The injection pressures of modern common-rail Diesel engines have increased continuously over the past few years. 2000 bar is the current standard, but this value is on the up. For this reason, the new Diesel test bench EPS 708 from Bosch, designed specifically for common-rail injectors and common-rail injection pumps, can handle tests with up to 2200 bar. Moreover, the test bench is well equipped for future developments in common-rail Diesel technology as its newly developed rail is designed for pressures of up to 2500 bar. The new rail can also be retrofitted to the tried-and-tested, high-performance Diesel test bench EPS 815, thus increasing its maximum test pressure. Bosch has also developed a new test set for Piezo injectors as an additional means of testing common-rail components in the workshop. Furthermore, Bosch has developed a world-first test procedure for determining shot-to-shot deviation. This highly accurate test allows workshops to diagnose specific faults on common-rail injectors. A new multi-clamping system for common-rail Diesel injectors in cars and commercial vehicles reduces setup times for Diesel tests.

Shorter setup times, greater safety and improved service

The new EPS 708 Diesel test bench enables workshops to test common-rail injectors and common-rail injection pumps made by Bosch and other manufacturers. Warranty evaluations are also possible for Bosch components. The test bench features an integrated cooling system, which significantly reduces the water consumption of the workshop. Conventional water cooling is also available as an option. Injection quantities are measured electronically, while the pressure feed for the pump and lubricant supply is also regulated electronically. The working area of the test bench is covered by a robust hood, providing protection from flying parts. As a result, a coupling cover for the pump is no longer required. This reduces the setup time for pump assembly even further whilst simultaneously increasing operator safety. The test bench motor cuts out immediately if the hood is raised during operation. Service intervals – for example, for test oil or filter replacement – are monitored and displayed electronically. Additionally, the self-diagnostic system of the test bench provides the workshop mechanic with reliable information concerning unscheduled servicing requirements, such as an additional filter change. Hydraulic components are protected from contamination by an integrated filter in the new high-pressure rail. The rail is also equipped with an integrated cooling system to maintain a low temperature during continuous testing.

Specific fault scenarios necessitate enhanced measuring procedure

Bosch is the first manufacturer in the world to introduce a retrofit package for workshop Diesel testing to determine variations between individual injections through shot-to-shot deviation measurement. Due to wear and tear, Diesel fuel-injection systems may eventually fail to meet the strict emission requirements of US legislation. In special cases, shot-to-shot variation must be established to identify rare or unusual faults. In comparison to conventional measuring systems, this new procedure extends the test scope to cover specific fault scenarios. The technique renders multiple tests unnecessary and avoids repeated removal and installation of the vehicle's injectors. The new measuring technology can be retrofitted to the EPS 815 and EPS 708 Diesel test benches.

Comprehensive test possibilities for Piezo common-rail injectors

Around 25 percent of common-rail Diesel engines in passenger cars are now fitted with Piezo injectors. For this reason, Bosch has released the CRI Piezo test set for the EPS 815 and EPS 708 Diesel test benches. It enables workshops to test Piezo injectors for passenger cars made by Bosch, Denso and Siemens/Continental. Testing of Delphi injectors is currently in development, though the required electronics are already integrated in the new test set. The test set contains all necessary components for comprehensive and effective Piezo injector testing. In addition to leakage tests and injection measurements for different engine operating states, the test set can also be used monitor coupler filling and check the Piezo module for insulation faults. The workshop can also perform warranty evaluations with the new test kit. Regularly updated test values are available through a subscription to the ”TestData“ CD. Test values for Diesel components of other manufacturers are available from the data provider Refdat at www.refdat.net.

New multi-clamping system for common-rail injectors

A new multi-clamping system for injectors reduces setup times and enables flexible, precise working. Up to four common-rail injectors for commercial vehicles or six solenoid or Piezo common-rail injectors for passenger cars can be clamped to the Diesel test bench at the same time. The multi-clamping system features a universal injection chamber for injectors from Bosch and other manufacturers as well as fast-action clamping. Its innovative design offers workshops many practical advantages, such as leak-free assembly of commercial vehicle injectors and cushioning of the individual injectors to protect the test pressure lines. The new common-rail clamping system can be used on the Diesel test benches EPS 708 and EPS 815.