1 Title of the Invention
Ventilation, Starting and Shutdown Control System for Turbo-Shaft
Engine.
2 Field of the Invention
The present invention relates to control mechanism in general and starting
and shutdown system in particular, for Turbo shaft engines for the
helicopter Industry‘
3 Background of the Invention
Ventilation, Starting and Shutdown Control System for Turbo-Shaft Engine
are used in helicopters to perform operations that result in the proper
function of the helicopter during flight. For each operation there is precise
timing and sequence of steps to follow‘ Timing for staffing varies
depending on the temperature. i.e., the starting timing is not same when
the engine is used in Rajasthan, Kerala, and Ladakh, Even when afi
aircraft operates on different locatibns, timing must be set manually and it
may take significant effort and time to tune the unit. This may lead to delay
in aircraft operations and can also cause safety risks. Hence, a new
system developed will solve this problerh by implementing automatic
precise timing control with respect to exposed temperature with the help of
a microcontroller-based system.
4 Brief Summary of the Invention
The Ventilation, Starting and Shutdown Control System for Turbo-Shaft
Engine, is a microcontroller-based control system that controls the timing
sequence for the said functionalities. It uses hermetically sealed high
temperature relays to switch and control the electrical channels for
functioning of the sequences. This system can provide precise time period
for the sequences of engine starting, shut Down and ventilation. It can
control the time interval for ignition sequence of the engine depending on
the ambient temperature of the environment in which the system exists.
This system can store the previous sequence in case of a power failure
and can continue operating in the previous sequence in case of power ON
after a power failure. Additional functionalities can be incorporated in this
system with a firmware upgrade,
5 Detail Description of the Drawings
Figure 1 illustrates the isometric View of the Ventilation, Staining and
Shutdown Control System for Turbo-Shaft Engine and depicts all the components explicitly.
6 Detail Description of the Invention .
The Ventilation, Starting and Shutdown Control System for,Turbo-Shaft
Engine is a micro controller-based control system that controls the«timing
sequence for the said functionalities. It is installed firmly in the control box
of helicopter engines.
Referring to Figure, it is primarily composed of a controller PCB [06], an
aluminium frame [1] and Mo electromagnetically relays [O7] & [081A
The controller PCB [06] is mounted on the aluminium frame [1] using
M3x8 CHD Screws [12] & M3x6 H_ex Spacers [17] at 6 mounting points.
Controller PCB [06] takes control| signals from the pilot's operations as
inputs'. These inputs are sensed as interrupts by the microcontroller, which
are level shifted via reIayS'which are part of controller PCB [06]. The
necessary delays, namely 555, 335 and 185 are provided by internal timer
routines run by micro controller. The main power supply of 24V from the ,
source battery in the 'helicopter is ‘stepped'down to desired levels for
micro controller and relay driver present in controller PCB [06], The time
period‘for ignition sequence is calculated based on the ambient
(temperature of the system. The temperature is measured by a
temperature sensor IC on the controller PCB [06] and is~provided as. an
input for the time period calculation. The Filters [09] are mounted on the
Filter clamp [3] and fixed to the aluminium frame using M3x8 CHD screws
[12]. The filters give protection against transient noises in the power
supply input in both positive and ground paths‘ The Relay A [7] and Relay
M [8] are mounted on the ECU frame using M3 Nuts [14]‘ Relay A is used
for the for the proper functioning of the control system durifig its shutdown
and ventilation procedures‘ The ’accessories to be energized and deenergized
during the shutdown and ventilation procedure are done so via
the connections of Relay A, Relay M is used for the proper functioning of
the control system during it starting and ignition procedures. The
accessories t6 be energized and de-energized during the starting and
ignition procedures are done so via the connections of Relay M. The
power resistors [10] are fixed on the resistor clamp [2] using M2.5x6 CHD
Screws [15] and M25 Nuts [16], and the resistor clamp is mounted on the
aluminium frame using M3x8 CHD screws [12] and M3 Nuts {14]. The
Relay A and M are energizer because of the voltage drop across the
power resistor, which is connected to the ground. The value of the resistor
is chosen in such a way that it is equivalent to the coil resistor of Relay A
and M It also functions as Anti-condensation heater in case of éold
temperatures in the environment of the control system. The PCB relay [18]
is mounted on the ECU frame using M3x8 CHD screws [12]. It provides
the connections for the ignition stage to function properly‘ The accessories
to be energized during the ignition procedure are done.so via the
connections made through the PCB relay. The Rubber washer [4] and
Metal insert [5] are installed for mounting the system in control box of
helicopter engine. All M3x8 CHD screws [12] are supported by M3 Spring
Washers [13]. The unit consists of a male D-Connector [19] of 25 pins
which is mouthed on the aluminium frame using M3x14 CSK Screw (.11).‘|t
is used to interface the control system with the Turbo-Shaft engine. The
power supply. input and output signals required for the functioning of the
system are transferred via this connector‘
We Claim,
1‘ A system for controlling. the ventilation, starting and shutdown
5 sequence of Turbo-shaft engine comprising:
a Controlled PCB [06], filters [9], power resistors [10] and relays [7], [8]
& [18].
2. The system as claimed in claim 1 has a D-Connector interface [19] and
is mounted on an aluminium frame [1) with the help of Screws.