FR2480853A1 - Hydraulic valve control for IC engine - uses piston controlled by concentric sleeves rotated by engine driven satellite gear train - Google Patents

Abstract

For operating the valves of an internal combustion engine, a single acting hydraulic piston and cylinder (1) has its piston rod (2) controlling a valve. A spring behind the piston (3) pushes it towards an upper position with an outlet (30) communicating with a hydraulic distributor (5). This contains two concentric sleeves (6,7) with pairs of holes (35,36; 33,34) which form entry and discharge points, as the two sleeves are rotated axially, for the supply of hydraulic oil through inlet and outlet lines (24,32). The inner sleeve (7) is connected to a satellite carrier (10) with two satellite wheels (11) of a planet gear driven by the engine. The outer sleeve (6) is connected to a second satellite carrier (8) with two satellites (9).

Description

Hydraulic control of internal combustion engine valves
The invention relates to the control of valves of internal combustion engines.

In order to optimize the operation of internal combustion engines used at variable load and speed, as well as according to other parameters affecting their basis, such as the temperature of the air or cooling water, we consider as desirable to be able to vary the opening angles of the valves, ee that does not allow a conventional control by camshaft, being to see in addition that a variable distribution controlling the filling in air of the cylinders by opening angle poppies eliminates the losses resulting from the rolling of atmospheric air on admission by the usual adjusting butterfly.

The object of the present invention is to control valves with variable distribution for this purpose using an original and relatively simple hydraulic control in consideration of the extent of the possibilities which it brings.

Essentially, for this purpose, the control of internal combustion engine valves according to the invention, is characterized in that it comprises, for each intake or exhaust valve, a hydraulic actuator of the valve , and for all the hydraulic actuators of the intake or exhaust valves, a distributor comprising two concentric cylindrical rotors rotatably mounted in a body comprising, for supplying the actuator of each valve, hydraulic fluid intake orifices under pressure and exhaust with which cooperate by coincidence of the lights of the two rotors B angular overlap, said rotors being subjected to rotational drive means synchronized with the motor and capable of angularly phase shifting them to obtain variable angles of opening valves. In addition, the invention also advantageously protects against variable control of the valve lift.

To this end, it is then characterized in that it is presumed in the internal rotor, in the axial interval of the lights intended to be connected to the two sides of the jack, a movable piston for discharging the hydraulic fluid towards the vdrin, and a variable end-of-stroke stop for this piston being provided in the direction limiting the quantity of fluid discharged onto the jack for opening the valve, in order to control the amplitude of the lift
Two embodiments of the invention are also described below, by way of example, and with reference to the accompanying drawing, in which: - - Figure 9 is an axial sectional view of a control
valve hydraulics by single-acting cylinder - Figure 2 is a partial view similar to Figure 1
illustrating another distribution status of the order
hydraulic 3 - Figure 3 is an axial view of a control
valve hydraulics by double-acting cylinder, including
a valve lift check associated with the check
distribution angle 3 - Figure 4 is a partial view similar to Figure 32
illustrating another distribution status of the order
hydraulic 3 - Figure 5 is a schematic view of a communication device
demand for variation of the distribution g
- Figure 6 is a cross-sectional view of a form of
realization of a hydraulic distributor body for the
control of four valves.

The valve control shown in FIG. 1 comprises a single-acting hydraulic cylinder 1, the piston rod 2 of which emerges from the cylinder is intended to act as the valve plunger to be controlled, not shown, the piston 3 of the cylinder being normally recalled by a spring 4 in the non-actuation position of the valve. This cylinder 1 is supplied by means of a hydraulic distributor comprising a body 5 in which two cylindrical rotors 6 and 7 are rotatably mounted, forming mobile distribution members and intended to be driven at half speed of the engine, but with a possibility of angular phase shift relative to each other.

 # this effect, the rotors 6, 7 are driven by an epicyclic mechanism comprising a planet carrier 8 with two satellites 9 on the rotor 6, and a satellite loss 10 with two satellites 11 on the rotor 7, the respective satellites of which are axially offset and about a right angle, while engaging with a crown 12 with corresponding internal teeth and external teeth engaged with a toothed drive belt 13 passing over a drive pulley not shown, which is integral in rotation of the engine crankshaft.

The satellites 11 linked to the rotor 7 are engaged with a central planetary gear 14 secured to a tubular axis 15 which is fixed, by means of a flange 16 with a flange, to a mounting support 17 of the control, also connected to the body 5 of the hydraulic distributor. On the axis 15 is rotatably mounted, with the interposition of a bearing 18, a support flange 19 of the ring gear 12 of the mechanism.

The satellites 9 linked to the rotor 6 are engaged with a central planetary gear 20 secured to a tubular axis 21 mounted rotating in the axis 15 and passing through the support 17. This axis 2t is secured at its free end to a plug 22 provided with 'A lever 22a for setting in variable angular position of the sun gear 20 relative to the fixed sun gear 14, which thus makes it possible to introduce a variable angular phase shift between the rotors 6 and 7, moreover driven at the same speed and in the same sense of rotation. We will see later how the angular position of the lever 22a can be regulated, for example.

The rotor 7 is provided with an end plug 7a delimiting an internal chamber of the rotors with the body 5 of the distributor.

There is shown in FIG. I a hydraulic distribution phase corresponding to the lifting of the valve, for which, facing an inlet duct 23 for pressurized oil in the body 5, to which 1 source of pressurized oil is connected by a pipe 24, two superimposed lights 5, 26 pass from rotors 6 and 7, while other lights 27 and 28 also pass superimposed and facing a chamber 29 of the distributor body , of width equivalent to the diameter of the conduit 23, and which is connected by the pipe 30 to the jack 1. A distribution of oil under pressure to the jack is thus carried out according to the arrows indicated to cause the valve to be lifted by action of the piston rod 2.

FIG. 2 illustrates a hydraulic distribution phase by the rotors 6, 7 corresponding to the closing of the valve and for which, opposite an exhaust pipe 31 of pressurized oil outside the body 5, to which is connected a pipe 32 returning to the reservoir, comes to superimpose two lights 33, 34 of the rotors 6, 7, while two other 35, 36 of the latter also come to pass in superposition and facing the chamber 29 of the body of the distributor stopper, so that the cylinder 1 is put to exhaust according to the arrows indicated, under the action of its spring 4, while the piston rod 2 lets the valve return to the closed position.

It is easily understood that these two phases can be spaced at an angle suitable for a desired opening angle of the valve, by the angular spacing given to the lights considered of the rotors 6, 7 but, moreover, the angular phase shift of these the latter allows the valve opening angle to be varied by giving the twisted ports a variable overlap alternating with the inlet and outlet of the oil under pressure
Thus, assuming that the choice is made of rotor 6 to control the valve lift and of rotor 7 to govern closure, the lights of these rotors have the following shapes: - lights 25 and 27 of rotor 6 are circular while
the cooperating lights 26 and 28 of the rotor 7 extend sai
before a circular are a function of the angular phase shift
sought above; the lights 34 and 36 of the rotor 7 are circular while
the cooperating lights 33 and 35 of the rotor 6 s1 extend further
vant a circular arc function of the pre angular phase shift
cited.

Thus, the angular phase shift of the rotors makes it possible to open or close symmetrically the distribution angle for which the lights coincide with the duct 23, the chamber 29 or the duct 31 of the distributor, that is to say to open or similarly close the opening angle of the controlled valve0
Figures 3 and 4 relate to an embodiment of valve control by double-acting cylinder, further comprising a control of the valve lift
The double-acting cylinder B 37 has a piston rod 38 intended to hold the valve plunger link k not shown. It includes a piston return spring 39 in the non-actuation position of the valve, fulfilling the function of Valve position "coding", which is normally fitted by its own springs This cylinder is supplied by means of a hydraulic distributor in the body 40 of which two cylindrical rotors 41, 42 are rotatably mounted, forming mobile distribution members and which are driven like the rotors 6 and 7, at half the speed of the motor and with the possibility of angular phase shift relative to each other, by a mechanism similar to that of FIG. 1, the equivalent elements of which are designated by the same reference figures.

The internal rotor 42 is provided with an end plug 43 which forms an annular chamber 44 in the rotor and serves as a guide b a rod 45 serving as an adjustable stop k a piston 46 mounted to slide and free in the rotor where it delimits a chamber 47 with the internal face of the plug 43 and a chamber 48 relative to the internal face of another end plug 49 of the rotor, which also forms therein an annular chamber 50.

 The adjustable stop rod 45 extends out of the plug 22 which it passes through by sliding, and it will be seen below how its position can for example be regulated.

A body 51 of the pressurized oil inlet is connected to the body 40 of the hydraulic distributor, which feeds a chamber 52 having two spaced outlet conduits 53, 54, with which the ports 55, 56 of the two rotors cooperate respectively (see fig. 3) and 57-58 (see fig. 4).

Two pipes 59-60 connect the two chambers of the cylinder 37b two chambers 61, 62 of the body 40, with which cooperate, on the one hand, of the lights 632 64 of the two rotors (see fig. 3) and 65, 66 (see fig. 4), and on the other hand lights 67, 68 of the two rotors (see fig. 3) and 69, 70 (see fig. 4).

Two exhaust pipes 71, 72 are connected to conduits 73, 74 with which the lights 75, 76 of the two rotors (see fig. 3) and 77, 78 cooperate respectively (see fig. 4).

FIG. 3 shows a hydraulic distribution phase corresponding to the lifting of the valve, for which a distribution of oil under pressure takes place according to the arrows indicated, starting from the pipe 51, through the chamber 52, the conduit 53 and the lights 55, 56, in the chamber 48, where the pressurized oil pushes the piston 46 which in turn pushes the oil from the chamber 47 through the lights 63, 64, the chamber 61 and the pipe 59 , in the cylinder chamber 37 where the pressurized oil actuates the piston and its push rod 38 in the direction of opening of the valve. At the same time, the cylinder chamber containing the spring 39 is se exhaust through the silk of the pipe 60, of the chamber 62S of the lights 67, 68, of the chamber 50, of the lights 769 75 and of the conduit 73 for connection of the exhaust pipe 71.

FIG. 4 shows a hydrau liqu distribution phase. corresponding to the closing of the valve, for which a distribution of oil under pressure takes place according to the arrows indicated, starting from the pipe 51, through the chamber 52, the conduit 54 and the ports 57, 58, in the chamber 47, where the pressurized oil pushes the piston 46 which in turn delivers the oil from the chamber 48 through the ports 70, 69, the chamber 62 and the pipe 60, into the chamber of the jack 37 containing the spring 39, so that the push rod 38 authorizes the. closing the valve. At the same time, the other chamber of the jack is exhausted via the pipe 59, the chamber 6t, the lights 659 66, the chamber 44, the lights 78, 77 and the connecting conduit 74 of the exhaust pipe 72.

In order to be able to vary the opening angle of the valve by angular phase shift of the rotors and the cooperating lights, as already explained with regard to FIGS. T and 2, and on the assumption that 1'4n chooses the rotor 41 to control the lifting of the valve and of the rotor 42 to govern the closing, the lights of these rotors have the following forms X - the lights 55, 64, 67 and 75 of the rotor 41 are circular
while the cooperating lights 56, 63, 68 and 76 of the
rotor 42 extend in a circular arc depending on the
angular phase shift sought 3 - the lights 58, 70, 66 and 78 of the rotor 42 are circular
while the cooperating lights 57, 69, 65 and 77 extend
tooth following a circular arc function of the angu phase shift
sought area.

It will be noted that, in addition, in this embodiment, the arrangement of the adjustable stop rod 45 makes it possible to control the volume of oil discharged by the piston 46 into the cylinder 37 when the valve is opened, that is that is to say to control the amplitude of the valve lift,
As well in the object of Figures 1 and 2 as that object of Figures 3 and 4, it will be noted that the distribution lights of the -rotors governing the opening and closing of a valve extend over less than 180 taking into account that the rotors rotate at half-speed of the engine, and that each rotor can therefore easily be provided on the same circumference with distribution lights to control two valves, the intake ducts and distribution chambers of the distributor body specific to each of the valves to be offset in eoesEquenceO
In the case of FIGS. 1 and 2, the distributor body and the rotors can therefore be prelenged to control two valves as many times as necessary, it being understood that it is sufficient to separate each of the distributions for two valves of the neighbor by a fixed partition attached to the internal rotor 7.

In the case of FIGS. 3 and 4, taking into account the valve lift control using the adjustable stop rod 45, the device described applicable to two valves, can be extended to control four valves with rotors 41, 42 extended, by doubling the distribution symmetrically with respect to the plane of the fend of the plug 49, so as to have another adjustable stop rod such as 45 B at the other end of the distributor thus extended.

FIG. 6 illustrates a form of angular distribution of the intake ducts and distribution chambers on a distributor body for the control of four valves, applicable as well to the cases of FIGS. 1 and 2 as 3 and 4, but whose figures of reference relate to b by way of example in the case of FIGS. 3 and 4, and in which the letters E and S designated by the index t to 4 have designated the inputs and outputs of the body 40 corresponding to the four valves considered.

Although a coarse mode of adjusting the position of the lever 22a by which the variation in the valve opening angle is introduced may consist of a simple direct mechanical connection with the accelerator pedal of the vehicle, so that the the opening angle is all the greater as the engine load is higher, one can also provide a more refined parametric control of the distribution as illustrated in example in FIG. 5. The lever 22a is then connected by via a hinge pin 79 to the piston rod 80 of a single-acting cylinder 81 supplied by a line 82 under the pressure of the engine oil pump not shown, and having an exhaust line 83 b variable leakage controlled by a solenoid valve 84. This leakage is regulated by the opening duty cycle of the solenoid valve 84, controlled by an electronic pulse generator 85, such as a voltage-frequency converter, receiving parameters under for me of electrical voltages representative of the engine load (potentiometer 86 linked to the accelerator pedal 87) and emanating from sensors of engine speed #, water temperature ti, oil t2, ambient air t3 and the speed V of the vehicle
The adjustable stop rod 45 can be controlled in a similar, coarse or refined manner, to that of the lever 22a.

Of course, many variants can be imagined while remaining within the scope of the invention.

Claims (3)

1. Control of internal combustion engine valves, characterized in that it comprises9 for each intake or exhaust valve, a hydraulic actuator for the valve, and for all hydraulic actuators intake or exhaust valves, a distributor comprising two concentric cylindrical rotors rotatably mounted in a body comprising, for supplying the cylinder of each valve, intake ports for pressurized hydraulic fluid and exhaust with which cooperate by coincidence of the lights of the two rotors with angular overlap, said rotors being subjected to drive means in rotation synchronized with the motor and capable of angularly shifting them to obtain variable angles of opening of the valves. 2. Valve control according to claim 1, characterized in that each actuating cylinder is double acting and that it is provided in the internal rotor, in the axial interval of the lights intended to be connected to the two sides of the cylinder , a movable piston for discharging the hydraulic fluid towards the jack, a variable end-of-stroke stop for this piston being provided in the direction limiting the quantity of fluid discharged onto the jack for opening the valve, in order to control it the amplitude of the lifting. 30 Valve control according to one of the preceding claims, characterized in that the rotor apertures have an alternating angular overlap for the admission and the escape of hydraulic fluid for controlling the actuator. 4. Valve control according to one of the preceding claims, characterized in that the said rotational drive means comprise a planetary gear train with two planet carriers respectively connected to the two rotors and cooperating with two similar elements of the train, one of which is fixed and the another angularly phase-shiftable with respect to it. 5. Valve control according to claim 4, characterized in that the fixed and phase-shifting elements are two planetary and that the element forming the crown of the train constitutes a toothed pulley driven by the rotator