Welding apparatus for welding a weld stud to a substrate with gas distribution

Abstract

A welding device for welding a weld stud to a base material along a weld axis in a welding direction is provided, the welding device comprising an inert gas cap having a welding chamber and comprising a holding device for holding the weld stud within the welding chamber during a welding operation, wherein the inert gas cap has an input channel (355), a distribution chamber (356), a plurality of first connection channels (350) and an inert gas inlet into the welding chamber, wherein an inert gas feed line can be connected to the input channel (355), wherein the input channel (355) opens into the distribution chamber (356), wherein the first connection channels (350) open into the distribution chamber (356) at different distances from the input channel (355), wherein the first connection channels (350) pneumatically connect the distribution chamber (356) to an inert gas outlet, and wherein the common cross-sectional area of the first connection channels (356) is greater the greater the distance of the first connection channels (356) from the input channel (355) at the distribution chamber (356).

Description

Technical Field

[0001] This invention generally relates to a welding apparatus for welding welding studs to a substrate along a welding axis in a welding direction. In particular, this invention relates to a welding torch. Background Technology

[0002] Various known devices and methods exist for securing different types of studs to a substrate in different applications. For example, a stud is brought into contact with the substrate and an electric current is applied to it. For this purpose, the stud is held in place by a conductive stud holder. Once the current flows between the stud and the substrate, the stud is lifted from the substrate to form an electric arc. The released energy causes partial liquefaction of the materials of both the stud and the substrate. The current is then disconnected, and the stud is immersed in the liquefied material, which cools and solidifies. The stud is thus integrally bonded to the substrate.

[0003] To provide the energy necessary to liquefy the material of the stud and substrate in a sufficiently short time, there are known devices that generate a very high current intensity and feed this current to the stud using a suitably regulated cable. To prevent oxidation of the liquefied material, it is known to surround the contact point between the stud and the substrate with an inert gas. In this case, the inert gas flows through the weld joint along with the liquefied material, displacing any oxygen present there from the surrounding air.

[0004] For example, in construction or shipbuilding applications, various sizes of studs with threads for tightening objects onto them are used to secure the objects to the substrate. Summary of the Invention

[0005] The object of the present invention is to provide an improved device for fastening bolts to a substrate.

[0006] A welding apparatus for welding a weld stud to a substrate along a welding axis in a welding direction includes an inert gas cover having a welding chamber and a holding device for holding the weld stud within the welding chamber during welding operations. The inert gas cover has an inlet channel, a distribution chamber, a plurality of first connecting channels, and an inert gas inlet to the welding chamber. An inert gas feed line can be connected to the inlet channel, which leads to the distribution chamber. The first connecting channels lead to the distribution chamber at different distances from the inlet channel, and these first connecting channels pneumatically connect the distribution chamber to an inert gas outlet. In this welding apparatus, this objective is achieved by the fact that the greater the distance of the first connecting channels from the inlet channel to the distribution chamber, the larger the common cross-sectional area of ​​these first connecting channels. This partially compensates for the less exposure of those first connecting channels located at greater distances from the inlet channel. Therefore, in some cases, the inert gas flows more uniformly to the welding point. The welding apparatus is preferably configured as a welding torch.

[0007] An advantageous embodiment is characterized in that the greater the distance between the first connecting channels and the input channel at the distribution chamber, the larger the cross-sectional area of ​​all the discrete first connecting channels. Another advantageous embodiment is characterized in that the greater the distance between the first connecting channels and the input channel at the distribution chamber, the greater the density of all the discrete first connecting channels.

[0008] An advantageous embodiment is characterized in that the inert gas inlet includes a plurality of inlet openings arranged in a ring around the welding axis.

[0009] An advantageous embodiment is characterized in that these first connecting channels extend substantially parallel to the welding axis. Another advantageous embodiment is characterized in that these first connecting channels are arranged in a loop around the welding axis. Yet another advantageous embodiment is characterized in that the distribution chamber is formed in a loop around the welding axis.

[0010] An advantageous embodiment is characterized in that these first connection channels lead to the welding chamber and extend to the inert gas inlet.

[0011] An advantageous embodiment is characterized in that the inert gas cover has a collection chamber and a plurality of second connecting channels, wherein the first and second connecting channels lead to the collection chamber, and wherein the second connecting channels pneumatically connect the collection chamber to the inert gas inlet. Preferably, the common cross-sectional area of ​​the second connecting channels is smaller than the common cross-sectional area of ​​the first connecting channels. Also preferably, the second connecting channels extend substantially parallel to the welding axis. Also preferably, the second connecting channels are arranged in a loop around the welding axis. Also preferably, the collection chamber is formed in a loop around the welding axis. Also preferably, the second connecting channels lead to the welding chamber and extend to the inert gas inlet.

[0012] An advantageous embodiment is characterized in that the inert gas cap has an opening facing the welding direction. Attached Figure Description

[0013] The invention will now be explained in more detail based on exemplary embodiments and with reference to the accompanying drawings, in which:

[0014] Figure 1 The welding apparatus is shown schematically.

[0015] Figure 2 The welding apparatus is schematically shown in a partial longitudinal cross-sectional view.

[0016] Figure 3 The distribution room is shown schematically.

[0017] Figure 4 The collection room was shown.

[0018] Figure 5 The inert gas cap is schematically shown in an expanded longitudinal cross-sectional view, and

[0019] Figure 6 The inert gas cap is schematically shown in an expanded longitudinal cross-sectional view. Detailed Implementation

[0020] Figure 1 The image schematically illustrates a welding apparatus 10 for welding a welding stud 20 to a substrate 30. The materials of the welding stud 20 and the substrate 30 are conductive, particularly metallic. The welding apparatus 10 includes: a welding torch 40 having a trigger switch 41 formed as a push-button switch; a welding unit 50; a first cable 61; a second cable 62 with connecting terminals 63; a power supply cable 64 formed as, for example, an electrical cable; a communication wire 65; a gas reservoir 70 formed as a gas cylinder; a tubular gas supply line 71; and a gas hose 72.

[0021] A first cable 61 is used to supply current to the welding stud 20 through the welding unit 50. A second cable 62 is used to electrically connect the substrate 30 to the welding unit 50 when the connecting terminal 63 is clamped onto the substrate 30. When the welding stud 20 contacts the substrate 30, the circuit is closed, allowing welding current, such as direct current or alternating current, to be applied to the welding stud 20 through the welding unit 50. For this purpose, the welding torch 40 includes a welding current contact element (…). Figure 1 (Not shown in the image). The welding unit 50 includes means (not shown) for converting current from the power supply cable 64 into welding current. These means include, for example, a capacitor, a thyristor, a bipolar transistor with an isolation gate electrode, or other components belonging to power electronics, as well as an associated control unit with a microprocessor, to provide welding current at the desired voltage and current intensity.

[0022] Gas supply line 71 and gas hose 72 are used to supply inert gas from gas reservoir 70 to the contact area between welding stud 20 and substrate 30 to protect the contact area from oxidation by oxygen in the surrounding area during welding operations. To control the gas flow to the contact area, gas reservoir 70, gas supply line 71, welding unit 50, gas hose 72, or welding torch 40 include valves (not shown), particularly controllable valves.

[0023] The welding unit 50 has an input device 51 with an actuation element 52 and an output device 53 with a visual display element 54 and a wireless transmission unit. The input device 51 is used by the user of the welding device 10 to input parameters of the welding method to be performed using the welding device 10, such as the voltage, current intensity, power, and duration of the welding current, the position and speed of the welding stud, etc. The output device 53 is used to output information to the user, such as information about the parameters of the welding method, information about detected emissions or other variables of the welding method, information about the quality of the welding operation, information about measures to improve the welding operation, information about the detected characteristics of the welding stud or information derived from the above variables, and / or suggestions or guidance for cleaning and / or maintaining the welding device 10 (especially the welding torch 40).

[0024] Communication cable 65 is used in the control device of welding torch 40, particularly welding torch 40. Figure 1 (Not shown) Communication occurs between the welding torch and the welding unit 50, particularly the control unit and / or input device 51 and / or output device 53. This communication is used, for example, to exchange information about welding operation parameters so as to, for example, achieve or facilitate synchronization of the welding current with the movement of the welding stud 20. In an exemplary embodiment (not shown), communication between the welding torch and the welding unit is conducted wirelessly via radio or via a first cable carrying the welding current.

[0025] The welding torch 40 has a housing 42 with an opening 46, from which a handle 43 with a trigger switch 41 extends. The welding torch 40 also has a stud holder 44 on which the welding stud 20 is held during welding operations. For this purpose, the stud holder includes, for example, two, three, four, or more resilient arms (not shown in detail), to which the welding stud 20 is inserted and held between by means of a clamping engagement. To apply welding current to the welding stud 20, the welding torch 40 also has a welding current contact element, for example, integrated into the stud holder 44 in the form of one or more of these resilient arms.

[0026] The welding torch 40 also has a control device 99 for controlling these different components and devices of the welding torch and the welding unit 50. The control device 99 is intended to control one or more parameters of the welding operation. For this purpose, the control device 99 includes a variety of different electronic components, such as one or more microprocessors, one or more temporary or permanent data memories, etc.

[0027] The welding torch 40 also has a stud lifting device, which is formed as a first lifting magnet, and when the stud lifting device is activated, it causes the back-exit opening 46 to move backward. Figure 1 An upward force is applied to the stud holder 44. The control device 99 communicates with the stud lifting device via a signal line (not shown) to control the stud lifting device, specifically to activate and deactivate it.

[0028] The welding torch 40 also has a stud lowering device, which is formed as a spring element or a second lifting magnet. When the stud lowering device is activated, it causes the stud to move forward toward the opening 46. Figure 1 A downward force acts on the stud holder 44. The control device 99 communicates with the stud settling device via a signal line (not shown) to control the stud settling device, specifically to activate and deactivate it. If the stud settling device is configured as a spring element, this spring element is preferably tensioned when the stud holder moves backward via the stud lifting device, so that once the stud lifting device is deactivated, the spring element causes the stud holder to move forward.

[0029] In the welding method using welding apparatus 10, a substrate 30 and a stud 20 are first provided. In a further step, the user inputs information, such as desired parameters for subsequent welding operations, via an input device. In a further step, welding current is applied to the stud 20 and the substrate 30 via welding unit 50 using a first cable 61 and a second cable 62. In a further step, the stud 20 is lifted from the substrate using a stud lifting device while maintaining the flow of welding current between the stud 20 and the substrate 30, forming an electric arc between them. Specifically, due to the heat generated by the electric arc, the material of the stud 20 and / or the substrate 30 is partially liquefied. In a further step, the stud 20 is lowered into the liquefied material of the stud 20 or the substrate 30 using a stud settling device. Then, the liquefied material of the stud 20 or the substrate 30 solidifies, causing the stud 20 to be integrally bonded to the substrate 30.

[0030] Figure 2 A longitudinal section of a welding apparatus 100 is schematically shown, designed for welding a welding stud 120 to a substrate 130 along a welding axis 105 in a welding direction 110. The welding apparatus 100 is configured as a welding torch defining the welding direction 110. The welding apparatus 100 has a holding device 144 configured as a stud holder with an outer diameter dA and a stud receiving portion 121 with an inner diameter dI for holding the welding stud 120 during welding operations. The welding stud 120 can be inserted into the stud receiving portion and is preferably held by clamping action. The contact surface 125 of the welding stud 120 contacts the substrate 130 before and / or during the welding operation.

[0031] The welding apparatus 100 includes a housing 101, schematically shown, having a handle (not shown), a trigger switch (not shown), and an inert gas cover 140 designed to be filled with inert gas to suppress or completely prevent oxidation of the weld melt by oxygen from the surrounding air. For this purpose, the inert gas cover 140 has an inert gas supply section including an input channel 155, a distribution chamber 156, and a plurality of first connecting channels 150 arranged in a ring around the welding axis 105. An inert gas feed line (e.g., an inert gas hose 145, etc.) for supplying the inert gas cover 140 can be connected to the input channel 155.

[0032] Each of the first connecting channels 150 extending parallel to the welding axis 105 leads to the welding chamber 141 of the inert gas cover 140 via an inlet opening 160, such that the inlet openings 160 are also arranged in a ring around the welding axis 105 and together form an inert gas inlet. The input channel 155 and the first connecting channels 150 lead to the distribution chamber 156, wherein the first connecting channels 150 pneumatically connect the distribution chamber 156 to the inert gas inlet. The greater the distance of the first connecting channels 150 from the input channel 155 towards the distribution chamber 156, the larger the cross-sectional area of ​​each of the individual first connecting channels 150. The pressure drop on the distribution chamber 156, formed in a ring around the welding axis 105, away from the input channel 155 results in those first connecting channels 150 located at a greater distance from the input channel 155 (…). Figure 2 The area on the upper right side is less exposed. This less exposure is partially compensated by the increased cross-sectional area. Therefore, in some cases, the inert gas flows more uniformly to the weld point.

[0033] Furthermore, the inert gas cover 140 has a plurality of outlet openings 170, which are also arranged in a ring around the welding axis, radially passing through the inert gas cover 140 relative to the welding axis 105 and opening outwards into the surrounding area, forming inert gas outlets. In the direction transverse to the welding axis 105 (in... Figure 2 (in the plane perpendicular to the attached figure), particularly in the circumferential direction, the outlet opening 170 is arranged to be offset from the inlet opening 160.

[0034] Furthermore, the inert gas cover 140 has an opening 180 facing the welding direction 110 and having an opening diameter dM transverse to the welding direction 110. An inert gas inlet (specifically, inlet opening 160) is located at an inlet distance aE from opening 180 along the opposite direction of welding direction 110. An inert gas outlet (specifically, outlet opening 170) is located at an outlet distance aA from opening 180 along the opposite direction of welding direction 110.

[0035] The outlet distance aA is approximately half the difference between the opening diameter dM and the inner diameter dI, that is, approximately the same as the radial distance x between the welding stud 120 and the inert gas cap 140. Furthermore, the outlet distance aA is greater than the inlet distance aE. When the opening 180 is covered by the substrate 130, the inert gas flowing through the inlet opening 160 into the welding chamber 141 flows along the flow path 190 first to the radially outer region of the opening 180, then radially inward from all sides to the welding stud 120, and then substantially axially upward to the outlet opening 170. This results in the formation of an annular flow pattern arranged radially symmetrically around the welding axis 105, and has the effect of uniformly and effectively surrounding the weld point at the welding stud 120 with inert gas. For example, only slowly from the narrow gap between the retaining device 144 and the inert gas cap (in... Figure 2 The surrounding air escaping from the outlet opening 170 is entrained by the flow passing through the outlet opening 170 and moved away from the welding point.

[0036] exist Figure 3 The diagram schematically illustrates a distribution chamber 256 of another exemplary embodiment, with the viewing direction aligned with the welding direction. An input channel 255 and a plurality of first connecting channels 250 lead to the distribution chamber 256. The greater the distance of the first connecting channel 250 from the input channel 255 as it approaches the distribution chamber 256, the greater the density of all the discrete first connecting channels 250. The closest to the input channel 255 (… Figure 3 In the middle (at the bottom), only a single first connection channel 250 is arranged. In contrast, as seen from the input channel 255, a larger group of first connection channels 250, which are closer together, is arranged on the opposite side of the distribution chamber 256. Figure 3 (At the top). Therefore, the greater the distance between the first connecting channel 250 and the input channel 255 leading to the distribution chamber 256, the larger the total common cross-sectional area of ​​the first connecting channel 250.

[0037] exist Figure 4 The diagram illustrates the point. Figure 3 The collection chamber 266 shown in the exemplary embodiment is viewed from the same direction as the welding direction. Besides... Figure 4 In addition to the first connecting channel (not shown), a plurality of second connecting channels 270 also lead to the collection chamber 266. The second connecting channels 270 are arranged in a ring around the welding axis and are evenly distributed around the circumference of the collection chamber 266, which is also arranged in a ring around the welding axis. The number of second connecting channels 270 is less than [a certain value]. Figure 3The number of first connecting channels 250 shown is such that the common cross-sectional area of ​​the second connecting channels 270 is smaller than the common cross-sectional area of ​​the first connecting channels 250. Therefore, in some cases, the flow rate of the inert gas flowing through the first connecting channels 250 and the second connecting channels 270 is more uniform. This, in turn, has the effect of more uniform exposure of the weld joints (not shown) to the inert gas.

[0038] exist Figure 5 The inert gas cover 340 is shown in an expanded longitudinal sectional view, allowing the flow channels to be seen arranged along the circumference of the generally cylindrical, particularly circular, inert gas cover 340. The inert gas cover 340 includes an inlet channel 355, a distribution chamber 356, a plurality of first connecting channels 350, a collection chamber 366, and a plurality of second connecting channels 370. The inlet channel 355 leads to the distribution chamber 356. The first connecting channels 350 lead to the distribution chamber 356 on one side and to the collection chamber 366 on the other. The second connecting channels 370 lead to the collection chamber 366 on one side and to a welding chamber (not shown further) on the other, extending to an inlet opening 360 forming the inert gas inlet. The inlet channel 355, the first connecting channels 350, and the second connecting channels 370 extend substantially parallel to the welding axis and pneumatically connect the inert gas feed line connected to the inlet channel 355 to the welding chamber of the inert gas cover 340.

[0039] As the distance from the input channel 355 increases, the first connecting channels 350 are arranged in an increasing group, such that the greater the distance from the input channel 355 to the distribution chamber 356, the greater the density of the first connecting channels 350. Therefore, the greater the distance from the input channel 355 to the distribution chamber 356, the larger the common cross-sectional area of ​​the first connecting channels 350. As explained above with respect to the preceding exemplary embodiments, in some cases, the inert gas flows more uniformly to the welding point.

[0040] exist Figure 6The inert gas cover 440 is shown in an expanded longitudinal sectional view, allowing the flow channels to be seen arranged along the circumference of the generally cylindrical, particularly circular, inert gas cover 440. The inert gas cover 440 includes an inlet channel 455, a distribution chamber 456, a plurality of first connecting channels 450, a collection chamber 466, and a plurality of second connecting channels 470. The inlet channel 455 leads to the distribution chamber 456. The first connecting channels 450 lead to the distribution chamber 456 on one side and to the collection chamber 466 on the other. The second connecting channels 470 lead to the collection chamber 466 on one side and to a welding chamber (not shown further) on the other, extending to an inlet opening 460 forming the inert gas inlet. The inlet channel 455, the first connecting channels 450, and the second connecting channels 470 extend substantially parallel to the welding axis and pneumatically connect the inert gas feed line connected to the inlet channel 455 to the welding chamber of the inert gas cover 440.

[0041] As the distance from the input channel 455 increases, the distance from the input channel 455 at the point where the first connecting channel 450 leads to the distribution chamber 456 also increases, resulting in a larger cross-sectional area for each of the discrete first connecting channels 450. Therefore, the greater the distance from the input channel 455 at the point where the first connecting channel 450 leads to the distribution chamber 456, the larger the common cross-sectional area of ​​the first connecting channels 450 also becomes. As explained above with respect to the preceding exemplary embodiments, in some cases, the inert gas flows more uniformly to the welding point.

[0042] The invention has been described based on an example using a welding torch. In this case, the features of the described embodiments can also be combined with each other as desired within a single fastening device. It should be noted that the device according to the invention is also suitable for other purposes.

Claims

1. A welding apparatus for welding a weld stud to a substrate along a welding axis in a welding direction, the welding apparatus comprising an inert gas cover having a welding chamber, and a holding device for holding the weld stud within the welding chamber during welding operations, wherein, The inert gas cover has an input channel, a distribution chamber, a plurality of first connecting channels, and an inert gas inlet to the welding chamber, wherein an inert gas feed line is connectable to the input channel, wherein the input channel leads to the distribution chamber, wherein the first connecting channels lead to the distribution chamber at different distances from the input channel, wherein the first connecting channels pneumatically connect the distribution chamber to an inert gas outlet, characterized in that the greater the distance of the first connecting channels from the input channel to the distribution chamber, the larger the common cross-sectional area of ​​all the first connecting channels, wherein the inert gas cover has an opening facing the welding direction, wherein the inert gas inlet is at an inlet distance from the opening in the opposite direction of the welding direction, and the inert gas outlet is at an outlet distance from the opening in the opposite direction of the welding direction, wherein the outlet distance is greater than the inlet distance.

2. The welding apparatus as claimed in claim 1, wherein, The greater the distance between these first connection channels and the input channel at the distribution room, the larger the cross-sectional area of ​​all the separate first connection channels.

3. The welding apparatus according to any one of claims 1 to 2, wherein, The greater the distance between these first connection channels and the input channel at the distribution room, the greater the density of all the separate first connection channels.

4. The welding apparatus according to any one of claims 1 to 2, wherein, The inert gas inlet includes multiple inlet openings arranged in a ring around the welding axis.

5. The welding apparatus according to any one of claims 1 to 2, wherein, These first connection channels extend substantially parallel to the welding axis.

6. The welding apparatus according to any one of claims 1 to 2, wherein, These first connection channels are arranged in a ring around the welding axis.

7. The welding apparatus according to any one of claims 1 to 2, wherein, The distribution chamber is formed in the form of a ring around the welding axis.

8. The welding apparatus according to any one of claims 1 to 2, wherein, These first connection channels lead to the welding chamber and extend to the inert gas inlet.

9. The welding apparatus according to any one of claims 1 to 2, wherein, The inert gas cover has a collection chamber and a plurality of second connection channels, wherein the first connection channels and the second connection channels lead to the collection chamber and wherein the second connection channels pneumatically connect the collection chamber to the inert gas inlet.

10. The welding apparatus as claimed in claim 9, wherein, The common cross-sectional area of ​​these second connecting channels is smaller than the common cross-sectional area of ​​these first connecting channels.

11. The welding apparatus as claimed in claim 9, wherein, These second connection channels extend substantially parallel to the welding axis.

12. The welding apparatus as claimed in claim 9, wherein, These second connection channels are arranged in a ring around the welding axis.

13. The welding apparatus as claimed in claim 9, wherein, The collection chamber is formed in the form of a ring around the welding axis.

14. The welding apparatus as claimed in claim 9, wherein, These second connection channels lead to the welding chamber and extend to the inert gas inlet.

15. The welding apparatus according to any one of claims 1 to 2, wherein, The welding device is a welding torch.

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