Claims:1. A start assist system (105) of an engine for a vehicle, the start assist system (105) comprising:
a cable link bridge (205);
a user input throttle cable (201) attached to a first end of the cable link bridge (205);
an carburettor input cable (202) attached to a substantial center portion of the cable link bridge (205);
a start assist cable (203) attached to a second end of the cable link bridge (205); and
a solenoid actuator (204) configured to operate the start assist cable (203).
2. The start assist system (105) as claimed in claim 1, wherein
said user input throttle cable (201) being configured to take a first throttle input from a user operation of the vehicle,
said start assist cable (203) being configured to provide a second throttle input from an electronic control unit (206) based on one or more engine function parameters; and
said carburettor input cable (202) being configured to provide a throttle valve opening input to a carburettor (103) based on one or more of the first throttle input and the second throttle input.

3. The start assist system (105) as claimed in claim 2, wherein the one or more of the first throttle input and the second throttle input being transferred to the cable link bridge (205) and input for the throttle valve being transferred from the cable link bridge (205) to the carburettor input cable (202).
4. The start-assist system (105) as claimed in claim 2, wherein one end of the carburettor input cable (202) being connected to a throttle valve of the carburettor (103).
5. The start-assist system (105) as claimed in claim 2, wherein the one or more engine function parameters comprise of one or more of the engine temperature and engine idling speed.
6. The start-assist system (105) as claimed in claim 1, wherein a first end of the start assist cable (203) being connected to the solenoid actuator (204), and a second end of the start assist cable (203) being connected to the second end of the cable link bridge (205).
7. The start-assist system (105) as claimed in claim 1, wherein the solenoid actuator (204) being configured to take input from the electronic control unit (206).
8. The start assist system (105) as claimed in claim 1, wherein the cable link bridge (205) is fixed as a slider wherein the slider being configured to a base portion of the engine (100) or vehicle.
9. A method of start assist system (105), the method comprising of :
Computing (step 302) real time one or more engine function parameters by an electronic control unit (206);
comparing (step 303) computed real time one or more engine function parameters with a predetermined threshold value of one or more engine function parameters by said electronic control unit (206);
activating (step 304) a solenoid actuator (204) by said electronic control unit (206) in case the value of computed one or more engine function parameter is less than predetermined threshold value of one or more engine function parameters,
transferring motion (step 305) of the solenoid actuator (204) to the cable link bridge (205) by start assist cable (203);
transferring motion (step 306) of the cable link bridge (205) to an input cable (202);
opening throttle valve (step 307) of a carburettor (103) by the motion of the input cable (202);
or
deactivating (step 308) the solenoid actuator (204) by said electronic control unit (206) in case the value of computed real time one or more engine function parameter is more than or equal to predetermined threshold value of one or more engine function parameters.
10. The method as claimed in claim 9, wherein the first throttle input and the second throttle input both are active, net displacement of the carburettor input cable (202) will be the maximum of first throttle input and second throttle input. , Description:TECHNICAL FIELD
[0001] The present subject matter relates generally to a start assist system of a vehicle. More particularly but not exclusively the present subject matter relates to controlling fuel flow to the carburettor as per engine requirements.
BACKGROUND
[0002] In conventional fuel regulator system for an internal combustion engine, a carburettor is used to regulate air oil mixture in the engine. Traditional carburettor systems have been replaced by Electronic Fuel Injection (EFI) systems which provide a very refined and precise control of the performance characteristics of the supply of air-fuel mixture. However, EFI systems necessitate incorporation of controller and sensors etc. which adversely increase the cost of the system as well as the vehicle. Electronic Throttle Control (ETC) is often integrated with EFI system to further enhance the performance as well as comfort albeit at a cost impact. Conventional carburettor-based control systems depend on opening and closing of one or more throttle orifice typically actuated through a throttle input from the user which can be in form of a throttle cable or an accelerator pedal cable. Given the wide range of non-linear operation and usage of the vehicle in terms engine speed, vehicle load, etc. it often is a challenge of optimisation and calibration of the carburettor system to the best possible setting which may not necessarily be the best setting for a given operating condition.

BRIEF DESCRIPTION OF THE DRAWINGS
[0003] The same numbers are used throughout the drawings to refer similar features and components.
[0004] Figure 1 exemplarily illustrates a general arrangement of start assist system in a vehicle in accordance with one or more implementation.
[0005] Figure 2 exemplarily illustrates a start assist system in accordance with one or more implementation.
[0006] Figure 3 exemplarily flow chart of the working of the start assist system in accordance with one or more implementation.
[0007] Figure 4 (a) exemplarily illustrates neutral view of the start assist system in accordance with one or more implementation.
[0008] Figure 4 (b) exemplarily illustrates first throttle input in start assist system in accordance with one or more implementation.
[0009] Figure 4 (c) exemplarily illustrates second throttle input in start assist system in accordance with one or more implementation.
DETAILED DESCRIPTION
[00010] Adequate throttle opening of the carburettor is required in order to crank the engine. In general, during low atmospheric temperature the oil becomes viscous. The viscous oil has more friction, which as a result applies too much friction around the components that needs to move at high speed for cranking the engine. Thus, it is evident that in order to crank the engine at lower temperature, there is a need to provide more amount of oil and air mixture to the engine for adequate lubrication of the internal components. Therefore, to compensate the viscosity impact, the user of the vehicle ends up increasing the throttle opening through handle bar grip thereby supplying additional air and oil to the engine.
[00011] In addition, in lower temperatures idling speed of the engine is low that leads to poor idling stability. However, if the engine idling speed in cold situation is adjusted with the carburettor throttle opening, then the engine idling speed in the normal start condition increases to more than required value which leads to poor idling and undesirably high fuel consumption. In addition, excessive use of force by the user for throttle opening makes the user exhausted. Hence, it is difficult to have a carburettor type throttle control without compromises. Thus, there is requirement of a system that assist the engine to start,. Cranking engine in lower atmospheric temperature or in cold start conditions is difficult. Therefore, it is important that sufficient amount of air fuel mixture is supplied to the engine which is often in form of a rich mixture during cold start conditions. In the present state of art when the user switches on the ignition key, there could be two situations- in first situation engine is started without throttle opening by the driver, wherein due to insufficient air flow the engine may/may not start. Secondly, if the engine has started, engine may switch OFF due to low engine speed leading to stalling of engine in the idling condition. While in the second situation, the engine is started due to throttle opening by the user, though with excess airflow, the engine may start and run at higher idling speed. However, if the user leaves the throttle, the engine may get switched off or the user will have to hold the throttle to maintain the idling speed. Throttle opening by user is a common way of supplying adequate amount of air fuel mixture. However, such method of supplying air fuel mixture by the user has its own limitations such as increasing idling speed, reducing fuel efficiency, exhaustion of user, excess emissions etc. Therefore, with such a system it is difficult to start and operate the vehicle with stable idling, without user giving throttle assistance when engine is cold or subject with sudden electrical load requirements. Hence, to overcome the above prior art problems, the present invention discloses an automated start assist system for a vehicle.
[00012] An existing prior art suggests that a temperature sensor is attached separately on the vehicle aggregate e.g., a motor, to detect temperature, but such a system uses an additional sensor, which adds cost of manufacturing of the vehicle.
[00013] An objective of the present is invention is to provide an automatic start assist system for a vehicle. The present invention provides a system which can start assist the engine cranking based upon start condition of the vehicle such as low temperature. The present invention is applicable to vehicle having an engine. The start assist system primarily includes a cable link bridge, a user input throttle cable, a carburettor input cable, a start assist cable, and a solenoid actuator The cable link bridge have a first outer end and a second outer end in longitudinal direction. The solenoid actuator is located at one end of the cable link bridge width direction. As per an aspect of the present invention, the user input throttle cable and the start assist cable is connected to the first outer end of the cable link bridge and the second outer end of the cable link bridge respectively. One end of the user input throttle cable and one end of the start assist cable are connected to the cable link bridge by a stopper in the direction of the solenoid actuator. The start assist cable is connected to the solenoid actuator at the other end. One end of the carburettor input cable is connected on the centre portion of the cable link bridge in opposite direction of the user input throttle cable and start assist cable by the stopper. More specifically, the carburettor input cable is connected at the opposite direction of the solenoid actuator.
[00014] As per an aspect of the present invention, all the cables have their individual functions. The user input throttle cable takes input from the user for the opening of throttle from the other end. The solenoid actuator connected to the start assist enables the start assist cable to send throttle input to the carburettor based on inputs from an electronic control unit to the solenoid actuator. The electronic control unit sends input to the solenoid actuator based upon predetermined engine function parameters. The carburettor input cable provides the throttle valve opening to the carburettor based upon the first throttle input received from the user input throttle cable and the second throttle input received from start assist cable.
[00015] As per an aspect of the present invention, the first throttle input by the user input throttle cable and the second throttle input by the start assist cable is transferred to the carburettor input cable via the cable link bridge.
[00016] As per an aspect of the present invention, one end of the carburettor input cable is connected to the cable link bridge while the other end is connected to the slider/ throttle of the carburettor. Such a configuration enables the transfer of motion of cable Link Bridge to the carburettor slides via the input cable.
[00017] As per an aspect of the present invention, the engine function parameters can be one or more of an engine temperature, engine RPM etc. More specifically, the engine function parameters involves the engine operating conditions and circumstances.
[00018] As per an aspect of the present invention, the start assist cable is connected to the solenoid actuator at one end while the other end is connected to the cable link bridge.
[00019] As per an aspect of the present invention, the solenoid actuator is configured to receive input from the electronic control unit (ECU). The input from the ECU is thus transferred to start assist cable.
[00020] As per an aspect of the present invention, the cable link bridge is connected as slider on a vehicle member.
[00021] As per an embodiment of the present invention, the methodical steps of working of the start assist system begin with the ECU computing the engine function parameters in a real time basis. Subsequently, the ECU compares the computed values with a predetermined set of threshold values. In case the computed values of engine function parameters is less than that of threshold values of parameters, the ECU activates the solenoid actuator by bringing the solenoid actuator into motion. The motion of the solenoid actuator is transferred to the cable link bridge via start assist cable which connect the solenoid actuator at one end. The motion of the cable link bridge is further transferred to the carburettor input cable. As a result, the carburettor input cable opens the throttle valve of the carburettor. On the other hand, in case the computed values by the ECU is more than that of predetermined set of threshold values, the ECU deactivates the solenoid actuator, and thus the second throttle input becomes zero.
[00022] As per yet another aspect of the present invention, in case the first throttle input and second throttle input both are applied at a same time, the input to the input cable will be the maximum among the first throttle input and the second throttle input.
[00023] The present invention provides a system, which is capable of providing required throttle input to the carburettor in case the engine is not able to crank due to lower temperature or any other factor which leads to insufficient air oil mixture in the engine. In addition, the present invention is simple, and does not require changes in the existing carburettor design, hence the present system is universal in application. Additionally, the present invention reduces the application of force on the throttle input thereby eliminating any physical exhaustion of the user. The present invention is fully automatic with real time calculation of parameters, thus reliable in everyday usage.
[00024] The present subject matter is further described with reference to accompanying figures. It should be noted that the description and figures merely illustrate principles of the present subject matter. Various arrangements may be devised that, although not explicitly described or shown herein, encompass the principles of the present subject matter. Moreover, all statements herein reciting principles, aspects, and examples of the present subject matter, as well as specific examples thereof, are intended to encompass equivalents thereof.
[00025] Fig.1 exemplarily illustrates a typical arrangement of start assist system (105) in an engine assembly. A carburettor (103) mixes air and fuel for the engine in desired air fuel ratio for engine cranking. The air fuel ratio is supplied to the engine (100) by engine intake pipe (102) for cranking of engine (100). A throttle valve (not shown) controls the amount of air and fuel mixture released into the engine (100). The throttle valve (not shown) is connected to the start assist system (105) for automatic controlled opening of said throttle valve (not shown) of the carburettor (103). During cold start conditions or in circumstances where the throttle valve opening is not sufficient for the engine cranking, the user provides throttle for increasing the idling speed of the engine (100). However, as explained earlier, user-controlled throttle opening is not always sufficient to crank the engine. Additionally it increases the engine idling speed in normal or hot start conditions, which is not a fuel-efficient operation. Subsequent to user input of throttle, the vehicle may stop again once the user stops providing throttle input. In addition, user tends to get exhausted by applying extra force to open the throttle valve (not shown). The start assist system (105) assists in throttle opening for easy cranking of the vehicle based upon various engine operating parameters such as temperature, engine RPM etc. Said start assist system (105) is implemented by making changes in the carburettor cable system alone and does not require any change in the carburettor (103) design, thus the present invention is universal in application for all kinds of vehicle.
[00026] Fig.2 exemplarily illustrates the start assist system (105). The start assist system primarily includes a solenoid actuator (204), an electronic control unit (ECU) (206) connected to said solenoid actuator (204) to actuate the actuator, three set of cables: user input side throttle cable (201), a start assist cable (203) and an carburettor input throttle cable (202), and a cable link bridge (205) which links at least one end of each cables (201,202,203). First end of the user input throttle cable (201) is attached to a first end of the cable link bridge (205) while the second end is connected to the handle bar throttle or pedal actuator such that actuation of the user input throttle cable (201) exerts pull force on the first end of the cable link bridge (205) wherein the movement of the cable link bridge (205) is configured to be in the direction towards the pull movement of the user input throttle cable (201). First end of the carburettor input cable (202) is attached to a mid-portion of the cable link bridge (205) while the second end is coupled to a throttle valve of the carburettor and configured on the opposite side of the disposition of the throttle cable such that movement of the cable link bridge (205) towards the pull direction of the user input throttle cable (201) results in pull of the carburettor input cable (202) in the same direction, which in turn actuates the throttle valve by a magnitude corresponding to the magnitude of movement of the cable link bridge (205). A first end of the start assist cable (203) is connected to the cable link bridge (205) at a second end of the cable link bridge (205) and is configured such that the start assist cable (203) is disposed on the same side as that of the user input throttle cable (201) with respect to the cable link bridge (205). As per an embodiment, the cable link bridge (205) is a plate with three holes. The user input throttle cable (201) and the start assist cable (203) are inserted into the cable link bridge (205) from one side and fixed on the other side with a fastening mechanism (shown schematically, not labelled)). Similarly, the carburettor input cable (202) is inserted into the cable link bridge (205) from the opposite direction and fixed on the cable link bridge (205) with a fastening mechanism (shown schematically, not labelled)). The cable link bridge (205) is configured to be coupled with a base portion (not shown) of the engine or vehicle such that cable link bridge (205) can slide with respect to the base portion. The second end of the start assist cable (203) is connected to the solenoid actuator (204), the second end of the carburettor input cable (202) is coupled to the throttle valve (not shown) of the carburettor (103) and the second end of the user input throttle cable (201) is connected to a handle bar or driver input points, which transmits driver input. As per another embodiment, the three cables are made up of metals, which are reinforce together, and are supported by a cable outer element fixed to the vehicle.
[00027] Fig.3 illustrates a flowchart of working of the start assist system. When the user starts the vehicle at step 301, at step 302, the ECU (206) computes the engine working parameters. More specifically, the ECU (206) computes the value of significant parameters in which the engine (100) is operating such as temperature, RPM etc. After computing the value of the engine working parameters (step 302), at step 303 the ECU determines if one or more of the computed engine working parameter is less or more than a predetermined threshold value of engine working parameter (step 303). In case, the one or more computed engine working parameter is less than the predetermined threshold value of engine working parameter , then at step 304 ECU (206) activates the solenoid actuator (204) due to which solenoid actuator (204) is retracted and moves in direction away from the cable link bridge (205). Then at step 305, retraction of the solenoid actuator (204) is transferred to the cable link bridge (205) via start assist cable (203) due to which cable link bridge (205) is retracted or slid away from the carburettor thereby resulting in pull force being exerted on the carburettor input cable (202) at step 306 as a result of the cable link bridge (205) being pulled towards solenoid actuator direction. Further at step (207), the motion of carburettor input cable (202) creates a linear or angular motion in the throttle valve (not shown) of the carburettor (103). The solenoid actuator (204) and the throttle valve (not shown) remain in the above position till the one or more computed engine working parameter is less than the predetermined threshold value of one or more engine working parameter . When the one or more computed engine working parameter is more than the predetermined threshold value of the one or more engine working parameter at step 308, the ECU (206) deactivates the solenoid actuator and the start assist cable (203) no longer assists the motion of the throttle valve (not shown). The start assist system (105) works during vehicle motion as well as during the start of the vehicle. In case at step 203, the ECU determines if one or more of the computed engine working parameter is equal or more than a predetermined threshold value of engine working parameter, then the ECU (206) does not actuate the solenoid actuator and remains in deactivated state as in step 308.
[00028] Fig. 4(a) schematically illustrates neutral position of the start assist system (105). In the neutral position, all the three cables (201,202,203) are at their neutral position with no assist over the actuation of the throttle valve (not shown).
[00029] Fig. 4(b) schematically illustrates first throttle input in the vehicle. The user input throttle cable (201) provides first throttle input from the user. The throttle cable (201) is fixed in a way that it cannot influence the solenoid actuator (204). Even when the solenoid actuator is retracted, the motion of the user input throttle cable is not hindered. When the user provides the first throttle input through user input throttle cable (201), the cable link bridge (205 ) is retracted which further transfers the motion to the carburettor input cable (202) and the throttle valve (not shown) is moved or assisted in its movement. During this time, the start assist cable (203) remains in neutral or unactuated position.
[00030] Fig. 4 (c) schematically illustrates second throttle input. The second throttle input is provided by the solenoid actuator (204) controlled by ECU (206) and the force is exerted via start assist cable (203). The maximum displacement of start assist cable (203) is configured to be less than maximum permissible displacement of carburettor input cable (202). As a result, when start assist cable (203) provides assisting actuation displacement to the cable link bridge (205), the displacement input from the user input throttle cable (201) is not disturbed or compromised because of the construction of the present invention. The travel of the start assist cable (203) is limited by the solenoid actuator (204). However, in case both the first throttle input by the user input throttle cable (201) and the second throttle input by the start assist cable (203) is active, then the net displacement of the carburettor input cable (202) is configured to be the maximum displacement among the displacement of the user input throttle cable (201) and the start assist cable (203).
[00031] E.g. If the displacement of the user input throttle cable (201) is X units, and if the displacement of the start assist cable (203) is X + delta units, then the net displacement of the carburettor input cable (202) shall be X + delta units. In this scenario, the start assist cable (203) augments the throttle functioning by magnitude equivalent to delta units. Alternatively, if the displacement of the start assist cable (203) is X units, and if the displacement of the user input throttle cable (201) is X + delta units, then the net displacement of the carburettor input cable (202) shall be X + delta units implying the user input over rides the start assist input by delta units which is particularly effective in enabling user to provide additional input during cold start conditions.
[00032] By assisting in opening more throttle valve during cold condition based upon predetermined engine function parameters , the current invention aids the vehicle in achieving optimised idling speed control and avoids vehicle switching off. Therefore, fuel wastage is avoided and leading to better mileage and performance.
[00033] Many other improvements and modifications may be incorporated herein without deviating from the scope of the invention.

List of Reference numerals
100: Engine
101: Piston
102: Engine intake pipe
103: Carburettor
105: Start assist system
201: Throttle cable
202: Input cable
203: Start assist cable
204: Solenoid actuator
205: Cable link bridge
206: Electronic control unit (ECU)
301-308: Flowchart for working start assist system