JP2003065027A - Control device for exhaust air temperature sensor for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to reduce delay in response of a value detected by an exhaust air temperature sensor to changes in actual catalyst temperature, to reduce difference between the actual catalyst temperature and the value detected by the exhaust air temperature sensor, and to detect exhaust air temperature with a high degree of accuracy. SOLUTION: A catalyst for purifying exhaust air is provided in an exhaust air passage in an internal combustion engine. An exhaust air sensor for detecting composition of the exhaust air is provided on the upstream side of the catalyst in the exhaust air passage. The exhaust air temperature sensor for detecting the exhaust air temperature is provided on the downstream side of the catalyst, including the inside of the catalyst, in the exhaust air passage. A heater which generates heat or stops with the power supply being on or off is provided in the exhaust air temperature sensor. And then, control means for controlling switching between on and off of the power supply to the heater, in response to the value of the exhaust air temperature detected by the exhaust air temperature sensor, is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas temperature sensor control device for an internal combustion engine, and more particularly, it can reduce the response delay of the detected value of the exhaust gas temperature sensor with respect to a change in the actual catalyst temperature, thereby reducing the actual catalyst temperature and the actual catalyst temperature. The present invention relates to an exhaust gas temperature sensor control device for an internal combustion engine, which can reduce a difference from a detection value of an exhaust gas temperature sensor and can detect an exhaust gas temperature with high accuracy.

[0002]

2. Description of the Related Art An internal combustion engine mounted on a vehicle is provided with a catalyst for purifying exhaust gas in an exhaust passage and an exhaust temperature sensor for detecting exhaust temperature in the exhaust passage. There is an exhaust temperature sensor control device for controlling the air-fuel ratio of the air-fuel mixture so that the temperature becomes an activation temperature and ensuring the exhaust gas purification function of the catalyst.

Exhaust gas temperature sensor control devices for such internal combustion engines are disclosed in Japanese Patent Laid-Open Nos. 8-35418 and 7-78.
There is one disclosed in Japanese Patent Publication No. 19040.

The one disclosed in Japanese Patent Laid-Open No. 8-35418 predicts the exhaust temperature based on a model constant calculated in real time and an inverse model in which a response delay of the three-way catalyst temperature detecting means is taken into consideration. When the predicted exhaust temperature is lower than the target temperature, it is judged that the three-way catalyst is not activated, and the exhaust gas temperature is controlled to rise.When the predicted exhaust temperature is higher than the target temperature, the three-way catalyst is controlled. It is determined that the catalyst is activated and control of the exhaust gas temperature is stopped.

The device disclosed in Japanese Patent Laid-Open No. 7-19040 is provided with a ventilator for introducing outside air into a hood covering an exhaust pipe, and an opening / closing valve for adjusting the amount of introduced outside air is provided in the ventilator. Is controlled to an optimum opening degree corresponding to the engine speed, the exhaust gas temperature, and the outside air temperature, so that the exhaust gas temperature is optimized.

[0006]

By the way, the exhaust gas temperature sensor control device is provided with an exhaust gas temperature sensor in the exhaust gas passage including the inside of the catalyst and downstream from the catalyst, and the catalyst temperature is activated by the detected value of the exhaust gas temperature sensor. There is one that controls the temperature.

However, when the exhaust temperature sensor is provided in the exhaust passage from the inside of the catalyst to the downstream side, there is a delay or difference in the detection of the exhaust temperature with respect to the actual temperature of the catalyst, and the exhaust temperature can be detected with high accuracy. There is no problem.

For example, when the exhaust temperature sensor is provided on the downstream side of the catalyst, as shown in FIG. 5, under the condition that the load of the internal combustion engine is low, the actual temperature of the catalyst and the exhaust temperature sensor on the downstream side of the catalyst are There may be a large difference from the detected value. Further, when the exhaust temperature sensor is provided on the downstream side of the catalyst, as shown in FIG. 6, the actual temperature of the catalyst and the detected value of the exhaust temperature sensor on the downstream side of the catalyst are detected even under the condition that the load of the internal combustion engine is high. There is a problem that a difference may occur between the two, and the response of the detected value of the exhaust gas temperature sensor to the actual temperature of the catalyst is delayed.

Therefore, when the detected value of the exhaust temperature of the response delay is used for the control of the internal combustion engine, the control of the air-fuel ratio and the ignition timing of the internal combustion engine is delayed, which accelerates the deterioration of the catalyst. There is a risk. Further, when the response delay of the exhaust gas temperature sensor is corrected for the purpose of preventing the deterioration of the catalyst, there is a problem that the catalyst deterioration prevention control must be performed even if the catalyst deterioration prevention control is unnecessary.

[0010]

In order to eliminate the above-mentioned inconvenience, therefore, the present invention provides an exhaust gas purification catalyst in the exhaust passage of an internal combustion engine, and detects the exhaust gas composition in the exhaust passage upstream of this catalyst. An exhaust gas sensor is provided, and an exhaust gas temperature sensor for detecting the exhaust gas temperature is provided in an exhaust passage downstream from the catalyst including the inside of the catalyst.
A heater that heats and stops when turned off is provided, and a control unit that controls to turn on / off the power of the heater according to a detected value of the exhaust temperature detected by the exhaust temperature sensor is provided.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An exhaust gas temperature sensor control apparatus for an internal combustion engine according to the present invention is provided with an exhaust gas temperature sensor in an exhaust passage including a inside of a catalyst and downstream of the catalyst, and turning on / off a power source in the exhaust gas temperature sensor. A heater for heating and stopping is provided, and the control means controls the power source of the heater to be turned on / off in accordance with the detected value of the exhaust temperature detected by the exhaust temperature sensor, thereby making the exhaust temperature sensor a heater based on the exhaust temperature. By heating with, the detected value of the exhaust temperature sensor can be made closer to the actual temperature of the catalyst, the response of the detected value of the exhaust temperature sensor to the actual temperature of the catalyst is delayed, and the actual temperature of the catalyst The difference from the value detected by the exhaust temperature sensor can be reduced.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show an embodiment of the present invention. In FIG. 3, 2 is an internal combustion engine, and 4 is a combustion chamber. The internal combustion engine 2 sequentially connects an air cleaner (not shown), an intake pipe 6, a throttle body 8 and an intake manifold 10, and has an intake passage 12 communicating with each combustion chamber 4. A throttle valve 14 is provided in the intake passage 12 of the throttle body 8. The intake manifold 10
A fuel injection valve 16 is provided for each combustion chamber 4.

Further, the internal combustion engine 2 has an exhaust manifold 18
And the exhaust pipe 20 and the catalytic converter 22 are sequentially connected,
An exhaust passage 24 communicating with each combustion chamber 4 is provided. The catalytic converter 22 is provided with an exhaust purification catalyst 26 in an exhaust passage 24. The exhaust pipe 20 upstream of the catalyst 26
An oxygen sensor 28 (O ₂ sensor) that detects the oxygen concentration of the exhaust gas is provided as an exhaust gas sensor that faces the exhaust passage 24 and detects the exhaust gas composition. The exhaust sensor may be an air-fuel ratio sensor that detects the air-fuel ratio of exhaust gas. Further, the internal combustion engine 2 is provided with an ignition plug 30 facing each combustion chamber 4.

The internal combustion engine 2 is provided with an exhaust temperature sensor 32 that detects the exhaust temperature in the exhaust passage 24 that is located inside the catalyst 26 and that is downstream of the catalyst 26. In this embodiment, an exhaust temperature sensor 32 is provided so as to face the exhaust passage 24 immediately after the catalyst 26.

As shown in FIG. 4, the exhaust temperature sensor 32 is provided with a temperature detecting element 36 located in the exhaust passage 24 on one end side of the sensor body 34, and a bottomed cylindrical element cover 38 for covering the temperature detecting element 36. And the element cover 38 is provided with a plurality of through holes 40 through which the exhaust gas flows. A sensor output line 42 that outputs the detected signal is connected to the temperature detection element 36. The sensor output line 42 is connected to the sensor body 34.
Is derived from.

In the exhaust temperature sensor 32, the power source O
A heater 44 that heats and stops when N / OFF is provided. The heater 44 is provided so as to cover the outer periphery of the temperature detection element 36, and is connected to a heater power supply line 46 that supplies power. The heater power supply line 46 is led out from the other end side of the sensor body 34.

The fuel injection valve 16, the oxygen sensor 28, the spark plug 30, the exhaust temperature sensor 32, and the heater 44 are connected to the control means 50 of the exhaust temperature sensor control device 48. The control means 50 includes an engine speed sensor 52 for detecting an engine speed, a throttle opening sensor 54 for detecting a throttle opening, an intake pressure sensor 56 for detecting an intake negative pressure, and a water temperature sensor 58 for detecting a cooling water temperature. And a vehicle speed sensor 60 for detecting the vehicle speed are connected.

The control means 50 includes various sensors 32, 52 ...
The signal input from 60 controls the operation of the fuel injection valve 16 and the ignition of the spark plug 30 to perform air-fuel ratio control and ignition timing control.

The control means 50 includes an exhaust temperature sensor 32.
The power of the heater 44 is controlled to be turned on and off according to the detected value of the exhaust temperature detected by the above.

Further, the control means 50 includes the internal combustion engine 2
A warm-up completion detecting means 62 for detecting the completion of warm-up is provided. The warm-up completion detecting means 62 detects that the warm-up of the internal combustion engine 2 has been completed by the signals input from the various sensors 52 to 60.

Further, the control means 50 is provided by setting first to fifth set values T0 to T4 as shown in FIG. 2 with respect to the detected value of the exhaust temperature detected by the exhaust temperature sensor 32. There is. The first to fifth set values T0 to T4 are T0 <T1
The relationship of <T2 <T4 <T3 is set.

The first set value T0 is a heater control lower limit threshold value (eg, 500 ° C.), and the exhaust temperature sensor 32
When the detected value of is less than or equal to the lower limit threshold value of the heater control, the power of the heater 44 is turned off. The second set value T1 is a heater control ON threshold value (for example, 700 ° C.), and when the detected value of the exhaust temperature sensor 32 is less than this heater control ON threshold value, the power of the heater 44 is turned ON. The third set value T2 is a heater control OFF threshold value (for example, 73
If the detected value of the exhaust gas temperature sensor 32 exceeds the heater control OFF threshold value, the power source of the heater 44 is turned off.

The fourth set value T3 is a catalyst protection control ON threshold value (for example, 900 ° C.), and the exhaust temperature sensor 3
When the detected value of 2 exceeds the catalyst protection control ON threshold value, the temperature of the catalyst 26 is controlled to be lowered. The fifth set value T4 is a catalyst protection control OFF threshold value (for example,
850 ° C.) and the detected value of the exhaust gas temperature sensor 32 is less than the catalyst protection control OFF threshold value, the control for lowering the temperature of the catalyst 26 is terminated.

The control means 50 includes the warm-up completion detecting means 6
When the completion of warming up of the internal combustion engine 2 is detected by 2, the detected value of the exhaust gas temperature detected by the exhaust gas temperature sensor 32 exceeds the first set value T0 and is higher than the first set value T0. If it is less than the set value T1 of 2, the power of the heater 44 is controlled to be turned on, and the detected value of the exhaust temperature detected by the exhaust temperature sensor 32 is higher than the second set value T1. If it exceeds the limit, turn on the power of the heater 44.
Control to FF.

Further, when the warm-up completion detecting means 62 detects the warm-up completion of the internal combustion engine 2, the control means 50 sets the detected value of the exhaust temperature detected by the exhaust temperature sensor 32 to the first set value. If it exceeds T0 and exceeds the fourth set value T3 which is higher than the first set value T0, the catalyst 2
The temperature of 6 is controlled to be lowered. At this time, the control means 50 controls the air-fuel ratio of the air-fuel mixture to be the air-fuel ratio on the rich side of the stoichiometric air-fuel ratio so as to lower the temperature of the catalyst 26.

The control means 50 includes the exhaust temperature sensor 3
If the detected value of the exhaust gas temperature detected by No. 2 becomes less than the fifth set value T4 after exceeding the fourth set value T3, the catalyst 2
The control for lowering the temperature of 6 is terminated.

Next, the operation will be described.

Exhaust temperature sensor control device 48 for internal combustion engine 2
When the control means 50 starts the control (100) as shown in FIG. 1, the various sensors 32.
Signals such as exhaust temperature and engine speed from
2) Based on these signals, it is determined whether the internal combustion engine 2 has been warmed up (104).

If this judgment (104) is YES, it is judged whether the detected value of the exhaust gas temperature detected by the exhaust gas temperature sensor 32 exceeds the first set value T0 (106).
When this determination (106) is YES, it is determined whether the detected value of the exhaust temperature sensor 32 is less than the fourth set value T3 (108). When this determination (108) is YES, it is determined whether the detected value of the exhaust temperature sensor 32 is less than the second set value T1 (110).

If this judgment (110) is YES, the heater 4 provided in the exhaust temperature sensor 32 is controlled by the heater.
4 is turned on (112), and various sensors 32 / 52-
A signal is taken from 60 (114), and the exhaust temperature sensor 3
It is determined whether the detected value of 2 exceeds the third set value T2 (116).

When the judgment (116) is NO, the process returns to the process (112) and the heater 44 is turned on. If this judgment (116) is YES, the power supply of the heater 44 is turned off to end the heater control (118). In addition,
If the judgments (104), (106) and (110) are NO, the end is made (118).

When the judgment (108) is NO, the catalyst protection control is started (120) to control the temperature of the catalyst 26 to be lowered, and the various sensors 32, 52-60.
(122), and it is determined whether the detected value of the exhaust gas temperature sensor 32 exceeds the fifth set value T4 (1).
24).

In the catalyst protection control (120), the fuel injection valve 16 is controlled so that the air-fuel ratio of the air-fuel mixture becomes an air-fuel ratio on the rich side (fuel excess state) of the stoichiometric air-fuel ratio. This lowers the temperature of the catalyst 26.

If the determination (124) is NO, the process returns to the process (120), and the catalyst protection control is performed to lower the temperature of the catalyst 26. The judgment (124) is YE
In the case of S, the catalyst protection control is ended (126) and the catalyst 2
The control for lowering the temperature of No. 6 is terminated and brought to an end (118).

The catalyst protection control is completed (126).
In the above, the control for lowering the temperature of the catalyst 26 is ended by changing the air-fuel ratio of the air-fuel mixture from the rich-side air-fuel ratio to the stoichiometric air-fuel ratio.

As described above, the exhaust temperature sensor control device 48 of the internal combustion engine 2 turns on / off the power source of the heater 44 by the control means 50 according to the detected value of the exhaust temperature detected by the exhaust temperature sensor 32. Control.

In this embodiment, the exhaust gas temperature sensor control device 48 uses the warm-up completion detecting means 62 for the internal combustion engine 2
When the completion of warming up is detected, the detected value of the exhaust gas temperature detected by the exhaust gas temperature sensor 32 exceeds the first set value T0 and is higher than the first set value T0. When it is less than the above, when the power of the heater 44 is controlled to be turned on, and the detected value of the exhaust gas temperature detected by the exhaust gas temperature sensor 32 exceeds the third set value T2 which is higher than the second set value T1. Controls to turn off the power of the heater 44.

As a result, the exhaust temperature sensor control device 48
Uses the exhaust temperature sensor 32 to set the heater 44 based on the exhaust temperature.
By heating at, the detection value of the exhaust gas temperature sensor 32 can be brought close to the actual temperature of the catalyst 26,
It is possible to reduce the delay in the response of the detected value of the exhaust temperature sensor 32 to the actual temperature of the catalyst 26 and the difference between the actual temperature of the catalyst 26 and the detected value of the exhaust temperature sensor 32.

Therefore, the exhaust temperature sensor control device 4
8 is an exhaust gas temperature sensor 3 for an actual change in the catalyst temperature.
The response delay of the detected value of 2 can be reduced, the difference between the actual catalyst temperature and the detected value of the exhaust temperature sensor 32 can be reduced, and the exhaust temperature can be detected with high accuracy.

As a result, the exhaust temperature sensor control device 4
No. 8 does not cause a delay in control even when used for controlling the air-fuel ratio or ignition timing of the internal combustion engine 2, can avoid the possibility of accelerating the deterioration of the catalyst 26, and deteriorates the deterioration of the catalyst 26. The catalyst deterioration prevention control for correcting the response delay of the exhaust temperature sensor 32 for the purpose of prevention can be eliminated, and the control can be simplified.

Moreover, the exhaust temperature sensor control device 48
Indicates that the heater 44 is turned on in the temperature range (the range from the first set value T0 to the third set value T2) in which the exhaust purification catalyst 26 most effectively purifies the exhaust, and thus wasteful power is consumed. Since it is not consumed, the charging system of the internal combustion engine 2 is not burdened. Further, the exhaust temperature sensor control device 48 can improve the accuracy of the detection value of the exhaust temperature sensor 48, and can perform the air-fuel ratio control of the air-fuel mixture by using a value close to the actual catalyst temperature. It is possible to realize a control device that excels in exhaust gas purification performance and consumes less fuel.

Further, the exhaust temperature sensor control device 48
Is the first set value T when the detected value of the exhaust gas temperature detected by the exhaust gas temperature sensor 32 is detected by the control means 50 when the warm-up completion detection means 62 detects the completion of warm-up of the internal combustion engine 2.
When it exceeds 0 and exceeds the fourth set value T3 which is higher than the first set value T0, the air-fuel ratio of the air-fuel mixture is set to an air-fuel ratio richer than the stoichiometric air-fuel ratio, so that the catalyst 2
The temperature of 6 is controlled to be lowered.

As a result, the exhaust gas temperature sensor control device 48 controls the heater 44 in a certain temperature range (first set value T0).
From the third set value T2), the temperature of the catalyst 26 does not become too high, and the catalyst 2
It is possible to avoid the high temperature deterioration of No. 6 and maximize the theoretical air-fuel ratio operation region with good fuel consumption efficiency.

Further, the exhaust temperature sensor control device 48
When the detected value of the exhaust temperature sensor 32 exceeds the fourth set value T3, the temperature of the catalyst 26 is lowered by setting the air-fuel ratio of the air-fuel mixture to the rich side air-fuel ratio. It is possible to realize the temperature decrease of the catalyst 26 only by changing the program of the control system without requiring the cooling means of FIG. When the detected value of the exhaust temperature detected by the exhaust temperature sensor 32 becomes equal to or lower than the fifth set value T4, the air-fuel ratio of the air-fuel mixture is returned from the rich side air-fuel ratio to the stoichiometric air-fuel ratio, so The component value can be lowered.

Furthermore, in the exhaust gas temperature sensor control device 48, the detected value of the exhaust gas temperature sensor 32 is the fourth set value T.
If it becomes less than the fifth set value T4 after exceeding 3,
By ending the control for lowering the temperature of the catalyst 26, high temperature deterioration of the catalyst 26 can be avoided and the service life can be extended.

In the above embodiment, the exhaust temperature sensor 32 is provided so as to face the exhaust passage 24 immediately after the catalyst 26, but the exhaust temperature sensor 32 may be provided inside the catalyst 26. Further, in the above-described embodiment, the power supply of the heater 44 is controlled to be turned on / off according to the detected value of the exhaust temperature detected by the exhaust temperature sensor 32, but in order to prevent the heater 44 from being frequently turned on / off. Hysteresis can be provided in the ON / OFF control. Further, when it is clearly determined that the temperature of the catalyst 26 does not enter the high temperature condition (for example, during idle operation or during traffic congestion), the exhaust temperature sensor controller 48 controls the heater 44 of the exhaust temperature sensor 32. It can also be removed from.

Further, the exhaust temperature sensor control device 48 of the internal combustion engine 2 controls to turn on / off the power of the heater 44 according to the detected value of the exhaust temperature detected by the exhaust temperature sensor 32. 2 for different operating conditions
6 learns the difference between the actual temperature and the detection value of the exhaust temperature sensor 32 and the response delay, and learns the difference between the actual temperature of the catalyst 26 and the response delay of the exhaust temperature sensor 32 in the current operating state. Predicted from ON, turn on heater 44
By controlling the temperature to F, the detected value of the exhaust gas temperature sensor 32 can be brought closer to the actual temperature of the catalyst 26, and the exhaust gas temperature sensor 3 with respect to the actual temperature of the catalyst 26 can be made.
It is possible to reduce the difference between the detection values of 2 and the delay of the response,
It may be possible to detect the exhaust temperature with high accuracy.

Further, the exhaust gas temperature sensor control device 48 of the internal combustion engine 2 controls to turn on / off the power of the heater 44 according to the detected value of the exhaust gas temperature detected by the exhaust gas temperature sensor 32. The actual temperature of the catalyst 26 is estimated from the oxygen concentration of the exhaust gas detected by the heater 44.
By controlling to turn on / off the catalyst 26
Of the exhaust gas temperature sensor 32 can be brought closer to the actual temperature of the catalyst 26, and the difference in the detected value of the exhaust gas temperature sensor 32 with respect to the actual temperature of the catalyst 26 and the delay of the response can be reduced. It may allow detection of temperature.

Furthermore, an ON / OFF map for the heater 44 is created from the operating conditions, the outside air temperature, the fuel injection amount, etc.
Turns on the exhaust temperature detection value detected by the exhaust temperature sensor 32.
-Turn on the power of the heater 44 by referring to the OFF map.
By controlling to turn off the N / OFF, the detected value of the exhaust temperature sensor 32 can be brought close to the actual temperature of the catalyst 26, and the heater 44 is supplied with a power source capable of heating the exhaust temperature sensor 32 to a specific temperature. By detecting the detection characteristic of the exhaust gas temperature sensor 32 from the difference between the temperature detected by the exhaust gas temperature sensor 32 and the specific temperature, the control is performed so as to correct the temperature of the exhaust gas actually detected according to this detection characteristic. , A temperature close to the actual temperature of the catalyst 26 can be obtained with high accuracy.

[0050]

As described above, the exhaust gas temperature sensor control device for an internal combustion engine according to the present invention detects the exhaust gas temperature sensor with respect to the actual temperature of the catalyst by heating the exhaust gas temperature sensor with the heater based on the exhaust gas temperature. The values can be made close to each other, and the delay in the response of the detected value of the exhaust temperature sensor to the actual temperature of the catalyst and the difference between the actual temperature of the catalyst and the detected value of the exhaust temperature sensor can be reduced.

Therefore, the exhaust temperature sensor control device can reduce the response delay of the detected value of the exhaust temperature sensor with respect to the actual change of the catalyst temperature, and the difference between the actual catalyst temperature and the detected value of the exhaust temperature sensor can be reduced. Can be reduced, and the exhaust gas temperature can be detected with high accuracy. As a result, this exhaust gas temperature sensor control device does not cause a delay in control even when used for controlling the air-fuel ratio or ignition timing of the internal combustion engine, and can avoid the possibility of promoting catalyst deterioration, Also,
The catalyst deterioration prevention control for correcting the response delay of the exhaust gas temperature sensor for the purpose of preventing the catalyst deterioration can be dispensed with, and the control can be simplified.

[Brief description of drawings]

FIG. 1 is a control flowchart of an exhaust gas temperature sensor control device for an internal combustion engine showing an embodiment of the present invention.

FIG. 2 is a diagram illustrating a relationship between a set value and ON / OFF of a heater.

FIG. 3 is a system configuration diagram of an exhaust gas temperature sensor control device for an internal combustion engine.

FIG. 4 is a partially cutaway side view of an exhaust temperature sensor.

FIG. 5 is a diagram showing a relationship between a catalyst internal temperature and a detection value of an exhaust temperature sensor when a load is low.

FIG. 6 is a diagram showing a relationship between a catalyst internal temperature and a detection value of an exhaust temperature sensor under a high load.

[Explanation of symbols]

2 Internal combustion engine 4 Combustion chamber 12 Intake passage 14 Throttle valve 16 Fuel injection valve 24 exhaust passage 26 catalyst 28 oxygen sensor 30 spark plug 32 Exhaust temperature sensor 44 heater 48 Exhaust temperature sensor control device 50 control means 52 Engine speed sensor 54 Throttle opening sensor 56 Intake pressure sensor 58 Water temperature sensor 60 vehicle speed sensor 62 Warm-up completion detecting means

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F01N 9/00 F02D 35/00 360C F02D 35/00 360 41/04 305A 41/04 305 330M 330 B01D 53 / 36 B F term (reference) 3G004 AA01 BA06 BA09 DA25 3G091 AA02 AA17 AA23 AA28 AB01 BA02 BA03 BA04 BA05 BA28 CA05 CB02 CB05 DA01 DA02 DB11 EA01 EA06 EA07 EA16 EA17 EA34 EA39 FA02 FA04 FB02 FB03 FB11 FB12 FC04 FC07 FC08 HA36 HA37 HA38 3G301 HA01 HA06 JA08 JA13 JA20 JA21 JA25 JA26 JA33 KA05 KA11 KA21 LA01 LB02 MA01 MA11 NA07 NA08 NB18 ND01 NE13 PA07B PA07Z PA11B PA11Z PD02B PD02Z PD11B PD11Z PE01B PE01Z PE08B PE08Z PF01B PF01Z 4D08 DA03 DA53 DA0348 DA53

Claims (4)

[Claims] 1. An exhaust gas purification catalyst is provided in an exhaust passage of an internal combustion engine, and an exhaust sensor for detecting an exhaust gas composition is provided in an exhaust passage upstream of the catalyst. An exhaust gas temperature sensor for detecting the exhaust gas temperature is provided in the passage, and a heater for generating heat and stopping by turning the power supply on and off is provided in the exhaust gas temperature sensor, and the heater is provided according to the detected value of the exhaust gas temperature detected by the exhaust gas temperature sensor. 2. An exhaust gas temperature sensor control device for an internal combustion engine, comprising: a control means for controlling to turn on / off the power of the engine. 2. An exhaust gas purifying catalyst is provided in an exhaust passage of an internal combustion engine, and an exhaust sensor for detecting an exhaust gas composition is provided in an exhaust passage on an upstream side of the catalyst, and an exhaust gas downstream from the catalyst including the inside of the catalyst is provided. An exhaust temperature sensor for detecting the exhaust temperature is provided in the passage, a heater for generating heat and stopping by turning on / off the power source is provided in the exhaust temperature sensor, and warm-up completion detecting means for detecting completion of warm-up of the internal combustion engine is provided. When the completion of warming up of the internal combustion engine is detected by the completion of warming up detection means,
The detected value of the exhaust gas temperature detected by the exhaust gas temperature sensor is the first
Is greater than the first set value and less than the second set value which is higher than the first set value, the heater power is controlled to be turned on, and the detected value of the exhaust temperature detected by the exhaust temperature sensor is An exhaust gas temperature sensor control device for an internal combustion engine, comprising control means for controlling to turn off the power source of the heater when a third set value higher than the second set value is exceeded. 3. An exhaust gas purifying catalyst is provided in an exhaust passage of an internal combustion engine, and an exhaust sensor for detecting an exhaust gas composition is provided in an exhaust passage on an upstream side of the catalyst, and an exhaust gas downstream of the catalyst including the inside of the catalyst is provided. An exhaust temperature sensor for detecting the exhaust temperature is provided in the passage, a heater for generating heat and stopping by turning on / off the power source is provided in the exhaust temperature sensor, and warm-up completion detecting means for detecting completion of warm-up of the internal combustion engine is provided. When the completion of warming up of the internal combustion engine is detected by the completion of warming up detection means,
The detected value of the exhaust gas temperature detected by the exhaust gas temperature sensor is the first
Is exceeded and a fourth set value higher than the first set value is exceeded, control means for controlling the temperature of the catalyst to be lowered is provided. Exhaust temperature sensor control device. 4. The control means, when the completion of warming up of the internal combustion engine is detected by the warming up completion detecting means, the detected value of the exhaust temperature detected by the exhaust temperature sensor exceeds a first set value. If the fourth set value, which is higher than the first set value, is exceeded, the air-fuel ratio of the internal combustion engine is controlled to be the air-fuel ratio richer than the stoichiometric air-fuel ratio so as to lower the temperature of the catalyst. The exhaust gas temperature sensor control device for an internal combustion engine according to claim 3, which is a control means.