Improving press performance for chrysler, Mexico

The Chrysler facility in Toluca consists of two plants. The first is a vast vehicle assembly shop of over 1.6 million square metres, which produces an average of 650 to 700 Dodge Journey family crossover cars each day. The second plant, for pressing body panels, was built in March 1994 and currently produces parts for two cars, the Dodge Journey and the Fiat 500. It has a total of over 200 workers and in October 2005 was the first Chrysler plant to win the Total Productive Maintenance Certificate. It has used Beloit's Unico drives systems in its giant presses since it was first opened and these are seen as contributing to both efficiency and reliability. The drives upgrade project was focused on seven presses, each of which was to be fitted with a new motor, drive and control system. The first six months of the project was given over to planning so that the two teams – Regal and Chrysler – could get to know each other. During this stage one of the key tasks was to develop a schedule of works that would mean car production could be maintained throughout the project with as little disruption to normal practices as possible. Training was also provided for the operating personnel and a long-term strategy for ensuring the provision of spare parts, well into the future, was also developed. In detail, the project included upgrading three clamping stations and three lift stations, plus associated transfer lines. All of these were fitted with Unico motors, 75 horse power units for the clamping and lifting stations, and 230 horse power motors for the transfer lines. The motors are all controlled by Unico 2450 series variable speed drives. The 2450 is a pulse width modulated (PWM) drive that can be configured for torque-, velocity- and position-control applications. Its modular design uses separate rectifier and amplifier units to provide space, cost and energy savings. The rectifier consists of a full-wave diode bridge, a bus-charging circuit, a dynamic braking circuit and a capacitor bank. The amplifier is built around a four integrated gate bipolar transistors (IGBT), four-quadrant PWM control that operates from the DC bus of the rectifier to control armature current. A separate IGBT is used to control field current. With the 2450, regenerative energy can be captured and reused, rather than dissipating it wastefully as heat through a resistor bank. A link choke provides near-unity power factor and low harmonic currents at all motor speeds. In the Chrysler project a 2490 series charging unit is installed upstream of each drive. These operate as backup units and allow continued operation without loss of control, should the power supply fail. Regal says that Unico variable speed drives are often used in pioneering and challenging projects. In many applications these high-performance drives can achieve servo drive performance levels on machinery that previously relied on mechanical or hydraulic solutions for motion control. The final result at Chrysler, Toluca was delivery of an integrated system with outstanding operational performance that Regal guarantees for at least 10 years without major interventions or technical assistance. As required, start-up was achieved without having caused any stoppage on the production line during the entire run of the project. Regal is now working on a similar but larger press modernisation project at Chrysler's plant in Saltillo, Mexico. The upgrade project was completed in conjunction with Regal de Mexico. Regal is a leading manufacturer of electrical and mechanical motion control and power generation products, serving markets throughout the world. Headquartered in Beloit, Wisconsin, the group has manufacturing, sales and service facilities throughout North America and in Mexico, Europe and Asia.