheel axle; 16. rolling the cam; 16-1, annular bulge; 17. a damping spring; 18. an air hammer; 19. an exhaust control valve; 20. a cylinder; 21. an air exhaust hole is formed in the air cylinder; 22. an exhaust hole; 23. a strong pressure spring; 24. a workpiece; 25. installing a clamp; 26. a torsion spring; 27. a rolling wheel support; 28. rolling a concave wheel; 28-1, circumferential grooves; 29. a high temperature flame.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. "first", "second", "third" and "fourth" do not denote any sequence relationship, but are merely used for convenience of description. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art. "Current" is the time at which an action is performed, multiple occurrences of which are recorded in real time over time.

The present invention provides an impact rolling machine head for welding, which is used for a welding-following device, as shown in figures 1-6, and comprises: casing 8, cylinder 20, impact structure, roll the wheel structure, wherein, casing 8 sets up the gas inlet, communicates with outside air supply system. The cylinder 20 is arranged in the shell 8, the piston 10 divides the cylinder 20 into an upper space and a lower space, the upper space is provided with an air inlet, an air inlet is communicated with an air inlet, the upper space is provided with an air outlet, and the air outlet is provided with an exhaust control valve; the lower space is communicated with an external air supply system; the upper end of the impact rod 11 passes through the bottom wall of the cylinder 20 in a sliding manner and extends into the lower space, and the lower end of the impact rod is connected with a rolling wheel structure; the rolling wheel structure includes: the rolling cam 16 and the rolling concave wheel 28, wherein the rolling concave wheel 28 is arranged at the front end of the moving direction of the impact rolling machine head for welding, and the rolling cam 16 is arranged at the rear end of the moving direction of the impact rolling machine head for welding; as shown in fig. 4, the rolling surface of the rolling cam 16 is convex, and as shown in fig. 3, the rolling surface of the rolling concave wheel 28 is concave.

The impact structure can select the impact rod 11, or the impact column, the impact block, etc., the piston 10 in the cylinder 20 freely moves in the cylinder 20, and changes the gas pressure in the upper space of the cylinder 20, because the gas inlet of the upper space of the cylinder 20 is communicated with the gas inlet of the shell 8, so that the external gas supply system supplies gas to the upper space, the supplied gas pressure is influenced by the motion effect of the piston 10, the lower space of the cylinder 20 is communicated with the external gas supply system, and the gas pressure is the same as the pressure of the external gas supply system, therefore, the pressure difference exists between the gas pressure in the upper space and the gas pressure in the lower space of the cylinder 20, so that the piston 10 can move up and down under the action of the gas pressure, when the piston 10 moves down, the impact rod 11 is pushed to move down, the impact rod 11 drives the rolling wheel structure to act downwards, the rolling concave wheel 28 acts on the high-, the rolling cam 16 is used for carrying out transverse rolling to regulate and control plastic flow of weld metal, reduce residual compressive strain and reduce tensile residual stress generated in the cooling process of the weld metal, thereby achieving the purposes of preventing welding hot cracks and delaying cold cracks in a weld area.

As shown in fig. 5 and 6, when the piston 10 moves upward, the air pressure in the upper space of the cylinder 20 increases, when the preset value is reached, the exhaust control valve opens, the air in the upper space of the cylinder 20 is exhausted, the air pressure in the upper space of the cylinder 20 decreases, when the preset value is reached, the exhaust control valve closes under the action of the air pressure, the air supply of the external air supply system continues to be received in the upper space of the cylinder 20, the air pressure gradually increases, when the air pressure reaches a certain value, the air pressure pushes the piston 10 to move downward, and when the piston 10 moves downward, the impact rod 11 is pushed to move downward. When the piston 10 pushes the striking rod 11 downwards, it is simultaneously forced upwards, and in certain cases the piston 10 moves upwards, starting a new cycle.

In order to effectively fix the rolling cam 16 and the rolling concave wheel 28 and form an effective linkage relationship, the rolling wheel structure further comprises a rolling wheel support, and the middle area of the rolling wheel support is rotatably connected with the lower end of the impact rod 11 through a pin shaft; the two ends of the rolling wheel support are respectively fixed with a mounting clamp, the bottom of the mounting clamp is provided with a long hole, and the wheel shaft of the rolling cam 16 and the wheel shaft of the rolling concave wheel 28 can be vertically installed in the corresponding long holes in a floating manner. The axle of the rolling cam 16 and the axle of the rolling concave wheel 28 float up and down in the long hole along with the acting force of the rolling melt and the impact rod 11, and particularly, when the piston 10 moves up and down again, the rolling wheel support slightly moves up along with the piston 10, and the axle of the rolling cam 16 and the axle of the rolling concave wheel 28 descend to the bottom of the long hole and are positioned at the middle upper part of the long hole when not being impacted.

The lower extreme of impact bar 11 is connected with the middle part of rolling wheel support 27 by round pin axle 14, and the front and back both ends of rolling wheel support 27 are fixed with mounting clip 25 respectively, and the mounting clip can be with rolling the cam, rolling between its two centre gripping arms of concave wheel centre gripping, avoids rolling the cam, rolling the concave wheel and rotates, takes place the route skew when marcing, plays the effect of direction. The front end mounting clip is fixed with a grinding concave wheel 28 by a wheel shaft 15, and the rear end mounting clip is fixed with a grinding cam 16 by a wheel shaft.

in order to effectively fix the positions of the rolling cam 16 and the rolling concave wheel 28 and obtain effective reset, the rolling wheel structure further comprises a torsion spring 26, the torsion spring 26 is mounted on the pin shaft 14, and two branches of the torsion spring 26 are respectively connected with the axle 15 of the rolling cam 16 and the axle 15 of the rolling concave wheel 28.

As shown in FIG. 3, the concave rolling wheel 28 is provided with a circumferential groove 28-1 on the curved surface, i.e. the concave rolling surface is an inner concave surface. As shown in fig. 4, the rolling cam 16 is provided with a circumferential protrusion 16-1 on the curved surface, i.e. the rolling surface is an outer convex surface.

As can be seen from the shape of the contact surface of the crush box 28 (which acts as the front wheel as it moves with the torch) with the workpiece, this impact force can be resolved into a longitudinal component that presses back and forth down the periphery of the wheel and a transverse component that presses down the inner recess of the front wheel toward the center of the weld.

as shown in figure 3, because the area acted by the front wheel impact rolling compaction force is closer to a welding pool, the temperature is relatively higher, and the temperature of the metal on the inner side of the area acted by the front wheel impact rolling compaction force is higher than that on the outer side, the metal in the acting area is more favorable for flowing to the center of a welding seam in the transverse direction, so that when the front wheel impacts downwards, the transverse extrusion strain is applied to the metal in a brittle temperature area, the tensile strain capable of cracking is offset, and the purpose of preventing welding hot cracks is achieved. As shown in fig. 4, the rolling cam 16 (serving as a rear wheel when moving with the welding torch) is convex in shape and is pressed tightly against the weld during operation, and when the rolling wheel support 27 impacts downward, the rolling cam 16 gives an impact rolling force to the weld, and as can be seen from the shape of the contact surface of the rear wheel with the workpiece, this impact force can be decomposed into a longitudinal component force pressing downward and forward and backward in the circumferential direction of the wheel and a lateral component force pressing downward and toward both sides of the weld along the convex surface of the rear wheel, and the lateral component force is larger than the longitudinal component force due to the difference between the longitudinal and lateral radii of curvature. Therefore, the longitudinal and transverse directions generated by cooling and shrinking of the weld metal can be fully extended, and the welding residual stress is reduced, so that the purpose of preventing and controlling the welding cold cracks is achieved.

In order to push the impact rod 11 to move upwards and reset, a support arm is arranged at the lower part of the impact rod 11, and a reset piece is arranged between the support arm and the bottom wall of the cylinder.

the support arm can be understood as a spring seat, and moves synchronously with the impact rod 11, so that the resilience force of the reset piece is changed, and the acting force of the reset piece on the impact rod 11 is adjusted. In some cases the return element is preferably a strong compression spring 23 or an elastic rubber or the like. And a strong pressure spring 23 penetrates through the impact rod, one end of the strong pressure spring is contacted with the bottom wall of the cylinder, and the other end of the strong pressure spring is contacted with the upper surface of the support arm.

Because the support arm is close to the bottom wall of the cylinder 20, the bottom wall of the cylinder 20 is provided with an exhaust hole to realize the communication between the lower space of the cylinder and an external air supply system, the support arm can be provided with a lower fairing 13, or the support arm can be directly used as the lower fairing 13 to rectify the gas exhausted from the lower space and guide the gas to be exhausted according to a specified path.

A strong pressure spring 23 is arranged on the impact rod 11 between the lower fairing 13 and the bottom end of the cylinder 20, an exhaust hole 22 is arranged at the lower end of the cylinder 20, an air cylinder upper exhaust hole 21 is arranged at the side end of the cylinder 20, and the air cylinder upper exhaust hole 21 is communicated with the air hole on the shell 8. In some embodiments, an upper cowl 12 is also provided in the exhaust passage of the upper space to guide the flow of gas as well. Meanwhile, the upper fairing 12 and the lower fairing 13 both have the noise reduction effect to a certain extent.

Above the cylinder, in order to reduce the upward impact force of the impact rolling machine head for welding, the device also comprises a shock absorption seat 9, and the lower surface of the shock absorption seat 9 is provided with an inner groove; in the casing 8, set up the air hammer casing in the outside of cylinder 20, the top surface of air hammer casing is the epirelief curved surface, and the top surface embedding inner groovy of air hammer casing is in. The impact rolling machine head for welding further comprises a damping spring 17, and two ends of the damping spring 17 respectively support against the upper surface of the damping seat 9 and the inner top surface of the shell 8.

the air hammer 18 is fixed in the middle of the shell 8, the shock absorption seat 9 is fixed in the shell 8 at the upper part of the air hammer 18, and the shock absorption spring 17 is arranged between the upper part of the shock absorption seat 9 and the top cover of the shell 8.

Example 1:

An impact rolling machine head for welding comprises a shell 8, a shock absorption seat 9, a piston 10, an impact rod 11, an upper fairing 12, a lower fairing 13, a pin shaft 14, a wheel shaft 15, a rolling cam 16, a shock absorption spring 17, an air hammer 18, an exhaust control valve 19, an air cylinder 20, an air exhaust hole 21 in the air cylinder, an exhaust hole 22, a strong pressure spring 23, a rolling wheel support bracket, a mounting clamp 25, a torsion spring 26, a rolling wheel support 27 and a rolling concave wheel 28.

An air hammer 18 is fixed in the middle of the inside of a shell 8, a shock absorption seat 9 is fixed in the shell 8 at the upper part of the air hammer 18, a shock absorption spring 17 is arranged between the upper part of the shock absorption seat 9 and the top cover of the shell 8, an air cylinder 20 is fixed at the lower part of the air hammer 18, an exhaust control valve 19 is arranged at the upper part of the air cylinder 20, the exhaust control valve 19 is equivalent to a reversing valve, a piston 10 is arranged in the air cylinder 20, an impact rod 11 is arranged at the center of the air cylinder 20 at the lower part of the piston 10, an upper fairing 12 is fixed between the lower part of the outer side of the air cylinder 20 and the shell 8, a lower fairing 13 is arranged on the impact rod 11, a strong pressure spring 23 is arranged on the impact rod 11 between the lower fairing 13 and the bottom end of the air cylinder 20, an exhaust hole 22 is arranged at the lower end of the air cylinder 20, an air cylinder upper exhaust hole 21 is communicated, the front end and the rear end of the rolling wheel support 27 are respectively fixed with a mounting clamp 25, the mounting clamp 25 at the front end is fixed with a rolling concave wheel 28 by an impact rolling wheel shaft 15, the mounting clamp 25 at the rear end is fixed with a rolling cam 16 by the impact rolling wheel shaft 15, and the mounting clamps 25 at the front end and the rear end of the rolling wheel support 27 are provided with torsion springs 26. The curved surface of the rolling concave wheel 28 is provided with a circumferential groove 28-1. The curved surface of the rolling cam 16 is provided with a circumferential bulge 16-1.

The working process of the device of the invention is as follows: the air hammer impact piston 10 reciprocates up and down under the push of compressed air, when the piston moves to two end positions, an air flow control port is exposed, high-pressure air pushes an exhaust control valve 19 to act, the air charging and discharging directions of the air cylinder are changed, and the piston moves in the opposite direction. When the piston impacts downwards, the impact rod 11 is blocked at the tail end of the stroke, energy is transferred to the dowel bar at the moment of contact, the airflow is reversed, the piston starts to move upwards, the next impact cycle is started, and the impact rod drives the rolling wheel support 27 to impact downwards through the pin shaft 14. This impact force is transmitted through the mating faces of the roller block and the impact roller to the roller cam 16 and the roller dented wheel 28 and ultimately to the workpiece 24. When the piston impacts downwards, the impact rolling wheel is tightly pressed on the surface of a workpiece by huge impact force and does not move, and the workpiece and the impact rolling wheel move relatively in the horizontal direction, so that the comprehensive process of impact and rolling is realized; the impact action time is very short, when the impact process is finished, the rolling wheel seat and the impact rod are slightly bounced upwards under the action of the impact reaction force, and the rolling wheel is separated from the rear seat thereof and still pressed on the surface of the workpiece due to the pressure of the torsion spring 26 and rotates forwards along with the movement of the whole impact rolling mechanism (or the workpiece).

From the above, the impact rolling wheel actually does intermittent motion of one stop and one rotation, but because the working frequency (50-100Hz) of the mechanism is higher and the impact action time is very short, the mechanism can visually observe and feel that the impact rolling wheel continuously rotates when working. According to the shape of the contact surface of the front wheel and the workpiece, the impact force can be decomposed into a longitudinal component which is pressed forwards and backwards downwards along the wheel periphery and a transverse component which is pressed downwards along the concave surface of the front wheel towards the center of the welding seam. Because the area of the front wheel under the action of impact rolling force is closer to a welding pool, the temperature is relatively higher, and the temperature of the metal on the inner side of the area under the action of the impact rolling force of the front wheel is higher than that on the outer side, the metal in the area under the action of the impact rolling force of the front wheel is more favorable for flowing to the center of a welding seam in the transverse direction, so that when the front wheel impacts downwards, a transverse extrusion strain is applied to the metal in a brittle temperature range, the tensile strain which can cause cracking is offset, and the purpose of preventing welding thermal cracks. The rolling cam 16 is convex in shape and is tightly pressed on the welding seam part during operation, when the rolling wheel support 27 impacts downwards, the rolling cam 16 gives an impact rolling force to the welding seam, and the impact force can be decomposed into a longitudinal component which is pressed downwards and forwards along the wheel circumference direction and a transverse component which is pressed downwards and forwards along the convex surface of the rear wheel to the two sides of the welding seam, wherein the transverse component is larger than the longitudinal component due to the difference of longitudinal and transverse curvature radiuses. Therefore, the longitudinal and transverse directions generated by cooling and shrinking of the weld metal can be fully extended, and the welding residual stress is reduced, so that the purpose of preventing and controlling the welding cold cracks is achieved.

The exhaust control valve 19 operates on the principle: the exhaust control valve can be adjusted to open and close according to gas pressure in the cylinder, and when gas pressure in the cylinder is smaller, the exhaust control valve is closed, and the cylinder is in an isolated state with the external world, and when gas pressure in the cylinder is larger, the exhaust control valve is opened, and the cylinder is in a communicated state with the external world.

Piston operation exemplifies:

Working condition 1: the working condition 1 is an initial working condition, which is described by referring to fig. 5, the gas flow direction is detailed in fig. 5 when the piston initially works, gas in the air pump enters the cylinder, the gas pressure in the cylinder is lower at the moment, the exhaust control valve is closed, and the cylinder is in an isolated state with the outside. Along with the gas in the air pump continuously enters the air cylinder, the gas pressure in the air cylinder continuously increases, the air cylinder is pushed to move downwards, and the impact transmission rod is pushed to downwards apply impact force to the front rolling wheel and the rear rolling wheel.

Working condition 2: when the piston is at the lowest part, the gas pressure in the cylinder is continuously increased, when the rated pressure in the exhaust control valve is reached, the exhaust control valve is opened, the cylinder is connected with the outside, and the gas in the cylinder flows to the outside through the exhaust control valve. The gas flow direction in the piston is shown in detail in fig. 6, and at the moment, along with the reduction of the gas in the cylinder, the piston is quickly reset to the upper end of the cylinder under the action of the powerful pressure spring.

working condition 3: when the piston resets to cylinder upper portion, gas pressure reduces in the cylinder, and the exhaust control valve is closed, and the cylinder is in isolated state with external, and along with gas in the air pump constantly gets into the cylinder, gas pressure constantly increases in the cylinder, promotes the cylinder downstream to promote impact transmission pole and exert the impact force to front and back rolling wheel downwards.

The present invention also provides a follow-up welding apparatus, as shown in fig. 1, which, after being used in a welding torch at the time of welding, the welding torch discharges a high-temperature flame 29, comprising: the air pump and the impact rolling machine head for welding of any one of the embodiments are characterized in that an air outlet end of the air pump is communicated with an air inlet of an upper space of the impact rolling machine head for welding.

the device along with welding still includes: at least one air cylinder, a speed regulating valve; the air outlet end of the air pump is communicated with an air inlet of the upper space of the impact rolling machine head for welding through a speed regulating valve; the air outlet end of the air pump is provided with a far-end air storage cylinder, and/or the air inlet of the upper space is provided with a near-end air storage cylinder.

In addition, a pressure reducing valve 2 can be arranged between the air pump and the far-end air cylinder, a relay can be connected behind an air outlet of the far-end air cylinder and is communicated with a speed regulating valve 5, the speed regulating valve 5 is communicated with the near-end air cylinder, and the near-end air cylinder is communicated with the impact rolling machine head for welding.

Namely an air pump 1 of a welding-following device, a pressure reducing valve 2, a far-end air cylinder 3, a relay 4, a speed regulating valve 5, a near-end air cylinder 6 and an impact rolling machine head 7; the exit end of air pump 1 and the input fixed connection of relief pressure valve 2, the output of relief pressure valve 2 is connected with the one end of relay 4, be fixed with distal end gas receiver 3 between relief pressure valve 2 and relay 4, the other end of relay 4 and the input end fixed connection of governing valve 5, the play end of governing valve 5 with strike and roll by pipeline fixed connection between the aircraft nose 7, governing valve 5 with strike and roll and be fixed with near-end gas receiver 6 on the pipeline between the aircraft nose 7.

The far-end air storage cylinder 3 is arranged close to the air pump 1, and the near-end air storage cylinder 6 is arranged close to the impact rolling machine head 7, and the functions of the far-end air storage cylinder 3 and the near-end air storage cylinder 6 are to ensure the stability of air pressure and pneumatic impact force of the air hammer and are not interfered by pressure fluctuation of the air pump.

the speed regulating valve 5 is used for regulating the impact frequency and the impact force, so that a lower frequency and a smaller impact force can be adopted during welding arcing, and the stable start of the welding process is ensured.

The piston in the cylinder is pushed to move by using gas pressure, mechanical impact force is applied to weld metal in a high-temperature state, melt in a welding high-temperature area is extruded towards the middle by the rolling concave wheel, and transverse rolling is performed by the rolling cam when the melt is cooled, so that the plastic flow of the weld metal is regulated and controlled, the residual compressive strain is reduced, the tensile residual stress generated in the cooling process of the weld metal is reduced, and the aims of preventing welding hot cracks and delaying cold cracks in a weld area are fulfilled.

From the mechanical point of view, the aim of controlling welding hot cracks is achieved mainly by improving the stress state during welding. In the welding process, certain transverse extrusion strain is additionally applied to metal in a brittle temperature range in a welding seam so as to offset inherent cracking tensile strain in the welding seam and achieve the purpose of controlling welding hot cracks.

The invention has the advantages of simple and small equipment, stable and reliable work, long service life, convenient use, low cost and good joint quality, can control the stress of a straight welding line and a closed welding line, effectively reduces the residual tensile stress of the surface to be below 10 percent, and even can change the tensile stress of the surface into a compressive stress state to prevent the occurrence of welding hot cracks and delayed cold cracks.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims (10)

1. An impact crusher head for welding, comprising:

The shell is provided with an air inlet;

the air cylinder is arranged in the shell, a piston which can freely move up and down in the air cylinder divides the air cylinder into an upper space and a lower space, the upper space is provided with an air inlet, the air inlet is communicated with the air inlet, the upper space is provided with an air outlet, and the air outlet is provided with an exhaust control valve; the lower space is provided with an exhaust hole;

The upper end of the impact structure penetrates through the bottom wall of the air cylinder in a sliding mode and extends into the lower space, and the lower end of the impact structure is connected with a rolling wheel structure;

The rolling wheel structure includes: the rolling cam is positioned at the front end of the moving direction of the impact rolling machine head for welding, and the rolling cam is positioned at the rear end of the moving direction of the impact rolling machine head for welding; the rolling surface of the rolling cam is an outer convex surface, and the rolling surface of the rolling concave wheel is an inner concave surface.

2. The impact mill head for welding according to claim 1, wherein said mill wheel structure further comprises a mill wheel support, a middle region of said mill wheel support being rotatably connected to a lower end of said impact structure by a pin;

The two ends of the rolling wheel support are respectively fixed with a mounting clamp, the bottom of the mounting clamp is provided with a long hole, and the wheel shaft of the rolling cam and the wheel shaft of the rolling concave wheel can be vertically installed in the corresponding long holes in a floating manner.

3. The impact crusher head for welding according to claim 2, characterized in that said crusher structure further comprises a torsion spring, said torsion spring is mounted on said pin, and two branches of said torsion spring are connected to the axle of said crusher cam and the axle of said crusher concave wheel, respectively.

4. An impact crusher head for welding according to claim 1, characterized in that said lower part of said impact structure is provided with a support arm, and a return member is provided between said support arm and the bottom wall of said cylinder.

5. The impact crusher head for welding according to claim 1, further comprising a shock absorbing seat, wherein an inner groove is provided on a lower surface of said shock absorbing seat; in the casing, the outside of cylinder sets up the air hammer casing, the top surface of air hammer casing is the epirelief curved surface, the top surface embedding of air hammer casing in the inner groovy.

6. The welding impact crusher head according to claim 5, further comprising a damper spring, both ends of which are respectively abutted against an upper surface of said damper base and an inner top surface of said housing.

7. The impact crusher head for welding as claimed in any one of claims 1 to 6, wherein said exhaust control valve is opened when the air pressure in said upper space is increased to a predetermined value; when the air pressure in the upper space is reduced to a preset value, the exhaust control valve is closed.

8. the impact rolling machine head for welding according to any one of claims 1 to 6, wherein the bottom wall of the cylinder is provided with the exhaust hole communicated with an external air supply system, and a lower fairing is arranged in the air outlet direction of the exhaust hole;

And/or the presence of a gas in the gas,

An upper fairing is arranged on the exhaust passage of the upper space.

9. A follow-on device for use after a welding gun in welding, comprising: the air pump and the impact rolling machine head for welding as claimed in any one of claims 1 to 8, wherein an air outlet end of the air pump is communicated with an air inlet of an upper space of the impact rolling machine head for welding.

10. The follow on device of claim 9, further comprising: at least one air cylinder, a speed regulating valve; the air outlet end of the air pump is communicated with the air inlet of the upper space of the impact rolling machine head for welding through a speed regulating valve;

The air outlet end of the air pump is provided with a far-end air storage cylinder, and/or the air inlet of the upper space is provided with a near-end air storage cylinder.