Bürkert helps to improve efficiency at UK car engine plant

The Nissan Sunderland car plant builds more than 500,000 cars per year. There are two parallel assembly lines building a wide variety of models that require the engine plant to keep pace with the car production lines, meaning that the engine line has to change model production on a regular basis. The engine line is supplied by the engine casting plant which uses a number of different production settings to produce three different petrol engine models which are produced and tested on site.

One of these processes is the cooling process for the freshly cast aluminium components, which was controlled by a variety of manual valves. When the time came to change the engine model, these valves had been adjusted by hand to the new settings required for the next production run. The change-over process was time consuming and the final settings often had to fine tuned. As part of a project to improve this control process, the system integrators on the site invited Brkert to suggest improvements to the current system.

Brkert's design engineers assessed the requirements of a new system and the current control infrastructure before suggesting the use of the type 2836 proportional valve which would be controlled through the type 8605 pulse-width modulated (PWM) controller. The engine component cooling process is controlled by a PLC which uses a proportional-integral-derivative (PID) controller to precisely set and monitor the flow rates of the cooling system.

The PLC produces a 4-20mA control signal for the required flow and this signal is used by the PWM controller to set the flow rate in the proportional valve. To ensure that the desired flow rate has been achieved, a flow signal is fed back to the PLC, which can then make any adjustments if required. This control loop ensures that the process is continuously monitored and therefore provides a far more accurate process.

The type 2836 solenoid control valve is a direct acting valve which can be made from brass or stainless steel, depending on the application. Capable of handling pressures up to 25 bar and available with a range of orifice and port connection sizes, the type 2836 can be designed to meet a wide range of requirements. In this case, the design expertise of the Burkert engineers ensured that the correct parameters were selected in order to deliver the required performance.

Range of options

The PWM controller can either be combined with the valve itself, or, as in this case, mounted in a separate enclosure and connected to the valve by a control wire. This range of options is designed to ensure that different environments and control arrangements can be accommodated. The input signal can be configured from a range of options including 0-20mA, 0-5V, 0-10V or 4-20mA as in this case.

This completed design has greatly improved the accuracy of the flow control system as well as significantly reducing the time taken to change the various settings to prepare for the next engine type. In doing so, the facility for applying even tighter quality control parameters has been added and the total efficiency of the engine casting line has been improved.

Craig Kerr, Area Sales Manager for Brkert, comments: "This is a great example of a systems integrator making use of the design expertise of Brkert to help them make significant improvements to the control of a fluid control system. Working with integrators, automation companies and panel builders allows us to combine knowledge to produce improved efficiency. It is often the case that the on-site engineers will identify a system that could be improved, but need some specialist technical help in making that goal a reality."

To learn more about electronic control systems from Brkert please visit www.burkert.co.uk.