JPH0815213A - Control device for oxygen sensor with heater - Google Patents

Abstract

PURPOSE:To use a system where an oxygen sensor with a heater is disposed even downstream from a catalytic converter, by preventing the breakage of oxygen sensor elements easily and surely and always making such an optimum condition that a function as the oxygen sensor can satisfactorily be fulfilled. CONSTITUTION:The temperature of an internal combustion engine exhaust pipe 7 is estimated according to the intake air quantity detected by an air flow meter 2. On condition that the estimated temperature reaches a temperature which corresponds to a moisture non-generating temperature of the exhaust pipe 7, an electric current is applied to the heater of an oxygen sensor 14 with a heater disposed on the downstream side of a catalytic converter 8. On the other hand, according to the condition of an idle switch 11, the idle time is detected, and on condition that the idle time continues during designated time having some fear of generating moisture to the exhaust pipe 7, a temperature estimated value is reset, and application of an electric current to the heater of the oxygen sensor 14 with a heater is cancelled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heater oxygen sensor management device for managing the state of a heater oxygen sensor arranged downstream of a catalytic converter in an internal combustion engine exhaust system, and more particularly to a heater for the oxygen sensor. The present invention relates to the realization of a device which is effective in easily managing the energization condition or the use condition.

[0002]

2. Description of the Related Art Generally, an oxygen sensor for detecting the oxygen concentration in exhaust gas of an internal combustion engine has a limited operating temperature, and does not operate normally at a low temperature of 400 ° C. or lower.

Therefore, in a situation where the exhaust gas temperature is lowered, such as when the internal combustion engine is warmed up after a low temperature start or is in an idling state for a long time, various controls based on the detected value of the oxygen sensor. The reliability of is also extremely low.

Therefore, conventionally, in order to eliminate such inconvenience of the oxygen sensor, a so-called heater-equipped oxygen sensor having a structure in which a sensor element of the oxygen sensor is heated by a heater and the temperature is kept at 400 ° C. or higher is often used. ing.

In such an oxygen sensor with a heater, the activation temperature of the sensor element is set to the above 4 by constantly energizing the heater or at a low temperature.
A temperature of 00 ° C or higher will be secured.

On the other hand, such an oxygen sensor is usually arranged at a position near the fuel chamber of the exhaust system of the internal combustion engine, that is, upstream of the catalytic converter, for the convenience of being used for feedback control of the air-fuel ratio.

However, even if the sensor is equipped with the above-mentioned heater, there are variations in its output characteristics, deterioration over time, and secular deterioration. There is a decline over time. The variation and deterioration of the output characteristics of the oxygen sensor, the reduction of the purification rate of the catalytic converter, and the like are factors that impair the control accuracy of the air-fuel ratio feedback control and the compliance with exhaust gas regulations.

Therefore, in recent years, an oxygen sensor is also provided on the downstream side of the catalytic converter, and the oxygen sensor on the downstream side of the catalytic converter compensates for variations and deterioration of the output characteristics of the oxygen sensor on the upstream side of the catalytic converter. A system has been proposed that diagnoses a reduction in purification rate of a catalytic converter.

[0009]

According to such a system, the control accuracy of the feedback control of the air-fuel ratio is surely guaranteed and the compliance with the exhaust gas regulation is maintained well.

On the other hand, however, by adopting such a so-called double oxygen sensor system, the following inconveniences have been newly exposed. That is, even in the oxygen sensor on the downstream side of the catalytic converter, an oxygen sensor with a heater is used to ensure its reliability, and the heater is energized at all times or at low temperature. Especially in the oxygen sensor on the downstream side of this catalytic converter: -Water droplets accumulated in the exhaust pipe or in the catalytic converter when the engine is stopped. -Water droplets that have condensed after the exhaust gas has touched the cold exhaust pipe after the engine has started cold. And the like come into contact with the heated sensor element, which may cause the element to crack due to thermal shock.

Conventionally, in order to prevent such cracking of the oxygen sensor element, for example, as seen in Japanese Utility Model Laid-Open No. 5-84552, (1) the temperature of the exhaust pipe of the engine and the element temperature of the oxygen sensor are set to the respective temperatures. Measure with a sensor. (2) The energization of the heater is controlled on / off according to the measured temperature. Specifically, when the element temperature is lower than 330 ° C. and the exhaust pipe temperature is higher than 100 ° C., the heater is turned on, and the element temperature is 330 ° C. or higher, and
The energization is turned off on condition that the exhaust pipe temperature is 100 ° C. or lower. Although an apparatus for executing such energization control has been proposed, it still leaves a problem in terms of practicality.

That is, in the device described in the above publication, the temperature sensor must be provided, and an increase in cost in constructing the device cannot be avoided. In addition, in the same device, on / off of energization is frequently repeated in the vicinity of the respective boundary temperatures based on the element temperature and the exhaust pipe temperature. That is, there is a concern that the function as the oxygen sensor may not be fully fulfilled because the control becomes complicated. Incidentally, although it is an oxygen sensor with a heater, there is usually a response delay from the start of energization of the heater to the activation of the sensor, and normal oxygen concentration detection is performed immediately after energization of the heater. Not necessarily.

The present invention has been made in view of the above circumstances, and it is a system in which an oxygen sensor with a heater is arranged on the downstream side of a catalytic converter, and the element cracking of the oxygen sensor can be easily and surely prevented. Moreover, it is an object of the present invention to provide a management device for an oxygen sensor with a heater, which can be used in a preferable state in which the function as the oxygen sensor is sufficiently fulfilled.

[0014]

In order to achieve such an object, according to the invention of claim 1, there is provided an apparatus for managing the state of an oxygen sensor with a heater arranged on the downstream side of the catalytic converter. Load calculating means for calculating the load, time integrating means for integrating the time during which the calculated load is equal to or greater than a predetermined value, and a predetermined time corresponding to the predetermined time corresponding to the moisture non-occurrence temperature of the internal combustion engine exhaust pipe. The oxygen sensor heater is energized on the condition that the time is reached.

According to a second aspect of the present invention, there is provided a device for managing the state of the oxygen sensor with a heater arranged on the downstream side of the catalytic converter, and load calculating means for calculating the load of the internal combustion engine, and the load calculating means. A load amount integrating means for integrating the load amount when the calculated load is equal to or more than a predetermined value, and the integrated load amount reaching a predetermined load amount corresponding to the moisture non-generation temperature of the internal combustion engine exhaust pipe. The condition includes an energization control unit that energizes the heater of the oxygen sensor.

In the invention according to claim 3, in the structure of the invention according to claim 1 or 2, idle determining means for performing idle determination of the internal combustion engine, and the idle determination time continues for a predetermined time. On the condition that the above condition is satisfied, an energization cancellation control means for resetting the integrated value and deenergizing the heater of the oxygen sensor is further provided.

According to a fourth aspect of the present invention, there is provided a device for managing the state of the oxygen sensor with a heater arranged downstream of the catalytic converter, and load calculating means for calculating the load of the internal combustion engine. An up / down timer that counts up when the calculated load is equal to or greater than a predetermined value and downcounts when the load is less than a predetermined value, and a predetermined value that corresponds to the moisture non-generation temperature of the internal combustion engine exhaust pipe. The heater of the oxygen sensor is energized on the condition that the value of the oxygen sensor is reached, and the energization control means for canceling the energization of the heater of the oxygen sensor on the condition that the timer value is less than the predetermined value. It will be configured.

According to a fifth aspect of the present invention, in the configuration of the fourth aspect of the invention, the up / down timer is Up when the up count value is Up and the down count value is Down. > Each count value is set in the relationship of Down.

According to a sixth aspect of the present invention, in the configuration of the above-mentioned respective aspects of the present invention, an energization time measuring means for measuring the energization time of the oxygen sensor on condition that the heater of the oxygen sensor is energized, An activity management means for permitting the use of the oxygen sensor is provided on the condition that the measured time is equal to or longer than a predetermined time corresponding to the activation temperature of the oxygen sensor.

Further, in the invention according to claim 7, particularly in the configuration of the invention according to claim 1 or 3, the heater of the oxygen sensor is energized and the time accumulated by the time accumulating means is calculated. The oxygen sensor is configured to further include activity management means for permitting the use of the oxygen sensor on condition that the oxygen sensor is at a predetermined time or longer corresponding to the activation temperature of the oxygen sensor.

According to the invention of claim 8, in particular, in the configuration of the invention of claim 2 or 3, the heater of the oxygen sensor is energized and the load accumulated by the load amount accumulating means. It is configured to further include activity management means for permitting the use of the oxygen sensor on condition that the amount is equal to or more than a predetermined load amount corresponding to the activation temperature of the oxygen sensor.

According to a ninth aspect of the present invention, in the configuration of the fourth or fifth aspect of the invention, the heater of the oxygen sensor is energized and the count value of the up / down counter is the oxygen. The oxygen management device further comprises an activity management means for permitting the use of the oxygen sensor on condition that the oxygen temperature is equal to or higher than a predetermined value corresponding to the activation temperature of the sensor.

According to a tenth aspect of the present invention, in each of the configurations of the first to ninth aspects of the invention, the load of the internal combustion engine is an intake air amount to the internal combustion engine, and the load calculating means. Is the intake air amount calculating means for calculating the intake air amount each time.

Further, in the invention of claim 11, in each of the configurations of the inventions of claims 1 to 9, the load of the internal combustion engine is a basic fuel injection amount to the internal combustion engine, and the load calculating means. Is a basic fuel injection amount calculation means for calculating the value of the basic fuel injection amount each time.

According to the twelfth aspect of the present invention, also in each of the configurations of the first to ninth aspects, the load of the internal combustion engine is the intake air pressure to the internal combustion engine, and the load calculating means. Is the intake air pressure calculating means for calculating the value of the intake air pressure each time.

According to the thirteenth aspect of the present invention, there is provided a device for managing the state of the oxygen sensor with a heater arranged on the downstream side of the catalytic converter, and load calculating means for calculating the load of the internal combustion engine, and this calculation. Time integration means for integrating the time when the load is equal to or more than a predetermined value, and the use of the oxygen sensor is permitted on the condition that the integrated time reaches a predetermined time corresponding to the activation temperature of the oxygen sensor. It is configured to include management means.

According to a fourteenth aspect of the present invention, there is provided a device for managing the state of the oxygen sensor with a heater arranged downstream of the catalytic converter, comprising load calculating means for calculating the load of the internal combustion engine, and the load calculating means. The load amount accumulating means for accumulating the load amount when the calculated load is equal to or more than a predetermined value and the condition that the accumulated load amount reaches a predetermined load amount corresponding to the activation temperature of the oxygen sensor. And a management means for permitting the use of the oxygen sensor.

[0028] According to the fifteenth aspect of the present invention, in the configuration of the thirteenth or fourteenth aspect of the present invention, idle determining means for performing idle determination of the internal combustion engine and a time during which the idle determination is made are predetermined. A prohibition means for resetting the integrated value and prohibiting the use of the oxygen sensor is provided on the condition that the time is continued.

According to the sixteenth aspect of the present invention, there is provided a device for managing the state of the oxygen sensor with a heater arranged downstream of the catalytic converter, comprising load calculating means for calculating the load of the internal combustion engine, and the load calculating means. An up / down timer that counts up when the calculated load is equal to or more than a predetermined value and downcounts when the load is less than a predetermined value, and the timer value is set to a predetermined value corresponding to the activation temperature of the oxygen sensor. Allowed to use the oxygen sensor on the condition that it reaches
A management means for prohibiting the use of the oxygen sensor is provided on condition that the timer value is less than the predetermined value.

According to a seventeenth aspect of the present invention, in the configuration of the above-described sixteenth aspect of the present invention, the up / down timer is set to Up when the up count value is Up and the down count value is Down. > Each count value is set in the relationship of Down.

In the eighteenth aspect of the invention, in each of the configurations of the thirteenth to seventeenth aspects of the invention, the load of the internal combustion engine is an intake air amount to the internal combustion engine, and the load calculating means is The intake air amount calculation means calculates the intake air amount each time.

According to a nineteenth aspect of the present invention, in each of the configurations according to the thirteenth to seventeenth aspects, the load of the internal combustion engine is a basic fuel injection amount into the internal combustion engine,
It is assumed that the load calculating means is a basic fuel injection amount calculating means for calculating a value of the basic fuel injection amount each time.

According to the twentieth aspect of the present invention, the load of the internal combustion engine is the intake air pressure to the internal combustion engine, and the load calculation means is also present in each of the configurations of the thirteenth to seventeenth aspects. Is the intake air pressure calculating means for calculating the value of the intake air pressure each time.

[0034]

It has been confirmed by experiments by the inventor that the temperature of the exhaust pipe of the internal combustion engine has a strong correlation with the load state of the engine.

Further, since this exhaust pipe is usually disposed under the vehicle, even when the engine is in operation, it is naturally cooled by the outside air at the time of idling, and its temperature is also leveled or naturally dropped. It has also been confirmed.

Therefore, according to the invention described in claim 1 or 3, by appropriately calculating the load of the internal combustion engine and integrating the time when the calculated load is equal to or more than a predetermined value,
In particular, the temperature of the exhaust pipe can be easily estimated without using a temperature sensor or the like.

For this reason, the heater of the oxygen sensor is energized on condition that the integrated time by the energization control means reaches a predetermined time corresponding to the moisture non-generation temperature of the exhaust pipe. The heating of the sensor element is performed in a safe state where the above-mentioned water droplets and the like do not touch the element section.

Further, according to the invention as set forth in claim 3, if the power supply to the heater is released through the power supply release control means on condition that the idle time is continued for a predetermined time, the exhaust gas is discharged. The sensor is also cooled before the tube is cooled and the water droplets and the like described above are generated there.

Therefore, also in this case, the safety of the oxygen sensor can be secured without causing the above-mentioned thermal shock. According to such an energization control method for the heater, there is no concern that the energization of the heater will be frequently turned on / off, so that the heater also functions as an oxygen sensor arranged on the downstream side of the catalytic converter. During that time, it will be fully fulfilled.

Incidentally, unlike the oxygen sensor arranged upstream of the catalytic converter, the oxygen sensor arranged downstream of the catalytic converter is not directly used for air-fuel ratio feedback control or the like. , The heater does not need to be energized at all times. It is only necessary to be able to compensate for the variation and deterioration of the output characteristics of the oxygen sensor on the upstream side of the catalytic converter, or to diagnose a reduction in the purification rate of the catalytic converter, etc., during steady running of the vehicle.

It should be noted that the moisture non-generation temperature in the exhaust pipe is about 70 ° C. or higher, and the duration of the idle time is about 3 when there is a concern that moisture will be generated in the exhaust pipe.
It was also confirmed by the above experiment by the inventor that it is 0 minutes.

In addition to the deenergization of the heater,
By resetting the integration time of the time integration means, the exhaust pipe temperature estimation information when the heater is energized again becomes appropriate.

On the other hand, according to the invention of claim 2 or 3, the time integrating means is replaced with a load amount integrating means for integrating the load amount when the calculated load is equal to or more than a predetermined value. You can also

By directly integrating the load amount in this way, it becomes possible to more accurately estimate the moisture non-generation temperature of the exhaust pipe. In this case, as described above, the energization control means: The heater of the oxygen sensor is provided on the condition that the integrated load amount reaches a predetermined load amount corresponding to the moisture non-generating temperature of the exhaust pipe. Energize. And the claim 3 as well.
The energization cancellation control means described is as follows: on condition that the idle determination time continues for a predetermined time, the integrated load amount of the load amount integrating means is reset, and the heater of the oxygen sensor is energized. To release. Will be things.

Further, according to the invention as set forth in claim 4, the time integrating means or the load amount integrating means are up-counted when the calculated load is equal to or more than a predetermined value, and the load is predetermined. Up / down timer that counts down when it is less than the value. For the energization control means and the de-energization control means, energize the heater of the oxygen sensor on the condition that the timer value reaches a predetermined value corresponding to the moisture non-generation temperature of the exhaust pipe, An energization control unit that deenergizes the heater on the condition that the timer value is less than the predetermined value. To
Each can be replaced.

With such a configuration as well, the oxygen sensor with a heater disposed downstream of the catalytic converter can be safely heated and cooled based on the estimation of the exhaust pipe temperature without using a temperature sensor or the like. be able to.

Further, particularly in such a configuration, as in the invention according to claim 5, the up count value Up of the up / down timer is changed to the down count value Do.
Setting the value larger than wn is effective in increasing the exhaust pipe temperature estimation sensitivity when the heater is energized, and in reducing the ON / OFF frequency of the heater energization. With such a count value setting, even in the configuration of the invention according to claim 4, the function as the oxygen sensor arranged on the downstream side of the catalytic converter described above is sufficiently fulfilled during the activation period. Will be

Further, according to the invention as set forth in claim 6, in each of the configurations of these inventions: an energizing time measuring means for measuring the energizing time of the oxygen sensor on condition that the heater of the oxygen sensor is energized; If the timed time is more than a predetermined time corresponding to the activation temperature of the oxygen sensor and the activity management means for permitting the use of the oxygen sensor is provided, the heater can be provided. The use of the oxygen sensor is prohibited during the period in which there is a delay in response until the oxygen sensor is activated after the current is applied.

Therefore, by using the oxygen sensor arranged on the downstream side of the catalytic converter, it is possible to correct the variation or deterioration of the output characteristic of the oxygen sensor on the upstream side of the catalytic converter, or diagnose the deterioration of the purification rate of the catalytic converter. Even if it is performed, the accuracy required for the correction and the diagnosis can be appropriately secured. That is, the oxygen sensor can be used in an optimum state where the function as the oxygen sensor is sufficiently fulfilled.

According to the invention of claim 7,
Particularly, in the configuration of the invention described in claim 1 or 3, the heater of the oxygen sensor is energized, and the time accumulated by the time accumulating means is equal to or longer than a predetermined time corresponding to the activation temperature of the oxygen sensor. If the activity management means for permitting the use of the same sensor is provided, or according to the invention of claim 8, particularly in the configuration of the invention of claim 2 or 3, If the heater of the oxygen sensor is energized and the load amount integrated by the load amount integrating means is equal to or higher than a predetermined load amount corresponding to the activation temperature of the oxygen sensor, the sensor is used. If the activity management means for permitting the above is further provided, the minimum temperature of each element is added based on the configuration of the invention according to claim 1, 2 or 3, and the activation temperature of the oxygen sensor is directly estimated. In the form of, it is possible to manage the presence or absence of activity of the sensor.

Therefore, according to this structure, the sixth aspect is provided.
It is also possible to make the “use in an optimal state where the function as the oxygen sensor is sufficiently fulfilled” described above with respect to the described invention more accurate.

Experiments by the inventor have confirmed that the element temperature of the oxygen sensor also has a strong correlation with the load state of the internal combustion engine. Further, according to the invention of claim 9, in the configuration of the invention of claim 4 or 5, the heater of the oxygen sensor is energized, and the count value of the up / down counter is the The activity control means for permitting the use of the oxygen sensor on condition that the temperature is equal to or higher than a predetermined value corresponding to the activation temperature of the oxygen sensor, and the configuration of the invention according to claim 4 or 5 is further provided. However, by adding the minimum elements based on its configuration, and by directly estimating the activation temperature of the oxygen sensor,
It becomes possible to manage whether or not the sensor is active.

Also in this case, the "use in an optimum state where the function as the oxygen sensor is sufficiently fulfilled" described above with respect to the invention described in claim 6 can be made more accurate.

Further, in each of the configurations of the inventions according to claims 1 to 9, as the load of the internal combustion engine having a strong correlation with the exhaust pipe temperature or the element temperature of the oxygen sensor, the intake air amount to the engine is set. , Basic fuel injection amount and intake air pressure (intake manifold pressure).

Therefore, as each of the load calculating means, according to the invention of claim 10, an intake air amount calculating means for calculating a value of the intake air amount each time. Alternatively, as in the invention according to claim 11, a fuel basic injection amount calculation means for calculating a value of the fuel basic injection amount each time. Further, according to the invention of claim 12, an intake air pressure calculating means for calculating a value of the intake air pressure each time. By using, it becomes possible to easily and accurately estimate the exhaust pipe temperature or the element temperature of the oxygen sensor through each of these means.

By the way, as the oxygen sensor with a heater, the oxygen sensor with a standard heater is used so that the heater is always energized (mainly when it is used as an oxygen sensor on the upstream side of the catalytic converter) or selectively at low temperature. In addition to the sensor, there is an oxygen sensor with a low power heater.

In the oxygen sensor with the low power heater, the element temperature is maintained at a low temperature of, for example, less than 400.degree. In an environment in which the same water droplets do not occur, the oxygen sensor is of a type that is constantly energized with its heater power adapted so that the element temperature is maintained at a high temperature of 400 ° C. or higher. That is, in the case of the same sensor, on / off control of energization to the heater is not required.

On the other hand, even in the case of such an oxygen sensor with a low power heater, the element temperature thereof is, for example, 40 when the idle state is changed to the steady running state.
From the low temperature of less than 0 ° C. to the activation temperature (high temperature of 400 ° C. or higher), a predetermined response delay still occurs.

The invention described in the thirteenth and subsequent aspects has a configuration particularly effective for managing the state of the oxygen sensor with a low power heater used as the oxygen sensor on the downstream side of the catalytic converter. Have

First, as described above, the element temperature of the oxygen sensor also has a strong correlation with the load state of the internal combustion engine. In addition, since this oxygen sensor is also normally attached to the exhaust pipe and is disposed under the vehicle, even when the engine is in operation, it is naturally cooled by the outside air during idling. The temperature is flat or drops naturally.

Therefore, according to the invention described in claim 13 or 15, by appropriately calculating the load of the engine and integrating the time when the calculated load is equal to or more than a predetermined value,
Also in this case, the element temperature of the oxygen sensor can be easily estimated without using a temperature sensor or the like.

Therefore, for this reason, through the above management means,
If the use of the integrated time is allowed on the condition that a predetermined time corresponding to the activation temperature of the oxygen sensor is reached, even if the response delay occurs in the oxygen sensor, Through the direct estimation of the activation temperature, it becomes possible to determine the optimum state in which the function as the oxygen sensor is sufficiently fulfilled, and to utilize it in the optimum state.

Further, according to the invention as set forth in claim 15, if the use of the oxygen sensor is prohibited by the prohibiting means on condition that the idle time is continued for a predetermined time, the sensor is cooled thereafter. Thus, the use thereof can be prohibited before the device temperature reaches the inactive temperature (low temperature of less than 400 ° C.).

Therefore, in this case as well, it is possible to favorably prevent the oxygen sensor from being used in an inactive state, and consequently, to correct the variation or deterioration of the output characteristics of the oxygen sensor upstream of the catalytic converter, or to use the catalytic converter. It is possible to preferably ensure the accuracy required for the diagnosis such as the reduction of the purification rate.

According to the invention of claim 15, the use of the oxygen sensor is prohibited, and the integrated time of the time integrating means is reset, so that the use of the oxygen sensor is permitted again. The element temperature estimation information at the time of performing is also optimized.

Further, according to the invention of claim 14 or 15, the time integrating means is replaced with load amount integrating means for integrating the load amount when the calculated load is equal to or more than a predetermined value. You can also

By directly integrating the load amount in this way, it becomes possible to more accurately estimate the activation temperature of the oxygen sensor. In this case,
The management means: -Allows the use of the integrated sensor on the condition that the accumulated load reaches a predetermined load corresponding to the activation temperature of the oxygen sensor. In addition, the prohibiting means according to claim 15 is: -Resetting the integrated load amount of the load amount integrating means on condition that the idle determination time continues for a predetermined time, and the sensor Is prohibited. Will be things.

Further, according to the sixteenth aspect of the present invention, the time integrating means or the load amount integrating means: counts up when the calculated load is equal to or more than a predetermined value, and the load is predetermined. Up / down timer that counts down when it is less than the value. With regard to the management means and the prohibition means, use of the sensor is permitted on condition that the timer value reaches a predetermined value corresponding to the activation temperature of the oxygen sensor, and the timer value is set to the predetermined value. Management means that prohibits the use of the same sensor if it is less than the value. , Respectively.

Even with such a configuration, it becomes possible to manage the presence or absence of activation of the oxygen sensor based on the estimation of the element temperature of the oxygen sensor without using a temperature sensor or the like.

Further, particularly in such a configuration, as in the invention according to claim 17, the up count value Up of the up / down timer is changed to the down count value D.
Setting larger than "own" is effective in increasing the element temperature estimation sensitivity when the sensor is permitted to be used, and further in reducing the control frequency for permitting / prohibiting the use of the sensor. Also in this case, the function as the oxygen sensor arranged on the downstream side of the catalytic converter is sufficiently fulfilled during the active period.

Further, even in each of the configurations of the invention described in claims 13 to 17, as the load of the internal combustion engine having a strong correlation with the element temperature of the oxygen sensor, the amount of intake air to the engine, the basic fuel There are injection quantity and intake air pressure (intake manifold pressure).

Therefore, as each of the load calculating means, as in the invention described in claim 18, an intake air amount calculating means for calculating a value of the intake air amount each time. Alternatively, as in the invention according to claim 19, a fuel basic injection amount calculation means for calculating a value of the fuel basic injection amount each time. Further, according to the invention of claim 20, an intake air pressure calculating means for calculating a value of the intake air pressure each time. By using, it becomes possible to easily and accurately estimate the element temperature of the oxygen sensor through each of these means.

[0073]

【Example】

(First Embodiment) FIG. 1 shows a first embodiment of a management apparatus for an oxygen sensor with a heater according to the present invention.

The apparatus of this embodiment is the above-described double oxygen sensor system having the oxygen sensors with heaters on both the upstream side and the downstream side of the catalytic converter, and in particular, the oxygen sensor with heaters arranged on the downstream side. The device is configured as a device for easily managing the heater energization conditions, the usage conditions, and the like.

It should be noted that the temperature of the exhaust pipe to which these oxygen sensors are mounted has a strong correlation with the load condition of the internal combustion engine, especially the intake air amount, and this exhaust pipe is usually located below the vehicle. Since it is installed, even if the engine is in operation, it has been confirmed by experiments that it is naturally cooled by the outside air at idle and its temperature is flat or drops naturally, etc. That's right.

First, referring to FIG. 1, the structure of the internal combustion engine and its peripheral devices which are the objects of this embodiment will be described. For example, in an internal combustion engine assuming an n-cylinder (n is an arbitrary natural number) 4-cycle engine, its intake air passes from an air cleaner 1 through an air flow meter 2 and an intake pipe 3 as shown in FIG.
It is sucked into each cylinder through the surge tank 4 and the intake manifold 5.

On the other hand, fuel is pressure-fed from a fuel tank (not shown), and is injected and supplied from the fuel injection valve 6 provided in the intake manifold 5 toward each intake valve 15 of the engine.

The gas burned in the cylinder S of the engine is
It is introduced into the catalytic converter 8 through each exhaust valve 16 and the exhaust pipe 7, where the harmful components (CO, H) in the combustion gas are introduced.
C, NOx) are cleaned by a three-way catalyst and discharged.

The air amount (intake air amount) Q of the air sucked into the intake pipe 3 through the air cleaner 1 is detected by the air flow meter 2, and the flow rate thereof is changed by the throttle valve 9 which is linked with the accelerator pedal. Will be controlled. The opening of the throttle valve 9 is detected by the throttle opening sensor 10. Further, in the vicinity of the throttle valve 9, an idle switch 11 that outputs an ON signal when the valve is fully closed is also provided.

The rotation speed Ne of the internal combustion engine is detected by a rotation speed sensor (crank angle sensor) 12 arranged near the crankshaft of the engine. This rotation speed sensor 12
Is provided so as to face a ring gear that rotates in synchronization with the crankshaft of the engine, and outputs a number of pulse signals corresponding to the rotational speed of the engine.

Further, in the exhaust pipe 7, the catalytic converter 8
An oxygen sensor 13 with a heater for detecting the actual unburned oxygen concentration of the exhaust gas in the portion is disposed in the upstream portion of the. As described above, the oxygen sensor 13 arranged on the upstream side of the catalytic converter 8 is used for feedback control of the air-fuel ratio A / F.

Then, in the exhaust pipe 7, a catalytic converter 8
An oxygen sensor with a heater 14 for detecting the unburned oxygen concentration of the exhaust gas cleaned by the catalytic converter 8 is disposed in the downstream portion of the. This catalytic converter 8
The oxygen sensor 14 disposed on the downstream side of the oxygen sensor 14 is a double oxygen sensor system, which is executed when the vehicle equipped with the engine is running steadily, as described above. The variation and deterioration of the output characteristics of the sensor 13 are corrected. (B) Diagnosis of a reduction in the purification rate of the catalytic converter 8 and the like. It is used for such processing. Since the above process (a) is a process used for air-fuel ratio feedback control (to be exact, it assists this), it is hereinafter referred to as a "control" process for convenience, and the above process (b) is also performed. In the following, this is referred to as "diagnosis" processing.

As shown in the sectional structure of FIG. 2, the oxygen sensors 13 and 14 with heaters are provided with a cover 31 provided with a small hole into which exhaust gas flows, and inside the cover 31. The sensor element 32 is made up of a zirconia tube and the like, and a heater 33 disposed inside the sensor element 32 for heating the sensor element 32 is basically provided.

On the other hand, the control device 20 is configured as an arithmetic and logic operation circuit centering on a well-known CPU (central processing unit) 21, ROM (read only memory) 22, RAM (random access memory) 23, backup RAM 24 and the like. ing. Also, CPU2
These respective parts including 1 are connected to each other via an internal bus with an input / output port (I / O port) 25 for inputting signals from the above-mentioned sensors and outputting control signals to each actuator.

Then, in the control device 20, the intake air amount Q and the idle on / off are set via the input / output port 25.
Off information, rotation speed Ne, oxygen concentration (air-fuel ratio A /
F) Sensor signals such as etc. are input, and (1) ON / OFF control of energization to the heater of the oxygen sensor with heater 14 downstream of the catalytic converter 8 is performed based on these sensor signals. (2) The above-mentioned "control" processing is executed including the air-fuel ratio feedback control. (3) The "diagnosis" process is executed. (4) Prior to these "control" processing and "diagnosis" processing, the presence or absence of activation of the oxygen sensor with heater 14 is managed. (5) The fuel injection amount TAU or the like is calculated based on the basic injection amount Tp, and the drive of the fuel injection valve 6 is controlled based on the calculated fuel injection amount TAU. The same processing is executed via the same input / output port 25.

FIG. 3 shows a first example of the control device 20.
FIG. 3 shows a functional configuration of the oxygen sensor with a heater according to the embodiment of the present invention. The configuration of the device of the embodiment and its function will be described in more detail below with reference to FIG. I will describe.

In the control device 20 shown in FIG. 3, the high air amount determination unit 201 first determines whether or not the air amount Q detected by the air flow meter 2 is a predetermined high air amount based on the determination value A. Is a part to be judged.

Although the exhaust pipe 7 is warmed by the heat quantity of the exhaust gas, when the heat quantity of the exhaust gas becomes a small heat quantity at the time of idling as described above, the function of being cooled by the outside air also works. Stop.

Therefore, as the judgment value A, the air amount Q
Based on the above, an air amount that can accurately estimate the temperature of the exhaust pipe 7, that is, an air amount that can determine that the vehicle is in a traveling state rather than an idle state, for example, a value of about 10 g / s is selected. When the intake air amount Q is a value equal to or higher than the determination value A, the exhaust gas heat amount also becomes high,
It is estimated that the temperature of the exhaust pipe 7 is also in the temperature rising state.

Further, the integration timer 202 is active during the period when the high air amount determination unit 201 is determining the intake air amount of the determination value A or more, and the air amount of the determination value A or more is determined. It is a timer that integrates the time that is spent. This integrated time is set as time T1 (i) and the energization-on determination unit 20
Given to 3.

The energization-on determination unit 203 determines that the given integrated time T1 (i), that is, the integrated time during which the exhaust pipe 7 is in the temperature rising state, corresponds to the moisture non-generation temperature of the exhaust pipe 7. This is a part for determining whether or not the time has been reached based on the determination value B.

Incidentally, the temperature at which the water content of the exhaust pipe 7 is not generated, that is, the temperature at which the water droplets and the like described above are not generated in the exhaust pipe 7 and the catalytic converter 8 is approximately 70 ° C. or higher at the temperature of the exhaust pipe 7. In addition, the moisture non-generation temperature 7 of the exhaust pipe 7
It has been confirmed by experiments that the integrated time T1 (i) corresponding to 0 ° C. is about 180 seconds (3 minutes).

Therefore, in the apparatus of the embodiment, the judgment value B
Is set to 180 seconds, and the integrated time T1 (i) is
When it is determined that it has been 80 seconds or more, the energization ON determination unit 203 outputs the energization ON signal ON to the energization control unit 204.

The energization control section 204 receives the energization on signal O
When N is given, the energization flag is set in the energization flag memory 210, and the heater 33 of the oxygen sensor 14 on the downstream side of the catalytic converter (the downstream oxygen sensor heater 14-
33) The energization is started.

On the other hand, in the control device 20, the idle determination section 205 is a section for determining the state where the idle ON signal is output from the idle switch 11, that is, the vehicle is in the idle state.

The idle timer 206 is a timer that is active during the period when the idle state is determined by the idle determination unit 205 and measures the time, that is, the idle time. The idle time is measured as continuous time. That is, idle timer 2
06 is reset each time the idle determination unit 205 determines that the idle state is not established. Then, the measured idle time is given to the energization-off determination unit 207 as time T2 (i).

The energization-off determination unit 207 determines whether or not the given time T2 (i), that is, the idle time, has reached a predetermined time at which water is likely to be generated in the exhaust pipe 7 or the like. This is a part to be determined based on C.

By the way, it has been confirmed by an experiment that the predetermined time when there is a concern that water will be generated in the exhaust pipe 7 is about 30 minutes. Therefore, in the apparatus of the embodiment, the time such as 30 minutes is set as the determination value C, and when it is determined that the idle time T2 (i) is 30 minutes or more, the energization-off determination unit Two
The energization off signal is turned off from the energization control unit 204 from 07
Is output.

The energization control unit 204 receives the energization off signal OFF, and the energization flag memory 210 is supplied.
The energization flag set to is reset, and at the same time, the energization to the downstream oxygen sensor heater 14-33 is released.

When the energization off signal OFF is output from the energization off determination section 207, the integration timer 20
2 is also reset, and the integrated time T1 (i) is initialized to “0”.

On the other hand, in the control device 20, the energization determination unit 211 determines that the energization to the downstream oxygen sensor heater 14-33 is in the on state based on the energization flag being set in the energization flag memory 210. This is the part that determines that

The energization timer 212 is a timer that is active during the period when the energization determination unit 211 determines the energization state of the heater, and measures the time, that is, the energization time. The energization time is also measured as a continuous time, and the energization timer 212 is reset every time the energization determination unit 211 determines that the energization state is not established. The counted energization time is given to the activity determination unit 213 as time T3 (i).

The activity determining section 213 determines, based on the determination value D, whether or not the given energization time T3 (i) has reached a predetermined time corresponding to the activation temperature of the oxygen sensor 14. Is.

Incidentally, the activation temperature of the oxygen sensor 14 is a temperature of 400 ° C. or higher, for example. It has been confirmed by experiments that the activation temperature is reached in about 60 seconds (1 minute) after the energization of the oxygen sensor 14 is started.

Therefore, in the apparatus of the present embodiment, the determination value D is further set to 60 seconds, and the energization time T3 (i) is set.
When it is determined that the time has exceeded 60 seconds, the activation determination unit 213 outputs an activation determination signal to the permission flag management unit 214.

The permission flag management section 214 is a section for managing permission or prohibition of use when the oxygen sensor 14 is used for the above-mentioned "control" processing or "diagnosis" processing.

That is, in the permission flag management unit 214,
On condition that the activation determination signal is output from the activation determination unit 213, the control permission flag is set in the control permission flag memory 220 and the diagnosis permission flag is set in the diagnosis permission flag memory 230. , Manages the use conditions of the oxygen sensor 14.

The control circuit 221 is a well-known circuit for executing the above-mentioned "control" process using the oxygen sensor 14 on condition that the control permission flag is set in the control permission flag memory 220. In addition, the diagnostic circuit 231
Is a well-known circuit that executes the above-mentioned "diagnosis" processing using the oxygen sensor 14 on condition that the diagnosis permission flag is set in the diagnosis permission flag memory 230.

4 to 6 show the processing procedure and processing mode relating to the above-described energization or de-energization of the control device 20, and FIGS. 7 to 8 show the processing relating to the above-mentioned activity determination of the control device 20. The procedure and the processing mode are shown respectively, and the operation of the apparatus according to the first embodiment will be described in more detail below with reference to these figures.

First, the energization process will be described. In the control device 20, the heater 3 of the oxygen sensor 14 arranged on the downstream side of the catalytic converter is processed according to the procedure shown in FIG.
For 3, the energization process S100 is executed. In addition, this energization process S100 is assumed to be executed at a calculation cycle of 262 ms (milliseconds), for example.

In the same energization process S100, based on the comparison between the determination value A (10 g / s) and the intake air amount Q through the high air amount determination unit 201 (step S101), Q ≧
As A, the control device 20 that has determined that the vehicle is in the traveling state is controlled by the integration time T1 (i) of the integration timer 202.
Is incremented as T1 (i) = T1 (i-1) +1 (step S102). T1
(I-1) is the previous accumulated time.

Then, as a result of the increment of the integrated time T1 (i), if the same time T1 (i) is equal to or more than the judgment value B (a value corresponding to a time of 180 seconds, about "700") (step: S103), the energization ON determination unit 20
3, it is determined that the temperature of the exhaust pipe 7 has reached the moisture non-generation temperature. In this case, the energization flag is set in the energization flag memory 210 through the energization control unit 204 (step S104).
The heater 33 of the oxygen sensor 14 is energized (step S105), and the process is temporarily exited.

If the reaching conditions are not satisfied in the air amount determination in step S101 or the integration time determination in step S103, the process is temporarily exited.

Next, the energization canceling process will be described. In the control device 20, in the procedure shown in FIG. 5, a process S20 of releasing the energization of the heater 33 of the oxygen sensor 14 described above.
Execute 0. It should be noted that the energization cancellation process S200 is also executed at a calculation cycle of, for example, 262 ms (milliseconds).

In the energization cancellation process S200, the control device 20 which has determined through the idle determination unit 205 that the idle state is set, the time measured by the idle timer 206, that is, the idle time T2 (i) is T2 (i) = T2. Increment as (i-1) +1 (steps S201 and S2
02). T2 (i-1) is the last idle time.

As a result of the increment of the idle time T2 (i), the same time T2 (i) is equal to the judgment value C.
If it is (a value corresponding to time 30 minutes, about “7000”) or more (step S203), there is a concern that the temperature of the exhaust pipe 7 is lowered to the moisture generation temperature through the energization-off determination unit 207. Judge that there is. Then, in this case, the energization control unit 204 resets the energization flag set in the energization flag memory 210 (step S204) and deenergizes the heater 33 of the oxygen sensor 14 (step S205). After that,
The integration timer 202 is reset (step S20
6) Then, the integrated time T1 (i) is initialized to "0" and the processing is temporarily exited.

When it is determined in the idle determination in step S201 that the idle state is not established, the idle timer 206 is reset (step S207) and the process is temporarily exited.

If the arrival condition is not satisfied in the idle time determination in step S203, the process is temporarily exited. The energization process and the deenergization process are executed by the control device 20 so that the oxygen sensor 14 of the oxygen sensor 14 is turned on / off in the manner shown in FIG. 6, for example. To be done.

That is, it is assumed that, when the vehicle is running, the intake air amount Q changes in the manner shown in FIG. 6 (a), for example. At this time, at time t11, it is determined that the vehicle is in an idle state after the internal combustion engine is started, and the idle timer 206 starts counting time, but at time t12, it is determined that the vehicle has transitioned to the running state. The timing is reset (FIGS. 6D and 6E).

At time t13, the air amount Q exceeds the judgment value A, and the integration timer 202 starts integration of the time T1 (i) (FIG. 6 (b)). After that, each time the air amount Q exceeds the determination value A, the integration of the time T1 (i) by the integration timer 202 is repeated, and at time t14,
This accumulated time T1 (i) exceeds the judgment value B (see FIG. 6).
(B)). As shown in FIG. 6C, the timing at which the integrated time T1 (i) exceeds the determination value B substantially corresponds to the timing at which the temperature of the exhaust pipe 7 reaches 70 ° C., which corresponds to the moisture non-generation temperature. To do.

In this way, the energization-on determination unit 20 has a timing when the integrated time T1 (i) exceeds the determination value B.
An energization ON signal ON is issued from 3. That is, the energization control unit 204 sets the energization flag, and energization of the heater 33 of the oxygen sensor 14 is started (FIG. 6 (f)).

After that, the traveling of the vehicle is stopped,
At time t15, when the idle state is entered again and it is determined by the idle determination unit 205 (FIG. 6 (d)),
The idle timer 206 also starts counting the idle time again (FIG. 6 (e)).

Then, at time t16, the idle time T
When 2 (i) reaches the determination value C, the energization-off determination unit 20
A power-off signal OFF is issued from 7. That is, the energization control unit 204 resets the energization flag and deenergizes the heater 33 of the oxygen sensor 14 (FIG. 6 (f)). At the same time, the integration time T1 (i) in the integration timer 202 is reset (FIG. 6).
(B)).

Next, the activity determination process of the oxygen sensor 14 which is executed as a process after the heater is energized will be described. In the control device 20, according to the procedure shown in FIG.
Processing S30 for determining whether or not the oxygen sensor 14 is active
Execute 0. It should be noted that this activity determination processing S300 is also executed at a calculation cycle of 262 ms (milliseconds), for example.

In the activity determining process S300, the control device 20 which has determined through the energizing determining unit 211 that the energizing flag is set, sets the energizing time of the energizing timer 212, that is, the energizing time T3 (i) to T3 (i). ) = T3 (i-1) +1 (steps S301 and S3)
02). T3 (i-1) is the previous energization time.

As a result of the increment of the energization time T3 (i), if the same time T3 (i) is equal to or more than the judgment value D (a value corresponding to time 60 seconds, about "230") (step). S303), the temperature of the oxygen sensor 14 is 40 as the activation temperature through the activity determination unit 213.
Judge that the temperature has reached 0 ° C. Then, in this case, the permission flag management unit 214 sets the control permission flag in the control permission flag memory 220, sets the diagnosis permission flag in the diagnosis permission flag memory 230 (step S304), and exits the processing once. .

On the other hand, in the energization determination in step S301, when it is determined that the energization flag is not set, the energization timer 212 is reset (step S305) and the control is performed through the permission flag management unit 214. The permission flag and the diagnosis permission flag are reset (step S306), and the processing is temporarily exited.

Further, in the energization time determination in step S303, even when the arrival condition is not satisfied, the control permission flag and the diagnosis permission flag are once reset through the permission flag management unit 214 (step S306).

By executing such activation determination processing through the control device 20, the control permission flag and the diagnosis permission flag are set / reset in the manner shown in FIG.

That is, as shown in FIG. 8B, when the vehicle is running, the oxygen sensor 1 is turned on at time t14.
It is assumed that energization of the heater 33 of No. 4 is started and the element temperature of the heater 33 changes in the mode shown in FIG.

At this time, at the same time t14, the heater 33 is
Is determined by the energization timer 212 and the time T3
Timing of (i) is started. Then, at time t1401
In addition, the element temperature of the oxygen sensor 14 is the activation temperature (400
When the temperature reaches (° C.) (FIG. 8A), the same energization time T3 (i) reaches the determination value D (FIG. 8C). The activity determining unit 213 determines the activity of the oxygen sensor 14 when the energization time T3 (i) reaches the determination value D, and the permission flag managing unit 214 controls the activity at the same time t1401 according to the activity determination. The permission flag and the diagnosis permission flag are set (FIGS. 8D and 8E).

On the other hand, at the subsequent time t16, when the energization of the heater 33 is released due to the increase of the idle time described above, the energization judging section 211 causes the energization timer 212 to operate based on the judgment to that effect. Will be reset. When the activation determination condition (T3 (i) ≧ D) is not satisfied due to the resetting of the energization timer 212, the activation determination unit 213 notifies the permission flag management unit 214 of the fact, and the activation flag management is performed. The control permission flag and the diagnosis permission flag are reset through the unit 214 (FIGS. 8D and 8E).

The control circuit 221 in the control device 20
However, the "control" process using the oxygen sensor 14 is executed on condition that the control permission flag is set, and the diagnostic circuit 231 sets the diagnostic permission flag. Same condition oxygen sensor 1
As described above, the "diagnosis" process using 4 is executed.

As described above, according to the device of the first embodiment, the exhaust pipe 7 can be operated through the integrated value of the time when the intake air amount Q is equal to or more than the predetermined amount without using a temperature sensor or the like. The temperature can be easily estimated.

Since the heater 33 of the oxygen sensor 14 is energized under the condition that the accumulated time reaches a predetermined time corresponding to the moisture non-generation temperature of the exhaust pipe 7, the above-mentioned water drop or the like causes the sensor element The element 32 is heated in a safe state where the element 32 is not touched.

Further, according to the apparatus of the first embodiment, since the heater 33 is de-energized on condition that the idle time is continued for a predetermined time, the exhaust pipe 7 is cooled thereafter. The sensor element 32 is also cooled before the water droplets described above are generated there.

Therefore, also in this case, the safety of the oxygen sensor 14 can be secured without causing the above-mentioned thermal shock and the like. Then, according to such an energization control method for the heater 33, the heater 33
Since there is no concern that the power supply to and from the device will be frequently turned on / off, the function as an oxygen sensor arranged on the downstream side of the catalytic converter 8 can be sufficiently fulfilled during that time.

In addition, when the heater 33 is de-energized, the integrated value of the time when the intake air amount Q is equal to or more than a predetermined amount is reset, so that the exhaust gas when the heater 33 is energized again. The time information required to estimate the tube temperature will also be optimized.

Further, in addition to the device of the first embodiment, after the heater 33 is energized, its energization time is the oxygen sensor 1
The oxygen sensor 14 is allowed to be used under the condition that a predetermined time corresponding to the activation temperature of 4 or more is reached.

Therefore, the above-mentioned "control" is performed by using the oxygen sensor 14 arranged on the downstream side of the catalytic converter 8.
Even when the processing or the "diagnosis" processing is performed, the accuracy related to the control or the diagnosis is appropriately ensured. That is, the oxygen sensor 14 can be used in an optimal state in which the function of the oxygen sensor 14 is sufficiently fulfilled.

In the device of the first embodiment, the control device 20 does not necessarily have to include all the elements described above. Basically, the high air amount determination unit 201, the integration timer 202, the energization ON determination unit 203,
With the configuration including the energization control 204, safe energization to the oxygen sensor 14 is ensured, and the function thereof is stably performed.

In addition to such a basic structure,
The energization determination unit 21 including the energization flag memory 210
1, an energization timer 212, an activation determination unit 213, and a permission flag management unit 214 may be further included,
In that case, the oxygen sensor 14 can be used in a more preferable state.

On the other hand, it is also possible to add only the idle judging section 205, the idle timer 206, and the energization-off judging section 207 to the basic structure. And in this case, at least the oxygen sensor 1
It is possible to easily and surely prevent the cracking of No. 4 and the like, and to secure the safe operation.

In order to perform the idle determination of the internal combustion engine in this way, in an engine that does not include the idle switch 11, the throttle opening sensor 10 operates the predetermined opening of the throttle valve 9 (for example, 3 degrees or less). Idle-on will be determined based on the detection.

(Second Embodiment) FIG. 9 shows a second embodiment of the management apparatus for an oxygen sensor with a heater according to the present invention.

However, the apparatus of the second embodiment also has a large part of the configuration common to the apparatus of the first embodiment, and here, for convenience, the apparatus of the first embodiment and the apparatus of the first embodiment are used. Only the differences will be described.

In the device of the first embodiment, the temperature of the exhaust pipe 7 is estimated through the integrated value of the time when the intake air amount Q is equal to or more than the predetermined amount. However, even though the amount of air is a predetermined amount or more, the amount of air that is close to the determination value A (10 g / s) (for example, 1
1g / s) and air volume at high load (for example, 100g / s)
And, the temperature rising rate of the exhaust pipe 7 is significantly different. Therefore, although the temperature of the exhaust pipe 7 can be estimated more easily according to the device of the first embodiment, there is some concern about the estimation accuracy.

Therefore, in the apparatus of the second embodiment, as shown in FIG. 9, instead of the integrating timer 202,
An air amount integrating unit 202 ′ that integrates the air amount itself of the intake air amount Q that is equal to or more than a predetermined amount is used. Then, in this case, the energization ON determination unit 203 ′ determines whether or not the accumulated air amount SG (i) has reached a predetermined air amount corresponding to the moisture non-generation temperature of the exhaust pipe 7 as a determination value E. Judgment based on

Incidentally, the air amount SG (i) corresponding to the moisture non-generation temperature (about 70 ° C.) of the exhaust pipe 7 is about 1000.
It has been confirmed by an experiment that it is 0 g / s (10 kg / s).

Therefore, in the apparatus of the second embodiment, the judgment value E is set to 10000 g / s, and it is judged that the integrated air amount value SG (i) has become 10000 g / s or more. At this time, the energization ON determination unit 203 ′ outputs an energization ON signal ON to the energization control unit 204.

FIG. 10 and FIG. 11 show an energization processing procedure and an energization processing mode by the apparatus of the second embodiment. In the device of the second embodiment, the controller 20 executes the energization process S100 ′ for the heater 33 of the oxygen sensor 14 in the procedure shown in FIG. It should be noted that this energization process S100 ′ is also executed at a calculation cycle of 262 ms, for example.

That is, in the same energization process S100 ',
Determination value A (10 g / s) through the high air amount determination unit 201
And the intake air amount Q (step S10
1), Q ≧ A, and the control device 20, which has determined that the vehicle is in the traveling state, sets the integrated value SG (i) to SG (i) = SG (i−1) through the air amount integrating unit 202 ′. Addition processing is performed as + G (i) (step S102 '). SG (i
-1) is the previous air amount integrated value, and G (i) is the current air amount that exceeds the determination value A.

Then, as a result of the integration processing of the air amount SG (i), the same air amount integrated value SG (i) is determined by the judgment value E (1
0000 g / s or more (step S10)
3 '), through the energization ON determination unit 203', it is determined that the temperature of the exhaust pipe 7 has reached the moisture non-generation temperature. After that, the energization control unit 20 is the same as the device of the first embodiment.
4 sets the energization flag in the energization flag memory 210 (step S104), and the oxygen sensor 14
The heater 33 is turned on (step S105),
Exit the process once.

Further, in the air amount determination in step S101 or the air amount integrated value determination in step S103 ', if the respective reaching conditions are not satisfied, the process is temporarily exited.

By performing such energization processing through the apparatus of the second embodiment, in the oxygen sensor 14, for example, in the mode shown in FIG. 11, that is, the air amount integrated value SG (i). Time t when the judgment value E reaches
At 24, the energization of the heater 33 is turned on (FIG. 11).
(A)-(c)).

As described above, according to the apparatus of the second embodiment, it is possible to more accurately estimate the moisture non-generation temperature of the exhaust pipe 7 based on the integrated value of the intake air amount Q itself. become.

The conditions under which the heater 33 is turned off, the conditions under which the oxygen sensor 14 is determined to be active, and the like are the same as those of the device of the first embodiment. The precautions and modifications described for the device of the first embodiment are also applied as they are to the device of the second embodiment.

(Third Embodiment) FIG. 12 shows a third embodiment of the management apparatus for an oxygen sensor with a heater according to the present invention.

The device of the third embodiment also has a basic configuration common to the device of the first embodiment, and here again, for convenience, only the differences from the device of the first embodiment will be described. Will be described.

In the apparatus of the third embodiment, as shown in FIG. 12, the integration timer 202, the energization ON judging section 203, and the idle judging section 20 in the apparatus of the first embodiment.
5, idle timer 206, and energization off determination unit 207
Instead of up / down timer 208 and energization on / off
The off determination unit 209 is used.

Here, the up / down timer 208 is
The timer counts up when the intake air amount Q is equal to or more than a predetermined amount and counts down when the intake air amount Q is less than a predetermined value. In the device of the third embodiment, for example, the value "3" is set as the up-count value Up and the value "1" is set as the down-count value Down to make the clocking speeds different.

Further, the energization ON / OFF judging section 209 uses the up / down timer 208 to measure the time T4.
In a portion for judging whether or not (i) has reached a predetermined time corresponding to the moisture non-generation temperature of the exhaust pipe 7, based on the judgment value B (value corresponding to time 180 seconds, about “700”). is there. Then, the energization ON / OFF determination unit 209 outputs an energization ON signal ON to the energization control unit 204 on condition that the time count T4 (i) is equal to or greater than the determination value B, and the same time T4 (i). When is less than the determination value B, the energization off signal OFF is output to the same energization control unit 204.

FIG. 13 and FIG. 14 show the energization / de-energization processing procedure by the apparatus of the third embodiment and its processing mode. In the device of the third embodiment, the control device 20
Thus, the energization / de-energization process S400 is executed for the heater 33 of the oxygen sensor 14 in the procedure shown in FIG. Note that this process S400 is also 262 m, for example.
It shall be executed in the calculation cycle of s.

That is, in the same energization / de-energization processing S400, the controller 20 compares the judgment value A (10 g / s) and the intake air quantity Q through the high air quantity judgment unit 201 (step S401) with Q. When it is determined that ≧ A and the vehicle is in a traveling state, the time count T4 (i) is added through the up / down timer 208 as T4 (i) = T4 (i-1) +3 ( (Step S402), otherwise, the up / down timer 208 subtracts the measured time T4 (i) as T4 (i) = T4 (i-1) -1 (step S403). T4 (i-
All of 1) are the previous clock time.

If the time T4 (i) is greater than or equal to the judgment value B (a value corresponding to time 180 seconds, about "700") as a result of the timekeeping process in this manner (step S404), Through the energization on / off determination unit 209, it is determined that the temperature of the exhaust pipe 7 has reached the moisture non-generation temperature. After that, the energization flag memory 2 is passed through the energization control unit 204 as in the previous embodiments.
The energization flag is set to 10 (step S4
05), energize the heater 33 (step S
406), the process is temporarily exited.

On the other hand, as a result of the above timing processing, time T4
If (i) is less than the judgment value B (step S40)
4) Through the same energization ON / OFF determination unit 209, it is determined that the temperature of the exhaust pipe 7 has not reached the moisture non-generation temperature, or has decreased to a temperature at which moisture generation may occur.
In this case, the energization flag is reset through the energization control unit 204 (step S407), and the energization of the heater 33 is released (step S408).
Exit the process once.

By performing such energization / deenergization processing through the device of the third embodiment, in the oxygen sensor 14, for example, in the mode shown in FIG. 14, the above-mentioned clock time T4 (i) is measured. Each time the crosses the judgment value B, the energization of the heater 33 is controlled to be turned on / off (FIGS. 14A to 14C).

As described above, also in the device of the third embodiment, the oxygen sensor 14 arranged downstream of the catalytic converter is estimated based on the estimation of the exhaust pipe temperature without using a temperature sensor or the like. Can be safely heated and cooled.

Further, particularly in such a configuration, by setting the up count value Up of the up / down timer 208 to be larger than the down count value Down, the exhaust pipe temperature estimation sensitivity when the heater is energized is further improved, and The ON / OFF frequency of the heater energization can be reduced well.
Basically, even if the count values are set to the same value such as "1", the above-described functions and operations of the apparatus of the embodiment can be realized. As a result, even in the configuration of the device of the third embodiment, the function as the oxygen sensor 14 is sufficiently fulfilled during the active period.

Incidentally, also in the apparatus of the third embodiment,
The conditions and the like for determining the activity of the oxygen sensor 14 are the same as those of the device of the first or second embodiment. Further, also in the device of the third embodiment, the control device 20 basically has a high air amount determination unit 201 and an up / down timer 20.
8, energization on / off determination unit 209, and energization control 204
It is not necessary to include all the elements omitted from the illustration in FIG.

(Fourth Embodiment) FIG. 15 shows a fourth embodiment of the management apparatus for an oxygen sensor with a heater according to the present invention.

In the device of the fourth embodiment, the method of judging the activity of the oxygen sensor 14 in the device of the first embodiment is partially changed, and after the energization of the heater 33 of the sensor 14 is started,
It is configured as a device that directly estimates the element temperature and determines whether or not the sensor 14 is active.

However, most of the configuration of the device of the fourth embodiment is also common to the device of the first embodiment described above, and here again, for convenience, it is the same as the device of the first embodiment. Only the differences will be described.

That is, in the device of the fourth embodiment, as shown in FIG. 15 as the configuration of the control device 20 thereof, an activity determining section which replaces the above-described energizing determining section 211, energizing timer 212 and activity determining section 213. It is configured with 240.

The activity determining section 240 estimates the element temperature of the oxygen sensor 14 by diverting the integration time T1 (i) by the integration timer 202 on condition that the energization flag is set in the energization flag memory 210. , A part for judging the presence or absence of the activity based on the judgment value F.

FIG. 16 shows the activity determination processing procedure executed by the activity determining section 240 by the apparatus of the fourth embodiment. In the activity determination process S500 shown in FIG. 16, the activity determination unit 240 first determines the energization flag memory 21.
It is confirmed that the energization flag is set to 0 (step S501). This activity determination process S500 is also executed at a calculation cycle of 262 ms, for example.

After that, referring to the integration time T1 (i) by the integration timer 202, if the integration time T1 (i) is not less than the judgment value F (step S502), the element temperature of the oxygen sensor 14 becomes active. It is determined that the temperature (approximately 400 ° C.) has been reached. The determination value F is preset to a value corresponding to a time of 180 seconds (3 minutes) or more, for example.

When the activity of the oxygen sensor 14 is determined in this way, the control permission flag and the diagnosis permission flag are set through the permission flag management unit 214 (step S503), and the process is temporarily exited.

On the other hand, when the energization flag is not set, or when the reaching condition for the determination value F is not satisfied in the determination of the integration time T1 (i), the control permission flag is passed through the permission flag management unit 214. And the diagnosis permission flag is in the reset state (step S50
4) The process is temporarily exited.

The activation determination process is executed by the apparatus of the fourth embodiment, whereby the control permission flag and the diagnosis permission flag are respectively set in the modes shown in FIG.
The set / reset mode becomes controlled.

Incidentally, in FIG. 17, the time TM indicates the margin. That is, in the example here, the oxygen sensor 14
From the time t1402 when the element temperature is estimated to reach the activation temperature (approximately 400 ° C.), the margin time TM is further taken into consideration, and the activation determination based on the determination value F is performed. By adding such a time TM as the margin, the oxygen sensor 14 is surely activated when the control permission flag and the diagnosis permission flag are set in the modes shown in FIGS. 17 (d) and 17 (e). It seems that the temperature has been reached. Therefore, the “control” process or the “diagnosis” process using the oxygen sensor 14 can also be executed with higher reliability.

As described above, according to the device of the fourth embodiment, when the above-mentioned "control" process or "diagnosis" process is performed by using the oxygen sensor 14 arranged on the downstream side of the catalytic converter 8. However, the accuracy of the control and diagnosis can be properly secured.

Moreover, in the device of the fourth embodiment, since the element temperature of the oxygen sensor 14 is directly estimated and the presence or absence of the activity is determined, the determination accuracy becomes more accurate, and The configuration for that is also the energization timer 2
Since 12 or the like is not used, it is simpler than the device of the first embodiment.

(Fifth Embodiment) FIG. 18 shows the fifth embodiment of the management apparatus for an oxygen sensor with a heater according to the present invention.

The apparatus of the fifth embodiment is constructed as an apparatus in which the activity judging method by the apparatus of the fourth embodiment described above is applied to the apparatus of the second embodiment. That is, in the device of the fifth embodiment, as shown in FIG. 18, on the condition that the energization flag is set in the energization flag memory 210, the air amount integration value SG (i) by the air amount integration unit 202 '. Is used to estimate the element temperature of the oxygen sensor 14 and to determine the presence or absence of the activity based on the determination value G.

FIG. 19 shows the procedure of the activity determining process performed by the apparatus of the fifth embodiment executed through the activity determining unit 240 '. The activity determination process S500 ′ shown in FIG.
In step S <b> 501, the activity determination unit 240 ′ first confirms that the energization flag is set in the energization flag memory 210 (step S 501), and then refers to the air amount integration value SG (i) by the air amount integration unit 202 ′. . If the integrated air amount value SG (i) is equal to or greater than the determination value G (step S502 '), it is determined that the element temperature of the oxygen sensor 14 has reached its activation temperature (approximately 400 ° C). The determination value G is, for example, 10000 g / s (10
kg / s), or a value corresponding to an air amount of more than that is preset.

Thereafter, similar to the device of the fourth embodiment,
In this way, when the activity of the oxygen sensor 14 is determined,
A control permission flag and a diagnosis permission flag are set through the permission flag management unit 214 (step S503),
Exit the process once.

On the other hand, when the energization flag is not set, or when the reaching condition for the judgment value G is not satisfied in the judgment of the integrated air amount value SG (i), control is performed through the permission flag management unit 214. When the permission flag and the diagnosis permission flag are in the reset state (step S504), the process is temporarily exited.

The activation determination process is executed by the apparatus of the fifth embodiment, whereby the control permission flag and the diagnosis permission flag are respectively set in the modes shown in FIG.
The set / reset mode becomes controlled.

Incidentally, also in FIG. 20, the time TM after the time t1402 'corresponding to the activation temperature reaching point shows a margin. Therefore, also in the example here, FIG.
When the control permission flag and the diagnosis permission flag are set in the mode shown in (e), the oxygen sensor 14 surely reaches the activation temperature, and the "control" using the oxygen sensor 14 is performed. The “processing” or the “diagnosis” processing can be executed with higher reliability.

As described above, also when the apparatus of the fifth embodiment is used to perform the above-mentioned "control" processing and "diagnosis" processing by using the oxygen sensor 14 arranged on the downstream side of the catalytic converter 8, The accuracy concerning the control and diagnosis can be appropriately secured.

In the device of the fifth embodiment, in order to estimate the element temperature of the oxygen sensor 14, the integrated value of the air amount itself is referred to as in the device of the second embodiment. As a result, the activity determination accuracy can be improved more than that of the device of the fourth embodiment.

(Sixth Embodiment) FIG. 21 shows a sixth embodiment of an oxygen sensor management device with a heater according to the present invention.

The apparatus of the sixth embodiment is configured as an apparatus in which the activity judging method by the apparatus of the above-mentioned fourth or fifth embodiment is applied to the apparatus of the above-mentioned third embodiment. There is.

That is, the device of the sixth embodiment is shown in FIG.
1, the element temperature of the oxygen sensor 14 is estimated by referring to the time T4 (i) measured by the up / down timer 208 on condition that the energization flag is set in the energization flag memory 210. An activity determination unit 241 that determines the presence or absence of the activity based on the determination value F is configured.

FIG. 22 shows an activity determination processing procedure executed by the activity determining section 241 by the apparatus according to the sixth embodiment. In the activity determination process S600 shown in FIG. 22, the activity determining unit 241 first determines the energization flag memory 21.
After confirming that the energization flag is set to 0 (step S601), the time T4 (i) measured by the up / down timer 208 is referred to. And the time T
4 (i) is greater than or equal to the judgment value F (step S60
2) It is determined that the element temperature of the oxygen sensor 14 has reached its activation temperature (approximately 400 ° C.). Judgment value F
Is preset to 180 seconds (3 minutes) or a time equivalent value of 180 seconds (3 minutes) or more, as described above.

Thereafter, as in the case of the apparatus of the fourth or fifth embodiment, when the activity of the oxygen sensor 14 is judged in this way, the control permission flag and the diagnosis permission flag are set through the permission flag management unit 214. Then (step S
603), the processing is temporarily exited.

On the other hand, when the energization flag is not set, or when the reaching condition for the judgment value F is not satisfied in the judgment of the above-mentioned time count T4 (i), control permission is given through the permission flag management unit 214. When the flag and the diagnosis permission flag are in the reset state (step S604), the process is temporarily exited.

The activation determination process is executed by the apparatus of the sixth embodiment, so that the control permission flag and the diagnosis permission flag are respectively in the modes shown in FIG.
The set / reset mode becomes controlled.

Also in FIG. 23, the time TM after the time t1402 corresponding to the activation temperature reaching point shows the margin. Therefore, in this example as well, when the control permission flag and the diagnosis permission flag are set in the manners shown in FIGS. 23D and 23E, the oxygen sensor 14 also surely reaches the activation temperature. Therefore, the “control” process or the “diagnosis” process using the oxygen sensor 14 can be executed with higher reliability.

As described above, also when the apparatus of the sixth embodiment is used to perform the above-mentioned "control" processing and "diagnosis" processing by using the oxygen sensor 14 arranged on the downstream side of the catalytic converter 8, The accuracy concerning the control and diagnosis is preferably ensured.

Also, in the apparatus of the sixth embodiment, the up count value Up of the up / down timer 208 is set to be larger than the down count value Down, as in the apparatus of the third embodiment. As a result, the sensitivity for determining the activity of the oxygen sensor 14 is improved, and further, the control frequency for permitting / prohibiting the use of the sensor 14 can be favorably reduced. Basically, even if the count values are set to the same value such as "1", the above-described functions and operations of the apparatus of the embodiment can be realized. With the setting, the “control” process or the “diagnosis” process using the oxygen sensor 14 can be executed more stably.

(Seventh Embodiment) An oxygen sensor with a heater such as the oxygen sensor 14 can be selectively used for the heater at all times (mainly when used as an oxygen sensor upstream of the catalytic converter) or at a low temperature. In addition to the oxygen sensor with a standard heater that is energized, there is an oxygen sensor with a low power heater.

This oxygen sensor with a low power heater has an element temperature of, for example, less than 400.degree. C. in an environment where the above-mentioned water droplets and the like are likely to occur, for example, while being idle, as shown in FIG. In the environment mirror that is maintained at a low temperature of 100 degrees Celsius and does not generate the water droplets when the vehicle is in a steady running state, the heater power is adjusted so that the element power is maintained at a high temperature of, for example, 400 degrees Celsius or higher. It is a sensor. That is, this low-power heater-equipped oxygen sensor is an oxygen sensor of the type that is constantly energized, and does not require on / off control of energization of the heater. If such an oxygen sensor with a low power heater is used, the above-mentioned element breakage and the like can be naturally prevented.

On the other hand, even with such an oxygen sensor with a low-power heater, the element temperature thereof is, for example, 400 ° C. when the idle state is changed to the steady running state.
A response delay as shown in FIG. 24 also occurs from a low temperature of less than 1 to an activation temperature (high temperature of 400 ° C. or higher).

Even in the oxygen sensor with the low power heater, the element temperature thereof has a strong correlation with the load of the internal combustion engine, especially with the intake air amount Q. Further, since the oxygen sensor is also attached to the exhaust pipe 7 and is disposed on the lower side of the vehicle, even when the engine is in an operating state, it is naturally cooled by the outside air during idling, The temperature is either flat or falls naturally.

Therefore, FIG. 25 shows, as a seventh embodiment of the heater oxygen sensor management device according to the present invention, a device employing such a low power heater oxygen sensor, and a low power heater oxygen sensor. This section describes a device that can be used for effective state management.

That is, in the device of the seventh embodiment, the oxygen sensor 1 arranged downstream of the catalytic converter 8 is used.
4 assumes such a low-power heater oxygen sensor. Also in the device of the seventh embodiment, the element temperature of the oxygen sensor 14 is directly estimated to determine whether the oxygen sensor 14 is active.

The entire structure including the internal combustion engine of the seventh embodiment is the same as that shown in FIG.
It shall conform to the configuration shown in. Also in FIG. 25, the same elements as those used in the apparatuses of the above-described embodiments are denoted by the same reference numerals.

Now, in the device of the seventh embodiment shown in FIG. 25, the high air amount judging section 201 determines whether or not the air amount Q detected by the air flow meter 2 is at a predetermined high air amount. Is a portion for determining based on the determination value H. Even with this determination value H, the amount of air that can accurately estimate the element temperature of the oxygen sensor 14 based on the amount of air Q, that is, the amount of air that can determine that the vehicle is in the running state rather than the idle state, for example, 10 g / A value of about s is selected. When the intake air amount Q is a value equal to or higher than the determination value A, the exhaust gas heat amount also becomes high, and the oxygen sensor 14
It is estimated that the element temperature of is also in a temperature rising state.

Further, the integration timer 202 is active during the period when the high air amount determination unit 201 determines the intake air amount of the determination value H or more, and the air amount of the determination value H or more is determined. It is a timer that integrates the time that is spent. This integrated time is given to the activity determination unit 251 as time T5 (i).

The activity determining section 251 reaches the predetermined time corresponding to the activation temperature of the oxygen sensor 14 by the given integration time T5 (i), that is, the integration time in which the element temperature is in the temperature rising state. This is a part for determining whether or not based on the determination value I.

Incidentally, the activation temperature of the oxygen sensor 14 is about 400 ° C. as described above, and the integration time T5 (i) corresponding to the activation temperature 400 ° C. is about 1.
It has been confirmed by experiment that the time is 80 seconds (3 minutes).

Therefore, in the device of the seventh embodiment, when the judgment value I is set to 180 seconds and it is judged that the integrated time T5 (i) is 180 seconds or more, the activation judgment is made. The activation determination signal is output from the unit 251 to the permission flag management unit 214.

The permission flag management unit 214 receives the activation determination signal, and thereby the control permission flag memory 220
Set the control permission flag to the diagnostic permission flag memory 2
The diagnostic permission flag is set to 30.

Incidentally, the control circuit 221 in the control device 20.
Is to execute the "control" process using the oxygen sensor 14 on condition that the control permission flag is set, and the diagnosis circuit 231 has the diagnosis permission flag set. As described above, the "diagnosis" process using the oxygen sensor 14 is executed under the condition of.

On the other hand, the idle determination section 205 is a section for determining that the idle ON signal is being output from the idle switch 11, that is, that the vehicle is in the idle state.

The idle timer 206 is a timer that is active during the period when the idle state is determined by the idle determination unit 205 and measures the time, that is, the idle time. As described above, the idle time is measured as continuous time. The measured idle time is the time T6 (i), and the inactivity determination unit 25
Given to 2.

The inactivity determining section 252 determines whether or not the given time T6 (i), that is, the idle time, has reached a predetermined time at which there is a concern that the oxygen sensor 14 may shift to the inactive state. This is a part to be judged based on the judgment value J.

By the way, it has been confirmed by experiments that the predetermined time in which there is a concern that the oxygen sensor 14 may shift to the inactive state is about 30 minutes. Therefore, in the device of the seventh embodiment, the time such as 30 minutes is set as the determination value J, and the idle time T6 is set.
When it is determined that (i) has reached 30 minutes or more, the inactivity determination unit 252 determines that the permission flag management unit 214
In response to this, an inactivity determination signal is output.

The permission flag management section 214 receives the inactivity judgment signal to reset the control permission flag set in the control permission flag memory 220 and set it in the diagnosis permission flag memory 230. Reset the diagnostic enable flag.

When the inactivity determination signal is output from the inactivity determination section 252, the integration timer 202 is operated.
Is also reset and the integrated time T5 (i) is initialized to "0".

26 to 28 show a processing procedure and a processing mode relating to the above-mentioned activation judgment or inactivation judgment by the apparatus of the seventh embodiment, and hereinafter, with reference to each of these drawings. The operation of the apparatus according to the seventh embodiment will be described in more detail.

First, the activity determination process will be described. In the device of the seventh embodiment, the activity determining process S700 of the oxygen sensor 14 is executed in the procedure shown in FIG.
Note that this activity determination processing S700 also takes, for example, 262 ms.
It shall be executed in the calculation cycle of (millisecond).

In the same process S700, based on the comparison between the determination value H (10 g / s) and the intake air amount Q through the high air amount determination unit 201 (step S701), it is determined that Q ≧ H and the vehicle is in the running state. Control device 2 determined to be in
0 increments the integration time T5 (i) of the integration timer 202 as T5 (i) = T5 (i-1) +1 (step S702). T5
(I-1) is the previous accumulated time.

As a result of the increment of the integrated time T5 (i), if the same time T5 (i) is equal to or more than the judgment value I (a value corresponding to time 180 seconds, about "700") (step) In step S703, the activity determination unit 251 determines that the element temperature of the oxygen sensor 14 has reached the activity temperature. Then, in this case, the control permission flag and the diagnosis permission flag are further set through the permission flag management unit 214 (step S704), and the process is temporarily exited.

If the arrival conditions are not satisfied in the air amount determination in step S701 or the integration time determination in step S703, the process is temporarily exited.

Next, the inactivity judgment processing will be described.
In the device of the seventh embodiment, the process S80 for determining the inactivity of the oxygen sensor 14 is performed in the procedure shown in FIG.
Execute 0. This inactivity determination processing S800 is also executed at a calculation cycle of 262 ms, for example.

In the inertness determination processing S800, the control device 20 which has determined through the idle determination section 205 that the idle state is set, the control device 20 sets the time measured by the idle timer 206, that is, the idle time T6 (i) to T6 (i) = Increment as T6 (i-1) +1 (steps S801 and S8)
02). T6 (i-1) is the last idle time.

Then, as a result of the increment of the idle time T6 (i), the same time T6 (i) becomes equal to the judgment value J.
If it is equal to or greater than (a value corresponding to time 30 minutes, about "7000") (step S803), the inactivity determination unit 2 is activated.
Through 52, it is determined that there is a concern that the element temperature of the oxygen sensor 14 is lowered to the inactive temperature. Then, in this case, the control flag and the diagnosis permission flag are reset through the permission flag management unit 214 (step S804). After that, the integration timer 202 is reset (step S805), and the integration time T5
(I) is initialized to "0" and the processing is temporarily exited.

If it is determined in the idle determination in step S801 that the idle state is not set, the idle timer 206 is reset (step S806) and the process is temporarily exited.

If the reaching condition is not satisfied in the idle time determination in step S803, the process is temporarily exited. By executing the activation determination process and the inactivity determination process through the device of the seventh embodiment, the control permission flag and the diagnosis permission flag are set or reset in the mode shown in FIG. 28, for example. Controlled.

That is, it is assumed that, when the vehicle is running, the intake air amount Q changes in the manner shown in FIG. 28 (a), for example. At this time, at time t31, it is determined that the vehicle is in the idle state after starting the internal combustion engine, and the idle timer 206 starts counting time, but at time t32, it is determined that the vehicle has transitioned to the running state. The timing is reset (FIGS. 28D and 28E).

Then, at time t33, the air amount Q exceeds the judgment value H, and the integration timer 202 starts integrating the time T5 (i) (FIG. 28 (b)). After that, each time the air amount Q exceeds the judgment value H, the accumulation of the time T5 (i) by the integration timer 202 is repeated, and at time t35, this integration time T5 (i) exceeds the judgment value I (FIG. 28). (B)). And thus, the total time T5
At the timing (i) exceeds the judgment value I, the control permission flag and the diagnosis permission flag respectively have the control permission flag memory 220 and the diagnosis permission flag memory 230.
(FIGS. 28 (f) and 28 (g)).

In this example, as shown in FIG. 28C, the element temperature of the oxygen sensor 14 reaches the activation temperature at the timing when the integrated time T5 (i) exceeds the judgment value I. Is set to a time with a margin of time TM with respect to the time t34 estimated. By providing such a margin time TM, the oxygen sensor 14 surely reaches the activation temperature when the flags are set, and the "control" process using the oxygen sensor 14 or " As described above, the "diagnosis" process can be executed with higher reliability.

Then, when the running of the vehicle is stopped and the vehicle enters the idle state again at time t36 and it is judged by the idle judging section 205 (FIG. 28 (d)), the idle timer 206 also sets the idle time again. The time counting of is started (FIG. 28 (e)).

At time t37, the idle time T
When 6 (i) reaches the judgment value J, both the control permission flag and the diagnosis permission flag are reset (FIGS. 28 (f) and (g)). At the same time, the integration time T5 (i) in the integration timer 202 is reset (FIG. 28 (b)).

As described above, according to the device of the seventh embodiment, even when the oxygen sensor with the low power heater described above is used as the oxygen sensor 14 arranged on the downstream side of the catalytic converter 8, Based on the estimation of the element temperature, the presence or absence of the activity can be determined easily and accurately.
Then, the oxygen sensor with the low power heater can be used in an optimal state in which the oxygen sensor is sufficiently fulfilled.

Further, when it is estimated that the oxygen sensor 14 shifts to the inactive state, the integrated value during the time when the intake air amount Q is equal to or more than the predetermined amount is reset, so that the same again. The time information required for estimating the element temperature when determining the activity is also optimized.

Also in this case, as in the case of the device of the first embodiment, in the engine without the idle switch 11 for executing the idle determination of the internal combustion engine, the throttle valve by the throttle opening sensor 10 is used. The idle-on is determined based on the detection of the predetermined opening degree of 9 (for example, 3 degrees or less).

However, in the system in which only the activation period of the oxygen sensor 14 is a management target when executing the "control" process and the "diagnosis" process, the idle determination unit 205 and the idle timer 206 are included. The provision of the inactivity determining unit 252 and the like is not always necessary.

(Eighth Embodiment) FIG. 29 shows an eighth embodiment of the oxygen sensor equipped controller with a heater according to the present invention.

However, the apparatus of the eighth embodiment has a large part of the configuration common to the apparatus of the seventh embodiment, and here, for convenience, the apparatus of the seventh embodiment will be described. Only the differences will be described.

In the device of the seventh embodiment, the oxygen sensor 14 passes through the integrated value of the time when the intake air amount Q is equal to or more than the predetermined amount.
The device temperature was estimated. However, although the temperature estimation based on such an integrated value of time is a simpler method as described above, there is some concern about the estimation accuracy.

Therefore, in the apparatus according to the eighth embodiment, as shown in FIG.
As shown in 9, instead of the integration timer 202,
An air amount integrating unit 202 ′ that integrates the air amount itself of the intake air amount Q that is equal to or more than a predetermined amount is used. In this case, the activity determination unit 251 ′ determines based on the determination value K whether or not the accumulated air amount SG (i) has reached a predetermined air amount corresponding to the activation temperature of the oxygen sensor 14. To do.

Incidentally, the air amount SG (i) corresponding to the activation temperature (approximately 400 ° C.) of the oxygen sensor 14 is approximately 100.
It has been confirmed by experiments that the amount is 00 g / s (10 kg / s).

Therefore, in the device of the eighth embodiment, the judgment value K is set to 10000 g / s, and it is judged that the integrated air amount value SG (i) becomes 10000 g / s or more. At this time, the activation determining unit 251 ′ outputs the activation determining signal to the permission flag managing unit 214.

FIGS. 30 and 31 show the activity determination processing procedure and the activity determination processing mode by the apparatus of the eighth embodiment. In the device of the eighth embodiment, the controller 20 controls the oxygen sensor 14 according to the procedure shown in FIG.
The activity determination process S700 ′ is performed. The activity determination process S700 ′ is also executed at a calculation cycle of 262 ms, for example.

That is, in the same judgment processing S700 ',
Judgment value H (10 g / s) through the high air amount judgment unit 201
And the intake air amount Q (step S70
1), Q ≧ H, and the control device 20, which has determined that the vehicle is in a traveling state, sets the integrated value SG (i) to SG (i) = SG (i−1) through the air amount integration unit 202 ′. Addition processing is performed as + G (i) (step S702 ′). Again, SG (i-1) is the previous integrated value of the air amount, G
(I) is the current air amount that exceeds the determination value A.

Then, as a result of the integration processing of the air amount SG (i), the same air amount integrated value SG (i) is determined by the judgment value K (1
0000 g / s or more (step S70)
3 '), the oxygen sensor 14 through the activity determination unit 251'.
It is determined that the element temperature of has reached the activation temperature. After that, the permission flag management unit 214 is the same as the device of the seventh embodiment.
The control permission flag and the diagnosis permission flag are respectively set through (step S704), and the process is temporarily exited.

Further, in the air amount determination in step S701 or the air amount integrated value determination in step S703 ', if the respective reaching conditions are not satisfied, the process is temporarily exited.

By executing such activity determination processing through the apparatus of the eighth embodiment, the control permission flag and the diagnosis permission flag are set in the manner shown in FIG. 31, that is, the air amount integrated value SG (i). ) Reaches the judgment value K at time t45, both are set (FIG. 31).
(A)-(d)). Then, the above-described "control" process and "diagnosis" process using the oxygen sensor 14 are enabled.

It should be noted that the judgment value K can be set to a slightly larger value in consideration of the margin TM described above to further improve the reliability of these "control" processing and "diagnosis" processing. Of course.

As described above, according to the device of the eighth embodiment, the element temperature of the oxygen sensor 14 can be estimated more accurately based on the integrated value of the intake air amount Q itself. .

In the apparatus of the eighth embodiment, the conditions for determining the oxygen sensor 14 to be inactive are the same as those in the seventh embodiment.
The device is the same as that of the embodiment. Moreover, the notes and modifications described for the apparatus of the seventh embodiment are also applied as they are to the apparatus of the eighth embodiment.

(Ninth Embodiment) FIG. 32 shows a ninth embodiment of the management apparatus for an oxygen sensor with a heater according to the present invention.

The device of the ninth embodiment also has a basic configuration common to the device of the seventh embodiment, and here again, for convenience, only the differences from the device of the seventh embodiment will be described. Will be described.

In the device of the ninth embodiment, as shown in FIG. 32, the integration timer 202, the activation determination unit 251, the idle determination unit 205, the idle timer 206, and the inactivity timer in the device of the seventh embodiment are used. Instead of the determination unit 252, the up / down timer 208 and the active / inactive determination unit 253 are used.

As described above, the up / down timer 208 is a timer that counts up when the intake air amount Q is equal to or greater than a predetermined amount and counts down when the air amount Q is less than the predetermined value. is there. In addition, the same 9th
Also in the apparatus of the above embodiment, the up-count value Up is set to, for example, the value "3", and the down-count value Down is set to, for example, the value "1" to make the clocking speeds different.

Further, the active / inactive judging section 253 uses the up / down timer 208 to measure time T7 (i).
Is a portion that determines whether or not a predetermined time corresponding to the activation temperature of the oxygen sensor 14 has been reached based on the above-described determination value I (a value corresponding to time 180 seconds, about “700”). Then, in the same activity / inactivity determining section 253, the time count T
7 (i) is greater than or equal to the determination value I, the activation determination signal is output to the permission flag management unit 214, and the same time T
When 7 (i) is less than the determination value I, the inactivity determination signal is output to the permission flag management unit 214.

FIG. 33 and FIG. 34 show the active / inactive judgment processing procedure and the processing mode thereof by the apparatus of the ninth embodiment. In the device of the ninth embodiment, its control device 2
0, the oxygen sensor 14 is operated in the procedure shown in FIG.
The processing S900 for determining the activation / inactivation of is executed. This processing S900 is also executed at a calculation cycle of 262 ms, for example.

That is, the same activity / inactivity determination processing S900
In step S901, the control device 20 determines that Q ≧ H based on the comparison between the determination value H (10 g / s) and the intake air amount Q through the high air amount determination unit 201, and the vehicle is in the traveling state. If it is determined that the time count T7 (i) is added as T7 (i) = T7 (i-1) +3 through the up / down timer 208 (step S902), otherwise, The counting time T7 (i) is subtracted by the up / down timer 208 as T7 (i) = T7 (i-1) -1 (step S903). T7 (i-
All of 1) are the previous clock time.

If the time T7 (i) is greater than or equal to the judgment value I (a value corresponding to 180 seconds, about "700") as a result of the timekeeping processing in this manner (step S904), Through the activation / deactivation determination unit 253, it is determined that the element temperature of the oxygen sensor 14 has reached the activation temperature. Then, after that, as in the seventh or eighth embodiment, the control permission flag and the diagnosis permission flag are set through the permission flag management unit 214 (step S905), and the process is temporarily exited.

On the other hand, as a result of the above timing processing, time T7
If (i) is less than the judgment value I (step S90)
4) Through the same activity / inactivity determining section 253, it is determined that there is a concern that the element temperature of the oxygen sensor 14 has dropped to the inactive temperature. In this case, both the control permission flag and the diagnosis permission flag are reset through the permission flag management unit 214 (step S906), and the process is temporarily exited.

By executing the activation / deactivation determination processing through the apparatus of the ninth embodiment, the control permission flag and the diagnosis permission flag are set to the time count T7 in the mode shown in FIG. 34, for example. (I) is the judgment value I
Each time the crossing is performed, the state is controlled to be set or reset (FIGS. 34A to 34D).

Also in this case, if the judgment value I is set to a slightly larger value in consideration of the margin TM, the reliability of the "control" processing and the "diagnosis" processing can be further improved. Will be able to.

As described above, also in the device of the ninth embodiment, even when the oxygen sensor with the low power heater described above is used as the oxygen sensor 14 arranged on the downstream side of the catalytic converter 8, its element The presence or absence of the activity can be easily and accurately determined based on the temperature estimation.

Also in the apparatus of the ninth embodiment, the up count value Up of the up / down timer 208 is set to be larger than the down count value Down, as in the case of the apparatus of the sixth embodiment. As a result, the sensitivity for determining the activity of the oxygen sensor 14 is improved, and further, the control frequency for permitting / prohibiting the use of the sensor 14 is favorably reduced. Basically, even if the count values are set to the same value such as "1", the above-described functions and operations of the apparatus of the embodiment can be realized. By setting the oxygen sensor 1
The "control" processing or the "diagnosis" processing using 4 can be executed more stably.

By the way, in any of the above first to ninth embodiments, as a load of the internal combustion engine having a strong correlation with the temperature of the exhaust pipe 7 or the element temperature of the oxygen sensor 14,
The intake air amount Q detected through the air flow meter 2 is adopted.

However, in addition to the load of the internal combustion engine having a strong correlation with these temperatures, the same air amount Q is used as the rotation speed N.
a basic fuel injection amount Tp proportional to a value divided by e,
Alternatively, there is intake air pressure (intake manifold pressure) Pm or the like.

Therefore, the temperature of the exhaust pipe 7 or the element temperature of the oxygen sensor 14 can be estimated by referring to these values. In any of these cases, it is possible to obtain the same effects as the devices of the above-described embodiments.

When the intake air pressure (intake manifold pressure) Pm is adopted as the load of the internal combustion engine, the intake pressure (intake manifold pressure) sensor 17 as indicated by the broken line in FIG. 1 is used. Will be done.

[0273]

As described above, according to the present invention, in the system in which the heater-equipped oxygen sensor is arranged also on the downstream side of the catalytic converter, the element crack of the oxygen sensor can be prevented more easily and surely. You will be able to.

Further, according to the present invention, since there is no concern that the heater of the oxygen sensor is frequently energized / deenergized, the function of the oxygen sensor arranged on the downstream side of the catalytic converter is also improved. Fully fulfilled while in the active state.

Further, according to the present invention, the management of the response delay until the oxygen sensor is activated is also accurately executed. Also in this sense, the oxygen sensor provided on the downstream side of the catalytic converter can sufficiently perform its function, and the oxygen sensor can always be used in an optimum state.

Therefore, by using the oxygen sensor arranged on the downstream side of the catalytic converter, it is possible to correct the variation or deterioration of the output characteristics of the oxygen sensor on the upstream side of the catalytic converter, or diagnose the deterioration of the purification rate of the catalytic converter. Even when it is performed, it is possible to preferably ensure the accuracy of the correction and diagnosis.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of a management device for an oxygen sensor with a heater according to the present invention.

FIG. 2 is a cross-sectional view showing the structure of the oxygen sensor with a heater shown in FIG.

FIG. 3 is a block diagram showing a functional configuration of a control device of the device of the first embodiment.

FIG. 4 is a flowchart showing a processing procedure for heater energization processing by the apparatus of the first embodiment.

FIG. 5 is a flowchart showing a processing procedure for heater deenergization processing by the apparatus of the first embodiment.

FIG. 6 is a timing chart showing how heaters are energized and how heaters are deenergized by the device of the first embodiment.

FIG. 7 is a flowchart showing a processing procedure of oxygen sensor activity determination processing by the apparatus of the first embodiment.

FIG. 8 is a timing chart showing an activity determination mode of the oxygen sensor by the device of the first embodiment.

FIG. 9 is a block diagram showing a functional configuration of a control device of a second embodiment of the management device for an oxygen sensor with a heater according to the present invention.

FIG. 10 is a flowchart showing a processing procedure for heater energization processing by the apparatus of the second embodiment.

FIG. 11 is a timing chart showing how the heater is energized by the device of the second embodiment.

FIG. 12 is a block diagram showing a functional configuration of a control device of a third embodiment of a management device for an oxygen sensor with a heater according to the present invention.

FIG. 13 is a flowchart showing a processing procedure for heater energization / heater deenergization processing by the apparatus of the third embodiment.

FIG. 14 is a timing chart showing a heater energization / heater deenergization mode by the device of the third embodiment.

FIG. 15 is a block diagram showing a functional configuration of a control device of a fourth embodiment of a management device for an oxygen sensor with a heater according to the present invention.

FIG. 16 is a flowchart showing a processing procedure of oxygen sensor activity determination processing by the apparatus according to the fourth embodiment.

FIG. 17 is a timing chart showing an activity determination mode of the oxygen sensor by the device of the fourth embodiment.

FIG. 18 is a block diagram showing a functional configuration of a control device of a fifth embodiment of the management device for an oxygen sensor with a heater according to the present invention.

FIG. 19 is a flowchart showing a processing procedure of oxygen sensor activity determination processing by the apparatus of the fifth embodiment.

FIG. 20 is a timing chart showing an activity determination mode of the oxygen sensor by the device of the fifth embodiment.

FIG. 21 is a block diagram showing a functional configuration of a control device of a sixth embodiment of the management device for an oxygen sensor with a heater according to the present invention.

FIG. 22 is a flow chart showing the processing procedure of oxygen sensor activity determination processing by the apparatus of the sixth embodiment.

FIG. 23 is a timing chart showing an activity determination mode of the oxygen sensor by the device of the sixth embodiment.

FIG. 24 is a graph mainly showing element temperature characteristics of an oxygen sensor with a standard heater and an oxygen sensor with a low-power heater, with respect to changes in exhaust pipe temperature.

FIG. 25 is a block diagram showing a functional configuration of a control device of a seventh embodiment of the management device for an oxygen sensor with a heater according to the present invention.

FIG. 26 is a flowchart showing a processing procedure of oxygen sensor activity determination processing by the apparatus of the seventh embodiment.

FIG. 27 is a flowchart showing a processing procedure of oxygen sensor inactivity determination processing by the apparatus of the seventh embodiment.

FIG. 28 is a timing chart showing how the oxygen sensor according to the seventh embodiment determines whether the oxygen sensor is active or inactive.

FIG. 29 is a block diagram showing a functional configuration of a control device of an eighth embodiment of the management device for an oxygen sensor with a heater according to the present invention.

FIG. 30 is a flowchart showing a processing procedure of oxygen sensor activity determination processing by the apparatus of the eighth embodiment.

FIG. 31 is a timing chart showing an activity determination mode of the oxygen sensor by the device of the eighth embodiment.

FIG. 32 is a block diagram showing a functional configuration of a control device of a ninth embodiment of the management device for an oxygen sensor with a heater according to the present invention.

FIG. 33 is a flowchart showing a processing procedure of oxygen sensor activation / deactivation determination processing by the apparatus of the ninth embodiment.

FIG. 34 is a timing chart showing an active / inactive determination mode of the oxygen sensor according to the device of the ninth embodiment.

[Explanation of symbols]

1 ... Air cleaner, 2 ... Air flow meter, 3 ... Intake pipe, 4 ... Surge tank, 5 ... Intake manifold,
6 ... Fuel injection valve, 7 ... Exhaust pipe, 8 ... Catalytic converter, 9
... Throttle valve, 10 ... Throttle opening sensor, 1
1 ... Idle switch, 12 ... Rotation speed sensor, 13, 1
4 ... Oxygen sensor with heater, 15 ... Intake valve, 16 ... Exhaust valve, 17 ... Intake pressure (intake manifold pressure) sensor, 20 ... Control device, 21 ... CPU, 22 ... ROM, 2
3 ... RAM, 24 ... Backup RAM, 25 ... Input / output port (I / O port), 31 ... Cover, 32 ... Sensor element, 33 ... Heater, 201 ... High intake air quantity determination unit, 202
… Integration timer, 202 ′ ... Air amount integration unit, 203, 20
3 '... energization ON determination unit, 204 ... energization control unit, 205 ...
Idle determination unit, 206 ... Idle timer, 207 ... Energization off determination unit, 208 ... Up / down timer, 209
... energization on / off determination unit, 210 ... energization flag memory,
211 ... Energization determination unit, 212 ... Energization timer, 213 ... Activation determination unit, 214 ... Permission flag management unit, 220 ... Control permission flag memory, 221 ... Control circuit, 230 ... Diagnostic permission flag memory, 231 ... Diagnostic circuit, 240, 240 ',
241 ... Activity determination unit, 251, 251 '... Activity determination unit,
252 ... Inactivity determination section, 253 ... Active / inactivity determination section.

Claims (20)

[Claims] 1. A device for managing the state of an oxygen sensor with a heater arranged downstream of a catalytic converter in an exhaust system of an internal combustion engine, comprising: load calculating means for calculating a load of an internal combustion engine; Is a time equal to or greater than a predetermined value, and a time integrating means for energizing the heater of the oxygen sensor on condition that the integrated time reaches a predetermined time corresponding to the moisture non-generation temperature of the exhaust pipe of the internal combustion engine. An oxygen sensor management device with a heater, comprising: an energization control means for performing the operation. 2. An apparatus for managing the state of an oxygen sensor with a heater arranged downstream of a catalytic converter in an exhaust system of an internal combustion engine, comprising: load calculating means for calculating a load of an internal combustion engine; Is a predetermined value or more, load amount integrating means for integrating the load amount, and the oxygen is provided under the condition that the integrated load amount reaches a predetermined load amount corresponding to the moisture non-generation temperature of the internal combustion engine exhaust pipe. An oxygen sensor management device with a heater, comprising: an energization control means for energizing the heater of the sensor. 3. An oxygen sensor management device with a heater according to claim 1, wherein idle determination means for performing idle determination of the internal combustion engine and the idle determination time is maintained for a predetermined time. 2. A management apparatus for an oxygen sensor with a heater, further comprising: energization release control means for resetting the integrated value and deenergizing the heater of the oxygen sensor. 4. A device for managing the state of an oxygen sensor with a heater arranged downstream of a catalytic converter in an exhaust system of an internal combustion engine, comprising load calculating means for calculating the load of the internal combustion engine, and the calculated load. When the load is less than a predetermined value, the up / down timer counts down when the load is less than the predetermined value, and this timer value reaches a predetermined value corresponding to the moisture non-occurrence temperature of the internal combustion engine exhaust pipe. On the condition that the heater of the oxygen sensor is energized and the timer value is less than the predetermined value, an energization control means for canceling the energization of the heater of the oxygen sensor is provided. Oxygen sensor management device with a characteristic heater. 5. The heater oxygen sensor management device according to claim 4, wherein the up / down timer has a relation of Up> Down when the up count value is Up and the down count value is Down. A management device for an oxygen sensor with a heater, wherein each count value is set. 6. An oxygen sensor management device with a heater according to any one of claims 1 to 5, further comprising an energization time measuring means for measuring an energization time of the oxygen sensor on condition that the heater of the oxygen sensor is energized. A heater characterized by further comprising: an activity management means for permitting the use of the oxygen sensor, provided that the measured time is equal to or longer than a predetermined time corresponding to the activation temperature of the oxygen sensor. Oxygen sensor management device. 7. The oxygen sensor management device with a heater according to claim 1, wherein the heater of the oxygen sensor is energized, and the time accumulated by the time integrating means is the active temperature of the oxygen sensor. The management device for an oxygen sensor with a heater, further comprising an activity management means for permitting the use of the oxygen sensor on condition that the oxygen sensor is used for a predetermined time or more. 8. The management device for an oxygen sensor with a heater according to claim 2 or 3, wherein the heater of the oxygen sensor is energized, and the load amount accumulated by the load amount accumulating means is equal to that of the oxygen sensor. A management device for an oxygen sensor with a heater, further comprising an activity management means for permitting the use of the oxygen sensor on condition that the load is equal to or higher than a predetermined load amount corresponding to the activation temperature. 9. The management device for an oxygen sensor with a heater according to claim 4, wherein the heater of the oxygen sensor is energized, and the count value of the up / down counter corresponds to the activation temperature of the oxygen sensor. A device for managing an oxygen sensor with a heater, further comprising an activity management means for permitting the use of the oxygen sensor on condition that the oxygen sensor is above a predetermined value. 10. The load of the internal combustion engine is an intake air amount to the internal combustion engine, and the load calculating means is an intake air amount calculating means for calculating a value of the intake air amount each time. 10. The management device for an oxygen sensor with a heater according to any one of 9 to 9. 11. The load of the internal combustion engine is a fuel basic injection amount to the internal combustion engine, and the load calculating means is a fuel basic injection amount calculating means for calculating a value of the fuel basic injection amount each time. The management device for an oxygen sensor with a heater according to claim 1. 12. The load of the internal combustion engine is an intake air pressure to the internal combustion engine, and the load calculating means is an intake air pressure calculating means for calculating a value of the intake air pressure each time. An oxygen sensor management device with a heater according to any one of the claims. 13. A device for managing the state of an oxygen sensor with a heater arranged downstream of a catalytic converter in an exhaust system of an internal combustion engine, comprising load calculating means for calculating a load of an internal combustion engine, and the calculated load. And a management means for permitting the use of the oxygen sensor on the condition that the accumulated time reaches a predetermined time corresponding to the activation temperature of the oxygen sensor. An oxygen sensor management device with a heater, comprising: 14. A device for managing the state of an oxygen sensor with a heater arranged downstream of a catalytic converter in an exhaust system of an internal combustion engine, comprising load calculating means for calculating a load of an internal combustion engine, and the calculated load. And a load amount accumulating means for accumulating the load amount when the oxygen sensor is equal to or more than a predetermined value, and the use of the oxygen sensor provided that the accumulated load amount reaches a predetermined load amount corresponding to the activation temperature of the oxygen sensor. An oxygen sensor management device with a heater, comprising: 15. The management device for an oxygen sensor with a heater according to claim 13 or 14, wherein idle determination means for performing idle determination of the internal combustion engine, and the idle determination time is maintained for a predetermined time. 2. A management device for an oxygen sensor with a heater, further comprising: a prohibition unit that resets the integrated value and prohibits the use of the oxygen sensor. 16. A device for managing the state of an oxygen sensor with a heater arranged downstream of a catalytic converter in an exhaust system of an internal combustion engine, comprising: load calculating means for calculating the load of the internal combustion engine; and the calculated load. Is counted above a predetermined value, and an up / down timer that counts down when the load is less than a predetermined value, and a condition that this timer value reaches a predetermined value corresponding to the activation temperature of the oxygen sensor. A management means for permitting the use of the oxygen sensor and prohibiting the use of the oxygen sensor on the condition that the timer value is less than the predetermined value. Management device. 17. The management device for an oxygen sensor with a heater according to claim 16, wherein the up / down timer has a relation of Up> Down when the up count value is Up and the down count value is Down. A management device for an oxygen sensor with a heater, wherein each count value is set. 18. The load of the internal combustion engine is an intake air amount to the internal combustion engine, and the load calculating means is an intake air amount calculating means for calculating a value of the intake air amount each time. 18. An oxygen sensor management device with a heater according to any one of items 1 to 17. 19. The load of the internal combustion engine is a basic fuel injection amount into the internal combustion engine, and the load calculating means is a basic fuel injection amount calculating means for calculating a value of the basic fuel injection amount each time. The oxygen sensor management device with a heater according to claim 13. 20. The load of the internal combustion engine is an intake air pressure to the internal combustion engine, and the load calculating means is an intake air pressure calculating means for calculating a value of the intake air pressure each time. An oxygen sensor management device with a heater according to any one of the claims.