Claims:We Claim:

1. A system (100) for reducing individual accessory load for an engine of a vehicle, comprising:
a speed regulating device (102) configured to regulate the individual accessory speed based on operating conditions of the engine, wherein said speed regulating device (102) comprises a first component (104) attached to each of the accessories and having a clutch bell and crankshaft pulley integrated;
and a second component (106) attached to the engine and having a clutch attached to the crankshaft, wherein the second component uses a solenoid (108) to control the speed of the accessories based on the requirement coming from the engine on to the accessories.

2. The system (100) as claimed in claim 1, wherein said solenoid (108) is controlled by an electronic control unit (ECU) (110).

3. The system (100) as claimed in claim 2, the electronic control unit (110) configured to set reference maps, where the individual accessory load requirement is mapped to the speed of the pulley, the speed of the pulley is in turn mapped to the amount of current required by the solenoid (108).

4. The system (100) as claimed in claim 2, the electronic control unit (110) is configured to actuate the solenoid (108) based on calculated current required to maintain the required speed, which in turn partially disconnects the accessory which is not in use, from the engine drive pulley.

5. The system (100) as claimed in claim 1, wherein degree of contact of said first component (104) and second component (106), ensure the amount of energy transferred to each of the individual accessory of the vehicle.

6. The system (100) as claimed in claim 1, said speed regulating device (102) is further configured to act like a clutch which is always set to transfer the minimum load and based on the current which is supplied to said solenoid (108), the load transfer increases.

7. The system (100) as claimed in claim 1, accessories of the engine includes but not limited to air pump, air conditioning compressor, vehicle alternator, power steering pump, water pump or the like.

8. A method (200) for reducing individual accessory load for an engine, the method comprising:
calculating (201) the individual accessory load based on the engine speed;
comparing (202) the calculated accessory load with a certain minimum accessory load;
setting (203) minimum solenoid (104) current to operate the accessory on minimum load, if the calculated accessory load is lesser than the certain minimum accessory load; or
controlling (204) the load on accessories by varying the current to the solenoid (104), if the calculated accessory load is greater than the certain minimum accessory load.
, Description: Complete Specification:

The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed.

Field of the invention
[0001] Present invention relates generally to system and method for reducing fuel consumption and CO2 emission by reducing accessory load on an engine of a vehicle. The invention relates in specific to a system and method to reduce the load on the engine from FEAD (Front Engine Accessories Drive) in a vehicle.

Background of the invention
[0002] In vehicles, front-end accessory drives (FEAD) are used to power vehicle accessories. These accessories may include a power steering pump, a water pump, an alternator, an air conditioning compressor, an air compressor, a power-take off (PTO) drive, etc. These components are driven by a front end accessory drive (FEAD) or belt drive system. The FEAD is, thus, coupled to multiple dynamic loads that each exerts generally different forces and torques during their operation on engine. As known in the industry, the accessories driven by the FEAD consume power that could otherwise be directed to propulsion of the vehicle, thereby affecting fuel consumption. The greater the number of front end accessories, the more complex the dynamics of the system. The dynamics are functions of parameters such as pulley diameter, inertia, load caused by transfer of energy, and engine speed.

[0003] Existing solutions for the above-mentioned problems includes concepts which proposes to disconnect the accessories completely during start and acceleration to reduce the load on the engine but it becomes no more relevant as all the vehicles primarily uses power steering which is driven by the engine accessory drive, disconnecting that in the vehicle drive conditions would prove fatal.

[0004] The prior art US9221451B2 discloses an electronic control unit (“ECU”) and/or accessory control module configured to improve actual fuel, economy. The ECU and/or the accessory control module monitors vehicle operating conditions and reduces load from an accessory when the vehicle achieves predetermined operating conditions. The ECU and/or the accessory control module is also configured to engage a fuel cut and a torque converter lock up condition. The lock up condition causes the wheels to drive the motor to avoid engine stall. At a predetermined low level, the ECU and/or the accessory control module can re-engage the accessory and fuel supply and disengage the lock up condition.

[0005] Another prior art US4688530A discloses a control system for an accessory of an automobile includes an engine output detector for detecting the output of the engine of the automobile, a gear transmission coupled to the engine and responsive to detection of an idling condition of the automobile for selecting a neutral gear position, an accessory such as an air conditioner compressor drivable by the engine, a clutch disposed between the accessory and the engine for applying and cutting off the output of the engine to the accessory, a speed sensor for detecting the speed of travel of the automobile, a control circuit for comparing an actual running condition of the automobile with a prescribed running condition in which the output of the engine and the speed of the automobile are lower than respective prescribed levels, and for inhibiting operation of the accessory by disconnecting the clutch when the automobile is under the prescribed running condition.

Brief description of the accompanying drawing
[0006] Different modes of the invention are disclosed in detail in the description and illustrated in the accompanying drawing:

[0007] Fig. 1 illustrates a system for reducing individual accessory load for an engine, of a vehicle according to one embodiment of the invention.

[0008] FIG. 2 is an example process for reducing individual accessory load for an engine, using the system of FIG. 1, according to the aspects of the present technique.

Detailed description of the embodiments
[0009] FIG. 1 illustrates a system 100 for determining individual accessory load for an engine, in a vehicle. A typical vehicle engine includes a crankshaft which mounts a clutch and pulley assembly. A drive belt interconnects the pulley assembly with each of the individual accessories of the engine of a vehicle. Herein, the accessories of the engine, may include, but not limited to, air pump, air conditioning compressor, vehicle alternator, power steering pump, water pump or the like. A slip ring assembly and electrical lead transmit an electrical signal actuating the clutch and pulley assembly. The clutch and pulley assembly includes a driving member which is mounted for rotation with the crankshaft, so that the driving member is rotated by operation of the engine.

[0010] The system 100 includes a speed regulating device 102 configured to regulate the individual accessory speed based on operating conditions of the engine. The speed regulating device 102 further includes a first component 104 and a second component 106. Each component of the system 100 is further described below.

[0011] The first component 104 of the speed regulating device 102, is attached to each of the accessories and having a clutch bell and crankshaft pulley integrated. The crankshaft pulley is mounted on the end of the crankshaft. In one example, the role of the crankshaft pulley is to turn the drive belts that operates the accessories of the engine. The clutch bell is adapted to transmit the torque from the engine to the drive belt. Smoothly deliver the power from the engine to enable smooth vehicle movement.

[0012] The second component 106 of the speed regulating device 102, is attached to the engine and having a clutch attached to the crankshaft. The second component 106 uses a solenoid 108 to control the speed of the accessories based on the requirement coming from the engine on to the accessories. In one embodiment, the solenoid 108 is controlled by an electronic control unit (ECU) 110. The ECU 110 configured to set reference maps, where the individual accessory load requirement is mapped to the speed of the pulley, the speed of the pulley is in turn mapped to the amount of current required by the solenoid 108. Herein, reference map, plots current given to the solenoid 108 based on engine speed and required accessory speed.

[0013] In working, based on the current input to the solenoid 108 and the engine speed, the ECU 110 will monitor the accessory load. In an example, when the air conditioner is not in use or its switch is off, the AC compressor can be made to run at the minimum speed as there is no load on the compressor. In one embodiment, the degree of contact of said first component 104 and second component 106, will ensure the amount of energy transferred to each of the individual accessory of the vehicle. In one example, the speed regulating device 102 is further configured to act like a clutch which is always set to transfer the minimum load and based on the current which is supplied to said solenoid 108 the load transfer increases. The ECU 110 actuates the solenoid 108 based on the calculated current required to maintain the required speed, which in turn partially disconnects the accessory which is not in use, from the engine drive pulley.

[0014] FIG. 2 is an example process 200 for reducing individual accessory load for an engine, using the system of FIG. 1, according to the aspects of the present technique.

[0015] At step 201, the individual accessory load based on the engine speed is calculated. At step 202, the calculated accessory load is compared with a certain minimum accessory load. If the calculated accessory load is lesser than the certain minimum accessory load, then at step 203, minimum solenoid 108 current is set to operate the accessory on minimum load. In another situation, if the calculated accessory load is greater than the certain minimum accessory load, then at step 204, the load on accessories is controlled by varying the current to the solenoid 108. In this embodiment, the ECU 110 actuates the solenoid 108 based on the calculated current required to maintain the required speed, which in turn partially disconnects the accessory which is not in use, from the engine drive pulley. As a result, on disconnecting the accessory which is not in use, the load on the engine can be reduced.

[0016] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.