RU129556U1 - TWO STROKE PISTON ENGINE - Google Patents

Abstract

A two-stroke piston engine containing a crankcase, a piston cylinder, a piston with a pusher, a fuel mixture supply, ignition and gas exhaust system, characterized in that the engine is equipped with a double-acting cam mechanism consisting of a power take-off shaft on which two are rigidly fixed with a gap for the pusher flywheel, on their inner side the same guiding cam grooves are formed, forming double-acting cams, the depth of the grooves forms the plane of the cams, differing by the working - - straight-line pushing, consisting of two parts - straight-line, turning into radially convex with decreasing radius to the top of the cam and returning - repeating their profiles, the pusher’s finger rolling along the planes, installed with its ends in the grooves and rotating in the pusher bearing, rigidly fixed to the piston, while from the lateral displacement the pusher is supported by two stops installed between the flywheels, rigidly fixed on the crankcase, tracks and limiters are made on them and on the adjacent walls of the pusher Olika slidably holding the plunger.

Description

The utility model relates to engine building, namely to reciprocating internal combustion engines used in automobiles, aircraft and other areas of mechanical engineering.

The closest solution to the claimed utility model is a two-stroke four-cylinder piston engine containing a piston cylinder, pistons with rods, a fuel mixture supply, ignition and exhaust gas system and a rotor ring fixedly mounted on the engine shaft and having external and internal tracks in contact with external and internal piston rollers (see RF patent No. 2103530, IPC F02B 75/22, F01B 9/06, publ. 1998)

The disadvantages of the known engine is:

- an overly complex bulky and ineffective mechanism for converting backward translational movements of the piston into rotational ones;

- the rods have a large mass, which creates additional load during backward translational movements of the piston;

- the rods have o-rings and a large number of bearings that can wear out quickly;

- the rotor ring has an obtuse track angle with respect to the movement of the rods at the top dead center and exhibit great resistance to the piston during the stroke;

- the design feature of this mechanism does not allow making the track angle sharper, which would certainly increase the engine's efficiency.

The purpose of this utility model is simplicity of design, increasing power per cylinder volume, reducing fuel consumption per horsepower, reliability, low engine weight and high efficiency

To achieve this goal in the proposed engine, comprising a crankcase, a piston cylinder, a piston with a pusher, a system for supplying the fuel mixture of ignition and exhaust gas, the engine is equipped with a double-acting cam mechanism that is movably connected by a finger to the pusher. The cam mechanism consists of a power take-off shaft on which two flywheels are rigidly fixed with a gap under the pusher. On their inner side, identical guide cam grooves are made mirror-like, forming each two double-acting cam. The pusher finger moves along the grooves, installed in them by its ends between the flywheels, so the cams work in pairs as one fist. The pusher is mounted on the finger between the flywheels from a lateral displacement relative to the center of the axis of rotation of the cam mechanism; it is movably held by two stops on opposite sides. The stops are installed between the flywheels and are rigidly attached to the engine crankcase. On them and on the walls of the pusher adjacent to them, guide tracks with limiters of the rollers in the form of bosses are made, along which the rollers holding the pusher roll, the length of the tracks is two times less than the stroke of the pusher. Stops are steel, their width corresponds to the width of the pusher. Steel rollers have a diameter sufficient to perform their function, their width is equal to the width of the pusher, are installed between the emphasis and the pusher at least one on two tracks.

Steel pushers of square section, a calibrated hole is made in the head at one end, into which a pusher pin is inserted through the roller bearing, and a threaded connection is made on the other end of the pusher for mounting the piston. The length of the pusher is sufficient so that the piston skirt does not hit the flywheels at bottom dead center, on the walls on the two sides of the diameter of the finger tracks are made for the rollers holding it.

The metal engine crankcase consists of two halves, the cam mechanism and stops are placed inside, the cylinder is attached from the outside.

The piston is made of light alloy, cylindrical, has a guide skirt in the lower part that regulates crankcase blowing, a head with grooves for compression rings, and a pusher mount in the center of the diameter.

The pusher finger is steel, cylindrical, the diameter corresponds to the width of the guide cam groove, the length is sufficient for operability and the finger does not rest against the ends of the groove, the pusher keeps it from possible distortions.

The flywheels are steel, round, a hole is made in the center of the circle for mounting on the power take-off shaft. The cams in them are made in pairs in the form of grooves of a parallelogram figure. With equal removal of all sides from the indicated hole, its two end walls are beveled along the rotation of the flywheels. The bevels are made unevenly radially convex with a decrease in the radius to the apex, the junction of the bevels with the adjacent working plane form the tops of the cams. The depth of the grooves forms a plane of the cams wide enough to hold in them and the operability of the finger of the pusher. The height of the grooves is equal to the thickness of the finger, while moving along them, the finger rolls along its planes along the planes of the groove, rotating in the pusher bearing. To avoid damage to the mechanism, the pusher finger and the guide grooves should have a minimum clearance. Cams have the shape of an irregular pyramid with planes on it: adjacent to the center of the pyramid - the main and opposite to it - return. The main plane is divided into working and pushing.

The working plane has a rectilinear surface from the base to the top. The pushing plane is strongly convex relative to the axial line passing between the tops of the cams and the center of the axis of the shaft, consists of two parts, from the base to the middle of the cam it is straight, made parallel to the working plane, then radially convex, the radius gradually decreases towards the top. A convex surface significantly increases the length of the plane from the base to the apex. The return plane repeats the profiles of the main planes and in any case returns the piston to the bottom dead center by turning the cam. The cams at the base around their axis of rotation have an invisible circle whose diameter is equal to the width of the base of the cam, meaning the main plane of the cam. The diameter allows you to not touch the pusher head over the power take-off shaft when passing a finger along it at bottom dead center. To reduce the diameter of this circle, it is preferable to make recesses in the shaft at the points of passage of the pusher head. The distance from the diameter of the circle to the top of the cam corresponds to the stroke of the piston in the cylinder.

The cam planes are constantly at an angle with respect to the stops. In this case, the angle of inclination of the planes varies depending on the position of the cam top to the stop and affects the speed and stroke of the piston relative to the degree of rotation of the cam, with sharpening the angle, the speed and stroke of the piston increases. The convex pushing plane regulates the piston stroke relative to the degree of rotation of the cam, controls the load on the cam mechanism. So from the bottom dead center to the middle of the stroke, it pushes the piston with acceleration. And then to the top dead center with deceleration by changing the angle of inclination of the plane of the cam to the stop.

During the working cycle, it is easier for the finger to shift the cam, since it is wedged into an acute angle between the stop and the plane of the cam at top dead center. In this case, the piston travels a greater distance than the rotation of the cam with a gradual deceleration to the bottom dead center. When the cam rotates 90 *, the piston passes from bottom dead center to top dead center.

The essence of the utility model is illustrated by drawings, where in Fig 1 - shows a longitudinal section of the engine; Fig.2 is a cross section of the engine; in Fig 3 - cam mechanism is a longitudinal section; in Fig 4 - cam mechanism - cross section; Fig. 5 - pusher; in Fig 6 - emphasis; Fig. 7 — flywheels — cross section; Fig. 8 — flywheels — longitudinal section.

A two stroke piston engine contains; split engine crankcase 1, cylinder 2, inlet window 3, exhaust window 4, piston 5, piston head 6, piston skirt 7, pusher 8, pusher roller track 9, pusher roller travel stop 10, roller 11, finger socket 12, finger bearing 13, pin 14, pusher stop 15, roller track on stop 16, roller travel stop 17, cam mechanism 18, flywheels 19, cam cam groove 20, cam working plane 21, straight plane 22, radial plane 23, cam top 24, cam base 25, return plane 26, cam radius ka 27, spark plug 28. Two-stroke piston engine operates as follows.

When the handwheels 19 are turned, the pushing straight planes of the cam 22 displace the pin 14 from an obtuse angle between the stop 15, into which the pusher 8 abuts against the plane of the cam 22 through the roller 11, the pin 14 rolls along the plane 22, raising the piston 5 to the top dead center. Since the plane of the cam 22 is convex relative to the base and top of the cam 24, it will very quickly become at an acute angle to the stop 15 and will accelerate the piston 5 to the middle of its stroke. The piston skirt 7 will open the inlet window 3 and the crankcase cavity will be filled with a combustible mixture. Next, the outlet window 4 of cylinder 2 will close the piston head 6, the pressure in the cylinder will begin to increase, compressing the combustible mixture, the plane of the cam 23 will smoothly transform into an obtuse angle, the piston 5 will slow down relative to the degree of rotation of the cam. At the top dead center, the top of the cam 24 passes the middle of the diameter of the finger 14, its working plane 21 will become at an acute positive angle to the stop 15, since the base of the cam 25 will be higher than the finger 14. The spark plug 28 will ignite the compressed fuel mixture and the working stroke will begin, where With gas pressure, piston 5 will go to bottom dead center. The finger 14 will begin to shift the top of the cam almost at a right angle relative to its stroke, abutting against the working plane 21. From the lateral displacement it will be held by the pusher 8, abutting against the stop 15 through roller 11 rolling along tracks 9 and 16. And since the greatest gas pressure cylinder when the piston 5 is at top dead center, while the top of the cam 24 is located at the greatest distance from the center of rotation of the cam mechanism 18 and has the greatest lever, it is here that the highest torque is achieved. As the piston 5 approaches the middle of the stroke, the cam lever decreases, the angle becomes dumber and the pressure on the piston decreases. At the end of the stroke, the outlet window 4 opens and the cylinder is purged with a new mixture, while the cam mechanism rotates by 50 *.

The advantages of the proposed engine:

Reducing fuel consumption per horsepower, increasing power per cylinder volume in one working cycle, low engine weight, reliable performance, simple design, high efficiency.

The proposed mechanism is technologically advanced, in it it is possible to betray the desired profiles to the planes, tilt angles relative to the movement of the pusher, change the number of cams and cylinders to achieve the desired result from the engine.

The proposed design will allow you to get the best result on small engines used in aviation, boats, motorcycles, as well as household appliances.

In order to reduce vibration from imbalance, it is recommended to equip the engine with two opposing cylinders operating simultaneously. The design makes it possible to produce a four-stroke version of the engine, but a two-stroke engine is preferable, since the highest torque is reached at top dead center, and decreases to the middle of the piston stroke, where the stroke ends, while the minimum volume of the crankcase voids provides a more complete filling of the cylinder with a combustible mixture. Thus, the goal is achieved.

Claims (1)

A two-stroke piston engine containing a crankcase, a piston cylinder, a piston with a pusher, a fuel mixture supply, ignition and gas exhaust system, characterized in that the engine is equipped with a double-acting cam mechanism consisting of a power take-off shaft on which two are rigidly fixed with a gap for the pusher flywheel, on their inner side the same guiding cam grooves are formed, forming double-acting cams, the depth of the grooves forms the plane of the cams, differing by the working - - straight-line pushing, consisting of two parts - straight-line, turning into radially convex with decreasing radius to the top of the cam and returning - repeating their profiles, the pusher’s finger rolling along the planes, installed with its ends in the grooves and rotating in the pusher bearing, rigidly fixed to the piston, while from the lateral displacement the pusher is supported by two stops installed between the flywheels, rigidly fixed on the crankcase, tracks and limiters are made on them and on the adjacent walls of the pusher Olika slidably holding the plunger.

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