Coupling box mode selection control system for fire trucks

Abstract

The application discloses a coupling box mode selection control system for a fire engine, wherein the working modes of the vehicle include a double-engine driving running mode, a single-engine driving running mode, a running water spraying mode and a parking water spraying mode; when the double-engine driving running mode is selected, two power paths of the engine with the transmission D1+T1 and D2+T2 are converged through the coupling box and drive the vehicle together; when the single-engine driving running mode is selected, the power path of the engine with the transmission D1+T1 or D2+T2 drives the vehicle after the coupling box, and the other engine idles or is turned off; when the running water spraying mode is selected, the power path of the engine with the transmission D1+T1 or D2+T2 drives the vehicle after the coupling box, and the power path of the other engine with the transmission D1+T1 or D2+T2 is output to the water pump after the coupling box; when the parking water spraying mode is selected, the power path of the engine with the transmission D1+T1 or D2+T2 is output to the water pump after the coupling box, and the other engine idles or is turned off, and the application has the advantages of being capable of realizing the switching of multiple working modes and the good coordination of two sets of power sources.

Description

Technical Field

[0001] This invention relates to the field of fire protection technology, specifically a mode selection control system for a coupling box used in fire trucks. Background Technology

[0002] Airport fire trucks are key emergency equipment for ensuring aviation safety. They are specifically designed to prevent and extinguish aircraft fires and to provide rapid rescue to passengers and crew in emergency situations.

[0003] To meet increasingly stringent rescue standards, 8x8-drive airport fire trucks have become the mainstream. Compared to traditional models, 8x8 fire trucks have superior acceleration performance and larger liquid carrying capacity, combining the high mobility of 4x4 quick-adjustment vehicles with the large liquid carrying capacity of 6x6 main vehicles.

[0004] Currently, 8×8 airport fire trucks generally adopt a power system architecture with dual engines and dual transmissions. The output of the two power sources is integrated through a coupling box to drive the vehicle, thereby meeting its power requirements for extreme acceleration performance and complex operating conditions.

[0005] In this technological context, airport fire trucks also need to have multiple functions such as water spraying while driving and water spraying while parked. The mode control method of the coupling box has become the core key technology of the entire system. How to achieve the switching of multiple modes, ensure the rapid, smooth and seamless switching between modes, and ensure the high efficiency of power coupling to improve the overall performance of the fire truck are key technical issues that urgently need to be studied in depth. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a fire truck coupling box mode selection control system that can achieve multiple working mode switching and good coordination between two power sources.

[0007] The technical solution adopted by this invention to solve its technical problem is:

[0008] A coupling box mode selection control system for fire trucks, characterized in that: the vehicle operating modes include dual-engine drive mode, single-engine drive mode, driving water spraying mode, and parking water spraying mode;

[0009] When the dual-engine drive mode is selected, the two power sources, engine with transmission D1+T1 and engine with transmission D2+T2, are combined through the coupling box to drive the vehicle together.

[0010] When the single-engine drive mode is selected, the power from the engine with transmission D1+T1 or the engine with transmission D2+T2 drives the vehicle through the coupling box, while the other engine is idling or off.

[0011] When the vehicle is selected to operate in water-spraying mode, the power from either the engine with transmission D1+T1 or the engine with transmission D2+T2 drives the vehicle through the coupling box, while the power from the other engine with transmission D1+T1 or the engine with transmission D2+T2 is output to the water pump for firefighting operations through the coupling box.

[0012] When the vehicle is in parking water pumping mode, the power of one of the two engines, D1+T1 and D2+T2, is output to the water pump via the coupling box for fire fighting, while the other engine is in idling or off state.

[0013] By coordinating two power sources, multiple working modes can be switched according to specific working conditions, which can meet both the requirements for vehicle acceleration and firefighting, realize the use requirements of fire trucks in various working conditions, and greatly improve the efficiency of operation and firefighting.

[0014] The vehicle operating modes of this invention also include neutral and traction modes. When the vehicle needs to be towed, neutral and traction modes are selected, and the connection between the engine and transmissions D1+T1 and D2+T2 is disconnected from the coupling box. Transmissions T1 and T2 are then put back into neutral for easy towing.

[0015] The coupling box of the present invention is provided with clutch C1, clutch C2 and clutch C3;

[0016] The clutch C1 is used to control the engagement or disengagement of one of the engine-driven transmission D1+T1 and the engine-driven transmission D2+T2 with the coupling box to switch the power to the water pump on or off.

[0017] The clutch C2 is used to control the engagement or disengagement of one of the engine-driven transmissions D1+T1 and D2+T2 with the coupling box to switch power to the vehicle drive shaft.

[0018] The clutch C3 is used to control the engagement or disengagement of one of the engine-driven transmissions D1+T1 and D2+T2 with the coupling box to switch power to the vehicle drive shaft.

[0019] By controlling the engagement and disengagement of the clutch, the mode switching can be achieved. The switching method is simple, the functions are integrated, and it can meet the switching requirements of various complex working conditions.

[0020] The coupling box of the present invention is provided with four pressure ports, including pressure port ①, pressure port ②, pressure port ③ and pressure port ④;

[0021] The pressure port ① and pressure port ② work together to control the engagement and disengagement of clutch C2;

[0022] The pressure port ③ controls the engagement and disengagement of clutch C1;

[0023] The pressure port ④ controls the engagement and disengagement of clutch C3;

[0024] The clutch is controlled by air pressure, resulting in a rapid response and smooth switching.

[0025] When pressure port ① supplies air and pressure port ② does not supply air, clutch C2 engages; when pressure port ① does not supply air and pressure port ② supplies air, clutch C2 disengages; or, when pressure port ① supplies air and pressure port ② does not supply air, clutch C2 disengages; when pressure port ① does not supply air and pressure port ② supplies air, clutch C2 engages.

[0026] When pressure port ③ supplies air, clutch C1 engages; when pressure port ③ does not supply air, clutch C1 disengages. Alternatively, when pressure port ③ supplies air, clutch C1 disengages; when pressure port ③ does not supply air, clutch C1 engages.

[0027] When pressure port ④ supplies air, clutch C3 engages; when pressure port ④ does not supply air, clutch C3 disengages. Alternatively, when pressure port ④ supplies air, clutch C3 disengages; when pressure port ④ does not supply air, clutch C3 engages.

[0028] Clutch C2 is controlled by dual pressure ports. Whether engaging or disengaging, it is actively completed by air pressure, which effectively avoids the problems of incomplete disengagement or weak engagement that exist in existing systems where air is supplied in one direction and spring resets in the other.

[0029] The clutch C3 described in this invention is a normally closed clutch, and the clutches C1 and C2 are normally open clutches.

[0030] The coupling box of the present invention is provided with four detection switches for feedback on the engagement or disengagement status of the clutch. The switches include switch K1, switch K2, switch K3 and switch K4.

[0031] The switch K1 provides feedback on the engagement or disengagement status of the clutch C1;

[0032] The switch K2 and switch K3 are in the state of feedback clutch C2 being engaged or disengaged;

[0033] The switch K4 provides feedback on the engagement or disengagement status of the clutch C3;

[0034] By detecting the clutch status through a switch, real-time monitoring of the entire power coupling process can be achieved.

[0035] When clutch C1 is engaged, switch K1 outputs a first signal; when clutch C1 is disengaged, switch K1 outputs a second signal or does not output a signal; or, when clutch C1 is disengaged, switch K1 outputs a first signal; when clutch C1 is engaged, switch K1 outputs a second signal or does not output a signal.

[0036] When clutch C2 is engaged, switch K2 outputs the first signal, and switch K3 outputs the second signal or no signal. When clutch C2 is disengaged, switch K2 outputs the second signal or no signal, and switch K3 outputs the first signal; or, when clutch C2 is disengaged, switch K2 outputs the first signal, and switch K3 outputs the second signal or no signal; when clutch C2 is engaged, switch K2 outputs the second signal or no signal, and switch K3 outputs the first signal.

[0037] When clutch C3 is engaged, switch K4 outputs a first signal; when clutch C3 is disengaged, switch K4 outputs a second signal or no signal. Alternatively, when clutch C3 is disengaged, switch K4 outputs a first signal; when clutch C3 is engaged, switch K4 outputs a second signal or no signal. The state of clutch C2 is detected by dual switches, improving the system's safety, reliability, and accuracy of state judgment.

[0038] In this invention, when switching from dual-engine drive mode to driving water mode, the vehicle speed is first reduced, clutch C2 is disengaged, and one of the engine-driven transmissions D1+T1 and D2+T2 is disconnected from the coupling box.

[0039] The system detects vehicle speed, water pump speed, and the speed of one of the input drive shafts, namely engine with transmission D1+T1 and engine with transmission D2+T2. When the difference between the input drive shaft speed and the water pump speed is less than the set value, clutch C1 is engaged.

[0040] The engine and transmission D1+T1 and the engine with transmission D2+T2, one of which transmits power to the water pump via the coupling box for water pump fire fighting operations;

[0041] After the operation is completed, disengage clutch C1;

[0042] It enables firefighting operations during driving, and allows for smooth mode switching, eliminating shocks, protecting the transmission system, and improving reliability;

[0043] To switch from driving water-spraying mode to dual-engine drive mode, first disengage clutch C1, synchronize the speeds of both ends of clutch C2, and when the speed difference between the two ends of clutch C2 is less than the set value, engage clutch C2.

[0044] The power from the engine with transmission D1+T1 and the engine with transmission D2+T2 is combined through the coupling box to drive the vehicle together.

[0045] It achieves smooth mode switching, eliminates engagement shock, protects the transmission system, and improves reliability.

[0046] During the dual-engine drive mode described in this invention, the output power and speed of the two engines are synchronously adjusted according to the vehicle accelerator pedal opening value and vehicle speed to maintain their consistent operating state.

[0047] The vehicle's gear shifter controls the two transmissions to switch gears synchronously, ensuring that the two transmissions are in the same gear and the switching time is consistent.

[0048] This allows for the coordinated and smooth output of power from two independent power sources, ensuring stable vehicle operation while protecting the transmission system and improving reliability.

[0049] The beneficial effects of this invention are as follows: by coordinating two power sources, multiple working modes can be switched according to specific working conditions, which can meet both the requirements for vehicle acceleration and fire fighting, realize the use requirements of fire trucks under various working conditions, and greatly improve the efficiency of operation and fire fighting. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the coupling box and shaft mating structure of the present invention.

[0051] Figure 2 This is a schematic diagram of the coupling box and shaft from another angle according to the present invention.

[0052] Figure 3 This is a schematic diagram of the power transmission of the present invention.

[0053] Figure 4 This is a schematic diagram of the pressure port and switching logic of the coupling box under different working modes of the present invention.

[0054] Figure 5 This is a flowchart illustrating the control process for switching from dual-engine drive mode to water-spraying mode in this invention.

[0055] Figure 6 This is a flowchart illustrating the control process for switching from the vehicle's water-spraying mode to the dual-engine drive mode in this invention.

[0056] Figure label:

[0057] Engine with transmission D1+T1 input drive shaft-101; Engine with transmission D2+T2 input drive shaft-102;

[0058] PTO drive shaft-2;

[0059] Output front drive shaft-301, output rear drive shaft-302;

[0060] Switches K1-401, K2-402, K3-403; K4-404;

[0061] Pressure port ①-501, pressure port ②-502, pressure port ③-503, pressure port ④-504;

[0062] Coupling box-6. Detailed Implementation

[0063] The present invention will now be described in conjunction with the accompanying drawings and embodiments.

[0064] Example 1:

[0065] A coupling box mode selection control system for fire trucks, wherein the vehicle operating modes include dual-engine drive mode, single-engine drive mode, driving water spraying mode, parking water spraying mode, neutral and traction modes;

[0066] The current operating mode of the vehicle is determined based on the operator's signals from the airport fire truck. A dual-engine drive mode is selected, where the power from both engines (D1+T1 and D2+T2) is combined via coupling box 6 to drive the vehicle. In this embodiment, during dual-engine drive mode, the output power and speed of the two engines are synchronously adjusted according to the accelerator pedal opening and vehicle speed to maintain consistent operating conditions. The vehicle's gear shifter controls the two transmissions to synchronously switch gears, ensuring consistent gear positions and shift times. This achieves coordinated and smooth power output from the two independent power sources, guaranteeing stable vehicle operation, protecting the transmission system, and improving reliability.

[0067] When the single-engine drive mode is selected, the power from the engine with transmission D1+T1 or the engine with transmission D2+T2 drives the vehicle through coupling box 6, while the other engine is idling or off.

[0068] When the vehicle is selected to operate in the water-spraying mode, the power from one of the engine with transmission D1+T1 and the engine with transmission D2+T2 drives the vehicle through the coupling box 6, and the power from the other of the engine with transmission D1+T1 and the engine with transmission D2+T2 is output to the water pump for fire fighting operations through the coupling box 6.

[0069] When the parking water pumping mode is selected, the power of one of the two engines, namely the engine with transmission D1+T1 and the engine with transmission D2+T2, is output to the water pump for fire fighting after passing through the coupling box 6, while the other engine is in an idling or off state.

[0070] When the vehicle needs to be towed, select neutral and towing mode. Both engine-driven transmission D1+T1 and engine-driven transmission D2+T2 are disconnected from coupling box 6, and transmissions T1 and T2 are put back into neutral.

[0071] By coordinating two power sources, multiple working modes can be switched according to specific working conditions, which can meet both the requirements for vehicle acceleration and fire protection.

[0072] In this embodiment, when the driving water pumping mode and the parking water pumping mode are selected, the engine drives the transmission D1+T1 to work with the water pump.

[0073] The coupling box is equipped with clutches C1, C2 and C3;

[0074] The clutch C1 is used to control the engagement or disengagement of one of the engine-driven transmission D1+T1 and the engine-driven transmission D2+T2 with the coupling box 6 to switch the power to the water pump on or off.

[0075] The clutch C2 is used to control the engagement or disengagement of one of the engine-driven transmissions D1+T1 and D2+T2 with the coupling box 6 to switch power to the vehicle drive shaft.

[0076] The clutch C3 is used to control the engagement or disengagement of one of the engine-driven transmissions D1+T1 and D2+T2 with the coupling box 6 to switch the power to the vehicle drive shaft.

[0077] By controlling the engagement and disengagement of the clutch, the mode switching can be achieved. The switching method is simple, the functions are integrated, and it can meet the switching requirements of various complex working conditions.

[0078] This embodiment is as shown in the appendix. Figure 1 -Appendix Figure 3 As shown, clutch C1 is used to control the engagement or disengagement of the engine-driven transmission D1+T1 with the transmission mechanism inside the coupling box 6 to switch the power to the water pump; in this embodiment, the transmission mechanism inside the coupling box is connected to the PTO drive shaft 2, and the PTO drive shaft is connected to the water pump impeller shaft; clutch C2 is used to control the engagement or disengagement of the engine-driven transmission D1+T1 with the transmission mechanism inside the coupling box to switch the power to the vehicle drive shaft; clutch C3 is used to control the engagement or disengagement of the engine-driven transmission D2+T2 with the transmission mechanism inside the coupling box to switch the power to the vehicle drive shaft.

[0079] As attached Figure 1 As shown, the coupling box 6 is provided with four pressure ports, including pressure port ①501, pressure port ②502, pressure port ③503 and pressure port ④504.

[0080] The pressure port ①501 and pressure port ②502 work together to control the engagement and disengagement of clutch C2;

[0081] The pressure port ③503 controls the engagement and disengagement of clutch C1;

[0082] The pressure port ④504 controls the engagement and disengagement of clutch C3;

[0083] The clutch is controlled by air pressure, resulting in a rapid response and smooth switching.

[0084] When pressure port ①501 supplies air and pressure port ②502 does not supply air, clutch C2 engages; when pressure port ①501 does not supply air and pressure port ②502 supplies air, clutch C2 disengages; or, when pressure port ①501 supplies air and pressure port ②502 does not supply air, clutch C2 disengages; when pressure port ①501 does not supply air and pressure port ②502 supplies air, clutch C2 engages.

[0085] When pressure port ③503 supplies air, clutch C1 engages; when pressure port ③503 does not supply air, clutch C1 disengages. Alternatively, when pressure port ③503 supplies air, clutch C1 disengages; when pressure port ③503 does not supply air, clutch C1 engages.

[0086] When pressure port ④504 supplies air, clutch C3 engages; when pressure port ④504 does not supply air, clutch C3 disengages. Alternatively, when pressure port ④504 supplies air, clutch C3 disengages; when pressure port ④504 does not supply air, clutch C3 engages.

[0087] Clutch C2 is controlled by dual pressure ports. Whether engaging or disengaging, it is actively completed by air pressure, which effectively avoids the problems of incomplete disengagement or weak engagement that exist in existing systems where air is supplied in one direction and spring resets in the other.

[0088] In this embodiment, clutch C3 is a normally closed clutch, and clutches C1 and C2 are normally open clutches; the choice between normally open and normally closed clutches can be set according to specific requirements.

[0089] In this embodiment, when pressure port ①501 supplies air and pressure port ②502 does not supply air, clutch C2 is engaged; when pressure port ①501 does not supply air and pressure port ②502 supplies air, clutch C2 is disengaged. When pressure port ③503 supplies air, clutch C1 is engaged; when pressure port ③503 does not supply air, clutch C1 is disengaged. When pressure port ④504 supplies air, clutch C3 is disengaged; when pressure port ④504 does not supply air, clutch C3 is engaged.

[0090] The coupling box 6 is equipped with four detection switches for feedback on the clutch engagement or disengagement status. The detection switches include switch K1 401, switch K2 402, switch K3 403 and switch K4 404.

[0091] The switch K1 provides feedback on the engagement or disengagement status of the clutch C1;

[0092] The switch K2 and switch K3 are in the state of feedback clutch C2 being engaged or disengaged;

[0093] The switch K4 provides feedback on the engagement or disengagement status of the clutch C3;

[0094] By detecting the clutch status through a switch, real-time monitoring of the entire power coupling process can be achieved.

[0095] When clutch C1 is engaged, switch K1 outputs a first signal; when clutch C1 is disengaged, switch K1 outputs a second signal or no signal. Alternatively, when clutch C1 is disengaged, switch K1 outputs a first signal; when clutch C1 is engaged, switch K1 outputs a second signal or no signal.

[0096] When clutch C2 is engaged, switch K2 outputs the first signal, and switch K3 outputs the second signal or no signal. When clutch C2 is disengaged, switch K2 outputs the second signal or no signal, and switch K3 outputs the first signal; or, when clutch C2 is disengaged, switch K2 outputs the first signal, and switch K3 outputs the second signal or no signal; when clutch C2 is engaged, switch K2 outputs the second signal or no signal, and switch K3 outputs the first signal.

[0097] When clutch C3 is engaged, switch K4 outputs a first signal; when clutch C3 is disengaged, switch K4 outputs a second signal or no signal. Alternatively, when clutch C3 is disengaged, switch K4 outputs a first signal; when clutch C3 is engaged, switch K4 outputs a second signal or no signal.

[0098] The status of clutch C2 is detected by dual switches, which improves the safety, reliability and accuracy of status judgment of the system.

[0099] In this embodiment, when clutch C1 is engaged, switch K1 outputs a first signal; when clutch C1 is disengaged, switch K1 does not output a signal. When clutch C2 is disengaged, switch K2 outputs a first signal and switch K3 does not output a signal. When clutch C2 is engaged, switch K2 does not output a signal and switch K3 outputs a first signal. When clutch C3 is disengaged, switch K4 outputs a first signal; when clutch C3 is engaged, switch K4 does not output a signal.

[0100] In this embodiment, the detection switch provides feedback on the clutch engagement or disengagement status by outputting a signal or not outputting a signal. It can also provide feedback on the clutch engagement or disengagement status by outputting a high level or a low level, which can be set as needed.

[0101] This implementation example is attached. Figure 4 As shown, the pressure port and switch status are listed for each working mode.

[0102] Dual-engine drive mode: Pressure port ① supplies air, pressure ports ②, ③, and ④ do not supply air; switches K1 and K3 output the first signal, while switches K2 and K4 do not output a signal;

[0103] The specific control logic is as follows: when the valve at pressure port ③ is closed, no air is supplied to pressure port ③, clutch C1 is in the disengaged state, and the power of the engine driving the transmission D1+T1 will not be transmitted to the water pump through the PTO drive shaft 2. At this time, switch K1 outputs the first signal to feedback that clutch C1 is in the disengaged state.

[0104] When the valve at pressure port ① is open and the valve at pressure port ② is closed, air is supplied to pressure port ① and not to pressure port ②. Clutch C2 is engaged, and the power from the engine to the transmission D1+T1 is connected to the vehicle drive shaft via the coupling box. Switch K2 does not output an electrical signal and switch K3 outputs the first signal, indicating that clutch C2 is engaged.

[0105] The valve at pressure port ④ is closed, no air is supplied to pressure port ④, clutch C3 is engaged, the engine drives transmission D2+T2 and is connected to the vehicle drive shaft via the coupling box, switch K4 does not output an electrical signal, and feedback clutch C3 is engaged.

[0106] In dual-engine drive mode, the power from the engine with transmission D1+T1 and the engine with transmission D2+T2 is combined through the coupling box and then transmitted to the vehicle drive shafts (output front drive shaft 301 and output rear drive shaft 302) to drive the vehicle.

[0107] Engine with transmission D1+T1 single-engine drive mode: Pressure port ① and pressure port ④ supply air, pressure port ② and pressure port ③ do not supply air, switch K1, switch K3 and switch K4 output the first signal, switch K2 does not output a signal;

[0108] The specific control logic is as follows: when the valve at pressure port ③ is closed, no air is supplied to pressure port ③, clutch C1 is in the disengaged state, and the power of the engine driving the transmission D1+T1 will not be transmitted to the water pump. At this time, switch K1 outputs the first signal to feedback that clutch C1 is in the disengaged state.

[0109] When the valve at pressure port ① is open and the valve at pressure port ② is closed, air is supplied to pressure port ① and not to pressure port ②. Clutch C2 is engaged, and the power from the engine to the transmission D1+T1 is connected to the vehicle drive shaft via the coupling box. Switch K2 does not output an electrical signal and switch K3 outputs the first signal, indicating that clutch C2 is engaged.

[0110] When the valve at pressure port ④ is opened, air is supplied to pressure port ④, clutch C3 is disengaged, and the power from the engine to transmission D2+T2 will not be transmitted to the vehicle drive shaft through the coupling box. Switch K4 outputs the first signal, indicating that clutch C3 is in the disengaged state.

[0111] In the single-engine drive mode with engine and transmission D1+T1, the power of engine and transmission D1+T1 is transmitted to the vehicle drive shaft through the coupling box to drive the vehicle, while engine D2 is in idle or off state.

[0112] Engine with transmission D2+T2 single-engine drive mode: Pressure port ② supplies air, pressure ports ① and ④ do not supply air, switch K2 outputs the first signal, and switches K3 and K4 do not output signals.

[0113] The specific control logic is as follows: the valve at pressure port ① is closed and the valve at pressure port ② is open. Pressure port ① does not supply air, pressure port ② supplies air, clutch C2 is disengaged, the power of the engine and transmission D1+T1 will not be transmitted to the vehicle drive shaft through the coupling box, switch K2 outputs the first signal and the switch does not output a signal, and the feedback clutch C2 is in the disengaged state.

[0114] The valve at pressure port ④ is closed, no air is supplied to pressure port ④, clutch C3 is engaged, the power from the engine to transmission D2+T2 is transmitted to the vehicle drive shaft through the coupling box to drive the vehicle, switch K4 does not output a signal, and feedback clutch C3 is engaged.

[0115] In the single-engine drive mode with engine and transmission D2+T2, the power of engine and transmission D2+T2 is transmitted to the vehicle drive shaft through the coupling box to drive the vehicle. Engine D2 is in an idling or off state, and the engagement or disengagement state of clutch C1 is not required.

[0116] Water pumping mode: Pressure ports ② and ③ supply air, pressure ports ① and ④ do not supply air, switch K2 outputs the first signal, switches K1, K3, and K4 do not output signals;

[0117] The specific control logic is as follows: the valve at pressure port ③ is opened, air is supplied to pressure port ③, clutch C1 is engaged, the power of the engine driving the transmission D1+T1 is transmitted to the water pump through the coupling box, switch K1 does not output a signal, and feedback clutch C1 is in the engaged state.

[0118] When the valve at pressure port ① is closed and the valve at pressure port ② is open, pressure port ① is not supplied with air and pressure port ② is supplied with air, clutch C2 is disengaged, and the power of the engine and transmission D1+T1 will not be transmitted to the vehicle drive shaft through the coupling box. Switch K2 outputs the first signal and switch K3 does not output a signal, indicating that clutch C2 is in the disengaged state.

[0119] When the valve at pressure port ④ is closed, no air is supplied to pressure port ④, clutch C3 is engaged, and the power from the engine to transmission D2+T2 is transmitted to the vehicle drive shaft via the coupling box to drive the vehicle. Switch K4 does not output a signal, and feedback clutch C3 is in the engaged state.

[0120] In the driving water-spraying mode, the power from the engine and transmission D2+T2 is transmitted to the vehicle drive shaft via the coupling box to drive the vehicle, while the power from the engine and transmission D1+T1 is transmitted to the water pump via the coupling box for firefighting operations.

[0121] Parking water supply mode: Pressure port ② and pressure port ③ supply air, pressure port ① does not supply air, switch K2 outputs the first signal, and switches K1 and K3 do not output signals.

[0122] The specific control logic is as follows: when pressure port ③ valve is opened, pressure port ③ supplies air, clutch C1 is engaged, and the power from the engine to transmission D1+T1 is transmitted to the water pump through the coupling box. Switch K1 does not output a signal, and feedback clutch C1 is in the engaged state.

[0123] When the valve at pressure port ① is closed and the valve at pressure port ② is open, pressure port ① does not supply air and pressure port ② supplies air, clutch C2 disengages, and the power from the engine to the transmission D1+T1 will not be transmitted to the vehicle drive shaft via the coupling box.

[0124] In the parking water-spraying mode, the power from the engine and transmission D1+T1 is transmitted to the water pump via the coupling box for firefighting operations. The engine D2 is in an idling or off state, and the engagement or disengagement of the clutch C2 is not required.

[0125] Neutral and traction modes: Pressure ports ② and ④ supply air, pressure port ① does not supply air, switches K2 and K4 output the first signal, and switch K3 does not output a signal;

[0126] The specific control logic is as follows: the valve at pressure port ① is closed and the valve at pressure port ② is open. Pressure port ① does not supply air and pressure port ② supplies air. Clutch C2 is disengaged. The power of the engine and transmission D1+T1 will not be transmitted to the vehicle drive shaft through the coupling box. Switch K2 outputs the first signal and switch K3 does not output a signal, and the feedback clutch C2 is in the disengaged state.

[0127] When the valve at pressure port ④ is opened, air is supplied to pressure port ④, clutch C3 is disengaged, and the power from the engine to transmission D2+T2 will not be transmitted to the vehicle drive shaft through the coupling box. Switch K4 outputs the first signal, indicating that clutch C3 is in the disengaged state.

[0128] In neutral and traction modes, clutches C2 and C3 are disengaged, and the power from the engine to transmissions D1+T1 and D2+T2 is not transmitted to the vehicle drive shaft via the coupling box, which facilitates traction. In this embodiment, in this mode, engines D1 and D2 are in idle and off state, and transmissions T1 and T2 are engaged in neutral. The state of clutch C1 is not required.

[0129] In this embodiment, when switching from dual-engine drive mode to driving water mode, the vehicle speed is reduced, clutch C2 is disengaged, and the engine, transmission D1+T1, and coupling box are disconnected.

[0130] Detect vehicle speed, water pump speed, engine speed with transmission D1+T1 input drive shaft 101. Engage clutch C1 when the difference between the input drive shaft speed and the water pump speed is less than the set value.

[0131] The engine and transmission D1+T1 transmit power to the water pump via the coupling box for water pump fire fighting operations.

[0132] After the operation is completed, disengage clutch C1;

[0133] It enables firefighting operations during operation, allows for smooth mode switching, eliminates shocks, protects the transmission system, and improves reliability.

[0134] As attached Figure 4 As shown, in this embodiment, the specific steps for switching from dual-engine drive mode to driving water-spraying mode are as follows:

[0135] Step S1: In dual-engine drive mode, pressure port ① supplies air, while pressure ports ②, ③, and ④ do not supply air. At this time, clutch C1 is disengaged, and clutches C2 and C3 are engaged. Switches K1 and K3 output signals, while switches K2 and K4 do not output signals. The motor of the engine driving the transmission D1+T1 input drive shaft 101 is engaged with the coupling box 6 via clutch C2, and the motor of the engine driving the transmission D2+T2 input drive shaft 102 is engaged with the coupling box 6 via clutch C2. The power of both is combined through the coupling box 6 and then output to the output front drive shaft 301 and the output rear drive shaft 302 through the internal transmission mechanism of the coupling box 6, driving the vehicle. Step S2 is then executed.

[0136] Step S2: Request to switch the vehicle's water dispensing mode, then proceed to step S3;

[0137] Step S3: Determine whether the vehicle speed is less than the set value (in this embodiment, the set value is set to 40km / h, but it is not limited to this and can be set according to actual needs). If yes, proceed to step S4; if no, proceed to step S6.

[0138] Step S4: Shift transmission T1 back to neutral and proceed to step S5;

[0139] Step S5: Pressure ports ①, ③, and ④ are not supplied with air, while pressure port ② is supplied with air. Disengage clutch C2. At this time, clutch C1 is in the disengaged state, and clutch C3 is in the engaged state. Switch K2 outputs a signal, while switch K3 does not output a signal. At this time, switch K1 is still in the output signal state, and switch K4 is still in the no-output signal state. Proceed to step S7.

[0140] Step S6: Reduce vehicle speed and return to step S3;

[0141] Step S7: Determine whether K2 outputs a signal and K3 does not output a signal. If yes, proceed to step S8; otherwise, proceed to step S9.

[0142] Step S8: Release the PTO drive (the PTO drive shaft 2 connected to the water pump is set in the coupling box, release the brake acting on the PTO drive shaft 2, so that the drive shaft and the water pump impeller shaft connected to it can rotate freely), and execute step S12.

[0143] Step S9: Determine whether the waiting time is greater than the set value (in this embodiment, the set value is 1 second, but it is not limited to this and can be set as needed). If yes, proceed to step S10; otherwise, return to step S7.

[0144] Step S10: Pressure port ① supplies air, pressure port ② does not supply air, re-engage clutch C2. At this time, clutch C1 is still disengaged and clutch C3 is engaged, thus switching to dual-engine drive mode and executing step S11.

[0145] Step S11: An error code is returned, indicating that clutch C2 cannot be disengaged;

[0146] Step S12: Determine whether the speed difference between the two ends of clutch C1 is less than or equal to the set value (in this embodiment, the set value is set to 100 rpm, but it is not limited to this and can be set as needed). If yes, proceed to step S13; otherwise, proceed to step S14.

[0147] Step S13: Pressure ports ② and ③ supply air, pressure ports ① and ④ do not supply air, engage clutch C1, C2 is in the disengaged state, C3 is in the engaged state, K1 does not output a signal, switch K2 is still in the output signal state, and switches K3 and K4 are still in the no-output signal state. Execute step S15.

[0148] Step S14: Adjust the speed difference and return to step S12;

[0149] Step S15: Determine whether K1 is not outputting a signal and whether the clutch C1 pressure is at the set value (in this embodiment, the set value is 6-10 bar, but it is not limited to this and can be set as needed). If yes, proceed to step S16; if no, proceed to step S18.

[0150] Step S16: Engage drive gear in transmission T1 and proceed to step S17;

[0151] Step S17: When the vehicle is in motion, the PTO drive shaft 2 rotates, so that the power from the engine with transmission D1+T1 is transmitted to the PTO drive shaft 2 via the input drive shaft 101 and clutch C1, which drives the water pump. The power from the engine with transmission D2+T2 is transmitted to the output front drive shaft 301 and output rear drive shaft 302 via the transmission mechanism of the coupling box after passing through the input drive shaft 102 and clutch C3, which drives the wheels.

[0152] Step S18: Determine whether the waiting time is greater than the set value (in this embodiment, the set value is 1 second, but it is not limited to this and can be set as needed). If yes, proceed to step S19; otherwise, return to step S15.

[0153] Step S19: Pressure ports ①, ③, and ④ are not supplied with air, while pressure port ② is supplied with air. Disengage clutch C1. At this time, clutch C2 is still disengaged, clutch C3 is engaged, switch K1 outputs a signal, switch K2 is still outputting a signal, and switches K3 and K4 are still not outputting a signal. Proceed to step S20.

[0154] Step S20: An error code is returned, indicating that the water pump cannot be driven.

[0155] In this embodiment, when switching from the driving water-spraying mode to the dual-engine drive mode, first disengage the clutch C1, and synchronize the speeds of both ends of the clutch C2 (the transmission shaft 101 of the engine with the input drive shaft of the transmission D1+T1 gearbox and the transmission mechanism inside the coupling box connected to the clutch C2). When the speed difference between the two ends of the clutch C2 is less than the set value, the clutch C2 is engaged.

[0156] The power from the engine with transmission D1+T1 and the engine with transmission D2+T2 is combined through the coupling box to drive the vehicle together.

[0157] It achieves smooth mode switching, eliminates engagement shock, protects the transmission system, and improves reliability.

[0158] As attached Figure 6 As shown, the specific steps to switch from driving water-spraying mode to dual-engine drive mode are as follows:

[0159] Step S1: In the water pumping mode, pressure ports ① and ④ do not supply air, while pressure ports ② and ③ supply air. At this time, clutches C1 and C3 are engaged, clutch C2 is disengaged, switches K1, K3, and K4 do not output signals, and switch K2 outputs a signal. Then, proceed to step S2.

[0160] Step S2: Request to switch to dual-engine drive mode, then proceed to step S3;

[0161] Step S3: Pressure ports ①, ③, and ④ are not supplied with air, while pressure port ② is supplied with air. Disengage clutch C1. At this time, clutch C2 is in the disengaged state, clutch C3 is in the engaged state, switch K1 outputs a signal, switch K2 is still in the output signal state, and switches K3 and K4 are still in the no-output signal state. Proceed to step S4.

[0162] Step S4: Determine whether K1 outputs a signal and the clutch C1 pressure is ≤ set value (in this embodiment, the set value is 0.2 bar, but it is not limited to this and can be set as needed). If yes, proceed to step S5; if no, proceed to step S7.

[0163] Step S5: Brake PTO drive shaft 2, proceed to step S6;

[0164] Step S6: Adjust the rotational speed at both ends of the synchronous coupling box clutch C2, and proceed to step S9;

[0165] Step S7: Determine whether the waiting time is greater than the set value (in this embodiment, the set value is 1 second, but it is not limited to this and can be set as needed). If yes, proceed to step S8; otherwise, return to step S4.

[0166] Step S8: An error code is returned, indicating that clutch C1 cannot be disengaged;

[0167] Step S9: Determine whether the speed difference between the two ends of clutch C2 is less than or equal to the set value (in this embodiment, the set value is 30±20 rpm, but it is not limited to this and can be set as needed). If yes, proceed to step S10; otherwise, proceed to step S11.

[0168] Step S10: Pressure port ① supplies air, pressure ports ②, ③, and ④ do not supply air, engage clutch C2. At this time, clutch C1 is disengaged, clutch C3 is engaged, switch K2 does not output a signal, switch K3 outputs a signal, switch K1 is still outputting a signal, and switch K4 is still not outputting a signal. Proceed to step S12.

[0169] Step S11: Adjust the speed difference and return to step S9;

[0170] Step S12: Determine whether switch K3 outputs a signal and switch K2 does not output a signal. If yes, proceed to step S13; otherwise, proceed to step S14.

[0171] Step S13: The power from the engine with transmission D1+T1 and the engine with transmission D2+T2 is combined through the coupling box to drive the wheels;

[0172] Step S14: Determine whether the waiting time is greater than the set value (in this embodiment, the set value is 1 second, but it is not limited to this and can be set as needed). If yes, proceed to step S15; otherwise, return to step S12.

[0173] Step S15: Pressure ports ①, ③, and ④ are not supplied with air, while pressure port ② is supplied with air. Disengage clutch C2. At this time, clutch C1 is in the disengaged state, and clutch C3 is in the engaged state. Switch K2 outputs a signal, while switch K3 does not output a signal. At this time, switch K1 is still in the output signal state, and switch K4 is still in the no-output signal state. Proceed to step S16.

[0174] Step S16: Returns error code, cannot combine engine with transmission D1+T1.

[0175] When it is necessary to fill the water pump while the vehicle is parked, pressure port ① is not supplied with air, while pressure ports ② and ③ are supplied with air. Clutch C1 is engaged, and clutches C2 and C3 are disengaged. The engine, along with transmission D1+T1, transmits power to the water pump through the coupling box to perform the water pumping operation while the vehicle is parked. At this time, engine D2 is either idling or off.

[0176] In this embodiment, the internal transmission mechanism of the coupling box includes meshing gear sets, gear shafts, etc. Those skilled in the art will understand that the specific configuration of the gears and gear shafts can be changed and arranged in various ways depending on the position of the input and output shafts.

[0177] Through the mode switching of this application, the fire truck can select the appropriate working mode according to the specific working conditions. In particular, it can smoothly combine the water pump to carry out fire fighting operations during the driving process, and smoothly cut off the water pump power and switch to single or dual-engine drive driving mode after the fire fighting operation is completed. This meets the usage requirements of fire trucks as emergency products, and can improve the comfort and stability of the whole vehicle and enhance the vehicle's NVH performance.

[0178] Example 2:

[0179] The difference between Example 2 and Example 1 is that when the driving water pumping mode and the parking water pumping mode are selected, the engine drives the transmission D2+T2 in conjunction with the water pump.

[0180] In this embodiment, clutch C1 is used to control the engagement or disengagement of the engine-driven transmission D2+T2 with the coupling box to switch the power to the water pump; clutch C2 is used to control the engagement or disengagement of the engine-driven transmission D2+T2 with the coupling box to switch the power to the vehicle drive shaft; clutch C3 is used to control the engagement or disengagement of the engine-driven transmission D1+T1 with the coupling box to switch the power to the vehicle drive shaft.

[0181] In the driving water pumping mode, by disengaging clutch C2 and engaging clutch C1, the power from the engine driving transmission D2+T2 is transmitted to the water pump via the coupling box. By engaging clutch C3, the power from the engine driving transmission D1+T1 is transmitted to the vehicle drive shaft via the coupling box.

[0182] In the parking water pumping mode, by disengaging clutches C2 and C3, the power from the engine driving transmission D2+T2 and the engine driving transmission D1+T1 will not be transmitted to the vehicle drive shaft through the coupling box. By engaging clutch C1, the power from the engine driving transmission D2+T2 will be transmitted to the water pump through the coupling box, thus enabling parking fire fighting operations.

Claims

1. A mode selection control system for a coupling box used in fire trucks, characterized in that: The vehicle's operating modes include dual-engine drive mode, single-engine drive mode, driving water dispensing mode, and parking water dispensing mode. When the dual-engine drive mode is selected, the two power sources, engine with transmission D1+T1 and engine with transmission D2+T2, are combined through the coupling box to drive the vehicle together. When the single-engine drive mode is selected, the power from the engine with transmission D1+T1 or the engine with transmission D2+T2 drives the vehicle through the coupling box, while the other engine is idling or off. When the vehicle is selected to operate in water-spraying mode, the power from either the engine with transmission D1+T1 or the engine with transmission D2+T2 drives the vehicle through the coupling box, while the power from the other engine with transmission D1+T1 or the engine with transmission D2+T2 is output to the water pump for firefighting operations through the coupling box. When the vehicle is in parking water pumping mode, the power of one of the two engines, D1+T1 and D2+T2, is output to the water pump via the coupling box for fire fighting, while the other engine is in idling or off state. The coupling box is equipped with clutches C1, C2 and C3; The clutch C1 is used to control the engagement or disengagement of one of the engine-driven transmission D1+T1 and the engine-driven transmission D2+T2 with the coupling box to switch the power to the water pump on or off. The clutch C2 is used to control the engagement or disengagement of one of the engine-driven transmissions D1+T1 and D2+T2 with the coupling box to switch power to the vehicle drive shaft. The clutch C3 is used to control the engagement or disengagement of one of the engine-driven transmissions D1+T1 and D2+T2 with the coupling box to switch power to the vehicle drive shaft. To switch from dual-engine drive mode to driving water mode, first reduce the vehicle speed, disengage clutch C2, and disconnect one of the engine-driven transmission D1+T1 and engine-driven transmission D2+T2 from the coupling box. The system detects vehicle speed, water pump speed, and the speed of one of the input drive shafts, namely engine with transmission D1+T1 and engine with transmission D2+T2. When the difference between the input drive shaft speed and the water pump speed is less than the set value, clutch C1 is engaged. The engine and transmission D1+T1 and the engine with transmission D2+T2, one of which transmits power to the water pump via the coupling box for water pump fire fighting operations; After the operation is completed, disengage clutch C1; To switch from driving water-spraying mode to dual-engine drive mode, first disengage clutch C1, synchronize the speeds of both ends of clutch C2, and when the speed difference between the two ends of clutch C2 is less than the set value, engage clutch C2. The power from the engine with transmission D1+T1 and the engine with transmission D2+T2 is combined through the coupling box to drive the vehicle together.

2. The mode selection control system for a coupling box for a fire truck according to claim 1, characterized in that: The vehicle operating modes also include neutral and traction modes. When the vehicle needs to be towed, select neutral and traction modes. Both the engine with transmission D1+T1 and the engine with transmission D2+T2 are disconnected from the coupling box, and transmissions T1 and T2 are put back into neutral.

3. A mode selection control system for a coupling box for a fire truck according to claim 1 or 2, characterized in that: The coupling box is provided with four pressure ports, including pressure port 1, pressure port 2, pressure port 3 and pressure port 4; The pressure port 1 and pressure port 2 work together to control the engagement and disengagement of clutch C2; The pressure port 3 controls the engagement and disengagement of the clutch C1; The pressure port 4 controls the engagement and disengagement of the clutch C3.

4. The mode selection control system for a coupling box for a fire truck according to claim 3, characterized in that: When pressure port 1 supplies air and pressure port 2 does not supply air, clutch C2 is engaged; when pressure port 1 does not supply air and pressure port 2 supplies air, clutch C2 is disengaged; or, when pressure port 1 supplies air and pressure port 2 does not supply air, clutch C2 is disengaged; when pressure port 1 does not supply air and pressure port 2 supplies air, clutch C2 is engaged. When pressure port 3 supplies air, clutch C1 engages; when pressure port 3 does not supply air, clutch C1 disengages. Alternatively, when pressure port 3 supplies air, clutch C1 disengages; when pressure port 3 does not supply air, clutch C1 engages. When pressure port 4 supplies air, clutch C3 engages; when pressure port 4 does not supply air, clutch C3 disengages. Alternatively, when pressure port 4 supplies air, clutch C3 disengages; when pressure port 4 does not supply air, clutch C3 engages.

5. A mode selection control system for a coupling box for a fire truck according to claim 1, 2, or 4, characterized in that: Clutches C1 and C2 are normally open clutches, and clutch C3 is normally closed clutch.

6. A mode selection control system for a coupling box for a fire truck according to claim 1, 2, or 4, characterized in that: The coupling box is equipped with four detection switches for feedback on the clutch engagement or disengagement status. The switches include switch K1, switch K2, switch K3 and switch K4. The switch K1 provides feedback on the engagement or disengagement status of the clutch C1; The switch K2 and switch K3 are in the state of feedback clutch C2 being engaged or disengaged; The switch K4 provides feedback on the engagement or disengagement of the clutch C3.

7. A mode selection control system for a coupling box for a fire truck according to claim 6, characterized in that: When clutch C1 is engaged, switch K1 outputs a first signal; when clutch C1 is disengaged, switch K1 outputs a second signal or no signal. Alternatively, when clutch C1 is disengaged, switch K1 outputs a first signal; when clutch C1 is engaged, switch K1 outputs a second signal or no signal. When clutch C2 is engaged, switch K2 outputs the first signal, and switch K3 outputs the second signal or no signal. When clutch C2 is disengaged, switch K2 outputs the second signal or no signal, and switch K3 outputs the first signal; or, when clutch C2 is disengaged, switch K2 outputs the first signal, and switch K3 outputs the second signal or no signal; when clutch C2 is engaged, switch K2 outputs the second signal or no signal, and switch K3 outputs the first signal. When clutch C3 is engaged, switch K4 outputs a first signal; when clutch C3 is disengaged, switch K4 outputs a second signal or no signal. Alternatively, when clutch C3 is disengaged, switch K4 outputs a first signal; when clutch C3 is engaged, switch K4 outputs a second signal or no signal.

8. A mode selection control system for a coupling box for a fire truck according to claim 1, 2, 4, or 7, characterized in that: During the dual-engine drive mode, the output power and speed of the two engines are adjusted synchronously according to the vehicle accelerator pedal opening value and vehicle speed to maintain their consistent operating status. The vehicle's gear shifter controls the two transmissions to switch gears synchronously, ensuring that the two transmissions are in the same gear and that the switching time is consistent.

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