US3695244A

US3695244A - Fuel regulating devices for internal combustion engines

Info

Publication number: US3695244A
Application number: US22784A
Authority: US
Inventors: Andre Vauille
Original assignee: Gen Mecanique Applique S I G M
Current assignee: Gen Mecanique Applique S I G M; Soc Ind Generale De Mecanique Applique Sigma
Priority date: 1969-03-25
Filing date: 1970-03-26
Publication date: 1972-10-03
Anticipated expiration: 1989-10-03
Also published as: GB1298726A; FR2036587A6; DE2014486A1

Abstract

The regulating device includes an active element, sensitive to the speed of rotation of the engine, an adjusting element for the flow of fuel per revolution connected to the active element, a sleeve connected flexibly to the active element and a linking mechanism attached on the active element, the sleeve and the adjusting element. Means for the setting of several values of the flow include a member provided with two inclined ramps and stop means provided with two ramps complementary to the preceding ramps. The regulating device may be of ''''any speed'''' or of the ''''mini-maxi'''' type. It can include control means which can be servocoupled to a parameter such as the density of the fuel used by the engine.

Description

Unite Vauilie FUEL REGULATING DEVICES FOR INTERNAL COMBUSTION ENGINES Andre Vauille, Lyon, France I Assignee: Societe lndustrielle Generale de Mecanique Applique S.I.G.M.A., Paris, France Filed: March 26, 1970 App]. No.: 22,784

Inventor:

Int. Cl. ...F02d 1/04, FO2d 1/06 Field of Search ..123/140 US; 1/140 R, 97 R References Cited UNITED STATES PATENTS 8/1961 Evans ..123/140 us Primary Examiner-Wendel] E. Burns Attorney-Waters, Roditi, Schwartz & Nissen [5 1 I ABSTRACT The regulating device includes an active element, sensitive to the speed of rotation of the engine, an adjusting element for the flow of fuel per revolution connected to the active element, a sleeve connected flexibly to the active element and a linking mechanism attached on the active element, the sleeve and the adjusting element. Means for the setting of several values of the flow include a member provided with two inclined ramps and stop means provided with two ramps complementary to the preceding ramps. The regulating device may be of any speed or of the mini-maxi type. It can include control means which can be servocoupled to a parameter such as the density of the fuel used by the engine.

12 Claims, 9 Drawing Figures v m m mm Oct. 3, 1972 PATENTEDUBI 3 I972 SHEET 1 [IF 5 FUEL REGULATING DEVICES FOR INTERNAL COMBUSTION ENGINES The present invention relates to improvements in fuel flow regulating devices for internal combustion engmes.

More particularly the invention relates to improvements in fuel flow regulating devices for internal combustion engines comprising an active element sensitive to the speed of rotation of the engine, adapted to be moved in a rectilinear direction, and a regulating element for the flow of fuel per revolution, connected to said active element, and elastic return means for said active element, mounted on a rod substantially parallel to the said rectilinear direction, which rod is mounted on a support so that its position in the said rectilinear direction is adjustable, which enables adjustment of the flow of fuel per revolution.

Adjusting devices are known in which said rod is screwed into the support and blocked by a lock-nut. The position of this rod, in the said rectilinear direction, can thus be regulated by screwing or unscrewing of the rod in the support, but it is practically impossible to set rapidly a pre-adjusted value of the flow of fuel.

It is an object of the invention, particularly, to render such regulating devices such that they enable rapid setting of at least two valuesof the fuel flow per revolution. I

According to the invention, a regulating device for hand, setting means for at least two values of flow per revolution, mounted on the rod and comprising a member provided with an inclined ramp, on the other hand, stop means mounted on the support of therod and including an inclined ramp complementary to the preceding one and elastic return means urging towards one another the said setting and stop means, the assembly being such that the co-operation of the ramps, on rotation of the member with respect to the support, causes a displacement of the rod and a variation of the set value of the flow per revolution.

Advantageously, the regulating device comprises control meansfor the said member, adapted to turn it progressively and to hold it in positions in and for which the abovesaid inclined ramps cooperate so that the rod can occupy longitudinal positions of adjustment as close to one another as desired, and so that the set values of the flow per revolution are continuously variable.

The control means of the abovesaid member can be servocoupled to a parameter such as, for example, the density of the fuel used by the engine.

The invention consists, apart from the features outlined above, -of certain other features which are used preferably at the same time, and which will be more explicitly considered below as regards preferred methods of construction of the invention which will now be described in more detailed manner, with reference to the accompanying drawings but which are in no way limiting.

FIGS. 1, la and lb of these drawings show, in section, an any speed regulating device, constructed ac cording to the invention;

FIG. 2 shows partially, in section, a regulating device of the mini-maxi type, constructed according to the invention;

FIG. 3 shows in perspective said member provided with an inclined ramp and stop means;

FIG. 4 shows, similarly to FIG. 3, a variation of the abovesaid member and stop means;

FIG. 5 is an end view, with respect to FIGS. 1 and 2 of the regulating device showing, in diagrammatic manner, a control of the setting means;

FIG. 6 shows another embodiment of a alternative control to that of FIG. 5; and lastly,

FIG. 7 shows diagrammatically a regulating device in which the setting means are actuated by a servomotor.

In FIG. 1 there is shown an embodiment of a any speed regulating device for internal combustion engine, constructed according to the invention.

The regulating device as a whole includes the following parts, already known.

A centrifugal regulator 10 is mounted on a coaxial shaft 20, driven by the internal combustion engine (not shown). The regulator includes an active element 3a, or receiver plate, free in translation with respect to the shaft 2a with which it turns. A sleeve 4a is connected in translation with the receiver plate 3a due to a thrust bearing 5la,'but immobilised in rotation.

The plate or chuck 3a, under the centrifugal effect acting on the ball weights 7a, is displaced inav rectilinear direction indicated by the double arrow D, in a direction A when the rotary speed increases and, under the effect of elastic return means, in a direction B when the speed diminishes, the directions being noted on the figure by arrows surmounted by the letters concerned.

A cup element 6a is mounted free in translation on a guide-rod 8a, coaxial with the shaft 2a, mounted on a support constituted by the casing 9a.

A second cup element 10a is mounted at the end, inside the casing, of the rod 8a. This second cup comes into abutment against a shoulder 1 la.

A spring 5a, called overload spring, constituting first elastic means is compressed between the cup 6a and a sleeve 4b which will be defined below.

Advantageously, springs 13a and 14a, respectively called highspeed spring and slow-speed spring, also form part of said first elastic means and are arranged between the cups 6a and 10a.

An accelerator fork 15a mounted on a shaft 16a can, by its rotation, displace the cup 6a along the rod 8a. Two stops 17a and 18a are provided to limit the travel of the fork respectively at low and high speeds.

A regulating element for the flow of fuel per revolution of the pump feeding the engine is constituted by a rack 19a with axis parallel to that of the shaft 20. This rack can be displaced, along its axis, in a direction PLUS indicated by an arrow surmounted by the sign (FIG. 1) and to actuate an increase of the flow, or be displaced in the direction MINUS" (arrow to actuate a reduction of flow.

The sleeve 4b is coaxial and connected elastically to the receiver chuck 3a.

Flexible connection is ensured by a helical spring 29a compressed between the

flats

52a and 12b, abuting respectively against the shoulders of the sleeves 4b and 4a, the latter sleeve being, as will be recalled, connected in translation with the receiver plate 3a. A portion of the sleeve 4b traverses the inside of the sleeve 4a. A washer 43, anchored in the end of thesleeve 4b which is situated, with respect to the sleeve 4a, on the opposite side to that of the spring 29a, serves as stop in the direction B for this latter sleeve. The sleeves 4a and 4b are arranged so that they can approach one another by a distance Xa (FIG. 1), by compressing the spring 29a, before the sleeve 4a abuts against the ring 12b.

The connection mechanism between the rack and the receiver plate is constituted by a lever 30a (FIGS. 1a and lb) hinged, on one hand, in its median part, on a shaft 31a borne by the sleeve 4b and, on the other hand, at one of its ends, on a shaft 44 borne by a part 12a having an arm fixed to the sleeve 4a. The other end of the lever is hinged on one end of a rigid member 70 mounted in its median part, on a fixed axis 71 rigidly fixed to the casing 90. The other end 73 of the member 70 is connected to the rack 19a.

The operation of such a device will be briefly related.

It is assumed that the accelerator fork 15a is supported on the stop 18a and hence that the cup 6a is displaced to the maximum towards the cup 100, compressing on this account to the maximum the springs 13a and 14a and the spring a.

As soon as the engine turns by itself, there is a tendency to take up speed since the flow of fuel per revolution which is provided to it is considerable.

The receiver plate 3a will be moved in the direction A.

The initial compression of the spring 29a is such that the sleeves 4a and 4b, and hence the receiver plate 3a and the sleeve 4b, remain immobile with respect to one another as long as an inner shoulder of the sleeve 4b has not come into abutment against the cup a and the centrifugal force, of direction A, acting on the sleeve 4a, is not at least equal, in absolute value, to the compressive force of the spring 29a.

As long as these conditions are fulfilled, the plate 3a and the sleeves 4a and 4b are displaced together in the direction A. The shaft 44-is immobile with respect to the sleeve 4b. Hence the abovesaid lever (not shown) undergoes a translation of direction A, which displaces in the same direction the end (not visible) of the member 70. This latter will turn in the anti-clockwise direction around the axle 71 and the end 73 will be displaced with the rack 19a, in the direction contrary to the direction A that is to say in the direction MINUS.

For a rotary speed of the engine equal to the slow speed N, or greater to this latter, the conditions previously outlined are fulfilled and the sleeve 4a will approach the sleeve 4b by compressing the spring 29a until it comes into abutment against the flat 12b. The axle 44 will be displaced with respect to the sleeve 4b in the direction A and, due to this, the rack 19a will be displaced in the same direction as A, that is to say in the direction PLUS. This reversal of movement is pursued up to a rotary speed N,, for which the sleeve 40 comes into contact with the ring 12b.

Finally, for a rotary speed N called cut-off speed, the whole of the plate 3a, the sleeves 4a, 4b supported against one another, of the abovesaid lever (not shown) and of the cup 10a will be displaced as a block in the direction A, causing a displacement of the rack in a direction contrary to the direction A, that is to say in the direction MINUS.

The description and the operation of an any speed" regulation device having been explained to establish the ideas, there will be described now the means of the invention proper.

The regulating device comprises setting means b for at least two values of the flow of fuel per revolution of the engine. These means 75b are mounted on the rod 8a and include a member 78b provided with two inclined ramps 79b (FIG. 3). The device includes also stop means 76b mounted on the support 9a and including two inclined ramps 790 (FIG. 3) complementary to the ramps 79b.

The member 78b is advantageously constituted by a nut screwed on a threaded portion 87b belonging to a stop bush 77b, mounted on the rod 8a.

This bush 77b, in the form of a cylindrical sleeve, includes a portion 86b of small outer diameter and the portion 87b of greater outer diameter, this latter portion being threaded internally and externally. The nut 78b co-operates with the outer threading of the portion 87b, whilst the end of the rod 80 opposite to the cup 10b, and situated outside of the casing 9a, bears a threading which co-operates with the inner threading of the abovesaid portion 87b. A shoulder 88b is formed at the connection of the portions 86b and 87b.

Locking of the nut 78b on the portion 87b is ensured by a lock-nut 92b. Locking of the bush 77b on the threaded end of the rod 8a is ensured by a lock-nut 89b.

Stop means 76b are constituted essentially by a cylindrical sleeve 80b of which one portion is located in a bore 81b, coaxial with the rod 8a and provided in the support 9a.

The sleeve 80b bears, at its end situated outside the casing 90, a flange 82b (FIG. 3) approximately in the form of a lozenge, so that two diametrically opposite ears 83b project on the cylindrical wall of the sleeve 80b. These ears are pierced by holes which enable the fixing of the stop means 76b on the casing 9a.

The surface of the flange 82b opposite the sleeve 80b bears two ribs 85b, of rectangular transverse section and of average line in an arc of a circle, extending each over a little less than a semi-circular arc. These two ribs are symmetrical with respect to the axis of the sleeve 80b and end, at two of their diametrically opposite ends, by two symmetrical inclined ramps 790. In a similar manner, the nut 78b of which the shape is substantially of a cylinder, includes the two diametrically opposite inclined ramps 79b. These ramps 79b constitute the ends of the diametrically opposite bosses 91b and adapted to come to be housed in the peripheral spaces existing between the ribs 85b of the stop means 76b.

An inner shoulder 800 extends over the sleeve 80b between the ribs 85b and the bore of the said sleeve.

A control lever b is provided (FIG. 3) rigidly fixed to the nut 78b and extending in a plane perpendicular to the axis of the said nut. A protective cap 93b (FIGS. 1 and 2) rigidly fixed to the nut 78b, is also provided.

Elastic return means, constituted by a helical spring b, urge towards one another the abovesaid setting 75b and stop 76b means. The spring 95b is compressed between an inner shoulder of the sleeve 80b and a ring 94b anchored to the inner end of the portion 86b of the bush 77b.

The casing 9a being generally filled with fluid, sealing joints are provided to avoid any leak from the inside of the casing to the outside.

The operation of the device is as follows. It will be recalled that adjustment of the longitudinal position of the rod 8a enables the adjustment of the flow of fuel per revolution when the engine is running. Modification of the longitudinal position of the rod 8a (or 8b) modifies the initial longitudinal position of the cup 10a (10b) which serves a stop, for the sleeve 4b (3b). Modification of the longitudinal equilibrium position of the sleeve 4b (3b) results in modification of the position of the rack 19a, by reason of the linkage provided by the mechanism 70, the shaft 44 and the part 12a, between the said sleeve 4b and the rack 19a.

To adjust the flow per revolution when the fuel used is for example gasoline, the lever 90b is first of all turned so that the bosses 91b come to be situated in the peripheral spaces existing between the ribs 85b. The bush 77b comes into abutment by its shoulder 88b against the guide 76b (FIG. I). The adjustment of the flow of gasoline is then effected by screwing or by unscrewing the rod 8a in the bush 77b to respectively increase or diminish the flow. The adjustment completed, the bush 77b is locked on the rod 8a by the countemut 89b.

To adjust the flow per revolution when the fuel used is for example gas-oil, the lever 90b is first of all turned so that the ramps 79b of the bosses 91b co-operate with the ramps 79c of the ribs'85b and, at the end of rotation, the surfaces of said bosses and ribssituated respectively in a plane perpendicularto the common axis of the sleeve 80b and the nut 78b are supported against one another. This rotation has determined a displacement of the rod 8a in the direction A. The flow proper of the gas-oil is then adjusted by screwing or by unscrewing the bush 77b in the nut 78b, the rod 80 being rigidly fixed to the bush 77b, according as it is desired to increase or reduce the flow. F inally'the bush 77b is locked on the nut 78b by means of countemut It is envisaged that the amplitudes of the adjustments are limited by judiciously determined heights of the ribs 85b and of the bosses 91b. In fact, it is necessary, when it is in the gasoline position, that the shoulder 88b of the bush 77b be supported against the guide 76b. Now, if the bush 77b was unscrewed too much in the nut 78b, this latter could come into abutment, in the gasoline" position (FIG. 1), against the guide 76b, before the bush 77b, in which case the flow of gasoline could not be adjusted independently of the gas-oil flow. But, in normal operation, this cannot occur by reason of the judicious choice of the said heights of the ribs and of the bosses.

By means of the lever 90b and of the assembly constituted by the guide 76b, the bush 77b and the nut 78b, there can thus, on one hand, be adjusted two values of flow independently of one another and, on the other hand, set instantly by rotation by a quarter of a turn one or other of the adjusted flows.

In FIG. 2 there is shown, partially, a mini-maxi adjustment device constructed according to the invention. The elements of this mini-maxi device identical with elements already described of the any speed device of FIG. 1, are denoted by the same references that is to say by the same figure followed by the same letter. The elements of the minimaxi device playing a similar role to the elements already encountered in the any speed device of FIG. 1 are denoted by a reference of which the figure is identical to that of the reference of FIG. 1, but of which the letter is different.

The helical spring 5b of the mini-maxi device, similar to the spring 5a of the any speed" device is compressed between the receiver plate 3b and a cup 100, coaxial with the rod 8b and held in the direction A by an adjustable stop 101 mounted in the support 9b. This spring Sb acts continuously on the receiver plate 3b. On the other hand, the spring 13b only comes into action when the plate 3b moved sufficiently in the direction A to come into co-operation, by an inner shoulder 102, with the cup 10b. When at rest, the distance separating the shoulder 102 from the cup 10b if equal to e.

It will be noted that the sleeve b shown on FIG. 2 is longer than the sleeve 80b of FIG. 1. In the case of FIG. 2' (mini-maxi device) the sleeve 80b is extended towards the inside of the casing 96 and serves as a sliding guide for the, cup 100.

It will also be noted that the cup 6b of FIG. 2 is supported against a stop fixed with respect to the rod 8b, contrary to the case of the cup 6a of FIG. 1.

The operation of a device of the mini-maxi type is briefly recalled. Such an adjustment device only acts on the flow of fuel admitted to the engine in two extreme ranges of speed of this engine, that is to say in a range of minimum speeds (slow speed) and a range of maximal speeds. The operator alone acts on the flow, due to an accelerator control member, in the whole range of intermediate speeds.

In the range of minimal speeds (slow speed), the spring 5b is alone to act on the receiver plate 3b. In the range of maximal speeds, the shoulder 102 of the plate 3b has come into contact with the cup 10b and the spring 13b, or high speed spring, acts conjointly with the spring 5b on the plate 3b. When the rotary speed of the engine exceeds apredetermined limit, the force exerted on the plate 3b is sufficient to overcome the force developed by the springs 13b and 5b, and push the cup 10b in the direction A. This displacement of the plate 3b in the direction A actuates a reduction of the flow per revolution and a reduction of the rotary speed of the engine.

From this brief recount, it appears thus that, on one hand, the maximal speed for which the adjuster actuates a reduction in flow per revolution is determined es-' senti ally by the tension of the spring 13b and, on the other hand, the value of the flow per revolution, at the moment when the adjuster intervenes at maximal speed, is determined by the position in the direction D of the cup 10b, that is to say by the position along the abovesaid direction D of the rod 8b.

To set two values of the flow per revolution, corresponding for example to the case where the fuel used by the engine is petrol and gas-oil, operation is as explained for the any speed device.

When the adjustment operations are ended, to set one of the two adjusted values, it sufiices to act on the lever b and to place it in one of the two positions previously described. The setting of each of these values, previously adjusted, is hence very rapid.

In FIG. 5, there is diagrammatically shown a control device of the lever 90b. This device comprises a pull rod 103 of which one end ends by a button accessible to the operator and of which the other end is connected by a cable 104 to a sleeve 105 mounted rotatably at the end of the lever 90b furthest spaced from the rod 8b. The cable 104 is housed in a sheath 106.

The pull rod 103, in the form of a cylindrical stem, can slide in a guide 107. Stop means, comprising a ball 108 and a spring 109, are provided to hold the pull rod 103 in a predetermined position. Circular grooves 1 10a and 110b, suitably spaced along the direction of the axis of the pull rod 103, are provided at the periphery of this latter to co-operate with the ball, 108 which is pushed into these grooves 110a and llb by the spring 109.

The operation of the device is extremely simple. To the two cut-outs 110a, 11% there correspond two arrest positions of the pull rod 103 for which one or other of the grooves occurs at the level of the ball 108.

To these positions of the pull rod 103 there corresponds two positions of the lever 90b, one of these positions being shown in full line in FIG. 5, and the other position being shown in mixed line. It will be noted that the angular spacing between the two positions of the lever 90b is less than a quarter of a turn. In fact, as can be seen in FIG. 3, it suffices that the rotation of the lever 90b with respect to the stop means 76b are sufficient for the surfaces of the ribs 85b and of the bosses 91b perpendicular to the axis of the rod 8b come into contact with one another. This rotation depends on the inclination of the

ramps

79b, 79c and can be distinctly less than a quarter of a turn.

The distance between the grooves 110a and 11% provided; on the rod 103 is such that the angular clearance of the lever 90b corresponding to this distance enables the setting of the two pre-adjusted values of flow per revolution. Return means (not shown) are provided to bring back the lever 90b in the counterclockwise direction, relative to FIG. 5. To make the lever 90b pass from the position in full line shown in FIG. to the position in mixed line, it suffices to exert a traction on the pull rod 103, to disengage the ball 108 from the groove 1 a, and to bring the groove 1 10b to the level of the ball 108 so that the pull rod 103 occupies its other arrest position. To make the lever 90b pass from the position in mixed line to the position in full line, it suffices to exert a push on the pull rod 103 to disengage the ball 108 from the groove 110b, and the return means act on the lever 90b to bring it back into the position in full line, where the said lever is stopped as a result of the co-operation of the ball 108 and of the groove 110a. I

Naturally, it is possible to provide more than two positions of setting and of adjustment of the value of the flow per revolution.

In particular, there can be envisaged a progressive adjustment. For this, it suffices to provide control means of the nut 78b adapted to turn it progressively. Preferably, as shown in FIG. 4, the

ramps

79b, 79c extend then substantially over a half-tum, so as to enable a sufficient angular range for the adjustment. In this case, the longitudinal position of the rod 8b is determined no longer by the cooperation of surfaces orthogonal to the axis of the rod such as

shoulders

88b and 800, or surfaces of ribs 85b and of bosses 91b, but by the direct co-operation of

ramps

79b and 79c. It is then possible to pass progressively from one value of the flow per revolution to another value. The adjustment is thus continuous and the variation of the values is all the more slight, for a given angular separation, as the inclination of the ramps is less.

Thecontrol of this continuous adjustment can be manual and the control device can be such as shown diagrammatically in FIG. 6. A toothed wheel 111 meshes on a rack 112 which replaces the pull rod 103 of FIG. 5. This rack 112, like the pull rod 103, is connected by the cable 104 to an end of the lever b (not shown in FIG. 6). The control of the toothed wheel 1 1 l is effected manually by means of a member 113 in the form of a lever.

In all cases, there can be substituted for the manual control a remote control. In the case of FIG. 5 (discontinuous values set), this remote control could be constituted'by a hydraulic or pneumatic jack, or by an electromagnet.

In the case of FIG. 6, the rack 112 and the toothed wheel 1 1 1 could be replaced by hydraulic jack enabling a continuous adjustment. Advantageously, servocoupling can be provided of the position of the lever 90b to the value of a parameter. This parameter can be the density of the fuel used by the engine, or the power of the latter.

In FIG. 7, there is shown diagrammatically a servomotor unit 114 sensitive to the abovesaid parameter. Such servomotor units may be constituted by a servomotor (Type A) as described in Dossier Technique de la Mecanique (Feuilles Techniques 7-R 5-6, lere Edit. Nov. 1969, Editions Techniques Paul I-Iuet, 92-Boulogne-Billancourt, France); or by an EG-3P Actuator manufactured by Woodward Governor Company, Rockford Ill. and described in their Bulletin 82505; or by a Sigma Cyclonome Stepping Motor, Series 9AH5 manufactured by Sigma Instruments Inc. of Braintree, Mass, described in their Bulletin RE-l08. According to the values taken by this latter, the servomotor unit 114 gives to the rotary arm 115 various determined angular positions. The arm 115 is connected by a rigid rod 116 to the end of the lever 90b spaced from the rod 8b. The rod 116 is mounted pivotably on the arm 1 15 on the lever 90b.

The servocoupling of the control of the lever 90b can be effected either in the case where the set values of flow are discontinuous, the number of these values being finite and equal to two in the case of FIG. 5, or in the case where the set values of flow are continuous.

As a result, and whatever the embodiment adopted, there is obtained an adjustment device enabling the rapid setting of preadjusted values for the flow of fuel per revolution.

As is self-evident and as results besides already from the preceding description, the invention is in no way limited to those of its methods of application, nor to those of its methods of production of its various parts, which have been more particularly indicated; it embraces, on the contrary, all variations.

What I claim is:

1. Regulating device for the fuel flow per revolution of an internal combustion engine comprising an active element adapted to be displaced in a rectilinear direction from an initial position to a displaced position as a function of the speed of rotation of the engine,

fuel flow adjustment means for the flow of fuel per revolution, connected to the active element,

first elastic means constituted by a spring element urging said active element to said initial position, a

ing control means for said member adapted to cause it to turn and to hold it in positions as close to one another as desired and for which the said inclined ramps cooperate, so that the rod can occupy longitudinal adjustment positions as close to one another as desired and the variations in the said value of the flow 30 per revolution are continuous.

rod substantially parallel to said rectilinear direction on which said elastic means is mounted, a support to which said rod is fixed so that its position along said rectilinear direction is adjustable, which enables adjustment of the flow of fuel per revolution, said device comprising, setting means for at least two set values of the flow per revolution mounted on the rod and including a member provided with at least one first inclined ramp, stop means mounted on said support and including at 10 least one second inclined ramp complementary to said first ramp, and second elastic means urging towards one another said setting means and said stop means, the assembly being such that the cooperation of said ramps, on rotation of said member with respect to said support, causes a displacement of the rod and a variation of said set value.

2. Regulating device according to claim 1, wherein said device is of the any speed type.

3. Regulating device according to claim 1, wherein said device is of the mini-maxi type.

4. Regulating device according to claim 1, compris- 5. Regulating device according to claim 1, wherein said member is constituted by a nut including two diametrically opposite inclined ramps.

6. Regulating device according to claim 5 wherein said nut is provided with a control lever.

7. Regulating device according to claim 4 wherein said member is constituted by a nut including two diametrically opposite inclined ramps, said nut being provided with a control lever and each inclined ramp extends substantially over a semi-circular arc.

8. Regulating device according to claim 4, wherein said member is constituted by a nut including two diametrically opposite inclined ramps, said nut being provided with said control means and said control means comprise a lever, and a toothed wheel which meshes with a rack, this latter being mechanically connected to the lever of the said nut, so that longitudinal displacements of the rack cause rotation of said member.

9. Regulating device according to claim 1, arranged so that the set values of the flow are discontinuous and finite in number.

10. Regulating device according to claim 9, wherein said nut is provided with a control lever and the surfaces of said nut and of said stop means which cooperate to maintain the nut in a predetermined position are perpendicular to said rectilinear direction, so that the co-operation of the inclined ramps only takes place at the moment of passage from the predetermined position of the nut to another, said passage being actuated by a pull-rod connected mechanically to the lever of the nut.

11. Regulating device according to claim 1, wherein said control means comprise servocoupling means,

phase-lockfd to a parameter so that the longitudinal position 0 the rod depends on the value of said parameter.

12. Regulating device according to claim 1 1, wherein said parameter is the density of the fuel used by the engine.

Claims

1. Regulating device for the fuel flow per revolution of an internal combustion engine comprising an active element adapted to be displaced in a rectilinear direction from an initial position to a displaced position as a function of the speed of rotation of the engine, fuel flow adjustment means for the flow of fuel per revolution, connected to the active element, first elastic means constituted by a spring element urging said active element to said initial position, a rod substantially parallel to said rectilinear direction on which said elastic means is mounted, a support to which said rod is fixed so that its position along said rectilinear direction is adjustable, which enables adjustment of the flow of fuel per revolution, said device comprising, setting means for at least two set values of the flow per revolution mounted on the rod and including a member provided with at least one first inclined ramp, stop means mounted on said support and including at least one second inclined ramp complementary to said first ramp, and second elastic means urging towards one another said setting means and said stop means, the assembly being such that the cooperation of said ramps, on rotation of said member with respect to said support, causes a displacement of the rod and a variation of said set value.

2. Regulating device according to claim 1, wherein said device is of the ''''any speed'''' type.

3. Regulating device according to claim 1, wherein said device is of the ''''mini-maxi'''' type.

4. Regulating device according to claim 1, comprising control means for said member adapted to cause it to turn and to hold it in positions as close to one another as desired and for which the said inclined ramps cooperate, so that the rod can occupy longitudinal adjustment positions as close to one another as desired and the variations in the said value of the flow per revolution are continuous.

5. Regulating device according to claim 1, wherein said member is constituted by a nut including two diametrically opposite inclined ramps.

10. Regulating device according to claim 9, wherein said nut is provided with a control lever and the surfaces of said nut and of said stop means which co-operate to maintain the nut in a predetermined position are perpendicular to said rectilinear direction, so that the co-operation of the inclined ramps only takes place at the moment of passage from the predetermined position of the nut to another, said passage being actuated by a pull-rod connected mechanically to the lever of the nut.

11. Regulating device according to claim 1, wherein said control means comprise servocoupling means, phase-locked to a parameter, so that the longitudinal position of the rod depends on the value of said parameter.

12. Regulating device according to claim 11, wherein said parameter is the density of the fuel used by the engine.