Powder feed nozzle and welding device

Abstract

Powder feed nozzle (100) for a welding device, with a base body (110) which has a main section (111) and an outlet section (112) adjacent to the main section (111), wherein the outlet section (112) has an outlet opening (113), with at least one coolant supply line (115A, 115B, 115C) extending axially along the main section (111) and with at least one coolant discharge line (116A, 116B, 116C) extending axially along the main section (111), wherein the at least one coolant supply line (115A, 115B, 115C) and the at least one coolant discharge line (116A, 116B, 116C) are connected via at least two coolant connecting lines (117A, 117B, 117C) extending radially at least partially around the outlet section (112), characterized in that at least two coolant pairs (114A, 114B, 114C) are each provided with a coolant supply line (115A, 115B, 115C), a coolant discharge line (116A, 116B, 116C) and at least two coolant connecting lines (117A, 117B, 117C), wherein the coolant connecting lines (117A, 117B, 117C) of the individual coolant pairs (114A, 114B, 114C) are arranged parallel to each other in a row along at least one part of the length of the exit section (112).

Description

[0001] The invention relates to a powder feed nozzle for a welding device. Furthermore, the invention relates to a welding device with such a powder feed nozzle.

[0002] Powder feed nozzles of this type are typically used to supply a powder-gas mixture during a welding process. In a welding process, a weld pool is created on the surface of a component, into which a powdered filler material is introduced via a feed nozzle. The filler material melts, forming a layer on the component surface that is fused to the base material at the joint. Welding can be performed, for example, using a laser beam.

[0003] During the welding process, a high level of heat is generated, particularly high reflected heat, which affects the feed nozzle. It is therefore necessary to cool the feed nozzle during the welding process. However, feed nozzles are usually very long and have a very small diameter, which makes cooling such nozzles difficult.

[0004] German patent DE 26 51 185 A1 describes a cooling device for a plasma torch in which the nozzle is surrounded by a coolant flow. For this purpose, supply and discharge channels are located between the nozzle holder and a surrounding housing, through which the coolant is guided. The nozzle is externally equipped with fins to improve heat transfer and enable more efficient cooling. This design serves to reliably dissipate the extremely high temperatures of the plasma jet (up to several tens of thousands of degrees Celsius) generated by plasma torches.

[0005] DE 10 2017 215 839 A1 relates to an optical module for a machine for processing workpieces and / or for producing shaped parts by selectively solidifying material powder into contiguous areas using a laser beam. The optical module comprises a housing with means for detachably attaching the optical module to the machine and a collimation optics changer detachably arranged in the housing, with at least two collimation optics movable into a beam path of the laser beam for collimating the laser beam. According to the invention, the collimation optics changer has a mechanism for automatically changing the collimation optics.

[0006] The plasma generation system of US 4,780,591 A comprises a plasma gun with a hollow cylindrical anode element, a hollow cylindrical intermediate element that is electrically insulated and arranged coaxially to the anode element to form a plasma gas channel through the intermediate element and the anode element, and an axially movable cathode element. The intermediate element consists of tubular segments separated by elastic, pressurized insulating rings. The arc radiation is shielded from the spacer rings by meanders in the slots of the intermediate segments and additionally by ceramic barrier rings. An electric motor or a pneumatic piston, responding to a measurement of the arc voltage, continuously adjusts the axial position of the cathode tip relative to the anode nozzle to maintain a predetermined arc voltage.

[0007] German patent DE 41 20 790 A1 discloses a nozzle for the surface treatment of metallic workpieces, in which a protective gas and powder are guided through the nozzle to apply materials or to treat surfaces in a targeted manner. The design includes a guide for the powder and protective gas, a protective cap, and a special nozzle configuration to ensure uniform powder distribution and a stable protective gas flow. The device serves to process metallic surfaces more efficiently and uniformly using deposition processes such as coating, alloying, or similar methods.

[0008] WO 2018 / 132 566 A1 describes a laser soldering or laser brazing system which has a special design for cooling the wire feed.

[0009] US Patent 2014 / 0251973A1 discloses a cooled welding torch with a cooling circuit extending from a nozzle holder to a gas nozzle. The gas nozzle is attached to the welding torch by means of a defined rotation. The cooling circuit is guided by a deflector located above the nozzle holder, which can be rotated along with the gas nozzle. The path of the cooling circuit can be switched by the position of the gas nozzle.

[0010] US Patent 4,373,657 A discloses an automated device for feeding solder or brazing material (e.g., wire or strip) into a soldering or brazing process. The invention optimizes both thermal management and material feeding to enable more precise and faster soldering or brazing.

[0011] It is therefore the object of the present invention to provide a powder feed nozzle and a welding device in which the process can be further improved.

[0012] This problem is solved by the features of the independent claims. Advantageous embodiments and further developments of the invention are specified in the dependent claims.

[0013] The powder feed nozzle according to the invention has a base body comprising a main section and an outlet section adjacent to the main section, the outlet section having an outlet opening. Furthermore, the powder feed nozzle has at least one coolant supply line extending axially along the main section and at least one coolant discharge line extending axially along the main section, wherein the at least one coolant supply line and the at least one coolant discharge line are connected via at least two coolant connecting lines extending radially around the outlet section, at least partially.

[0014] A coolant supply line, a coolant discharge line, and at least two coolant connecting lines each form a coolant pair. Preferably, at least two coolant pairs are provided, each with a coolant supply line, a coolant discharge line, and at least two coolant connecting lines. By providing two or more such coolant pairs, the coolant supply volume can be increased. Despite the increased coolant supply volume, the space required for cooling can be kept small due to the distribution across a multitude of lines by the multiple coolant pairs, thus enabling particularly efficient cooling even with very narrow and compact supply nozzles. The coolant connecting lines of the individual coolant pairs are arranged parallel to each other in a row along at least a portion of the length of the outlet section.

[0015] The feed nozzle, also called a powder feed nozzle, can, for example, be a so-called off-axis nozzle. The powder feed nozzle has a preferably elongated body, which is divided into a main section and an outlet section adjacent to the main section. The powder-gas mixture flows through the body in such a way that it first flows through the main section, then from the main section into the outlet section, and exits the powder feed nozzle through the outlet opening to be applied to the weld pool on the component being welded. The body tapers, particularly in the area of ​​the outlet section, so that the diameter of the body is smallest in the area of ​​the outlet opening.To cool the powder feed nozzle, and in particular the nozzle body, the powder feed nozzle has at least one coolant supply line and at least one coolant discharge line. The coolant supply line and the coolant discharge line preferably run parallel to each other. Coolant, such as water, can be transported via the coolant supply line to the outlet section of the nozzle body, and the coolant, having absorbed heat, can be transported away from the outlet section via the coolant discharge line. In the area of ​​the outlet section of the nozzle body, the coolant supply line is connected to the coolant discharge line, allowing the coolant to flow from the supply line to the discharge line. At least two coolant connection lines are provided for this purpose, each extending between the coolant supply line and the coolant discharge line.Because each coolant supply line and each coolant outlet line are assigned two or more coolant connecting lines, the coolant flow is split into several coolant streams at the outlet section of the base unit. These streams then flow through the connecting lines and rejoin in the outlet line. By splitting the coolant flow exiting the supply line into several smaller streams at the connecting lines, highly focused cooling can be achieved at the outlet. Furthermore, this type of coolant stream splitting allows for a very compact cooling arrangement, particularly at the outlet, where the base unit is especially narrow and therefore has a very small diameter.In contrast to the coolant supply line and the coolant discharge line, which each extend axially along the length of the main section, the coolant connecting lines are essentially arranged in a spiral shape around the outlet section, so that they extend radially around the outlet section, at least in some areas.

[0016] Furthermore, it is preferably provided that the at least two coolant connecting lines each have a smaller diameter than the coolant supply line and the coolant discharge line. The smaller diameter allows several coolant connecting lines to be arranged side by side in a space-saving manner, so that a larger area can be effectively cooled than with just one coolant line having a larger diameter. In particular, in the narrow outlet section, the smaller diameter allows for a greater number of coolant connecting lines to be arranged, so that despite the narrow design of the outlet section, a large area or region of the outlet section can be effectively cooled.

[0017] The at least two coolant connection lines are preferably arranged such that each of them runs at an angle of 2° ≤ α ≤ 20° to a perpendicular axis of a longitudinal axis of the base body. Thus, the coolant connection lines preferably do not extend at exactly a 90° angle to the longitudinal axis of the base body, but are preferably arranged perpendicular to the perpendicular axis of the longitudinal axis, so that the coolant connection lines extend obliquely to the perpendicular axis of the longitudinal axis of the base body. This perpendicular arrangement of the coolant connection lines relative to the perpendicular axis of the longitudinal axis of the base body allows a flow direction to be determined for the coolant flowing through them.Furthermore, this angled arrangement allows the coolant connection lines to be longer, thus creating a larger surface area for heat absorption and further increasing heat dissipation from the outlet section.

[0018] In addition to cooling, the powder feed nozzle can preferably also have a shielding gas supply arranged on the base body. This additional shielding gas supply allows the working distance between the component to be welded and the powder feed nozzle to be increased without impairing the welding result. The larger working distance also reduces heat generation at the powder feed nozzle. Furthermore, the increased working distance enables welding of hard-to-reach areas. This improves the handling and usability of the powder feed nozzle. The shielding gas supply ensures stable guidance of the powder-gas mixture exiting the outlet of the discharge section over a relatively long distance, thus allowing the working distance of the powder feed nozzle to be extended accordingly.

[0019] The protective gas supply preferably comprises a protective gas supply line extending axially along the main section of the base body, which may be split into several protective gas outlet lines in the region of the outlet section of the base body. Each of these multiple protective gas outlet lines may have a protective gas outlet opening, and the outlet openings of the multiple protective gas outlet lines may be arranged in a ring around the outlet opening of the outlet section. By splitting the system into multiple protective gas outlet lines arranged in a ring around the outlet opening of the outlet section, the powder-gas mixture exiting the outlet opening can be guided through the protective gas in a targeted and controlled manner.The jet of powder-gas mixture exiting the outlet can be supported around its entire circumference by the shielding gas escaping from the shielding gas outlets of the shielding gas lines, so that the powder-gas mixture jet remains stable even after exiting the outlet, until it reaches the component to be welded. This significantly improves the entire welding process.

[0020] To achieve a uniform distribution of the protective gas to the individual protective gas outlet lines, the protective gas supply in the outlet section can be provided with a protective gas distribution line extending radially around the base body, which can be connected to the protective gas outlet lines. The protective gas distribution line preferably connects to the protective gas supply line in the outlet section, allowing the protective gas to flow from the supply line into the distribution line. The distribution line preferably extends in a ring shape around the circumference of the outlet section. The multiple protective gas outlet lines connect to the distribution line, allowing the protective gas to flow from the distribution line into the individual outlet lines.

[0021] The problem according to the invention is further solved by a welding device which has a powder feed nozzle designed and further developed as described above. The welding device can, for example, be designed in the form of a laser welding device in which the surface of a component to be welded is heated by means of a laser beam, thereby forming a weld pool on the component, and a powder-gas mixture can be introduced into the weld pool by means of the powder feed nozzle. Other types of welding devices are also conceivable.

[0022] Further measures improving the invention are described in more detail below, together with a description of a preferred embodiment of the invention, with reference to the following figures.

[0023] They show: Fig. 1 a schematic representation of a powder feed nozzle according to the invention, Fig. 2 a schematic top view of the in Fig. 1 powder feed nozzle shown, Fig. 3 a schematic sectional view of the in Fig. 2 powder feed nozzle shown along line AA, Fig. 4 a schematic sectional view of the exit section of the in Fig. Powder feed nozzle shown in 1 to 3, Fig. 5 a schematic detailed representation of the exit section of the in Fig. Powder feed nozzle shown in 1 to 3, Fig. 6 a schematic representation of a top view of a side view of the in Fig. 5 shown exit section, Fig. 7 a schematic representation of a top view from the front of the in Fig. 5 shown exit section, Fig. 8 another schematic representation of a top view of a side view of the in Fig. 5 shown exit section, and Fig. 9 a schematic sectional view along the in Fig. 8 drawn line B - B.

[0024] Fig. Figure 1 shows a powder feed nozzle 100 according to the invention, by means of which a powder-gas mixture, such as a powder-helium mixture, can be supplied to a welding process.

[0025] The powder feed nozzle 100 has a base body 110, which is divided into a main section 111 and an outlet section 112 adjacent to the main section 111. The powder-gas mixture is guided via the main section 111 to the outlet section 112, with an outlet opening 113 formed at one free end of the outlet section 112. The powder-gas mixture flows out of the powder feed nozzle 100 towards the component to be welded through this outlet opening 113. The outlet opening 113 is located at the end face of the outlet section 113 and thus at the end face of the base body 110. The main section 111 is significantly longer than the outlet section 112. The outlet section 112 is designed such that its outer circumference tapers towards the outlet opening 113.

[0026] The powder feed nozzle 100 features, as is also particularly evident in Fig. 5 and Fig. As can be seen in Figure 6, several coolant pairs 114A, 114B, 114C are present, through which coolant can be guided along the base body 110 to cool the powder feed nozzle 100. Water, for example, can be used as the coolant. Each coolant pair 114A, 114B, 114C forms a separate coolant circuit, with the coolant circuits of the individual coolant pairs 114A, 114B, 114C being separate from each other.

[0027] Each coolant pair 114A, 114B, 114C has a coolant supply line 115A, 115B, 115C, a coolant discharge line 116A, 116B, 116C, and, in the embodiment shown here, three coolant connecting lines 117A, 117B, 117C. The coolant connecting lines 117A, 117B, 117C each connect the coolant supply line 115A, 115B, 115C to the coolant discharge lines 116A, 116B, 116C of a coolant pair 114A, 114B, 114C. The coolant flow in the coolant supply line 115A, 115B, 115C is split into three coolant flows each upon entering the coolant connecting lines 117A, 117B, 117C, whereby these three split coolant flows are recombined upon entering the coolant discharge line 116A, 116B, 116C.

[0028] The coolant supply lines 115A, 115B, 115C and the coolant discharge lines 116A, 116B, 116C each extend axially along the length of the main section 111, with the coolant supply lines 115A, 115B, 115C and the coolant discharge lines 116A, 116B, 116C extending into the outlet section 112. The coolant supply lines 115A, 115B, 115C of the individual coolant pairs 114A, 114B, 114C run parallel to each other.

[0029] The coolant discharge lines 116A, 116B, 116C of the individual coolant pairs 114A, 114B, 114C also run parallel to each other.

[0030] The coolant connecting lines 117A, 117B, 117C, however, extend radially around the outlet section 112, at least in some areas. The coolant connecting lines 117A, 117B, 117C thus encircle the outlet section 112, at least in some areas, in a ring-like manner. The flow direction of the coolant in the coolant connecting lines 117A, 117B, 117C is therefore essentially perpendicular to the flow direction of the coolant in the coolant supply lines 115A, 115B, 115C and the coolant discharge lines 116A, 116B, 116C. The coolant connecting lines 117A, 117B, 117C extend parallel to each other, with the coolant connecting lines 117A, 117B, 117C being arranged side by side in a row.

[0031] In contrast to the coolant supply lines 115A, 115B, 115C and the coolant discharge lines 116A, 116B, 116C, the coolant connection lines 117A, 117B, 117C have a smaller diameter, in particular a smaller flow diameter.

[0032] Furthermore, the coolant connection lines 117A, 117B, 117C do not extend exactly at the angle of the perpendicular axis A to the longitudinal axis L of the base body 110, as shown in Fig. 2 and Fig. 6 is shown, but the coolant connection lines 117A, 117B, 117C each run at an angle of 2° ≤ α ≤ 20° to the perpendicular axis A of the longitudinal axis L of the base body 110. The angle α is approximately 6° in the embodiment shown here.

[0033] The coolant supply lines 115A, 115B, 115C, the coolant discharge lines 116A, 116B, 116C and the coolant connection lines 117A, 117B, 117C are formed in one piece with the base body 110.

[0034] In addition to the coolant guide, the powder feed nozzle 100 features, as particularly in the Fig. 3, Fig. 4, Fig. 7, Fig. 8 and Fig. As can be seen in 9, there is a protective gas supply 118.

[0035] The protective gas supply 118 has a protective gas supply line 119 extending axially along the main section 111. In the area of ​​the outlet section 112, the protective gas supply line 119 opens into a protective gas distribution line 120. The protective gas distribution line 120 extends radially around the base body 110, in particular radially around the outlet section 112 of the base body 110. The protective gas distribution line 120 thus forms a ring shape.

[0036] Several shielding gas outlet lines 121 are connected to the shielding gas distribution line 120, as are found particularly in Fig.Figure 7 shows that each shielding gas outlet line 121 has a shielding gas outlet opening 122 from which the shielding gas can flow towards the component to be welded. The shielding gas outlet openings 122 are arranged in a ring around the outlet opening 113 of the outlet section 112 of the base body 110. By splitting the system into several shielding gas outlet lines 121, which are arranged in a ring around the outlet opening 113 of the outlet section 112, the powder-gas mixture exiting the outlet opening 113 can be guided in a targeted and controlled manner by the shielding gas.The jet of powder-gas mixture exiting the outlet opening 113 can be supported around its entire circumferential area by the shielding gas exiting from the shielding gas outlet openings 122 of the shielding gas outlet lines 121, so that the jet of powder-gas mixture can be kept stable even after it exits the outlet opening 113, until the jet reaches the component to be welded.

[0037] The protective gas outlet openings 122 can be arranged flush with the outlet opening 113 on the front face of the base body 110. Reference symbol list 100 powder feed nozzle 110 basic bodies 111 Main Section 112 Exit section 113 Exit opening 114A, 114B, 114C Coolant pair 115A, 115B, 115C Coolant supply line 116A, 116B, 116C Coolant drain line 117A, 117B, 117C Coolant connection line 118 Shielding gas supply 119 Shielding gas supply line 120 Inert gas distribution line 121 Shielding gas outlet pipe 122 Inert gas outlet L Longitudinal axis A plumb axis α angle

Claims

Powder feed nozzle (100) for a welding device, comprising a base body (110) which has a main section (111) and an outlet section (112) adjoining the main section (111), wherein the outlet section (112) has an outlet opening (113), with at least one coolant supply line (115A, 115B, 115C) extending axially along the main section (111) and with at least one coolant discharge line (116A, 116B, 116C) extending axially along the main section (111), wherein the at least one coolant supply line (115A, 115B, 115C) and the at least one coolant discharge line (116A, 116B, 116C) extend via at least two coolant connecting lines (117A, 117A, 117A) extending radially at least partially around the outlet section (112). 117B, 117C), characterized in that at least two coolant pairs (114A, 114B, 114C) are connected, each with a coolant supply line (115A, 115B, 115C),a coolant discharge line (116A, 116B, 116C) and at least two coolant connection lines (117A, 117B, 117C) are provided, wherein the coolant connection lines (117A, 117B, 117C) of the individual coolant pairs (114A, 114B, 114C) are arranged parallel to each other in a row along at least a region of the length of the outlet section (112). Powder feed nozzle (100) according to claim 1, characterized in that the at least two coolant connection lines (117A, 117B, 117C) have a smaller diameter than the coolant supply line (115A, 115B, 115C) and the coolant discharge line (116A, 116B, 116C). Powder feed nozzle (100) according to one of claims 1 or 2, characterized in that the at least two coolant connection lines (117A, 117B, 117C) each run at an angle of 2° ≤ α ≤ 20° to a perpendicular axis (A) of a longitudinal axis (L) of the base body (110). Powder feed nozzle (100) according to one of claims 1 to 3, characterized by a protective gas supply (118) arranged on the base body (110). Powder feed nozzle (100) according to claim 4, characterized in that the protective gas supply (118) has a protective gas supply line (119) extending axially along the main section (111), which is split into several protective gas outlet lines (121) in the area of ​​the outlet section (112), wherein the several protective gas outlet lines (121) each have a protective gas outlet opening (122), wherein the protective gas outlet openings (122) of the several protective gas outlet lines (121) are arranged in a ring-shaped distribution around the outlet opening (113) of the outlet section (112). Powder feed nozzle (100) according to claim 5, characterized in that the protective gas supply (118) in the area of ​​the outlet section (112) has a protective gas distribution line (120) extending radially around the base body (110), which is connected to the protective gas outlet lines (121). Welding device, with a powder feed nozzle (100) which is designed according to one of claims 1 to 6.

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