阅读说明：本技术 踏板车、车架及前部支撑组合管件 (Scooter, frame and front support combined pipe fitting ) 是由 叶健荣 毕白春 邓剑 付品磊 于 2019-10-31 设计创作，主要内容包括：本发明涉及一种踏板车、车架及前部支撑组合管件。前部支撑组合管件包括主管,两个边管,及前横管。两个边管均与主管相连。前横管的端面与边管的侧壁相吻合,前横管的端面与边管的侧壁焊接连接并形成焊缝。前横管包括横管部及分别连接于横管部的两端的两个第一过渡吻合部。第一过渡吻合部吻接边管,第一过渡吻合部设置于横管部与边管相连形成的钝角区域的内侧。由于前横管的端面与边管的侧壁相吻合,使得前横管的端面与边管的侧壁之间结合牢固；此外,第一过渡吻合部能实现前横管承受更大载荷,能避免前横管的端面与边管的侧壁之间的焊缝的后侧焊缝部位出现应力集中现象,从而能避免边管受力作用下出现应力集中的不良缺陷。(The invention relates to a scooter, a frame and a front support combined pipe fitting. The front support combined pipe fitting comprises a main pipe, two side pipes and a front transverse pipe. Both side pipes are connected with the main pipe. The end surface of the front transverse pipe is matched with the side wall of the side pipe, and the end surface of the front transverse pipe is welded with the side wall of the side pipe to form a welding seam. The front transverse tube comprises a transverse tube part and two first transition inosculating parts respectively connected to two ends of the transverse tube part. The first transition inosculating part is matched with the side pipe and arranged at the inner side of an obtuse angle area formed by connecting the transverse pipe part and the side pipe. The end surface of the front transverse pipe is matched with the side wall of the side pipe, so that the end surface of the front transverse pipe is firmly combined with the side wall of the side pipe; in addition, the first transition inosculating part can realize that the front transverse tube bears larger load, and can avoid the phenomenon of stress concentration at the rear side welding seam part of the welding seam between the end surface of the front transverse tube and the side wall of the side tube, thereby avoiding the bad defect of stress concentration under the stress action of the side tube.)

1. A front support unitized tube, comprising:

the device comprises a main pipe and two side pipes, wherein the two side pipes are connected with the main pipe;

the preceding violently pipe, the terminal surface of preceding violently pipe with the lateral wall of limit pipe is identical, the terminal surface of preceding violently pipe with the lateral wall welded connection of limit pipe forms the welding seam, preceding violently pipe include horizontal pipe portion and connect respectively in two first transition anastomosis portions at the both ends of horizontal pipe portion, first transition anastomosis portion osculating the limit pipe, first transition anastomosis portion set up in horizontal pipe portion with the inboard in the obtuse angle region that the limit pipe links to each other and forms.

2. The front support composite pipe according to claim 1, wherein the first transition anastomotic portion is a first inclined wall inclined with respect to an axial direction of the transverse pipe portion, and the first inclined wall is smoothly transited to a sidewall of the side pipe; the arc convex surface of first skew wall orientation the lateral wall of limit pipe, first skew wall be close to in the direction of limit pipe with the contained angle between the lateral wall of limit pipe reduces gradually.

3. The front support composite tubular member of claim 2, wherein said cross tubular portion and said first transition anastomosis portion are of unitary construction; or the transverse pipe part and the first transition anastomosis part are welded and connected with each other.

4. The front support composite pipe of claim 2, wherein the weld is a circumferential weld; the welding seam comprises a lower side welding seam and an upper side welding seam which is arranged opposite to the lower side welding seam, and the upper side welding seam comprises a smooth convex seam and a smooth concave seam which are connected with the smooth convex seam in sequence along the axis direction of the side pipe.

5. The front support combination pipe fitting of claim 4, wherein the lower side weld comprises a first weld segment and a second weld segment arranged in sequence along the axis direction of the side pipe, one end of the first weld segment is connected with the smooth convex seam, the other end of the first weld segment is connected with one end of the second weld segment, and the other end of the second weld segment is connected with the smooth concave seam;

when the front support combined pipe fitting is placed on a horizontal plane in a normal posture, when the front support combined pipe fitting is seen from top to bottom along the vertical direction, the upper side welding seam is intersected with the lower side welding seam, the smooth convex seam is closer to the axis of the side pipe relative to the first welding seam section, and the second welding seam section is closer to the axis of the side pipe relative to the smooth concave seam.

6. The front support composite pipe of claim 1, wherein the front cross tube further comprises two second transition engaging portions respectively connected to two ends of the cross tube portion, the second transition engaging portions engaging the side tubes, the second transition engaging portions being disposed inside acute angle regions formed by the connection of the cross tube portion and the side tubes; the second transition anastomosis portion is a second inclined wall inclined relative to the axial direction of the transverse pipe portion, and the second inclined wall is connected to the side wall of the side pipe portion in a smooth transition mode through the side wall of the end portion of the transverse pipe portion.

7. The front support composite tubular member of claim 6, wherein said cross tubular portion and said second transition anastomosis portion are of a unitary construction; or the transverse pipe part and the second transition anastomosis part are welded and connected with each other.

8. The front support composite pipe according to any one of claims 1 to 7, wherein a projection of an end surface of the front cross pipe on a plane perpendicular to an axial direction of the cross pipe portion is elliptical, circular groove-shaped, or drop-shaped; alternatively, the first and second electrodes may be,

the welding seam is an annular welding seam, and the interval between the lower side welding seam of the welding seam and the upper side welding seam of the welding seam is gradually increased and then gradually decreased in the axial extension direction of the side pipe; alternatively, the first and second electrodes may be,

an included angle a between a welding seam closest to the lower edge part of the side pipe on the lower side welding seam part of the welding seam and a corresponding closest point on the lower edge part of the side pipe and the axis of the side pipe is 30-60 degrees; alternatively, the first and second electrodes may be,

an included angle b between a welding seam point on the upper side welding seam part of the welding seam, which is closest to the upper edge part of the side pipe, and a corresponding closest point on the upper edge part of the side pipe and is relative to the axis of the side pipe is 30-60 degrees; alternatively, the first and second electrodes may be,

the front transverse pipe comprises a first transverse pipe split body and a second transverse pipe split body; the first transverse pipe split body is connected with the second transverse pipe split body, the first transverse pipe split body is positioned above the second transverse pipe split body, and the wall thickness of the first transverse pipe split body is larger than that of the second transverse pipe split body; the bottom end of the main pipe is connected with the middle part of the front transverse pipe; the end part of the front transverse pipe is connected with the bent pipe section of the side pipe; the first transverse pipe split body and the second transverse pipe split body are integrally formed through stamping; the first transverse pipe split body is connected with the second transverse pipe split body in a welding mode.

9. A vehicle frame comprising the front support assembly of any one of claims 1 to 8.

10. A scooter, comprising a front support assembly as claimed in any one of claims 1 to 8.

Technical Field

The invention relates to the technical field of vehicles, in particular to a scooter, a frame and a front support combined pipe fitting.

Background

Scooters are a popular vehicle. The scooter includes a frame including a front support assembly positioned at the front of the body. The front support combined pipe fitting comprises a main pipe and two side pipes arranged on two sides of the main pipe. Generally, for a front support assembly tube having a main tube not connected to a middle cross tube of a vehicle frame, the front support assembly tube further includes a front cross tube connected to two side tubes, and the overall structural stability of the front support assembly tube is enhanced by the front cross tube. However, in the using process, referring to fig. 10, the weld C between the end portions of the side tubes and the front cross tubes overlaps or is close to the stress concentration area a, and the side walls corresponding to the end portions of the side tubes and the front cross tubes are prone to cracking due to stress concentration.

Disclosure of Invention

Therefore, the defects of the prior art are overcome, and the scooter, the frame and the front support combined pipe fitting can avoid the undesirable phenomenon that the side pipe cracks in the using process.

The technical scheme is as follows: a front support unitized tube, comprising: the device comprises a main pipe and two side pipes, wherein the two side pipes are connected with the main pipe; the preceding violently pipe, the terminal surface of preceding violently pipe with the lateral wall of limit pipe is identical, the terminal surface of preceding violently pipe with the lateral wall welded connection of limit pipe forms the welding seam, preceding violently pipe include horizontal pipe portion and connect respectively in two first transition anastomosis portions at the both ends of horizontal pipe portion, first transition anastomosis portion osculating the limit pipe, first transition anastomosis portion set up in horizontal pipe portion with the inboard in the obtuse angle region that the limit pipe links to each other and forms.

The end surface of the front transverse pipe is matched with the side wall of the side pipe, so that the end surface of the front transverse pipe is firmly combined with the side wall of the side pipe; in addition, the tip of preceding violently managing connects through the anastomotic portion osculating of first transition the side tube, the anastomotic portion of first transition can realize that the side tube bears bigger load, can avoid the stress concentration phenomenon to appear in the rear side welding seam position of the welding seam between the terminal surface of preceding violently managing and the lateral wall of side tube to can avoid the side tube atress effect down because stress concentration leads to the bad defect of brittle fracture.

In one embodiment, the first transition anastomosis portion is a first inclined wall inclined relative to the axial direction of the transverse tube portion, and the first inclined wall is smoothly connected to the side wall of the side tube in a transition manner; the arc convex surface of first skew wall orientation the lateral wall of limit pipe, first skew wall be close to in the direction of limit pipe with the contained angle between the lateral wall of limit pipe reduces gradually.

In one embodiment, the cross-tube portion and the first transition anastomosis portion are of a unitary construction; or the transverse pipe part and the first transition anastomosis part are welded and connected with each other.

In one embodiment, the weld is a ring weld; the welding seam comprises a lower side welding seam and an upper side welding seam which is arranged opposite to the lower side welding seam, and the upper side welding seam comprises a smooth convex seam and a smooth concave seam which are connected with the smooth convex seam in sequence along the axis direction of the side pipe.

In one embodiment, the lower side weld comprises a first weld segment and a second weld segment which are sequentially arranged along the axial direction of the side pipe, one end of the first weld segment is connected with the smooth convex seam, the other end of the first weld segment is connected with one end of the second weld segment, and the other end of the second weld segment is connected with the smooth concave seam;

when the front support combined pipe fitting is placed on a horizontal plane in a normal posture, when the front support combined pipe fitting is seen from top to bottom along the vertical direction, the upper side welding seam is intersected with the lower side welding seam, the smooth convex seam is closer to the axis of the side pipe relative to the first welding seam section, and the second welding seam section is closer to the axis of the side pipe relative to the smooth concave seam.

In one embodiment, the front transverse pipe further comprises two second transition inosculating parts respectively connected to two ends of the transverse pipe part, the second transition inosculating parts are inosculated with the side pipe, and the second transition inosculating parts are arranged on the inner side of an acute angle area formed by connecting the transverse pipe part and the side pipe; the second transition anastomosis portion is a second inclined wall inclined relative to the axial direction of the transverse pipe portion, and the second inclined wall is connected to the side wall of the side pipe portion in a smooth transition mode through the side wall of the end portion of the transverse pipe portion.

In one embodiment, the cross-tube portion and the second transition anastomosis portion are of a unitary construction; or the transverse pipe part and the second transition anastomosis part are welded and connected with each other.

In one embodiment, the projection of the end surface of the front transverse pipe on a plane perpendicular to the axial direction of the transverse pipe part is in an oval shape, a circular groove shape or a water drop shape; alternatively, the first and second electrodes may be,

the welding seam is an annular welding seam, and the interval between the lower side welding seam of the welding seam and the upper side welding seam of the welding seam is gradually increased and then gradually decreased in the axial extension direction of the side pipe; alternatively, the first and second electrodes may be,

an included angle a between a welding seam closest to the lower edge part of the side pipe on the lower side welding seam part of the welding seam and a corresponding closest point on the lower edge part of the side pipe and the axis of the side pipe is 30-60 degrees; alternatively, the first and second electrodes may be,

an included angle b between a welding seam point on the upper side welding seam part of the welding seam, which is closest to the upper edge part of the side pipe, and a corresponding closest point on the upper edge part of the side pipe and is relative to the axis of the side pipe is 30-60 degrees; alternatively, the first and second electrodes may be,

the front transverse pipe comprises a first transverse pipe split body and a second transverse pipe split body; the first transverse pipe split body is connected with the second transverse pipe split body, the first transverse pipe split body is positioned above the second transverse pipe split body, and the wall thickness of the first transverse pipe split body is larger than that of the second transverse pipe split body; the bottom end of the main pipe is connected with the middle part of the front transverse pipe; the end part of the front transverse pipe is connected with the bent pipe section of the side pipe; the first transverse pipe split body and the second transverse pipe split body are integrally formed through stamping; the first transverse pipe split body is connected with the second transverse pipe split body in a welding mode.

A vehicle frame comprises the front support combined pipe fitting.

The frame comprises the front support combined pipe fitting, so that the technical effect is brought by the front support combined pipe fitting, the beneficial effects are the same as those of the front support combined pipe fitting, and the description is omitted.

A scooter comprises the front support combined pipe fitting.

The scooter comprises the front support combined pipe fitting, the technical effect of the scooter is brought by the front support combined pipe fitting, the beneficial effect of the scooter is the same as that of the front support combined pipe fitting, and the detailed description is omitted.

Drawings

FIG. 1 is a schematic bottom view of a front support assembly according to one embodiment of the present invention;

FIG. 2 is a schematic view of a front support assembly of an embodiment of the present invention;

FIG. 3 is a schematic view of another embodiment of a front support assembly of the present invention;

FIG. 4 is an exploded view of the front cross tube of the front support assembly of one embodiment of the present invention;

fig. 5 is a schematic structural view of an end surface of a front cross tube in the front support assembly according to an embodiment of the present invention;

fig. 6 is a schematic structural view of an end surface of a front cross tube in the front support assembly according to another embodiment of the present invention;

fig. 7 is a schematic structural view of an end surface of a front cross tube in the front support assembly according to yet another embodiment of the present invention;

FIG. 8 is a cross-sectional view of the front cross tube at a central portion of the front support assembly according to one embodiment of the present invention;

FIG. 9 is a schematic top view of the front cross tube and the side tubes of the front support assembly according to one embodiment of the present invention;

FIG. 10 is a graph illustrating the stress effect of the front cross tube and side tubes during use of the conventional scooter;

fig. 11 is a stress effect diagram of the front cross tube and the side tube during the use of the scooter according to an embodiment of the present invention.

Reference numerals:

10. a main pipe; 20. a side tube; 21. a lower edge portion; 22. an upper edge portion; 30. a front horizontal tube; 31. a cross pipe section; 32. a first transition anastomosis; 33. a second transition anastomosis; 34. the first transverse pipe is split; 35. the second transverse pipe is split; 40. welding seams; 41. a lower weld; 411. a first weld segment; 412. a second weld segment; 42. an upper side weld; 421. smooth convex seams; 422. and 4, smoothing concave seams.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In the description of the present invention, it is to be understood that the terms "first", "second" and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the description of the present invention, it should be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly connected" to another element, there are no intervening elements present.

Generally, because the material is deformed when the bent section of the side tube is formed, the radial section of the bent section of the side tube is changed from a circle to an ellipse, and the two end edges of the front transverse tube are formed by punching edges and are cylindrical surfaces, the gap at the lap joint of the side tube and the front transverse tube is large, the quality of a welding seam is difficult to control, and the combination firmness between the side tube and the front transverse tube is poor.

In addition, the rear side weld joint part of the weld joint formed between the front transverse pipe and the side pipe is easy to have the bad phenomenon of brittle fracture due to the stress concentration phenomenon.

In one embodiment, referring to fig. 1, 2 and 11, a front support assembly includes a main tube 10, two side tubes 20, and a front cross tube 30. Both of the side pipes 20 are connected to the main pipe 10. The end surface of the front transverse tube 30 is matched with the side wall of the side tube 20, and the end surface of the front transverse tube 30 is welded with the side wall of the side tube 20 to form a welding seam 40. The front cross tube 30 includes a cross tube portion 31 and two first transition inosculating portions 32 respectively connected to two ends of the cross tube portion 31. The first transition anastomosis portion 32 is anastomosed with the side tube 20, and the first transition anastomosis portion 32 is disposed at the inner side of an obtuse angle region formed by connecting the cross tube portion 31 and the side tube 20.

The end surface of the front transverse pipe 30 is matched with the side wall of the side pipe 20, so that the end surface of the front transverse pipe 30 is firmly combined with the side wall of the side pipe 20; in addition, the end of the front transverse tube 30 is engaged with the side tube 20 through the first transition engaging portion 32, the first transition engaging portion 32 can enable the side tube 20 to bear larger load, and the stress concentration phenomenon at the rear side welding seam 40 of the welding seam 40 between the end surface of the front transverse tube 30 and the side wall of the side tube 20 can be avoided, so that the bad defect of brittle fracture caused by stress concentration under the stress action of the side tube 20 can be avoided.

Further, referring to fig. 1 and 9, the first transition matching portion 32 is a first inclined wall inclined with respect to the axial direction of the transverse tube portion 31, and the first inclined wall is smoothly connected to the side wall of the side tube 20. The arc convex surface of the first inclined wall faces the side wall of the side pipe 20, and the included angle between the first inclined wall and the side wall of the side pipe 20 in the direction close to the side pipe 20 is gradually reduced. In this way, since the arc convex surface of the first inclined wall faces the side wall of the side tube 20, the included angle between the first inclined wall and the side wall of the side tube 20 in the direction close to the side tube 20 is gradually reduced, and on one hand, the first inclined wall can be better attached to the side tube 20; on the other hand, compared with the traditional structure, the stress concentration position is changed, so that the stress concentration area B avoids the area where the welding seam 40 is positioned, and the overlapping or partial overlapping or approaching of the stress concentration area B and the area where the welding seam 40 is positioned is avoided, thereby avoiding the defect of brittle fracture of the side pipe 20 due to stress concentration.

In one embodiment, referring to fig. 9, the weld 40 is a circular weld. The weld 40 includes a lower weld 41 and an upper weld 42 opposite to the lower weld 41. The upper weld 42 includes a smooth convex seam 421 and a smooth concave seam 422 connected to the smooth convex seam 421, which are sequentially arranged along the axial direction of the side tube 20. Like this, the lateral part pipe wall at the downside welding seam 41 place of the terminal surface of preceding violently pipe 30 and the lateral part pipe wall at upside welding seam 42 place realize tightly holding the lateral wall of limit pipe 20, on the one hand, combine firmly, on the other hand, for traditional structure, change stress concentration position, make stress concentration district B avoid the welding seam 40 regional, avoid stress concentration district B and welding seam 40 regional overlapping or partial overlapping or be close to avoid limit pipe 20 because the defect of the brittle fracture appears in stress concentration.

It should be noted that "round" in this embodiment means gradually changing, gently changing, and not suddenly changing. That is, for the rounded convex seam 421 or the rounded concave seam 422, the broken seam is obviously excluded, and may be, for example, a circular arc seam, a wavy seam, an elliptical seam, or the like.

Further, referring to fig. 9, the lower weld 41 includes a first weld segment 411 and a second weld segment 412 sequentially arranged along the axial direction of the side tube 20. One end of the first weld segment 411 is connected to the smooth convex seam 421, the other end of the first weld segment 411 is connected to one end of the second weld segment 412, and the other end of the second weld segment 412 is connected to the smooth concave seam 422. When the front support combination pipe is placed on a horizontal plane in a normal posture, the upper side weld joint 42 intersects the lower side weld joint 41 when viewed from the top in the vertical direction, the smooth convex seam 421 is closer to the axis of the side pipe 20 than the first weld joint segment 411, and the second weld joint segment 412 is closer to the axis of the side pipe 20 than the smooth concave seam 422. Like this, the lateral part pipe wall at the downside welding seam 41 place of the terminal surface of preceding violently pipe 30 and the lateral part pipe wall at upside welding seam 42 place realize tightly holding the lateral wall of limit pipe 20, on the one hand, combine firmly, on the other hand, for traditional structure, change stress concentration position, make stress concentration district B avoid the welding seam 40 regional, avoid stress concentration district B and welding seam 40 regional overlapping or partial overlapping or be close to avoid limit pipe 20 because the defect of the brittle fracture appears in stress concentration.

In one embodiment, referring to fig. 9, the front cross tube 30 further includes two second transition anastomoses 33 respectively connected to two ends of the cross tube portion 31. The second transition matching part 33 matches with the side tube 20, and the second transition matching part 33 is arranged at the inner side of an acute angle area formed by connecting the transverse tube part 31 and the side tube 20. That is, the first transition anastomosis 32 is located on a side of the front cross tube 30 facing away from the main tube 10, and the second transition anastomosis 33 is located on a side of the front cross tube 30 facing toward the main tube 10. Thus, the end of the front cross tube 30 is engaged with the side tube 20 through the second transition engaging portion 33, the second transition engaging portion 33 can enable the front cross tube 30 to bear larger load, and the stress concentration phenomenon at the front side weld 40 of the weld 40 between the end surface of the front cross tube 30 and the side wall of the side tube 20 can be avoided, so that the bad defect of brittle fracture caused by stress concentration under the stress action of the side tube 20 can be avoided.

Further, referring to fig. 9, the second transition matching portion 33 is a second inclined wall inclined with respect to the axial direction of the cross tube portion 31, and the second inclined wall is smoothly transited from the side wall of the end portion of the cross tube portion 31 to the side wall of the side tube 20. So, the second skew wall of preceding violently pipe 30 is equivalent to the turn-ups structure that the orientation was kept away from in the axis direction turn-ups of violently managing portion 31, and turn-ups structure plays the bearing effect to limit pipe 20, changes stress concentration position, makes stress concentration district B avoid the welding seam 40 regional, avoids stress concentration district B and the regional overlapping or partial overlapping or being close in welding seam 40 place to avoid limit pipe 20 because stress concentration and the defect of brittle fracture appears.

In one embodiment, the cross-tube portion 31 and the first transition anastomosis portion 32 are of a unitary structure; alternatively, the cross tube portion 31 and the first transition anastomosis portion 32 are welded to each other.

In one embodiment, the cross-tube portion 31 and the second transition anastomosis portion 33 are of a unitary construction; alternatively, the cross tube part 31 and the second transition anastomosis part 33 are welded to each other.

In addition, when the front cross tube 30 is close to the outer diameter of the side tube 20, the weld 40 overlapping the side tube 20 and the front cross tube 30 extends to the lower edge portion 21 where the bending stress of the side tube 20 is large (the lower edge portion 21 refers to a portion where the side wall of the side tube 20 is closest to the ground in the circumferential direction of the side wall of the side tube 20 when the scooter is normally placed on a horizontal ground), and correspondingly, the upper edge portion 22 refers to a portion where the side wall of the side tube 20 is farthest from the ground in the circumferential direction of the side wall of the side tube 20), and the material in this region is close to the weld 40 and is easily affected by the heat of the weld 40 to become brittle, so that the lower edge portion 21 of the side tube 20 is easily cracked due to the external force.

Further, the welding seam 40 is an annular welding seam, a lower side welding seam 41 part of the welding seam 40 and the lower edge part 21 of the side tube 20 are arranged at intervals, and the distance between the lower side welding seam 41 part of the welding seam 40 and an upper side welding seam 42 part of the welding seam 40 is smaller than the distance between a front side welding seam 40 part of the welding seam 40 and a rear side welding seam 40 part of the welding seam 40. Thus, because the lower side weld joint 41 part of the weld joint 40 and the lower edge part 21 of the side tube 20 are arranged at intervals, the distance between the lower side weld joint 41 part of the weld joint 40 and the upper side weld joint 42 part of the weld joint 40 is smaller than the distance between the front side weld joint 40 part of the weld joint 40 and the rear side weld joint 40 part of the weld joint 40, on one hand, the end surface of the front transverse tube 30 and the side wall of the side tube 20 can be firmly combined, on the other hand, the weld joint 40 can be far away from the lower edge part 21 of the side tube 20 as far as possible, so that the lower edge part 21 of the side tube 20 is less affected by heat of the weld joint 40, and the bad phenomenon that the lower edge part 21 of the side tube 20 is easily cracked due.

It should be noted that the lower weld 41, the upper weld 42, the front weld 40 and the rear weld 40 of the weld 40 respectively refer to that when the scooter is normally placed on a horizontal ground, the lower weld 41 is located on the lower portion of the weld 40, the upper weld 42 is located on the upper portion, the front weld 40 is located on the portion close to the main pipe 10, and the rear weld 40 is located on the portion far from the main pipe 10.

In one embodiment, referring to fig. 5 to 8, a projection of the end face of the front cross tube 30 on a plane perpendicular to the axial direction of the front cross tube 30 is an ellipse, a circular groove, or a drop shape. In this way, the projection of the shape of the weld 40 formed between the end surface of the front cross tube 30 and the side wall of the side tube 20 on the plane perpendicular to the axial direction of the front cross tube 30 is elliptical, circular groove or drop shape, so that on one hand, the end surface of the front cross tube 30 and the side wall of the side tube 20 can be firmly combined, and on the other hand, the weld 40 can be far away from the lower edge part 21 of the side tube 20 as far as possible, so that the lower edge part 21 of the side tube 20 is less affected by the heat of the weld 40, and the bad phenomenon that the lower edge part 21 of the side tube 20 is easily cracked due to the external force is avoided. The drop shape is illustrated in fig. 5, and can be understood as being formed by splicing a part of lines of an oblong shape with a semicircular line. The round groove shape can be understood as a shape obtained by chamfering four right angles of a rectangle, as shown in fig. 6. While the oval shape is shown in figure 7. In addition, the cross-sectional view of the front cross tube 30 at the center portion is shown in fig. 8 as being circular, i.e., the center portion of the front cross tube 30 is configured as a round tube.

It will be appreciated that the weld 40 corresponds to the location where the end face of the front cross tube 30 contacts the side wall of the side tube 20, and in one embodiment, the spacing between the lower weld 41 of the weld 40 and the upper weld 42 of the weld 40 is first progressively larger and then progressively smaller in the axial extension of the side tube 20. Thus, the end surface of the front cross tube 30 is easily and evenly transitionally connected to the side wall of the side tube 20, so that the end surface of the front cross tube 30 is firmly combined with the side wall of the side tube 20, the phenomenon of stress concentration can be avoided, and the front cross tube can bear larger load. In addition, the lower edge portion 21 refers to a portion where the side wall of the side tube 20 is closest to the ground in the direction of the circumferential surface of the side wall of the side tube 20 when the scooter is normally placed on a horizontal ground; accordingly, the upper edge portion 22 refers to a portion of the side wall of the side pipe 20 that is farthest from the ground in the circumferential surface direction of the side wall of the side pipe 20.

In one embodiment, referring to fig. 2 again, an angle a between a weld point on the lower weld 41 of the weld 40 closest to the lower edge portion 21 of the side tube 20 and a corresponding closest point on the lower edge portion 21 of the side tube 20 is 30 to 60 degrees with respect to the axis of the side tube 20. Therefore, on one hand, the welding seam 40 can be ensured to be far away from the lower edge part 21 of the side pipe 20 as far as possible, so that the lower edge part 21 of the side pipe 20 is less affected by the heat of the welding seam 40, and the bad phenomenon that the lower edge part 21 of the side pipe 20 is easy to crack in a brittle way under the action of external force is avoided; on the other hand, the end face of the front cross tube 30 is more strongly bonded to the side wall of the side tube 20.

Furthermore, an included angle a between a weld point closest to the lower edge portion 21 of the side tube 20 at the lower side weld 41 of the weld 40 and a corresponding closest point on the lower edge portion 21 of the side tube 20 with respect to the axis of the side tube 20 is 40 to 50 degrees. Specifically, the angle between the weld point closest to the lower edge portion 21 of the side tube 20 at the lower weld 41 of the weld 40 and the corresponding closest point at the lower edge portion 21 of the side tube 20 with respect to the axis of the side tube 20 is 45 degrees.

In one embodiment, referring to fig. 1 to 3, in order to make the upper weld 42 of the weld 40 as far away from the upper edge 22 of the side tube 20 as possible, the angle b between the weld point on the upper weld 42 of the weld 40 closest to the upper edge 22 of the side tube 20 and the corresponding closest point on the upper edge 22 of the side tube 20 is 30 to 60 degrees with respect to the axis of the side tube 20, similar to the arrangement of the lower weld 41 of the weld 40. Thus, the welding seam 40 can be far away from the upper edge part 22 of the side pipe 20 as far as possible, so that the upper edge part 22 of the side pipe 20 is less affected by the heat of the welding seam 40, and the bad phenomenon that the upper edge part 22 of the side pipe 20 is easy to crack due to the external force is avoided.

Further, referring to fig. 1 to 3, an angle b between a weld point on the upper weld 42 of the weld 40 closest to the upper edge 22 of the side tube 20 and a corresponding closest point on the upper edge 22 of the side tube 20 with respect to the axis of the side tube 20 is 40 to 50 degrees. Specifically, the angle between the weld point closest to the upper edge portion 22 of the side tube 20 at the upper weld 42 of the weld 40 and the corresponding closest point on the upper edge portion 22 of the side tube 20 with respect to the axis of the side tube 20 is 45 degrees.

In one embodiment, referring to FIG. 4, the front cross tube 30 includes a first cross tube section 34 and a second cross tube section 35. The first transverse pipe body 34 is connected with the second transverse pipe body 35, the first transverse pipe body 34 is located above the second transverse pipe body 35, and the wall thickness of the first transverse pipe body 34 is larger than that of the second transverse pipe body 35. Therefore, the requirements of the front support combined pipe fitting on weight and strength and rigidity are met.

Further, the first horizontal tube section 34 and the second horizontal tube section 35 are integrally formed by stamping. In addition, the first transverse tube body 34 and the second transverse tube body 35 may be connected by welding.

In one embodiment, referring to fig. 1-3, the bottom end of the primary tube 10 is connected to the middle of the front cross tube 30. Therefore, the front support combined pipe fitting has good structural stability and can bear larger load.

In addition, the front cross tube 30 is often disposed at a forward position with both ends of the front cross tube 30 overlapping the bent tube sections of the two side tubes 20, respectively, in view of increasing the space disposed below the footrests as much as possible. That is, the ends of the front cross tubes 30 are connected to the bent tube sections of the side tubes 20.

In one embodiment, a vehicle frame comprises the front support assembly of any of the above embodiments.

The frame comprises the front support combined pipe fitting, so that the technical effect is brought by the front support combined pipe fitting, the beneficial effects are the same as those of the front support combined pipe fitting, and the description is omitted.

In one embodiment, a scooter comprises the front support composite tubular member of any of the above embodiments.

The scooter comprises the front support combined pipe fitting, the technical effect of the scooter is brought by the front support combined pipe fitting, the beneficial effect of the scooter is the same as that of the front support combined pipe fitting, and the detailed description is omitted.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.