RU154844U1 - GAP COMPENSATOR FOR GAS DISTRIBUTION MECHANISM OF INTERNAL COMBUSTION ENGINE - Google Patents

Abstract

1. The gap compensator for the gas distribution mechanism of the internal combustion engine, containing a cup-shaped housing, the bottom of which is the outside of the working surface for contact with the cam of the gas distribution mechanism of the internal combustion engine, while a diaphragm with a base and a cylindrical protrusion is placed inside the housing, a movable hydraulic cylinder, a plunger with an oil supply channel and a spring, characterized in that inside the glass-shaped body under the wall of its working surface is placed tinuous magnet with the direction of the force of attraction to the engine cam timing internal sgoraniya.2. The gap compensator according to claim 1, characterized in that the permanent magnet is made in the form of a disk. The gap compensator according to claim 1, characterized in that the permanent magnet is made in the form of a rectangular ring in cross section. The gap compensator according to claim 1, characterized in that the permanent magnet is made in the form of a trapezoidal ring in cross section.

Description

The utility model relates to the field of engineering and may find application in internal combustion engines. In particular, in the framework of this application, the design of a hydraulic device for compensating gaps in the valve mechanism of an internal combustion engine (hydraulic compensator) is considered.

The dimensions of the parts of a working internal combustion engine increase due to heating. So that this does not lead to breakdowns, accelerated wear, deterioration of the characteristics of power units, thermal gaps are created between some parts at the design stage. When the motor warms up due to the expansion of parts, they are "selected" (absorbed). However, as parts wear out, their heating is not enough to absorb gaps, which adversely affects engine performance.

The thermal clearance in the valve drive mechanism directly affects the performance of the power unit. Since valve clearances are constantly changing due to wear of parts, as early as the beginning of the last century, a mechanism for regulating them with the help of conventional wrenches was introduced into the engine. This should be done regularly, which means that the complexity of maintenance increased and its cost increased. Hydrocompensators (GK) avoid these problems. They must completely absorb the gaps between the working surfaces of the camshaft and rockers, rocker arms, valves, rods, regardless of the temperature regime and the degree of wear of parts.

We will consider the device and principle of operation of the hydraulic compensator using the example of a hydraulic pusher installed in the cylinder head. The remaining types of hydraulic lifters, although they differ in design, but work on the same principle. The hydraulic pusher is a housing, inside of which a movable plunger pair with a ball valve is installed. The housing is movable relative to the guide seat made in the cylinder head. If the main assembly is mounted in the valve drive levers (in rockers or rockers), its movable part is only a plunger, the protruding part of which is made in the form of a ball bearing or support shoe.

The main part of the HA is a plunger pair. The gap between the sleeve and the plunger is only 5-8 microns, which ensures high tightness of the connection, while the mobility of the parts is maintained. In the lower part of the plunger, an opening for oil intake is made, which is closed by a spring-loaded check ball valve. Between the sleeve and the plunger, a sufficiently rigid return spring is installed.

When the camshaft cam is located on the rear side of the pusher body, there is no external compressive load and there is a gap (H) between the housing and the cam of the cold engine. The return spring pushes the plunger until this gap is “selected” - reduced to almost zero. At the same time, oil from the engine lubrication system through the ball valve and the bypass channel enters the internal cavity of the plunger and fills it.

As the shaft rotates, the cam begins to press on the body of the pusher and moves it down, blocking the oil channels - the engine lubrication system and the bypass channel. The ball valve closes, and the oil pressure under the plunger increases. Since the fluid is incompressible, the plunger pair begins to work as a rigid support, transmitting the cam force to the valve stem of the engine.

Although the clearance in the plunger pair is very small, a little oil is nevertheless squeezed back through the technological gap between the plunger and the sleeve, so the plunger lowers (“sags”) by 10-50 microns. The magnitude of the "drawdown" depends on the speed of rotation of the engine crankshaft. If they increase, by reducing the time of pressing the body of the hydraulic pusher, oil leakage from under the plunger is reduced.

The formation of a gap when the cam leaves the pusher is eliminated due to the action of the plunger return spring and the oil pressure in the engine lubrication system. Thus, the hydraulic compensator ensures the absence of gaps - due to the constant tight connection between the timing elements. Due to the heating of the engine, the length of the parts of the hydraulic compensator itself changes somewhat, but it automatically compensates for these changes.

The introduction of the HA allowed avoiding the adjustment of the valve mechanism clearances and making its operation more “soft”; reduce shock loads, that is, reduce wear on timing parts and eliminate increased engine noise; more accurately observe the duration of the gas distribution phases, which positively affects the safety of the engine, its power and fuel consumption.

Thus, a hydraulic device is known for compensating for gaps in the valve mechanism of an internal combustion engine, comprising a housing with an aperture, a diaphragm with a base and a cylindrical protrusion, a movable hydraulic cylinder, a plunger with an oil supply channel and a ball check valve, a spacer spring, and a diaphragm on the opposite side of the cylindrical protrusion an annular girdle tightly coupled with the annular groove of the housing, while the base of the diaphragm is connected with the annular girdle by a flexible conical or cylindrical an annular bridge (RU 2143565, F01L 1/25, publ. 27.12.1999). This decision was made as a prototype for all declared options.

With all its advantages, hydraulic lifters have disadvantages, and engines equipped with them have some operational features. One of the design flaws of simple hydraulic lifters is manifested in poor-quality operation of the cold engine in the first seconds of start-up, when there is no oil pressure in the lubrication system or it is minimal.

The inlet and outlet valves are heated to different temperatures, so the values of the thermal clearances required for them are different: for the inlet valves - 0.15-0.25 mm, and for the exhaust ones - 0.20-0.35 mm and even more. If these values are not met, the consequences can be very different:

- when the intake / exhaust valves are “tightened” (the gap is small or there is none at all), compression is reduced due to incomplete closing, which leads to loss of power, burnout of valve plates and their seats, and ignition of the fuel-air mixture in the intake / exhaust manifold ( when flame penetrates), the occurrence of glow ignition (due to overheating of the valve edges). If the valve is ajar, at any temperature the starting characteristics of the engine noticeably worsen;

- with increased gaps, increased shock loads arise, which, acting on the timing parts, reduce their service life. In addition, the filling of the cylinders with a fresh charge is deteriorating, and this is fraught with a decrease in torque and engine power.

The main reasons for the failure of the main circuit are the contamination of the engine oil channels and the wear of the working surfaces of the non-return valve and the plunger pair made with a high degree of accuracy. With an increase in the seating clearance in the plunger pair, oil leakage from the high-pressure chamber increases. The hydraulic compensator loses its “rigidity”, therefore, the efficiency of transmitting the cam force to the timing valve stem decreases. The same thing happens when the check valve of the high pressure chamber is worn. Malfunctions of the engine lubrication system slow down the filling of the hydraulic oil with oil and do not allow absorbing gaps in the timing.

This utility model is aimed at achieving a technical result consisting in increasing the operational life of the compensator by eliminating the influence of wear of the working surface in contact with the timing cam and by ensuring constant contact of this working surface with the timing cam.

The specified technical result is achieved in that in the gap compensator for the gas distribution mechanism of the internal combustion engine, containing a cup-shaped housing, the bottom of which is the outside of the working surface for contact with the cam of the gas distribution mechanism of the internal combustion engine, while a diaphragm with a base and a cylindrical a protrusion, a movable hydraulic cylinder, a plunger with an oil supply channel, and a spacer spring, inside a glass-shaped housing d the wall of its working surface contains a permanent magnet in the form of a disk or a permanent magnet in the form of a rectangular ring in cross section or a permanent magnet in the form of a trapezoidal ring in cross section to form the attractive force of the cup-shaped body to the cam of the gas distribution mechanism of the internal combustion engine.

These features are significant and are interconnected with the formation of a stable set of essential features sufficient to obtain the desired technical result.

The present utility model is illustrated by a specific example of execution, which, however, is not the only possible one, but clearly demonstrates the possibility of achieving the required technical result.

In FIG. 1 - presents the first example of the performance of the hydraulic compensator;

FIG. 2 - a second embodiment of the hydraulic compensator is presented;

FIG. 3 - presents a third example of the performance of the hydraulic compensator;

FIG. 4 illustrates the contact position of the working surface of the hydraulic compensator with the timing cam;

FIG. 5 is a magnetic field plot showing the presence of an attractive field in the area of the working surface of the hydraulic compensator;

FIG. 6 - scanning of magnetic fields in the area of the working surface of the hydraulic compensator.

This utility model considers the design of a clearance compensator for a gas distribution mechanism of an internal combustion engine. This compensator contains a cup-shaped body 1, the bottom of which is the outside of the working surface 2 for contact with the cam 3 of the gas distribution mechanism of an internal combustion engine (ICE). Inside the housing there is a diaphragm 4 with a base and a cylindrical protrusion, in which a movable hydraulic cylinder 5, a plunger with an oil supply channel, and a spring 6 are placed for pressing the housing to the cam.

This description of the design of the gap compensator for the timing of the internal combustion engine is given as an example. For the obviously useful model, the internal layout and design of the compensator itself are not important.

As you know, between the diaphragm and the plunger a fairly rigid return spring is installed. The purpose of this spring is to ensure that the housing contacts the timing cam. But the same spring has an effect on wear, as the pair “compensator housing-cam” operates in the sliding friction mode. To ensure reliable contact in this pair, the spring stiffness is chosen greater than what is actually necessary in order to maintain this contact in the presence of wear. In addition, despite the fact that for the engine timing, springs of approximately the same parameters are selected, there is still a difference in stiffness between them, which affects the uneven wear of the compensators. Reducing the stiffness of this spring would reduce the force in the sliding pair, leaving the spring with the function of damping and compensation of movements when transmitting forces from the cam through a compensator to the cylinder head valve. It would also allow increasing the efficiency of this pair and its durability in the mode of optimal functioning.

For this purpose, a permanent magnet 7 in the form of a disk (Fig. 1) or a permanent magnet 7 in the form of a rectangular ring in cross section (Fig. 2) or a permanent magnet 7 in the form of a trapezoidal ring is placed inside the glass-shaped form of the housing 1 under the wall of its working surface in cross section (Fig. 3) to form the attractive force F (Fig. 4) of a cup-shaped body to the cam 3 of the gas distribution mechanism of the internal combustion engine.

The tests, the results of which are shown in the form of graphic scans in FIG. 5 and 6 show that when a permanent magnet is used under the compensator’s working surface, a magnetic interaction of the housing with the cam occurs, the force F of which is directed towards the cam with attraction of the compensator housing. Thus, the compensator housing is constantly in contact with the cam, regardless of whether the engine is cold or already warmed up. Since constant contact in the pair “compensator housing - timing cam” is provided, the spring can be weakened and its effect on the degree of compression of the compensator can to be seriously reduced.

This utility model is industrially applicable, since it does not require a serious alteration of the design of the compensator. A permanent magnet in one form or another (for different models of hydraulic lifters) allows the formation of magnetic attraction as a force that replaces or partially compensates for the force of the preload spring.

Claims (4)

1. The gap compensator for the gas distribution mechanism of the internal combustion engine, containing a cup-shaped housing, the bottom of which is the outside of the working surface for contact with the cam of the gas distribution mechanism of the internal combustion engine, while a diaphragm with a base and a cylindrical protrusion is placed inside the housing, a movable hydraulic cylinder, a plunger with an oil supply channel and a spring, characterized in that inside the glass-shaped body under the wall of its working surface is placed tinuous magnet with the direction of the attractive force to the cam mechanism of the engine valve of the internal combustion. 2. The gap compensator according to claim 1, characterized in that the permanent magnet is made in the form of a disk. 3. The gap compensator according to claim 1, characterized in that the permanent magnet is made in the form of a rectangular ring in cross section. 4. The gap compensator according to claim 1, characterized in that the permanent magnet is made in the form of a trapezoidal ring in cross section.

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