Welded joint for a bicycle frame and method for welding a bicycle frame
The defined weld joint structure addresses weld-related issues in bicycle frames by ensuring consistent quality and reduced stress, enhancing strength and fatigue life while allowing for thinner, lighter tubes with improved design freedom.
Patent Information
- Application Number
- DE102013019176
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- Priority Date
- 2012-11-26
- Filing Date
- 2013-11-18
- Publication Date
- 2025-07-31
- Estimated Expiration
- 2033-11-18
AI Technical Summary
Welds between the upper and lower tubes of a bicycle frame are prone to cracking and separation, leading to stress concentration, inconsistent performance, and reduced fatigue life due to variability in weld quality and residual stress, which is dependent on the skill of the welder.
A defined weld joint structure with machined weld areas that reduce separation and residual stress, allowing for consistent weld quality and thinner, lighter tubes without compromising strength, by ensuring a constant welding angle and surface contact.
The improved weld joint structure enhances the strength and fatigue life of the frame, reduces variability, and allows for design flexibility, resulting in a more aesthetically pleasing and structurally sound bicycle frame.
Smart Images
Figure 00000000_0000_ABST
Abstract
Claims
[1] A bicycle comprising an upper tube (40, 140, 240, 340, 440, 540, 640, 740) having a first tube part (141) and a first weld region (150, 250, 350, 450, 550, 750), wherein the first tube part (141) has a first tube part thickness (148) and the first weld region (150, 250, 350, 450, 550, 750) has a first thickness in the weld region (151), wherein the first weld region (150, 250, 350, 450, 550, 750) has a first joining surface (154, 254), an outer edge (156) and a side wall (152), wherein the side wall (152) extends from the upper tube (40, 140, 240, 340, 440, 540, 640, 740) sticks out; a lower tube (50, 120, 220, 320, 420, 520, 620, 720) having a second tube part (121) and a second welding area (130, 230, 330, 430, 530, 730), wherein the second tube part (121) has a second tube part thickness (128) and the second welding area (130, 230, 330, 430, 530, 730) has a second thickness in the welding area (131), wherein the second welding area (130, 230, 330, 430, 530, 730) has a second connecting surface (134, 234), an outer edge (136) and a side wall (132), wherein the first connecting surface (154, 254) is the second joining surface (134, 234) is arranged adjacent to the first joining surface (134, 234) such that a weld joint (170, 370, 570) is formed between the first welding region (150, 250, 350, 450, 550, 750) and the second welding region (130, 230, 330, 430, 530, 730) at a connection point between the outer edge (156) and the outer edge (136); a weld bead formed along the weld joint (170, 370, 570) connecting the first weld region (150, 250, 350, 450, 550, 750) and the second weld region (130, 230, 330, 430, 530, 730); and wherein the combined thickness of the first thickness in the weld region (151) and the second thickness in the weld region (131) is at least 1 mm. [2] The bicycle according to claim 1, wherein the first welding area (150, 250, 350, 450, 550, 750) and the second welding area (130, 230, 330, 430, 530, 730) are substantially triangular. [3] The bicycle according to claim 1, wherein the first welding area (150, 250, 350, 450, 550, 750) is integrated into the upper tube (40, 140, 240, 340, 440, 540, 640, 740). [4] The bicycle according to claim 1, wherein the second welding area (130, 230, 330, 430, 530, 730) is integrated into the lower tube (50, 120, 220, 320, 420, 520, 620, 720). [5] The bicycle according to claim 1, wherein the first thickness in the welding area (151) is less than the first tube part thickness (148). [6] The bicycle according to claim 1, wherein the second thickness in the welding area (131) is greater than the second tube part thickness (128). [7] The bicycle according to claim 1, wherein the first thickness in the weld area (151) is substantially the same as the first tube part thickness (148). [8] The bicycle according to claim 1, wherein the second thickness in the weld area (131) is substantially the same as the second tube part thickness (128). [9] The bicycle according to claim 1, wherein the second tube part thickness (128) is greater than the first tube part thickness (148). [10] The bicycle according to claim 1, wherein the welding angle (θ) is greater than 90°. [11] The bicycle according to claim 1, wherein the weld bead is not in contact with the first tube part (141) and the second tube part (121) at the same time. [12] The bicycle according to claim 1, wherein the first welding area (150, 250, 350, 450, 550, 750) has substantially the same shape as the second welding area (130, 230, 330, 430, 530, 730). [13] The bicycle according to claim 1, wherein the weld joint (170, 370, 570) defines a weld angle (θ) that is substantially constant along the length of the weld joint (170, 370, 570). [14] The bicycle according to claim 1, wherein the combined thickness of the first thickness in the welding area (151) and the second thickness in the welding area (131) is 12 mm. [15] A bicycle comprising an upper tube (40, 140, 240, 340, 440, 540, 640, 740) having a first tube part (141) and a first weld region (150, 250, 350, 450, 550, 750), wherein the first tube part (141) has a first tube part thickness (148) and the first weld region (150, 250, 350, 450, 550, 750) has a first thickness in the weld region (151), wherein the first weld region (150, 250, 350, 450, 550, 750) has a first joining surface (154, 254), an outer edge (156) and a side wall (152), wherein the side wall (152) extends from the upper tube (40, 140, 240, 340, 440, 540, 640, 740) sticks out; a lower tube (50, 120, 220, 320, 420, 520, 620, 720) having a second tube part (121) and a second welding region (130, 230, 330, 430, 530, 730), wherein the second tube part (121) has a second tube part thickness (128) and the second welding region (130, 230, 330, 430, 530, 730) has a second thickness in the welding region (131), wherein the second welding region (130, 230, 330, 430, 530, 730) has a second connecting surface (134, 234), an outer edge (136) and a side wall (132), wherein the first connecting surface (154, 254) is adjacent to the second joining surface (134, 234) such that a weld joint (170, 370, 570) is formed between the first welding region (150, 250, 350, 450, 550, 750) and the second welding region (130, 230, 330, 430, 530, 730) at a connection point between the outer edge (156) and the outer edge (136); a weld bead formed along the weld joint (170, 370, 570) connecting the first weld area (150, 250, 350, 450, 550, 750) and the second weld area (130, 230, 330, 430, 530, 730); wherein the weld joint (170, 370, 570) defines a weld angle (θ) that is at least 90° along the length of the weld joint (170, 370, 570). [16] The bicycle according to claim 15, wherein the welding angle (θ) varies along the length of the weld joint (170, 370, 570). [17] The bicycle according to claim 15, wherein the welding angle (θ) is substantially constant along the length of the weld joint (170, 370, 570). [18] The bicycle according to claim 15, wherein the first connecting surface (154, 254) and the second connecting surface (134, 234) are substantially planar. [19] The bicycle according to claim 15, wherein the first connecting surface (154, 254) is convex and the second connecting surface (134, 234) is concave. [20] A method of welding a bicycle, comprising the steps of: Arranging the upper tube (40, 140, 240, 340, 440, 540, 640, 740) adjacent to a steerer tube (110), wherein the upper tube (40, 140, 240, 340, 440, 540, 640, 740) has a first tube part (141) and a first weld area (150, 250, 350, 450, 550, 750), wherein the first weld area (150, 250, 350, 450, 550, 750) has a first joining surface (154, 254), an outer edge (156) and a side wall (152), wherein the side wall (152) extends from the upper tube (40, 140, 240, 340, 440, 540, 640, 740); Arranging a lower tube (50, 120, 220, 320, 420, 520, 620, 720) adjacent to the steerer tube (110), the lower tube (50, 120, 220, 320, 420, 520, 620, 720) having a second tube portion (121) and a second weld region (130, 230, 330, 430, 530, 730); Arranging the first weld region (150, 250, 350, 450, 550, 750) adjacent to the second weld region (130, 230, 330, 430, 530, 730) to form a weld joint (170, 370, 570), wherein the weld joint (170, 370, 570) defines a weld angle (θ) that is at least 90° along the length of the weld joint (170, 370, 570); and Welding the first welding area (150, 250, 350, 450, 550, 750) and the second welding area (130, 230, 330, 430, 530, 730), essentially at the weld joint (170, 370, 570).
Citation Information
Patent Citations
Bicycle frame
US20110278816A1