Method and arrangement for detecting icing in pumps utilized in the diagnosis of tank leakage in motor vehicles
First Claim
1. A method for checking the operability of a tank-venting system of a motor vehicle including checking the tightness thereof, the tank-venting system including a tank, an adsorption filter, a connecting line connecting the adsorption filter to the tank, the adsorption filter having a venting line, a tank-venting valve, a valve line connecting the tank-venting valve to the adsorption filter and a pump module connected to the adsorption filter, the method comprising the steps of:
- operating said pump module from time to time to introduce an overpressure relative to atmospheric pressure into said tank-venting system;
detecting the course of at least one operating characteristic variable of said tank-venting system indicative of the pressure therein when introducing said overpressure;
from said course, drawing a conclusion as to the presence of a non-tightness of said tank-venting system;
outputting a corresponding fault signal when a condition of said non-tightness is present in said tank-venting system;
inducting scavenging air from the ambient of said vehicle and scavenging said adsorption filter with said scavenging air from time to time for regenerating said adsorption filter;
detecting the temperature of said scavenging air and the quantity of said scavenging air supplied to said absorption filter during scavenging of said adsorption filter; and
, drawing a conclusion from at least one of said temperature and said quantity as to whether said pump module is in one of the following states;
frozen, thawed or demoisturized.
1 Assignment
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Accused Products
Abstract
A tank-venting system includes an active charcoal filter (20), which is connected to a tank (10). An intake manifold (40) of an internal combustion engine is connected to a tank-venting valve (30). The active charcoal filter (20) stores fuel vaporized in the tank (10). When the tank-venting valve (30) is driven open by the control unit (60), air from the ambient is drawn by suction through the active charcoal filter (20) and the fuel stored therein is released to the inducted air. A pump (50) is provided for checking the tightness of the tank-venting system and is connected to the control unit (60). A switchover valve (70) is connected downstream of the pump (50). A reference leak (81) is arranged in parallel to the switchover valve (70). A throughflow sensor (90) and a temperature sensor (91) are connected forward of the pump (50) which detect the scavenging air quantity, which is used to scavenge the active charcoal filter (20), as well as the intake air temperature. The sensors transmit the scavenging air quantity and the temperature to the control unit (60). Based on the scavenging air quantity and the intake air temperature, the control unit determines whether the pump (50) is iced at the particular time point. In case of a determination of “iced”, the tightness measurement is not enabled by a control signal and/or the output of a fault signal, which indicates non-tightness of the tank-venting system, is suppressed.
16 Citations
14 Claims
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1. A method for checking the operability of a tank-venting system of a motor vehicle including checking the tightness thereof, the tank-venting system including a tank, an adsorption filter, a connecting line connecting the adsorption filter to the tank, the adsorption filter having a venting line, a tank-venting valve, a valve line connecting the tank-venting valve to the adsorption filter and a pump module connected to the adsorption filter, the method comprising the steps of:
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operating said pump module from time to time to introduce an overpressure relative to atmospheric pressure into said tank-venting system;
detecting the course of at least one operating characteristic variable of said tank-venting system indicative of the pressure therein when introducing said overpressure;
from said course, drawing a conclusion as to the presence of a non-tightness of said tank-venting system;
outputting a corresponding fault signal when a condition of said non-tightness is present in said tank-venting system;
inducting scavenging air from the ambient of said vehicle and scavenging said adsorption filter with said scavenging air from time to time for regenerating said adsorption filter;
detecting the temperature of said scavenging air and the quantity of said scavenging air supplied to said absorption filter during scavenging of said adsorption filter; and
,drawing a conclusion from at least one of said temperature and said quantity as to whether said pump module is in one of the following states;
frozen, thawed or demoisturized.- View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A control unit for carrying out a method for checking the operability of a tank-venting system of a motor vehicle including checking the tightness thereof, the tank-venting system including a tank, an adsorption filter, a connecting line connecting the adsorption filter to the tank, the adsorption filter having a venting line, a tank-venting valve, a valve line connecting the tank-venting valve to the adsorption filter and a pump module connected to the adsorption filter, the control unit comprising:
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means for operating said pump module from time to time to introduce an overpressure relative to atmospheric pressure into said tank-venting system;
means for detecting the course of at least one operating characteristic variable indicative of the pressure of said tank-venting system when introducing said overpressure;
means for drawing a conclusion from said course as to the presence of a non-tightness of said tank-venting system;
means for outputting a corresponding fault signal when a condition of said non-tightness is present in said tank-venting system;
means for operating said pump module for inducting scavenging air from the ambient of said vehicle and scavenging said adsorption filter with said scavenging air from time to time for regenerating said adsorption filter;
sensor means for detecting the temperature of said scavenging air and the quantity of said scavenging air supplied to said absorption filter during scavenging of said adsorption filter with said scavenging air; and
,means for evaluating said temperature and said quantity as to whether said pump module is in one of the following states;
frozen, thawed or demoisturized.- View Dependent Claims (10, 11)
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12. A tank-venting system of a vehicle, the tank-venting system comprising:
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a tank;
an adsorption filter having a venting line;
a connecting line connecting said adsorption filter to said tank;
a tank-venting valve;
a valve line connecting said tank-venting valve to said adsorption filter;
a pump module connected to said adsorption filter for introducing an overpressure in said tank-venting system relative to atmospheric pressure;
means for detecting the course of at least one operating characteristic variable of said tank-venting system indicative of the pressure therein while introducing said overpressure;
means for drawing a conclusion from said course as to the pressure of a non-tightness of said tank-venting system;
means for outputting a corresponding fault signal when a condition of said non-tightness is present in said tank-venting system;
means for operating said pump module for inducting scavenging air from the ambient of said vehicle and scavenging said adsorption filter with said scavenging air from time to time for regenerating said adsorption filter; and
,sensor means for detecting the temperature of said scavenging air and the quantity of said scavenging air supplied to said absorption filter during scavenging of said adsorption filter with said scavenging air. - View Dependent Claims (13, 14)
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Specification