JP2600379Y2 - Automotive engine room ventilation system - Google Patents

Description

The present invention relates to a vehicle engine room ventilation system.

2. Description of the Related Art When the engine is running, the temperature in the engine room is ventilated by running wind or a radiator fan and does not rise so much. However, after the engine stops, the temperature rises due to residual heat of the engine because the ventilation stops and is installed in the engine room. In some cases, the temperature of the electronic component storage box rises, shortening the life of the internal electronic components. In order to solve such a problem, the thermoelectric generator that generates power by the residual heat of the engine drives the ventilation fan that ventilates the chilled parts in the engine room. A device that suppresses a temperature rise and effectively protects electronic components has already been developed and disclosed in Japanese Patent Application Laid-Open No. Sho 59-108818.

Problems to be Solved by the Invention In order to prevent the temperature in the engine room from rising due to residual heat of the engine when the engine is stopped, instead of providing the thermoelectric generator as described above, a timer is provided and a radiator fan or a radiator fan for a set time after the engine is stopped. A method of rotating a dedicated ventilation fan can be considered, but if the above set time is set to a large value with an emphasis on measures to increase the temperature in the engine room, the remaining capacity of the battery is likely to decrease, and the subsequent startup of the engine is difficult. It has a problem that it tends to be difficult. This problem is remarkable in the case of a battery whose performance has deteriorated after several years.

The present invention seeks to address such issues.

Means for Solving the Problems The present invention is provided with a ventilation fan for ventilating the air in an engine room, and a thermosensitive element such as a thermistor for sensing the temperature in the engine room, and an engine detected by the thermosensitive element. An engine room of an automobile equipped with a control unit including a temperature monitoring circuit that outputs a temperature signal when the temperature in the room becomes equal to or higher than a set temperature, and a driving unit that drives the ventilation fan based on the temperature signal of the temperature monitoring circuit. In the ventilator, a timer circuit for issuing an operation continuation signal for activating the control unit until a set time elapses after the ignition switch is turned off, and a terminal voltage of a battery, which is a vehicle-mounted power supply, activated by the operation continuation signal of the timer circuit. When the voltage drops below the set voltage, the operation of the control unit is stopped. A power supply voltage monitoring circuit for generating an operation stop signal to be operated, and further stores an operation stop signal issued from the power supply voltage monitoring circuit, and a battery deterioration alarm when the ignition switch is turned on based on the stored operation stop signal. An alarm circuit for activating the means is provided.

According to the above, when the ignition switch is turned off and the engine is stopped, the temperature rise in the engine room due to the residual heat of the engine can be prevented, and the power supply (battery) during the ventilation fan operation after the ignition switch is turned off can be prevented. The terminal voltage is monitored and the ventilation fan is stopped before overdischarge to prevent the engine from restarting poorly due to the rising of the battery. Also, the power supply when the timer is running and the ventilation fan is activated and an electric load is applied When the ignition switch is turned on, a warning lamp is lit to notify the occupant that the performance of the power supply (battery) is degraded by storing that the terminal voltage of the battery has fallen below the set voltage. it can.

Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings.

1 is a power supply (battery), 2 is an ignition switch,
Reference numeral 3 denotes a heat-sensitive element such as a thermistor that changes the resistance value by sensing the temperature in an engine room (not shown). Reference numeral 4 denotes a ventilation fan provided in the engine room to ventilate the air in the engine room. Reference numeral 5 denotes the heat-sensitive element. The control unit 5 controls the operation of the ventilation fan 4 in accordance with the resistance value of the ignition switch 3. The control unit 5 controls a timer when the ignition switch 2 is turned on and until a set time (for example, 15 minutes) elapses after the ignition switch 2 is turned off. A timer circuit 51 which operates and outputs a signal power supply voltage; constant voltage circuits 52 and 53 interposed in a signal input system and a power supply system for the timer circuit 51;
When the temperature in the engine room sensed by the thermosensitive element 3 operated by the signal power supply voltage output from the timer circuit 51 exceeds the set temperature upper limit (for example, 60 ° C.), the temperature is set lower than the set temperature upper limit. A temperature monitoring circuit 54 that continuously emits a temperature signal until the temperature falls below the set temperature lower limit value (for example, 55 ° C.), a driving circuit 55 driven by the temperature signal of the temperature monitoring circuit 54, and a driving current of the driving circuit 55 And the timer circuit 51 for operating the ventilation fan 4 by the
The power supply 1 is activated by the signal power supply voltage output from the
A power supply voltage monitoring circuit 57 for monitoring the terminal voltage of the timer circuit 51 and generating a voltage signal serving as a timer operation stop signal when the terminal voltage becomes equal to or lower than a set voltage (for example, 12 volts) to stop the timer circuit of the timer circuit 51; A voltage signal from the power supply voltage monitoring circuit 57, that is, a timer operation stop signal, is stored, and when the ignition switch 2 is turned on, a warning means such as a warning lamp 6 is activated to notify that the power supply (battery) has deteriorated. It is configured.

Hereinafter, the main components of the control unit 5 will be described in detail.

That is, the timer circuit 51 starts the timer operation when the potential becomes high, and interrupts the timer operation when the low potential is applied during the operation of the timer. And a first transistor which is turned on when the ignition switch 2 is turned on.
A second transistor 51c which is turned on when the first transistor 51b is turned on and which is turned on when the ignition switch is turned off when the timer is turned off, and which continues to be turned on by the low potential of the control terminal of the timer IC 51a; The third transistor 51d that is turned on when the second IC is turned off and gives a high potential to the trigger terminal of the timer IC 51a, the timing resistor 51e and the timing capacitor 51f that set the timer operation time, and the transistors 51b, 51c, and 51d. And a plurality of associated resistors.

The temperature monitoring circuit 54 that monitors the temperature in the engine room
An operational amplifier 54a having a differential input terminal, a resistor 54b constituting a voltage divider for setting the set temperature upper limit together with the thermosensitive element 3 such as a thermistor, and a set temperature upper limit (for example, 60
° C) and a set temperature lower limit value (for example, 55 ° C), that is, resistors 54c and 54d for setting a width of hysteresis (for example, 5 ° C);
It comprises a plurality of resistors and capacitors associated with the operational amplifier 54a, and the temperature signal output from the output terminal of the operational amplifier 54a is input to the input terminal of the drive circuit 55 via the resistor.

A power supply voltage monitoring circuit 57 for monitoring the terminal voltage of the power supply (battery) 1 includes an operational amplifier 57a having a differential input terminal,
Zener diode 57 for setting a set voltage (for example, 12 volts) indicating that power supply (battery) 1 is in an overdischarged state
b, and a plurality of resistors and capacitors associated with the operational amplifier 57a. A voltage signal generated from the output terminal of the operational amplifier 57a when the terminal voltage of the power supply (battery) 1 falls below a set voltage. That is, the timer operation stop signal is input to the trigger terminal of the timer IC 51a constituting the timer circuit 51.

An alarm circuit 58 that stores a voltage signal generated from the operational amplifier 57a of the power supply voltage monitoring circuit 57, that is, a timer operation stop signal, and notifies an occupant that the power supply (battery) 1 has deteriorated.
The power supply terminal B is connected to the power supply (battery) 1 and the input terminal S is connected to the operational amplifier constituting the power supply voltage monitoring circuit 57.
A storage element 58a such as a flip-flop element connected to the output terminal of 57a and a base terminal connected to the storage element 58a
And a transistor 58b connected to the other end of the warning lamp 6, one end of which is connected to the load side terminal of the ignition switch 2 at one end.

Next, the control unit 5 configured as described above
The operation of will be described. That is, when the ignition switch 2 is turned on, the first transistor 51b is turned on, and the first transistor 51b is turned on.
When the transistor 51b is turned on, the second transistor 51c is also turned on, and the signal power supply voltage is supplied to the temperature monitoring circuit 54 and the power supply voltage monitoring circuit 57 when the second transistor 51c is turned on. The temperature monitoring circuit 54 to which the power supply voltage for the signal is applied receives a ventilation signal via the drive circuit 55 and the relay 56 based on a temperature signal generated when the temperature in the engine room sensed by the thermosensitive element 3 becomes equal to or higher than the set temperature upper limit value. 4
To operate the ventilation fan 4 to stop the operation of the ventilation fan 4 when the temperature in the engine room falls below the set temperature lower limit value by the operation of the ventilation fan 4, thereby performing a normal operation of adjusting the temperature in the engine room.

Similarly to the temperature monitoring circuit 54, the power supply voltage monitoring circuit 57 to which the signal power supply voltage is applied monitors the terminal voltage of the power supply (battery) 1. In this case, the engine is rotated by turning on the ignition switch 2. Since the charging is being performed by the charging generator, the terminal voltage of the power supply (battery) 1 does not fall below the set voltage, so that the low voltage is applied to the output terminal of the operational amplifier 57a constituting the power supply voltage monitoring circuit 57. The voltage signal of the potential, that is, the timer operation stop signal is not issued.

Next, when the ignition switch 2 is turned off, the first transistor 51b of the timer circuit 51 is turned off and the second transistor 51c is also turned off, but the third transistor 51d which is turned on when the ignition switch 2 is turned off. When the high potential is applied to the trigger terminal, the timer operation of the timer IC 51a starts. When the timer operates, the second transistor 5c is kept on by the low potential of the control terminal which becomes the low potential. Will not be interrupted.

As described above, during the timer operation of the timer IC 51a started by the turning-off operation of the ignition switch 2, the signal power supply voltage which becomes the operation continuation signal by the turning-on operation of the second transistor 51c is similar to the turning-on operation of the ignition switch 2. The given temperature monitoring circuit 54 for the temperature in the engine room performs the on / off operation of the ventilation fan 4 as shown in the flowchart of FIG. 2 in accordance with the temperature in the engine room in the same manner as when the ignition switch 2 is turned on.

A power supply voltage monitoring circuit 57 to which a signal power supply voltage serving as an operation continuation signal is given by an ON operation of the second transistor 51c during a timer operation started by an OFF operation of the ignition switch 2 similarly to the temperature monitoring circuit 54 described above.
Monitors the terminal voltage of the power supply (battery) 1 when the ignition switch 2 is turned off, that is, when the power supply (battery) 1 of the charging generator is not charged because the engine does not rotate. If the performance of the battery (battery) has not deteriorated, the terminal voltage of the power supply (battery) 1 will not exceed the terminal voltage even if the temperature in the engine room is equal to or higher than the set temperature upper limit value and the ventilation fan 4 continues to rotate during the set time of the timer. As shown by the solid line in FIG. 3, the voltage does not fall below the set voltage (for example, 12 volts), but when several years have passed after the purchase and the performance of the power supply (battery) 1 has deteriorated, 1 in FIG.
As indicated by the dashed line, the terminal voltage of the power supply (battery) 1 may be lower than the set voltage. In this case, a low potential voltage signal, that is, a timer operation stop signal is issued from the output terminal of the operational amplifier 57a of the power supply voltage monitoring circuit 57, and the trigger terminal of the timer IC 51a constituting the timer circuit 51 connected to the output terminal. Becomes low potential, and the timer operation of the timer IC 51a stops. The control terminal which has been at the low potential becomes high potential by stopping the timer operation, so that the second transistor 51c is turned off, the signal power supply voltage supplied to the temperature monitoring circuit 54 is stopped, and the operation of the temperature monitoring circuit 54 is stopped. I do. Therefore, the ventilation fan 4 driven via the drive circuit 55 and the relay 56 by the temperature signal of the temperature monitoring circuit 54 is turned off.

As described above, when the ventilation fan 4 is operated after the ignition switch 2 is turned off to prevent the temperature in the engine room from rising due to the residual heat of the engine, it is determined that the terminal voltage of the power supply (battery) 1 is lower than the set voltage. When a voltage signal (timer operation stop signal) is issued from the detected output terminal of the power supply voltage monitoring circuit 57, the output terminal Q of the storage element 58a of the alarm circuit 58 in which the voltage signal is input to the input terminal S has a high potential. The high potential of the output terminal Q of the storage element 58a is stored and stored unless the connection to the power supply (battery) 1 is disconnected. Therefore, when the ignition switch 2 is turned on next time, the circuit from the power supply (battery) 1 to the ground point via the ignition switch 2, the warning lamp 6, and the transistor 58b turned on by the high potential of the output terminal Q of the storage element 58a. Is closed and warning lamp 6
Lights up to notify the occupant that the power supply (battery) 1 is deteriorated.

The warning lamp 6 lit by the alarm circuit 58
Instead, a charge lamp may be used, one terminal of which is connected to the load side terminal of the ignition switch 2 and the other terminal of which is grounded via a charge lamp relay of a charging generator (not shown). .

Effects of the Invention As described above, according to the present invention, a ventilation fan for ventilating the air in the engine room, and a thermosensitive element such as a thermistor for sensing the temperature in the engine room are provided, and the thermosensitive element senses the temperature. A vehicle equipped with a control unit comprising: a temperature monitoring circuit that outputs a temperature signal when the temperature in the engine room becomes equal to or higher than a set temperature; and a driving unit that drives the ventilation fan based on the temperature signal of the temperature monitoring circuit. In the engine room ventilation system,
A timer circuit that issues an operation continuation signal for activating the control unit until the set time has elapsed since the ignition switch was turned off, and a terminal voltage of a battery that is a vehicle-mounted power supply that is activated by the operation continuation signal of the timer circuit and is equal to or lower than the set voltage. A power supply voltage monitoring circuit for issuing an operation stop signal for stopping the operation of the control unit, storing an operation stop signal issued from the power supply voltage monitoring circuit, and an ignition switch based on the stored operation stop signal. By providing an alarm circuit that activates the battery deterioration alarm means when turned on, the terminal voltage of the power supply (vehicle-mounted battery) is monitored during the operation of the ventilation fan after the ignition switch is turned off to prevent overdischarge. Stop the ventilation fan and restart the engine due to the rising battery. Failure can be prevented, and the state of the battery can be detected more accurately by measuring the terminal voltage of the power supply (battery) when the timer is running and the ventilation fan is running and an electric load is applied. By storing the battery terminal voltage measurement information and activating the battery deterioration warning means when the ignition switch is turned on, a more accurate battery state taking into account not only the battery discharge state but also the degree of fatigue can be obtained. Can be notified to the driver, which has a great effect practically in combination with the simplification of the configuration.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, FIG. 2 is a flowchart showing an operation mode of the present invention, and FIG. 3 is a fluctuation state of terminal voltage of a power supply (battery) during operation of a ventilation fan after the engine is stopped. FIG. DESCRIPTION OF SYMBOLS 1 ... Power supply (battery), 2 ... Ignition switch, 3 ... Thermal element, 4 ... Ventilation fan, 5 ... Control unit, 51 ... Timer circuit, 51a ... Timer I
C, 52, 53 ... constant voltage circuit, 54 ... temperature monitoring circuit, 54a ...
... operational amplifier, 55 ... drive circuit, 56 ... relay, 57 ...
Power supply voltage monitoring circuit, 57a ... operational amplifier, 57b ... Zener diode, 58 ... alarm circuit, 58a ... storage element, 58b ...
... transistor, 6 ... warning lamp.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B60K 11/04

Claims (1)

(57) [Scope of request for utility model registration] A ventilation fan for ventilating air in an engine room, and a thermo-sensitive element such as a thermistor for sensing the temperature in the engine room are provided, and the temperature in the engine room detected by the thermo-sensitive element is set. An ignition switch for an automobile engine room ventilation system equipped with a control unit including a temperature monitoring circuit that outputs a temperature signal when the temperature is equal to or higher than a temperature, and a driving unit that drives the ventilation fan based on the temperature signal of the temperature monitoring circuit. And a timer circuit for issuing an operation continuation signal for activating the control unit until a set time has elapsed since the power supply was turned off. Generates an operation stop signal to stop the operation of the control unit. A power supply voltage monitoring circuit, and an alarm circuit for storing an operation stop signal issued from the power supply voltage monitoring circuit and activating a battery deterioration alarm unit when an ignition switch is turned on based on the stored operation stop signal. An engine room ventilation system for an automobile.