MXPA00002460A - Internal combustion engines - Google Patents

Abstract

An internal combustion engine includes one or more pistons (4), each of which is mounted to reciprocate in a respective cylinder (2) and is pivotally connected to a connecting rod (6) which is connected to a respective crank (10) on a crankshaft (7). The connecting rod (6) is pivotally connected to one end (11) of an elongate link (14) which is pivotally connected to an associated crank (10) at a point intermediate its ends and whose other end constitutes a rod (18) which is restrained by a mounting (20, 26) such that it may pivot about a pivotal axis (21) parallel to the axis (8) of the crankshaft (7). The mounting includes a first movable mounting member (20) connected to a second movable mounting member (26) to be pivotable with respect thereto about the pivotal axis (21). The first movable mounting (20) is connected to the rod (18) by a connection which permits only relative sliding movement in the direction of the rod (8). Actuating means (30, 32) is connected to the mounting and is arranged to move the mounting selectively in a first direction perpendicular to the axis (8) of the crankshaft (7) and in a second direction perpendicular thereto.

Description

INTERNAL COMBUSTION ENGINES. DESCRIPTION OF THE INVENTION The present invention relates to internal combustion engines of the reciprocating piston type and is related to such engines, which include one or more pistons, each of which is mounted to move alternatively in a respective cylinder. and is pivotably connected to a connecting rod which is in turn connected to a respective crank on a crankshaft, the connecting rod is pivotably connected to one end of an elongated connecting member, which is connected in pivotable form, in turn to a crank associated at an intermediate point of its ends and whose other end constitutes a rod, which is held by a mount such that it can rotate near the parallel axis of the pivot towards the axis of the crankshaft. The invention is also in a particular form, although not exclusively, related to engines of the general type described in EP-A-0591153. The previous document describes an engine in which, or each piston, is the cause to move over at least part of the cycle at a speed, which is such that the graph of its displacement versus time is different from -part of the sinusoidal shape, which is inherently produced in REF: 32867 conventional motors in which each piston is connected to a respective crank on a crankshaft by a respective connecting rod. Such attempts in a conventional engine are made to equal the combustion of the air / fuel mixture with the movement of the piston, but the fundamental philosophy of the construction of the previous document is that the combustion is allowed to continue in an optimal way and that the piston be the cause to move in a way, in which, "follow" the combustion and refer to the nature and progress of the combustion process. More specifically, the above document describes an engine, in which the piston is the cause for slowing down and thus moving more slowly than in a conventional engine, at or around the point in the cycle in which the combustion of the air mixture / fuel occurs and then accelerate again before reaching the top dead center (TDC) position. This is based on the recognition that in a conventional engine the piston is moving at substantially its maximum speed at a point at which combustion occurs and the compression ratio alternates at substantially its maximum speed and thus impedes the velocity ^ of propagation of. the front flame through the air / fuel mixture and thus damage the nature and totality of the combustion process. However, by reducing the speed of the piston near the point of combustion, it means that the rate of increase in the pressure of the air / fuel mixture at the time the propagation of the frontal flame begins is substantially less than what is usual , which results in the front flame propagating through the air / fuel mixture much more quickly than usual. The previous document also describes that the piston is the cause to reach its maximum acceleration and its maximum speed between 0 and 40 ° after the position of top dead center (TDC), instead of 90 ° after the position of top dead center (TDC), as in a conventional engine and later to move more slowly than in a conventional engine in the last part of its career or work route, before reaching the position of bottom dead center (BDC). This results in a reduction of the exhaust gas temperature and therefore in a reduction of Nox emissions and reduce the erosion of the valves and exhaust ports. Extensive tests have been conducted on engines built according to EP-A-0591153 and these have shown that the engine, in effect, has a substantial increase in efficiency compared to conventional engines and also dramatically reduces emissions of unburned gases such as CO and Nox hydrocarbons. Indeed, these tests have shown that the combustion process in the motors according to the previous document in a continuous way, which, is fundamentally different to what is in the conventional engines, as evidenced by the fact that, for For example, the speed of pressure that increases in the cylinder is about 6.5 bar per degree of rotation of shaft or shaft efficiency, compared to about 2.5 bar in a conventional engine and that combustion is completed within about 22 ° of rotation of the performance of the rear axle to the top dead center position (TDC), compared to around 60 ° in a conventional engine. However, the engine described in the above document incorporates profile cams that cooperate with the pistons and not a conventional crankshaft and while such cams are fully functional and technically satisfactory, it would be preferable for the engine to incorporate a conventional type crankshaft in a general manner because The facilities for the mass production of crankshafts are already available and the technology for the manufacture of crankshaft-type engines is better known and proven than the technology for cam-type engines. Accordingly, it is the object of the present invention to produce an internal combustion engine of the reciprocating piston type, in which the time displacement graph of the or each piston is different from the sinusoidal shape of the piston type engines. conventional crankshaft, for example, in a manner similar to that described in EP-A-0591153, and can also be altered, when the engine is in operation, without including a crankshaft of conventional type in general form. An engine of the specific type to which the invention relates is described in US-A-2506088. In the engine described in this prior document the other end of the elongated joint member, for example, the farthest end of the piston, is connected in rotated form to one end of a short arm whose other end is mounted on a fixed pivot for out there spin. While the piston has an alternative movement and the associated handle rotates about the axis of the crankshaft, the other end of the connecting member is forced by the short arm to rotate csp around the fixed pivot at a speed equal to that of the crankshaft.

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The pattern of movement of the piston in this engine will be different from the true sine wave, but in a way that is predetermined and unalterable. However, in order to optimize the combustion of the air / fuel mixture, for the purpose of maximizing efficiency and minimizing emissions, it is desirable that means be provided to alter the movement pattern of the piston in dependence on speed, the load and other parameters.

Therefore, the GHB of the Ministry of Industry and Industry will not operate or grind it according to the teachings of the EP-A-05TU53, but in the case of the povippaito of the milling machine it is to the mill, prefis * rih1 emente autanáiao, in to send to the paranetres of rpición of noticing. I agree with the present iiwgrp? , a motor of aaitxjstdcn inLa of the referred type aitrericprente is < .ywv., * tfyi7pdr > However, the assembly inclines a primar plan of pcptage that is poputably collected at a second point of plane that is portable, but can be rotated with respect to them around the pivot axis, the fi rst physical plane that is rotated. ujfcj tdú to the rod for a reason that allows only the relative sliding lipstick in the direction of the rod, and the medium of the adiprce is a:? tFrt < Hrtr > to the perm, and is arrHj1rrr > To ptwr the assembly selectively in a first direction papa.Tin.1fir to the axis of the rt grima! and adaiós in a sagurda óáxe? aa transvasal.

Thus, in the motor of the present invention, the connecting rod is not directly connected in a pivotable manner to a respective crank but indirectly through one end of a connecting member which is connected in a pivotable manner. both to the crank and to the connecting rod. The other end of the joining member is thus mounted to be rotated together with a third pivot axis, which will be parallel to the other two, and to be movable in a linear fashion parallel to its length. The movement of the piston, in this way, will be different from the sinusoidal and can be varied at will by varying the space and the relative positions of the three pivot axes of the union member, which, in general, will not be placed in a single plane . This is, however, preferred, that the three pivot axes are thus positioned, that the movement of the piston is simulated closely, that the piston of the motor is described in EP-A-0591153, and in particular that the piston is the cause to move significantly more slowly around the point of combustion than in a conventional engine. The invention is applicable both to two-stroke engines as well as to four-stroke engines, of both types of spark ignition as well as diesel. It will be understood that the actuation means allows the third pivot axis, that is, to mark the axis around which the rod rotates with respect to the assembly, to be moved thereby forcing the piston movement to alternate. This may be desirable to allow the engine to operate optimally at different speeds and / or loads, and in fact may be varied to vary the sweep volume of the or each cylinder, and the compression ratio of the engine, as It will be discussed in more detail below. In the case that the engine is of four times, it would be desirable for the movement of the piston to differentiate between the compression and the exhaust time and perhaps still also between the induction and the working stroke or time. This can be accomplished in a variety of ways, for example, by causing the assembly to move in an alternating fashion linearly in synchrony with the associated piston. The actuating means may be used, not only to vary the manner in which the movement of the piston varies from the sinusoidal but may be used, at least in part, to produce the variation and thus be actuated during the course of the operation. Piston stroke, for example, at or around the combustion point to produce the desired loss of piston velocity at that point. It is also preferred ^ - that the elongated joint and the assembly are thus sized and arranged in such a way that, when the motor is in operation, the pivot axis near which the connecting rod rotates with respect to the elongated joint member and generally describes an oval or elliptical path, the major axis 5 of the ellipse generally extends in parallel to the cylinder axis. The first direction in which the assembly moves is preferably substantially parallel to the cylinder axis and the second direction is preferably substantially perpendicular to the axis of the cylinder. It is preferred that the actuating means comprises a first actuator, which is connected to the assembly and is arranged to move it in one of the two directions, and a second actuator, which is connected to the first actuator and is arranged to move it together with the assembly in the other of the two directions. The two actuators may be of several different known types but it is preferred that they be of hydraulic type. The actuators are preferably under the control of a control means which is selectively arranged to operate them. The control means will typically be the engine management system ^ - as is now supplied in the most modern engines s ^ g¡tg ^ ») automotive. The ability to move the assembly in any desired perpendicular direction to the crankshaft by means of two actuators allows the trajectory of movement of the piston to be varied at will and, in particular, to be varied according to the parameters of the piston. engine operation, to optimize the operation of the engine at all times. It is found that the assembly movement in the first direction, that is to say substantially parallel to the axis of the cylinder, results mainly in a position movement of the top dead center (TDC) of the piston and thus in a change in the compression ratio of the engine. Such movement also results, however, to a lesser extent, in a change in the career of the piston and sweep volume. It is found that the movement of the assembly in the second direction, i.e. substantially perpendicular to the axis of the cylinder, results primarily in the movement of the position of the bottom dead center (BOC) of the piston and so on. primarily in a change in the stroke, as well as in the volume of sweep of the piston. The present invention in this way opens the possibility of varying the compression ratio and the sweep volume of the engine, within the limits set by the geometry of the components, forcing the motor to equalize with -. * _? £ Í2J the operating parameters ^^ antiane. It is preferred that the engine includes a first detector arranged to produce a signal indicating that the machine has begun pounding or is about to begin, the control means is arranged to operate the actuating means, to move the assembly into the first direction to reduce the compression ratio and thus cause the knocking to stop. Such blow detectors are well known and comprise an acoustic or vibration detector located in or the cylinder block and allow the compression ratio of the motor to be reduced temporarily in the event that the knocking occurs, as well as to maximize its efficiency. It is also preferred that - the motor includes a second detector arranged to produce a signal indicative of a load on the motor, the control means is arranged to move the assembly in the first direction, to vary the compression ratio of the motor with a change load, for example decrease the compression ratio while the load is increased. Such load sensors are also known per se and can be exposed, for example, to the pressure in the engine intake manifold which grows while the load on the engine increases, or they can be mechanically attached to the shutter the motor. Movement of the assembly in the first direction will cause the compression ratio of the motor to change and will also cause the sweep volume and piston stroke to change slightly. This will alter the ignition regulation, which is not desirable and also can not be acceptable, by instance in racing engines, and will alter the sweep volume, both of these changes can be compensated if the control means is arranged to move the assembly in the second direction, therefore, the position of the bottom dead center (BDC) of the piston is altered to compensate for the changes caused by the movement of the assembly in the first direction. The optimum compression ratio of an engine varies with the load at which the subject and this optimum compression ratio increases while the load decreases. It is therefore possible with the aid of the present invention to ensure that the compression ratio is always at the optimum value but that the knocking of the motor does not occur. If so, for instance, the motor is operating at low speed and low load and the load is increased - *? Suddenly, there is an instantaneous tendency for the knocking or pre-ignition to occur. This can be counteracted by temporarily reducing the compression ratio if the assembly moves in the first direction and optionally compensates by moving it also in the second direction. As the motor speed increases, the control means is desirably programmed to also produce a progressive increase in the compression ratio towards the optimum value just below where the knocking would occur. Alternatively, the control means can be arranged to ensure that, if the load of the engine increases suddenly, the assembly moves in the second direction to effect a significant increase in the sweep volume by the piston. So if a sudden increase in power in the motor is required, the capacity in the motor can be increased, for example by 10%, so that an instantaneous and significant increase in output power results. The present invention can therefore be used to produce an increase in power similar in effect to that produced by a turbocharger or a supercharger and can be used for a conventional replacement, for high-cost superchargers or simply to "allow a motor of a capacity is altered to be of different capacity While the two parts of the joining member on the opposite sides of the crank, which is connected in a pivotable way, can be co-linear, it is found that it is preferable if they, in fact they tilt a little, for example, between 5 and 45. The increase in the speed of the propagation of the flame and the efficiency of combustion in the cylinder results in a very substantial increase in the efficiency of the engine, ie the output power per unit mass of fuel The efficiency is further increased by the fact that the connecting rod is inherently inclined towards the cylinder axis or when the piston is in the upper dead center (TDC) position. The maximum pressure inside the cylinder is produced in or around the top dead center (TDC) position, but in a conventional engine the connecting rod and the crank define a straight line parallel to the cylinder axis in the upper dead center position (TDC), which means that no torque is transmitted to the crankshaft in this position and that the high pressure inside the cylinder is "wasted" and results simply in the generation of additional heat. However, in the motor according to the present invention ^ the fact that - the connecting rod is inclined towards the axis of the cylinder in the position of puato B &; Higher torque (TDC) means that torque is transmitted to the crankshaft in the upper dead center (TDC) position and thus the high pressure prevailing in the upper dead center (TDC) position becomes a useful output pressure and It is not wasted. The features and additional details of the invention will be apparent from the following description of a specific embodiment which is given by way of example with reference to the accompanying schematic drawing, which is a sectional sectional view of part of a part of the invention. a multiple cylinder of a four-stroke engine, of which only one cylinder and the associated piston as well as the connecting mechanism of the piston are shown. In this mode, the engine has four cylinders. Although it could have more or less than this one, or even only a single cylinder, since only a single cylinder 2 is shown. The piston 4 is mounted alternately on the cylinder. The piston is pivotably connected to the shaft 5 in the usual manner towards the connecting rod 6. Beneath the or each of the extending cylinders 2 is a crankshaft 7, which is shown only schematically in the figure 1 and is mounted to rotate along the axis 8.

The crankshaft carries a respective crank or crank set 10 for each piston. The connecting rod 6, however, is not directly connected to the associated handle 10, but instead is pivotably connected to an axis 12 towards an end 11 of a respective elongated connection 14. The connection is also connected in a pivotable manner to an axis 16 at an intermediate p of its ends with the associated handle 10, with the interposition of an appropriate bearing 15. The other end 18 of the j 14, which is in the shape of a hollow bar , it is slidably received, longitudinally, in the assembly. The assembly includes a first movable mounting member 20, which is constituted by a ball or cylinder that provides a hole through which the bar 18 passes and which is slidably retained in that location. The movable mounting member 20 is retained in a hole or recess within a second movable mounting member 26 with the advantage of the clutch of its outer surface of circular section adjacent to the complementary complementary surfaces provided by the mounting member 26. The member 20 can thus be rotated with respect to the mounting member 26 adjacent to its center axis 21 but can not be moved linearly with respect to it.

The rod 18 can thus be moved only in rotation and parallel in a linear fashion to its length with respect to the mounting member 26. The assembly 20, 26 is connected to the two hydraulic actuators 30, 32 arranged to move linearly in two directions, which are mutually perpendicular to one another and are both perpendicular to the axis 8 of the crankshaft. The first actuator 30 carries the assembly and is arranged to move it substantially parallel to the axis of the cylinder and is returned by the second actuator 32 which is arranged to move it, and also, to the assembly substantially perpendicular to the axes of the actuator. crankshaft 7 and the other cylinder 2. The second actuator 32 is rigidly coupled to some fixed component 31 of the engine and is thus stationary. A piston 34 is rigidly connected to the second mounting member 26, and is accommodated in the cylinder 36 of the first actuator. Also connected to the second mounting member 26 is an elongated guide member 38, which is slidably received in the manner of a piston in the vent cavity 40 in the first actuator and ensures that the assembly moves smoothly and linearly. with respect to the first actuator. Similarly, rigidly constrained to the first actuator 30 is the piston 42, which is accommodated in the cylinder, 44 of the second actuator 32. Also connected to the second actuator is an elongated guide member 46, which is slidably received in the manner of a piston in the vent cavity 48 in the second actuator and ensures that the first actuator moves smoothly and linearly with respect to the second actuator. In use the pressurized hydraulic fluid is selectively admitted into the cylinder 36 and 44 on either side of the pistons 34, 42 of a pressurized hydraulic reservoir under the control of solenoid valves or the like which are controlled by an electronic controller, typically by the engine management system of the vehicle, in which the engine is accommodated to effect the desired movement of the assembly. By using the assembly 20, 26 the pivot on the shaft 21 can remain stationary and, while the crankshaft 10 rotates and the piston 4 moves alternately within the cylinder 2, the axis 16 of the crank 10 describes a circular path 29 and the rod 18 slides in and out of the first mounting member 20, which swings back and forth towards its axis 21. The mounting member 20 prevents the rod 18 from moving linearly transverse to sd length. The pivot of the shaft 12 is forced by the kinematics of the system to move along an irregular path 50, shown in the figure, which has an oval deformation or substantially an elliptical shape. Four specific positions which are occupied during one revolution of the crankshaft are designated as 12, 12 ', 12", 12"', respectively, and the corresponding positions of the axis 5 are designated as 5, 5 ', 5", 5 '' ', respectively. The mechanism results in the time / position graph of the piston that differs from the conventional sinusoidal shape, but the precise manner in which it varies will depend on the relative positions of axes 12, 16 and 21. These are predetermined to produce the required pattern of the movement of the piston, for example, one that approaches this in the engine is described in EP-A-0591153. The movement pattern of the piston can be varied by alternating the position of the assembly 20, 26 as well as the pivot of the axle 21. This can be done by selectively actuating the actuator 30 and / or the actuator 32 to move the axle 21 to any desired position. The movement of the piston of the shaft 21 can be effected at the end of one or more of the strokes of the piston during each cycle in order to produce different trajectories of movement in, for example, compression and escape of gases. Alternatively, it can be carried out in order to adapt combustion optimally to different speed and / or load conditions. As a further alternative the shaft 21 can be moved in the course of one or more of the strokes of the piston to produce a desired variation in the pattern of movement of the piston from the sinusoidal. In any event, the movement of the assembly can be effected extremely fast, for example, under the control of the engine management system which is now provided in the most modern automotive engines. The movement of the assembly by a control means can be effected in response to the manual operation of the control means by the user when following a decision, for example, to increase the sweep volume of the motor. However, it is preferred that the control means be automatically actuated in response to one or more detectors, which are arranged to produce signals indicative of the operating parameters of the motor. Thus, in this preferred embodiment the engine includes a blow detector adjacent to the cylinder, which operates in a known manner to indicate when the knocking or pre-ignition of the engine has begun or is about to begin. When such a signal is produced by the detector, the control means is arranged to drive the actuator 30, to move the assembly in a direction in which the compression ratio of the motor is reduced and thus prevent the knocking from occurring. The motor also includes a charge detector, for example, a pressure sensitive detector in the intake manifold or in the position of the shutter, which is arranged to drive the actuator 30, to decrease the compression ratio while the load is Increase As mentioned above, the compression ratio of the engine is varied by altering the top dead center position (TDC) of the piston, and changes in the ignition timing and / or volume in the piston sweep are compensated by moving the bottom dead center (BTC) position of the piston when actuating the actuator 32 to move the assembly in direction perpendicular to the axis of the cylinder. The engine of the specific embodiment includes four cylinders, and while each cylinder may be associated with its own first and second movable mounting members and with their actuators, this is not necessary. Thus in this modality there is only a single second mounting member 26, which is common to m ^^ ^ ijii ^ ^ all cylinders. There is also preferably only a single first mounting member 20 in the form of an elongated cylinder with four holes formed therein to accommodate the four bars 18. It is noted that with respect to this date, the best method known to the Applicant for carrying out said invention is the conventional one for the manufacture of the objects or products to which it refers. jSf ^ í ífijá A *** * au * -! * ^

Claims (9)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1. An internal combustion engine includes one or more pistons, each of which is mounted to move alternately in a respective cylinder and it is connected in a pivotable way to a connecting rod, which is connected to a respective crank 10 on a crankshaft, the connecting rod is pivotably connected to one end of an elongated joint member, which is pivotably connected to an associated crank at an intermediate point of its ends and whose other end constitutes a rod, the 15 which is fastened by such a mounting, which can rotate next to the shaft pivot, parallel to the crankshaft axis, characterized in that the assembly includes a first movable mounting member connected to a second movable mounting member that is further pivotable, with respect to 20 to the pivot of the shaft, the first movable mounting member is connected to the rod by a connection, which allows only the relative sliding movement in the direction of the rod, a first actuator is connected to the assembly and is arranged to move it in a manner 25 selective in a first direction perpendicular to the axis 5 of the crankshaft and that a second actuator is connected to the first actuator and ®s arranged to move it and mounting in a second direction transverse to the first direction.
2. 2. An engine as claimed in claim 1, characterized in that the first direction is substantially parallel to the axis of the cylinder and the second direction is substantially perpendicular to the axis of the cylinder.
3. 3. An engine as claimed in claims 1 or 2, characterized in that the actuators are of the hydraulic type. .
4. An engine as claimed in any of claims 1 to 3, characterized in that it includes a control means arranged selectively, to operate the first and second actuators.
5. 5. An engine as claimed in the rievindication 4, characterized in that it includes a first detector arranged to produce a signal indicating that the knocking of the motor is starting, the control means is arranged to operate the drive means to move the assembly in the first direction to decrease the compression ratio of the motor and thus cause the knocking to stop.
6. 6. An engine as claimed in the claims 4 or 5, characterized in that it includes a second detector arranged to produce a signal indicative of the load of the engine, the control means is arranged to move the assembly, in the first direction to vary the compression ratio of the engine with the change of load.
7. 7. An engine as claimed in claim 5 or 6, characterized in that the control means is arranged to move the assembly in the second direction, to compensate for the change in the stroke caused by the movement of the assembly in the first direction.
8. 8. An engine as claimed in claim 4, characterized in that it includes a second detector, arranged to produce a signal indicative of the load on the motor, the control means is arranged to move the assembly in the second direction to increase the volume of sweep by the piston while the load increases.
9. 9. An engine as claimed in any of the preceding claims, characterized in that the connecting rod is inclined towards the axis of the cylinder when the piston is in the upper dead center (TDC) position.