TECHNICAL FIELD
The present invention relates to a throttle body for use in vehicles.
BACKGROUND
The information in this section merely provides background information related to the present disclosure and may not constitute prior art(s).
Traffic congestion is a condition on transport networks that occurs as use increases, and is characterized by slower speeds, longer trip times, and increased vehicular queueing. When traffic demand is great enough that the interactions between vehicles slows the speed of the traffic stream, this results in congestion. Thus, a vehicle has to move at a slower speed in lower gears. A vehicle, for example, may be a two wheeler, a three wheeler or a four wheeler or any other vehicle powered with an internal combustion engine.
Also, in another scenarios, for example, while climbing uphill or while driving through a bad road condition, a vehicle has to be kept in lower gears. It is observed that while driving a vehicle in lower gears, a jerk(s) may be experienced in movement of the vehicle in lower gears or during changing of gears. Also, jerk may be experienced when throttle is increased or decreased when the vehicle is running in low gears.
In the throttle body, amount of air entering engine of the vehicle is regulated by a throttle valve. The throttle valve indirectly controls a charge (fuel + air) burned on each cycle due to the fuel-injector or carburetor maintaining a relatively constant fuel/air ratio. The driver regulates power delivered by the engine by controlling a throttle opening through an accelerator pedal / grip. At lower gears (especially at the 1st and 2nd gears) a ratio between speed of engine to speed of vehicle is very high. Since, this

ratio is very high, a torque available at wheel of the vehicle is also very high. In this condition, the driver should be careful with the accelerator pedal / grip and therefore with the throttle opening. This is because a marginal change in throttle opening changes the power accordingly. Due to this change, there is increase in torque drastically at the wheels as above said ratio is very high in the lower gears. As a result, a sudden jerk is experienced by the driver of the vehicle. This gives a bad ride experience to the driver of the vehicle.
One of the solutions to this problem is to run/drive the vehicle in half clutch so that it may avoid receiving high torque at the wheels of the vehicle. However, this approach suffers from certain drawbacks. For example, the clutch may wear out fast, low life of drive chain, sprocket and clutch, abnormal loading of gears. Additionally, life tyre (s) is also reduced due to the absorption of high jerks/shocks due to abrupt torque delivery.
The other existing solutions include a proper selection of throttle body based on target priority. For example, either a "low" or a "high" venturi throttle body is chosen. The terms "low" and "high" indicates a cross-section area of venturi outlet through which the air passes to engine of the vehicle. High venturi throttle body have higher power but low end torque. It may not provide a good drivability or sluggish response and a high jerking can occur. However, a maximum power and speed can be achieved. On the other hand, low venturi throttle body provides high low end torque. Although this type of throttle body provides a good drivability with reduced jerking but a low maximum power and speed.
Figure 1 illustrates a conventional throttle body used in a carburetor according to prior art. As already discussed, a throttle body is a valve located between the air intake filter and the intake manifold. It regulates the amount of air delivered into the engine, based on driver input through the gas/accelerator pedal. As more air flows into the engine, it injects more fuel, thus allowing for more power. The throttle body has a housing (108),

a slider (103), a slider spring (104), a zero-setting screw (106) and a screw spring (107). The housing defines an oval shaped intake passage (102), that allows flow of air towards the intake manifold. The slider (103) is slidably disposed in the housing and arranged to slide inside the housing to open or close the intake passage to regulate flow of air through the intake passage. In FIG. 1 a conventional throttle valve with an oval shaped throttle opening is shown. However, other conventional throttle valves may include a circular opening in place of an oval opening.
The throttle body (101) further comprises the bolt (106) and the spring (107) for the zero setting of the slider (103). FIGs. l(a)-(c) illustrate movement of the slider inside the housing between an open position, an intermediate position and a closed position. Initially, when the vehicle is stationary, the slider (103) is at its initial closed position i. e. the throttle opening is closed, as shown in FIG. 1(a). When the vehicle is started and is driven in lower gears (e.g. 1st or 2nd), the throttle is opened up slightly from the fully closed position towards the open position, as shown in FIG. 1(b). Further, the throttle can be fully opened as shown in FIG. 1(c).
At the lower gears, especially in the 1st and 2nd gears, a ratio between speed of engine to speed of vehicle is very high. Since, this ratio is very high, a torque available at wheel of the vehicle is also very high. In this condition, the driver is required to be careful with the accelerator control or with the throttle opening. The throttle openings in conventional throttle bodies are generally substantially symmetrical with respect to a plane perpendicular to the direction of movement of the slider. Due the oval shape/circular shape of the throttle opening, a marginal change in throttle opening changes the power delivery by the engine drastically. More precisely, charge flow with respect to the marginal change in throttle opening is non-linear. Due to this change, there is increase in torque drastically at the wheels as the above said ratio is very high in the lower gears. Therefore, in lower gears, where the engine speed to vehicle speed ration is high, slight change of throttle input in lower gears results in sudden change in

engine speed and accordingly, sudden change in power delivery to the wheels. Thus, a rider/driver feels jerk while moving in lower gears.
The present disclosure addresses one or more problems as discussed above or other problems associated with the throttle bodies known in the art.
SUMMARY
A throttle body for an internal combustion engine including a body defining an intake passage, a slider disposed in the body, the slider configured to move in a direction orthogonal to a flow in the intake passage between an open position and a closed position to open and close the intake passage, respectively. Wherein a cross section of the intake passage is asymmetric with respect to a plane perpendicular to the direction of movement of the slider.
In an aspect, the cross-section is elongated in the direction of movement of the slider.
In an aspect, the elongated cross-section has a first end and a second end disposed along a longitudinal length of the cross-section, the first end being narrower compared to the second end.
In an aspect, the slider is configured to move from the broader end towards the narrower end to gradually close the intake passage, and from narrower end towards the broader end to gradually open the intake passage.
In an aspect, the slider is cylindrical in shape with cylindrical axis disposed in the direction of movement of the slider.
In an aspect, the body adapted to be attached to a carburetor.

In an aspect, the throttle body has a cap configured to be removably attached to the throttle body, the cap being removable to place slider inside the body.
In an aspect, the throttle body has a slider spring disposed between the cap and the slider to bias the slider towards the closed position.
In an aspect, the throttle body has a zero-setting screw movably disposed in the body, the screw being operable to set a default closed position of the slider.
In an aspect, the throttle body is at least partially made of metal.
BREIF DESCRIPTION OF DRAWINGS
Further aspects and advantages of the present invention will be readily understood from the following detailed description with reference to the accompanying drawings. Reference numerals have been used to refer to identical or similar functionally similar elements. The figures together with a detailed description below, are incorporated in and form part of the specification, and serve to further illustrate the embodiments and explain various principles and advantages, in accordance with the present invention wherein:
Figure 1 (a)-(c) illustrate a throttle body according to prior art.
Figure 2 illustrates an embodiment of a throttle body in closed position in accordance with the present disclosure.
Figure 3 illustrates an embodiment of a throttle body in an intermediate position in accordance with the present disclosure.

Figure 4 illustrates an embodiment of a throttle body in an open position in accordance with the present disclosure.
Figure 5 illustrates a graph comparing the gradual opening in a conventional throttle body with the throttle body in accordance with the present disclosure.
Figure 6 illustrates the change in engine speed with respect to change in throttle/load over time.
DETAILED DESCRIPTION
Before describing in detail embodiments, it may be observed that the novelty and inventive step that are in accordance with the present invention reside in construction of the throttle body, accordingly, the drawings are showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.
The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, device that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such setup or device. In other words, one or more elements in a system or apparatus proceeded by "comprises... a" does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus.
FIGs. 2-4 illustrate a throttle body (10) according to an embodiment of the present disclosure that controls entry of air fuel mixture in the combustion chamber of the

engine by way of providing an asymmetric shaped throttle opening, to reduce jerks felt by a rider/driver, thereby providing a smooth ride experience to the rider/driver.
As shown, the throttle body (10) has a housing (12), a slider (14), a cap (16), a zero-setting screw (18), a slider spring (20), and a screw spring (22). The housing (12) at least partly defines an intake passage (24) to allow flow of air towards an intake manifold of an engine. The intake passage (24) includes a throttle opening (26). The throttle opening (26) as shown in FIGs. 2-4 is elongated having a first end (28) a second end (30) disposed along the longitudinal axis (34) or its longitudinal length of the throttle opening (26). As shown, the first end (28) is narrower compared to the second end (30).
The slider (14) is movably disposed inside a cavity (32) defined in the housing (12) such that the throttle opening (26) can be closed/opened by actuating the slider (14) inside the cavity (32). The slider (14) is shown as cylindrical in shape. The slider (14) is placed in the housing (12) such that the slider (14) is configured to move in a direction along its cylindrical axis. The cylindrical axis of the slider (14) may be substantially parallel to the longitudinal axis of the throttle opening (26). The slider (14) moves or slides along its cylindrical axis to move between an open position to open the throttle opening (26) and a closed position to close the throttle opening (26). FIG. 2 illustrates the slider (14) in closed position, FIG. 3 illustrates the slider (14) in an intermediate position that lies between the closed position and the open position, and FIG. 4 illustrates the slider (14) in the open position. The first end (28) of the throttle opening (26), i.e. the narrower end is positioned towards the closed position. The speed of movement of the slider (14) may be dependent on the throttle input received from a rider/driver. Further, the slider (14) as shown herein is of cylindrical shape, in an alternate embodiment, the slider (14) may be any other shape, for example, cuboidal shape, a flat rectangular plate, or any other suitable shape.

Further, as illustrated, the cap (16) is provided to close the cavity (32) in which the slider (14) is disposed. The cap (16) may be removably attached to the housing (12) using threads or any other suitable arrangement. The cap (16) may be provided with an opening to receive an actuating member that is attached to the slider (14) to actuate the slider (14) between the open position and the closed position. In an embodiment, the actuating member may be a cable directly or indirectly coupled to a throttle grip/pedal of the vehicle. The slider (14) moves from the narrower first end (28) towards the broader second end (30) to open the throttle opening (26) and the slider (14) moves from the second end (30) towards the first end (28) to close the throttle opening (26). The slider (14) may move gradually between the open position and closed position to gradually open/close the throttle opening (26). This may be achieved by gradual pulling/releasing of the cable as known in the art. In an alternate embodiment, the slider (14) may be actuated using any other suitable mechanism such as electronic throttle control.
The slider spring (20) is placed in the cavity (32) and positioned between the cap (16) and the slider (14) to bias the slider (14) against the cap (16), towards the closed position. Accordingly, unless an external force is applied to move the slider (14) towards the open position, the slider (14) remains in closed position under the biasing force of the slider spring (20).
The zero-setting screw (18) provides for a default closed position for the slider (14). The closed position may be adjusted to set the engine idling or the minimum opening of the throttle opening (26). The screw spring (22) is positioned between the screw head and the housing (12) to bias the screw head against the housing (12), as known in the art.

As shown in FIGs. 2-4, the throttle opening (26) is asymmetric with respect to a plane perpendicular to the direction of movement of the slider (14). The first end (28) of the throttle opening (26) is triangular in shape with apex located on the closed end and the base towards the intermediate position. Whereas the shape of the throttle opening (26) towards the second end (30) is substantially rectangular or part oval. Accordingly, the change in opening of the throttle opening (26) (available cross-section of the throttle opening (26) for allowing flow of air towards the intake manifold) with respect to the movement of slider (14) is not substantially linear throughout the movement of the slider (14) between the open position and the closed position. The following table shows comparison of rate of change of the throttle opening (26) with respect to movement of the slider (14) between the conventional throttle body and the throttle body (10) as compared to the present disclosure:

Slider stroke opening
Throttle
Opening
mm Throttle opening
% Asymmetrical
THB Area
mm2 Asymmetrical THB Area
% Symmetrical
THB Area
mm2 THB
Opening
% Difference in %
1 3.9 4.50 1.17 5.46 1.42 0.25
2 7.8 12.39 3.23 15.18 3.95 0.73
3 11.6 22.11 5.76 27.36 7.12 1.37
4 15.5 33.00 8.59 41.29 10.75 2.16
5 19.4 44.64 11.62 56.51 14.72 3.10
6 23.3 56.93 14.82 72.68 18.93 4.11
7 27.1 69.87 18.19 89.50 23.31 5.12
8 31.0 83.47 21.73 106.73 27.80 6.07
9 34.9 97.72 25.44 124.11 32.33 6.88
10 38.8 112.63 29.32 141.51 36.86 7.53

11 42.6 128.20 33.38 158.91 41.39 8.01
12 46.5 144.42 37.60 176.31 45.92 8.32
13 50.4 161.30 41.99 193.71 50.45 8.46
14 54.3 178.76 46.54 211.11 54.99 8.45
15 58.1 196.59 51.18 228.51 59.52 8.34
16 62.0 214.53 55.85 245.91 64.05 8.20
17 65.9 232.57 60.55 263.31 68.58 8.03
18 69.8 250.57 65.24 280.66 73.10 7.86
19 73.6 268.57 69.92 297.85 77.58 7.65
20 77.5 286.57 74.61 314.53 81.92 7.31
21 81.4 304.57 79.29 330.57 86.10 6.80
22 85.3 322.57 83.98 345.56 90.00 6.02
23 89.1 340.43 88.63 359.19 93.55 4.92
24 93.0 357.64 93.11 370.94 96.61 3.50
25 96.9 373.49 97.24 380.02 98.98 1.74
25.8 100.0 384.11 100.00 383.95 100.00 0.00
FIG. 5 illustrate a graph indicating depicting the above comparison. As shown, the conventional throttle body with a conventionally shaped venturi exhibits a substantially linear relation ship with the movement of the slider (14). Whereas, with the throttle body (10) with an asymmetric venturi in accordance with the present disclosure, the change in throttle opening (26) is non linear with respect the change in throttle opening (26). Initially, when the slider (14) starts moving from closed position to the open position, the rate of change in throttle opening (26) is slower as compared to the rate of change in throttle opening (26) at later stage. For example, if the intermediate stage of the slider (14) is considered as a middle position, the rate of change in throttle opening (26) up till the slider (14) moves to the intermediate position, is slower compared to the

rate of change in throttle opening (26) during the movement of the slider (14) from the intermediate position towards the open position.
The slower rate of change in throttle opening (26) at the initial stage allows for slow and gradual change in engine speed. Therefore, the sudden or abrupt changes in the engine speed can be avoided by providing a narrower cross-section of the venturi at the initial stage as compared to the later stage.
For example, due to traffic congestion or bad road conditions, the driver has to move at a slower speed in lower gears. Initially, when the vehicle is stationary, the slider (14) (203) is at its initial position i. e. the slider (14) is in the closed position as shown in FIG. 2. At the lower gears, for movement of the vehicle, the throttle is opened up slightly from the fully closed position towards the open position. Due to the asymmetric shape of the throttle opening (26), specifically at the first end (28) (triangle shaped) of the throttle opening (26), a marginal change in throttle opening (26) causes smooth change or lower rate of change in the charge flow. This smooth change in charge does not add any abrupt additional torque at the wheels. As a result, the sudden jerk which is caused due to the sudden high torque delivery at the wheels of the vehicle is eliminated or reduced. Thus, the driver experiences a smoother drive in low gears.
The foregoing description of the various embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the present disclosure. It is therefore contemplated that the present disclosure covers any and all modifications, variations or equivalents that fall within the scope of the basic underlying principles disclosed above.

List of Reference Numerals
Throttle body (10) Housing (12) Slider (14) Cap (16)
zero-setting screw (18) slider spring (20) screw spring (22) intake passage (24) throttle opening (26) first end (28) second end (30) cavity (32) Longitudinal axis (34)

WE CLAIM:
1. A throttle body (10) for an internal combustion engine, comprising:
a housing (12) defining an intake passage (24);
a slider (14) disposed in the housing (12), the slider (14) configured to move in a direction orthogonal to a flow in the intake passage (24) between an open position and a closed position to open and close the intake passage (24), respectively;
wherein a cross section of the intake passage (24) is asymmetric with respect to a plane perpendicular to the direction of movement of the slider (14).
2. The throttle body (10) as claimed in claim 1, wherein the cross-section is elongated in the direction of movement of the slider (14).
3. The throttle body (10) as claimed in claim 2, wherein the elongated cross-section has a first end (28) and a second end (30) disposed along a longitudinal length of the cross-section, the first end (28) being narrower compared to the second end (30).
4. The throttle body (10) as claimed in claim 3, wherein the slider (14) is configured to move from the broader end towards the narrower end to gradually close the intake passage (24), and from narrower end towards the broader end to gradually open the intake passage (24).
5. The throttle body (10) as claimed in claim 1, wherein the slider (14) is cylindrical in shape with cylindrical axis disposed in the direction of movement of the slider (14).
6. The throttle body (10) as claimed in claim 1, wherein the housing (12) is adapted to be attached to a carburetor.

7. The throttle body (10) as claimed in claim 1, comprising a cap (16) configured to be removably attached to the throttle body (10), the cap (16) being removable to place slider (14) inside the housing (12).
8. The throttle body (10) as claimed in claim 7, comprising a slider spring (20) disposed between the cap (16) and the slider (14) to bias the slider (14) towards the closed position.
9. The throttle body (10) as claimed in claim 1, comprising a zero-setting screw (18) movably disposed in the housing (12), the zero-setting screw (18) being operable to set a default closed position of the slider (14).
10. The throttle body (10) as claimed in claim 1, wherein the throttle body (10) is at least partially made of metal.