FR2673682A1 - Hydraulic valve gear intended to improve the performance of internal combustion engines - Google Patents

Abstract

Device making it possible to improve the performance of internal combustion engines by variation and monitoring of the volumetric compression ratio before explosion. It comprises hydraulic valve gear including variable chambers (1) in which two-part pistons move, controlled by a metering pump/lock (2), with a centraliser plus a non-return valve and anti-pinking probe connected to a microprocessor. The assembly is actuated by the cam (9) located at the end of the camshaft of the engine. The invention may be used for increasing the efficiency of internal combustion engines whilst decreasing the fuel consumption and pollution by complete combustion of the gases.

Description

Hydraulic distributor intended to increase the performance of internal combustion engines.

 The present invention relates to means making it possible to vary in operation the compression compression ratio of an internal combustion engine.

 It is known that the thermodynamic efficiency of gasoline engines is higher the higher their volumetric compression ratio.

 With the engine running at full load, the value of this volumetric ratio is limited by the octane number of the fuels used. Any increase in this limit ratio leading to serious disturbances in the operation of the engine, in particular due to the appearance of the rattling phenomenon.

 This is why it has already been proposed by several inventions to arrange internal combustion engines so as to be able to vary their compression compression ratio during operation.

 According to a first known device of this kind, the piston of the engine has an external part capable, thanks to hydraulic means, of moving axially by a limited amount relative to an internal part linked to the connecting rod.

The supply of pressurized hydraulic fluid is via the connecting rod and the crankshaft, which leads to very significant complications.

 According to another known device of this kind, another design consists in supplying a variable chamber placed at the end of each cylinder and supplied with engine oil. This supply being regulated by the vacuum which exists in the intake manifold, this invention has the disadvantage of not guaranteeing the pressure accurately before explosion. The variation in engine speed resulting in pressure drops and very large displacements of the variable chambers incompatible with correct operation.

 According to another known device of this kind, another design relates to a device for increasing the compression ratio by means of an auxiliary piston and cylinder. The calibrated and adjustable spring piston allows a slight increase in the operating pressure very close to the detonation pressure. This device can only be used at low speeds.

Over the few years covered by said research, we noted the following patents: - NO 2397530 PEUGEOT and CITROEN - NO 2438162 RAYNE - NO 2440472 RAYNE - NO 2446383 ROTHAS
The device which is the subject of the present invention makes it possible to avoid these drawbacks.

 Indeed, the system proposed by the present invention calls upon elements which contribute to controlling with precision and at all speeds the pressure before explosion.

Therefore we will have as a result: - A higher efficiency - A higher torque even at low revs - A complete combustion of gases hence a reduction in pollution - A reduction in consumption
The device according to the invention is composed of a hydraulic distributor intended to increase the performance of internal combustion engines. What is known in the current art is the possibility of varying the volume of the compression chamber without obtaining exactly the correct operating parameters at all the revolutions of an internal combustion engine.

 The system proposed by this invention consists in varying in operation the compression compression ratio of a 2 or 4 stroke internal combustion engine.

 The manufacturer defines this compression rate to obtain the best performance, but it turns out that variations in speed cause imperfect filling of the chambers, hence a rate lower than the prescribed rate.

 The system uses assemblies which allow all rotational speeds to maintain the compression ratio initially calculated and to avoid damaging rattling mechanically.

 The variation of the volumetric ratio is given by a dosing-lock pump which injects into a variable chamber a small quantity of hydraulic liquid and the compression rate is permanently controlled by a valve calibrated at the rate indicated before the explosion. A lock ensures after this control thanks to a cam, a non-return of the hydraulic fluid.

 The device which is the subject of the invention comprises variable chambers in two specific cases.

 10 / On an air-cooled engine with two opposite cylinders.

 The chamber 1 at the end of each cylinder ensuring the variation in volume before explosion is secured with a screwed assembly according to FIG. 1 of plate 1/7.

 20 / On a water-cooled engine.

 The variable chamber 1 is located directly in the cylinder head according to Figure 2 of plate 1/7.

 The accompanying drawing plates illustrate, by way of example, an embodiment of the device according to the present invention.

 For a better understanding of the proposed system, the explanation is made from an engine with two opposite cylinders flat and air-cooled. This system is non-limiting and can be carried out on an engine with four or more cylinders, or less, according to the adaptation made in FIG. 2 of plate 1/7.

 According to FIG. 3 of plate 2/7, the variable chamber 1 placed at the end of each cylinder receives, according to a well defined cycle, the hydraulic fluid by a bolt metering pump assembly 2, and a centralizer 3 conducts the hydraulic fluid under pressure so as to ensure the final working pressure at the pressure control 4.

 The latter system 4 is controlled by a rotary electromagnet 5 which obeys the start-up and its use by a microprocess 6 and a knock sensor 7 placed on the cylinder.

 The hydraulic fluid which is in excess at the pressure control 4 is sent to the reservoir 8 which ensures its filtering and cooling.

 It is understood that the cycle described by this 2/7 plate conforms to the intake, expansion compression and exhaust diagram and that the permanent regulation of this system is ensured by the cam 9 precisely calibrated at the end of the camshaft of the engine considered.

 According to the drawings in plate 3/7, the variable chamber 1 is constituted by a reamed cylinder provided with cooling fins. In the bore of the latter is located in the front part according to FIG. 4, a jacket 10 threaded in front for its adaptation in the cylinder head of the engine with a copper gasket 29 and a rear thread for its fixing on the chamber 1.

 A spacer ll along the section bb 'shown in Figure 9 provides lubrication of the jacket 10 and venting through two threads formed perpendicularly in the variable jacket 1, one for the arrival of lubricating oil and the other the return.

 A rear jacket 12 comes to fit in the bore of the variable chimney l, the whole closed by a bottom 13 which ensures by its assembly with screws, the perfect sealing of the whole.

 Inside this cylinder thus formed by the liners 10 - 12, a telescopic piston circulates having at the front part 14 the sealing segments 15 with an oil scraper segment. The piston 14 is connected to a rear piston 17 by an axis 18 and a pin 19.

 This telescopic system provides the piston 14 with a longitudinal displacement relative to the piston 17 and ensuring by the axis 18 a defined displacement equal to D in FIG. 6.

 The lubrication and the evacuation of the residual gas dishes from the explosion are done by the dishes according to section aa 'shown in FIG. 8 and the evacuation holes 16.

 A spring 20 ensures a suitable operation for taking off the segments 15. The spacer ll machined in two parts for mounting receives the support of a spacer 21 and two belleville washers 22.

 This arrangement avoids the piston 17 from being blocked permanently on the spacer ll when the piston 17 comes into abutment. A seal 23 seals the hydraulic chamber 24. At the center of the bottom 13 there is an outlet which will control the hydraulic chamber 24.

 The hydraulic fluid arrives via the orifice 26 and the arrangement 27 is intended to receive a bleed screw adapted to the hydraulic system. A damper seal 28 is interposed between the faces of the front piston 10 and rear piston 17.

 Figure 5 shows the telescopic system.

 Figure 6 clearly defines the process used in this system. The relative displacement D equal to v the final volume of variation is therefore equal to V-v.

 It is understood that the mounting of a variable jacket must define with the engine piston, the assemblies being mounted and the piston 17 placed as a rear stop, the volume necessary to obtain the compression ratio established by the manufacturer.

 The front pistons 14 having the same diameter as the rear piston 17, the pressure per cm 2 is equivalent.

Figure 7 uses the same process but with a monobloc piston, in this case it can be used for the cylinder with an appropriate coating as well as for the piston of high resistance namely ceramic or tungsten carbide, etc.
Following the drawings of plate 4/7, we have a detailed description of the mounting of the metering-lock pump 2.

The latter, as shown in Figure 10, consists of a plate in which are machined two bores 30 placed in alignment and which each receive a jacket 31 retained by a circlip 32. In each jacket 31 moves a piston 33 biased by a spring 34. In the plate of the metering-lock pump 2 is located a bore perpendicular to the axis of the bores 30 and intended to receive the cam 9. This cam 9 is held by a pin 35, the latter being held by bearings 36. The axis 35 ends with a driver 37 provided with a drive pin 38. All this mobile assembly is connected at the end of the engine camshaft and rotates at the same speed. The process is therefore as follows, the housing 39 containing the cam shaft support assembly 35 is fixed and supports the metering pump-lock plate 2.

 The cam 9 in its rotation will act successively on each piston 33 and will determine a longitudinal displacement and the spring 34 will put pressure on the piston 33 to ensure permanent contact on the cam 9. Thus, the jacket 31 and piston 33 assembly will determine a chamber 40 of variable volume. Through a conduit 41 the hydraulic fluid arrives through holes 42 machined in the jacket 31 in the variable chamber 40. When the hydraulic fluid is compressed in the variable chamber 40, it will exit through the channel 42 provided with an anti-valve return 43. If the pressure is too high, a safety channel 44 is closed by a ball 45 under the action of a calibrated spring 46 which will act accordingly and the liquid will return via the annular chamber 46 in the conduit 41.

 The piston 33 and the jacket 31 have, along the section bb 'shown in FIG. 12, an oblong duct which will be 47 for the jacket 31 and 48 for the piston 33. When the piston 31 moves, the ducts 47 and 48 have two positions, l 'one when opening, the other when closing.

 For a correct assembly, as indicated in FIG. 11, a washer 49 positions the liners 31 and the pistons 33 according to the section cc ′ represented in FIG. 13.

 In the section aa'represented in FIG. 14, an appropriately shaped adjustment cam 50 allows an on position of the metering-lock pump 2, an intermediate position for adjustment and bleeding of the hydraulic fluid and the last position for neutralizing the device. dosing-lock pump 2.

The cam 9 having no action on the pistons 33.

 A centralizer 3 is fixed on the metering-lock pump 2 to permanently channel the hydraulic fluid which passes through the oblong channels 47 and 48.

 FIG. 15 represents the section dd which is found in FIG. 10.

 FIG. 16 represents the section ee which is found in FIG. 11.

 Following the drawings in Plate 5/7, we have a diagram in each figure considered to explain the operation of the metering-lock pump 2.

 Figure 17: The cam 9 secured to its axis 35 rotates according to the arrow of rotation. It rests on the piston 33 which receives the action of the spring 34. The variable chamber 40 is filled with hydraulic fluid through the conduit 41 and the annular chamber 46. The engine piston is in bottom dead center.

 Figure 18: The cam 9 in its rotation pushes the piston 33, the compression begins in the variable chamber 40 and the oblong duct 48 of the piston 33 discovers the oblong duct 47 of the liner 31 and the communication is established.

 The engine piston begins to compress.

 Figure 19: The cam 9 has pushed the piston 33 and the variable chamber 40 is closed. Communication is always established with the oblong conduits 47-48.

 The engine piston continues to compress.

Figure 20: At this moment, the cam 9 completely opens the communication in the oblong conduits 47 and 48 and it is the maximum displacement of the piston 33. In this displacement the piston 33 determines a compressed volume of hydraulic liquid equal to the surface of the piston 33 multiplied by its displacement
X.

 The volume of hydraulic fluid compressed in the variable chamber 40 raises the non-return valve 43 through the conduit 42 and the liquid will leave in the variable chamber 1 by the inlet 26 and if the rear piston 17 of this said variable chamber 1 is in abutment on the spacer 11 via the spacer 21 and the belleville washers 22, the pressure becoming too great and damaging in the mechanical connections by the conduit 44 -figure 20- and the ball 45, safety will be made and the surplus hydraulic fluid will return to annular chamber 46.

 Compression of the engine piston continues.

 Figure 21: The cam has completed its role in the displacement of the piston 33 and at this precise moment the conduits 47 and 48 are closed, hence the name lock. In fact, in the variable chamber 1 there prevails an explosion pressure equivalent to that which the engine piston undergoes, the hydraulic fluid from the rear chamber 24 of the variable chamber 1 cannot escape retained by the non-return valve 43 and the lock established by the piston 33 and the jacket 31 by means of the oblong conduits 47 and 48.

 At this precise moment the engine piston is in top dead center and the trigger begins.

Figure 22 shows the section gg 'found in Figure 21
It should be noted that the locking of the oblong conduits 47-48 is done on a motor piston in final compression and that the hydraulic fluid from the variable chamber will arrive on a motor piston in the exhaust end phase.

 This obviously relates to the adjustment of the engine and its design for example, in the order of ignition 1-3-4-2 or 12-4-3.

 According to the drawings on plate 6/7, it is crucial to explain the essential role of the pressure control assembly 4. This, as its name suggests, will prevail the compression ratio before explosion established by the manufacturer with accuracy it will serve as a balance chimney. Indeed, in an internal combustion engine we seek to obtain the best filling of the cylinders to increase the final efficiency.

From where expensive and complex devices, namely turbo, multi valves. It is necessary to extend the expansion of the gases to the maximum and above all to obtain the highest explosion temperature and all its advantages: perfectly burnt gases, reduction in pollution, maximum torque at low speeds.

 The ideal engine should be established for example with a displacement of 1000 cm3 and a rebound of 2000 cm3 to obtain a complete rebound this is incompatible with the crank rod system where calories lost to the exhaust.

 With the pressure control system 4 the gas intake in the engine cylinder will be used to the maximum.

 As shown in Figure 23, the pressure control assembly consists of a body 4 which is arranged with a conduit 51 connected by piping to the centralizer 3. At the other end is arranged a calibrated valve 52 by a spring 53 under the action of a tip 54 and a screw 55 for adjustment. This first pressure control element is adjusted with the compression pressure before explosion, for example for the engine considered 11 kg per cm2.

 A conduit 56 connects a socket 57 arranged in a fixed housing 58. Following the section cc 'shown in FIG. 27 we see that the socket 57 has holes 59 on its periphery. On the fixed housing 58 holes 60 are arranged. We note that If we rotate the socket 57 (cc cut) by an amplitude calculated thanks to the stop pin 64 we have the possibility of making the holes of the socket 57 coincide with those of the fixed housing 58.

 If we make them coincide we realize that we emerge in a low pressure conduit 61 which is regularized by a set 62 similar to that of high pressure constituted by the elements 52, 53, 54, 55. This pressure must be half that high pressure to serve as a regulator, when the engine is started, stopped and abrupt changes in engine speed.

 As shown in FIG. 24, a pressure tap 63 is used for adjusting the pressure control assembly 4.

 FIGS. 25 and 26 respectively represent the sections aa and bb which are found in FIG. 23.

 All the adjustment parameters are regulated by the microprocessor 6 which gives the necessary pulses to the rotary electromagnet 5.

 According to a variant of the invention, in plate 7/7 we see that for the explanations given previously we have taken as an example a two-cylinder engine.

 According to Figure 28, an embodiment is established for a four cylinder and we see the arrangement of the dosing pump-lock assembly 2, with all the details concerning the assembly, it is obvious that the other constituent elements remain unchanged according to plate 2 / 7.

 The device can also be mounted on a multi-cylinder or single-cylinder engine.

Claims (7)

10 / Device making it possible to increase the performance of internal combustion engines by varying and controlling the compression compression ratio at all speeds before explosion, characterized by a hydraulic distributor with reservoir of hydraulic liquid for cooling, comprising variable chambers (1) in which pistons (14 + 17) move in two partial, controlled by a metering-lock pump (2), with centralizer (3) plus non-return valve (43) and anti-knock probe (7) connected to a microprocessor (6). 20 / Device according to claim 1, characterized by a variable chamber (1) in which the piston is in two parts, namely the front piston (14) connected to the rear piston (17) by a pin (18) and a pin ( 19) and biased between them by a spring (20). Which ensures relative displacement D avoiding sticking in operation of the segments (15) and normal lubrication in use. 30 / Device according to claim 1, characterized by a metering-lock pump (2) the main thing of which is to control a volume of hydraulic liquid to be injected into the variable chamber (1) in the space provided (24) for this purpose . The process is obtained by a piston (33) biased by a spring (34) under the action of the cam (9) in the variable chamber (40) and which determines on the board 5/7 figure 20 the volume generated by the surface of the piston (33) and its displacement X. 40 / Device according to claim 1, characterized by a metering-lock pump (2) to ensure in operation a pressure safety in the rear chamber (24) of the variable chamber (1) via a channel safety (44) of a ball (45) and an annular chamber (46). All this to avoid blocking of the rear piston (17) on the spacer (21) of the variable chamber (1) 50 / Device according to claim 1, characterized by a dosing-lock pump (2) which ensures a pressure determined with accuracy in the oblong duct (47) of the jacket (31) and the oblong duct (48) of the piston (33). The relative movement of the piston (33) relative to the fixed jacket (31) determines the opening or closing of the oblong conduits (47 + 48), hence the term lock.  6 / Device according to claim I, characterized by the metering-lock pump (2). The lock serving its purpose between the oblong conduits (47 + 48) a non-return valve (43) ensures complete closure of the channel (42). Hence a complete locking of the dosing pump-lock device (2) ensuring the complete closing of the rear chamber (24) of the variable chamber (1). 70 / A device according to claim 1, characterized by the metering-lock pump (2) which has an appropriately shaped adjustment cam (50) which allows an on position, an adjustment and bleeding position of the hydraulic circuit, a neutral position for setting off the operation of the dosing pump-lock device (2). 80 / Device according to claim 1, characterized by the metering-lock pump (2) thanks to a centralizer (3) connected to a pressure control assembly (4) controlled by a rotary electromagnet (5) making it possible to guarantee with accuracy of the pressure before explosion per cm2 on the engine in question, this being equal to the pressure per cm2 prevailing in the rear chamber (24) of the variable chamber (1). 90 / Apparatus according to claim 1, car26736623 by a knock sensor (7) connected to a microprocessor (6) which ensures the operating parameters of the engine, namely starting, sudden changes in rotation speed and l '' engine stop with time delay. 100 / Device according to claim 1, characterized in that the metering-lock pump device (2) with its annexes can be used on two-stroke, four-stroke single-cylinder, two-cylinder or multi-cylinder engines according to FIG. 28 of the board 7/7, and to ensure operation at all revolutions a compression ratio before explosion with accuracy and precision. Thus ensuring efficient engine torque, higher efficiency, much better expansion, complete combustion of gases and reduced pollution.