JPH06341908A - Temperature abnormality detecting device for vehicle - Google Patents

Abstract

PURPOSE:To provide a temperature abnormality detecting device for vehicle capable of precisely judging a temperature abnormality in an engine room without having the influence of the outside air temperature. CONSTITUTION:The measured temperature gradient in an engine room is determined by the detected temperature of each temperature sensor 1A-1X set in plural parts in the engine room. The respective corresponding differences between these measured temperature gradients and standard gradients in a memory 2 is outputted by a comparing means 3, and a temperature abnormality is judged by a temperature abnormality judging means 4 having the threshold of the temperature difference related to this output as a judgment target according to whether each measured temperature gradient is larger than each standard gradient by a prescribed value or more. The other constitution judges whether a temperature abnormality exists or not on the basis of the difference between the inside air temperature and the outside air temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature abnormality detecting device for an engine room, which is useful for preventing ignition in the engine room or for extinguishing the engine early.

[0002]

2. Description of the Related Art In an engine room formed by a top panel, there are a plurality of portions such as a fuel pump and a carburetor to which fuel is introduced, and these portions are present as ignition sources. In addition, hoses for guiding hydraulic oil also exist as ignition sources in the engine room.

In view of such circumstances, it has been proposed to equip a vehicle with a fire extinguisher. For example, JP-A-57-98.
In the No. 33 publication, a temperature sensor is provided in the engine room in which the nozzle of the fire extinguisher is installed, and an abnormal temperature in the engine room is detected by the temperature detected by the temperature sensor,
It is disclosed to activate the fire extinguisher automatically.

[0004]

The conventional temperature abnormality detecting device detects an abnormality when the temperature inside the engine room exceeds a threshold temperature at which a fire is judged. However, the inside temperature of the engine room fluctuates under the influence of the outside temperature. For example, the inside temperature is high in summer and low in winter. Therefore, the inside temperature when a fire actually occurs will also be affected by the outside temperature, and if the above threshold temperature is set to a lower value, malfunctions that determine temperature abnormalities will increase even at non-fire temperatures, and If it is set, there will be an inconvenience that the temperature will not be judged to be abnormal even in an actual fire.

In consideration of the occurrence of the above problems, in the conventional temperature abnormality detecting device, the threshold temperature is set to a high value to sacrifice the accuracy of judging a fire. Specifically, the threshold temperature to be set is around 150 ° C. As described above, in the conventional temperature abnormality detection device, since the threshold temperature is set to be high, detection of the temperature abnormality tends to be delayed, and it is difficult to extinguish the fire early.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to eliminate the influence of the change in the outside temperature on the inside temperature and detect the temperature abnormality extremely accurately.

[0007]

The first aspect of the present invention is shown in FIG.
As shown in (A), a plurality of temperature sensors 1A, 1B to 1 distributed and installed in a plurality of parts in the engine room.
X and the temperature sensors 1A, 1B to 1X in the normal state
The temperature gradients between the installed parts are stored as the reference gradients, the reference gradients in the memory 2 and the measured temperature gradients actually measured by the temperature sensors 1A, 1B to 1X. And a temperature abnormality determination means 4 for determining a temperature abnormality in the engine room based on the output of the comparison means 3 and issuing at least a warning.

According to the second aspect of the present invention, the inside temperature sensor 5 for detecting the temperature inside the engine room, the outside temperature sensor 6 for detecting the outside temperature, and the inside and outside temperatures based on the signals from the inside and outside temperature sensors 5, 6. There is provided a difference calculating means 7 for obtaining a measured difference between the above and a temperature abnormality judging means 9 for judging a temperature abnormality in the engine room based on a value indicated by the difference calculating means 7 and at least issuing a warning.

The temperature gradient of the first invention means, for example, a temperature difference (absolute value) between one temperature sensor serving as a reference and another temperature sensor. Further, the number of temperature sensors may be two, and in this case, the deviation between one actually measured temperature gradient and the corresponding reference gradient is compared with the threshold value. In a preferred aspect of the second invention, a plurality of inside air temperature sensors 5 are provided, and the maximum value or average value thereof can be set as the engine room internal temperature.

[0010]

When a fire occurs in the engine room, the temperature near the ignition source becomes higher than other parts. Therefore, the actually measured temperature gradient of one of the plurality of temperature sensors distributed in the engine room, which serves as a reference, and the other temperature sensor corresponding thereto changes due to the occurrence of a fire.

Therefore, according to the first aspect of the present invention, the deviation between the reference gradient in the normal state and the actually measured temperature gradient is obtained by the comparison means, and the output of the comparison means is set to a threshold value determined assuming a predetermined temperature abnormality. By determining whether or not the temperature is too large by the temperature abnormality determining means, it is possible to accurately detect the temperature abnormality in the engine room, which does not include the threshold value corresponding to the measured temperature.

According to the second aspect of the invention, the actual difference between the inside temperature and the outside temperature of the engine room is compared with the threshold value 8 of the inside / outside air temperature difference determined by assuming the temperature abnormality, and the change of the outside temperature is detected. The temperature anomaly in the engine room is corrected by correcting the temperature.

[0013]

As described above, according to the present invention, since the threshold value relating to the measured temperature gradient or the temperature difference between the inside air and the outside air in each part in the engine room is to be determined, the threshold value corresponding to the measured temperature is set. It is possible to accurately detect the temperature abnormality by avoiding the malfunction caused by the fluctuation of the outside temperature when the target temperature is determined.

[0014]

The present invention will be described in detail below with reference to the drawings. FIG. 2 is a block diagram showing an embodiment of a vehicle temperature abnormality detection device according to the present invention. In FIG. 2, reference numerals 11 to 1
Reference numeral 5 is a temperature sensor for detecting a fire installed in the engine room, and for example, a winding resistor, a thermistor or the like is used. The outputs of the temperature sensors 11 to 15 are detected in a time division manner, and are input to the electronic control unit 17 having a microcomputer via the A / D converter 16. The electronic control unit 17 selects, for example, one reference temperature sensor (here, the temperature sensor 11), detects the temperature Tt1 indicated by the temperature sensor 11 and the other temperature sensors 12 to 12.
Each measured difference T from the detected temperature Tt2 to Tt5 indicated by 15
T1-Tt2, ..., Tt1-Tt5 (hereinafter referred to as actually measured temperature gradients) are calculated, and the obtained four actually measured temperature gradients (absolute values) are set in a register.

Here, as shown in FIG. 3, for example, each of the temperature sensors 11 to 15 is attached to each of the four corners and the center of the back surface 10 of the top panel forming the engine room.
In this case, the temperature sensor 11 serving as a reference may be any of the above-mentioned arranged portions, but here, the temperature sensor 11 is arranged at the center and the temperature sensors 12 to 15 are arranged at the four corners.

The electronic control unit 17 is bus-connected to a memory 18 in which reference gradients DIF1 to DIF4 for comparison with the actually measured temperature gradients Tt1 to Tt2, ..., Tt1 to Tt5 are written in advance. In this case, each of the reference gradients DIF1 to DIF4 is, as shown in FIG. 4, a temperature gradient between a portion in which the temperature sensor 11 is normally installed and a portion in which the other temperature sensors 12 to 15 are installed. .

In the electronic control unit 17, the absolute value (hereinafter referred to as deviation) of the corresponding difference between the measured temperature gradients Tt1-Tt2, ..., Tt1-Tt5 and the reference gradients DIF1 to DIF4 in the memory 18 is provided. Comparing means 3 for outputting
(See FIG. 1A) and the deviation output from the comparison means 3, and a temperature abnormality determination means for determining a temperature abnormality when the sum result is larger than a threshold value of a digital amount determined assuming temperature abnormality. 4 (see FIG. 1A).

Further, to the electronic control unit 17, a fire extinguisher drive circuit 19, an alarm lamp 20, an alarm buzzer 21 and a message display memory 22 are connected. The fire extinguisher driving circuit 19 operates when the judgment output from the temperature abnormality detecting means 4 indicates a temperature abnormality, and emits an electric signal for operating the fire extinguisher starting actuator 23. The fire extinguisher starting actuator 23 can use, for example, a motor, and the operation lever of the fire extinguisher 24 can be automatically operated by means such as a wire. Fire extinguisher 24
Is installed in the vehicle compartment or the trunk room, and the nozzle 25 extends in the engine room. Further, the fire extinguisher drive circuit 19 is adapted to send a fuel cut request signal to an electronic fuel injection control ECU (not shown) based on the judgment output from the electronic control unit 17.

The alarm lamp 20, the alarm buzzer 21, and the message display memory 22 are driven by the output from the temperature abnormality detecting means. In addition, the electronic control unit 17 uses the ACC of the ignition switch 26.
In the position, the voltage is supplied from the battery 27, and the fire extinguisher drive circuit 19 is ASL of the ignition switch 26.
(AlwaysSupply Line)
The voltage is constantly supplied from the battery 27.

Next, the operation of the vehicle temperature abnormality detecting device having the above structure will be described with reference to the flow chart shown in FIG. When the engine is started by the ignition switch 26, the battery voltage is supplied to the electronic control unit 17 and the fire extinguisher drive circuit 19, and the flowchart of FIG. 5 starts.

In step S1, the electronic control unit 17
Are detected temperatures Tt1 to Tt from the temperature sensors 11 to 15, respectively.
t5 is set in a predetermined register via the A / D converter 16. Then, in the next step S2, the actually measured temperature gradients Tt1 to Tt2, ..., Tt1 to Tt5 between the detected temperature Tt1 and the detected temperatures Tt2 to Tt5 are calculated.

Actual temperature gradient Tt obtained by the above calculation
1-Tt2, ..., Tt1-Tt5 are deviations VTn = DIF from the corresponding reference gradients DIF1 ... DIF4 in the memory 18 by step S3 corresponding to the comparison means 3 of the present invention.
n-Tn is calculated. Here, Tn = Tt1-Tt
2, ..., Tt1 to Tt5, and n is an integer of 1 to 4.

Subsequently, the electronic control unit 17 executes steps S4 and S5 corresponding to the temperature abnormality detecting means 4 of the present invention, calculates the sum of the deviations VTn calculated in step S3, and sums the results. The deviation is VT. This digital quantity VT is compared with the threshold value of the digital quantity [100] in step S5. The digital amount [100] is a value that is larger than the total temperature of the average deviations calculated between the parts under normal conditions by a predetermined value or more, assuming that the digital amount 1 is a temperature difference of 1 °, and is larger than the allowable limit assuming an abnormal temperature. Set.

Therefore, in the judgment of step S5, VT> 1
In the case of 00, each measured temperature gradient Tn is abnormally large, or some of them are abnormally large. Therefore, it is determined that a fire has occurred in the engine room, and a warning is given in step S6. This emits a signal for driving the alarm lamp 20 and the alarm buzzer 21, and the message display memory 22.
The message written in is displayed on a display panel mounted on the instrument panel, for example.

In the present embodiment, at the same time as the warning, the fire extinguisher drive circuit 19 is activated and the fire extinguisher starting actuator 23 is operated to inject the fire extinguishing agent into the engine room from the nozzle 25 of the fire extinguisher 24 to cause a fire. The fire can be extinguished in the early stages of. Further, in the determination of step S5, VT ≦
In the case of 100, it is determined that each actually measured temperature gradient Tn is within the normal range, and the warning is not issued, and step S7 [warning stop] is processed and the same detection routine is performed again.

As described above, according to the temperature abnormality detecting device of the present embodiment, the temperature sensors 11 arranged in the engine room are not used as the judgment object for the threshold temperature corresponding to the internal temperature.
To 15 actually measured temperature gradients and their respective temperature sensors 11
Since the threshold value relating to the deviation from each reference gradient in the normal state of each portion in which ~ 15 are arranged is the determination target, accurate detection can be performed without being affected by the outside air temperature.

In the above embodiment, step S
As shown in FIG. 4, the total VT of the deviations between the actually measured temperature gradients and the reference gradients in the normal state is compared with the allowable limit digital amount [100] assuming the temperature abnormality related to the total. However, as another example of a more accurate detection method, as a more accurate detection method, as compared with a digital amount that assumes a temperature abnormality for each difference between each measured temperature gradient and each reference gradient, at least one of them is the digital value. It may be determined that the temperature is abnormal when the amount is larger than the amount. The digital amount as the threshold value in this case is a value that represents a predetermined multiple of the average deviation calculated in the normal state. This is because, when the temperature gradient is judged for each deviation, the threshold value is raised instead of summing the deviations to eliminate erroneous judgment as much as possible.

Further, as a modification of the above-mentioned other embodiment, it is also possible to selectively detect the portion for which the deviation is maximum and to judge by the deviation only for this portion. Furthermore, two temperature sensors may be used,
The threshold value in this case also uses the digital amount set to a predetermined multiple of the average deviation in the normal state as described above. Next, a second embodiment of the present invention will be described with reference to FIG.

The second embodiment differs from the above-described embodiment shown in FIG. 2 in that it has an outside air temperature sensor 35 in addition to a plurality of inside air temperature sensors 31 to 34 for detecting the temperature in the engine room. These are the processing function of the control unit 37 and the contents written in the memory 38. Inside air temperature sensor 31-34
Is arranged at a predetermined position on the back surface 10 of the top panel shown in FIG. 3, and the outside air temperature sensor 35 is installed inside the front bumper, for example.

As shown in FIG. 1B, the electronic control unit 37 has a processing function of a difference calculating means 7 for obtaining a difference between the inside air temperature and the outside air temperature according to signals from the inside air temperature outside sensors 31 to 35.
It has a processing function of the temperature abnormality determining means 9 for determining the temperature abnormality when the output value obtained by this processing function is larger than the threshold value of the temperature difference between the inside air and the outside air assuming the temperature abnormality. However, in the second embodiment, the electronic control unit 37 determines the four inside temperature sensors 3 when determining the inside temperature.
Among the detected temperatures Tt1 to Tt4 of 1 to 34, the processing function of the maximum value logic means for making the maximum value the internal temperature is included.

The memory 38 is written with threshold value data set to be higher than the average temperature difference between the normal temperature and the normal temperature by a predetermined temperature. The structure of the fire extinguisher drive circuit 19, the alarm lamp 20, the alarm buzzer 21, the message display memory 22 and the like is similar to that of the embodiment of FIG. The operation of the second embodiment is shown in the flowchart of FIG. That is, by starting the temperature abnormality detection routine, first, in step S11, the electronic control unit 37 fetches the detected temperature Ot of the outside air temperature sensor 35 into the predetermined register via the A / D converter 16. In the following step S12, the inside air temperature sensors 11 to 1
The detected temperatures Tt1 to Tt4 of No. 4 are fetched.

Next, of the detected inside temperatures Tt1 to Tt4 obtained in step S12, the maximum value is detected in step S1.
Logically selected by 3. The internal temperature determined in this way is Tt. The determined inside temperature Tt is the difference calculation means 7
In the next step S14 in which the processing of step S14 is performed, the subtraction processing of Tt-Ot is performed, and the difference Kt from the outside air temperature Ot detected by the outside air temperature sensor 15 obtained in step S11 is calculated.

The actually measured difference Kt between the inside temperature and the outside temperature calculated in step S14 is compared with the threshold value in the memory 38 in step S15 in which the temperature abnormality determining means 9 performs the process. Here, the threshold value is set to 130 °. Therefore, if Kt> 130 ° in the determination in step S5, it is determined that the temperature is abnormal and a warning is issued in step S16, and a signal for driving the alarm lamp 20 and the alarm buzzer 21 is issued, and the message display memory 22 is displayed. The written message is displayed and the fire extinguisher 24
The fire can be extinguished by automatically operating.

Further, in the judgment of step S15, Kt <1
In the case of 30 °, it is determined that each actual measurement difference Kt is within the normal range, and the same detection routine is performed again through step S17 without issuing a warning. As described above, according to the second embodiment as well, since the threshold value to be determined is a value related to the temperature difference between the inside air and the outside air, accurate detection can be performed without being affected by the outside air temperature.

In the second embodiment, the actual measured difference K between the inside air temperature sensors 31 to 34 and the outside air temperature sensor 35.
It is also possible to calculate t and compare the measured value Kt with the threshold value in the memory 38. In this case, the threshold value is a value obtained by multiplying the average temperature difference between the inside temperature sensors 31 to 34 and the outside air temperature in a normal state by a predetermined value. This is also because the maximum temperature difference is not detected, but accuracy is ensured for each part.

[Brief description of drawings]

FIG. 1A is a basic configuration diagram showing a first invention relating to a vehicle temperature abnormality detection device of the present invention, and FIG. 1B is a basic configuration diagram showing a second invention of the device.

FIG. 2 is a specific configuration diagram showing an embodiment of the first invention.

FIG. 3 is an explanatory diagram showing an example of an arrangement mode of a plurality of temperature sensors used in the embodiment of the first invention.

FIG. 4 is an explanatory diagram showing a concept of a reference gradient used in the present invention.

FIG. 5 is a flowchart showing an operation of the embodiment of the first invention.

FIG. 6 is a specific configuration diagram showing an embodiment of the second invention.

FIG. 7 is a flowchart showing an operation of the embodiment of the second invention.

[Explanation of symbols]

1A to 1X ... Temperature sensor, 2 ... Memory, 3 ... Comparison means,
4 ... Temperature abnormality detecting means. 5 ... Inside temperature sensor, 6 ... Outside temperature sensor, 7 ... Difference calculating means, 8 ... Threshold value, 9 ... Temperature abnormality judging means. 11 to 15 ... Temperature sensor, 17 ... Electronic control unit, 18 ... Memory, 20 ... Warning lamp, 21 ... Warning buzzer. 31-34 ... Inside air temperature sensor, 35 ... Outside air temperature sensor, 37 ... Electronic control unit, 38 ... Memory.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Satoshi Fujimoto, 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Co., Ltd. (72) Inventor, Masahiro Miyaji, 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Co., Ltd.

Claims (2)

[Claims] 1. A plurality of temperature sensors respectively dispersedly installed in a plurality of parts in an engine room, and a memory storing a temperature gradient between respective parts where the temperature sensors are normally installed as respective reference gradients. Comparison means for outputting a deviation between each reference gradient in the memory and each actually measured temperature gradient due to the actually measured temperature detected by each temperature sensor, and a temperature abnormality in the engine room is judged based on the output of the comparison means. A temperature abnormality detecting device for a vehicle, further comprising: a temperature abnormality determining unit that issues at least a warning. 2. An inside air temperature sensor for detecting the temperature in the engine room, an outside air temperature sensor for detecting the outside air temperature, and a difference calculating means for obtaining a measured difference between the inside air temperature and the outside air temperature from a signal from the inside and outside air temperature sensor. And a temperature abnormality determining means for determining a temperature abnormality in the engine room based on a value indicated by the difference calculating means and at least issuing a warning.