Production process for stamped parts of high mechanical resistance, through controlled electric heating

Abstract

A production process for stamped parts carried out from bales of sheets (1), a first moving robot (2), a heating device (3) with a liquid cooling unit (4), a second moving robot (4), a hydraulic press (5) with a specific molding tool, a third moving robot (6), and a conveyor belt (8), controlled by an electronic control unit. Said specific molding tool is provided with channels for cooling done through heat exchange, via water circulation, where the cooling rate is controlled by means of the liquid's flow and temperature control.

Claims

1. A production process for producing a hardened stamped part from a metal sheet through controlled electric heating, comprising transferring said sheet from a bale of metal sheets via a first moving robot to an electric heating device for heating, and after heating transferring said sheet via a second moving robot to a specific molding tool, said molding tool having a liquid cooling unit and being arranged in a hydraulic press so as to form the finished part by stamping, and after said finished part is stamped, withdrawing said finished part via a third moving robot, all of said processes being controlled by an electronic control unit, wherein said electric heating is by conduction carried out under Joule heating theory.

2. The production process according to claim 1, wherein the electric heating raises the temperature of the sheet to close to 900 C.

3. The production process according to claim 1, wherein the specific molding tool is cooled by a liquid cooling unit containing channels for cooling so as to allow heat exchange via water circulation and to promote a phase change of the microstructure of the sheet and the subsequent hardened finished part, wherein the cooling rate of the molding tool and the flow rate of the water circulation are controlled to promote the necessary change of strength for each finished part.

4. The production process according to claim 3, wherein the cooling is done at a temperature of approximately 5 C. in the channels for cooling.

5. The production process according to claim 3, wherein the cooling is provided using water generated from an ice water unit with high nominal capacity.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a top view illustration of the equipment involved in the process.

(2) FIG. 2 is a flowchart of the process, showing its operational phases.

DETAILED DESCRIPTION OF THE INVENTION

(3) According to these figures and their numerical references, the subject of this invention relates to a production process for high-strength parts through automatic controlled electric heating using a tool hardening procedure (mold and press). Said process is implemented from bales of feed sheets (1), a first moving robot (2), a heating device (3), a second moving robot (4), a specific molding tool (5) with a liquid cooling unit (6), a third moving robot (7), a hydraulic press (8). All equipment is controlled by an electronic control unit (9).

(4) In practice, the pieces, in the form of plates of various shapes (with or without defined figures), are fed to the production line automatically through bales of sheets (1), being moved by the first manipulation robot (2), which withdraws one plate at a time and deposits it in the electric heating equipment (3). This electric heating equipment (3) employs the joule heating theory raising the temperature of the plate to values around 900 C., more efficiently, with less energy expenditure and faster. The heated part is then transferred via the second manipulating robot (4) into a specific stamping tool (5) cooled by a cooling unit (6) contained in a hydraulic press (8) via a third moving robot (7), all the equipment being controlled by an electronic control unit (9).

(5) Said specific stamping tool (5) provided with a liquid cooling unit (5) containing channels for cooling, by heat exchange, via water circulation, which removes the thermal energy from the stamped product in a quick manner to promote the phase change of its microstructure and the consequent hardening of the material.

(6) The cooling is carried out at a temperature of approximately 5 C. in the channels, the water being generated from an ice water unit with high nominal capacity. The cooling rate of the stamping tool is controlled to promote the required change of strength for each product by controlling the flow rate and liquid temperature circulating in the tool.

(7) Once this step is completed, the finished product is removed from the tool by the third manipulating robot (7) and sent to the next step which may be the laser cut of the part, considering the specified geometry, or for packaging.