DE1776054A1 - Piston engine - Google Patents

Description

Hotorenfabrlk Hat ζ G.m.b.H. 9.9.1968

Ruhstorf b / Passau H 27

Piston engine

The invention relates to a piston machine with at least two cylinders and longitudinally movable therein. chen pistons and a common, central output shaft. "

With piston machines of this type, especially internal combustion engines, the connection between the piston and vielle is made in the usual way by a connecting rod. However, this arrangement has a particularly complex structure and a large amount of space nor the serious disadvantage, dac; j the additional Fasteners represent a very big hate that causes considerable vibrations of always j variable direction during operation. These vibrations or Vibrations were found to be very annoying and, moreover, cause excessive wear on the machine elements and an excessive burden on the bearings.

It is the object of the present invention to eliminate the disadvantages mentioned of the previous arrangements. Eliminate and <: ine vibrational're.Le, crowded and without Lagoriiber-Jar; Lung to create a Ko! hon machine. This Auf- / jubo is invented by go Lust, dans rlLo Üylin-

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which are diametrically opposed in pairs in relation to the shaft axis are arranged and that for the transmission of motion between the piston and output shaft on the latter at least one pair of crochets with the same cams diametrically opposite with respect to the shaft axis are provided is. Each of the cams can act on the assigned piston directly or via a roller.

In a particular embodiment of the invention at least one teder provided, the center of which lies approximately in the shaft axis and each end of which is at one of the engages diametrically opposite piston and seeks to move the same against the shaft axis. This feather can be adapted in their size and power without difficulty to the given operating conditions.

When using the subject matter of the invention on two-stroke internal combustion engines The only task of the spring is to support the piston on the cam when the machine is at a standstill to secure and to establish when starting, so that it does not have to be overly strong. In four-stroke internal combustion engines on the other hand, the spring still has to be between the force-fit support during a certain operating phase Manage the piston and cam, so that in this case it will have to be interpreted stronger.

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According to another feature of the invention, at least one elastic connecting means can be provided to secure and / or produce the force-fit support between the piston and the cam, which is connected with one end to the piston and with the other end to a member that is movable in opposite cycles relative to the piston is. This member is expediently designed as a spring plate moved by a compensating spring. _{J3ei piston Λ designed} according to the invention

According to a further embodiment, it is a machine with two pairs of pistons offset perpendicular to one another Invention particularly advantageous to make the arrangement such that the connecting means with one end engages one piston of the first pair, is deflected on the output shaft «and with the other end with one Piston of the second pair is connected. In all cases it is preferable to have the lanyard made up as a ribbon elastic material, preferably spring steel sheet . '

For piston engines that are used as two-stroke internal combustion engines are designed and provided with a conveyor for scavenging air, it is according to a further feature the invention advantageous to make the arrangement such that a with the movement of the piston its position changing part of the spring or the belt drives the conveyor. Preferably one becomes one "om the moving part driven shaft and one by

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the same "movable elastic membrane for this purpose use. In this way, the purge air charging device create with a minimum of structural elements.

Another feature of the invention provides that additional cams are provided on the drive shaft Serve for control purposes, e.g. to control valves, injection nozzles or the like .. This also reduces the control elements to a minimum, which is the basis for Forms a very compact small piston machine with a particularly high power-to-weight ratio.

The following description is based on drawings some embodiments of the invention explained. Show it :

Pig. 1-3 the first embodiment in

View, side elevation or top view,

Pig. 4 + 5 two other designs, and

6-8 a further embodiment in different, partially sectioned views.

That in Pig. 1-3 shown first embodiment shows a piston engine as a two-cylinder Two-stroke internal combustion engine of known mode of operation is trained. In a cylinder block 1, two diametrically opposed cylinder bores 1a, 1b are incorporated.

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beltet, while an interior 1c is provided in the Mitbe. A drive shaft 2 is axially supported by means of bearings 3, 4 and equipped with a coupling slot 2a for driving any unit, not shown. Sealing means are denoted by 5 and 6, which seal off the interior 1c to the outside. Cooling fins 1d, 1e are attached to the circumference of the cylinder, while a cylinder head 7a, 7b is fastened to the block at each end. A commercially available spark plug 8a, 8b is fastened in each cylinder head. A cover 11 carrying the carburetor 9 and the intake flap Io is fastened to one narrow side If of the block 1 by means of a few screws known electromagnetic ignition distributor driven, some of the vanes acting as a cooling air fan are at whose circumference additionally formed 13 for cooling the parts 1d, 1e. the stationary or fixed part 12a of the distributor is at block 1 loading (solidifies. the Antriebnübarleitung of shaft 2 on the rotating part 12 can be done for example by means of a wedge spring 14.

The scavenging slots 1sa, 1sb are still in the cylinder block 1 Provided in the area of the cylinder ta, 1b that the flushing flow pass through the cylinder in a known manner. In each cylinder, a piston 14a, 14b is arranged, which in Direction to the center of the axis is movable back and forth. The pre

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"connection between cage 14 and output shaft 2 happens here, however, not in the well-known way via a connecting rod, but is in the following arrangement executed:

In each piston 14a, 14b there is a roller pin 15a, 15b stored transversely, not on dome with interposition needle bearing shown is a roller 16a, 16b rotatable ^. With these roles there is a nooke 2na, 2nb which is attached to the shaft 2 in engagement. The cams can be integral with the shaft or but manufactured separately and only then firmly connected to the shaft 2. The cams 2na, 2nb are diametrically opposed opposite, so that they work alternately with the rollers I6a, i6b of the pistons when the shaft 2 rotates.

A hairpin-like shaped return spring 17 is arranged in the interior w 1c such that its curvature provided with corresponding ends 17a, 17b respectively, the roller pins 15a, 15b engage around. The spring leg 17as of this spring forms a central, multiple loop 17ac near the shaft 2, then goes with the leg 17az across the interior 1c and unites, at 17d with the other spring part 17bz, which is in the same way but on the other Side of the cams 2na, 2nb is arranged. At the point 17d, the spring 17 is with

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an elastic membrane 18 or the like via a rivet 19. tied together.

The described arrangement of the spring 17 ensures that when the piston 14 moves outwards, i.e. in the upper dead center position (TDC), the legs 17as> 17bs are stretched so that the central loops 17az, 17bz are against the shaft 2, so move in the direction of arrow A. The point 17d makes a movement in the same direction * in the direction of the arrow B, so that the membrane 18 is bent outwards (Pig. 2 and 3). When the pistons 14 move inwards, i.e. into the lower dead center position (BDC), the legs 17as, 17bs contract due to the elasticity of the pedals, so that the pedestal parts 17ac, 17bc, 17d now move in the opposite direction (against arrows A, B ) carry out. The membrane 18 is pulled inwards again in this phase. This movement of the diaphragm 18, which runs in a cycle with the piston movement, is used for the pumping effect, so that the parts 17d and 18 act as a charging device or charging fan undergoes good compression. (In the case of other designs, instead of the membrane 18, a delivery piston or the like could also be connected to the pedestal part 17d for the purpose just explained,)

The mode of operation of the arrangement described is the same

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those of the well-known two-stroke engines with positive ignition, so that the relevant puncture explanations of the two work cycles are not discussed in more detail target. The difference is that both pistons run in the same cycle, i.e. both at the same time in TDC or go in UT. It is also different that in the present arrangement the movement of the pistons 14a »14b after OT is only forced via cams 2na, 2nb, wähfe When these pistons move after BDC, the rotary movement of the shaft is caused by the pistons via the same cams 2 is enforced. This is the force-fit engagement of elements 14a, 14b on the one hand and of elements 2na, 2nb on the other hand at each point in time of the two bars (up to a certain speed), namely by the on each piston from the cam or from the associated Pressure or counterpressure acting on the combustion chamber.

A perfect drive connection is in other words th is guaranteed when the inertia forces acting on the piston are equal to or smaller than the. pressure acting on the piston in the combustion chamber. In the example shown, it is assumed that the piston elevation curve, which results from the roller diameter, the tip circle of the cam and the curvature of the leading and trailing edge as well as the base circle of the cam, represents a pure sine curve. It will therefore be a flawless one Drive connection guaranteed as long as the IOrmel

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ο
P = η · «. r. sin OC

is complied with, where means

P = pressure on the piston,

η = double the speed of the output shaft, Ci = double the angular speed of the output shaft, r = half the height of the nook,

OC = double the angle of rotation of the output shaft

When moving up / down (from UT to Oi ') until half stroke, i.e. at least as long as the flushing slots 1sa, Isb are open, the piston 14a, Hb accelerates. Already when the piston traverses this rinsing braid a counterpressure builds up in each cylinder 1a, 1b, the pressing of the piston 14a, 14b or no roller 16a, 16b increased to the associated jib 2na, 2nb. As soon half the lifting height exceeded Lυt, although the Piston movement delayed, the back pressure at this time- i point, however, already eats greater than the deceleration forces, sodaas also in this phase of upward movement the force closure is always maintained. The greatest deceleration forces act on the piston in TDC. To this However, the opposing forces are also from the point in time Cylinder at the largest.

U ¹ Ur the downward movement of the pistons (from TDC to BDC), the same applies analogously, what is just about the upward movement

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gung was said. As a result, there is always a force connection between the pistons even during the downward movement and curl present.

As just explained, are the forces acting on each piston in the illustrated embodiment and counterforces are coordinated in such a way that this alone always creates a non-positive contact between the pistons and Focke is ensured up to a critical speed. The return spring 17 is so while the engine is running not necessary per se. It only serves to start the stationary internal combustion engine help in those cases where both pistons happened to have stopped at TDC. In these cases the When the spring moves the nook when starting, move the two pistons to BDC to close the engagement between the parts guarantee. Here, the spring only needs the friction between piston and cylinder as well as the relatively small Overcome the flushing pressure in space 1c and possibly the weight of the piston if the internal combustion engine is in this way is arranged that the piston axes are perpendicular. The spring forces necessary for this are very great low, so that the spring 17 only needs a weak leg.

For designs where the return spring does not have to be used to drive a purge air charging device, the

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Training this return spring also in a simpler way as shown in Fig.1, possible as the execution "example according to Figure 4 shows. Here, on each side of the cam 2na, 2nb, there is such a simple spring 117 arranged. In this way, not only the return of the piston 14 is ensured, but also through the Attack of the two springs 117 symmetrically to the cylinder axis on a single roller bolt. 15a and 15b of the respective piston in its correct running position to the Squat 2na, 2nb held.

It should also be mentioned that instead of a return spring, each piston also has at least one end a steel band 217 according to Fig. 5 could be connected, the other end of which is anchored to a part that moves in the opposite cycle to the piston, see above. at a stationary rotating roller 218 which rotates in the direction of arrow G under the action of a spiral spring 219 will. This causes the band 217 to move as the piston moves 14 in. UT on roller 218 under the action of spring 219 rolled up and unrolled again from the roller 218 when the piston moves in TDC against the spring 219. (Instead of A steel band would also be a steel wire or chain for this type of retrieval of the piston applicable for the same purpose.).

The execution of the Nobel Games after Fi ^ ;. 1 - 5 could be in

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similar shape as a single-cylinder internal combustion engine be carried out if, for example, the piston 14b does not correspond to the pressure in a combustion chamber (1b) is exposed, but only under the action of a correspondingly strong spring with its roller 16b against the assigned nooke 2nb or 2na is pressed. This piston 14b would then only have the task of a return member to be fulfilled for the working piston 14a *

The embodiment according to Pig. 6-8 shows a four-cylinder four-stroke internal combustion engine operating according to a known principle with external ignition, in which - in contrast to the example according to FIGS. 1-3 - two at 90 ° to each other offset piston pairs are provided. The connecting rodless power transmission between the output shaft and piston is the same here as with the first type, so that the explanations in this regard are not discussed in more detail target. It is only to be mentioned in general that in the design according to Fig. 6-8 the parts that follow the 1-3, in the example now dealt with are also identified by the same reference numbers, but increased by 300.

In the present example, too, the elements are designed in such a way that the cam elevation curve is a sinusoid represents. As with high-speed four-stroke engines on the one hand the inertia forces are considerable and, on the other hand, which are

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the piston acting pressures "or, counter pressures from the Cylinder particularly low in "certain operating phases" or even slightly negative (suction stroke) is here An inevitable Rüclholvorkehrung for each piston to ensure the engagement between the basket and the cam necessary. This retrieval is designed here in such a way that a spring steel band is attached to the piston 314a of one pair 317a attacks, which is deflected on shaft 302 at 3O2u and is attached to the piston 314c of the other pair. | A second band 317b is similarly between pistons 314b and 314d are provided. Since the two by a band connected pistons run in the opposite cycle, the belt length (assuming D = d) always remains the same.

In cases where, for structural reasons, the diameter D of the shaft part must be kept larger than the diameter d, a compensation in the resulting movement of the pistons3i4a and3i4 "C can thereby be created that with the same base and tip circle the rising and / or falling edges of the cams 302na, 302 nb slightly to be changed.

Instead of the Pederstahlband, a spring steel wire could also be used or a chain or the like. .be used. Besides that two such connecting elements could be suspended symmetrically on a single piston, if this is to improve the parallel guidance of the KoI-

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bens or its roller to the nooke should be required.

On the drive shaft 302 are 3O2n next to the cam still two further control cams 302i and 302e attached, which the inlet valves 320a, 320b, 320c, 320d and the Outlet valves 321a, 321b, 321c, 321d via intermediate, control known transmission elements.

For engines with self-ignition (diesel engines), a third control cam could be used, e.g. for the injection nozzles be provided on the shaft 302.

In the arrangement shown, there is only one control cam for a specific group of control parts used so that the firing order is a, b, c, d. When using several control cams for a group, e.g. for inlet valves, but the firing order can easily be changed in any way.

In all of the embodiments of the invention, no lateral and no constantly changing ones act on the output shaft Moments so that feared vibrations hardly occur in the drive. Also the transition forces between The piston and nooke are always the same on both sides of the shaft, are always perpendicular to the nooke and change on both sides in the same cycle, so that no or minimal bending forces act on the shaft.

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ken. This shaft can therefore be made very weak and supported with only small main bearings. Furthermore the number and shape of the drive cams on the shaft can be adapted to the desired transmission ratio be, so instead of the reduction 1: 2 in the examples shown also a reduction 1: 3 or 1: 4 can be achieved.

For the execution of the piston size according to the invention f

elements required for the machine (piston, shaft, cam, yentile, etc.) have the well-known shape, so that they can be used with the previous manufacturing means or processes can also be carried out and produced economically in mass production.

As a result of the elimination of connecting rods in the piston gear, the overall height of the machine is also considerable shortened and created a compact or compact piston engine design.

The designs shown are only possible exemplary embodiments, without the invention being restricted thereto. Other forms of implementation of the subject matter of the invention would also be possible, e.g. a piston engine with two or several piston stars lying one behind the other. Finally, the invention can also be used in other piston machines.

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Claims (13)

Claims: '. 1, piston machine with at least two cylinders and longitudinally movable pistons therein and a common, central output shaft, characterized in that the cylinders are arranged in pairs diametrically opposite one another with respect to the shaft axis and that for the transmission of motion between KoI-. ben and output shaft on the latter at least one pair of cams is provided with the same cams diametrically opposite with respect to the shaft axis . ■■■■ '■. 2. Piston machine according to claim 1, characterized in that each of the cams is located directly on it engages associated piston. * 3. Piston machine according to claim 1, characterized in that each of the cams engages a roller, which is mounted on the associated piston. 4. Piston machine according to claim 1, characterized in that that each piston is secured against rotary movement around the cylinder axis by means of guide means. 5. Piston machine according to AnsprWti 1, characterized 009846/0385 net that at least one spring is provided, whose center lies approximately in the shaft axis and each of which ends at one of the diametrically opposite ones Piston attacks as well as "strives to move the same against the shaft axis. 6. Piston machine according to claim 5, characterized in that that the spring as a hairpin-shaped which surrounds the output shaft with its center Clock spring is formed. 7. Piston engine according to claim 5, which is used as a two-stroke internal combustion engine is designed and provided with a conveying device for scavenging air, characterized in that a with the movement of the piston its position changing part of the spring drives the conveyor. 8. Piston machine according to claim 7, characterized by one driven by the movable part of the spring Plunger and an elastic membrane that can be moved through the same. 9. Piston machine according to one of the preceding claims, characterized in that additional cams are provided on the output shaft, which serve for control purposes, e.g. to control valves 009846/0 385 valves, injection nozzles or the like. 10. Piston machine according to claim 1, characterized in that that at least one elastic connecting means is provided, which with one end at the piston and at the other end at a relative to the piston movable in the opposite cycle Link is connected. 11. Piston engine according to claim 10, characterized in that the member as one by a compensating spring moving spring plate or rotating roller is formed. 12. Piston machine according to claim 1o, with two pairs of pistons offset perpendicular to one another, characterized characterized in that one end of the connecting means engages a piston of the first pair, is deflected on the drive shaft and at the other end with a piston of the second Pair is connected. 13. Piston machine according to one of claims 1o - 12, characterized in that the connecting means as a band of elastic material, preferably Spring steel sheet, is executed. 00 9846/0386 Blank page