Headrest tube necking mould

Abstract

The invention discloses a headrest tube necking mould, which comprises a mould body; a necking hole communicating with the outside is formed in the mould body; the hole diameter of the necking hole is sequentially reduced from outside to inside, and the inner wall of the necking hole is a concave arc surface. The hole diameter of the outer end of the necking hole is d; the inner wall of the necking hole is divided into three arc surface sections which are tangential sequentially along a hole center line; any plane which passes through along the hole center line is crossed with the inner wall of the necking hole, so that a crossed curve can be obtained; the circular-arc radius of the outer side section of the crossed curve is Ra, and the arc length of the outer side section is La; the circular-arc radius of the middle section is Rb and the arc length of the middle section is Lb; the circular-arc radius of the inner side section is Rc and arc length of the inner side section is Lc; Ra:Rb:Rc is equal to (18-22) to (5-8) to (1.5-3); and La:Lb:Lc is equal to (7-8): (9-10):(2-4); and Ra is equal to (1.3-1.5)d. With the adoption of the headrest tube necking mould disclosed by the invention, a necking rate of the tube end of a headrest tube can be 50% or higher once, multi-time necking operation is not needed, the surface at the necking hole of the headrest tube is smooth and free of folds, and the forming quality for the tube end of the headrest tube is high.

Description

technical field [0001] The invention relates to a mold, in particular to a necking mold for a headrest tube. Background technique [0002] When a vehicle collides with the rear, the human body will fall backward due to inertia. At this time, the pressure of vehicle acceleration or deceleration is concentrated on the fragile neck and head of the human body, and the headrest acts as a buffer to protect the human head. Headrests are mainly divided into two categories, one is non-adjustable and the other is adjustable. The headrest tube of the adjustable car headrest is connected with the headrest tube cover on the seat back frame, and the height of the car headrest is adjusted by sliding along the headrest tube cover through the headrest tube, and the headrest and the seat back frame are assembled When the headrest tube end is smaller and smoother, the assembly is easier; at the same time, when the vehicle collides, the passengers in the rear row may collide with the headrest ...

AI Technical Summary

Problems solved by technology

[0003] At present, most of the molds for necking the headrest tube end use smooth necking holes, which makes the necking rate of the pipe end not greater than 25%, otherwise the pipe wall at the necking point will be wrinkled and damaged

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