Self-adaptive charging drawing forming method capable of preventing inverse bulging fracturing

A liquid-filled stretching and liquid-chamber technology, which is used in the field of liquid-filled stretching of hydraulic hydraulic presses, can solve problems such as difficulty in precise grasping, anti-expansion rupture, etc.

Active Publication Date: 2017-08-15
ZHEJIANG UNIV
View PDF4 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] In order to solve the problem that it is difficult to accurately grasp the hydraulic pressure of the liquid chamber in the traditional liquid-filled stretching process, resulting in anti-expansion and rupture, the present invention provides an adaptive liquid-filled stretching forming method that prevents anti-expansion and rupture
The self-adaptive liquid-filled stretch

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] With punch diameter 150 mm, tensile force (F n )=20000N, 1 mm thick No. 45 steel plate is a specific example, the constant force when the plate yields (F e ) is 29000N, and the critical force for sheet metal rupture (F σmax ) is 35000N. Firstly, the slider goes down in empty space, and starts to decelerate before touching the sheet, so that the punch starts to contact the sheet at a constant speed of 20 mm per second. Liquid chamber hydraulic pressure (F y )=8×20000÷(0.25×π×150²)≈9.06MPa, after the punch contacts the sheet, the liquid in the liquid chamber is compressed, and the hydraulic pressure in the liquid chamber increases gradually. When the hydraulic pressure in the liquid chamber (F y ) + tensile force (F n )=1.05×35000N= 36750N, gradually reduce the hydraulic pressure of the liquid chamber (F y ), hold the set value (F 0 ). As the punch continues to move down, the anti-expansion height is reduced to the set value of 0.1×150mm=1.5mm (H 0 ), the anti-exp...

Embodiment 2

[0024] With punch diameter 150 mm, tensile force (F n )=18000N, 1 mm thick aluminum alloy is a specific example, the constant force when the sheet yields (F e ) is 25000N, and the critical force for sheet metal rupture (F σmax ) is 33000N. Firstly, the slider goes down in empty space, and starts to decelerate before touching the sheet, so that the punch starts to contact the sheet at a constant speed of 20 mm per second. Liquid chamber hydraulic pressure (F y )=8×18000÷(0.25×π×150²)≈8.15MPa, after the punch contacts the sheet, the liquid in the liquid chamber is compressed, and the hydraulic pressure in the liquid chamber increases gradually. When the hydraulic pressure in the liquid chamber (F y ) + tensile force (F n )=1.05×33000N= 34650, gradually reduce the hydraulic pressure of the liquid chamber (F y ), hold the set value (F 0 ). As the punch continues to move down, the anti-expansion height is reduced to the set value of 0.1×150mm=1.5mm (H 0 ), the anti-expansio...

Embodiment 3

[0026] With punch diameter 150 mm, tensile force (F n )=15000N, 1 mm thick stainless steel is a specific example, the constant force when the sheet yields (F e ) is 22000N, and the critical force for sheet metal rupture (F σmax ) is 30000N. Firstly, the slider goes down in empty space, and starts to decelerate before touching the sheet, so that the punch starts to contact the sheet at a constant speed of 20 mm per second. Liquid chamber hydraulic pressure (F y )=8×15000÷(0.25×π×150²)≈6.79MPa, after the punch contacts the sheet, the liquid in the liquid chamber is compressed, and the hydraulic pressure in the liquid chamber increases gradually. When the hydraulic pressure in the liquid chamber (F y ) + tensile force (F n )=1.05×30000N= 31500N, gradually reduce the hydraulic pressure of the liquid chamber (F y ), hold the set value (F 0 ). As the punch continues to move down, the anti-expansion height is reduced to the set value of 0.1×150mm=1.5mm (H 0 ), the anti-expans...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention discloses a self-adaptive charging drawing forming method capable of preventing inverse bulging fracturing, and relates to the field of charging drawing of hydraulic drawing presses. The novel self-adaptive charging drawing forming method capable of preventing inverse bulging fracturing is provided for solving the problem that inverse bulging fracturing is prone to occurring in the charging drawing process. Before sheets are thinned to the maximum extent, inverse bulging thinning of the sheets are controlled by controlling the magnitudes of hydraulic pressure (Fy) of a liquid chamber and tensile force (Fn). When the sum of the hydraulic pressure (Fy) of the liquid chamber and the tensile force (Fn) reaches a set value (F0), the sum of the hydraulic pressure (Fy) of the liquid chamber and the tensile force (Fn) increasing as the tensile depth increases is kept at the set value (F0) by reducing the hydraulic pressure (Fy) of the liquid chamber, so that the change law that the hydraulic pressure of the liquid chamber automatically adapts to the tensile force is achieved. When the inverse bulging height drops to a set value (H0) and inverse bulging disappears, the hydraulic pressure (Fy) of the liquid chamber is increased to a set value F1 until the drawing process is completed.

Description

technical field [0001] The invention relates to a self-adaptive liquid-filled stretching forming method for preventing anti-expansion and rupture, and relates to the field of liquid-filled stretching of a stretching hydraulic machine. It solves the problem that it is difficult to accurately grasp the hydraulic pressure of the liquid chamber in the traditional liquid-filled stretching process, resulting in excessive anti-bulge thinning rate and resulting in anti-bulge cracking, and proposes a new adaptive liquid-filled stretch forming method to prevent anti-bulge cracking. Background technique [0002] In the liquid-filled stretch forming process, a liquid chamber filled with liquid is used to replace the traditional die, and the hydraulic pressure in the liquid chamber is controlled by a hydraulic system. As the punch goes down, the liquid in the liquid chamber is squeezed, resulting in an increase in the hydraulic pressure acting on the sheet. The suspended part of the pla...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): B21D26/027
CPCB21D26/027
Inventor 高一聪冯毅雄
Owner ZHEJIANG UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap