CN-122007812-A - Electric bicycle handlebar preparation method and electric bicycle handlebar

CN122007812ACN 122007812 ACN122007812 ACN 122007812ACN-122007812-A

Abstract

The application discloses a preparation method of an electric bicycle handlebar and the electric bicycle handlebar, and solves the technical problem that the prior art steel handlebar is not suitable for fatigue performance after light weight and thinning. The manufacturing method of the electric bicycle handlebar comprises the steps of pre-bending the edge of a steel strip into an arc shape, rolling the steel strip into a tube shape, performing high-frequency welding to obtain a high-frequency welded pipe, inserting the high-frequency welded pipe into a bending die to bend the high-frequency welded pipe into a shape to obtain an elbow, welding the elbow and an accessory through gas metal arc welding to form a fillet weld, wherein the fillet weld is a concave weld, and welding the elbow and the accessory to obtain the handlebar. The structural stress of the handlebar prepared by the preparation method of the electric bicycle handlebar is obviously reduced, so that the risk of handlebar crack initiation is reduced, the service life of the handlebar is prolonged, and the fatigue performance of the handlebar is improved.

Inventors

WANG YUE
ZHANG SHAOJI
DONG XIANCHUN
WEI SHAODONG
LIU HONG
LI XUETAO
WANG JINGBAO
TIAN ZHIHONG
LIU XINYAO
LIU SHAOPENG
XIAO BAOLIANG

Assignees

首钢集团有限公司

Dates

Publication Date: 20260512
Application Date: 20260304

Claims (10)

1. The preparation method of the electric bicycle handlebar is characterized by comprising the following steps of: pre-bending the edge of the steel strip into an arc shape, rolling the steel strip into a tube shape, and performing high-frequency welding to obtain a high-frequency welded tube; inserting the high-frequency welded pipe into a bending die to bend and mold the high-frequency welded pipe to obtain an elbow; and welding the bent pipe and the accessory through gas metal arc welding, and forming a fillet weld, wherein the fillet weld is a concave weld, and the bent pipe and the accessory are welded to obtain the handlebar.
2. The method for manufacturing an electric bicycle handlebar according to claim 1, wherein the pre-bending the edges of the steel strip into an arc shape, then rolling the steel strip into a tube shape, and performing high-frequency welding to obtain a high-frequency welded tube, specifically comprising: The edges of the steel strips are subjected to multi-pass rolling pre-bending to form an arc shape through a roller press; rolling the steel strip into a tube shape through a plurality of groups of forming rollers, and forming an opening gap; the opening gap is welded and sealed at high frequency by a high-frequency welding machine, and slag is scraped from the outer seam; and passing the high-frequency welded pipe through a sizing roller set so as to enable the high-frequency welded pipe to reach the preset outer diameter size.
3. The method for manufacturing an electric bicycle handlebar according to claim 2, wherein the opening gap is subjected to high-frequency welding by a high-frequency welding machine, and the outer slit is scraped, and the width of the opening gap is less than or equal to 0.5mm; The frequency of the high-frequency welding machine is 200 KHz-450 kHZ, and the welding speed is 50-110 m/min; the misalignment amount of the two sides of the high-frequency welding pipe fusion line is smaller than or equal to 0.2mm, and the ratio of the extrusion amount in high-frequency welding to the thickness of the steel belt is 0.4-2; And the height difference between the welding line area and the surrounding matrix after the slag scraping of the outer seam is less than or equal to 0.2mm.
4. The method for manufacturing an electric bicycle handlebar according to claim 2, wherein the high-frequency welded pipe is passed through a sizing roller set so that the high-frequency welded pipe reaches a preset outer diameter size, wherein an outer diameter tolerance is + -0.1 mm, and the preset outer diameter size is 18-25 mm.
5. The method for manufacturing an electric bicycle handlebar according to claim 1, wherein the thickness of the steel strip is 1.4 mm-2.0 mm.
6. The method for manufacturing an electric bicycle handlebar according to claim 1, wherein the inserting the high-frequency welded pipe into a bending die to bend the high-frequency welded pipe into a bent pipe, specifically comprises: Inserting the high-frequency welded pipe into a bending die, wherein the deviation between the axis of the high-frequency welded pipe and the axis of the bending die is less than or equal to 0.1mm, and the ratio of the bending radius of the bending die to the preset outer diameter of the high-frequency welded pipe is greater than or equal to 2; Bending and forming the high-frequency welded pipe through a multi-axis linkage control system, wherein the bending speed of the bending die in a main bending section is less than or equal to 3.8 degrees/s, the bending speed of the bending die in a transition section is less than or equal to 5 degrees/s, and the maximum tensile strain at the outer side of the high-frequency welded pipe meets the following relational expression Wherein t is the thickness of the steel strip, R is the preset outer diameter size of the high-frequency welded pipe, And (5) the maximum tensile strain is applied to the outer side of the high-frequency welded pipe.
7. The method for manufacturing an electric bicycle handlebar according to claim 1, wherein in the welding of the bent pipe and the fitting by means of consumable electrode gas shielded welding, a welding wire having a diameter of 1.0mm to 1.2mm is used in the welding process; the included angle between the axis of the welding wire and the bent pipe ranges from 45 degrees to 75 degrees; the shielding gas in the welding process is 75% -97% Ar+3% -25% CO 2 .
8. The method according to claim 1, wherein in the welding of the bent pipe and the fitting by the consumable electrode gas shielded welding, a ratio of welding heat input to wall thickness is 1.4 to 3.0, a welding current is 110a to 190a, a voltage is 12v to 22v, and a welding speed is 5mm/s to 9mm/s.
9. The method according to claim 1, wherein in the welding of the elbow and the fitting by means of consumable electrode gas shielded welding and forming a fillet, the fillet is a concave weld, and the elbow side weld transition angle is less than or equal to 50 °; The ratio of the penetration to the thickness of the steel strip is 1/3-1, The ratio of the length of the welding leg to the thickness of the steel strip is 1-3.
10. An electric bicycle handlebar, characterized in that it is prepared by the method according to any one of claims 1-9.

Description

Electric bicycle handlebar preparation method and electric bicycle handlebar Technical Field The application belongs to the technical field of electric bicycles, and particularly relates to a preparation method of an electric bicycle handlebar and the electric bicycle handlebar. Background With the requirements that the whole mass of the electric bicycle cannot exceed 55kg being definitely limited in the technical specification of electric bicycle safety (GB 17761-2018), the electric bicycle industry comprehensively implements the application of high-strength materials and the design of thin-wall structure as key directions of light-weight technology. At present, the electric bicycle handle bar in the market is mostly manufactured by adopting low-strength carbon structural steel (such as Q195, yield strength ReL is less than or equal to 195 MPa), and the light weight potential is remarkable. However, in the high-strength thinning certification process, fatigue of the handle bar rack is not a problem frequently. With the reduction of the thickness of the material, the modulus of the section of the handlebar tube is directly reduced, and hidden danger is brought to the fatigue performance of the handlebar. Disclosure of Invention The application provides a preparation method of an electric bicycle handlebar and the electric bicycle handlebar, aiming at solving the technical problem that the prior steel handlebar is not good in fatigue performance after light weight and thinning. In a first aspect of the present application, there is provided a method for manufacturing an electric bicycle handlebar, comprising the steps of: pre-bending the edge of the steel strip into an arc shape, rolling the steel strip into a tube shape, and performing high-frequency welding to obtain a high-frequency welded tube; inserting the high-frequency welded pipe into a bending die to bend and mold the high-frequency welded pipe to obtain an elbow; and welding the bent pipe and the accessory through gas metal arc welding, and forming a fillet weld, wherein the fillet weld is a concave weld, and the bent pipe and the accessory are welded to obtain the handlebar. In some embodiments, the steel strip edge is pre-bent into an arc shape, then the steel strip is rolled into a tube shape, and high-frequency welding is performed, so as to obtain a high-frequency welded tube, which specifically comprises: The edges of the steel strips are subjected to multi-pass rolling pre-bending to form an arc shape through a roller press; rolling the steel strip into a tube shape through a plurality of groups of forming rollers, and forming an opening gap; the opening gap is welded and sealed at high frequency by a high-frequency welding machine, and slag is scraped from the outer seam; and passing the high-frequency welded pipe through a sizing roller set so as to enable the high-frequency welded pipe to reach the preset outer diameter size. In some embodiments, the opening gap is welded at high frequency by a high-frequency welding machine, and the width of the opening gap is less than or equal to 0.5mm in slag scraping of the outer seam; The frequency of the high-frequency welding machine is 200 KHz-450 kHZ, and the welding speed is 50-110 m/min; the misalignment amount of the two sides of the high-frequency welding pipe fusion line is smaller than or equal to 0.2mm, and the ratio of the extrusion amount in high-frequency welding to the thickness of the steel belt is 0.4-2; And the height difference between the welding line area and the surrounding matrix after the slag scraping of the outer seam is less than or equal to 0.2mm. In some embodiments, the high-frequency welded pipe is passed through a sizing roller set so that the high-frequency welded pipe reaches a preset outer diameter size, wherein the outer diameter tolerance is +/-0.1 mm, and the preset outer diameter size is 18-25 mm. In some embodiments, the steel strip has a thickness of 1.4mm to 2.0mm. In some embodiments, the inserting the high-frequency welded pipe into a bending die to bend the high-frequency welded pipe to obtain an elbow pipe specifically includes: Inserting the high-frequency welded pipe into a bending die, wherein the deviation between the axis of the high-frequency welded pipe and the axis of the bending die is less than or equal to 0.1mm, and the ratio of the bending radius of the bending die to the preset outer diameter of the high-frequency welded pipe is greater than or equal to 2; Bending and forming the high-frequency welded pipe through a multi-axis linkage control system, wherein the bending speed of the bending die in a main bending section is less than or equal to 3.8 degrees/s, the bending speed of the bending die in a transition section is less than or equal to 5 degrees/s, and the maximum tensile strain at the outer side of the high-frequency welded pipe meets the following relational expression Wherein t is the thickness of the steel strip, R is the preset