DE102009008831A1 - Internal-combustion engine i.e. petrol internal-combustion engine, has check valves directly arranged at connection points and connected with intake air line, and tank and crankcase ventilation systems connected with connection points - Google Patents

Abstract

The engine i.e. petrol internal-combustion engine (1), has a tank ventilation system (20) and a crankcase ventilation system (21) that are attached at two connection points (30, 31), where the points are placed before a compressor (12) and behind a butterfly valve (14), respectively, at an intake air line (10). Check valves (34, 35) are directly arranged at the connection points, and are undetachably connected with the intake air line. A vent line (29) guides from the tank ventilation system and the crankcase ventilation system to the two connection points. An independent claim is also included for a method for monitoring a tank ventilation system and a crankcase ventilation system of an internal-combustion engine.

Description

The The invention relates to an internal combustion engine according to the The preamble of claim 1, as well as methods for monitoring a tank ventilation system and a crankcase ventilation system an internal combustion engine according to the preamble of claims 10 to 12.

From the DE 103 00 592 A1 already an internal combustion engine of the aforementioned type is known, which has both a tank ventilation system and a crankcase ventilation system. The tank or crankcase ventilation gases discharged from the tank or crankcase ventilation system are sent to combustion by being directed into an intake air line of the internal combustion engine. Both separate between the tank ventilation system and the intake and between the crankcase ventilation system and the intake line there are two separate vent lines, one of which opens in front of the compressor of the exhaust gas turbocharger and the other behind the throttle valve into the intake air line. The two in front of the compressor of the exhaust gas turbocharger in the intake air line opening vent line are used for full load ventilation of the tank or the crankcase, while the opening behind the throttle valve in the intake air vent lines for partial load ventilation of the tank or the crankcase. All vent lines are equipped with valves with an adjustable opening degree.

There a defect of the tank ventilation system and / or the crankcase ventilation system for Escape of unburned hydrocarbons into the environment leads, have been in most states for some time Diagnostic procedures required to help ensure proper functioning the tank ventilation system and the crankcase ventilation system lets diagnose, leaving one to escape unburned hydrocarbons leading to failure recognize and fix it early. About that However, the California Air Resources Board (CARB) is also calling Otto internal combustion engines with turbocharger now also an additional monitoring the discharge points where tank ventilation gases and the crankcase ventilation gases be introduced into the intake air line. This is to prevent Be that as a result of a release of the compounds the connection points to an unwanted emission of unburned hydrocarbons comes into the environment.

While Monitoring the connection point of the tank and crankcase ventilation line or pipes that are behind the throttle in the intake air line open and in suction for supplying the vent gases serve in the intake air line, no problems leaves the junction of the front of the compressor of the exhaust gas turbocharger opening into the intake air line tank and crankcase ventilation line or -leitungen, through which the vent gases in the boost pressure operation into the intake air line, difficult to monitor. This is especially true when the cylinder filling the Internal combustion engine not from the measured values of one in the flow direction the intake air arranged in front of the compressor in the intake air line Air mass meter, but from the readings of a so-called Intake manifold pressure sensor is calculated behind the throttle in a commonly referred to as a suction tube part of Intake air line and thus behind the discharge point of the vent gases in Boost pressure operation is arranged.

in principle it would be possible, the connections the tank and crankcase ventilation lines on the intake air duct as non-detachable connections, which, however, in the case of the need for disassembly problems raises.

From the DE 102 49 720 A1 In addition, a pressure control valve for a crankcase ventilation system of an internal combustion engine is already known, which is arranged between a crankcase and an intake manifold of the internal combustion engine and connected to the intake manifold by two vent lines, one of which before a compressor of an exhaust gas turbocharger and the other behind a throttle valve into the exhaust pipe empties. Each of the two vent lines contains a check valve, both of which are integrated into line ports of the pressure control valve.

outgoing From this, the object of the invention is an internal combustion engine and to provide a method of the type mentioned, which a monitoring of the discharge points of the vent gases allow in the intake air in a relatively simple manner.

These Task is in the internal combustion engine according to the invention solved in that directly at the connection points, where the vent gases introduced into the intake air line are, in each case a check valve is arranged.

The invention is based on the idea that from the DE 102 49 720 A1 known check valves away from the pressure control valve to the system boundaries of the crankcase ventilation system and the tank ventilation system, ie directly to the intake air line to lay. As a result, leakage between the tank ventilation system and the crankcase ventilation system on the one hand and the intake air line on the other hand without additional Liche measures are monitored with a pressure sensor which is located in the intake air behind the throttle and is used to determine a cylinder filling, however, are also advantageously used to monitor the discharge points of the vent gases from the tank ventilation system and the crankcase ventilation system in the intake air in suction and boost pressure operation can.

Around the number of components required and the installation effort low, sees a preferred embodiment of the invention before that the tank ventilation system and the crankcase ventilation system at the two connection points together to the intake air line are connected.

there can with the help of the pressure sensor both a leakage between the Tank ventilation system and the crankcase ventilation system on the one hand and the intake air line on the other hand, as well as a defect or Clamp one directly at the junction before the compressor arranged open check valve diagnosed or detected be, while a defect or jamming of the at the junction behind the throttle arranged closed check valve advantageous in the course of a monitoring or diagnosis of a Tank ventilation valve of the tank ventilation system is detected.

While to facilitate the exchange behind at the junction the throttle valve arranged check valve solvable with the intake air line and a tank ventilation system and leading to the crankcase ventilation system The vent line can be connected to the at the Connection point upstream of the compressor arranged check valve according to a preferred embodiment of the invention permanently connected to the intake air line. This can on the one hand, beyond this check valve not more to a release of the connection between the tank ventilation system and the crankcase ventilation system on the one hand and the intake air duct, on the other hand. On the other hand in the case of a pressure exceeding the ambient pressure in the vent line an outlet of unburned th hydrocarbons be prevented in the environment. However, this check valve can releasably connected to the vent line, so these in case of a line break from the check valves can be solved and replaced.

If this is located at the junction behind the throttle Check valve from the intake air line and to the Tank ventilation system and the crankcase ventilation system leading vent line triggers, or if that is located at the junction in front of the compressor Non-return valve releases from the vent line, Immediately creates an ambient pressure in the vent line a, which allows detection of the leakage.

in the The following is the invention with reference to an illustrated in the drawing Embodiment explained in more detail. Show it:

1 a schematic representation of parts of an internal combustion engine with an exhaust gas turbocharger, a tank ventilation system and a crankcase ventilation system;

2 a representation of the pressure in the intake air pipe in front of the compressor of the exhaust gas turbocharger and behind a throttle valve in dependence on the load and speed of the internal combustion engine.

1 shows a schematic sectional view of parts of a supercharged gasoline engine 1 with an engine block 2 , one the crankshaft 3 and a crank room 4 the internal combustion engine 1 surrounding crankcase 5 , as well as at least one piston 6 that has a connecting rod 7 with the crankshaft 3 is connected and in an associated cylinder 8th of the motor 1 moved up and down. The combustion of the fuel-air mixture in a combustion chamber 9 of the cylinder 8th required air is the combustion chamber 9 through an intake air line 10 fed to an air filter 11 , a compressor 12 an exhaust gas turbocharger 13 and a throttle 14 contains. The throttle 14 is in the flow direction of the air behind the compressor 12 and in front of you usually as a suction tube 15 designated part of the intake air line 10 arranged. The combustion air from the combustion chamber 9 of the cylinder 8th is through an exhaust manifold 16 and an exhaust pipe 17 dissipated, which is a turbine 18 the exhaust gas turbocharger 13 contains. To fill the cylinder 8th or in the cylinder 8th to determine the supplied air mass is behind the throttle 14 in the intake manifold 15 a pressure sensor 19 provided for measuring the intake manifold pressure, from which then the air mass is calculated according to the relationship p · V = m · R · T.

To prevent emission of unburned hydrocarbons into the environment, the internal combustion engine includes 1 continue a tank ventilation system 20 and a crankcase ventilation system 21 ,

With the tank ventilation system 20 can be a fuel tank 22 the internal combustion engine 1 vented and removed from the fuel tank 22 discharged fuel vapors or tank vent gases for combustion in the cylinder 8th into the intake air line 10 Trains be led. The tank ventilation system 20 includes one with the fuel tank 22 communicating activated carbon filled fuel vapor storage tanks 23 in which the fuel vapors or tank vent gases are cached, and a regeneration line 24 by which to regenerate the activated carbon air from the environment through the storage tank 23 into the intake air line 10 is sucked when a between the storage tank 23 and the intake air line 10 arranged tank vent valve 25 is opened.

With the crankcase ventilation system 21 can the crankcase 4 the internal combustion engine 1 be actively vented by selectively injecting air into the crankcase 5 is supplied and by the crankcase ventilation gases, ie the supplied, with oil mist from the crankcase 4 mixed air and the so-called blow-by gases, ie during operation of the internal combustion engine 1 between cylinders 8th and pistons 6 passing combustion gases, also for combustion in the intake air line 10 be supplied. The crankcase ventilation system 21 includes one with the crankcase 4 communicating oil separator 26 and one between the oil separator 26 and the intake air line 10 arranged pressure control valve 27 ,

To monitor the proper functioning of the tank ventilation system 20 and the crankcase ventilation system 21 serves a diagnostic module 28 That with the tank vent valve 25 , the pressure control valve 27 and the pressure sensor 19 connected is.

The tank vent valve 25 of the tank ventilation system 20 and the pressure control valve 27 of the crankcase ventilation system 21 are through a common vent line 29 with the intake air line 10 connected. This vent line 29 is with its one end at a first junction 30 behind the air filter 11 and in front of the compressor 12 and with its opposite end at a second junction 31 behind the throttle 14 to the intake air line 10 connected and communicates between the two ends via two branches 32 and 33 with the tank vent valve 25 of the tank ventilation system 20 or the pressure control valve 27 of the crankcase ventilation system 21 so that the vent line 29 from the tank ventilation system 20 and the crankcase ventilation system 21 shared.

Immediately at the two connection points 30 and 31 is each a check valve 34 and 35 arranged, the entry of air from the intake air line 10 in the common vent line 29 prevent. On the one hand, this ensures that there is no air at the compressor 12 and at the throttle 14 past the vent line 29 can flow and prevents, on the other hand, that air from the intake air line 10 through the vent line 29 and the branches 32 or 33 in the tank ventilation system 20 or the crankcase ventilation system 21 can get. The check valve 34 at the first junction 30 is insoluble with the intake air line 10 and detachable with the one end of the vent line 29 connected while the check valve 35 at the second junction 31 detachable with the intake air line 10 and the opposite end of the vent line 29 can be connected.

In boost pressure operation of the exhaust gas turbocharger 13 become the tank and crankcase ventilation gases due to the pressure conditions in the intake air line 10 and in the vent line 29 at the first junction 30 through the open check valve 34 through into the intake air line 10 while in suction mode at the second connection point 31 through the open check valve 35 through into the intake air line 10 be initiated.

As in 1 is a pressure p1 in the intake air line 10 in front of the compressor 12 less than or equal to the ambient pressure p_Environment, while a pressure p2 in the intake air line 10 behind the compressor 12 and in front of the throttle 14 is equal to the sum of the pressures p1 + p_load, where p_load is the boost pressure of the compressor 12 is. The pressure p3 in the intake manifold 15 behind the throttle 14 is equal to the difference of the pressures p2 - p_Drossel, where p_Drossel is the pressure loss at the throttle 14 is.

2 shows the relationship between p1 and p3 depending on the load and the speed of the internal combustion engine 1 , where the area I the relationship in suction mode and the area II the relationship in the boost pressure mode reflects.

The pressure in the vent line 29 is referred to as p4 and corresponds to the respective lower pressure of p1 and p3, since both in the suction mode and in the boost pressure mode each one of the two check valves 34 . 35 is open. On the other hand, this means that apart from the special case p1 = p3 always one of the two check valves 34 . 35 must be closed.

Inside the crankcase 4 is from the pressure control valve 27 a low negative pressure is set, ie a pressure which is slightly below the ambient pressure p_Environment. This pressure control by the pressure control valve 27 is required because z. B. in idle mode, a pressure p4 ≈ p3 sets, which is about 300 mbar absolute, which is idle for the crankcase 4 much too low would.

The tight connection between the check valve 34 and the intake air line 10 is required in case of disconnecting the connection at the first connection point 30 a discharge of vent gases from the vent line 29 into the environment when in pressure boost operation, the pressure p4 in the vent line 29 is higher than the ambient pressure p_Environment.

When the vent line 29 has a leak that can occur anywhere, for example, by a breakage of the vent line 29 or by loosening the connection between the vent line 29 and one of the two check valves 34 . 35 , the pressure p4 is inside the vent line 29 equal to the ambient pressure p_Environment. Because in this state tank or crankcase ventilation gases from the vent line 29 can escape into the environment, such a condition must be detected by the diagnosis. This is also the case with the described tank and crankcase ventilation system because either the idle speed is too high in the suction mode and can not be adjusted because of the supply of too much fresh air into the intake manifold because the intake manifold pressure measured for charge balancing is proportional to the position of the throttle 14 is implausible or the diagnosis of the tank ventilation leads to a detection of the leakage.

If the check valve 34 stuck in its open position, the pressure p4 within the vent line 29 equal to the pressure p1. This causes the air in the boost pressure operation from the environment through the check valve 34 is sucked, resulting in a slightly smaller leakage current into the intake manifold 15 but that of the pressure sensor 19 detected pressure p3 in the intake manifold 15 also increases and makes a detection of the leakage possible.

If the check valve 34 stuck in its closed position, this is alone with the help of the pressure sensor 19 not diagnosable. In such a case, however, the vent gases from the tank ventilation system 20 and the crankcase ventilation system 21 during suction operation at the second connection point 31 through the check valve 35 through the intake manifold 15 supplied when the pressure p4 is greater than the pressure p3.

If the check valve 35 stuck in its closed position, this may be due to a diagnosis of the tank vent valve 25 be recognized, which leads to an improvement over known systems with respect to the crankcase ventilation.

1

Internal combustion engine

2

block

3

crankshaft

4

crankcase

5

crankcase

6

piston

7

pleuel

8th

cylinder

9

combustion chamber

10

intake air line

11

air filter

12

compressor

13

turbocharger

14

throttle

15

suction tube

16

exhaust manifold

17

exhaust pipe

18

turbine

19

pressure sensor

20

Tank ventilation system

21

Crankcase ventilation system

22

Fuel tank

23

storage container

24

regenerating line

25

Tank ventilation valve

26

oil separator

27

Pressure control valve

28

diagnostic module

29

common vent line

30

first junction

31

second junction

32

junction

33

junction

34

check valve

35

check valve

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• DE 10300592 A1 [0002]
• - DE 10249720 A1 [0006, 0009]

Claims (12)

Internal combustion engine with an intake air line, which includes a compressor of an exhaust gas turbocharger and a throttle valve, and with a tank ventilation system and a crankcase ventilation system, which are connected at two connection points in front of the compressor and behind the throttle valve to the intake air line, characterized in that directly at the connection points ( 30 . 31 ) each a check valve ( 34 . 35 ) is arranged. Internal combustion engine according to claim 1, characterized in that the tank ventilation system ( 20 ) and the crankcase ventilation system ( 21 ) together at the two connection points ( 30 . 31 ) to the intake air line ( 10 ) are connected. Internal combustion engine according to claim 1 or 2, characterized by a tank ventilation system ( 20 ) and the crankcase ventilation system ( 21 ) to the two connection points ( 30 . 31 ) leading vent line ( 29 ). Internal combustion engine according to one of the preceding claims, characterized in that the at the junction ( 30 ) in front of the compressor ( 12 ) arranged check valve ( 34 ) unsolvable with the intake air line ( 10 ) connected is. Internal combustion engine according to claim 4, characterized in that the check valve ( 34 ) detachable with a tank venting system ( 20 ) and the crankcase ventilation system ( 21 ) to the two connection points ( 30 . 31 ) leading vent line ( 29 ) connected is. Internal combustion engine according to one of the preceding claims, characterized in that the at the junction ( 31 ) behind the throttle ( 14 ) arranged check valve ( 35 ) detachable with the intake air line ( 10 ) and one from the tank ventilation system ( 20 ) and the crankcase ventilation system ( 21 ) to the two connection points ( 30 . 31 ) leading vent line ( 29 ) connected is. Internal combustion engine according to one of claims 3 to 6, characterized in that the tank ventilation system ( 20 ) with the vent line ( 29 ) connected tank vent valve ( 25 ). Internal combustion engine according to one of claims 3 to 7, characterized in that the crankcase ventilation system ( 21 ) with the vent line ( 29 ) connected pressure control valve ( 27 ). Internal combustion engine according to one of the preceding claims, characterized by a behind the throttle valve ( 14 ) in the intake air line ( 10 ) arranged pressure sensor ( 19 ) for determining a cylinder filling. Method for monitoring a tank ventilation system and a crankcase ventilation system of an internal combustion engine, which are connected at two connection points in front of a compressor of an exhaust gas turbocharger and behind a throttle valve to an intake air line of the internal combustion engine, characterized in that a leakage between the tank ventilation system ( 20 ) and the crankcase ventilation system ( 21 ) on the one hand and the intake air line ( 10 ) on the other hand by monitoring the pressure (p3) behind the throttle valve ( 14 ) is detected. Method for monitoring a tank ventilation system and a crankcase ventilation system of an internal combustion engine, which are connected at two connection points in front of a compressor of an exhaust gas turbocharger and behind a throttle valve via check valves to an intake air line of the internal combustion engine, characterized in that a defect or jamming of the at the junction ( 30 ) in front of the compressor ( 13 ) arranged open check valve ( 34 ) by monitoring the pressure (p3) behind the throttle valve ( 14 ) is detected. Method for monitoring a tank ventilation system and a crankcase ventilation system of an internal combustion engine, which are connected at two connection points in front of a compressor of an exhaust gas turbocharger and behind a throttle valve via check valves to an intake air line of the internal combustion engine, characterized in that a defect or jamming of the at the junction ( 31 ) behind the throttle ( 14 ) arranged closed check valve ( 35 ) by a diagnosis of a tank ventilation valve ( 25 ) of the tank ventilation system ( 20 ) is detected.