Component assembly with fiber laser welded connections and method of manufacturing the same

Abstract

The invention relates to a component assembly comprising a first component (10), a second component (20) and a fiber laser welded connection (2) between the first component (10) and the second component (20) in order to connect the first component with the second component over a joining gap (6), wherein the fiber laser welded connection (2) comprises at least a first weld seam (3) and a second weld seam (4), and wherein the first weld seam (3) and the second weld seam (4) are arranged directly next to each other and in contact with each other. The invention also relates to a method for producing the fiber laser welded connection.

Description

Technical Field

[0001] The present invention relates to a component assembly having a fiber laser welded joint, an injector, particularly a fuel injector having such a component assembly, and a method for manufacturing a fiber laser welded joint. Background Technology

[0002] Welded connections between two components with different configurations are known from existing technology. For example, in the manufacture of a fuel injector, two components, the inner electrode and the connector sleeve, are connected by welding. Here, a single weld seam is created using a disc laser. Due to increasingly stringent environmental standards for internal combustion engines, the injection pressures of both diesel and gasoline internal combustion engines are constantly increasing. Current research has found that, due to pressures exceeding 800 × 10⁻⁶... 5 Extremely high pressures within the Pa range, under vibrational loads, such as those in internal combustion engines used in vehicles, can lead to weld failure due to overload in currently used welded connections. Therefore, improvements to these welded connections are needed, especially in the case of injectors used at very high pressures. Summary of the Invention

[0003] Compared to existing technologies, the component assembly of the present invention has the advantage that the welded connection between the two components exhibits very high strength even under high and difficult conditions. In particular, even under continuous loads, such as in the case of injectors in a vehicle internal combustion engine, weld failure due to vibration loads and high pressure can be avoided. Here, the component assembly includes first and second components and a fiber laser welded connection between the two components. The fiber laser welded connection connects the first component and the second component at the joint gap between the components. Here, the joint gap between the first and second components is the location where the components to be joined are in contact with each other. Here, the fiber laser welded connection includes at least a first weld and a second weld. Here, the at least two welds are arranged directly side by side, wherein the welds are in contact with each other and at least one weld is located at the joint gap between the components to be joined. All welds are fiber laser welds, so that there is an impression of continuous welds after the welds are completed.

[0004] Furthermore, preferred extensions of the present invention are provided.

[0005] Further preferably, the first weld is partially arranged on the joint gap between the first and second components. Particularly preferably, the second weld is arranged on the joint gap between the two components. It should be noted that it is also particularly advantageous that not only the first weld but also the second weld is arranged on the joint gap between the two components. This results in a partial overlap of the first and second welds on the joint gap, wherein the overlap is preferably as small as possible.

[0006] Further preferably, the first and second components are each configured as surrounding closed components, and the fiber laser welding connection is also configured as surrounding closed components. The first and second components are particularly preferably configured as cylindrical, especially hollow cylindrical, mating joints.

[0007] Further preferably, the fiber laser welding connection is constructed on the outer periphery of the cylindrical or hollow cylindrical mating parts.

[0008] According to a further preferred configuration of the invention, in the case of a surrounding closed member, the start and end points of different welds are staggered longitudinally or circumferentially. This avoids the start and end points of different welds being at the same height in the circumferential direction.

[0009] According to a further preferred configuration of the invention, the fiber laser welding connection is arranged such that the penetration between the first and second components is incomplete, particularly in areas less than 90% of the component wall thickness. This incomplete penetration is particularly preferably less than or equal to 80% and greater than or equal to 50% of the component wall thickness.

[0010] Further preferably, the depth-to-width ratio of the weld is chosen to be as large as possible. Here, the depth-to-width ratio is the ratio of the weld depth in the component to the maximum weld width. Here, the maximum weld width is on the surface of the components to be joined. The depth-to-width ratio is preferably greater than 5, and particularly greater than 8.

[0011] According to a further preferred configuration of the invention, the fiber laser connection includes at least one third weld. Here, the welds are positioned such that the second and third welds are arranged directly alongside and in contact with the first weld. Specifically, the second weld contacts a first side of the first weld, and the third weld contacts a second side of the first weld. Preferably, the first weld is centrally located between the second and third welds.

[0012] Furthermore, it should be noted that a fourth weld may preferably be provided, or even more preferably a fifth weld. The arrangement should be selected according to the number of welds on the joint gap of the component. In the case of four welds, the joint gap is arranged between the two middle welds, and the two outer welds contact one of the two middle welds respectively. In the case of five welds, the middle weld is arranged directly on the joint gap of the component, and two additional welds are provided on each side of the middle weld, contacting each other. Thus, even with four or five welds, the impression of a single weld is created.

[0013] Further preferably, the weld widths are chosen to be identical for each weld. This ensures a limited heat input to the components, and all welds can be manufactured using the same fiber laser without altering the laser settings. This ensures that excessive heat input is not introduced into the two components to be joined. Preferably, the weld width on the component surface is in the range of 250-350 μm, particularly preferably in the range of 260-320 μm. Preferably, the gap width at the inner end of the weld is in the range of 70-140 μm, particularly preferably in the range of 80-130 μm. This results in a gradually tapering weld in cross-section. Consequently, the welds contact or overlap each other on the component surface while being spaced apart inside the component. This allows for targeted reduction of heat input to the components to be joined.

[0014] In the case of three welds, it is particularly preferred that the middle weld is centrally located in the joint gap between the two components to be joined. More preferably, when the components have a closed perimeter, such as in the case of cylindrical components to be joined, the start and end points of the welds are staggered circumferentially. Here, the staggering is particularly carried out such that the start and end points are staggered by an angle of 360° divided by the number of welds. For example, in the case of three welds, the start and end points are staggered by an angle of 120° along the perimeter.

[0015] More preferably, when three welds are provided, the first distance between the first centerline of the first weld and the second centerline of the second weld is equal to the second distance between the first centerline of the first weld and the third centerline of the third weld. This achieves a symmetrical arrangement of the second and third welds relative to the first weld. More preferably, the first distance and / or the second distance between the centerlines of the at least three welds are in the range of 20 μm to 100 μm, particularly in the range of 40 μm to 80 μm.

[0016] More preferably, the first and second components are made of metallic material. More preferably, the two mating components have mutually parallel wall regions in the joint gap.

[0017] Furthermore, the present invention relates to an injector, particularly a fuel injector, comprising components according to the invention. Particularly preferably, the injector is an electromagnetic injector, and the first component is the inner pole of the injector, and the second component is a sleeve, particularly a connector sleeve for hydraulic connection of the injector.

[0018] Furthermore, the present invention relates to a method for fabricating a fiber laser welding connection between a first component and a second component. This method includes the following steps: positioning the first and second components for a joining step by means of welding; fabricating a first weld in the region of the joint gap between the first and second components by means of a fiber laser; and fabricating a second weld by means of a fiber laser, the second weld being directly adjacent to a first side of the first weld.

[0019] More preferably, the method further includes the step of manufacturing a third weld. Here, the welds are arranged such that the third weld is directly adjacent to and in contact with the first weld on the second side of the first weld.

[0020] Preferably, a fourth weld is also provided, or more preferably a fifth weld is also provided. Here, these welds are always arranged relative to each other so that after the fiber laser welding connection is completed, it creates the impression of a single seam.

[0021] Preferably, in the case of three weld seams, the first weld seam is manufactured completely first, followed by the second weld seam, and then preferably the third weld seam. However, it should be noted that it is also possible to manufacture the weld seams with overlapping time intervals, for example, starting with the first weld seam, preferably starting the second weld seam after a certain time interval, and finally starting the third weld seam after another certain time interval. However, it is preferred to manufacture the three weld seams sequentially, as this significantly reduces the cost for fiber lasers.

[0022] Preferably, in the case of three welds, the first weld is placed directly on the joint gap between the first and second components. Preferably, the first weld is centrally located on the joint gap. However, it is also preferable to place the first weld slightly offset relative to the joint gap, thus covering it, and then centrally place another weld on the joint gap. That is, in fiber laser bonding welding, one or two outer welds can be placed first, followed by the middle weld.

[0023] More preferably, the fiber laser is vertically aligned with the joint between the first and second components. This allows for precise positioning of the fiber laser weld along the joint.

[0024] Particularly preferably, the start and / or end points of the at least three welds are staggered along the weld direction, especially if the first and second elements are closed members, particularly cylindrical members, and even more particularly hollow cylindrical members.

[0025] More preferably, the laser spot on the surface of the component to be joined is selected such that the laser spot has a diameter in the range of 10 μm to 60 μm, particularly in the range of 15 μm to 40 μm.

[0026] More preferably, in the case of three welds, the welds are arranged such that the centerline of the first weld has a first gap relative to the centerline of the second weld, which is the same as the second gap between the first centerline and the third centerline of the third weld.

[0027] Preferably, the speed used to produce the first, second and third welds is set in the range of 3.0 m / min to 8.0 m / min, especially 4.3 m / min to 5.3 m / min, and particularly about 4.8 m / min.

[0028] It should be further explained that, in order to create a fiber laser welding connection, the fiber laser can be moved, or the two components can be moved, or not only the fiber laser but also the two components can be moved. However, a preferred configuration is one in which the two components are moved, particularly rotated.

[0029] Preferably, the welding process using a fiber laser is performed in a nitrogen atmosphere. More preferably, the first and second components press against each other at the joint with a predetermined force. Preferably, the predetermined force is in the range of 200 Nm to 350 Nm, and more preferably 300 Nm. According to a further preferred configuration of the invention, when the components are closed around the joint, the three welds begin and end with an angular misalignment in the circumferential direction, wherein the angular misalignment is preferably 120°. Attached Figure Description

[0030] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The drawings show:

[0031] Figure 1 A schematic diagram of an injector having a component assembly according to the first embodiment.

[0032] Figure 2 Figure 1 Enlarged detail images of the components, featuring fiber laser welding connections.

[0033] Figure 3 An enlarged view of the component assembly according to the second embodiment of the present invention.

[0034] Figure 4 and 5 Manufactured according to the method of the present invention Figure 3 A schematic diagram of the intermediate steps in fiber laser welding.

[0035] Figure 6 A schematic diagram of a weld used to explain the positioning of the start and end points of the weld according to the second embodiment. Detailed Implementation

[0036] The following is for reference. Figure 1 and 2The component assembly 1 and the method for manufacturing fiber laser welding connections are described in detail according to a preferred embodiment.

[0037] Figure 1 An injector 100 having a longitudinal axis XX is schematically shown, which includes a component assembly 1 according to the invention. Here, the component assembly 1 includes a first component 10 and a second component 20.

[0038] In this embodiment, the first component 10 is the inner pole 10 of the injector 100 and the second component 20 is a connector sleeve, by means of which the hydraulic connection of the injector 100 is realized.

[0039] The injector 100 includes an injection port 101 and an electromagnetic actuator 102, wherein the first component 10 is part of the electromagnetic actuator 102. Additionally, a hydraulic connector 103 and an electrical connector 104 are shown.

[0040] Figure 2 Component assembly 1 is shown in detail. Here, fiber laser welding connection 2 connects the first component 10 and the second component 20. Figure 2 As can be seen in detail, the fiber laser welding connection 2 includes a first weld 3 and a second weld 4.

[0041] Here, two welds 3 and 4 are arranged on the joint gap 6 between the components 10 and 20 to be joined, so as to achieve a secure connection between the components. The first weld 3 is arranged on the joint gap 6 such that it at least partially covers the joint gap 6. Then, a second weld 4 is placed on the first side of the first weld 3. Here, the second weld 4 also partially covers the joint gap 6. Preferably, the first and second welds 3 and 4 are positioned such that the joint gap 6 is precisely centered between the first and second welds 3 and 4.

[0042] Furthermore, the first width B1 of the first weld 3 is the same as the second width B2 of the second weld 4. Here, reference numeral M1 denotes the centerline of the first weld 3 and reference numeral M2 denotes the centerline of the second weld 4. Here, the centerlines M1 and M2 are at the same distance relative to the joint gap 6, so that a symmetrical fiber laser welded connection 2 is obtained with respect to the joint gap 6.

[0043] If further by Figure 2 It can be seen that the depth T of the two welds 3 and 4 is also the same. Here, the depth T of each weld is approximately 50% of the wall thickness W of the cylindrical hollow components 10 and 20 to be connected. Here, the weld gradually tapers along the depth direction. Here, the depth-to-width ratio T relative to the first width B1 or the second width B2 is greater than 5.

[0044] Therefore, it is preferable to generate welds 3 and 4 using a fiber laser with the same set parameters. Here, the fiber laser is preferably vertically aligned with the surfaces of the components 10 and 20 to be connected.

[0045] Here, in order to avoid material buildup when manufacturing the first and second welds 3 and 4, the start and end points of the two welds 3 and 4 are staggered in the circumferential direction. In the case of two welds, the start and end points are preferably arranged 180° apart on the component.

[0046] Here, it is preferable to select the laser spot of the fiber laser such that the laser spot has a diameter of 10 to 60 μm, especially 15 to 40 μm. Here, either the component to be joined is rotated, or the fiber laser is rotated, or both the component and the fiber laser are rotated. Here, the rotation speed is preferably in the range of 3 revolutions per second.

[0047] Preferably, the two components 10 and 20 to be connected to each other are clamped in the clamping device with a pre-clamping force of 300N.

[0048] The following is for reference. Figures 3 to 6 The component components according to the second embodiment of the present invention are described in detail. Here, the same or functionally identical components are indicated by the same reference numerals.

[0049] Unlike the first embodiment, the component assembly 2 of the second embodiment has a total of three welds, namely the first weld 3, the second weld 4 and the third weld 5.

[0050] Here, the first weld 3 is located in the middle between the second weld 4 and the third weld 5. Here, the second and third welds 4 and 5 are directly located next to and in contact with the first weld 3.

[0051] Here, the first width B1 of the first weld 3 is the same as the second width B2 of the second weld 4 and the third width B3 of the third weld 5. Therefore, these welds are constructed with the same width.

[0052] If further, it can be by Figure 3 It can be seen that the depth T of the three welds 3, 4 and 5 is also the same.

[0053] In this embodiment, the first and second components 10 and 20 are also hollow cylindrical components, wherein the depth of each weld 3, 4, 5 is approximately 50% of the wall thickness W of the two components 10 and 20 to be connected to each other.

[0054] Therefore, three welds 3, 4, and 5 are generated using a fiber laser with the same set parameters, forming a fiber laser welded connection 2. Here, the fiber laser is vertically aligned with the surfaces of the components 10 and 20 to be connected to each other.

[0055] If it can be by Figure 3 It can be seen that the first weld 3 is placed directly on the joint gap 6 between the two components 10 and 20. Here, the first weld 3 is centrally located on the joint gap 6.

[0056] Because the two components 10 and 20 to be connected are closed loops, the three welds 3, 4, and 5 are also completely looped around each other. To avoid material buildup or accidental disintegration of the existing welds, the starting and ending points 7 and 8 of the three welds 3, 4, and 5 are staggered circumferentially. Preferably, the starting and ending points 7 and 8 are staggered by 120° each, as shown below. Figure 6 As illustrated in the diagram.

[0057] For the method of the present invention used to manufacture a fiber laser welded connection 2 between a first component 10 and a second component 20, the two components 10 and 20 are first joined together abutting each other, resulting in a joint gap 6. Here, the outer diameter of the first component is the same as the outer diameter of the second component. Then, a first weld 3 is first manufactured, which is directly formed on the joint gap 6, and here it is symmetrically formed on the joint gap 6. In the next step, a second weld 4 is manufactured, wherein the second weld 4 is manufactured directly next to and in contact with the first weld 3. This is in... Figure 5 The explanation is as follows.

[0058] In the next step, a third weld 5 is manufactured, which is located on the second side of the first weld 3, and is also generated directly next to and in contact with the first weld 3. Here, the fiber laser is aligned with the surface of components 10 and 20 at a 90° angle.

[0059] Further preferably, the three welds 3, 4, and 5 are positioned such that the distance (spacing A1) between the first centerline M1 of the first weld and the second centerline M2 of the second weld is the same as the distance A2 between the first centerline M1 and the third centerline M3 of the third weld. Here, the distances A1 and A2 between the centerlines M1, M2, and M3 are preferably in the range of 40 to 80 μm, and particularly preferably about 60 μm.

[0060] Due to the small focal diameter of fiber lasers, welds with very small seam widths and large aspect ratios can be fabricated in the described embodiments. Therefore, higher feed rates can be achieved at the same power compared to other welding systems. This also reduces the maximum lateral deformation of the component. Furthermore, very short process times can be achieved while simultaneously achieving relatively low power requirements and reduced component heating.

[0061] The relatively low power input of the fiber laser does not cause plastic deformation in one or two components 10, 20. Furthermore, the high welding speed of approximately 4.8 m / min reduces the weld width, resulting in a reduction in the so-called "nail head" on the outer region of the weld.

[0062] To connect the two hollow cylindrical components 10 and 20 of the injector 100, the fiber laser is exemplarily configured as follows: maximum power of 320W; laser spot diameter of 25μm; resulting weld with a width of 300μm on the outer side of the components; and a weld with a width of 120μm inside the joined components. The movement speed between the laser and the components is 4.8m / min, and the welding process is performed under nitrogen conditions. The welds begin and end staggered at their starting points. Inspection using a computed tomography scanner confirms the absence of gaps in the fiber laser welded joint. By using a fiber laser, reduced heat input is achieved in the components. This reduction in heat input and minimization of weld deformation results in increased weld strength and reduced residual stress in the weld. This leads to improved weld geometry and the absence of gap formation in the weld between the two components to be joined.

[0063] Therefore, according to the present invention, an efficient and cost-effective connection of two components 10, 20 can be achieved by means of a fiber laser and by setting at least two weld seams. Here, the invention is particularly applicable to connecting two components of an injector, especially connecting a hollow cylindrical inner pole and a hollow cylindrical joint sleeve, wherein the two components have the same outer diameter. Here, despite setting at least two weld seams, the effective welding time can still be significantly reduced compared to the prior art. Thus, significant cost savings can be achieved, especially in the case of manufacturing such batch components (such as injectors). It should be noted that in the case of hollow cylindrical components, the fiber laser welded connection 2 can also be made on the inner circumference of the component.

Claims

1. Components and assemblies, including: - First component (10). - Second component (20), and - Fiber laser welding connection (2) between the first component (10) and the second component (20) to connect the first component and the second component at the joint gap (6), - Wherein, the fiber laser welding connection (2) includes at least a first weld (3) and a second weld (4), and - Wherein, the first weld (3) and the second weld (4) are arranged directly side by side and in contact with each other, wherein the first weld (3) and the second weld (4) gradually taper from the surface of the component to the interior of the component in the cross section, such that the first weld (3) and the second weld (4) are in contact with each other on the surface of the component and are spaced apart from each other inside the component.

2. The component assembly according to claim 1, wherein, The first weld (3) is arranged on the joint gap (6) between the first and second components (10, 20).

3. The component assembly according to claim 1 or 2, wherein, The second weld (4) is arranged on the joint gap (6) between the first and second components (10, 20).

4. The component assembly according to claim 1 or 2, wherein, The first and second components (10, 20) are respectively closed around the perimeter and the fiber laser welding connection (2) is also closed around the perimeter.

5. The component assembly according to claim 1 or 2 further includes a third weld (5), wherein, The second weld (4) and the third weld (5) are arranged to be directly adjacent to and in contact with the first weld (3).

6. The component assembly according to claim 5, wherein, The first weld (3) is centrally located on the joint gap (6) between the first component (10) and the second component (20).

7. The component assembly according to claim 5, wherein, The first spacing (A1) between the first center line (M1) of the first weld (3) and the second center line (M2) of the second weld (4) is the same as the second spacing (A2) between the first center line (M1) and the third center line (M3) of the third weld (5).

8. The component assembly according to claim 1 or 2, wherein, The start and end points of the weld are staggered in the circumferential direction.

9. The component assembly according to claim 1 or 2, wherein, The widths of the welds (B1; B2; B3) are all the same.

10. The component assembly according to claim 1 or 2, wherein, The fiber laser welding connection (2) did not completely penetrate the components (10, 20).

11. The component assembly according to claim 1 or 2, wherein, The width of one of the welds on the surface of the component is in the range of 250 μm to 350 μm.

12. The component assembly according to claim 8, wherein, The start and end points of the weld are offset 360° in the circumferential direction by the number of welds.

13. The component assembly according to claim 11, wherein, The width of one of the welds on the surface of the component is in the range of 260 μm to 320 μm.

14. An injector comprising a component assembly (1) according to any one of the preceding claims.

15. The injector according to claim 14, wherein, The injector is a fuel injector.

16. The injector according to claim 14 or 15, wherein, The first component (10) is the inner pole of the injector and the second component (20) is the sleeve of the injector.

17. The injector according to claim 16, wherein, The sleeve is a connector sleeve.

18. A method for manufacturing a fiber laser welded connection (2) between a first component (10) and a second component (20), comprising the following steps: - The first and second components (10, 20) are positioned such that they abut against each other at the joint gap (6). - A first weld (3) is created between the first and second components in the region of the joint gap (6) using a fiber laser, and - A second weld (4) is manufactured, which is located directly adjacent to and in contact with the first weld (3) on the first side, wherein, The first weld (3) and the second weld (4) gradually taper from the surface of the component to the interior of the component in the cross section, such that the first weld (3) and the second weld (4) are in contact with each other on the surface of the component but are spaced apart from each other inside the component.

19. The method according to claim 18, further comprising the step of: - Create a third weld (5) which is located directly adjacent to the first weld (3) on the second side of the first weld (3) and in contact with the first weld (3).

20. The method according to claim 18 or 19, wherein, The fiber laser is vertically aligned with the surfaces of the first and second components (10, 20) to be joined.

21. The method according to claim 18 or 19, wherein, The start and / or end points of welds (3, 4, 5) are staggered along the longitudinal direction of the weld.

22. The method according to claim 18 or 19, wherein, The first and second components are closed around each other.

23. The method according to claim 22, wherein, The angular misalignment between the start and end points of each weld (3, 4, 5) is 360° divided by the number of welds.

24. The method according to claim 18 or 19, wherein, The laser spot of the fiber laser on the surface of the component to be joined has a diameter in the range of 10 to 60 μm.

25. The method according to claim 24, wherein, The laser spot has a diameter in the range of 15 to 40 μm.

26. The method according to claim 18 or 19, wherein, The welding speed is in the range of 3.0 m / min to 8.0 m / min.

27. The method according to claim 26, wherein, The welding speed is 4.8 m / min.

28. The method according to claim 22, wherein, The surrounding closed component is a cylindrical component.

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