Laser welded shock absorber with enhanced fatigue performance

Abstract

A damper that dampens vibrations of a crankshaft of a vehicle is disclosed. The damper includes a hub having a circular wall extending about an axis of rotation to define a bore formed therethrough. The wall includes a stepped portion extending radially from the wall and having a first arcuate portion formed thereon. The hub includes a main body portion extending radially from the wall to a lip to define an open cavity. The damper further includes an inertia ring disposed in the open cavity to provide inertia of the damper and a plate disposed on the lip of the hub and extending to the step of the wall to enclose the inertia ring in the open cavity. The plate abuts the wall and has a second arcuate portion arranged to cooperate with the first arcuate portion to define a hollow channel disposed radially about the wall of the hub. The damper includes a weld nugget interposed between the hub and the plate. The weld nugget has a root portion extending coincident with the axis of rotation through the hub and the plate to join the hub and the plate. The root portion has a tip defining a profile such that the hollow channel is disposed at an angle tangent to the profile.

Description

Technical Field

[0001] This disclosure relates to shock absorbers for vehicle crankshafts, and more specifically to laser-welded shock absorbers with enhanced fatigue performance. Background Technology

[0002] Shock absorbers used in vehicle crankshafts help reduce internal vibrations, but they are susceptible to high-stress conditions. These conditions can include centrifugal stress on the weld, vibrations that stress the weld, and increased internal temperature, all of which generate bending stress on the weld. Such conditions can lead to cracks in the weld of the shock absorber. Summary of the Invention

[0003] Therefore, while current shock absorbers have achieved their intended purpose, a new and improved system and method are still needed to manufacture laser-welded shock absorbers with enhanced fatigue performance.

[0004] According to one aspect of this disclosure, a shock absorber for suppressing vibrations of a vehicle crankshaft is disclosed. The shock absorber includes a hub with a circular wall extending about an axis of rotation of the shock absorber to define a hole formed therethrough. The wall includes a stepped portion extending radially therefrom, and the stepped portion has a first arcuate portion formed thereon. The hub includes a body portion extending radially from the wall to a lip to define an open cavity. The shock absorber also includes an inertia ring disposed in the open cavity to provide shock absorber inertia.

[0005] In this respect, the shock absorber also includes a plate disposed on the lip of the hub and extending to a step in the wall to enclose the inertial ring in an open cavity. The plate abuts the wall and has a second arcuate portion arranged to mate with a first arcuate portion, thereby defining a hollow channel radially disposed around the wall of the hub.

[0006] The shock absorber also includes a weld nugget formed between the hub and the plate. The weld nugget has a root that extends through the hub and the plate, aligned with the axis of rotation, to connect the hub and the plate. The root extends to a tip that defines a profile, such that the hollow channel is positioned at an angle tangent to the profile to reduce cracking due to stress.

[0007] In one embodiment, the angle of the hollow channel relative to the axis of rotation is between 10° and 50°. In another embodiment, the angle of the hollow channel relative to the axis of rotation is between 15° and 30°. In yet another embodiment, the angle of the hollow channel relative to the axis of rotation is between 20° and 25°.

[0008] In one embodiment, the hollow channel has an elliptical cross-section. In another embodiment, the hollow channel has a circular cross-section. In yet another embodiment, the hollow channel has a rectangular cross-section.

[0009] In another aspect of this disclosure, a method for manufacturing a laser-welded damper with enhanced fatigue performance is provided. The method includes: providing a hub with a circular wall extending about a rotational axis of the damper to define a hole formed therethrough. The wall has a first mating surface and includes a stepped portion extending radially therefrom. The step has a first arcuate portion formed thereon. The hub includes a body portion extending radially from the wall to a lip to define an open cavity.

[0010] The method further includes providing an inertia ring disposed within an open cavity to provide damper inertia. The method also includes providing a plate disposed on a lip of the hub and extending into a step of the wall to enclose the inertia ring within the open cavity. The plate has a second mating surface and abuts a first mating surface of the wall. The plate has a second arcuate portion arranged to mate with the first arcuate portion, thereby defining a hollow channel radially disposed around the wall of the hub.

[0011] In this aspect, the method further includes arranging the wall and plate such that the first and second mating surfaces are in abutment contact. Moreover, the method further includes guiding a laser beam onto the outer surface of the hub, thereby effectively forming a weld nugget positioned between the hub and the plate. The weld nugget has a root extending congruently to the axis of rotation through the hub and the plate to connect the hub and the plate. The root has a pointed tip defining a profile such that the hollow channel is positioned at an angle tangential to the profile to reduce cracking due to stress and stress concentration.

[0012] In one example, the angle of the hollow channel relative to the axis of rotation is between 10° and 50°. The angle can also be between 15° and 30°. In another embodiment, the angle is between 20° and 25°.

[0013] In one example, the hollow channel has an elliptical cross-section. In another example, the hollow channel has a circular cross-section. In yet another example, the hollow channel has a rectangular cross-section.

[0014] In another aspect of this disclosure, a shock absorber is provided for suppressing vibrations of a vehicle crankshaft. The shock absorber includes a hub with a circular wall extending about an axis of rotation of the shock absorber to define a hole formed therein. The wall includes a stepped portion extending radially therefrom, and the stepped portion has a first arcuate portion formed thereon. The hub includes a body portion extending radially from the wall to a lip to define an open cavity.

[0015] In this respect, the shock absorber also includes an inertia ring disposed in an open cavity to provide the inertia of the shock absorber. The shock absorber also includes a plate disposed on the lip of the hub and extending to a step of the wall to enclose the inertia ring in the open cavity. The plate abuts the wall and has a second arcuate portion arranged to mate with a first arcuate portion, thereby defining a hollow channel radially disposed around the wall of the hub.

[0016] In addition, the shock absorber includes a weld nugget positioned between the hub and the plate. The weld nugget has a root that extends parallel to the axis of rotation through the hub and the plate to connect them. The root has a pointed tip defining a profile, such that the hollow channel is positioned at an angle tangent to the profile to reduce cracking due to stress and stress concentration. The angle of the hollow channel relative to the axis of rotation is between 10° and 50°.

[0017] In one embodiment, the angle of the hollow channel relative to the axis of rotation is between 15° and 30°. In another embodiment, the angle of the hollow channel relative to the axis of rotation is between 20° and 25°.

[0018] In one embodiment, the hollow channel has an elliptical cross-section. In another embodiment, the hollow channel has a circular cross-section. In yet another embodiment, the hollow channel has a rectangular cross-section.

[0019] 1. A shock absorber for suppressing crankshaft vibration in a vehicle, the shock absorber comprising:

[0020] A hub having a circular wall extending about the rotation axis of the shock absorber to define a hole formed therein, the wall including a stepped portion extending radially from the wall and having a first arcuate portion formed thereon, the hub including a body portion extending radially from the wall to a lip to define an open cavity;

[0021] An inertial ring is provided in the open cavity to provide the inertia of the shock absorber;

[0022] A plate disposed on the lip of the hub and extending to the step of the wall to enclose the inertial ring in the open cavity, the plate abutting the wall and having a second arcuate portion arranged to mate with the first arcuate portion, thereby defining a hollow channel radially disposed around the wall of the hub; and

[0023] A weld nugget is placed between the hub and the plate, the weld nugget having a root that extends coherently with the axis of rotation through the hub and the plate to connect the hub and the plate, the root having a pointed tip that defines a profile such that the hollow channel is positioned at an angle tangent to the profile to reduce cracking due to stress.

[0024] 2. The shock absorber according to Scheme 1, wherein the angle of the hollow channel relative to the axis of rotation is between 10° and 50°.

[0025] 3. The shock absorber according to Scheme 1, wherein the angle of the hollow channel relative to the axis of rotation is between 15° and 30°.

[0026] 4. The shock absorber according to Scheme 1, wherein the angle of the hollow channel relative to the axis of rotation is between 20° and 25°, and wherein the shock absorber comprises an aluminum alloy.

[0027] 5. The shock absorber according to Scheme 1, wherein the weld nugget extends into the shock absorber to 5 mm to 6 mm and has a weld top width of 2 mm to 3 mm.

[0028] 6. The shock absorber according to Scheme 1, wherein the weld nugget has a depth-to-width ratio of 2 to 3.

[0029] 7. The shock absorber according to Scheme 1, wherein the cross-section of the hollow channel has a diameter between 0.8 mm and 1.5 mm.

[0030] 8. A method for manufacturing a laser-welded vibration damper with enhanced fatigue performance, the method comprising:

[0031] A hub is provided with a circular wall extending about the rotation axis of the shock absorber to define a hole formed therein, the wall having a first mating surface and including a stepped portion extending radially therefrom, the step having a first arcuate portion formed thereon, the hub including a body portion extending radially from the wall to a lip to define an open cavity;

[0032] An inertial ring is provided within the open cavity to provide the inertia of the shock absorber;

[0033] A plate is provided, the plate being disposed on the lip of the hub and extending to the step of the wall to enclose the inertial ring in the open cavity, the plate having a second mating surface and abutting the first mating surface of the wall, the plate having a second arcuate portion arranged to mate with the first arcuate portion, thereby defining a hollow channel radially disposed around the wall of the hub;

[0034] The wall and the plate are arranged such that the first mating surface and the second mating surface are in adjacent contact; and

[0035] A laser beam is guided onto the outer surface of the hub to effectively form a weld nugget positioned between the hub and the plate. The weld nugget has a root that extends coherently with the axis of rotation through the hub and the plate to connect them. The root has a pointed tip that defines a profile such that the hollow channel is positioned at an angle tangent to the profile to reduce cracking due to stress concentration.

[0036] 9. The method according to Scheme 8, wherein the angle of the hollow channel relative to the rotation axis is between 10° and 50°.

[0037] 10. The method according to Scheme 8, wherein the angle of the hollow channel relative to the axis of rotation is between 15° and 30°.

[0038] 11. The method according to Scheme 8, wherein the angle of the hollow channel relative to the axis of rotation is between 20° and 25°.

[0039] 12. The method according to Scheme 8, wherein the hollow channel has an elliptical cross-section.

[0040] 13. The method according to Scheme 8, wherein the hollow channel has a circular cross-section.

[0041] 14. The method according to Scheme 8, wherein the laser beam is set to 600 J / cm to 800 J / cm and has a welding speed of 1.5 m / min to 3.0 m / min and an electron beam spot with a diameter of 0.1 mm to 0.2 mm.

[0042] 15. A shock absorber for suppressing crankshaft vibration in a vehicle, the shock absorber comprising:

[0043] A hub having a circular wall extending about the rotation axis of the shock absorber to define a hole formed therein, the wall including a stepped portion extending radially from the wall and having a first arcuate portion formed thereon, the hub including a body portion extending radially from the wall to a lip to define an open cavity;

[0044] An inertial ring is provided in the open cavity to provide the inertia of the shock absorber;

[0045] A plate disposed on the lip of the hub and extending to the step of the wall to enclose the inertial ring in the open cavity, the plate abutting the wall and having a second arcuate portion arranged to mate with the first arcuate portion, thereby defining a hollow channel radially disposed around the wall of the hub; and

[0046] A weld nugget is placed between the hub and the plate, the weld nugget having a root that extends coherently with the axis of rotation through the hub and the plate to connect the hub and the plate, the root having a pointed tip defining a profile such that the hollow channel is set at an angle tangent to the profile to reduce cracking due to stress, the angle of the hollow channel relative to the axis of rotation being between 10° and 50°.

[0047] 16. The shock absorber according to Scheme 15, wherein the angle of the hollow channel relative to the axis of rotation is between 15° and 30°.

[0048] 17. The shock absorber according to Scheme 15, wherein the angle of the hollow channel relative to the axis of rotation is between 20° and 25°.

[0049] 18. The shock absorber according to Scheme 15, wherein the hollow channel has an elliptical cross-section.

[0050] 19. The shock absorber according to Scheme 15, wherein the hollow channel has a circular cross-section.

[0051] 20. The shock absorber according to Scheme 15, wherein the cross-section of the hollow channel has a diameter between 0.8 mm and 1.5 mm.

[0052] Other application areas will become apparent from the descriptions provided herein. It should be understood that the descriptions and specific examples are intended for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0053] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of this disclosure in any way.

[0054] Figure 1 This is a plan view or top view of a laser-welded shock absorber with enhanced fatigue according to an embodiment of the present disclosure.

[0055] Figure 2 yes Figure 1 A perspective view of the shock absorber.

[0056] Figure 3 It is a section taken along line 3-3. Figure 2 A partial cross-sectional side view of the shock absorber in the image.

[0057] Figure 4 yes Figure 3 An enlarged view of the shock absorber.

[0058] Figure 5Laser welding according to an example of this disclosure Figure 1 The flowchart shows the method for making a shock absorber.

[0059] Figure 6 This is a partial cross-sectional side view of a shock absorber prior to laser welding, according to an embodiment of the present disclosure.

[0060] Figure 7 This is an example of a method for use according to this disclosure. Figure 5 Laser welding method Figure 1 A schematic diagram of the shock absorber system. Detailed Implementation

[0061] The following description is exemplary in nature and is not intended to limit this disclosure, its application or use.

[0062] This disclosure provides a laser-welded damper with enhanced fatigue performance. The damper includes a hollow channel formed radially around the weld root and positioned at a tangential angle to the root. High stresses that would otherwise exist on the weld are transferred to the base metal of the damper, thereby reducing stress concentration on the weld. Therefore, the fatigue life of the damper is improved, and the damper maintains enhanced weld integrity.

[0063] Figures 1-2 A shock absorber 10 for suppressing vibrations of a vehicle crankshaft according to one embodiment of the present disclosure is shown. As shown, the shock absorber 10 includes a hub 12 having a circular wall 14 extending about the axis of rotation of the shock absorber 10 to define a hole 16 formed therein. In operation, the hole 16 will mate with the front end of the vehicle crankshaft. As can be seen, the axis of rotation defines the centerline of the shock absorber 10. Moreover, the circular wall 14 includes a stepped portion 20 extending radially therefrom, and the stepped portion 20 has a first arcuate portion 22 formed thereon. As shown, the hub 12 also includes a body portion 24 extending radially from the circular wall 14 to a lip 30, thereby defining an open cavity 32. In one embodiment, the hub comprises an aluminum alloy, some of which are known mixtures, such as AA2000, 4000, 6000, and 7000 in the T6 tempered state. Such alloys are selected for high strength, wear resistance, and weldability.

[0064] The shock absorber 10 also includes an inertia ring 34 disposed in the open cavity 32 to provide shock absorber inertia. (Reference) Figures 1-3The shock absorber 10 also includes a cover plate 40 disposed on the lip 30 of the hub 12 and extending to the step 20 of the wall 14 to enclose the inertia ring 34 in an open cavity 32. As shown, the plate 40 abuts the wall 14 and has a second arcuate portion 42 arranged to mate with a first arcuate portion 22, thereby defining a hollow channel 44 radially disposed around the wall 14 of the hub 12.

[0065] The cover plate may comprise aluminum alloys, some of which are known mixtures such as AA4000, AA5000, and AA6000. Such alloys can be heat-treated or cold-worked to achieve high weld strength and weldability potential. Furthermore, the inertia ring may comprise cast or forged aluminum alloys. Additionally, adhesive silicone resin may be used to fill the remaining portion of the cavity.

[0066] The shock absorber 10 also includes a weld nugget 50 preferably formed between the hub 12 and the plate 40 by laser welding (discussed below). Also shown, the shock absorber includes a weld nugget 50' formed through the plate 40 and extending to the lip 32. The weld nugget 50 has a root 52 extending into and between the wall 14 and the cover plate 40. As shown, the weld nugget 50 extends coaxially with the axis of rotation to connect the hub 12 and the plate 40. The root 52 extends to a tip 54 defining a profile 60, such that the hollow channel 44 is positioned at an angle tangential to the profile 60 to reduce cracking due to stress.

[0067] When set at an angle tangential to the profile, the hollow channel 44 provides enhanced fatigue performance for the damper 10. That is, high stresses that would otherwise be present on the weld 50 are transferred to the base metal, such as the hub 12 or plate 40. Therefore, stress concentration on the weld 50 is reduced to suppress early fatigue crack formation and thus increase the fatigue life of the damper 10. Additionally, the hollow channel 44 acts as a reservoir for welding gases, improving weld integrity and reducing the detrimental effects of porosity that would otherwise lead to a deteriorated weld fatigue life.

[0068] like Figure 4 As shown, the hollow channel 44 is arranged at an angle tangent to the profile 60 relative to the centerline. In this embodiment, the angle of the hollow channel 44 relative to the centerline is between 10° and 50°. Preferably, the angle of the hollow channel 44 relative to the axis of rotation is between 15° and 30°. More preferably, the angle of the hollow channel 44 relative to the axis of rotation is between 20° and 25°.

[0069] Additionally, the hollow channel 44 is shown as having an elliptical cross-section. In another embodiment, the cross-section of the hollow channel 44 has a circular, rectangular, or any other suitable shape without departing from the scope or spirit of this disclosure.

[0070] Furthermore, when the shape is circular, the diameter of the channel can be between 0.8 mm and 1.5 mm. Conversely, when the shape is elliptical, the major and minor axes of the channel can be between 0.8 mm and 1.5 mm.

[0071] Figure 5 The invention describes an example of manufacturing a material with enhanced fatigue properties according to this disclosure. Figures 1-4 A flowchart of the method 110 for laser welding vibration damper 10. (See attached flowchart.) Figure 5 and Figure 6 As shown, method 110 includes providing a hub 212 with a circular wall 214 in a frame 112, the circular wall 214 extending about the axis of rotation of the shock absorber 10 to define a hole 216 formed therein. The wall 214 has a first mating surface 215 and includes a stepped portion 220 extending radially therefrom. The stepped portion 220 has a first arcuate portion 222 formed thereon. The hub 212 includes a body portion 224 that extends radially from the wall 214 to a lip 230 to define an open cavity 232. In one example, the hub 212 comprises an aluminum alloy, some of which are known mixtures, such as AA2000, 4000, 6000, and 7000 in the T6 tempered state. Such alloys are selected for sufficiently high strength, low residual stress conditions, wear resistance, and weldability.

[0072] In this example, method 110 further includes providing an inertia ring 234 disposed in the open cavity 232 within frame 114 to provide damper inertia. Method 110 also includes providing a plate 240 in frame 120, which is disposed on the lip 230 of hub 212 and extends to a step 220 of wall 214 to enclose the inertia ring 234 in the open cavity 232. As shown, plate 240 has a second mating surface 241 and is positioned to abut (see below) a first mating surface 215 of the wall. Plate 240 has a second arcuate portion 242 arranged to mate with the first arcuate portion 222 (see below) thereby defining a hollow channel 244 radially disposed around the wall 214 of hub 212.

[0073] The cover plate 240 may comprise an aluminum alloy, some of which are known mixtures such as AA4000, AA5000, and AA6000. Such alloys may be heat-treated or cold-worked to achieve the strength and weldability of the base material or matrix, and especially to maintain high weld strength. Furthermore, the inertia ring may comprise a cast or forged aluminum alloy. Additionally, adhesive silicone resin may be used to fill the remaining portion of the cavity.

[0074] like Figure 5As shown, method 110 also includes arranging or moving the wall 214 and plate 240 in frame 122 such that the first and second mating surfaces 215, 241 are in abutment contact. The arrangement step can be achieved by holding the hub in place using any suitable stationary clamp and setting the plate on the lip and stepped portions using a movable robotic arm such that the plate abuts the wall to define a hollow passage.

[0075] Furthermore, method 110 also includes guiding the laser beam within frame 124 onto the outer surface 243 of hub 212, thereby effectively forming a weld nugget positioned between hub and plate (see [link to method 110]). Figure 3 As discussed above, the weld nugget has a root that extends coaxially with the axis of rotation through the hub and the plate to connect the hub and the plate. The root has a pointed tip that defines a profile, such that the hollow channel is positioned at an angle tangent to the profile to reduce cracking due to stress concentration.

[0076] As mentioned above, and as... Figures 3-4 As shown, the hollow channel is arranged tangent to the profile at an angle relative to the centerline. In one example, the angle of the hollow channel relative to the centerline or axis of rotation is between 10° and 50°. In another embodiment, the angle of the hollow channel relative to the centerline is between 15° and 30°. In yet another embodiment, the angle of the hollow channel relative to the centerline is between 20° and 25°.

[0077] In one example, the cross-section of the hollow channel may have an elliptical shape, as shown in the previous figures. However, the cross-section of the hollow channel may have a circular shape, a rectangular shape, or any other suitable shape without departing from the scope or spirit of this disclosure.

[0078] In this example, the laser beam can be a single laser beam from a fiber laser source. In one example, the power output of the laser beam can be 3 kW to 7 kW, and preferably 5-6 kW. The laser beam can have a welding speed of 3 m / min to 6 m / min, and preferably 5-6 m / min. Moreover, the laser beam can have a spot size of 100 micrometers to 200 micrometers, a focal position at 0 mm, and preferably argon gas protection.

[0079] In another example, laser welding can be accomplished using electron beam welding with a power setting of 600 J / cm to 800 J / cm, a welding speed of 1.5 m / min to 3.0 m / min, and an electron beam spot size of 0.1 mm to 0.2 mm. Other laser welding methods and systems, such as fusion welding, can be used without departing from the spirit or scope of this disclosure. In this example, it should be understood that the laser weld nugget can penetrate or extend into the damper by 5 mm to 6 mm, exceeding the thickness of the cover plate, and can have a weld top width of 2 mm to 3 mm. Additionally, the weld can have a depth-to-width ratio of 2 to 3.

[0080] Figure 7 This illustrates the method 110 used to manufacture a laser-welded shock absorber 10 (using the method discussed above). Figures 1-4 A schematic diagram of system 310. System 310 includes a shock absorber to be laser welded, such as... Figure 6 The shock absorber 210 includes a hub with a circular wall extending about the axis of rotation of the shock absorber to define a hole formed therein. The wall has a first mating surface and includes a stepped portion extending radially therefrom. The step has a first arcuate portion formed thereon. The hub includes a body portion extending radially from the wall to a lip to define an open cavity. In one embodiment, the hub comprises an aluminum alloy, some of which are known mixtures, such as AA2000, 4000, 6000, and 7000 in the T6 tempered state. Such alloys are selected for strength, wear resistance, and weldability.

[0081] The shock absorber also includes an inertia ring disposed within an open cavity to provide shock absorber inertia. The shock absorber also includes a plate disposed on the lip of the hub and extending into a stepped section of the wall to enclose the inertia ring within the open cavity. The plate has a second mating surface and abuts a first mating surface of the wall. The plate has a second arcuate portion arranged to mate with the first arcuate portion, thereby defining a hollow channel radially disposed around the wall of the hub.

[0082] The cover plate may comprise aluminum alloys, some of which are known mixtures such as AA4000, AA5000, and AA6000. Such alloys may be heat-treated or cold-worked to achieve strength and weldability. Furthermore, the inertia ring may comprise cast or forged aluminum alloys. Additionally, adhesive silicone resin may be used to fill the remaining portion of the cavity.

[0083] like Figure 7As shown, system 310 also includes a stationary unit 312, which is arranged or configured to arrange the walls and plates such that the first and second mating surfaces are in abutment contact. In one embodiment, the stationary unit 312 may be any suitable stationary stage equipped to receive and hold the hub and plate in place for laser welding. It should be understood that a movable robotic arm 314 or any other suitable movable unit may be used in conjunction with the stationary unit to arrange the walls and plates such that the first and second mating surfaces are in abutment contact.

[0084] Furthermore, system 310 also includes a laser unit 316 to guide a laser beam 318 onto the outer surface of the hub, thereby effectively forming a weld nugget positioned between the hub and the plate. In one embodiment, laser unit 316 may include a laser tool 320 arranged to emit a laser beam onto the outer surface of the hub to effectively form a weld nugget positioned between the hub and the plate. Figure 4 As in the example, the weld nugget has a root that extends into the hub and plate along the axis of rotation to connect them. The root has a pointed tip that defines the profile, such that the hollow channel is positioned at an angle tangent to the profile to reduce cracking due to stress.

[0085] In one example, the angle of the hollow channel relative to the axis of rotation is between 10° and 50°. In another example, the angle of the hollow channel relative to the axis of rotation is between 15° and 30°. In yet another embodiment, the angle of the hollow channel relative to the axis of rotation is between 20° and 25°.

[0086] The laser beam can be a single laser beam from a fiber laser source. In one example, the power output of the laser beam can be 3 kW to 7 kW, and preferably 5-6 kW. The laser beam can have a welding speed of 3 m / min to 6 m / min, and preferably 5-6 m / min. Moreover, the laser beam can have a spot size of 100 micrometers to 200 micrometers, a focal position at 0 mm, and preferably argon gas protection.

[0087] In another example, laser welding can be accomplished using electron beam welding with a power setting of 600 J / cm to 800 J / cm, a welding speed of 1.5 m / min to 3.0 m / min, and an electron beam spot size of 0.1 mm to 0.2 mm. Other laser welding methods and systems, such as fusion welding, can be used without departing from the spirit or scope of this disclosure. In this example, it should be understood that the laser weld nugget can penetrate or extend into the damper by 5 mm to 6 mm, exceeding the thickness of the cover plate, and can have a weld top width of 2 mm to 3 mm. Additionally, the weld can have a depth-to-width ratio of 2 to 3.

[0088] In yet another example, the laser tool is a YAG solid-state laser with a laser spot size of 4 mm, a power of 4800 W, a laser beam velocity of 900 mm / s, and a curing temperature of 1020°C. It should be understood that other laser tools may be used without departing from the spirit or scope of this disclosure.

[0089] refer to Figure 7 The system 310 also includes a controller 322 that communicates with the stationary unit 312, the robotic arm 314, and the laser unit 316. The controller 322 is configured to control the stationary unit 312, the robotic arm 314, and the laser unit 316. Furthermore, the system 310 includes a power supply 324 configured to supply power to the controller 322, the stationary unit 312, the robotic arm 314, and the laser unit 316.

[0090] The description in this disclosure is merely exemplary in nature, and variations thereof that do not depart from the spirit and scope of this disclosure are intended to fall within its scope. Such variations should not be considered as departing from the spirit and scope of this disclosure.

Claims

1. A shock absorber for suppressing crankshaft vibration in a vehicle, the shock absorber comprising: A hub having a circular wall extending about the rotation axis of the shock absorber to define a hole formed therein, the circular wall including a stepped portion extending radially from the circular wall and having a first arcuate portion formed thereon, the hub including a body portion extending radially from the circular wall to a lip to define an open cavity; An inertial ring is provided in the open cavity to provide the inertia of the shock absorber; A plate, which is disposed on the lip of the hub and extends to the stepped portion of the circular wall to enclose the inertial ring in the open cavity, the plate being adjacent to the circular wall and having a second arcuate portion arranged to mate with the first arcuate portion, thereby defining a hollow channel radially disposed around the circular wall of the hub; as well as A weld nugget is placed between the hub and the plate, the weld nugget having a root that extends coherently with the axis of rotation through the hub and the plate to connect the hub and the plate, the root having a pointed tip that defines a profile such that the hollow channel is positioned at an angle tangent to the profile to reduce cracking due to stress.

2. The shock absorber of claim 1, wherein, The hollow channel is at an angle between 20° and 25° relative to the axis of rotation, and the shock absorber comprises an aluminum alloy.

3. The shock absorber of claim 1, wherein, The weld nugget extends into the shock absorber to 5 mm to 6 mm and has a weld top width of 2 mm to 3 mm.

4. The shock absorber of claim 1, wherein, The weld nugget has a depth-to-width ratio of 2 to 3.

5. The shock absorber of claim 1, wherein, The hollow channel has a cross-section with a diameter between 0.8 mm and 1.5 mm.

6. A method for manufacturing a laser-welded vibration damper with enhanced fatigue performance, the method comprising: A hub is provided with a circular wall extending about the rotation axis of the shock absorber to define a hole formed therein, the circular wall having a first mating surface and including a stepped portion extending radially therefrom, the stepped portion having a first arcuate portion formed thereon, the hub including a body portion extending radially from the circular wall to a lip to define an open cavity; An inertial ring is provided within the open cavity to provide the inertia of the shock absorber; A plate is provided, the plate being disposed on the lip of the hub and extending to the stepped portion of the circular wall to enclose the inertial ring in the open cavity, the plate having a second mating surface and abutting the first mating surface of the circular wall, the plate having a second arcuate portion arranged to mate with the first arcuate portion, thereby defining a hollow channel radially disposed around the circular wall of the hub; The circular wall and the plate are arranged such that the first mating surface and the second mating surface are in adjacent contact; as well as A laser beam is guided onto the outer surface of the hub to effectively form a weld nugget positioned between the hub and the plate. The weld nugget has a root that extends coherently with the axis of rotation through the hub and the plate to connect them. The root has a pointed tip that defines a profile such that the hollow channel is positioned at an angle tangent to the profile to reduce cracking due to stress concentration.

7. The method of claim 6, wherein, The angle of the hollow channel relative to the axis of rotation is between 10° and 50°.

8. The method of claim 6, wherein, The angle of the hollow channel relative to the axis of rotation is between 15° and 30°.

9. The method of claim 6, wherein, The angle of the hollow channel relative to the axis of rotation is between 20° and 25°.

10. The method of claim 6, wherein, The hollow channel has an elliptical cross-section.

11. The method of claim 6, wherein, The hollow channel has a circular cross-section.

12. The method of claim 6, wherein, The laser beam is set to 600 J / cm to 800 J / cm and has a welding speed of 1.5 m / min to 3.0 m / min and an electron beam spot with a diameter of 0.1 mm to 0.2 mm.

13. A shock absorber for suppressing crankshaft vibrations in a vehicle, the shock absorber comprising: A hub having a circular wall extending about the rotation axis of the shock absorber to define a hole formed therein, the circular wall including a stepped portion extending radially from the circular wall and having a first arcuate portion formed thereon, the hub including a body portion extending radially from the circular wall to a lip to define an open cavity; An inertial ring is provided in the open cavity to provide the inertia of the shock absorber; A plate, which is disposed on the lip of the hub and extends to the stepped portion of the circular wall to enclose the inertial ring in the open cavity, the plate being adjacent to the circular wall and having a second arcuate portion arranged to mate with the first arcuate portion, thereby defining a hollow channel radially disposed around the circular wall of the hub; as well as A weld nugget is placed between the hub and the plate, the weld nugget having a root that extends coherently with the axis of rotation through the hub and the plate to connect the hub and the plate, the root having a pointed tip defining a profile such that the hollow channel is set at an angle tangent to the profile to reduce cracking due to stress, the angle of the hollow channel relative to the axis of rotation being between 10° and 50°.

14. The shock absorber of claim 13 wherein, The angle of the hollow channel relative to the axis of rotation is between 15° and 30°.

15. The shock absorber of claim 13 wherein, The angle of the hollow channel relative to the axis of rotation is between 20° and 25°.

16. The shock absorber of claim 13, wherein, The hollow channel has an elliptical cross-section.

17. The shock absorber of claim 13 wherein, The hollow channel has a circular cross-section.

18. The shock absorber of claim 13, wherein, The hollow channel has a cross-section with a diameter between 0.8 mm and 1.5 mm.

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