RU1782291C - Device for changing ratio of compression in piston internal combustion engine - Google Patents

Abstract

SUMMARY OF THE INVENTION: the device comprises an eccentric 5 in the upper head of the connecting rod 4, mounted on the piston pin 1, integrated in the cavity of the latter, a simple-acting hydraulic cylinder, the piston 10 of which, having the shape of a cup, is constantly mated within its stroke with the head 8 of the rod 6 , the shank 7 of which is fixed in the piston 2 of the engine. A plug 17 is installed at the end of the piston pin from the side opposite to the hydraulic cylinder spring 16, forming, together with the bottom of the hydraulic cylinder piston, its working cavity 18 connected by a channel 19 to a device for supplying control oil to

Description

FIELD OF THE INVENTION This invention relates to spark-ignition reciprocating internal combustion engines, diesel engines, and multi-fuel engines.

.Numerous attempts have been made to create internal combustion engines (ICE) with an adjustable compression ratio.

According to the search works of the leading companies in Germany on the prospects for the development of automotive power plants, the expected further reduction in fuel consumption will require significant structural costs and, in particular, cannot be achieved without regulation Ј on a working ICE.

Currently, the most developed designs of engines with PARSS and engines with an additional chamber in the cylinder head with variable volume.

 A design feature of pistons automatically adjusting the compression ratio (PARSS) lies in their ability to change the volume of the combustion chamber (CC) as a result of changing the distance between the plane of the piston head and the axis of the piston pin.

PARSS consists of two main parts: the internal piston (insert) and the external piston (shell). The inner piston is connected to the connecting rod by a piston pin. The outer piston is movable relative to the inner one and its relative position is determined by the amount of oil filling the upper or lower annular oil chambers. The oil in these chambers comes from the connecting rod through the check valves. At the end of the stroke, the inertia forces tend to move the outer piston upward relative to the inner one. The piston is prevented from moving by the oil in the lower annular chamber, but since there is a throttle hole in the chamber, then part of the oil flows out. The diameter of the throttle bore is chosen so that the outer pore

the tire moves up a certain amount (for example, for Continental 1100 diesel engines, the outer part of the piston moves 0.125 mm relative to

internal for the period of one cycle). Thus, to change the compression ratio from 10 to 22, 60-65 cycles (130 revolutions of the crankshaft) are needed, which at 2800 rpm is about 3 seconds.

The compression ratio will increase until the pressure reducing valve opens, with some of the oil flowing out of the upper chamber and the outer piston (casing) moving downward with respect to

internal piston (insert), as a result of which e and, accordingly, the load on the piston are reduced. A decrease in the compression ratio can occur only in the TDC zone when the mixture ignites, if the gas pressure transmitted to the upper oil chamber opens the pressure reducing valve. In steady state, the outer shell oscillates around some middle position relative to the inner

the insert connected to the connecting rod, rising on the exhaust and intake strokes and lowering the same amount during subsequent compression and expansion strokes. The compression ratio is automatically set. It is determined by the amount of tightening of the spring of the pressure reducing valve, which in turn depends on the permissible maximum cylinder pressure (Pz).

Analysis of studies of diesel engines with PARSS

shows that their designs are being continuously improved, but so far they have not been implemented except for Continental diesel 1100 series with S / D-127 / 123.8.

The disadvantages of PARSS should include

low reliability, determined mainly by the flaws in the operation of the valves, associated with a high sensitivity to contamination of oil by foreign particles, as well as due to increased

oil compressibility due to air inclusions and oil leaks through o-rings;

a large number of cycles (crankshaft revolutions) during which the compression ratio is changed from the mode with the highest compression ratio to the mode with the lowest compression ratio, which for gas engines will cause detonation combustion upon a sharp increase in load;

a significant increase in mass, for example, in a Continental AVDS-1100 diesel, the weight of the PARSS is 6.15 kg against 4.2 kg of a standard piston, i.e. 47% higher, as a result of which high-speed internal combustion engines significantly increase the inertial loads on the connecting rod bearing. In addition, the disadvantages include

the complexity of the hydraulic system;

a significant increase in the complexity of manufacturing;

for diesels with a high average effective pressure, in order to organize the required intensity of cooling of the piston head, it is necessary to make one more cavity (except for the two indicated) directly below the piston head and to supply and discharge cooling oil into this cavity, since in steady state, the oscillations of the outer shell of the piston cannot provide an intensive oil change under the piston head.

Due to the fact that a reduction in the compression ratio can occur only in the TDC zone when the mixture is ignited, with an increase in the rotation frequency, the time for which the pressure reducing valve opens is reduced, which creates certain problems in the implementation of the control process in high-speed engines of the class Spark ignition engine for passenger cars.

It is known that Volkswagen developed a camera with a variable e in the cylinder head of an internal combustion engine of a passenger car. A combustion chamber consists of a main chamber, the volume of which corresponds to the volume of the compressor at maximum e, and an additional chamber in the cylinder head with a variable volume. The change in its volume, and therefore, is carried out by means of a movable piston with two piston rings. The geometric ratio of the primary and secondary chambers is selected so that it can be changed from 9.5 to 15.5. The diameter of the engine cylinder is 79.5 mm, the diameter of the additional chamber in the cylinder head is 35 mm. The spark plug is mounted in the center of the control piston and, when the ICE is in operation, moves with it. The movement of the control pistons is carried out by an electromechanical device depending on the ICE load.

Tests of a car with an experimental ICE showed that it is no worse in dynamic and speed qualities than a car with a serial ICE. The fuel economy when checking ICEs with variable e for the case of vehicles driving in an urban ECE cycle, i.e. in the lower part-load region, is 13%.

The disadvantages of the described construction are

the possibility of implementing the design only for two-valve cylinder heads;

violation of the shape of the CS and the increased value of the surface of the CS at lower values of e.

Attempts are known to control the degree of compression in the internal combustion engine by varying the distance between the axle of the crank pin of the crankshaft and the piston pin.

A device of the Cooper-Bessemer company for changing the compression ratio of an internal combustion engine during operation is known. The device ensures the achievement of two predetermined degrees of compression: low when the load is higher than the specified value, and high when lower. In practice, in most cases, two given values of достаточно are sufficient.

In the lower head of the connecting rod, between the connecting rod bore and the connecting rod neck, an eccentric sleeve is placed.

However, the main disadvantage, which excludes the possibility of practical implementation of devices for changing the degree of compression with an eccentric sleeve in the lower connecting rod head, is that these bushings can be installed on the crank pins of the crankshaft only if they are detachable. An exception may be made only to motorcycle engines where collapsible crankshafts and collapsible connecting rods are used.

The thickness of the eccentric sleeve of the device is limited by the requirement of the dismantling of the connecting rod through the cylinder and the need to limit the mass of the lower head of the connecting rod, and therefore the average thickness of the eccentric sleeve is limited and cannot significantly differ from the thickness of the thick-walled liners used previously in ICE designs.

With a detachable eccentric sleeve (in the form of two liners) installed with a clearance in the bore of the connecting rod, it cannot be

ensuring the operability of the bearing assembly of the lower head of the connecting rod of the device.

A device for varying the compression ratio of Karl Schmidt (Germany) is known. In the proposed device, a change in the degree of compression is achieved by turning an eccentric sleeve T installed at an angle of up to 180 ° in the upper head of the connecting rod. The eccentric sleeve-bearing has a cylindrical outer surface and a cylindrical inner surface that is eccentric with respect to the outer surface. The device ensures the achievement of two predetermined degrees of compression. The rotation of the sleeve is limited by the thrust fingers located in the body of the connecting rod, which also serve as guides and seals for the grooves in the sleeve. The rotation of the sleeve is controlled hydraulically by pumping fluid into one of its slots. In certain positions, the sleeve is locked by a ball retainer that enters into the holes processed in the sleeve and connected to the grooves by grooves.

Compared to devices in which the eccentric sleeve is installed in the lower connecting rod head, the device with the eccentric sleeve in the upper connecting rod head has significant advantages: according to the assembly conditions, the sleeve is integral. due to the low sliding speeds in the bearing of the upper head of the connecting rod, the bearing can be made of a harder antifriction alloy, for example, of tin phosphor bronze without filling, which excludes cracking of the filling of the connecting rod bushings when the neck of the liner does not fit snugly to the bed; the moment from friction forces in the bearing of the upper head of the connecting rod is much smaller than in the lower head of the connecting rod due to the fact that the diameter of the piston pin is less than half the diameter of the connecting rod journal and due to lower sliding speeds in the bearing, which creates significantly greater possibilities for ensuring operability locking pins of the eccentric sleeve with its floating structure, i.e. when installing an eccentric sleeve with a clearance on both the piston pin and the connecting rod head; the installation of an eccentric entails an increase in the dimensions and weight of the bearing assembly compared to a conventional design. Moreover, due to the significantly smaller diameter of the piston pin compared with the diameter of the connecting rod neck and the smaller width of the upper head of the connecting rod compared to its lower head, the increase in the mass of the assembly with an eccentric sleeve in the upper head of the connecting rod will be significantly less than with that in the lower head.

However, this device has the following significant disadvantages;

the insignificant area on which the injected fluid acts when controlling the rotation of the sleeve is equal to the product of the groove width and the thickness of the sleeve with a very imperfect compaction of the groove cavity where this control fluid is supplied. In this case, the leakage of the control fluid through the gap between the guide pin and the walls of the groove and through the radial clearances between the sleeve and the piston pin and the sleeve and the connecting rod head fill the cavity of the groove behind the sealing pin and, when the sleeve is rotated, the fluid

the filling cavity behind the guide pin must be extruded into the radial gaps between the sleeve, the pin and the connecting rod head and create additional resistance to the rotation of the sleeve under the influence of the control fluid;

the presence of grooves reduces the bearing capacity of the connecting rod sleeve.

The floating sleeve (with gaps between the piston pin and the connecting rod head) is not used in traditional engine designs and, therefore, the introduction of the proposed device 7 implies additional difficulties in the design and refinement.

A Volkswagen device for spark ignition automotive ICEs is known. The device provides a change in the degree of compression (e) depending on the load from 9 to 15. Between the piston

an eccentric sleeve with a curved groove on its side surface is mounted with a finger and a hole in the upper head of the connecting rod. The eccentric sleeve is mounted on the piston pin in hotter

condition. The end of the eccentric sleeve enters with a gap the end of a cylindrical pin rigidly fixed in the connecting rod head. Flat rings are installed between the ends of the sleeve and the piston bosses.

so that the sleeve cannot move in the axial direction, while a gap is provided between the ends of the upper head of the connecting rod and the piston bosses on both sides, as a result of which the connecting rod can

move in the axial direction, thereby causing the eccentric sleeve to rotate and thereby move the piston in the axial direction, which is accompanied by a change in e. The connecting rod moves axially

direction along with the crankshaft, for which a threaded connection with a lever is provided on its extreme main bearing. Turning the lever causes axial movement of the crankshaft in a special nut, while the maximum value of this movement does not exceed ± 2.5 mm.

The lever of this nut is connected to the throttle actuator and oscillates synchronously with its rotation. An actuating pneumatic element may be used.

The disadvantages of the device are as follows.

Structurally, to allow axial movement of the connecting rod, it is necessary to have gaps between the ends of the upper head of the connecting rod and the ends of the piston bosses. The size of these clearances is limited, which leads to small displacements of the connecting rod relative to the eccentric sleeve ± 2.5 mm with a change in e and, accordingly, a small angle of elevation of the curved (screw) groove. Further, due to the fact that the connecting rods are shifted in all cylinders of the multi-cylinder engine, the eccentrics turn inevitably at the same time in some or in some cylinders at elevated pressures in the cylinder (at the end of compression or during the working stroke), which at a small angle of elevation of the screw When moving the connecting rod, the line causes increased efforts in the pair of the finger - screw groove, which accordingly reduces the reliability of the unit and its durability.

Due to the small axial displacement of the connecting rods, the accuracy of setting the degree of compression in different cylinders of a multi-cylinder engine will be low, i.e. there will be an increased scatter Ј in the cylinders.

The presence of gaps between the ends of the upper connecting rod head and the ends of the piston bosses provided for moving the connecting rod reduces the strength of the piston and reduces the bearing surface of the bearings. This limits the scope of the present invention, because in high-speed diesel engines, P z-140 kg / cm2 is currently implemented, and in medium-speed diesel engines - 140 ... 180 kg / cm2, while the stresses in the piston bosses are so high that the use for medium-speed diesel engines has been abandoned. thrones of pistons of aluminum alloys with their replacement by high-strength cast iron.

In the design of the drive of the auxiliary units and in the control of the clutch, the presence of axial movement of the crankshaft must be taken into account.

Fifth, axial displacements of the crankshaft are unacceptable for medium-speed diesel engines due to a decrease in the bearing capacity of crankshaft bearings due to a decrease in their width, complicating the connection of the crankshaft with power take-off units and reducing the reliability of the connection.

For all engines, regardless of size and forcing, periodic reciprocal axial displacements of the shaft necks relative to the bearings are unacceptable, since reduce the reliability of this pair due to a violation of the mutual running-in time and can cause scuffing due to uneven wear of the shaft necks in different modes of operation of the internal combustion engine.

The purpose of the invention is to improve the health and resource of the device and

0 expanding its possible field of application by forced automotive and medium-speed diesel engines.

This is achieved by the fact that the device for changing the compression ratio comprises a hollow piston pin fixed in the piston 6 of axial displacements with an eccentric fixed to it, mounted in the upper head of the connecting rod and equipped with a device for turning it;

0 containing a simple-acting hydraulic cylinder built into the cavity of the piston pin, consisting of a piston of a hydraulic cylinder having the form of a cup and a spring mounted between the piston lock

5 fingers from axial movements and the piston of the hydraulic cylinder, a rod equipped with a shank fixed in the piston from angular and axial movements, and located in the middle part of the cavity

0 of the piston pin with a head permanently mating with the internal cavity of the piston of the hydraulic cylinder within its stroke, a plug in the end of the piston pin mounted on the side opposite

5 to the spring, and forming in the piston pin together with the bottom of the piston of the hydraulic cylinder the working cavity of the hydraulic cylinder connected by a channel or channels to a device for supplying oil

0 control to the specified cavity of the hydraulic cylinder, or withdrawal from it depending on the load level of the engine, while the piston pin, piston of the hydraulic cylinder and rod heads are provided with elements,

5 made in the form of grooves and associated protrusions and engaging the piston of the hydraulic cylinder with the rod and with the piston pin within the stroke of the piston of the hydraulic cylinder, while the grooves of one

or both of these piston connections

hydraulic cylinders are made curved, in the latter case, with the opposite direction of the helical lines, moreover, each of the curved grooves is made with an angle of elevation of the helical line greater than the friction angle in the helical pair formed by the groove and the protrusion associated with it.

For example, the following embodiments of the joints are provided, which allow the piston of the hydraulic cylinder to grip with the piston pin and the rod head: a groove is made on the outer surface of the hydraulic piston and the piston pin is provided with a radial finger pressed into its wall and mated with the groove on the hydraulic piston; a groove is made on the rod head, and the piston of the hydraulic cylinder is provided with a radial pin pressed into its wall or a protrusion made integrally with the piston wall mating with the specified groove on the rod head.

The number of grooves and associated protrusions is set during design and is not affected by the nature of the device.

To increase the manufacturability of the protrusions and grooves on the piston of the hydraulic cylinder, the latter can be made with a detachable bottom, both fastened and not fastened to the piston throne.

The piston stroke of the hydraulic cylinder inside the piston pin in the proposed device can be made substantially larger than the movement of the upper connecting rod head between the piston bosses in the known device, and the screw groove can be made with a large angle of the helix (with a large pitch).

Both grooves, both on the rod head and on the outer surface of the piston of the hydraulic cylinder, can be made curved, with different directions of helical lines, which allows increasing the lifting angle of each of these grooves by about half.

The foregoing provides lower efforts in screw pairs in the proposed device and greater accuracy of the angular position of the eccentric.

In addition, in the proposed device, the switching force of the piston is determined by the force of the spring, the oil pressure and the area of the piston of the device, which is used. includes the movement of the piston during periods of high pressure in the cylinder of the engine, which is not excluded in the prototype.

Consequently, the proposed device has created the prerequisites for achieving greater reliability and durability.

The proposed device does not require special increased gaps between the upper head of the connecting rod and the ends of the bosses to rearrange the connecting rod, which

Compared with the prototype, it increases the strength of the piston and allows the device to be used in diesel engines with high maximum cycle pressures.

The proposed device does not require

0 axial displacements of the crankshaft with a change in the compression ratio, which allows it to be used in large diesels.

The proposed device 5 is characterized by a significantly larger surface area exposed to the control fluid and a significantly better sealing of the cavity where this fluid is supplied.

0 Moreover, in the proposed device due to the expansion of forces at the point of contact of the finger with a curved groove, the force turning the eccentric is approximately two to three times higher than the axial force by

5 piston of the hydraulic cylinder, which increases the reliability of the proposed device and requires less pressure of the control fluid.

The proposed device has

0 greater working capacity of the bearing assembly of the upper connecting rod head due to the absence of special grooves in the bearing to control its rotation, and the length of the piston pin allows you to place a spring, creating a simple-acting power cylinder to rotate the eccentric and, accordingly, supply control fluid from only one side hydraulic cylinder piston, which greatly simplifies the device for supplying and discharging control fluid.

Variant 1 of a device supplying control oil to the cylinder cavity 5 in the piston pin or diverting from it depending on the engine load level comprises an oil receiver that selects control oil from the oil supply channel in the engine connecting rod mounted in the piston in the hole under the piston pin, and connected by channels in the piston to the oil receiver, a distributor consisting of a momentary hydraulic cylinder and a distribution valve 5 secured to the blade of the latter and two fixed nozzles ynogo drive cylinder blade connected to the engine lubrication system or a standalone the oily circuit through a control device varying the degree

squeeze. Depending on the position of the hydraulic cylinder blade, which is determined by the oil supply to one or another control nozzle, the distributor valve connects the hydraulic cylinder cavity in the piston pin either to the oil receiver cavity or to the drain.

Option 2 of the device, which supplies control oil to the hydraulic cylinder cavity in the piston pin or withdraws from it depending on the engine load level, contains a piston built into the throne, under the piston pin and parallel to it a distribution valve provided with an internal cylindrical cavity and connected to this cavity radial channel telescopically connected to the distributor valve using a tubular shank mounted in the bore of the distributor valve, oil receiver, polo which is open to the end surface of the connecting rod, sealed with the latter by means of springs and mating with an oil supply channel in the connecting rod brought to the specified end surface, channels in the piston and in the plug installed in the end of the piston pin, connecting at the angular position of the spool corresponding to the supply of oil to the cavity of the hydraulic cylinder, the radial channel in the spool with the cavity of the latter, and when the angular position of the valve, corresponding to the discharge of oil from the cavity of the hydraulic cylinder, connecting the latter by means of a groove, made on the side surface of the spool, with a drain channel in the piston, a mechanism for changing the angular position of the distributor valve, comprising a rocker arm with bowl-shaped blades mounted on the distributor valve and two jet drive nozzles directed to said bowl-shaped blades and connected to the engine lubrication system or to autonomous oil circuit through a compression ratio control device.

The control device for variants 1 and 2 of the above devices supplying control oil to the hydraulic cylinder cavity in the piston pin or supply from it contains a switching contact mechanically connected to the rail of the high pressure fuel pump, shut-off valves with an electrically controlled actuator, installed on the oil supply pipelines to the jet drive nozzles from the engine oil line or from an autonomous oil circuit, electric communication lines connecting the switching contact with the electric device actuated shut-off valve via time relay.

Figure 1 shows a General view of the device 5 in the low compression position; figure 2 - the same, in the position of a high degree of compression; in Fig. 3 - view A of the connection of the shank of the rod of the device with the piston tronk; figure 4 is a section bB (according to the distribution 0 of the body in the position of the latter, corresponding to the installation of the device at a low compression ratio); figure 5 - section GG (on the distributor in the position of the latter, corresponding to the installation of the device 5 for a high degree of compression); FIG. 6 is a section B-B (along the oil drain channels from the cavity of the spring of the retainer of the blade of the instant hydraulic cylinder); Fig. 7 is a section D-D (along the latch for the angular position of the housing of the torque cylinder in the piston); Fig. 8 is an embodiment of the oil supply to the distributor with the installation of a check valve; figure 9 - design of the check valve in the embodiment

5 in FIG. 8; in FIG. 10 is an embodiment of a spool valve; Fig. 11 is a diagram of a control device for changing the compression ratio for the devices shown in Figs. 1, 2, 4 ... 10 and Figs. 27, 28; in Fig. 12, a device for supplying control oil to the cavity of the hydraulic cylinder in the piston pin or withdrawing from it (version with a two-blade rotary switch of the distributor valve); on the

5 FIG. 13 is a cross-section EE in FIG. 12 (diagram of oil channels in the piston; in Fig. 14 is a sectional view FJ in Fig. 12 (a fragment of the lever drive of a two-blade switch); in Fig. 15 is a section 3-3 in Fig. 12 (position

0 blades of a two-bladed switch with a low compression ratio); in FIG. 16 - the position of the blades of the two-blade switch of the device of Fig.12 in the initial moment of switching

5 distribution spool; in FIG. 17 shows the position of the blades of the two-blade switch of the device of FIG. 12 at a high compression ratio; in FIG. 18 is a sectional view II in FIG. 12 (relative relative position of the distribution spool channels and oil supply channels at a low compression ratio); on Fig - node 111 in fig. 18 (relative relative position of the distribution spool channels and

5 oil supply and drain channels with a high degree of compression); Fig. 20 is a diagram of a compression ratio change control device for the devices shown in Figs. 12 ... 19 and 23 ... 26; in Fig.21 - node IV of Fig.12 (an embodiment of the mechanism for

switching the distribution spool of the device shown in Fig. 12); on Fig - section KK in Fig.21 (shows the switching of the distribution valve); Fig. 23 shows a device supplying control oil to the cavity of the hydraulic cylinder in the piston pin or withdrawing from it (version for selecting control oil from the end face of the connecting rod upper head and the two-blade rotary switch of the distributor valve); Fig. 25 is a section M-M in Fig. 23 (relative relative position of the distribution spool channels and oil supply channels at a low compression ratio); in Fig.24 - section L-L in Fig.23 - according to the oil receiver; in Fig.26 - the position of the channels of the distribution valve and oil supply and drain channels of the device in Fig.23 with a high degree of compression); Fig. 27 is a device for supplying control oil to the hydraulic cylinder cavity in the piston pin or withdrawing from it (version with the selection of control oil from the end of the connecting rod upper head and the control valve switch with the jet drive nozzles); in Fig.28 is a section HH in Fig.27 (shows the switching of the distribution valve); Fig. 29 is a connecting rod with a check valve integrated in the control oil supply channel.

The device comprises a hollow piston pin 1, fixed in the piston 2 from axial movements by the retaining rings 3, placed on the upper head of the connecting rod 4, an eccentric 5, mounted on the piston pin 1 for landing with a guaranteed tension, the rod 6, consisting of a shank 7 fixed in the piston from angular movements and a cylindrical head 8 located in the middle part of the cavity of the piston pin and provided with a screw groove 9, the piston 10, having the shape of a glass with a diameter of the internal cavity large of the rod head, installed in the polo the piston pin and provided with a screw groove 11 on the outer side surface and a pin 12 pressed into a radial hole in the piston wall 10, mating with a screw groove 9 on the rod head b, a pin 13 pressed into the radial hole in the piston pin wall, mating with the groove 11 piston 10, a thrust disk 14 installed between the end of the piston pin and the retaining ring 3 and bolted 15 with the shank 7 of the rod 6, a spring 16 installed in the cavity of the piston pin between the thrust disk 14 and the piston 10, the plug 17 in the torus no piston pin on the side

opposite spring 16, which forms, together with the bottom of the piston 10, a working cavity 18 of a single-acting hydraulic cylinder 18 with a piston 10 and a spring 16 connected by a channel 19 to a device that supplies control oil to or from the specified cavity 18 depending on the engine load level, this bottom of the piston 10 and the plug 17

equipped with o-rings 20 and 21, the stem head 6 is provided with an end protrusion 22, which serves as a limiter of the extreme left position of the piston 10, while the end face of the plug 17 serves as a limiter of its extreme right position, a washer 23 is installed between the supporting surface of the spring 16 and the end of the piston 10 , the thrust disk 14 is provided with holes 24 for draining oil that has leaked from the cavity 18 into the cavity for installing the spring 16, the cam 5 is installed in the bearing of the upper connecting rod head with a clearance, and the piston pin in the piston bosses Providing a clearance, on

at least when the engine is warm, the pins 12,13 fit into the screw grooves adjacent to them, 9 and 11, respectively, with a gap allowing them to slide along the groove, groove helix lines

9, 11 are oppositely directed, i.e. one of the grooves is in the right direction, the other is in the left, moreover, each of the screw grooves 9.11 to prevent self-braking of the piston 10 when moving it is made with an angle of elevation of the helical line I greater than the angle of the train between the surfaces of the grooves and pins, preferably with I 2 / e, and from the condition that the eccentric sleeve rotates 180 ° when the piston 10 moves between its extreme positions, the elevation angles of the helical lines of the grooves 9 and 11 are related to the stroke of the piston in accordance with the following relationship:

1-1- 1, 1 jrdi dM l dz tg Dg 2 N

where H is the stroke of the piston 10; Ai, dt — elevation angle and average diameter of the screw groove 9, respectively; Yaa, d2 - the same, groove 11.

To simplify the manufacture of the device, one of the grooves 9 or 11 can be made linear, while the design of the proposed device (the length of the piston pin) allows, in this case, to have a helix angle of another

the groove is several times higher than the practically necessary angle of elevation A 2p.

A suitable number of grooves and associated protrusions for engaging the piston 10 with the piston pin bis rod is established when developing a particular device.

The following options are possible for using elements of the device, the appropriateness of which depends on both mass production and, accordingly, manufacturing technology, and on the dimension and type of engine.

The protrusions in the internal cavity of the piston 10, coupled with grooves on the rod head, both rectilinear and screw, can be made integrally with the body of the wall of the piston 10 on Maad gear-grinding machines or, for example, are obtained by electric discharge machining with a profile electrode or machining by rolling in a combination of the rotational movement of the workpiece and the profiled electrode-tool with appropriate feeds. The latter method, as is known, is effective for the manufacture of parts with complex protrusions and depressions, while EDM can be used at all stages of the production of parts, since It provides 5 qualifications (degree of accuracy) and a metal removal rate of 10,000 mE / min with a machine power of 10 kW.

The bottom of the piston 10 can be made in the form of a separate part fastened or not fastened to the skirt of the piston 10, which will not lead to disruption of the interaction of the parts of the device.

The feasibility of such an embodiment of the piston 10 is determined by the accepted technology for manufacturing the external screw groove (s) 11 and the internal protrusions, the latter, for example, by pulling, and it is possible to perform on the piston skirt 10 not only external but also internal grooves the interface of the latter with the protrusions on the rod head 6, and the protrusions can be formed as radial pins pressed into the rod head, or made integrally with the body of the rod head.

The engagement of the piston 10 with the piston pin and with the rod head 6 can also be accomplished by splined joints — linear or screw.

The possible embodiments of the elements of devices that engage the piston 10 with the piston pin and with the rod head 6 are described.

the need to describe these elements in the claims in a general way.

To reduce the stiffness of the spring 16 should be installed, if this allows structurally allows the thickness of the piston wall, not one, but two concentrically spaced springs with mutually opposite direction of winding type valve springs.

To reduce the mass, the eccentric sleeve 5 is expediently made of technical ceramics, while the mass reduction of the upper connecting rod head is also achieved by the possibility of installing the ceramic eccentric directly in the hole of the upper connecting rod head, without the bearing sleeve in the latter.

Such an eccentric installation is also possible in the manufacture of the latter from an antifriction metal or when an antifriction layer is applied to its outer surface. It is possible and pressed into the upper head of the connecting rod of the bearing sleeve, as shown in Figs. 23 and 25.

The device operates as follows.

In the absence of oil pressure in the cavity 18, the piston 10 of the hydraulic cylinder is pressed by the spring 16 to the extreme right position, while the cam 5, as shown in Fig. 2, occupies a position corresponding to a high compression ratio.

When a control fluid is supplied to the cavity 18, the pressure of the piston 10 moves to the left, against the end of the rod end 22, while the pin 12 of the piston 10, moving along the screw groove 9 of the rod rotates the piston 10 and, accordingly, the finger with the eccentric sleeve 5 by an angle

N.

"1 :

 360. At the same time for

l6} tg / T

by moving the pin 13 in the screw groove 11, the piston 10, the piston pin with an eccentric 5 additionally rotates LJ

with a corner j 1 360 °, while

how the total angle of rotation of the piston pin with the eccentric is structurally set to be a + az 180 ° and the eccentric 5 will occupy the position shown in Fig. 1 corresponding to a low compression ratio.

When the cavity 18 is connected to the drain, the spring 16 presses the piston 10 to the extreme right position, as a result of which the screw pairs of the device rotate the finger with the eccentric in the opposite direction by 180 ° with a high compression setting.

In the case of manufacturing one of the grooves, for example, the groove 9 is rectilinear, the operation scheme of the device changes only in that in this embodiment, the rotation of the piston pin with the eccentric 5 is carried out only by moving the pin 13 along the screw groove 11, but while ensuring the design of the angle of rotation of the AC 180 °.

The following are variants of a device for supplying or discharging control oil to the cavity 18 of the hydraulic cylinder, and in all cases, oil from the engine lubrication system is used as the control fluid.

A device that supplies control oil to the cavity of the hydraulic cylinder 18 in the piston pin or withdraws from it depending on the engine load level, shown in Figs. 1,2,4 ... 10 (embodiment), contains a distributor 25 and fixed nozzles 26 , 27 of a jet drive connected to the engine lubrication system or to an autonomous oil circuit through a control device for varying the compression ratio depending on the engine load level, an embodiment of which is shown in Fig. 11.

The distributor 25 contains a torque hydraulic cylinder 28, the blade 29 of which is fastened to a rotary type spool valve 30 integrated in the housing of the torque hydraulic cylinder and connected to the oil receiver cavity 31 by channels 32, 33, 34.

A latch 29 is integrated in the vane 29, consisting of a pin 35 provided with a cylindrical slope 36 mounted with a small gap in the cavity of the vane and a spring 37 providing a locking force.

The wall of the hydraulic cylinder has sockets 38, 39 under the head of the finger 35 of the retainer and located at the peripheral points of the cavity of the hydraulic cylinder 28, on different sides of the blade 29, channels 40, 41 connected through channels in the piston with nozzles 26.27, respectively. Said sockets 38, 39 and channels 40, 41 are interconnected by grooves 42, 43, as shown in FIGS. 4 and 5.

The spool 30 has a Central hole 19 connected to the radial hole 44, aligned in accordance with. the position of the blade of the hydraulic cylinder, or channel 32 for supplying oil (figure 4), or with a drain channel made in the body of the hydraulic cylinder in the form of holes 45 and groove 46 (figure 5).

As shown in Fig.6, the cavity of the retainer spring through the hole 47 and the flange 48 in the spool is permanently connected to the drain hole 49 in the cylinder body, and the discharge hole 50 in the spool communicates the cavity 18 in the piston pin with a cavity 51 between the end face of the spool and the torque housing hydraulic cylinder.

To fix the angular position of the distributor 25 in the piston, the housing of the torque cylinder 28 is provided with a pin 52 that fits into the groove 53 in the piston, as shown in Fig. 7.

An embodiment of the supply of oil from the cavity of the oil receptacle 31 to the distributor 25 shown in Fig. 8 contains a check valve 54 for disconnecting the cavity 18 in the piston pin with the cavity of the oil receptacle 31 at the moments of reduced oil pressure in the latter, determined by the inertia forces acting on the oil, located in the channels of the mobile oil line and own hydrodynamic vibrations in the lubrication system.

The need to install a check valve arises if, at times of reduced oil pressure, the spring force exceeds the force from the oil pressure, because oscillations of the piston 10 may occur, resulting in local wear of the screw pairs. However, the installation of a non-return valve should be resorted to only having exhausted the possibilities of constructive improvement of the design of the elements of the oil system, in particular, the design of the channel elements of the crank mechanism.

Fig. 9 (assembly I) shows the design of the non-return valve 54. The valve consists of a cylindrical body 55, the actual valve 56 and a weak spring 57, which presses the valve against the seat of the body. The valve body is installed in the piston 2 with tension on the outer diameter. The relationship of the oil channels 33.34 in the piston 2 with the channels in the sleep valve from the drawing.

In the embodiment of FIG. 10 (assembly II), the spool 30 is provided with a flat 58 connecting the oil supply channels 32 and the drain 45 in the device position corresponding to the setting of a larger compression ratio in FIG.

The described device supplying control oil to the cavity of the hydraulic cylinder 18 or withdrawing from it, shown in Figs. 1, 2, 4 ... 10, operates as follows.

In order to change the compression ratio, control oil is supplied to one of the nozzles 26 or 27 (to the nozzle 26 - by command to set a low compression ratio to the nozzle 27 -

high compression setting command).

At the nozzle exit, the kinetic energy of the oil stream is converted to pressure energy. Focusing on jet tube distributors, in which the pressure in the power cylinder is about 90% of the pressure supplied to the tube, it is possible to count in the above design on a rather efficient conversion of the kinetic energy of the oil flow at the nozzle exit to the pressure in the rotary cylinder 28 during finding the internal combustion engine piston in the zone of bottom dead center.

.. When the oil is supplied to the nozzle 26, the blade 29 of the torque cylinder is moved from the position shown in Fig. 5 to the position in Fig. 4. The oil is supplied to the nozzle for a predetermined period of time sufficient to effect a switchover, and then shuts off.

At the initial moment of switching, the control oil, entering through the groove 42 under the cylindrical juice 36 of the retainer pin, compresses the spring 37, making it easier to eject the retainer pin 35 from the socket 38 when switching. Having received freedom of movement, the blade 29 of the hydraulic cylinder receives oil pressure from the nozzle into the cavity of the hydraulic cylinder, rotates all the way to the opposite wall of the hydraulic cylinder relative to the initial position of the blade and is locked by the latch in this new position, shown in Fig. 4, while the radial hole 44 in the gold ke 30 is aligned with the channel 32 for supplying oil from the cavity of the oil receiver 31, ensuring the flow of oil from the latter into the cavity 18.

When oil is supplied to the nozzle 27, the blade 29 of the torque cylinder is moved from the position shown in Fig. 4 to the position in Fig. 5, in which the radial hole 44 in the spool 30 is aligned with the drain channel 45, allowing the oil to be drained from the cavity 18.

The ejection of the retainer pin and socket 39 at the initial moment of switching occurs similarly to that described above with the oil being supplied under the cylindrical juice 36 of the retainer finger using the groove 43.

As shown in FIG. 5, when the cavity 18 is connected to the drain, the spool 30 closes the hole 32, as a result of which the oil supplied through the connecting rod to the oil receiver. in these modes the piston is completely cooled, but due to the fact that this position of the device corresponds to the partial load and idle modes,

it may be appropriate for the diesel engines in these modes to connect the cavity of the oil receiver 31 to the drain, thereby achieving an increase in the temperature of the piston head, which favorably affects the flow of the working process. In the embodiment of the device shown in FIG. 10, with the device position corresponding to the high compression ratio setting, the flat 58 on the spool 30, connecting, as shown, the oil supply channels 32 to the control valve and 45 - oil drain reduces the oil flow for cooling the piston head.

A control device for varying the compression ratio as a function of the load level for a multi-cylinder diesel engine, shown in FIG. 11, comprises a switching contact 59 with a mechanical coupling 60 of the latter with a rail 61 of a high-pressure fuel pump 62 connected to a speed controller 63, a manifold 64 of nozzles 26, an inkjet actuator connected through an isolation valve 65 with an electrically actuated actuator to oil line 66 of the engine, manifold 67 nozzles 27 of the jet drive, connected via a shut-off valve 68 with electrically controlled supply to the oil line 66, electric lines 69.70 connecting the switch 59 to the electrically controlled valve actuator Anov 65, 68 through a time relay 71.

The device of FIG. 11 also contains a start button 72 with two pairs of contacts: a normally closed pair of contacts 73 on the electric communication line 69 and a normally open pair of contacts 74 on the electric communication line 75 of the power supply of the electric starter relay when the engine is electrically started or the main start valve during air start of internal combustion engine.

The control device operates as follows.

The diesel load level is determined by the output of the fuel pump rail, which determines the cyclic supply of the latter.

When the load is above a certain predetermined level, the switching contact 59 moved by the rail of the fuel pump closes the electric communication line 69, while the actuator of the shut-off valve 65 opens the last and control oil from the line 66 enters the manifold 64 of the nozzles 26 of the jet drive. When the oil is supplied to the nozzles 26, as described above, the distributors 25 are moved to a position corresponding to the low compression setting (to the position in Fig. 4). The oil supply to the nozzles 26 is turned off by the roller of the premium 71. which breaks the communication line 69 after the time set for switching the valve 25 has passed.

When the load is reduced, at the time specified at the output of the fuel pump rail, the switching contact 59 closes the electric communication line 70, while the shut-off valve actuator 68 opens the last one and control oil from the line 66 enters the manifold 67 of the nozzle 27 of the jet drive. When oil is supplied to the nozzles 27, as described above, the valves 25 are moved to a position corresponding to a high compression ratio setting (to the position in Fig. 5). The oil supply to the nozzles 27 is turned off by the time relay 71, as when controlling the oil supply to the nozzles 26.

Since most medium-speed diesels do not have a fuel pump rail output limiter at start-up, circuit 11 provides for a break in the communication line 69 during the start-up period of a diesel engine by pressing the start button 72 to exclude the possibility of oil supply to nozzles 26 and installation at start-up of a low compression ratio .

Similarly, a control device for a carburetor engine can be made by mechanically coupling a switching contact 59 to a throttle actuator.

The simplest control device circuit can be implemented on diesel locomotives and heavy trucks, where the closure of the electric circuits 69, 70 for controlling the oil supply valves 65, 68 at the nozzles of the jet drive 26, 27 can be carried out directly by the handle of the driver's controller. 1 For engines with a microprocessor control system, a change in the degree of compression (oil supply to a particular nozzle of a jet drive) can be carried out according to the signals of several sensors of the operating parameters of the engine, as well as the knock sensor of engines with spark ignition.

A device for supplying control oil to the cavity of the hydraulic cylinder 18 in the piston pin or withdrawing from it depending on the engine load level shown in FIG. 12 ... 20 (embodiment), contains a piston integrated in the throne, under the piston pin and parallel to it. a distribution valve comprising a rotary valve spool 76, provided with radial channels 77 and 78, interconnected by a central channel 79, channels 80, 81, 82 in the piston connecting the radial channel 77 in the valve with the oil receptacle cavity 31 at the angular position of the valve the control oil into the cavity 18, the channels 83.84.85 connecting, at the indicated position of the valve, the radial channel 78 in the valve with the cavity 18, and at the angular position of the valve corresponding to the removal of the control oil from the cavity 18, connecting the last means for na0 86 formed on the side surface of the spool 76 to the spill passage 87 in the piston (see. Fig. 19), the mechanism for varying the angular position of the spool, comprising a rocker (double-arm lever) 88,

5 mounted on a slide valve, a rotary two-blade switch 89 mounted on a control shaft 90 located in a support 91 parallel to the axis of the piston pin and connected by a lever gear with a control device for changing the compression ratio (the embodiment of which is shown in FIG. 20), while the lever the transmission comprises a lever 92 mounted on the control roller 90, and

5 pivotally connected to the lever 92 of the rod 93, the support 91 is centered in a bore made in the transverse wall 94 of the engine crankcase and provided with spacers 95 for adjusting the longitudinal position of the switch 89 relative to the rocker arm 88, the spool 76 is provided with latches for its axial and angular position, the first of which is made in the form of a groove 96 on a spool and

5 of the set screw 97, the second contains a spring-loaded ball 98 and two slots for it in the spool for fixing the latter in the two positions described above: supply of control oil to the cavity 18 and outlet

0 specified oil from this cavity.

The described device supplying or withdrawing control oil to the cavity of the hydraulic cylinder 18, shown in FIG. 12 ... 20, works as follows

5 way.

The blades of the switch 89, acting on the shoulders of the rocker arm 88, set the latter depending on the angular position set by the control device

0 of the control roller 90, either to the position shown in Fig. 15 or to the position in Fig. 17.

When the position of the rocker arm 88 shown in Fig.15 (section 3-3) radial

5, channel 77 in the spool is aligned, as shown in FIGS. 12 and 13 (section along E-E), with channel 80 in the piston 2, and the radial channel 78 in the spool is aligned with channel 83, as shown in FIG. 12 and FIG. 18 (II-section), wherein the oil from the oil receptacle cavity 31 enters the cavity 18, providing, as described above, a low compression ratio setting.

To set the compression ratio to a high degree, the rotor blades are rotated by the roller 90 to the position shown in FIG. 16, 17. In this case, at the initial moment of changing the angular position of the spool 76, shown in FIG. 16, the right shoulder of the rocker arm 88 when the piston 2 of the engine moves to the bottom dead center (BDC) and at a certain distance from the latter, determined by the size of the links and their angular position, which is clear from FIG. 16, collides (comes into contact) with the right blade of the switch and, upon reaching the BDC, is transferred to the position shown in FIG. 17. At the same time, the spool 76 overlaps the outer surface of the channel 80 for supplying oil to the spool 76 from the oil receiver and connects the channel 83 through the groove 86 to the drain channel 87 in the piston, as shown in FIG. 19, discharged oil from the cavity 18.

The translation of the rocker arm to the originally considered starting position in FIG. 15 from the position in FIG. 17 is carried out similarly to the described translation of the rocker from the position in Fig. 15 to the position in Fig. 17, only with this change in the angular position of the rocker the left shoulder is moved by the left blade of the switch.

The installation of the control roller 90 in one or another angular position - in Fig. 15 or in Figs. 17 is a control device for varying the compression ratio depending on the load level, a possible embodiment of which for a diesel engine is shown in FIG.

The control device of FIG. 20 contains a closing contact 99 with a mechanical connection 60 of the latter with a rail 61 of the high-pressure fuel pump 62 connected to a regulator 63, mounted on the longitudinal wall 100 of the engine crankcase, a single-acting pneumatic cylinder 101, the rod 102 of which is connected through a lever transmission with rods 92 of the drive of the control rollers 90 of two-blade switches 89, an electro-pneumatic valve 103 for controlling the supply of compressed air to the pneumatic cylinder 101 from the compressed air line 104 of the control, an electric line communication-parameter 105 connecting the valve 103 elektropnevmetichesky make contact 99, the linkage connecting the stem 102 with the connecting rods 93 comprises pivotally connected to said connecting rods levers 106 mounted on a common for all cylinders

a roller 107 installed in bores made in the transverse walls of the crankcase of the engine and connected by a lever 108 fixed thereto (in Fig. 20 aligned with a lever 106) and an earring 109 with a rod 102, the latter having a travel stop 110 spacing the piston of the pneumatic cylinder, and spacers 111 are introduced between the pneumatic cylinder 101 and the wall of the crankcase 100 to expose the angular position of the two-blade switch 89.

The control device operates as follows.

In accordance with the fact that the position of the rocker arm 88 and the two-blade switch 89 in Fig. 20 corresponds to a lowering of the latter in the aforementioned Fig. 17, the control device in Fig. 20 is in a high compression setting position.

When the load is above a certain predetermined level, the make contact 99 moved by the rail of the fuel pump closes the electric communication line 105, while the electro-pneumatic valve 103 opens the access of compressed air from the pipeline 104 to the working cavity of the pneumatic cylinder 101. As the pneumatic cylinder enters the pneumatic cylinder, it presses the piston of the latter into the leftmost position defined by the travel stop 110 is carried out by means of a lever

5, turning the control roller 90 and setting the two-blade switch 89 to the position shown in FIG. 15, the switch 89, acting with the left blade on the left shoulder of the rocker arm 88, sets the rocker to the position shown in FIG. 15, and the installation is achieved low compression.

When the load is reduced, at the moment set at the output of the fuel pump rail,

5, contact 99 opens the electric communication line 105, while the electro-pneumatic valve 103 blows air from the working cavity of the pneumatic cylinder, the spring of the pneumatic cylinder squeezes the piston of the latter

0 the extreme right position, by means of a lever transmission, rotates the control roller and sets the two-blade switch 89 to the position shown in Fig. 17 and described in Fig. 20.

5 The switch 89, acting with the right blade on the right shoulder of the rocker arm 88, sets the latter to the position shown in Fig.17 and Fig.20. a high compression ratio is achieved.

The circuit of this device may include breaking the electric communication line 105 when starting the diesel, as is done, for example, in the circuit of the control device of Fig. 11.

Fig. 21 (callout IV of Fig. 12) and Fig. 22 (K-K section of Fig. 21) show an embodiment of a mechanism for changing the angular position (switch) of a rotary type spool valve 76 in the above-described device of Fig. 12.

The mechanism comprises a lead 112 mounted on the spool 76, provided with a roller 113, a rail 114 with a groove formed by profile surfaces 115 and 116, in contact with the lead roller when the angular position (switch) of the spool 76 changes, provided with cylindrical pins 117, 118, with sliding dowels 119, 120 mounted axially movable in bearings fixed in the crankcase.

On Fig the main lines of the drawing show the position of the mechanism elements in front of the contact of the leash roller with the surface 115 of the rack, rearranged in a new position, dashed lines - the position of the rack 114 before switching and the position of the lead 112 at the end of the switch, with the piston position in NMT.

Arrow 121 shows the direction of movement of the piston in the period under consideration - when the angular position of the rotary type spool 76 changes.

AS is the amount of movement of the rail 114 when switching.

The slide valve 76 is switched by shifting the rod 114 to the value of AS, and when the piston moves to the BDC and in the area of the latter, the profile surfaces of the rack groove, acting on the lead roller, set the latter and, accordingly, the slide valve 76 to a new position.

Fig. 22 shows the switching of the control valve from the position corresponding to the setting of the low compression ratio (see Fig. 21) to the position of the high compression ratio, which in this case is achieved by exposing the roller to the leash of the surface 115 of the rail. Similarly, the surface 116 of the rack at its next rearrangement, the leash is rotated in the opposite direction described with the slide valve 76 set to a position corresponding to a low compression ratio.

Repositioning the rails 114 can be accomplished by a device similar to that shown in FIG. 20 by connecting the rails 114

earrings (connecting rods) with levers 106 fixed to a roller 107 common to all engine cylinders.

Inlet device

control oil to the cavity of the hydraulic cylinder 18 in the piston pin or outlet from it depending on the engine load level, shown in Figs. 23 ... 26 (embodiment), contains a piston integrated in the throne

0 2, under the piston pin and parallel to it, a distribution valve containing a rotary valve spool 122, provided with an internal cylindrical cavity 123 and connected to this cavity by a radial channel 124, telescopically connected to the valve spool 122 with a tubular shank, an oil receptacle 125, the cavity 126 of which is open to the end surface 127 of the connecting rod, sealed to the latter with the help of springs 128 and interfaced with the oil supply channel 129 in the connecting rod brought to the specified end surface 127, channels 130, 131, 132 connecting at the angular position of the spool 5 corresponding to the supply of control oil to the cavity 18, the radial channel 124 in the spool with a cavity 18 (see Fig. 25), and with the angular position of the spool corresponding to the removal of control oil from

0 cavity 18, connecting the latter by means of a groove 133, made on the side surface of the valve 122 with a drain channel 134 in the piston (see Fig. 26), a mechanism for changing the angular position of the gate 5 of the valve 122, containing the beam 88, mounted on the spool, rotary two-blade a switch 89 mounted on the control roller, completely similar to that shown in Figs. 12, 14, 15,

0, while the spool 122 in Fig. 23 is provided with the same axial and angular position locks as in Fig. 12.

In Fig. 23, the upper head of the connecting rod is provided with a bearing sleeve 135 pressed into the bore of the latter. The spool 122 may be integrated directly into the piston, as shown in FIG. 23, or mounted in a separate housing mounted on the piston, may provide 0 with a spool sleeve installed in said housing parts.

The diagram of the oil supply channels to the cavity 18 shown in Fig. 23 has, in comparison with Figs. 12, 13, a shorter length of the latter and fewer local resistances.

Fig. 27 and Fig. 28 (section no H-H) show an embodiment of a mechanism for changing the angular position (switching) of the spool 122, which allows the supply and removal of control oil from the cavity 18 in the device described above in Fig. 23.

The mechanism comprises a rocker arm 136 mounted on the spool 122 with cup-shaped blades and jet nozzles 26, 27 for controlling the position of the rocker blades directed to said cup-shaped blades and connected to the engine lubrication system or to an autonomous oil circuit through a control device for changing the compression ratio in depending on engine load level.

The rocker arm is equipped with rotation limiters 137, which are predominantly adjustable.

On Fig, 28 (section along H-H) shows the initial moment of switching the spool, with the main lines of the drawing showing the position of the rocker arm corresponding to a low compression ratio, the dashed line shows the position of the arms of the rocker arm after switching the spool to the position corresponding to a high compression ratio .

To accomplish this switch (high compression setting), control oil is supplied to the nozzle 27. A stream of fluid from the nozzle exerts hydrodynamic pressure on the right arm of the rocker arm and puts it into the position indicated by the dashed line. The reaction of the jet to the wall will be equal to the second impulse of force, i.e. P m and Q and p, where m and O are the mass and second fluid flow rate;

and - fluid flow rate;

p is the density of the liquid.

For example, a force impulse P at a control oil pressure of 6 atm and a nozzle diameter of 8 mm with a piston position in the BDC zone is 4 kgf, which is quite sufficient for switching the control valve.

Similarly, the control valve is switched from the position corresponding to the high compression ratio setting to the low compression position by supplying the control oil to the nozzle 26.

The supply of control oil to the nozzles 26.27 when the load changes at a certain level can be carried out by the device described above, shown in Fig. 11.

Obviously, the described mechanism can be used to switch the control valve in the device of Fig. 12.

If the conduit channels shown in Fig. 29 are used only to supply oil to the device cavity 18, a check valve can be integrated into the conrod to provide good access to it, as shown in the figure.

The check ball valve in FIG. 29 connects the ball 138 provided with a 5 guide 139.

If there is a device for changing the compression ratio of diesels without increasing the maximum cycle pressure, the following can be ensured: realizing high boost pressures while maintaining economy in partial modes and without impairing starting performance; exhaust gas toxicity reduction; extension of the range of used fuels.

5 For engines with quantitative control of gasoline - with spark ignition in partial modes, the weight of the intake fuel-air mixture in the cylinder is greatly reduced compared to

0 with full load, respectively, the pressure of the end of compression decreases, which, in accordance with the known thermodynamic dependences, greatly reduces the thermal efficiency and increases the specific consumption

5 fuel. The effect of controlling the compression ratio on the fuel consumption of ICE with spark ignition is higher than that of diesel engines and amounts to 13% in the lower region of partial loads.

0 The proposed device provides the ability to change the degree of compression without significant structural change of the piston, connecting rod or cylinder head, preserves their traditional

5 design, has good embeddability, relative simplicity of design, increased reliability and service life due to the absence of a pressure reducing valve and seals in comparison with PARSS. operating at high pressures, rapidly reducing the compression ratio, which prevents detonation combustion with increasing load.

The proposed device does not require

5, while adjusting the degree of compression of the axial displacements of the crankshaft with connecting rods, it has increased reliability and service life due to the significantly larger angle of elevation of the helical lines of the curved grooves and the exclusion of forced changes in the angular position of the eccentric during periods of high pressure in the engine cylinder, moreover, the main operation is more reliable 5 bearings of the crankshaft of the engine and piston bosses. The device has increased reliability and performance due to the organization of high and stable control efforts, providing the rotation of the eccentric, which measures the length of the connecting rod and the relative ease of control, because the rotation of the eccentric in the proposed device is carried out by a single-acting hydraulic cylinder.

The invention allows to increase the operability and durability of the proposed device and the high efficiency of its implementation due to the relative simplicity of the design and preservation of the traditional design of the cylinder head, piston and connecting rod of the engine.

The scope of the proposed device includes gasoline engines with spark ignition, supercharged diesel engines, multi-fuel engines.

Claims (5)

1. A device for varying the compression ratio of a reciprocating internal combustion engine, comprising a hollow piston pin fixed to the piston from axial movements with an eccentric mounted on it, mounted in the upper head of the connecting rod and equipped with a device for turning it, containing a screw pair that converts the translational movement of one of the elements rotational pairs of another, characterized in that, in order to increase the operability and resource of the device, to expand the possible field of its application, it contains a single-acting hydraulic cylinder built into the cavity of the piston pin, consisting of a piston of a hydraulic cylinder having a cup shape, a spring mounted between the piston pin retainer from axial movements and the hydraulic cylinder piston, a rod equipped with a shank fixed in the piston from angular and axial movements, and located in the middle part of the piston pin cavity with a head permanently mated to the internal cavity of the piston of the hydraulic cylinder within its stroke, a plug at the end of the piston pin mounted on the side opposite to the spring, and forming in the piston pin together with the bottom of the piston of the hydraulic cylinder the working cavity of the hydraulic cylinder, connected by one or more channels to a device that supplies control oil to or from the specified cavity of the hydraulic cylinder, depending on the engine load level, while the piston finger, hydraulic piston and stem head wives with elements made in the form of grooves and associated protrusions and engaging the piston of the hydraulic cylinder with the rod and with the piston pin within the stroke of the piston of the hydraulic cylinder, the grooves of one or both of these joints of the hydraulic piston are curved, in the latter case, with the opposite direction of the screw lines, and each of the curved grooves is made with a helix elevation angle greater than the friction angle in a helical pair formed by a groove and a protrusion associated with it. 2. Device pop. 1, characterized in that the device that supplies the control oil to the hydraulic cylinder cavity in the piston pin or diverts from it depending on the engine load level, contains an oil receiver that selects control oil from the oil supply channel into the connecting rod of the engine installed in the piston, in the bore under the piston pin, and connected by channels in the piston to the oil receiver, a distributor consisting of a torque hydraulic cylinder and a rotary distributor integrated in its housing o type associated with the blade of the torque cylinder, and two fixed nozzles 5 jet drives connected to the engine lubrication system or to an autonomous oil circuit through a control device for changing the compression ratio depending on the engine load level, at 0, the housing of the momentary hydraulic cylinder is made integrally with the plug in the end of the piston pin, which limits the cavity of the hydraulic cylinder in the piston pin, and is equipped with two channels in the cavity wall 5 of the hydraulic cylinder at its peripheral points on opposite sides of the blade, connected through channels in the piston to the nozzles of the jet drive, the spool is equipped with interconnected central and 0 radial channels, moreover, the central channel is constantly connected to the cavity of the hydraulic cylinder in the piston pin, and the radial channel, depending on the position of the blades of the torque cylinder, 5 is combined with either a channel connected to the cavity of the oil receiver at the position of the blades of the torque cylinder corresponding to the installation of a low compression ratio, or with the drain channel at the position 0 of the blade of the torque cylinder, which corresponds to a high compression ratio setting, and the blade of the hydraulic cylinder is equipped with a latch that locks it in each of the indicated positions. 5 3. The device according to claim 1, with the exception that the device for supplying control oil to the hydraulic cylinder cavity in the piston pin or for withdrawing from it depending on the engine load level contains in the throne of the piston, under the piston pin and parallel to it, a distribution valve containing a rotary valve, provided with an internal cylindrical cavity and a radial channel connected to this cavity, telescopically connected to the valve using a tubular shank installed in the bore of the latter, an oil receiver, the cavity of which is open to the end surface of the connecting rod, is sealed with the latter by means of springs and mating with an oil supply channel in the connecting rod brought to the specified end surface, channels in the plug installed in the end of the piston pin connected to the hydraulic cylinder cavity in the latter, and with the channel in the piston, combined with the angular position of the spool corresponding to the supply of control oil to the cavity of the hydraulic cylinder, with the radial channel in the spool, and with the angular position corresponding to the control oil from the cavity of the hydraulic cylinder, by means of a groove made on the side surface of the spool with a drain channel in the piston, a mechanism for changing the angular position of the spool, comprising a rocker arm with bowl-shaped blades and two stationary nozzles of the jet drive directed to said cup-shaped blades and connected to the engine lubrication system or to an autonomous oil circuit through a control device for changing the degree of compression depending on the level of load Igatel. 4. The device according to paragraphs 2 and 3, it is stipulated that the control device for changing the compression ratio depending on the engine load level contains a switching contact mechanically connected to the throttle actuator, valves with an electrically controlled actuator installed on pipelines for supplying oil to the nozzles of a jet actuator from the engine oil line or from an autonomous oil circuit, electric communication lines containing switching contact with an electrically controlled shut-off valve actuator s time switch. 5. The device according to claims 2 and 3, characterized in that the control device for changing the compression ratio depending on the engine load level comprises a switching contact mechanically connected to the rail of the high pressure fuel pump, shut-off valves with an electrically controlled actuator mounted on pipelines for supplying oil to the nozzles of the jet drive from the engine oil line or from an autonomous oil circuit, electrical lines connecting the switching contact with the electrically controlled shut-off valve actuator ANTONOV through the time switch. ; 10 34 R FIG. 2 R Fie.Z 4 0Ј / g4 F 32 I GG D .. 27 and 4B 2B (paa5 FIG. 6 O) CN CS CO r M $ And Ј9 60 6/62 63 4 L H L d / a Ј3 7U 7 # UDy1 (55 7/55 2. // N c And and p7 «| about Oh | 75 p "- i X7j oil Ј-Ј 82 1 FIG. fifteen 81 Fx Fig 0 89 Riga / 6 II .17. .S3 /// I / f ---- ft 76 86 87 78 76 ЈM ° / 87 86 Phage i & FIG. / ff FIG. L III 89  92 UZ CHOV 409 Vtf / FIG. twenty 60 in / .62 awmbiii air handling   t ig. FIG. 21 and with CN "Si with g-S2 ё SCH § SG; with 0 pj - OQ CQ J 0 B nn 27 FIG. 28