DE3438219A1 - Two stroke diesel engine with opposed free pistons - Google Patents

Abstract

In the two-stroke diesel engine with opposed free pistons and hydraulic pump, the reciprocating movement of the free pistons, with complete balancing of masses in each cylinder, is converted into rotary movement by the hydraulic oil delivered by the hydraulic pump or pressurised water using a hydraulic motor or a counter pressure free jet turbine. According to the invention, in the case of two cylinders one of the buffer chambers of the opposed free pistons, which chambers are arranged in the cylinders, is connected to a starting injection pump, so that for a starting pressure of 5 bars following injection in this cylinder the injection gap is uniform due to the later injection into the other cylinder at a buffer pressure of 10 bars. In addition, a buffer chamber of each cylinder is connected to the injection pump of the other cylinder, so that injection can occur due to the compression force only when the buffer pressure is falling, any change of the injection gap being limited and compensated for by the injection delayed by the high buffer pressure. In addition, the pressure and intake valves of the hydraulic pump have an expanded, nozzle-shaped gap outlet and a constricted, nozzle shaped gap inlet with a wide, spherical valve seat, so that the pressure losses are low at high piston speeds.

Description

Two-stroke Bieselzi engine with counter-rotating free pistons 3438219

In the two-stroke diesel engine with counter-rotating free pistons Patent application P 32 Op 814 · .4- is the stroke movement of the free piston with complete mass balance in each cylinder by the Pressurized oil or pressurized water delivered by the directly driven hydraulic pump with a hydraulic motor or with a counter-pressure price jet turbine transferred in rotary motion.

The proposed two-stroke diesel engine has two counter-rotating free pistons in each cylinder with a thin pump inside. have pistons and form a buffer chamber with the pump cylinder.

The counter-rotating free piston, which is delayed by the buffer pressures and are accelerated, are maintained in a steady state by the buffer pressures.

Due to the counter-rotating free pistons, the engine has a complete Mass balance, a direct current flush without valves, low. Friction losses and low. "Heat losses. In addition, the free pistons have simple piston ring seals and are in the water-cooled cylinders by the

: Buffer air well cooled.

The purge air is supplied by an exhaust gas turbocharger. A complete injection pump belongs to each cylinder Compression drive.

The injection quantity is sailed automatically. by the Load-dependent delivery pressure of the hydraulic pump.

The injection pumps arranged above the compression chambers are switched on and off by a switching rod also connected by lines to the starter compressed air valves and the starter injection pump.

By tangential injection with a single-hole injection nozzle In the compression chamber, the air charge circulating in the same direction results in good mixture formation and complete combustion achieved

With a control range of 16 to 200 bar, the pressure air vessels are the hydraulic pump at the minimum pressure by spring-loaded Piston valves shut off so that only small pressure air vessels are required.

BATH ORIGINAL

The one required for the synchronism of the two free pistons rotating in opposite directions Setting the same pressures in the two buffer channels takes place with a charge controller by regulating the charge quantities. According to the invention, in the case of two cylinders, one of the buffer chambers arranged in the cylinders is the opposing free piston with a Starting injection pump connected, thus at a starting pressure of 5 bar after the injection in this cylinder by the later one Injection into the other cylinder at a buffer pressure of 10 bar / the injection interval becomes even According to the invention, a buffer chamber is also connected to the injection pump of the other cylinder from each cylinder so that the Injection by the compression pressure can only take place when the buffer pressure falls, with a change in the injection interval limited by the injection delayed by the high buffer pressure and is balanced.

According to the invention the penetrating into the buffer chambers have: rump cylinders the hydraulic pump has an insulating jacket so that the pump cylinders do not get too hot.

According to the invention, the pressure and suction valves of the hydraulic pump have one free. Flow with a smooth surface, a closed valve guide , an enlarged, nozzle-shaped gap outlet and a narrowed, nozzle-shaped gap inlet with a broad, convex Valve seat, thus by utilizing the greatest salt speed in the enlarged nozzle and due to the effect of the smallest gap pressure on the valve spring in the valve, only pressure losses occur the gap friction and the high salt velocities occur when the valve closes too late.

The proposed regulation of the injection interval for two .-: Cylinder by influencing the starting injection and the injection with buffer pressures has the advantage that the design the buffer chambers is easier and the cooling of the free piston is cheaper than with two cylinders with one hydr. Piston connection.

With the high efficiency of the hydraulic pump and a back pressure-free With the low heat losses of the two-stroke diesel engine with counter-rotating free pistons, strahl turbine is the overall efficiency of the hydrodynamic drive is greater than the efficiency of a four-stroke diesel engine.

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In addition, the simple design has no crank mechanism and Cylinder head at delivery pressures of 200 bar and piston speeds of 30 to 15 m / s at the high speed of a • back pressure free jet turbine, the power to weight ratio is much lower. The proposed Drives are_suitable for vehicles, ships, Conveyors, pumps, compressors and power generators. When the load is low, fuel is saved by partially operating the diesel engine.

In the drawing, the invention is shown, for example,

namely shows "

Sheet 1 a horizontal longitudinal section ^M 2 "vertical longitudinal section ¹¹ 3" cross section ''"

a two-stroke diesel engine with counter-rotating free pistons ⁿ 4 · an injection pump with compression ^{drive n} 5 "starter injection pump with compressed air drive" 6 a longitudinal section through three nozzle ball valves ■ "7." ... "" a charge regulator.

The basic shape of these motors is aus'zwei Λ cylinders with two counter-rotating free piston 2, .the with thin pump piston 4 of the externally located hydraulic pump 3 are connected. .

The pump body 5 inserted into the cylinder form canoe formers buffer P for the free piston, which are delayed in the expansion by the buffer air, and then accelerated by the buffer air during compression.

The same pressures required for the synchronism of the two counter-rotating free pistons of a cylinder ..- in the two buffer chambers are set with a charge regulator by regulating the charge quantities.

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The motor works with a direct current purging without valves. The inlet slots E and outlet slots A located at the outer stroke ends of the free pistons are hereby the free pistons controlled.

The scavenging air is from the exhaust gas turbocharger 40 through the charge air line 42 is pressed into the cylinder and displaces the remaining exhaust gas into the exhaust pipe 41.

The injection pumps 10 driven by compression air connected to the compression chambers located in the middle of the cylinders.

Starting takes place when the. Glow plugs 29 through Compressed air and a starter injection pump, kit of the shift rod. The pressure oil or pressure water delivered in the circuit by the hydraulic pump drives a hydraulic motor or a back pressure free jet turbine at .

Direct current purging takes place through the tangential inflow of the purging air with twist.

As a result, the exhaust gases are completely flushed out and there is also a tangential injection with a single-hole injection nozzle A good mixture formation is achieved in the air charge circulating in the same direction on the cylinder wall. The burning, which begins with the fuel particles facing the air, " runs in the compression chamber from the outside to the inside and is therefore is-calibrated and complete at low injection pressure and lower air ratio. '■

The proposed The engine is therefore suitable for various fuels .

Since with the counter-rotating free pistons the surface-to-volume ratio is small, the heat losses are also small. ■

The proposed Engines are fast thanks to the good mixture formation and the injection pumps with compression drive Run suitable and can also be used by exhaust gas turbochargers with medium. Press 9 "to 1f?"> work bar. ■

To ensure that the poufs work properly, the Buffer air autom. can be filled with "- compressed air.

Each buffer is therefore equipped with a charge air line 52 and a kick valve for the buffer chamber P executed.

Because the accelerations of the free piston by the buffer pressures are smaller than due to the combustion pressures, the free-

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Piston speed nth in decline is smaller than in decline, - · _ The decline that begins earlier and ends later than the Going forward, the compression work is due to the kinetic energy done by two free pistons.

A complete injection pump IO belongs to each cylinder Fuel pump driven by the compression pressure will .

The injection quantity is regulated automatically. Via a regulating mandrel and a regulating spring through the delivery pressure of the hydraulic pump, which is dependent on the load.

Except for the connections for the injection line 22, the fuel line 21, the compressed air 23 and the pressurized oil or Pressurized water 24 are the connections on the housing of the injection pump for the starting compressed air; 25 and the starting injection quantity 26 arranged with check valves.

The limitation of the injection quantity in propulsion engines of ships and pumping is carried out by a control rod 16 located above the injection pumps, which controls the stroke of the control domes via thin bolts limited .

2 for switching the cylinder pairs on and off by switching them on and off of the fuel pumps, the shift rod 18 is required, which is attached to the pump piston of the fuel pumps via thin bolts attacks and also the starter compressed air valve at the Adjustment switches. '

For each pair of cylinders, the 'starting compressed air valve for the "both lines 25 through the shift rod at standstill. · closed and open during operation; the starting valves 35 of the pump cylinders, 'which open when stopped; are, will be at Starting closed by the starting compressed air.

Each pair of cylinders includes two pressure air vessels 33 and two suction air vessels 34- ·.

The pressure air vessels are connected to compressed air via check valves 16 bar and are shut off at this pressure below by piston valves.

At a delivery pressure of 160 bar is the volume of a pressure air vessel about 30 times as large as the delivery rate / stroke; the max. The change in pressure at 160 bar is about 10% and at 80 bar Only 5 % .

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Beirr: Switching on a starter compressed air valve 12, compressed air flows in both cylinders and the pre-piston are almost in the middle position up to when the starter pump valves are open a starter injection takes place at a pressure of 5 bar in a cylinder. During combustion, the free pistons are grounded by the Higher gas pressures accelerate outwards and the buffer air is compressed up to a pressure of about 10 bar, the start-up injection takes place in the other cylinder / so that the injection interval is uniform.

After this push, the normal injections take place as soon as the compression pressures have risen to 30 bar. In addition, at higher gas pressure the starter piston valves, which are only open in the middle position, and the starter '" Pump valves closed. ·.

The starter injection pump driven by compressed air with xwei The pump piston and control slide are connected by lines to the injection pump of each cylinder.

Spring-loaded piston valves are arranged in these lines, which are closed at high and low pressures in the cylinders and are only open in the middle positions, at pressures £ or iO bar.

By locking the pump piston with the piston slide valve the starter injection is only carried out once in each cylinder when a pair of cylinders is switched on ..

BATH ORIGINAL

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On sheet 4 in Fig. A is a. Longitudinal section through the injection pump and in Fig. b a longitudinal section through the fuel pump and the control mandrel shown for the injection pump. Figs c 'and d'show Cross-sections through the common housing.

In the case of the injection pump; which does not have a mech. The drive has ^ is the pump piston 70 is driven by the compression air via the spring-loaded piston 71 and the injection valve is used as a pressure valve.

In the fuel pump, the spring-loaded pump piston 72 is also driven by the compression air. The displacement of the fuel quantity takes place during and after the purging by the spring. The inlet opening of the injection pump controlled by the pump piston 10 is therefore open at low gas pressures during and long after the flushing. '

The injection is also carried out by the rear of the pump piston lying throttle nozzle 73 throttled. so that the combustion pressures do not rise too high.

The injection quantity is regulated by the regulating mandrel 74 behind the fuel pump and through the pressure relief valve -75 for the excess Fuel. ■ '. ·

The piston 76 connected to the "Hegeldorn." the delivery pressure is printed against the Eegelfeder 77. The injection quantity is therefore dependent on the delivery pressure.

In addition, the injection pump still has the check valve -78 and the Connection for the starting injection quantity - the connection for the starting compressed air on the channel to the compression chamber, the locking pin of the shift rod 18 for the fuel pump and the locking pin of the control rod 16 for the control mandrel of the injection quantity.

When starting, the internal positions of the free pistons are limited by the spring-loaded locking pins in the middle of the cylinders 16.

The starting compressed air valves 12 and the starting valves 35 of the pump cylinders remain closed during operation at gas pressures above 15 bar.

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On BIa ^- Ct 5, Fig. A shows a longitudinal section and Fig. B shows a cross section of the starter injection pump. The starter injection pump consists of two pump pistons SO, which are connected to spring-loaded compressed air pistons 81, the control slide 85 for the compressed air and the spring-loaded piston slide 82, which trigger the system injections in two cylinders at a pressure of S or ΊΟ bar. When the compressed air is switched on, the control slide is adjusted by the switching rod 18 via a linkage. The control spool is changed over at the end of the stroke by a compressed air piston via the driver M. After the compressed air has been released, the two pump pistons are pushed back by the springs; When switching on, the spring-loaded control slide is adjusted via a linkage by the switching rod 18 and held in place by the spring-loaded locking lever 84 until the locking lever is pushed out of the locking position by a compressed air piston at the end of the stroke. After the compressed air has been released, the two pump pistons are pushed back by the springs.

The delayed valve closing, which is inevitable with the short stroke times is cheaper with the pump piston driven directly by the free piston than with a piston pump with a crank drive because here the free pistons are driven without friction losses when the pressurized water flows back, and because the Water in the suction air vessel also the drive power as the actual flow rate is smaller.

For rapid opening of the suction valves and a strong • acceleration of the air flowing into the pump cylinder water a form of • 4 is in calf speeds 10-15 ni / s to S bar is required in the return line.

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According to sheet 7, each buffer chamber has a charging line 52 with a check valve 53. When the pressure rises in the buffer chambers block the non-return valves by back pressure and the two buffer pressures load the piston valve 55 via the lines 54 / which, due to the larger buffer pressure, reduces the loading gap with the smaller buffer pressure to the minimum gap and the other Loading gap enlarged.

Close the valve that is released when the pressure rises in the buffer chambers occurs, the. Check valves 53 through Springs are opened, with small valve gaps by the Back pressure loaded.

The return flow displaced when the valve closes flows when The valve opens again into the buffer chambers due to the higher pressure in the loading channel 56.

This is done in the buffer chamber with the higher buffer pressure due to the larger loading gap, the load is larger. Since the buffer pressure with a larger load for the same buffer work but falls, always arises in the two buffer chambers again the same pressure and the two opposing free pistons 2 are thereby in the end positions the same distance from the Buffer piston 5 and stay in sync.

The charging pressure of the buffer chambers is set by a pressure reducing valve regulated by the delivery pressure of the hydraulic pump. thus the buffer pressures for heavy loads at higher boost pressures don't get that high. .

The backflow of the buffer air into the charging channel 56 when the non-return valves are open also reduces the buffer charging pressure a rapid progression when the load falls.

In the water-cooled cylinders there is a favorable heat transfer between the long free pistons. J and the compressed air in the buffer chambers P the previously proposed. Cooling by water in the piston connections is not required. In addition, at a higher free piston temperature, the heat loss of the buffer air is lower and the efficiency of the diesel engine is lower is therefore higher here.

For lower heat losses and for weaker cooling also proposed free pistons with insulated bottoms.

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According to sheet 2, according to the invention, with two cylinders, one of the in the cylinders arranged buffer chambers P of the counter-rotating free pistons connected to a two-cylinder starter injection pump 11, which injects at a starting pressure of 5 bar through the first pump cylinder into the first motor cylinder and then at a "buffer pressure" of 10 bar in this cylinder through the second pump cylinder into the second motor cylinder is thus injected through the later start-up injection into the second cylinder a uniform injection interval is achieved.

In addition, a buffer chamber of each of the two cylinders is connected to a piston valve of the injection pump 10 of the other cylinder so that the injections can only take place when the buffer pressure falls, whereby the injection interval is changed the injection delayed by a high buffer pressure is limited and compensated.

When regulating the injection interval for two cylinders influencing the start-up injection and the injection with the. The design of the buffer chamber is simpler than the buffer press with a hydr. Piston connection for two cylinders and it will kick no pressure loss. In addition, in the water-cooled cylinders, the cooling of the free pistons by the buffer air is more beneficial and the expansion of the buffer air has no losses due to the hot free pistons.

The penetrating into the buffer chambers pump cylinders 5 have a Insulating jacket I so that they don't get too hot.

For the desired goal / that the proposed Diesel engine at simple Type a low. Power-to-weight ratio and low fuel consumption has pressure and suction valves 31 and 32 with short stroke required for delivery pressures of 200 bar and for piston speeds of 15 m / s at .. gap speeds of 30 to 40 m / s have a low pressure drop.

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After sheet '&. The nozzle ball valve proposed for the pressure and suction valves of the hydraulic pump consists of the valve body with the inserted valve guide 91, the spring sleeve 92, the valve spring 93 and the valve ball 94 and has a free flow with a smooth surface and an enlarged, nozzle-shaped gap outlet A and a narrowed, nozzle-shaped gap inlet E with a wide, spherical valve seat.

The gap entry is narrowed by the spherical valve seat, so that the gap speed increases up to the enlarged gap outlet and is used more favorably here.

In addition, the valve spring is only affected by the larger one Gap pressure compressed in gap entrance. Since with 'this mode of action only pressure losses due to the gap friction and the high speed of cracking occurs when the valve closes late, the hydraulic pump has a high degree of efficiency .

The speed that increases up to 6 m / s when the valve closes of the valve ball is strongly delayed by the high pressure increase when the water is displaced in the valve seat.: As during the expansion the piston acceleration * is greater than during the decrease,

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is the piston speed for a stroke of 150 mm and a stroke rate of 6000 min. in 0.001 seconds when closing the suction valve approx. 10 m / s and when closing the pressure valve approx. 5 m / s. Although the piston speed in the delay in the opening of the pressure valve about 14 m / s, no pressure surges occur because the Verdrägungsgeschwindigkeit the pressure valve ball bar uniformly increases by a ram pressure of 240 in the simultaneous delay of Saugventilkugel. Ga when opening the suction valve the acceleration of the suction valve ball by a pre-pressure of 8 bar occurs simultaneously with the deceleration of the pressure valve ball, the filling of the pump cylinder takes place at piston speeds of 10 m / s without pressure surges and the pump pistons are due to "a pressure of about 6 bar driven.

With the small valve gaps, the braking quantities with gap pressures of up to 600 bar and gap speeds of up to 170 m / s are very small; the harmful effects of the radiation are therefore slight. The pressure losses due to the gap friction and the high gap speeds when the valve closes late are around 4 %. of the conveyor bridge 2CO bar.

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During the seceiung of the injection through the delivery pressure of the Kydropucpe does the proposed Motor faster with heavy loads than with light loads.

Since the speed of the hydrometer drops with increasing load, will the excess flow rate of the Hydropunpa in the pressure air vessel repressed. Due to the associated increase in pressure, the injection quantity is bigger and the diesel engine runs faster. If the pressure continues to rise and the pressure drops, the hydraulic motor is activated accelerates when the pressure relief valve is open until it can displace the entire delivery rate of the Hydropucipe.

Delivery pressure, injection quantity and speed are therefore dependent on the load addicted

Since the delivery pressure, 'the injection quantity and the Speed dropping to the idle limit is a runaway from the suggested one Motor excluded. .

The torque of the oil motor, which is dependent on the delivery pressure, has through the pressure air vessel has a balanced course.

Due to the oil flow at overpressure, the cylinder pairs have been started • a smooth course without interrupting the tensile force. Short reductions in the speed of the oil motor to a standstill take place through an adjustable throttle valve in the pressure line. When a pair of cylinders is switched off, the hydraulic motor is idling for as long until its speed corresponds to the reduced delivery rate of the hydraulic pump.

A connection line with a non-return valve is required for idling the hydraulic motor required between the pressure line and the oil cooler so that if the delivery rate is too small, the oil flow to the hydraulic motor is large enough is .

The delivery pressure, speed and power are regulated when combining the hydraulic pump with a back pressure free jet '' turbine by adjusting the nozzle needles. When the nozzles are open, the hydraulic pump is idling.

Switching the diesel engine increases the power of the hydraulic engine the speed and, in the case of the back pressure free jet turbine, the torque.

Partial operation of the diesel engine also saves fuel when the load is low.

BATH ORIGINAL

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Through the low Failure to print in the gg the efficiency of the hydraulic pump driven directly by free pistons at a delivery pressure of 200 bar and piston speeds from 10 to 15 m / s between 0.97 and 0. ° A

With the high efficiency of the hydraulic pump and the back pressure free jet turbine and at the low. "Heat losses from the two-stroke diesel engine with counter-rotating free piston can with an overall efficiency of the proposed. Drive calculated from 0.4 to 0.45 will .

In addition, the simple design ~. -O.without a crank drive and Cylinder head at the high speed of a back pressure free jet turbine the power to weight ratio is much lower than that of a four-stroke diesel engine .

The proposed Drives are with complete mass balance, smooth running, favorable drive torque, simple control and of a simple, robust design suitable for driving. Vehicles, ships, conveyors, pumps, compressors and Electricity producer.

BATH ORIGINAL

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Claims (4)

Cl) two-stroke diesel engine with counter-rotating free pistons, in which the stroke movement of the free piston is transferred in rotary motion by the pressure oil or pressure water delivered by a directly driven hydraulic pump with a hydraulic motor or with a counter-pressure free steel turbine, characterized in that with two cylinders one of the four externally arranged buffer chambers (P) of the counter-rotating free pistons is connected to a two-cylinder starter injection pump (11) which injects through the first pump cylinder into the first engine cylinder at a starter boost pressure of 5 bar and then into the first engine cylinder at a buffer pressure of 10 bar This cylinder is injected through the second pump cylinder into the second engine cylinder, so that with a simple design of the, buffer chambers and favorable cooling of the free pistons through the later start-up injection into the second cylinder, an even injection interval and thus a favorable flow rate in the hydraulic pumps of the two cylinders is achieved. 2. Two-stroke diesel engine with counter-rotating free pistons according to Claim 1, characterized in that each of the two cylinders has a buffer chamber with a piston valve of the injection pump (10) of the other cylinder is connected so that the injections can only take place when the buffer pressure falls, where a change of the injection distance by the one high buffer pressure delayed injection is limited and compensated. 3. Two-stroke diesel engine with counter-rotating free pistons according to claims 1 and 2, characterized / that the in the Pump cylinders (5) of the hydraulic pump penetrating buffer chambers have an insulating jacket (I) so that they get too hot at night. BATH ORIGINAL 4. Two-stroke diesel engine with counter-rotating free pistons, in which the stroke movement of the free piston through the pressure oil or pressure water delivered by a directly driven hydraulic pump with a hydraulic motor or with a counter pressure free jet turbine is transmitted in rotary motion, characterized / that the pressure and suction valves (31 and 32) of the hydraulic pumps a free flow with a smooth surface, a closed valve guide (91), an enlarged nozzle-shaped gap outlet (A) and a narrowed nozzle-shaped gap inlet (E) with a wide, spherical valve seat, thus by utilizing them the greatest splitting speed in the enlarged nozzle and by the effect of the smallest splitting pressure on the valve spring (92) in the valve only pressure losses due to the gap friction and the high gap speeds in the case of the delayed one Valve closing occur.