DE1911351A1 - Engine braking system for a motor vehicle - Google Patents

Description

Diving. Wilhelm Beichel

Frcmkfuii / Main-l "~
Porkai »ißel3

584 2

WHITE MOTOR COIiPORATION, Cleveland, Ohio, V. St. A.

Engine braking system for a motor vehicle

The invention relates to an engine braking system for a Motor vehicle powered by an internal combustion engine several cylinders and corresponding pistons is driven.

There are known various arrangements for temporarily converting an internal combustion engine into a compressor, by ending the combustion in the engine and cyclically venting the engine cylinders to the atmosphere. The USA patent 3,367,312 entitled "Engine Braking System" which issued on February 6, 1968 describes e.g. devices that can be operated by the driver in order to reduce the workload of the exhaust valves of an engine by 180 ° with respect to the rotation of the engine crankshaft so that the Exhaust valves open the cylinders at or near the end of the Vent the pistons' compression strokes.

It is also known to achieve the same purpose when the flow of exhaust gas from the exhaust pipe of an engine is restricted to create back pressure for energy dissipation produce. Such a braking system is e.g. in the United States patent ~ 2 805 656 explained. ',

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These two well-known Kotorbrern systems have certain peculiarities Disadvantage. The disadvantage "in bringing the The point of use of the exhaust valves in the first system Lo a tent in having to provide an auxiliary tax system for all of them Outlet valves cyclically, "at dea advanced sowing time to be actuated over a specified 3 braking period. Sin such a thing Kilfssteuersyote; .-; comes with numerous moving files Significantly expensive to manufacture and require periodic maintenance. The two brake systems eliminate that Necessity of cyclical control in) advance of the braking period, but the extent to which energy is consumed depends on the size of the back pressure in the exhaust pipe, and Difficulties eventually arise when the back pressure is relatively high, z.3. etv / a 2, es kg / cm (40 p.s.i.). The object of the invention is to address these disadvantages Operation of an internal combustion engine as a vehicle auxiliary muzzle device to avoid.

It should also exclude the need for the driver of a motor vehicle any special or Additional controls operate nut, including the engine on a braking process ura zu cha Ix en. In particular, the Br eic 3 sys te id in the sense to be made automatically, - that the braking process on Desire takes place automatically, without the driver having to deviate from conventional vehicle guidance. ·

Such an automatic braking process leads to certain important advantages. In the first place, the aim is to ensure that a driver, who is the first quay, has a truck does not drive, which contains the subject matter of the invention to get used to a new manually operated controller needs and is not forced to adopt new vehicle control methods to acquire. Correct operation in the event of any sudden emergency is assured. Second Place it is noted that the automatic braking process the

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Fatigue is reduced as the driver is at all times can drive relaxed. In third place one reaches the rider automatic braking the full power of the engine braking, saves fuel and also reduces wear on the mechanical brakes. In fourth place is the automatic Kot orbremsung in contrast to the mechanical Braking practically ruled out that the vehicle engine on a downhill run cools down impermissibly, especially in the Wirrt he time. An effective, automatic faecal braking is enabled it is also to switch to high gear before that ]? vehicle has lost so much speed that the desired gear shift is impossible.

The invention is also intended to provide a so-called "safety controller" created, i.e. a fail-safe brake control, which takes effect immediately in the event that the driver unable to approach the driver or thrown from the driver's seat will.

A preferred embodiment of the invention is intended to continue a graduated i-Io gate braking process can be made possible, and This is in contrast to a conventional engine braking system, in which the driver is between a maximum braking process or no engine braking at all, select nraß. It is desired to be different for different situations To create braking values or gradations. For example, before a final stop or after a certain distance over a large part of the distance are braked weakly to the acceleration of the Pahrzeug relative gradually reduced, and then a stronger braking can be carried out in the end section. When using conventional mechanical or hydraulic brakes or air brakes, it is relatively easy to change the extent of the braking process as desired, and the strength of the Braking varies, of course, with the amount of movement

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a manual brake control. It is therefore τ most, desirable, to create a Mot or Lr-erass ystem, its efficiency changes in the same graduated manner as the progressive or progressive movement of a Brent tax part.

The presently preferred embodiment of the invention is based based on three basic discoveries that you want for Cooperate energy consumption by the engine. '

The first discovery is that an internal combustion engine uses up energy for the purpose of braking when the various cylinders are vented through special openings or when either the intake valves or the exhaust valves of the various cylinders are prevented from moving to close beyond partially open positions as long as the braking process is desired. The fact that either the intake valves or exhaust valves are continuously at least partially open eliminates the need for a cyclical valve actuation over an entire braking period required, and it can therefore be a relatively, ..- simple one Control arrangement are provided.

In the preferred embodiment of the invention, the Closing of the exhaust valves prevented, and the partial; wise open exhaust valves lead during the ■ suction strokes Piston slightly more than the usual amount of air in the cylinder a, which leads to larger amounts of trapped air at the beginning of the compression strokes. As a result, the - through the Pistons lost energy during the compression strokes. More important, however, is the energy loss due to heating ' the air that escapes through the exhaust valves during the compression strokes, and it is consequently the compressed. Air through the partially open outlet valves during the work or expansion of the KoI * ben more power consumed. The new result of these effects

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consists in the fact that the power that the engine returns to the vehicle during the expansion strokes of the pistons, is significantly less than the power absorbed by the engine during the previous compression strokes. The difference that counts for the braking by the engine can only be achieved by not opening the exhaust valves can be closed completely.

The second discovery is considered to be that when a second engine braking operation is carried out simultaneously, that by using a throttle valve for producing a back pressure in the exhaust pipe, the two complement different ä loan braking. The flow through the exhaust valves causes energy to be dissipated on the combined compression and expansion strokes, while the back pressure in the exhaust pipe results in additional energy dissipation by increasing or increasing the differential between the suction and working portions of the engine cycle that are not mutually exclusive disturb.

The third discovery is that the combined effect of the two complementary engine braking is greater than the sum of the two separate braking effects. The unexpected interaction of the two simultaneous braking is in large part attributed to the fact that the exhaust back pressure forces more air through the partially open exhaust valves into the cylinders on the intake strokes and during the initial portions of the compression strokes. So if you keep the exhaust valves open, and together with that maintain an increased pressure in the exhaust pipe, this causes a considerable compression or pre-compression in order to increase the amount of energy that is consumed by the engine during the combined compression and power strokes. The pressure that works against the compression stroke of a piston is considerably higher than the counteracting pressure,

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beirr due to partially open exhaust valves, lack of Exhaust back pressure would be generated.

, Since the liutzbremsieistun, ;;, which taken together "with the compression and expansion strokes received compressed by the rreigabe air in the expansion strokes, depends, seems au Γ first glance dio Anhebun _ö - the back pressure in the exhaust pipe venting aer compressed air at the The fact is that when the exhaust back pressure is selected, the pressure differential across the partially open exhaust valves by far exceeds the critical pressure ratio, above this If a back pressure, ζ.Ιί. a back pressure of 1.4 kg / cm (20 psi) la exhaust pipe is generated, the critical pressure ratio across the partially open exhaust valves will still be exceeded over such a large "part of the expansion stroke that the influence of the back pressure on the vent is relatively insignificant.

The invention will now be described in detail with reference to the accompanying figures, with all details or features emerging from the description and the figures being able to contribute to the solution of the object within the meaning of the invention, and ax the will for patenting has been included in the application . Show it:

Fig. 1 is a diagram showing the cylinder pressure versus the X crankshaft angle during an engine braking process, which is achieved exclusively by continuously, at least partially opening either the intake or exhaust valves. is achieved; ·

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Pig. 2 a similar diagram, since α on cylinder pressure versus the KurLoiwellon angle with a) raotorliremsvor- gang aoijt, which is solely by maintaining

■ ρ of a back pressure of about 1.4 kg / cm (20 p.s.i.) im Exhaust pipe of the Kotors is effected;

Pig. 3 shows a similar diagram, which repeats the curves of Piguren 1 and 2 and additionally shows the cylinder pressure versus the crankshaft angle during a Kotorbremsvorgang that by preventing a complete closure of the exhaust valves and by simultaneously maintaining a back pressure of about A. ρ ™

1.4 kg / a (20 p.s.i.) is produced in the exhaust pipe;

Pig. 4 is a diagram illustrating the power consumed at different engine speeds; some curves affect the performance. which is only destroyed by keeping the exhaust valves open to various degrees during the part of the engine cycle in which the exhaust valves are normally closed; a graph showing how power is simply destroyed by the fact that a back pressure is maintained in the exhaust pipe, and yet -a further curve shows how power is consumed when the exhaust valves are prevented to close v'oliständig A, while in the * Exhaust pipe a counter pressure is maintained.d;

Pig. Figure 5 is a schematic view of the currently preferred embodiment the invention; - _

Pig, '6 is a schematic view of rope indicating how that in Pig. The arrangement shown in FIG. 5 can be changed to V / ung can;

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Pig. 7 is a schematic partial view of an embodiment of the invention exclusively, to the limitation the closing process of the exhaust valves for a Kotorbremsung is based and

8 is a similar view of a further embodiment the invention.

The Pig. 1 relates to a method in which an internal combustion engine consumes power solely by preventing either the intake valves or the exhaust valves of the engine from closing completely, and it further shows the duty cycle over two complete revolutions The working cycle of a given cylinder is divided into four parts, corresponding to the four strokes of the piston in the cylinder. These are the intake stroke, which extends from the top dead center on the left-hand band of the diagram to the bottom dead center of the crankshaft, which is represented by the vertical line 10; the compression stroke, which extends from the bottom dead center of the crankshaft, which is indicated by the vertical line. 10 extends to the top dead center illustrated by the central vertical line 11; the expansion or working stroke which extends from the top dead center position of the crankshaft, which is represented by the line 11, to the bottom dead center which is illustrated by the vertical line 12 and the exhaust stroke which extends from the bottom dead center position of the crankshaft represented by vertical line 12 extends to the top dead center position of the crankshaft represented by the right end of the diagram. To obtain space for the · - "middle Verdichtunga- and strokes can be clearly shown, the opposite end portions of the chart representing the intake stroke and Ausstpßhub, corresponds ,,; huddled together talking horizontally '.

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A small part of the energy is used on the initial suction stroke consumed, _ and further power is v ^ ied by the engine destroyed on the final exhaust stroke. The essential linear component, which is consumed during the compression stroke, can on the surface be raessened by the pressure curve 13 between the two vertical lines 10 and 11 is limited, and the power, which through the feces or leg: Aue stretching :: stroke on the ! Vehicle is returned is equal to the area bounded by curve 13 between vertical lines 11 and 12 will. One can see d & 3 the first face the second Area considerably, the difference being the net power required by the engine for the desired Braking effect is consumed "

The first face on the left side of the vertical line is greater alo the second face to the right of the Line as the opened exhaust valves release air from the cylinder during the compression and expansion strokes, thereby causing the air pressure in the cylinders during the first part of the work or expansion strokes suddenly falls off.

In Pig. 2, curve 14 represents the pressure changes in one Cylinder in a working cycle that extends over two revolutions the crankshaft extends when the braking process is solely based on maintaining a back pressure of 1.4 kg / cm (20 p.s.i.) is based in the exhaust pipe, v / o at the inlet and exhaust valves operate normally. It will be noted that in FIG. 2 the part of curve 14 in the third seam which corresponds to the Expansion stroke is a mirror image of that part of the curve which lies in the second space which is the compression stroke illustrated, there being no power absorption by the combination of these two strokes. the The power consumed by the motor for the desired braking effect is therefore the power that is absorbed during the intake stroke plus the power absorbed on the exhaust or exhaust stroke.

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Pig. 3 contains the print bar ve Yi aerPig. 1, which illustrates the braking process which "can only be achieved by preventing the exhaust valves from closing completely." co ffect that is achieved solely by maintaining a back pressure of approximately 1.4 kg / cv :) '"(20 psi) in the exhaust pipe. Also shows Pig. 3 for a third pressure curve 15, which illustrates the composite brake ffokt that nan achieved by keeping the exhaust valves partially open during the periods of time when they are normally closed and at the same time ate a back pressure of about 1.4 kg / cm (20 psi} ir. Exhaust pipe is maintained.

It can be seen that the energy absorbed at the outlet c the exhaust stroke is the same for both curves 14 and Y i. In other words, using two types of 3recs at the same time does not reduce the amount of energy consumed by maintaining back pressure in the exhaust pipe.

The height of the apex of the new pressure curve 15 is considerably lower than the height of the apex of the pressure curve 14, which illustrates the braking process that is generated solely by maintaining the counterpressure in the exhaust pipe. 2s, however, it is reminded that "the height of the apex of the pressure curve 14 is of no importance with regard to the braking process, since the apex is symmetrical with respect to the top dead center line 11. The power output during the expansion or working stroke is the same the power that is consumed during the compression stroke.

The surprising fact is; in that the apex of the pressure curve 15, which shows the two simultaneous Brerasvorgänge represents, is considerably higher than the

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Part of the pressure curve 13, and since the higher vertex of the pressure curve 15 is offset to the left with respect to the upper junction line 11, there is a considerably greater difference between the energy absorption and the energy output during the compression and power strokes. In other words, the difference between the areas delimited by curve 15 on the left and right side of the top dead center line is considerably greater than the difference between the areas defined by curve 13 on the left and right side the top dead center line. Pig. So 3 graphically shows that the maintenance of a back pressure in the exhaust pipe, while the closure of the outlet valves% is suppressed, bringing the expected energy dissipation in the intake and exhaust strokes, and also increases the energy absorption at the compression and power strokes.

In Pig. 4, in which the power consumed for a braking effect is plotted in horsepower for the engine speed, the lower curve 16 shows the braking effect of only the termination of the combustion in the engine's cylinders, while the braking effect is mainly due to the friction of the engine moving parts of the motor vehicle and motor vehicle is generated. The next higher curve 17 indicates the energy that the engine consumes when a back pressure of 1.4 kg / cm * (20 psi) is maintained in the exhaust pipe alone.

The next three curves represent the braking performance obtained by keeping only the exhaust valves of the engine open to various degrees during the periods of time when the exhaust valves are normally closed. Curve 18 illustrates the energy consumed when the exhaust valves are held open 0.25 mm (0.010 inches) curve 19 illustrates the effect of keeping the exhaust valves open 0.5 mm (0.020 inches) and curve 20 shows ultimately the power consumed when the exhaust valves were held open 0.76 mm (0.030 inches)

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will. From the curves 18, 19 and 20 it can be seen that a Increase the amount * the exhaust valves are kept open increases the energy used in the higher engine speed ranges is absorbed, but reduces the energy that is consumed in the lower engine speed ranges will. It will be understood that all of the curves in FIG. 4 relate to a particular engine which in this case is an 8 cylinder diesel engine. When operating any in other motors, however, the various curves have the general characteristics shown in FIG. In any case you come to a decision to what extent the exhaust valves are to be kept open that on the one hand the Desire to open the exhaust valves fairly wide for relatively high power absorption at higher engine speeds and on the other hand, the need for adequate braking at low engine speeds must be weighed against each other, which cannot be achieved if the exhaust valves are too open. In this particular case poses opening the exhaust valves by 0.5 mm (0.020 inch) is a convenient compromise.

Curve 21 in Fig. 4 shows the energy that is consumed when both braking processes are applied at the same time. i) The exhaust valves are continuously held open _y 0.5 mm (0.020 inches) and at the same time a back pressure of about 1.4 kg / cm ^ (20 psi) is maintained in the exhaust pipe.

For the relevant expert it can be seen that the through ' Figures 1 to 4 illustrated basic concepts different ways with different embodiments of the invention can be carried out. For example, Fig. 5 indicates schematically how the invention is incorporated into a truck which can be powered by a diesel engine will. An important feature of this particular embodiment the invention consists in different values the energy absorption represented by curves 16, 17, 19 and 21

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in. Pig. 4 are characterized by the truck driver to choose from To make use accessible. Another feature this particular embodiment of the invention-is therein beheld the various values of energy absorption by means of .to control the accelerator pedal, this feature being the addition makes an additional control superfluous, by means of which the motor could v / ground as an auxiliary brake. Another feature is ultimately aimed at making the engine braking process not only automatic, but also make failsafe.

In Pig. 5 is a multi-position switch, which is activated by the "

Switch arm 22 is shown, actuated mechanically by the accelerator pedal 24, as indicated by the dashed line 25 is. As is further indicated in a shear, the accelerator pedal 24 is pretensioned or reset by a suitable spring arrangement 25, and the same spring arrangement also serves to bias the switch arm 22 into a maximally retracted position, which is used as position l »r. 3 designated is.

Under normal driving conditions, when the accelerator pedal 2% ^ is depressed to supply fuel to the engine, the switch arm 22 is depressed below the rest position shown in | Pig. 5 is designated accordingly. If it. is desired to brake the vehicle, the driver raises the pressure on the accelerator pedal and allows characterized in that the switch Arts 22 can retreat to a selected extent, in accordance with the respectively desired degree of Bromsleistung. When the accelerator pedal can retract to move the switch arm 22 to the Ht position. To be set in FIG. 5 , the switch arm works together with a relatively long contact 28 in order to terminate the combustion in the cylinders of the engine. When the switch arm 22 \ retracts further to position # 2, it works not only with the long contact 28, but also with a contact. 30,

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thereby causing the exhaust valves; des l-Ictoro.-u: s Gin predetermined Ausir> a3 be opened while ale burn; r. £; is still interrupted. If, after all, aas "aspecai iri can withdraw its limit position, the 3 ehalt era χ ·;:; 22. returns to the position ITr. 3, in which it is not; only: r, it the contacts 2o and 30 cooperates, Gonaoi'n auoh r; .i ^ vie:. ¹ ? third brief contact 32, us to produce a counter pressure in; exhaust pipe 34.

In the in Jig. 5. "The control arrangement is located on the switch unit 22 in series with three switches, including a dashboard switch 35, a clutch pedal switch 3o and a gearshift lever switch"; he '' Jo. Dez- Ar.T.atui'encretx-Sc-hal'ier 35 can from: Eahrer to: switch off the 3re ^ 3kreioes cenutz; t v / ground, if. in: irer dies gevransch ": is. Isr Xupplu.i ^ sp'edal switch 35 is only closed when the clutch pedal 4-0 is released to engage the clutch of the vehicle and the gearshift it 33 is only closed when the gear shift lever 42 is outside of its neutral position.

Since 3 ¹ Ig. 5 relates to a truck powered by a diesel engine, the circuit terminating the. long contact 26 contains the combustion la engine by completing the fuel injection into the cylinder de.s Z'Iotors. For this purpose the long contact 28 is connected in series with a solenoid 44 ^{which is drivingly connected by a member L} 5 of an arm 46, which is a. Yen ~ il body 48 can rotate. In this particular 3 a11, the fuel injection devices 50 of the engine consist of a hydraulic design and are actuated by pressure pulses generated by a fuel pump 52. Since the. Pistons (not shown) of the hydraulic fuel injectors 50 merely serve in a known manner as control valves and are actuated by hydraulic pressure pulses instead of by squatting, it is not necessary to have any special ones

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Provide devices that the piston αer liinspritzeinrichtungen Start automatic operation when the fuel pump is switched off lot.

When the 4S valve body is in the irorr.al pitch indicated in Pig. 5, shown in full lines, for normal power operation of the engine, a recess 54 connects air. The periphery of the valve body is the outlet of the fuel pump 52 with a channel 55 which supplies fuel to the various injection devices 50 ′. When the solenoid 44 is energized, however, the valve body 45 is rotated into another position, which is indicated by dashed lines and in which the channel 55 is blocked and the Ur: far.-ε from the recess of the valve body is brought into a position in order to direct the output via the fuel pump i> 2 into a low-pressure return duct 56, whereby the combustion in the various Ko tor- * cylinders is ended.

If the vehicle engine contains an ignition system, it can Solenoid 44 can be used to open the ignition circuit and thus for the 2a11. an automatic collision Bring protection.

Each exhaust valve 53 of the various cylinders of the engine is biased into a closed position by the usual valve spring 60 and by a corresponding rocker arm 62 open periodically. In the usual way, the Rocker arm by a corresponding ITock 64 on a Camshaft 65 actuated, the docking in a known manner with a jib follower 66 at the lower end of a plunger 68 cooperates.

In order to keep the various exhaust valves 58 in a partially open position during the periods of time in which they are normally closed, an eccentric "70 is attached to a shaft 72 for each outlet valve, which is

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actuation arm 74 is controlled, normally LoTiTKiGi; ". each eccentric 70 "in a rotational position with enough space for normal operation acs corresponding rocker arm. 62 is available. If in: aer the contact 30 through the switch- ' arm 22 is applied to voltage, but v / ird a circuit Closed via a solenoid 75, which is connected by a member 76 the Letatigungaarrc 74 is connected. That energized solenoid rotates each eccentric 70 to a rotational position that controls the return movement the corresponding rocker arm 62 blocked. To this Manner, each of the exhaust valves 58 is continuously increased by one ' a predetermined amount kept open as long as a braking effect is desired by the engine.

The third contact 32 is used to excite a solenoid 78, which is connected to an actuating arm 62 by a link cO is. The actuator arm is as shown by the dashed line 85 is indicated, connected to a throttle valve 84 in the exhaust pipe 34. Normally, the throttle valve 84 is in the in the open position shown in Fig. 5 and allows free flow of exhaust gas out of the exhaust pipe 34. However, if the solenoid 78 is excited, the throttle valve is so far in the Schiossene position vorscnnelt that the exhaust gas flow from the The exhaust pipe is restricted enough to generate a gas pressure of about 1.4 kg / c; fi (20 ρ.ei.).

From the foregoing description it can be seen that the switch arm 22 in conjunction with the contact 28, the solenoid 44 and the valve 48 forms a first control device in order to terminate the combustion in the i-Iotor. The switch arm is further in connection with the contact 30, the solenoid 75 and the cam 70, a second control device to the exhaust valves partially oL'fcnzuhalten ^ and finally the switch arm is in connection with the contact 32, dom solenoid 78 _Λ ■ and the throttle valve 84 a third control device for; Creation of back pressure in the exhaust line. It can also be seen that the accelerator pedal 24 is a master control to which the first, second and third control devices are responsive.

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The manner in which the braking system works and fulfills its purpose goes beyond the previous description of the Pig. 5 emerges. It can be seen that if the dashboard switch 35 is closed and at the same time the clutch is engaged and the transmission is not in the neutral setting, the switch arrest. 22 is applied to the cooperation with the three contacts 23, 30 and 32 to voltage. If the accelerator pedal 24 can retract from a rest position enough to bring the switch arm 22 into its No. 1 position, the combustion in the vehicle engine is terminated in order to produce the weak braking effect caused by the. Turn 16 in Pig. 4- is indicated. If the accelerator pedal can be reset further to put the switch arm 22 in its Kr. 2 position, the switch arm also works together with the contact 28 to prevent combustion in the cylinders of the engine and acts at the same time he with the contact 30 together to keep all exhaust valves in partially open positions and to generate the motor brake effect, which is indicated by curve 19 in Pig. 4 is shown. When the accelerator pedal 24 is completely relaxed or released, the switch arm 22 takes its ^ r. 3 position, in which it cooperates with the contact 28 to prevent combustion in the engine cylinders and at the same time cooperates with the contacts 30 and 32 to keep the exhaust valves partially open and also to close the throttle valve 04. The result of moving the switch arm 22 to position # 3 is the engine braking effect, which is illustrated by curve 21 in FIG.

It can be seen that the engine braking process is automatic in this sense is that the braking effect is automatically generated whenever the driver releases the pressure on the accelerator pedal in order to achieve the Vehicle to slow down. Since the driver can choose from three different strengths of braking performance, he can do the Driving trucks reliably and braking to an extent that that does justice to every special situation. Since the brake

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ang by-the Xotor automatic forward;., kar.n .jich dor " Driver mainly to the Motorbror.'sir.v; let go. the Conventional mechanical brakes have been kept in reuerve for emergencies, and overheating dor r ^ oohanischen brakes on long years of learning is avoided. 7 / onn the truthful out Any:. * Reason unfit to drive, or if the elder in one: accident is thrown from coiner seat, works, the engine braking system instantly with a: .-.-a-ximal effect. '- ■

As already pointed out, the three strengths correspond to a brake university; curves 10, 19 and 21 in that order in?! £. 4. If it is necessary to change this ΓΌΙ / je, you only need to change the wiring connection to the three contacts: "Gen 2β, 5C and 32.? I _t ;. C soigt 2.3. that the Xon ~ al-: t 30 πϊτ de :. '; solenoid 73 is connected instead of r ^ it to the solenoid'7i>, whereby the contact 32 r ^ i " _u de:.: solenoid 75 is connected , instead of π; -ϊτ de :. '; Solenoid 73 * 2 in this new circuit arrangement causes the switch array 22a to be moved into its Xr. 2 position that the throttle valve 84 closes in order to generate the ircus effect that is inherent in the curve 17. 4- and not shown by curve 19.

Pig. Fig. 7 shows the construction of another embodiment of the invention in which the Mctorbreas process is achieved solely by keeping the exhaust valves of the cylinders partially open. The switch arm 22b in? Ig. 7 is shown in the rest position of the accelerator pedal. The switch arc 22b can be reset to the position Kr. 1, in which it interacts with the contact 86 in order to excite the already mentioned solenoid 44 to terminate the combustion in the engine. The switch arcj 22b can continue to the position iir. 2, in which the switch aria cooperates not only with the) contact 86, but also π it of the contact 88, ura to energize the already mentioned solenoid 75, which keeps the various outlet valves in a partially open position. "

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Pig. ö shows the construction of a further embodiment of the invention in which the switch & rm 2. ' ο in the cow posture shown lit. the salary;:; 22c can be in position Kr. 1 be reset, in which he is excited with a contact 90 of the solenoid 4 4 · cooperates that the combustion ended in the engine. V.'onn the switch arm 22c in the limit position is reset, which is marked as position Kr. 2, the switch arm works not only with contact 90, but also cooperates with a contact 92 to energize the solenoid 75, which keeps the exhaust valves partially open, and the The switch arm also cooperates with a third contact 94 to energize the aforementioned solenoid 73 and the throttle valve 34 to close. ™

The one in Pig. The arrangement shown in Figure 5 includes a normally open switch 95 which can be omitted if desired. This switch is within an expedient range of the Pahrex-s and, when closed, bypasses the gear shift lever switch 38 in order to render this switch ineffective. The advantage of the arrangement of the switch 95 is that the driver can temporarily close it to facilitate the engagement of gears for acceleration on a straight road. To perform such a transmission circuit, have the drive and driven gears in gear dux * ch deceleration of the motor synchroniciex't etc. are and beim- 3etrieb a conventional diesel truck engine brakes so gradually from that too often the vehicle su much lose speed before the gear shift can be performed. When switch 95 is closed, the driver can release the accelerator pedal and place the gears in a neutral position to allow prompt braking of the engine by the engine braking system. When the motor is braked enough to enable the synchronization of the desired cogwheels, the driver shifts the gears and he can then switch the switch 95 back to its normal open position.

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Claims (25)

Claims. "■ - ■ ■" Λ?) Mc 1J engine braking system for a motor vehicle operated by a Ver-VJrcennuiigskraftmajchine Kit driven by several cylinders and corresponding pistons, d & .d u r c h g e k e η η - draws that for a use of the Kotors as Brake devices (22, 75) are provided for the vehicle, UK during at least part of the compression and working strokes the piston in the cylinders to the corresponding cylinder To vent the atmosphere. _ - 2. Brake system according to claim 1, characterized ge characterizing η ο t, da3 it a first control device (44) for completion of the combustion in de ~ a cylinders 'includes a braking period and a second control device (75) to the cylinder v / hile at least parts of Verdien.-' tung - and working strokes of the corresponding pistons v / uring the braking period to bleed. · -. · 3. Brake system according to claim. 1 in connection with a 'cons uniqueness machine, which has a number of inlet valves and contains a series of exhaust valves for the cylinders, characterized in that the ent. ventilation device smock (75th »72, 7C), the -during At least parts of the compression and working strokes of the pistons in the cylinders at least one of the valve rows -. - .- partially keep open. . .. 4. Brake system according to claim 3, characterized geke η η ζ calibrates that the venting device (75, 72, 70) during at least parts of the compression. · - "and working strokes of the pistons in the cylinders, the row of outlet valves (58) at least partially open holds.; BATH ORIGINAL '909885/0999 5. Brake system according to one of claims 1 to 4 for a motor vehicle with a clutch, GE mark not by a device (36) responsive to the clutch (40) and actuation of the venting device (72, 72, 70) when the clutch is disengaged. 6. Brake system according to one of claims 1 to 5 for a motor vehicle with a manual transmission, characterized by a device (38) which is responsive to the transmission (42) and prevents actuation of the venting device (75 , 72, 70) when the Gearbox is in its neutral setting. 7. Brake system according to claim 6, characterized in that it contains a main control (24) which can be moved from a non-braking position into a first position and beyond the first position into a further position (Pig. Ö) and that the ventilation device (75 ', 72, 70) can be actuated as a function of the movement of the main control from the non-braking position into the first position and into the further position. 8. Brake system according to claim 2 in connection with an internal combustion engine with an accelerator pedal movable through a range of positions to different Obtain fuel flow rates to the engine and which can be reset from this range, characterized in that the first and second control devices (44, 75) on reset of the accelerator pedal (24) from this area. ' BATH 90988570999 9. Brake system according to claim 1, wherein the number of cylinders a corresponding row of inlet valves and a has a corresponding row of outlet valves, characterized in that the venting device (75, 72, 70) the closing movements of a of the valve rows (e.g. 5B) against the pressure of the pedals (60) the valve bank can block. 10. Braking system according to claim 9, at dorr; Each valve of the a valve bank normally operated by a cam Rocker arm against the action of the corresponding valve spring is depressed to the open position, thereby characterized in that the blocking device (70) blocks the return movements of the rocker arms (62). 11. Brake system according to claim 10, characterized characterized in that the blocking device has a rotary eccentric (70). 12. Brake system according to claim 1, wherein the cylinders have corresponding exhaust valves which are in communication with an exhaust pipe, characterized in that the first control device (44, 48) terminates the combustion in the cylinders for a Breas period that the second control device (75) d.the outlet valves (58) at least partially during at least parts of the compression and working strokes of the corresponding pistons during the braking period and that a third control device (78, 84) is provided through which the exhaust gas flow can be restricted from the exhaust pipe (34) during the braking period in order to thereby generate a counter pressure in the exhaust pipe . 909885/0999 13. Brake system according to claim 12 in conjunction with a kit Motor vehicle, which has a manual transmission, characterized in that there is a Contains device (33) on the gearbox (42) responds to prevent actuation of the first (44), second (75) and third (70) control devices au, if κ i the gearbox is in its neutral position. 14. Brake system according to claim 13, geke η η ζ eich η et by a main control (24) which is movable from a non-braking position into a first, second and third position (Pig. 5), that the first control device (44; depending on the movement of the main control from the Kichtbremsen-Staltung in the first, second and third position can be actuated that one of the second and third control devices (75, Ί'ό) responds to the movement of the main control in the second and third position and that the other of the second and third control devices is responsive to the movement of the main control into the third position, 15. Brake system according to claim 14, characterized characterized in that the second control device (75) depending on the movement of the main control (24) can be operated in the wide and third positions iot and riaii the third control device (7ö) as a function of the movement the main control (24) is actuated in the third position. 16. Brake system according to claim 14, characterized characterized in that the third control device (78) can be actuated as a function of the movement of the main control (24) into the second and third positions and that the second control device (75) can be actuated as a function of the movement of the main control into the third position is. BADORIQfNAL 909885/0999 17. Br era 3 sys torn according to claim 14, characterized characterized in that the accelerator pedal (24) the Main control forms and that the accelerator pedal from a range can be reset by fuel supply dividers, whereby the first (44), second (75) and third (78) control devices respond to the return of the accelerator pedal. 18. Brake system according to claim 12, g e k en η ζ e i η et by a main control (24), which consists of a Kichtbremsen-Staltung one after the other in a first and second buro position is movable, the first control device (44) depending on the movement of the main control from the Kichtbremsen position can be operated in the first and second positions and the second and third control devices (75, 78) respond to movement of the main control from the no-brake position respond in the second position. 19 · Brake system according to one or more of the preceding claims for a motor vehicle which is driven by an internal combustion engine via a clutch and a transmission, the internal combustion engine having an accelerator pedal and a number of cylinders with corresponding exhaust valves / which are in connection with an exhaust pipe and the internal combustion engine can also be used as an engine brake, geke η η ζ & i ch η e X through the combination of the following features: Iks accelerator pedal Area can be reset to first, second and third retracted positions in a retracted area of stables, the first control device (44, 48) terminates the combustion in the cylinders for. a braking period that; The second control device (75, 72) prevents the exhaust valves (58) from being completely closed during the braking period, the third control device (78, 84) restricts the flow of exhaust gas from the exhaust pipe (34): thereby creating a back pressure ira 909885/099 & ^BAD Exhaust pipe is generated during the braking period, the first control device (44, 48) responds to the return of the accelerator pedal (24) to the retracted range, one of the second and third control devices responds to the return of the accelerator pedal from the first position the . second and third position on _; and the other of the second and third control devices is responsive to the return of the accelerator pedal to the third position. 20. Brake system according to claim 19, characterized in that it contains a device (36), which responds to the clutch, including an actuation % of the first, second and third control devices (44,75,78.) To prevent when the The clutch is disengaged. . 21. Mode of operation of an internal combustion engine of a vehicle to consume energy for a braking process, the internal combustion engine having a number of cylinders, with a corresponding row of inlet valves: and a corresponding row of exhaust valves, characterized by the termination of the combustion in the cylinders for a braking period and opening of the outlets of the corresponding cylinders so that a gaseous medium can flow through these outlets during at least parts of the compression and working strokes of the piston A in the cylinders. 22. Operation according to claim 21, characterized in that the outlets, the cylinder be opened by at least one of the rows of valves is at least partially kept open. 909885/0999 23. Working method according to. Claim. 22, d a d u r c h characterized in that the exhaust valves are partially kept open and that as a further step the From gas flow from the) exhaust pipe during at least one Part of the braking period is limited to one counter pressure to generate in the exhaust pipe. 24. Mode of operation according to one of claims 21 to 23, marked by the fact that the complete Prevent one of the rows of valves from closing during an entire blast period; will. 25. Operation according to claim 24, wherein each valve of the a yenxil row operated by an associated rocker arm becomes, thereby g e k e η η ζ e i c h η e t, that the full return movement of the various rocker arms blocked. · 909885/0999