LV13993B - Device for gas allocation adjustement in internal combustion engines - Google Patents

Abstract

The invention relates to motor engineering, specifically - to devices for adjustment of gas allocation cycles in internal combustion engines. More specifically, the invention relates to body of mechanisms for gas allocation and valve overlay, which separately for each valve change its intake, exhaust gas allocation cycles and valve overlay depending on engine load and speed. A device for gas allocation adjustment in internal combustion engines is offered. The device comprises tappet (1), which is fitted to move valve between its open and closed position; lobe (2), which is mounted on camshaft and moved by it, which has contact surface (3), which is suited for touching contact surface (4) of tappet (1) and for moving tappet (1) to create movement of valve; and device for turning tappet (1) in relation to movement plane of lobe (2) to a position where, as lobe (2) turns, contact surface (3) of lobe (2) and contact surface (4) of tappet (1) touch each other earlier and loosen later that in the original position. The device offered characterised in that: tappet (1) is equipped with roller (5), which forms contact surface (4) of tappet (1) and, as lobe (2) turns, rotates round its supposed longitudinal axis. Use of roller (5) on the upper surface of tappet (1) enables creating contact surface (4) with tappet (1), which provides the possibility gradually and at wide range to change valve opening and closing timing and duration, and simultaneously reduce frictional coefficient, by turning tappet in relation to movement plane of lobe.

Description

Technical field

The invention relates to an engine structure, in particular to devices for regulating the gas distribution phases of internal combustion engines, more particularly to a set of engine gas distribution and valve cover devices which individually change the inlet, exhaust gas distribution phase and valve cover depending on the engine. count.

Known state of the art

Combustion combustion in the engine cylinder is a rapid, complex chemical process in which the fuel-forming elements are oxidized by oxygen in the air. The reaction is of a multi-stage chain reaction nature. The faster the combustion occurs, the higher the temperature of the combustion products. The inlet and outlet valves are opened and closed before or after the piston change points for better cylinder filling and exhaust bleeding. In the high-speed engine, the intake valve opens upstream before the piston reaches the top change point (AMP). This provides a timely opening of the inlet duct at the start of the inlet stroke and increases the valve opening time. The inlet valve closes with a delay at the lowest exchange point (ZMP), which allows the inertia of the fuel mixture or airflow to be used, thereby improving cylinder filling and increasing engine power. The exhaust valve opens upstream at the end of the stroke. Pressure and temperature drop drastically, which significantly reduces exhaust work and protects the engine from overheating. The exhaust valve closes with a delay and the high speed valve corresponds to the maximum valve opening and closing angle values. Delayed shut-off of the exhaust valve contributes to better degassing of the combustion chamber. The flow time along the valve or crank shaft rotation angle corresponds to the inlet and outlet valve aperture. For some time both valves are in the open position (valve cover). However, the small flow area during the cover does not allow the exhaust gases to enter the inlet duct.

The exhaust inertia in the exhaust duct creates an injection that facilitates the intake of fresh combustion mixture and improves cylinder filling.

The function of the gas distribution mechanism is to inject combustion mixture or air into the engine cylinders in a timely manner and to remove combustion products. Depending on the number of cylinders of the engine, the number of liters or the type of application, the construction and the parameters of these mechanisms vary. Valve mechanisms are most commonly used in motorcycle engines, which provide full gas exchange at high speed, at which maximum power is achieved.

The inlet and outlet process are the result of the combined operation of the valves, their drive mechanism and the camshaft. The efficiency of the gas distribution mechanism for a multi-cylinder engine shall be evaluated by the filling factor and the uniformity of filling of the individual cylinders. The inlet and outlet valves are opened and closed before or after the piston changeover points for better cylinder filling and exhaust bleeding. The degree of opening and closing of the valves is determined by the angle of rotation of the crankshaft.

The maximum values of the valve lift and blowdown area, as well as the distribution phases, do not fully describe the valve throughput and the gas distribution mechanism as a whole. For this purpose, the parameter "time-out" is chosen, which describes both the valve throughput area and the throughput time.

Until recently, the valve opening and closing moments, the design of the camshaft cams, and the position of the mutual cams for specific engines were strictly determined by the designers. These gas distribution mechanism parameters are constant throughout the engine operating modes. The designs of these known gas distribution mechanisms did not provide for the possibility of adjusting the inlet and outlet valve opening phases in different engine operating modes and, consequently, providing optimum engine performance characteristics in all engine operating modes.

The intake and exhaust phases are different in different engine operating modes, and to achieve optimum performance it is necessary to "offset" these phases and to adjust the valve inlet, exhaust split, depending on engine load and speed. For example, at high engine speeds, faster valve opening and later valve closure are desirable. Conversely, when the engine is idling, keeping the valves in the open position will cause the engine's performance to deteriorate over time, so a shorter interval between opening and closing valves is desirable at low engine speeds.

Several types of gas distribution design are known which provide for automatic change of the valve inlet, exhaust gas distribution phase.

A gas distribution device is known (U.S. Pat. No. 5,231,960, "Aug. 3, 1993"), which includes sliders having a grip surface and one or two truncated edges. , as well as camshaft cams with a contact surface adapted for slider interaction. The slotted edges of the slider are intended to reduce the length of contact between the cam and the slider and respectively to shorten the time the valve is in the open position. In one embodiment of the known technical solution, the slider contact surface is further provided with a roller for reducing the coefficient of friction. In a known device, the slider is fixed to prevent it from rotating about its axis. A major disadvantage of the known device is that the valve inlet, exhaust gas distribution phases cannot be continuously adjusted to achieve optimum engine performance characteristics in all engine operating modes.

There is a known gas distributor which includes a camshaft with a plurality (two or three) cam groups of various shapes (e.g. VTEC system in Honda cars). Each cam group is designed to change the valve inlet, exhaust gas distribution phase at different engine speed ranges. The corresponding cam group is activated mechanically depending on engine speed. However, this device does not allow for continuous change of inlet and outlet valve opening phases, but only provides for two or three phases and accordingly does not allow for optimal engine performance characteristics in all engine operating modes.

There is known a gas distribution device comprising a cam camshaft, each of which is provided with a mechanism for changing the cam configuration, which in turn enables the valve inlet, exhaust gas distribution phases to be changed (WO 02/081872 Al "Variable Valve Timing System", publ. October 17, 2002). However, this gas distribution device has a complex design and high friction coefficients, which may indicate a lack of reliability and durability of the mechanism. In addition, the variable configuration of the cam design does not allow for stable control of the valve opening duration and, consequently, does not provide optimal engine performance characteristics in all engine operating modes.

The closest technical solution is the technical solution whereby the valve inlet, exhaust gas distribution phases are changed by rotating the slider around its vertical axis, changing the position of the camshaft cam and the slider contact point relative to the center of the slider contact surface. In one of the first such known technical solutions (US 26,63288, Variable timing cam follower, published Dec. 22, 1953), it is proposed to create a slider having a contact surface having two mutually perpendicular configurations - a circular and a rectangular one; provides it with rotation about its vertical axis, and means for holding the slider in two selected positions. The known design of the gas distribution mechanism o _t allows the valve to change the opening and closing times of the valves by 90 turns and provides for two variations of the valve inlet, exhaust gas distribution phase. A major disadvantage of the known gas distribution mechanism is the limited phase regulation range. Two phase variants are insufficient to provide optimum engine performance characteristics in all engine operating modes. In addition, the use of this type of known throttle valve valve thrust configuration results in camshaft cam shocks over the thruster and consequently early slider exit and thrust socket wear.

Later, several attempts were made to improve upon known technical solutions and to extend the range of phase regulation by creating a special shape of the slider and cam contact surface. For example, Parsons, etc. (EP 0292185, "Cam mechanisms", published Nov. 23, 1998) proposed to provide a circular concave slider grip surface and a circular convex cam contact surface profile, the slider being provided with a gear which is connected to a rack which allows the slider to be rotated. around your axis for a certain number of degrees. Rotating the slider by a few degrees allows you to change the position of the grip point (relative to the center of the slider contact surface) where the camshaft cam contacts the slider. Thus, rotation of the slider in the known device enables the opening time of the valves to be controlled. The main disadvantage of the known gas distribution mechanism is that the particular thrust grip configuration prevents reaching the narrow throttle phase and consequently reducing the idle speed of the engine to its optimum number, since the cam engages and leaves the thrust grip surface more than the camshaft revolution. Likewise, the known design of the gas distribution mechanism prevents high engine torque at low engine speeds.

Also known is a gas distribution device (EP 0894185, "Valve timing system", publ.

18.02.2004) comprising a camshaft with cam-shaped outer surface and sliders having a V-shaped recess facing the camshaft cam, the sliders being connected to a connecting rod the engine speed or engine operating mode can be rotated about a certain degree around its axis. As the sliders are rotated, the outer surface of the V-cam does not coincide with the V-groove on the slider surface, but faces the oblique plane of the V-groove at a higher point on the slider surface, which causes the camshaft cam to contact the slider earlier , than is the case when the outer V-shaped cam surface coincides with the V-shaped recess in the slider surface. In this way the valve can be opened earlier and later closed. However, due to the use of a V-shaped cam and slider surface profile, the cam and slider contact occurs only in a small area at some surface areas, causing rapid, uneven cam and slider working surface wear and, consequently, poor gas distribution mechanism reliability and durability. In addition, the known throttle grip configuration of the gas distributor also prevents reaching the narrow throttle phase and reducing the engine idle speed to the optimum number, since the cam engages and leaves the thrust grip beyond the ¹ A revolution of the camshaft.

A gas distribution device (WO 2007 / 099287A1 "Variable engine valve actuation system", published 07.09.2007) is known which comprises a camshaft with two different configuration bumps and a slider with two cams on the contact surface. Rotating the slider around its vertical axis allows the first camshaft tab to engage one slider contact tab or the second camshaft tab to engage the second slider contact tab, resulting in a known gas distributor to change the opening and closing times of the valves, variations in the gas distribution phase. However, the known gas distribution device does not allow to achieve narrow torque gas distribution phases and has a limited number of gas distribution phases.

DETAILED DESCRIPTION OF THE INVENTION

The object of the invention is to eliminate the drawbacks of analogs, including the creation of a relatively simple gas distribution and valve cover system, which allows fluidly changing inlet and exhaust gas distribution valve and valve cover without requiring the use of many complex mechanical components, and provides a wide gas exchange phase change range .

The stated purpose is achieved by the use of a roller mounted on the upper surface of the valve slider and by rotation of the valve slider relative to the plane of motion of the cam. The use of a roller mounted on the upper surface of the valve slider enables the adhesive surface to be created with a valve slider that allows fluidly varying, wide range, valve opening and closing time and duration while reducing the friction coefficient by rotating the valve slider relative to the cam plane.

The essence of the invention and its implementation are further explained with reference to the drawings and examples.

a brief description of the drawings

Fig. 1a is a schematic top view of one exemplary embodiment of the present invention.

Fig. 1b shows a schematic diagram of one embodiment of the invention, a cross-section of the front.

Fig. 1c shows a schematic diagram of one embodiment of the invention, a left side view.

Fig .ld shows a schematic, cross-sectional view of an alternative embodiment of the invention.

Figure 1 shows a schematic diagram of another embodiment of an alternative embodiment of the invention.

Fig. 2 shows the (gradual) change in the intake and exhaust gas distribution phases during engine operation as a function of engine load and speed: a - engine idling, b - engine operating at high speed, c - engine operating at high speed.

The device for controlling the gas distribution phases of an internal combustion engine shown in Figsla to Fig.lc includes:

a valve slider 1 adapted to move the valve between an open and a closed position;

a cam 2 (preferably with a simple-to-flat contact surface contour) disposed on the camshaft and having a contact surface 3 adapted for gripping with the grip surface 4 of the valve pusher 1 and the movement of the valve pusher 1 to move the valve and a means for rotating the valve relative to the plane of motion of the cam 2 in a position where the contact surface 3 of the cam 2 and the gripping surface 4 of the valve pusher 4 engage with each other more rapidly and release each other laterally than in the starting position, the valve pusher 1 being provided with a roller 5, preferably cylindrical, forming a grip surface 4 of a valve pusher 1. The roller 5 is mounted on the upper surface of the valve pusher 1, preferably in a socket 6. The accompanying drawings show an embodiment of roller 5 in which the axis of symmetry of the roller , however, the skilled person has a obviously, the pet 5 may be mounted asymmetrically with respect to the axis of symmetry of the valve pusher 1, i.e. not at the center of the valve pusher 1.

In the embodiment of the invention shown in Fig. Ld to simplify replacement of the valve pusher part 1 that is most subject to wear, the pivot 5 is mounted on the insert 7, whereby the valve pusher 1 is mounted on the socket 8. The rotation of the insert 7 . In the exemplary embodiment of the invention shown in Fig .ld, the insert 7 is designed in the form of a gear type insert, but the means for rotating the insert 7 may be in the form of a rack, a swivel arm or any other known means. In case of abrasion of the contact surface 4 of the valve pusher 1, the insert 7 can be replaced without removing the camshaft. In the proposed embodiment, the valve adjustment washer 9 can be mounted under the insert 7 by means of mechanical sliders for adjusting the clearance between the valve slider 1 and the lug 2.

In the embodiment of the invention shown in Fig.ld, to improve the rotation of the roller 5 and to reduce the coefficient of friction, it is proposed to additionally install roller 5 'and roller 5 below the level of roller 5, wherein the longitudinal axis of symmetry of all three rollers is parallel but their lateral surfaces are in contact.

It will be obvious to one skilled in the art that, depending on the design of the gas distribution mechanism, the roller 5 (including roller 5 'and roller 5) may also be incorporated in the valve traverse 10 (Fig .le).

Any known means for rotating the slider around its vertical axis, such as a worm gear for a pivoting lever coupled to the slider, can be used as a cutting tool for the valve slider 1 (Figs. 1a to Fig. Ld). To illustrate the operation of the gas distribution mechanism, a gear or gear sector 11 is mounted on a valve pusher cutting means 11 disposed on each inlet and outlet valve actuator 1, a slider rack 12 separately associated with each gear or gear sector 11 and adapted to provide a valve actuator with respect to the plane of movement of the cam 2 and at least one hydraulic ram of the rack 13.

It will be apparent to one of ordinary skill in the art that, with the present invention, the design of gas distribution and valve cover units may not utilize rack and pinion gears, but the inlet and outlet valve sliders 1 incorporating electronic inputs and outputs 14 in the desired direction, using data from the electronic control unit 14 (Fig.la), thus automatically changing the inlet and outlet phases and valve cover depending on the engine speed and load applied to it. The same result can be achieved by mounting the electronic control unit 14 on a hydraulic unit which, by means of hydraulics, rotates the cylindrical sliders in the required direction.

As the camshaft rotates, the cam 2 is in contact with the roller 5 mounted on the valve slider 1. When the engine is idling, the roller 5 is in the position shown in Fig.2a. In this case, the path of the cam 2 along the grip surface 4 of the valve pusher 1 and, accordingly, the opening and closing time of the valve is determined by the diameter of the roller 5. The larger the diameter of the roller 5, the sooner the contact of the cam 2 with the grip surface 4 of the valve pusher 1 and the later the exit of the cam 2 from the grip surface 4.

As the valve pusher 1 turns (Fig. 2b and Fig. 2c), the path length of the cam 2 along the grip surface 4 and thus the opening and closing time of the valve changes, the valve opens earlier and closes later than the initial position of the roller 5. Such a change in the path length of the cam 2 along the grip surface 4 of the valve pusher 1 allows the time and duration of valve opening and closing to be controlled, which in turn allows the gas distribution phases to be adjusted. Using the roller 5 as the grip surface 4 of the valve pusher 1 allows the engine idle speed to be reduced, since the configuration of the grip surface of such a valve pusher ensures that the valve opens and closes more than once per camshaft revolution. In addition, the use of the roller 5 as the grip surface 4 of the valve pusher 1 allows a smooth running of the cam 2 along the grip surface 4 and avoids the disadvantages of some technical solutions, such as those described in US 2663288 and EP 0292185.

A roller 5 having a length greater than its diameter is used to implement this invention. The length of the roller 5 is directly proportional to the size of the phase adjustment range (the smaller the length of the roller 5, the narrower the gas adjustment phase range). The same statement holds true for the camshaft cam 2 thickness - the smaller the cam 2 thickness, the narrower the gas regulating phase range. The thickness of the cam 2 must be consistent with the length of the roller 5, but its absolute size and ratio to the dimensions of the roller 5 are calculated by known methods depending on the required cylinder fill factor, valve cover time and slit required, and other engine specifications and manufacturer specific goals. The minimum effective length of the roller 5 may be calculated using the formula h = kj2 + d42, where h is the minimum effective length of the roller 5, k is the thickness of the cam 2 and d is the diameter of the roller 5.

Fig. 1a communicates with the gears or gears embedded in the slider 1 of the inlet and outlet valves 11, and the hydraulic mechanisms 13 of the rack 12 receiving operating information from the electronic control unit 14 are located at the end thereof. 13 moves the slider rack 12, which in turn rotates the valve sliders 1 in the required direction, which changes the swing of the rollers 5, which automatically changes the inlet and outlet valve phases and valve cover.

Fig.2 shows the variation of the inlet and exhaust gas distribution phases of the proposed device during engine operation as a function of engine load and speed, where: a - engine idling, b - engine low speed, c - engine change , at high engine speeds.

Fig. 2b, when the engine is running at low speed, information from the electronic gear unit 14 gearwheel hydraulic mechanisms 13 causes the slider gearwheels 12, which are in constant contact with the gears in the valve sliders 1, to be moved and rotated by turning the rollers 5. the roller path 5 increases by changing the inlet, outlet and valve cover phases.

Fig. 2c, when the engine is operating at high speed, further rotates the valve pusher 1 and the camshaft cam 2 to change the path, increasing the inlet, outlet and valve cover phases. As the engine speed drops, the camshaft cam 2 and valve pusher 1 return to their starting position shown in Fig.2a, shortening the inlet, outlet, and valve cover phases.

Changing the automatic inlet and outlet phases for each valve individually and changing the valve cover may be used regardless of the number of valves per cylinder.

By means of the present invention, it is possible to create a mechanical, hydraulic and / or electronic device for gas distribution and valve cover, which automatically changes the inlet and exhaust gas distribution phase and valve cover for each valve depending on the load applied to the engine and the speed.

Claims (5)

Claims 1. A device for controlling the gas distribution phases of an internal combustion engine, comprising: - a valve slider (1) adapted to move the valve between open and closed positions; - a tab (2) disposed on a camshaft having a contact surface (3) adapted for engagement with the grip surface (4) of the valve pusher (1) so that movement of the valve pusher (1) ensures movement of the valve, and - means for rotating the valve pusher (1) relative to the plane of motion of the cam (2) to a position where the contact surface (3) of the cam (2) and the grip surface (4) of the valve pusher (1) engage with each other earlier; and released later than in the starting position, characterized in that the valve pusher (1) is provided with a roller (5) which forms the grip surface (4) of the valve pusher (1) and pivots about its pivot when rotated. imaginary elongate. Device for controlling the gas distribution phases of an internal combustion engine according to claim 1, characterized in that the roller (5) is mounted in a socket (6) on the upper surface of the valve pusher (1). A device for regulating the gas distribution phases of an internal combustion engine according to claim 1 or 2, characterized in that the roller (5) is mounted on a sleeve (7) which in turn is inserted into the seat (8) of the valve pusher (1). A device for controlling the gas distribution phases of an internal combustion engine according to any one of claims 1 to 3, characterized in that the roller (5) is mounted in the valve traverse (10). Device for controlling the gas distribution phases of an internal combustion engine according to any one of claims 1 to 4, characterized in that a roller (5 ') is additionally inserted in the valve slider (1) or in the insert (7) below the level of the roller (5). and the roller (5) such that the longitudinal axis of symmetry of all three rollers is parallel but their lateral surfaces are in contact.