EP0409713B1 - Control device for a gas inlet trottle valve for a combustion engine - Google Patents

Description

The present invention essentially relates to a device for controlling a throttle valve for admitting gases into an internal or external combustion engine.

If one refers for example to document FR-A-2 602 004, it can be seen that a device has already been proposed for controlling a throttle valve for admitting gases into a combustion engine and of the type in which an operating pedal is connected to the butterfly by connecting means which in particular comprise a spring element and the part of which situated between the spring and the butterfly is connected to a damper.

However, such a device has a certain number of drawbacks among which one can cite the complexity of the mechanical design and therefore of the manufacturing, as well as the reliability of operation, which is probably random due to the multiplicity of the various elements making up the device.

Also, the present invention aims to remedy these drawbacks by proposing a device for controlling a throttle valve which is of a simplified structure and which advantageously provides damping at the start of opening and closing of the butterfly.

Also known from document FR-A-2 528 113 is a device for controlling an intake throttle of the type described in the preamble to claim 1.

The subject of the invention is a device for controlling a throttle valve for admitting gases into a combustion engine and of the type in which an operating pedal is connected to the throttle valve by connection means which comprise a spring element and the part between the spring and the butterfly is connected to a damper which is mounted between two points of articulation, one of which is articulated on a part pivoting on a fixed axis, the damper being of the single-acting type and arranged so as to act only when its line of action approaches the fixed axis, characterized in that the line of action of the shock absorber passes through said fixed axis when the butterfly is in a position partial opening, and is located on one side or the other of this fixed axis when the throttle is in the large opening or closing position.

According to an exemplary embodiment, this device is further characterized in that the aforementioned articulation point of the damper to the workpiece is integral with a throttle control cable, while the other articulation point this shock absorber is fixed.

It will be specified here that the aforementioned part is constituted by a thrust link.

According to another embodiment, the other point of articulation of the damper is articulated on the end of a lever integral with the butterfly and the other end of which is articulated on the part by means of a link.

In this case, the aforementioned part has a cam shape on which the aforementioned link is articulated.

• La figure 1 illustre schématiquement un dispositif conforme aux principes selon cette invention;
• La figure 2 illustre schématiquement et pour une meilleure compréhension trois positions de l'amortisseur et de la pièce à laquelle est articulé cet amortisseur et correspondant respectivement à une position de ralenti c'est-à-dire de faible ouverture du papillon, à une position d'ouverture plus grande du papillon, et à une position d'ouverture presque totale du papillon ;
• La figure 3 est une vue schématique d'un autre mode de réalisation de dispositif de commande de papillon selon cette invention ; et
• La figure 4 montre trois courbes illustrant respectivement la variation de la longueur de l'amortisseur, l'effort d'amortissement à l'ouverture du papillon et l'effort d'amortissement à la fermeture de ce papillon, en fonction de l'angle d'ouverture de ce dernier.

However, other advantages of the invention will appear better in the detailed description which follows and refers to the appended drawings, given solely by way of example, and in which:

• Figure 1 schematically illustrates a device according to the principles according to this invention;
• Figure 2 illustrates schematically and for a better understanding three positions of the shock absorber and of the part to which this shock absorber is articulated and corresponding respectively to an idle position, that is to say of small throttle opening, to a position of greater throttle opening, and to a position d 'almost complete opening of the butterfly;
• Figure 3 is a schematic view of another embodiment of the throttle control device according to this invention; and
• FIG. 4 shows three curves respectively illustrating the variation in the length of the damper, the damping force at the opening of the butterfly and the damping force at the closing of this butterfly, as a function of the angle opening of the latter.

Referring to Figures 1 and 3, there is shown a device for controlling a throttle valve 1 for admitting gases into a combustion engine, said throttle valve being controlled by an accelerator pedal 2 articulated at 3 on the vehicle.

The pedal 2 is connected to the butterfly 1 by means of an elastic element 4, for example forming a spring. Between the spring 4 and the butterfly 1 is interposed a damper 5 of a type known per se and essentially comprising, as can be seen in Figures 1 and 3 a body 6 in which is housed a deformable membrane 7 biased by a spring 8 and comprising, as is clearly visible in FIG. 3, a restricted orifice 9 establishing permanent communication between the two chambers separated by the membrane 7.

According to the invention, the damper 5 is mounted by its ends between two articulation points 10, 11 one of which 11 is articulated on a part 12 capable of pivoting about a fixed axis 13 so that, as we understand, the line of action of the shock absorber 5 can either pass through the fixed axis 13 or be located on one side or the other of this fixed axis as a function of the pressure exerted on the pedal 2.

According to the embodiment illustrated in FIGS. 1 and 2, the articulation point 11 of the damper 5 to the part 12 is integral with a cable 14 for controlling the throttle 1. This cable 14 is connected at 15 to the pedal 2 and at 16 to a reel 17 for controlling the butterfly valve 1, the latter being biased by a return spring shown diagrammatically at 18. The spring 4 mentioned previously is here interposed on the cable 14 between point 15 and the point of articulation 11 of the damper on the part 12 and on said cable 14.

The other point 10 of articulation of the damper 5 is a fixed point, so that the damper can pivot around this point, just as the articulation point 13 of the part 12 is also a fixed point .

This part 12 is constituted by a push rod, but, for a better understanding of the invention, the following will explain how the device which has just been described works with the aid of FIG. 2.

We will start from the visible rest position in Figure 1, position for which no pressure is exerted on the pedal 2 and for which the articulation points 10, 11 and 13 are not aligned.

If now there is pressure on the accelerator pedal 2, traction will be exerted on the cable 14 via the spring 4 which will cause the displacement of the articulation point 11 and therefore the rotation of the damper 5 around the point 10 and of the link 12 around the point 13. This rotation will cause the rod 19 of the shock absorber 5 will compress the diaphragm 7 of the shock absorber under the action of the thrust link 12. Therefore, it is understood that such compression will oppose a temporary force to the opening of the butterfly, it being understood that the spring 4 interposed between the pedal 2 and the articulation point 11 will integrate the resistance provided by the damper 5. Thus, the rotational movement of the butterfly 1 at the start of opening is damped with respect to the action on the pedal 2, this which significantly improves driving pleasure, because the brutality of the throttle opening is reduced and jolts are avoided.

If one continues to exert a pressure on the pedal 2, it will occur a crossing of the "dead center" constituted by the alignment of the points of articulation 10, 11 and 13, and, in the more depressed position of the pedal 2, the points of articulations 10, 11 and 13 will again be misaligned, but in the opposite position to that shown in FIG. 1, which will in a way cause the shock absorber 5 to relax as the the shock absorber reaches the fully open throttle position 1.

Then, by releasing the pressure of the foot on the pedal 2, the damping effect previously described will again occur, in the opposite direction, that is to say that the start of the closing movement of the butterfly 1 will be damped, which advantageously reduces hydrocarbon emissions.

We therefore understand that the amortization is exercised in the two-way, that is, both when the butterfly opens and closes.

The various movements above are found in Figure 2 where we see in D the race of the cable 14 and in E the compression stroke applied to the damper 5 in the "neutral" position, that is to say say alignment of the articulation points 10, 11 and 13. In this figure, the position of the articulation point 11 corresponding to the idle position has been shown in lia, and at 11b the position of the articulation point 11 corresponding to the "full foot" position on the accelerator pedal 2.

It will be observed here that the initial relative position of the articulation points 10, 11 and 13 defines the maximum compression stroke obtained when these three points are aligned.

In the second embodiment of the device according to this invention and visible in FIG. 3, it can be seen that the cable 14 actuable by the accelerator pedal is connected, via the spring 4, to a part 12 which, here, has the shape of a cam pivoting around the fixed axis 13.

As for the previous embodiment, the articulation point 11 of the rod 19 of the damper 5 is articulated on the part 12.

But here, the other point 10 of articulation of the damper 5 is no longer a fixed point of articulation, but is articulated on the end of a lever 20 secured by its part 20a of the axis 20b throttle valve 1.

As for the other end of the lever 20, it is articulated at 21 on a connecting rod 22 itself articulated at 23 on the part or cam 12.

In other words, it is understood that the butterfly 1 is controlled indirectly by a lever 20 and link 22 system allowing a reduction in the start of opening of the butterfly 1.

There is shown at 24 a spring coupled to the lever 20 and allowing the return in the closed position of the butterfly 1.

It is understood that here, the relative position of the points of articulation 10 and 11 relative to the fixed axes 13 and 20b of the cam 12 and of the butterfly 1 respectively determines the variation in distance which occurs during the movement between the points d hinge 10 and 11. Thus, we can adjust the damping stroke and the angle from which the damping will be applied. As can be seen on the first curve in Figure 4, beyond a certain opening value, the distance between the points of articulation 10 and 11 will stop decreasing, so that the opening of the butterfly will be done without delay.

It should be noted that the amortization will be carried out in a similar way to the return to idling.

In FIG. 4, the starting distance between the points of articulation 10 and 11 has been shown in F, in G the idle position and in H the "full foot" position on the accelerator pedal.

Finally, the two other curves in FIG. 4 clearly illustrate the force provided by the shock absorber when opening and closing the butterfly depending on its opening angle.

It will be noted that the angles for which damping takes place on opening and closing are not necessarily the same.

Thus, the spring 4 can be replaced by another elastic means, for example integral with the connecting rod 22, the latter being able to be produced so as to constitute itself a spring.

Claims (6)

1. Device for the control of a throttle valve for the intake of gases into a combustion engine and of the type in which an operating pedal (2) is connected to the throttle valve (1) by connecting means which comprise an element forming a spring (4) and the portion of which located between the spring (4) and the throttle valve (1) is connected to a damper (5) which is mounted between two pivotal connection points (10, 11), one (11) of which is pivotally connected to a part (12), swinging about a stationary pin (13), of the damper (5) being of the single acting type and disposed so as to only act when its line of action is coming closer to the stationary pin (13), characterized in that the line of action of the damper passes through the said stationary pin when the throttle valve (1) is in a partial open position and is lying on one side or on the other one of this stationary pin (13) when the throttle valve (1) is in a position of great opening or closing.
2. Device according to claim 1, characterized in that the aforesaid point (11) for the pivotal connection of the damper (5) to the part (12) is made fast to a cable (14) for the control of the throttle valve (1) whereas the other pivotal connection point (10) of the damper (5) is stationary.
3. Device according to claim 1 or 2, characterized in that the aforesaid part (12) consists of a thrust link.
4. Device according to claim 1, characterized in that the other pivotal connection point (10) of the damper (5) is pivoted to the end of a lever (20) made fast to a throttle valve (1) and the other end of which is pivotally connected to the part (12) through the medium of a connecting rod (22).
5. Device according to claim 4, characterized in that the aforesaid part (12) exhibits the shape of a cam upon which is winding a cable (14) connected to the pedal by the spring (4).
6. Device according to claim 4, characterized in that the connecting rod (22) is elastic so as to itself constitute the spring-forming element (4).

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