The pulse wheel

The pulse wheel, also known as a timing wheel or trigger wheel, plays an essential role in the operation of the Caterpillar C6.6 and C4.4 pumps. It's a component that interacts with the engine speed sensor to provide information about the rotational speed and position of the crankshaft. 

This information is vital for the engine control unit (ECU) to time the fuel injection and ignition processes accurately. The ERT45R control unit simulates the same feature, with very high accuracy and allows to detect the physical state of the wheel and the speed calculations, to be compared with the test bench effective speed.

The pressure control

The software's ability to continuously monitor the real-time pressure generated by the pump rotation and adjust the pressure control valve feed accordingly is essential for efficient and safe operation.

Maintaining the desired pressure level in the circuit is made possible through closed-loop control, a sophisticated control method that uses feedback to ensure the controlled variable reaches the desired value. 

Furthermore, the continuous monitoring of the ampere value consumed by the valve is a critical safety feature. If the amperage exceeds a certain threshold, the automatic protection system can be triggered to preserve the valve from potential damage. This proactive approach to safety and preservation significantly enhances the longevity and reliability of the system.

The user can increase or decrease the pressure level by simply pressing the plus (+) or minus (-) keys on the interface. This allows for precise control over the pressure level.

The software also provides the option to save up to five different pressure levels in its memory. This feature is particularly useful when the system is used in applications that require frequent switching between specific pressure levels. Instead of manually adjusting the pressure each time, the user can simply select one of the pre-set levels from the memory.

The flow rate

Fuel flow rate is a critical parameter in the operation of hydraulic systems like those found in Caterpillar C6.6 and C4.4 pumps. The software plays a vital role in determining the real fuel flow in two different lines:

• The flow feeding the rail: This is the main fuel line that carries fuel from the pump to the rail under pressure for injection into the engine.
• The flow drained by the pressure control valve: This line carries excess fuel not used during the process of preserving the constant pressure.

The software measures the flow rate in these lines at low pressure for safety reasons; these lines are provided by the dedicated module 87.11.030A. This measurement is carried out using a dedicated flowmeter, the FL400/A. This module comes with differentiated plugs for both fuel lines, ensuring accurate measurements for each. The draining line from this module leads to the test bench tank.

At any time, the operator can easily switch between the two lines using the proper handle. This simplifies the process of monitoring and adjusting the flow, making it a very useful and effective method.

The injection control

The control of fuel injection is a crucial aspect of engine operation. In this system, the software is designed to trigger the injection valve with an accurate reference for each cam. The selection process is accomplished by choosing the specific cam, with a value of zero indicating that the injection is triggered for all cams.

Two parameters, T3 and T4, are used to identify the injection characteristics. T3 controls the angular delay with an accuracy of 0.1°, while T4 controls the time duration with an accuracy of 0.01 milliseconds. This high level of precision ensures that the right amount of fuel is injected at the right time.

Interestingly, both T3 and T4 parameters are used in hexadecimal format. Hexadecimal is a base-16 number system commonly used in computing to represent binary data in a more human-readable way. Using hexadecimal format provides the highest resolution, allowing for even more precise control over the injection process.

This detailed control of the injection process plays a vital role in the overall performance and efficiency of the pump. By accurately controlling when and how much fuel is injected, the pump complies an optimized combustion, minimized emissions, and maximized fuel efficiency.

The pump timing

The proper phasing of the pump is an essential operation to warrant that the pump is synchronized with the opening and closing of the injection valves. This ensures that fuel is delivered precisely when it is needed for combustion. Incorrect phasing can lead to inefficient combustion, increased fuel consumption, and potentially damage to the engine.

Correct phasing ensures that the pump operates efficiently and effectively, delivering the right amount of fluid at the right time.

To facilitate the operator in locking the shaft in the correct position corresponding to the pump phasing, it is necessary to install a specific module on the test bench bed. This module is designed to detect the appropriate position reference that has been machined onto the half coupling - an essential component for driving the pump.

This coupling is part of the driving and mounting kit, which is a separate module which includes the mounting flange, designed to allow the lubrication of the pump, which is crucial for its operation. Lubrication reduces friction between the pump's components, thereby minimizing wear and tear and extending the lifespan of the pump.

In instances where the test bench isn't equipped to provide oil lubrication, a separate module is available to fill this role. This module (reference Marbed 8217) can be used to ensure that the pump receives the necessary lubrication for its effective operation..

The RPM sensor

The RPM (Revolutions Per Minute) sensor, is important as it plays a significant role in monitoring and controlling the speed of the pump. The connection process for this sensor has been designed to be secure and straightforward, applying original connector. This reduces the risk of connection errors, and helps maintain a stable, reliable signal from the RPM sensor

The injection valve

The original connector is applied on the bifurcation coming from the adapter cable, which serves as an extension of the basic cable. This setup ensures a robust connection to the injection valve, allowing it to function optimally.

The adapter cable, in this context, plays a crucial role by providing the necessary flexibility and adaptability to connect different injection valves that may have varying connector requirements. It not only simplifies the setup process but also ensures compatibility with future applications.