B column on vehicle and manufacturing method

Abstract

The invention relates to a B column on a vehicle and a manufacturing method. The B column comprises a B column body, an upper fixed portion fixed to a roof is arranged at the top of the B column body, and a lower fixed portion fixed to a threshold is arranged at the bottom of the B column body. The B column is characterized in that a hard area is arranged on the upper portion of the B column body, a soft area is arranged on the lower portion of the B column body, a transition area is arranged between the hard area and the soft area, a reinforcing pipe is arranged on the hard area, the hard area is a martensitic structure prepared by an ultrahigh-strength steel hot forming process, the strength of the martensitic structure is 1300-1500MPa, the soft area is a ferrite and pearlite structure or bainite structure prepared by slow cooling in an ultrahigh-strength steel hot forming process, the strength of the ferrite and pearlite structure or bainite structure is 500-700MPa, the reinforcing pipe is a hollow pipe prepared by a hydraulic forming process, and the wall thickness of the reinforcing pipe is 1.8mm+ / -30%. The sectional design of the reinforcing pipe can be flexibly changed according to the shape of the B column, so that the load of each section is more uniform, and the requirement of the vehicle for light weight is met.

Description

technical field [0001] The invention relates to a B-pillar on a vehicle and a manufacturing method thereof, belonging to the technical field of vehicle components. Background technique [0002] A car's B-pillar is the vertical beam on the car that sits between the front and rear seats of the cockpit and extends from the roof to the bottom of the car. The B-pillar not only supports the roof cover, but also bears the supporting force of the front and rear doors. Some additional parts are also installed on the B-pillar, such as the seat belts of the front seats, and sometimes the wiring harness. Therefore, most of the B-pillars have a convex radius to ensure better force transmission performance. The cross-sectional shape of the B-pillar of a modern car is relatively complicated, and it is welded by multiple pieces of stamped steel plates. With the development of automobile manufacturing technology, a closed cross-section center pillar that directly adopts hydroforming withou...

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Problems solved by technology

[0003] In the prior art, the B-pillar generally adopts cold stamping parts. Under the same strength, the weight of the cold stamping parts is large, which does not conform to the trend of lightweight

In addition, in order to strengthen the strength, the reinforcement plate is welded on the B-pillar, and the reinforcement plate and the B-pillar need to be formed and welded separately, which results in a large number of mold tooling and welding fixtures, which makes the processing cost higher; and the quality of welding Not suitable for control, not stable enough

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