An electric starting system for a turboprop engine

Abstract

This invention provides an electric starting system for a turboprop engine, comprising: a starting relay box (106), an engine accessory (107), and an automatic fuel cut-off and over-temperature protector (108); the starting relay box (106) is used to delay disconnecting the starting control circuit and stopping the engine when receiving a starting fault signal sent by a starting check relay (102); the automatic fuel cut-off and over-temperature protector (108) is used to send a fuel cut-off command to the starting fuel cut-off solenoid valve in the engine accessory (107) according to the engine speed, exhaust temperature, and atmospheric temperature, limiting the fuel supply during engine starting, realizing the automatic fuel cut-off function during engine starting, thereby ensuring that the exhaust temperature does not exceed the limit; when the engine speed does not reach the preset speed within a specified time, or when the exhaust temperature exceeds the limit, the system controls the engine to stop. It can achieve automatic fuel cut-off and is also compatible with manual fuel cut-off operation, avoiding unnecessary engine shutdowns during starting.

Description

Technical Field

[0001] This invention belongs to the field of engine starting systems, and specifically relates to an electric starting system for a turboprop engine. Background Technology

[0002] As a key subsystem of the engine system, the engine starting system controls engine ignition and fuel supply in a timely manner, providing sufficient starting power to enable the engine to reach adequate starting speed. Controlling the ignition and fuel supply systems ensures that the engine ignites and supplies fuel at the appropriate time and speed, allowing it to start independently. Controlling the starter generator speed enables the engine to quickly reach the ignition and fuel supply speeds, shortening the starting time.

[0003] Common engine starting methods include air turbine starting and electric starting. Electric starting systems are widely used for starting various types of turbojet and turboprop engines because they are easy to automate, reliable, and simple to operate. However, electric starting systems have the following problems:

[0004] During engine startup, to prevent excessive fuel supply from causing the engine temperature to rise too high and burn out the turbine blades, the flow of fuel injectors should be controlled to reduce the amount of fuel supplied during startup. The temperature after the turbine should not exceed 750℃ during engine startup. Currently, the commonly used method for cutting off fuel is manual operation by the crew. During engine startup, the fuel cut-off button needs to be pressed repeatedly to prevent engine overheating. This operation requires a high level of technical skill from the crew; errors can affect the normal operation of the engine. Furthermore, this operation significantly increases the workload of the crew.

[0005] The starter relay box is a control device that integrates relays and contactors in the engine's electrical control system. It primarily works with an automatic timer to perform functions such as start selection, ignition control, starter fuel supply control, starter generator armature and field winding control, fuel cut-off control, engine shutdown control, and engine start-up disconnection of the generator. Furthermore, the starter relay box, in conjunction with a starter check relay, can disconnect the starter control circuit, urgently stop the engine, and output a starter fault signal to a remote data concentrator in case of engine starting failure. The starter fault signal is an alarm signal issued by the starter check relay when it detects an excessive difference in current between the left and right starter motors. A momentary difference in current between the left and right starter motors can also trigger an alarm signal; a large instantaneous difference is often unavoidable, leading to unnecessary alarm signals and engine shutdown, resulting in engine starting failure. Summary of the Invention

[0006] This invention provides an electric starting system for a turboprop engine, which can solve the problems of severe electromagnetic interference from the automatic timer and low control signal accuracy, as well as the problems of difficult fuel cutting operation by crew members during startup and engine failure and shutdown caused by excessive instantaneous left and right current difference during startup.

[0007] The present invention provides an electric starting system for a turboprop engine, comprising: a starting busbar 101, a starting check relay 102, a starting relay box 106, an engine accessory 107, and an automatic oil cut-off and over-temperature protector 108;

[0008] The starting busbar 101 is used to receive the starting power provided by the ground power vehicle 1 and transmit the starting power to the starting check relay 102 in two paths.

[0009] The start check relay 102 is used to detect the current difference between the two start power supplies transmitted by the start bus bar 101. If the current difference is greater than a preset difference, a start fault signal is output to the start relay box 106.

[0010] The starting relay box 106 is used to realize the functions of starting selection, ignition control, starting fuel supply control, starting generator armature winding and excitation winding control, fuel cut-off control, engine shutdown control, and engine starting disconnection of generator control; when receiving a starting fault signal sent by the starting check relay 102, it delays disconnection of the starting control circuit and engine shutdown.

[0011] The automatic fuel cut-off and over-temperature protector 108 is used to send a fuel cut-off command to the start-up fuel cut-off solenoid valve in the engine accessory 107 according to the engine speed, exhaust temperature and atmospheric temperature, to limit the fuel supply during engine start-up, thereby realizing the automatic fuel cut-off function during engine start-up and ensuring that the exhaust temperature does not exceed the limit; when the engine speed does not reach the preset speed within a specified time, or when the exhaust temperature exceeds the limit, the engine is controlled to stop.

[0012] Optionally, the electric starting system of the turboprop engine also includes: a starter box 103, a left starter 104, a right starter 105, and an automatic timer 109;

[0013] The start check relay 102 is also used to supply power to the left starter 104 and the right starter 105 respectively via the starter box 103 through the two starting power supplies transmitted by the starter bus bar 101, so that the left starter 104 and the right starter 105 can rotate to drive the engine turbine to work.

[0014] The automatic timer 109 is used to output control signals to the starter box 103 in a specific time sequence to control the on / off state of the excitation circuit and armature circuit in the starter box 103 and the corresponding circuit resistance changes, thereby adjusting the excitation current and armature current of the left starter 104 and the right starter 105, controlling the connection and disconnection of the aircraft engine starting circuit, thereby realizing the ground start and cold start of the engine.

[0015] Optionally, the starting relay box 106 includes: a first relay J1, a second relay J2, and a third relay J3; the first relay J1 is a time-delay relay;

[0016] The start check relay 102 detects the difference between the two starting currents output from the start busbar. When the current difference is too large, the contacts "A" and "B" of the start check relay 102 are connected, and the control signal flows from the engine control busbar 2 through the contacts "A" and "B" of the start check relay 102 to the coil of the first relay J1 in the start relay box 106, and the first relay J1 is activated.

[0017] After the first relay J1 is activated, when the duration of the control signal reaches the delay time, the signal is transmitted to the second relay J2 through the working contact of the first relay J1. The second relay J2 is used to control the on / off state of the third relay J3.

[0018] After the second relay J2 is activated, the power signal travels from the engine control busbar 2 through the working contacts of the second relay J2 to the coil of the second relay J2, causing the second relay J2 to maintain self-locking and remain in the connected state.

[0019] After the second relay J2 is activated, the control signal of the automatic timer is transmitted through the working contact of the second relay J2 to the coil of the third relay J3, and the relay J3 is activated.

[0020] After the third relay J3 is activated, the working contact circuit of the third relay J3 is disconnected, which cuts off the power supply to the control line from the engine control busbar 2 to the engine accessory 107, de-energizes the engine starting system control system, and stops the engine.

[0021] Optionally, the engine accessory 107 may further include: a start-up fuel supply solenoid valve, a stop-start solenoid valve, a hydraulic power-off switch, and an ignition coil;

[0022] The start-up check relay 102 is used to output a signal to the stop solenoid valve when the current difference is greater than a preset difference, so as to control the engine to stop during the start-up process.

[0023] The automatic timer 109 is also used to output control signals to the starter relay box 106 to control the on / off of the contactor and relay in the starter relay box 106, realize the logic conversion of the corresponding timing sequence, and then control the on / off of the starter fuel supply solenoid valve, the starter fuel cut-off solenoid valve, the ignition coil, and the hydraulic power cut-off switch to realize the fuel supply, fuel cut-off, ignition and shutdown control of the engine.

[0024] Optionally, the automatic timer 109 includes: an electrical connector 3, a power filter board 4, a control board 5, an internal main wiring board B1, a power filter board interface board XP1, and a control board interface board XP2.

[0025] The electrical connector 3 is used for the electrical connection between the internal signals of the device and the signal interfaces of other devices in the system;

[0026] The power filter board 4 includes: lightning protection and filtering circuits, which are used to meet the requirements of lightning protection, electromagnetic compatibility and power input.

[0027] The power filter board interface board XP1, the control board interface board XP2, and the internal main wiring board B1 are used for connecting signals inside the equipment.

[0028] The control board 5 includes: an input signal circuit and an output signal circuit, used for processing timing control signals;

[0029] Among the input signals of the automatic timer 109, the signals of "engine start button", "selector switch", "engine pneumatic valve" and "stop button" are transmitted to the timer in the form of hard wires. The signal of "engine start button" is in the form of "ground / floating" signal; the signals of "selector switch", "engine pneumatic valve" and "stop button" are in the form of "+28V / floating".

[0030] The output signal circuit of the automatic timer 109 is used to output low signals in a specific time sequence under the control of the processor on the control board 5, thereby turning on the engine starting circuit.

[0031] Optionally, the automatic oil cut-off and overheat protector 108 is specifically used to receive the exhaust temperature signal output by the exhaust temperature sensor, and when the exhaust temperature exceeds the limit, send a stop signal to the stop solenoid valve to control the engine to stop; and output a signal to a remote data concentrator to display the fault signal.

[0032] The automatic oil cut-off and overheat protector 108 is specifically used to determine the engine start-up time. If the engine speed does not reach the idle speed within the specified time, a stop signal is sent to the stop solenoid valve to control the engine to stop.

[0033] The automatic oil cut-off and over-temperature protector 108 is specifically used to start starting control of the engine when the engine speed signal output by the speed signal converter reaches 12% of the rated speed.

[0034] Optionally, the electric starting system for the turboprop engine also includes: a remote data concentrator 9;

[0035] The automatic oil cut-off and over-temperature protector 108 is also used to output a signal to the remote data concentrator 9 when the engine speed does not reach the preset speed within a specified time, or when the exhaust temperature exceeds the limit.

[0036] The remote data concentrator 9 is used to display the received signals.

[0037] Optionally, the surge protection circuit of the power filter board adopts a transient voltage suppressor diode (TVS).

[0038] The power filtering circuit of the power filter board is used to suppress interference signals inside the timer and external electromagnetic interference from entering the timer. A surge suppressor is used on the power line of the filtering circuit for voltage clamping, which can protect the timer when an overvoltage surge occurs.

[0039] This invention provides a turboprop engine starting system with the following advantages: During the starting process, the engine's fuel cut-off operation can be both automatic and manual, greatly reducing the operational complexity for crew members. It also features an automatic shutdown function when the engine exhaust temperature exceeds the limit, reliably ensuring the engine's normal operation. Furthermore, when the instantaneous difference in starting current between the left and right starter generators becomes excessively large during engine starting, a time-delay protection measure is implemented, effectively preventing unnecessary engine shutdowns during the starting process. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of a structure of an embodiment of the turboprop engine starting system provided by the present invention;

[0041] Figure 2 This is a schematic diagram of an embodiment of the automatic timer provided by the present invention;

[0042] Figure 3 This is a schematic diagram of the starting oil cut-off and over-temperature protector provided by the present invention;

[0043] Figure 4 This is a schematic diagram of the fault delay protection in the starting relay box provided by the present invention;

[0044] Explanation of reference numerals in the attached figures:

[0045] 1—Ground power supply vehicle; 2—Engine control busbar; 3—Electrical connector;

[0046] 4—Power supply filter board; 5—Control board; 6—Exhaust temperature sensor;

[0047] 7—Core processing platform; 8—Speed ​​signal converter; 9—Remote data concentrator;

[0048] B1—Internal main wiring board; XP1—Power filter board interface board; XP2—Control board interface board;

[0049] J1—First relay; J2—Second relay; J3—Third relay;

[0050] 101—Starting busbar; 102—Starting check relay; 103—Starter box;

[0051] 104—Left starter; 105—Right starter; 106—Starter relay box;

[0052] 107—Engine accessories; 108—Automatic oil cut-off and over-temperature protector; 109—Automatic timer. Detailed Implementation

[0053] The technical solution provided by the present invention will be explained in detail below with reference to the accompanying drawings.

[0054] Figure 1 This is a schematic diagram of a structure of an embodiment of the turboprop engine starting system provided by the present invention, as shown below. Figure 1 As shown, this embodiment of the invention provides a turboprop engine starting system, including: a starting busbar 101, a starting check relay 102, a starting box 103, a left starter 104, a right starter 105, a starting relay box 106, engine accessories 107, an automatic oil cut-off and over-temperature protector 108, and an automatic timer 109.

[0055] The starting busbar 101 is used to receive the starting power provided by the ground power vehicle 1 and transmit the starting power to the starting check relay 102 in two paths.

[0056] The start check relay 102 is used to detect the difference in current between the two start power supplies transmitted by the start bus bar. If the current difference is too large, a start fault signal will be transmitted.

[0057] The starter box 103 and the automatic timer 109 work together to automatically control the armature voltage and excitation current of the starter generator in order to gradually increase the engine speed and achieve the purpose of starting.

[0058] The starter relay box 106 is mainly used in conjunction with the automatic timer 109 to realize functions such as start selection, ignition control, start fuel supply control, start generator armature winding and excitation winding control, fuel cut-off control, engine stop control, and engine start disconnection generator control; at the same time, the starter relay box 106 can work with the start check relay 102 to delay disconnection of the start control circuit and engine stop when the engine starts in case of a fault.

[0059] The automatic timer 109 is used to control the connection and disconnection of the aircraft engine starting circuit according to a specific time sequence, thereby realizing the ground start and cold start of the engine. Since existing products cannot meet the requirements of the protocol regarding NBC protection testing, lifespan, reliability, power characteristics, electromagnetic compatibility, and lightning protection, this invention focuses on the research and development of the automatic timer 109. It replaces the mechanical timing control with a digital control circuit, improving the product's reliability and lifespan, and enhancing electromagnetic compatibility design.

[0060] The automatic fuel cut-off and overheat protection device 108 is mainly used to control the engine during ground starting to achieve automatic fuel cut-off and overheat protection shutdown. It can replace the original manual fuel cut-off and manual shutdown functions, while the original manual fuel cut-off and manual shutdown functions are still effective.

[0061] Furthermore, the turboprop engine starting system also includes a starting fuel supply solenoid valve, a starting fuel cut-off solenoid valve, a parking solenoid valve, a hydraulic power cut-off switch, and an ignition coil in engine accessory 107, which are used in conjunction with the automatic timer 109, the starting relay box 106, and the fuel cut-off and over-temperature protector 108 to realize the fuel supply, fuel cut-off, ignition, and parking control of the engine; two starter generators are used to drive the engine turbine to rotate during starting. When the engine speed reaches 42-46% of the engine's rated speed, the starter generators automatically disengage and automatically switch to generator mode.

[0062] Reference Figure 1 The engine starting current is transmitted from the ground power vehicle 1 to the starting bus bar 101 and then splits into two paths: left starting current and right starting current. These two paths of current pass through the starting check relay 102 and the starter box 103, and finally supply power to the left starter motor 104 and the right starter motor 105, respectively. The rotation of the left starter motor 104 and the right starter motor 105 drives the engine turbine to work.

[0063] The ground power vehicle 1 is used for the power output of the starting power supply circuit and the control power supply circuit during the engine starting process.

[0064] The engine starting control process is controlled by the automatic timer 109. The control signal of the automatic timer 109 is output to the starter box 103 to control the on / off of the excitation circuit and armature circuit in the starter box 103 and the change of the corresponding circuit resistance value, thereby regulating the excitation current and armature current of the left starter 104 and the right starter 105.

[0065] The control signal of the automatic timer 109 is output to the starting relay box 106 to control the on / off of the contactor and relay in the starting relay box 106, realize the logic conversion of the corresponding timing, and then control the on / off of the starting fuel supply solenoid valve, the starting fuel cut-off solenoid valve, the ignition coil, and the hydraulic power cut-off switch in the engine accessory 107.

[0066] The start check relay 102 detects the difference in starting current between the left starter generator 104 and the right starter generator 105. When the difference is too large, it outputs a start fault signal and cuts off the start control circuit, causing the engine to stop.

[0067] The automatic oil cut-off and over-temperature protector 108 outputs a signal to the engine accessory 107 for automatic oil cut-off during the starting process and to control the engine to stop when the exhaust temperature exceeds the limit.

[0068] See Figure 2 This is a schematic diagram of an embodiment of the automatic timer 109 provided by the present invention.

[0069] The automatic timer 109 includes: an electrical connector 3, a power filter board 4, a control board 5, an internal main wiring board B1, a power filter board interface board XP1, and a control board interface board XP2. Details are as follows:

[0070] The power filter board 4 is designed with lightning protection and filtering circuits to meet the requirements of lightning protection, electromagnetic compatibility and power input. The control board 5 uses a processor to perform logic judgment and processing and output timing control signals. The power filter board interface board XP1, the control board interface board XP2 and the internal main wiring board B1 are used for connecting the internal signals of the equipment. The electrical connector 3 is used for the electrical connection between the internal signals of the equipment and the signal interfaces of other equipment in the system.

[0071] The surge protection circuit of power filter board 4 uses transient voltage suppressor diodes (TVS). The working principle of a TVS diode is as follows: if the voltage exceeds the breakdown voltage marked on the diode, an avalanche occurs, providing a low-impedance path for the transient current. As a result, the transient current is diverted through the diode, bypassing the protected device, and the protected circuit remains at cutoff voltage until the voltage returns to normal. When the transient pulse ends, the TVS diode automatically returns to a high-impedance state, and the entire circuit returns to normal voltage.

[0072] The power filtering circuit of power filter board 4 can not only suppress interference signals inside the timer, but also suppress external electromagnetic interference from entering the timer. A surge suppressor is used on the power line of the filtering circuit for voltage clamping, which can protect the timer when an overvoltage surge occurs.

[0073] The control board 5 includes input signal circuits and output signal circuits, which are used for processing timing control signals.

[0074] In the input signals of the automatic timer 109, the signals such as "engine start button", "selector switch", "engine pneumatic valve" and "stop button" are transmitted to the timer in the form of hard wires. Among them, the signal of "engine start button" is in the form of "ground / floating" signal; the signals of "selector switch", "engine pneumatic valve" and "stop button" are in the form of "+28V / floating". The control circuit cannot directly receive this type of signal and must be processed by the signal processing circuit to process the "+28V / floating" signal into "ground / +5V" signal.

[0075] The function of the output signal circuit is to output low signals in a specific time sequence under the control of the processor on control board 5, thereby activating the engine starting circuit. Since low signals cannot be directly used as drive signals, they need to be converted into drive signals that can drive relays through optocouplers to control the on / off state of the relays, thereby controlling the engine starting control circuit and ignition circuit.

[0076] See Figure 3 This is a schematic diagram of an embodiment of the automatic oil cut-off and over-temperature protector 108 provided by the present invention.

[0077] The automatic oil cut-off and over-temperature protector 108 receives the exhaust temperature signal from the exhaust temperature sensor 6. When the exhaust temperature exceeds the limit, it sends a stop signal to the stop solenoid valve of the engine accessory 107 to control the engine to stop, and outputs a signal to the remote data concentrator 9 to display the fault signal.

[0078] The automatic oil cut-off and over-temperature protector 108 determines the engine start-up time. If the engine speed does not reach the idle speed within the specified time, the automatic oil cut-off and over-temperature protector 108 sends a stop signal to the stop solenoid valve of the engine accessory 107 to control the engine to stop, and outputs a signal to the remote data concentrator 9 to display the fault signal.

[0079] When the automatic fuel cut-off and over-temperature protector 108 detects that the engine speed signal output by the speed signal converter 8 reaches 12% of the rated speed, it begins to control the start of the engine. During the engine ground start-up process, the automatic fuel cut-off and over-temperature protector 108 monitors the engine speed output by the speed signal converter 8, the exhaust temperature output by the exhaust temperature sensor 6, and the atmospheric temperature output by the core processing platform 7. According to the set control algorithm, it sends a fuel cut-off command to the start-up fuel cut-off solenoid valve of the engine accessory 107 to limit the fuel supply during the engine start-up process, thereby realizing the automatic fuel cut-off function during engine start-up and ensuring that the exhaust temperature does not exceed the limit.

[0080] See Figure 4 This is a schematic diagram of the fault delay protection structure within the starting relay box 106 provided by the present invention.

[0081] The start check relay 102 detects the difference between the left and right start current outputs of the start busbar. When the current difference is too large, the contacts "A" and "B" of the start check relay 102 are connected, and the control signal flows from the engine control busbar 2 through the contacts "A" and "B" of the start check relay to the coil of the first relay J1 in the start relay box 106, and the first relay J1 is activated.

[0082] After the first relay J1 is activated, when the duration of the control signal reaches the delay time, the signal is transmitted through the working contact of the first relay J1 to the second relay J2 and the remote data concentrator 9. The second relay J2 is used to control the on / off state of the third relay J3, and the remote data concentrator 9 collects the signal and uses it to indicate the start-up fault.

[0083] After the second relay J2 is activated, the control signal travels from the engine control busbar 2 through the working contact of the second relay J2 to the coil of the second relay J2, causing the second relay J2 to maintain self-locking and remain in the connected state.

[0084] After the second relay J2 is activated, the control signal of the automatic timer 109 is transmitted to the coil of the J3 relay through the working contact of the second relay J2, and the J3 relay is activated.

[0085] After the third relay J3 is activated, the working contact circuit of the third relay J3 is disconnected, which cuts off the power supply to the control line from the engine control busbar 2 to the engine accessory 107, de-energizes the engine starting system control system, and stops the engine.

[0086] The turboprop engine starting system provided in this embodiment of the invention has the following advantages: the control signals during the starting process can be accurately output through an automatic timer; at the same time, the engine fuel cut-off operation can achieve both automatic fuel cut-off and manual fuel cut-off operation, which greatly reduces the operational complexity of the crew and has an automatic shutdown function when the engine exhaust temperature exceeds the limit, reliably ensuring the normal operation of the engine; when the instantaneous difference between the starting current of the left and right starter generators is too large during the engine starting process, a time delay protection measure is adopted to effectively avoid unnecessary shutdowns during the engine starting process.

Claims

1. An electric starting system for a turboprop engine, characterized in that, include: Starting busbar (101), starting check relay (102), starting relay box (106), engine accessories (107), and automatic oil cut-off and over-temperature protector (108); The starting busbar (101) is used to receive the starting power provided by the ground power vehicle (1) and transmit the starting power in two paths to the starting check relay (102); The start check relay (102) is used to detect the current difference between the two start power supplies transmitted by the start bus bar (101). If the current difference is greater than the preset difference, a start fault signal is output to the start relay box (106). The starting relay box (106) is used to realize the functions of starting selection, ignition control, starting fuel supply control, starting generator armature winding and excitation winding control, fuel cut-off control, engine stop control, and engine starting disconnection of generator control; when receiving the starting fault signal sent by the starting check relay (102), it delays disconnection of the starting control circuit and engine stop. The automatic oil cut-off and over-temperature protector (108) is used to send an oil cut-off command to the start-up oil cut-off solenoid valve in the engine accessory (107) according to the engine speed, exhaust temperature and atmospheric temperature, to limit the oil supply during engine start-up, realize the automatic oil cut-off function of engine start-up, so as to ensure that the exhaust temperature does not exceed the limit; when the engine speed does not reach the preset speed within a specified time, or when the exhaust temperature exceeds the limit, the engine is controlled to stop.

2. The system according to claim 1, characterized in that, Also includes: The starter box (103), the left starter (104), the right starter (105), and the automatic timer (109); The starting check relay (102) is also used to supply power to the left starter (104) and the right starter (105) respectively via the starter box (103) through the two starting power supplies transmitted by the starting bus bar (101). The left starter (104) and the right starter (105) rotate to drive the engine turbine to work. The automatic timer (109) is used to output control signals to the starter box (103) in a specific time sequence to control the on / off state of the excitation circuit and armature circuit in the starter box (103) and the change of the corresponding circuit resistance value, thereby adjusting the excitation current and armature current of the left starter (104) and the right starter (105), controlling the connection and disconnection of the aircraft engine starting circuit, thereby realizing the ground start and cold start of the engine.

3. The system according to claim 1, characterized in that, The starting relay box (106) includes: a first relay (J1), a second relay (J2) and a third relay (J3); the first relay (J1) is a time-delay relay; The start check relay (102) detects the difference between the two starting currents output by the start busbar. When the current difference is too large, the contacts "A" and "B" of the start check relay (102) are connected, and the control signal flows from the engine control busbar (2) through the contacts "A" and "B" of the start check relay (102) to the coil of the first relay (J1) in the start relay box (106), and the first relay (J1) works. After the first relay (J1) is activated, when the duration of the control signal reaches the delay time, the signal is transmitted to the second relay (J2) through the working contact of the first relay (J1). The second relay (J2) is used to control the on / off state of the third relay (J3). After the second relay (J2) is activated, the power signal travels from the engine control busbar (2) through the working contacts of the second relay (J2) to the coil of the second relay (J2), causing the second relay (J2) to maintain self-locking and remain in the connected state. After the second relay (J2) is activated, the control signal of the automatic timer is transmitted through the working contact of the second relay (J2) to the coil of the third relay (J3), and the relay (J3) is activated. After the third relay (J3) is activated, the working contact line of the third relay (J3) is disconnected, which cuts off the power supply to the control line from the engine control busbar (2) to the engine accessory (107), de-energizes the engine starting system control system, and stops the engine.

4. The system according to claim 1, characterized in that, The engine accessory (107) also includes: a start-up fuel supply solenoid valve, a stop solenoid valve, a hydraulic power-off switch, and an ignition coil; The start-up check relay (102) is used to output a signal to the stop solenoid valve when the current difference is greater than a preset difference, so as to control the engine to stop during the start-up process. The automatic timer (109) is also used to output control signals to the starter relay box (106) to control the on / off of the contactor and relay in the starter relay box (106), realize the logic conversion of the corresponding timing sequence, and then control the on / off of the starter fuel supply solenoid valve, the starter fuel cut-off solenoid valve, the ignition coil, and the hydraulic power cut-off switch to realize the fuel supply, fuel cut-off, ignition and shutdown control of the engine.

5. The system according to claim 1, characterized in that, The automatic timer (109) includes: an electrical connector (3), a power filter board (4), a control board (5), an internal main wiring board (B1), a power filter board interface board (XP1), and a control board interface board (XP2); The electrical connector (3) is used for the electrical connection between the internal signal of the device and the signal interface of other devices in the system; The power filter board (4) includes: lightning protection and filtering circuits, which are used to meet the requirements of lightning protection, electromagnetic compatibility and power input; The power filter board interface board (XP1), control board interface board (XP2), and internal main wiring board (B1) are used for connecting signals inside the equipment; The control board (5) includes: an input signal circuit and an output signal circuit, used for processing timing control signals; Among the input signals of the automatic timer (109), the signals of "engine start button", "selector switch", "engine pneumatic valve" and "stop button" are transmitted to the timer in the form of hard wires. The signal of "engine start button" is in the form of "ground / floating" signal; the signals of "selector switch", "engine pneumatic valve" and "stop button" are in the form of "+28V / floating". The output signal circuit of the automatic timer (109) is used to output low signals in a specific time sequence under the control of the processor on the control board (5) to turn on the engine starting circuit.

6. The system according to claim 4, characterized in that, The automatic oil cut-off and over-temperature protector (108) is specifically used to receive the exhaust temperature signal output by the exhaust temperature sensor, and when the exhaust temperature exceeds the limit, send a stop signal to the stop solenoid valve to control the engine to stop; and output a signal to the remote data concentrator to display the fault signal. The automatic oil cut-off and overheat protection device (108) is specifically used to determine the engine start-up time. If the engine speed does not reach the idle speed within the specified time, a stop signal is sent to the stop solenoid valve to control the engine to stop. The automatic oil cut-off and over-temperature protector (108) is specifically used to start the engine starting control when the engine speed signal output by the speed signal converter reaches 12% of the rated speed.

7. The system according to claim 6, characterized in that, Also includes: remote data concentrator (9); The automatic oil cut-off and over-temperature protector (108) is also used to output a signal to the remote data concentrator (9) when the engine speed does not reach the preset speed within a specified time, or when the exhaust temperature exceeds the limit. The remote data concentrator (9) is used to display the received signals.

8. The system according to claim 5, characterized in that, The surge protection circuit of the power filter board uses transient voltage suppressor diodes (TVS). The power filtering circuit of the power filter board is used to suppress interference signals inside the timer and external electromagnetic interference from entering the timer. A surge suppressor is used on the power line of the filtering circuit for voltage clamping, which can protect the timer when an overvoltage surge occurs.

Images