GB2089430A

GB2089430A - I.C. Engine Carburettor Throttle Valve Return Spring Arrangement

Info

Publication number: GB2089430A
Application number: GB8136597A
Authority: GB
Original assignee: Pierburg GmbH
Current assignee: Pierburg GmbH
Priority date: 1980-12-11
Filing date: 1981-12-04
Publication date: 1982-06-23
Also published as: IT8149536A0; DE3046624A1; FR2496171A1; SE8106387L

Abstract

The lever 4 which opens the or each throttle valve 2 to a limit set by a stop 11, against the bias of a spring 10, entrains a lever 5 biased by a spring 7 after an initial valve opening thereby to increase the force necessary to open the valve. The spring 7 biases the lever 5 to engage a lever 6, positioned by a cable 8 or an engine or vehicle speed responsive motor 9, which sets the valve opening angle at which the lever 4 entrains the lever 5. <IMAGE>

Description

SPECIFiCATION Carburettor for Internal Combustion Engines The invention relates to a carburettor for internal combustion engines, with one or more throttle valves, each actuated by the driver of the vehicle, against the influence of a return spring, by means of a pivoted throttle-pedal lever connected to each throttle valve, the forwards rotation of the throttle-pedal lever, in its opening direction, being limited by a stop which is fixed in position relative to the carburettor.

In the operation of internal combustion engines the torque produced by the engine is conventionally regulated, by the operator of the engine, by adjusting, with the help of an accelerator pedal, the angular position of the main throttle valve of the carburettor. If the engine is powering a motor vehicle, the adjustment has to be made with sensitive precision at each instant to suit the existing driving circumstances and this requires that the mechanism for actuating the throttle valve must itself respond precisely.

For example, the German Offenlegungsschrift 28 09 894 describes a mechanism for actuating the throttle valve of a carburettor in a motor vehicle. For improving precision in the driver's control of engine torque, his pivoted accelerator pedal is connected to the pivoted throttle valve of the carburettor in a variable manner, so that when the accelerator pedal is rotated through a given angle this rotates the throttle valve through a second angle, the ratio between the two angles being variable. The arrangement is advantageous in a vehicle powered by an engine capable of delivering very high torques, in that the driver can rotate his accelerator pedal through its full range of movement without producing excessive engine torque, a matter of considerable importance in certain road-surface and traffic conditions.But there is the disadvantage that the highest possible torque is not automatically available from the engine in emergency situations.

A further disadvantage of the known arrangement is that the driver is not provided with any means to enable him to operate the engine, under normal circumstances, within its most efficient power range, in order to keep fuel consumption low.

The iritention in the present invention is to provide means for helping the driver of a motor vehicle to operate his engine, under normal circumstances, within its most efficient power range, in order to keep fuel consumption low, and to enable him volontarily limit the torque taken from the engine. Nevertheless the driver must be able, at each instant on his journey and without delay, to evoke the full available torque from his engine in order to obtain the highest possible acceleration in emergency situations.

The problem is solved, according to the invention, by the characteristics claimed in Claim 1. Advantageous further developments of the invention are described in the subsidiary claims.

What is achieved is that the driver can conveniently drive economically under normal circumstances but can at any time, when necessary, break through the economical range of engine torques by thrusting his accelerator pedal still further forwards, although against a higher spring resistance, and so obtain the higher torques available from the engine. The breakthrough point in the range of travel of the accelerator pedal, i.e. the point where a higher spring resistance is encountered, can be adjusted by manually adjusting a control cable to vary the interposition-position of the second pivoted lever to one or other of its setting positions, depending on the driving circumstances. Furthermore, if desired, the interposition-position of the second pivoted lever can be determined by a positioning motor responsive, for example, to engine speed or vehicle speed.It should be observed that the extra spring resistance encountered at the breakthrough point in the stroke of the accelerator pedal can always be overcome by the driver of the vehicle, whatever setting has been given to the second pivoted lever, whenever an emergency requires the highest possible acceleration to be applied.

The example of the invention shown in the drawing will now be described in greater detail.

The drawing shows the entire mechanism diagramatically. The carburettor has a throttle valve 2 fixed to a pivot pin 3, to which is also fixed a throttle-pedal lever 4, for actuation by the driver of the vehicle against the influence of a return spring 10. Mounted to rotate on the pivot pin 3 are a second lever 5 and a third lever 6, these two levers being connected together by a connecting spring 7. When the second lever 5 is at rest, its lower toe rests in contact with a stop on the lower portion of the third lever 6, whose rotation anticlockwise is limited by a control cable 8, or by a positioning motor 9. Forwards rotation of the throttle-pedal lever 4 in its opening direction (i.e.

anticlockwise as represented in the drawing) is ultimately limited by a fixed stop 11 on the housing of the carburettor 1. Nevertheless, in this forwards rotation, before reaching the fixed stop 11, the throttle-pedal lever 4 encounters a stop 1 2 arranged on the second lever 5.

After that, further forwards rotation of the throttle-pedal lever 4 is opposed by the connecting spring 7 until, ultimately the throttlepedal lever 4 is finally arrested by the fixed stop 11.

Claims

1. A carburettor for internal combustion engines, with one or more throttle valves, each actuated by the driver of the vehicle, against the influence of a return spring, by means of a pivoted throttle-pedal actuated lever connected to each throttle valve, the forwards rotation of the throttle-pedal actuated lever, in its opening direction, being limited by a stop which is fixed in position relative to the carburettor, characterised in that the carburettor (1) has a second pivoted lever (5) capable of being interposed into the path

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFiCATION Carburettor for Internal Combustion Engines The invention relates to a carburettor for internal combustion engines, with one or more throttle valves, each actuated by the driver of the vehicle, against the influence of a return spring, by means of a pivoted throttle-pedal lever connected to each throttle valve, the forwards rotation of the throttle-pedal lever, in its opening direction, being limited by a stop which is fixed in position relative to the carburettor. In the operation of internal combustion engines the torque produced by the engine is conventionally regulated, by the operator of the engine, by adjusting, with the help of an accelerator pedal, the angular position of the main throttle valve of the carburettor. If the engine is powering a motor vehicle, the adjustment has to be made with sensitive precision at each instant to suit the existing driving circumstances and this requires that the mechanism for actuating the throttle valve must itself respond precisely. For example, the German Offenlegungsschrift 28 09 894 describes a mechanism for actuating the throttle valve of a carburettor in a motor vehicle. For improving precision in the driver's control of engine torque, his pivoted accelerator pedal is connected to the pivoted throttle valve of the carburettor in a variable manner, so that when the accelerator pedal is rotated through a given angle this rotates the throttle valve through a second angle, the ratio between the two angles being variable. The arrangement is advantageous in a vehicle powered by an engine capable of delivering very high torques, in that the driver can rotate his accelerator pedal through its full range of movement without producing excessive engine torque, a matter of considerable importance in certain road-surface and traffic conditions.But there is the disadvantage that the highest possible torque is not automatically available from the engine in emergency situations. A further disadvantage of the known arrangement is that the driver is not provided with any means to enable him to operate the engine, under normal circumstances, within its most efficient power range, in order to keep fuel consumption low. The iritention in the present invention is to provide means for helping the driver of a motor vehicle to operate his engine, under normal circumstances, within its most efficient power range, in order to keep fuel consumption low, and to enable him volontarily limit the torque taken from the engine. Nevertheless the driver must be able, at each instant on his journey and without delay, to evoke the full available torque from his engine in order to obtain the highest possible acceleration in emergency situations. The problem is solved, according to the invention, by the characteristics claimed in Claim 1. Advantageous further developments of the invention are described in the subsidiary claims. What is achieved is that the driver can conveniently drive economically under normal circumstances but can at any time, when necessary, break through the economical range of engine torques by thrusting his accelerator pedal still further forwards, although against a higher spring resistance, and so obtain the higher torques available from the engine. The breakthrough point in the range of travel of the accelerator pedal, i.e. the point where a higher spring resistance is encountered, can be adjusted by manually adjusting a control cable to vary the interposition-position of the second pivoted lever to one or other of its setting positions, depending on the driving circumstances. Furthermore, if desired, the interposition-position of the second pivoted lever can be determined by a positioning motor responsive, for example, to engine speed or vehicle speed.It should be observed that the extra spring resistance encountered at the breakthrough point in the stroke of the accelerator pedal can always be overcome by the driver of the vehicle, whatever setting has been given to the second pivoted lever, whenever an emergency requires the highest possible acceleration to be applied. The example of the invention shown in the drawing will now be described in greater detail. The drawing shows the entire mechanism diagramatically. The carburettor has a throttle valve 2 fixed to a pivot pin 3, to which is also fixed a throttle-pedal lever 4, for actuation by the driver of the vehicle against the influence of a return spring 10. Mounted to rotate on the pivot pin 3 are a second lever 5 and a third lever 6, these two levers being connected together by a connecting spring 7. When the second lever 5 is at rest, its lower toe rests in contact with a stop on the lower portion of the third lever 6, whose rotation anticlockwise is limited by a control cable 8, or by a positioning motor 9. Forwards rotation of the throttle-pedal lever 4 in its opening direction (i.e. anticlockwise as represented in the drawing) is ultimately limited by a fixed stop 11 on the housing of the carburettor 1. Nevertheless, in this forwards rotation, before reaching the fixed stop 11, the throttle-pedal lever 4 encounters a stop 1 2 arranged on the second lever 5. After that, further forwards rotation of the throttle-pedal lever 4 is opposed by the connecting spring 7 until, ultimately the throttlepedal lever 4 is finally arrested by the fixed stop 11. Claims

1. A carburettor for internal combustion engines, with one or more throttle valves, each actuated by the driver of the vehicle, against the influence of a return spring, by means of a pivoted throttle-pedal actuated lever connected to each throttle valve, the forwards rotation of the throttle-pedal actuated lever, in its opening direction, being limited by a stop which is fixed in position relative to the carburettor, characterised in that the carburettor (1) has a second pivoted lever (5) capable of being interposed into the path of movement of the throttle-pedal actuated lever (4) so that in its opening movement, after rotating through a first angle determined by the interposition angle adopted by the second lever (5), the throttle-pedal actuated lever (4) encounters the second lever (5); the second lever (5) resting, up till the instant of encounter, in contact with a third pivoted lever (6); the second and third levers (5,6) being connected together by a connecting spring (7); so that with further forwards movement of the throttle-pedal actuated lever (4) this lever drives the second lever (5) forwards with it, the forwards movement of the throttle-pedal actuated lever (4) now taking place against the influence of the connecting spring (7) until, ultimately, the throttle-pedal actuated lever (4) encounters the stop (11) which is fixed in position relative to the carburettor (1).

2. A Carburettor as claimed in Claim 1, characterised in that the second pivoted lever (5) is rotated into its interposition-position or, if desired, into one or other of several alternative interposition positions, by a control cable.

3. A carburettor as claimed in Claim 1, characterised in that the second pivoted lever (5) is rotated into its interposition-position by a positioning motor (9).

4. A carburettor as claimed in Claim 3, characterised in that the positioning motor (9) responds to engine speed.

5. A carburettor as claimed in Claim 3, characterised in that the positioning motor responds to vehicle speed.

6. A carburettor substantially as hereinbefore described with reference to the accompanying drawing.