JPH0448927B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an engine room ventilation system that ventilates the inside of the engine room after the engine is stopped.

In recent years, with the progress of A-electronics,
Various electronic components are also installed in the engine room, but the lifespan of these types of electronic components will be shortened if they are exposed to high temperatures.

By the way, when the engine is running, the temperature inside the engine room does not rise much because it is ventilated by the running wind or the radiator fan, but after the engine is stopped, the ventilation stops and the temperature rises due to residual engine heat. The temperature inside the storage box rises further.

For this reason, for example, as shown in Japanese Utility Model Application Publication No. 56-2015, the ventilation fan in the engine room is started by the vehicle battery using a relay contact linked to engine stop, and the ventilation fan is started after a predetermined time set by a timer. What makes it stop is known.

However, although it is possible to prevent a temperature rise by ventilating the cold parts in the engine room after the engine is stopped, there is a problem in that this consumes the vehicle battery and causes the battery to run out.

In addition, this conventional ventilation system uses a timer to set the stop time, which prevents the ventilation fan from stopping earlier than necessary or rotating unnecessarily relative to the operating state before the engine stops. There is a problem with it being stored away.

The present invention has been made in view of the problems of the prior art, and is particularly designed to increase the atmospheric temperature in the engine room due to engine residual heat after the engine is stopped without consuming the on-vehicle battery, and to improve ventilation. The purpose of the present invention is to provide an engine room ventilation system that can optimize the starting and stopping of the fan according to the operating state before stopping the engine.

Therefore, in one configuration of the present invention, there is provided a ventilation fan that ventilates the cooled parts in the engine room, a thermoelectric generator that generates electricity using the residual heat of the engine, and a thermoelectric generator that uses the generated power of the thermoelectric generator to pass the electricity to the ventilation fan. a driving means for driving the ventilation fan; a temperature sensor for detecting the ambient temperature in the engine room; and control means for determining that the ventilation fan has been raised by the ventilation fan, and, based on this determination, for allowing the drive means to supply power from the thermoelectric generator to the ventilation fan.

With this configuration, the thermoelectric generator is used as a power source to drive the ventilation fan, especially when the ambient temperature in the engine compartment rises due to engine residual heat after the engine has stopped. In this case, the control means determines that the atmospheric temperature in the engine room has risen above a predetermined value and controls the drive of the ventilation fan. A ventilation fan can be reliably started and stopped according to the atmospheric temperature in an engine room, and the ventilation fan can be started and stopped optimally depending on the operating state of the engine before stopping. The effect of being able to do this is produced.

Further, in another configuration of the present invention, a ventilation fan that ventilates a cooling section in the engine room, a thermoelectric generator that generates electricity using residual heat of the engine, and a thermoelectric generator that uses the generated power of the thermoelectric generator to pass the electricity to the ventilation fan. a driving means for driving the ventilation fan; a detecting means for detecting that the ignition switch is in the cutoff state; and control means for determining that the engine is in a residual heat state based on the power generation of the thermoelectric generator, and allowing the driving means to supply power from the thermoelectric generator to the ventilation fan based on this determination. It is characterized by the fact that

With this configuration, when the ambient temperature in the engine room rises due to engine residual heat after the engine has stopped, the thermoelectric generator is used as a power source to drive the ventilation fan, so there is no need to consume the vehicle battery Temperature rise can be prevented, and in that case, the control means determines that the engine is in a non-operating state and has residual heat, and controls the drive of the ventilation fan.
The ventilation fan can be reliably started in accordance with the transition from the operating state to the non-operating state of the engine, and furthermore, when the amount of residual heat in the engine decreases, the thermoelectric generator generates electricity so that the engine remains in the residual heat state. In other words, when there is no longer any risk of temperature rise in the engine compartment, the ventilation fan can be reliably and automatically stopped without using circuit components such as a timer. The effect is that the starting and stopping of the engine can be optimized according to the operating state of the engine before the engine is stopped.

The invention will be explained by means of illustrated embodiments.

FIG. 1 shows the engine compartment of a vehicle equipped with the ventilation system of the present invention. An engine 2 is housed in an engine room 1 that projects forward of the vehicle, and a radiator fan 3 is provided on the entire surface of the engine room 1. On the other hand, storage boxes 12a and 12b containing electronic components are arranged in the engine room 1.

During engine operation, the engine room 1 is ventilated by outside air flowing in from the front grill 11 or by the radiator fan 3, and the storage box 1 is ventilated.
The temperature inside 2a, 12b does not rise.

At the bottom of the engine room 1 is a ventilation fan 4a,
4b is installed. The ventilation fan 4a is for intake,
The ventilation fan 4b is for exhaust.

On the other hand, one of the exhaust manifolds 5 branching out to each cylinder of the engine 2 is provided with a thermoelectric generator 6 .

The structure of the thermoelectric generator 6 will be explained below with reference to FIG.

The generator 6 has P-type thermoelectric elements 61a and N-type thermoelectric elements 61b arranged alternately and radially, with an insulating material 62 interposed between them, and is formed into an annular shape as a whole. Then, the adjacent thermoelectric elements 6
The inner diameter ends and outer diameter ends of 1a and 61b are alternately paired and connected by conductive plates 64a and 64b. The generator 6 has an inner cylinder 63 fitted around the outer periphery of the exhaust manifold 5. An insulating material 62 is also arranged between the inner cylinder 63 and the inner conductive plate 64a. Outer diameter side conductive plate 64b
A heat dissipation fin 66 is fixed to the.

The P-type thermoelectric element 61a is positively charged on the high temperature side and negatively charged on the low temperature side. The N-type thermoelectric element 61b is the opposite. In the thermoelectric generator 6 of this embodiment, the side of the inner cylinder 63 that receives the residual heat of the exhaust manifold 5 is the high temperature side. The thermoelectric elements 61a and 61b are electrically connected in series, and the voltage between the electrode plates 67a and 67b provided on the end faces of the thermoelectric elements 61a and 61b, which are the connection ends and located at the lower end of the figure, is between each thermoelectric element. This is the sum of the electromotive forces of 61a and 61b, and the lead wire 6
5 to the outside. Heat dissipation fin 66
serves to promote the temperature difference between both ends of the thermoelectric elements 61a and 61b, and to increase the generated electromotive force.

Figure 3 shows the electrical circuit of the ventilation system.
72 is an ignition switch, 8 is a comparison circuit, and 9 is a switching circuit.

Comparison circuit 8 includes comparator 81 and variable resistor 82
It becomes more. The negative input terminal of the comparator 81 is connected to the ignition switch 72, and the positive input terminal is connected to the output terminal of the variable resistor 82. A power terminal of the variable resistor 82 is connected to the thermoelectric generator 6. Here, the output voltage Va of the variable resistor 82 is set lower than the output voltage of the battery 71.

Switching circuit 9 consists of resistors 91 and 92 and a switching transistor 93. The ventilation fans 4a, 4b are connected to the thermoelectric generator 6 via a transistor 93.

The operation of the ventilation system having the above configuration will be explained below.

Turn off ignition switch 72 and engine 2
Even after the exhaust manifold 5 has been stopped, the exhaust manifold 5 has residual heat, and the thermoelectric generator 6 generates electricity due to the temperature gradient caused by this.

On the other hand, by turning off the ignition switch 72, the input voltage at the negative input terminal of the comparator 81 is
It becomes oV. As a result, the condition that the engine 2 is in the non-operating state and in the residual heat state is established, and the comparator output becomes the "1" level, so the transistor 93 becomes conductive and the ventilation fans 4a and 4b are activated, as shown in FIG. Engine room 1 as shown by the arrow
Warm air inside the engine room is exhausted and outside air is taken in for ventilation, thereby suppressing a rise in temperature inside the electronic component storage boxes 12a and 12b installed in the engine room.

When the residual heat in the exhaust manifold 5 decreases, the power generated by the thermoelectric generator 6 also decreases, and the ventilation fans 4a and 4b stop. By this time, the engine 2 has also cooled down, and the temperature in the engine room 1 will not rise again.

In this way, the engine room ventilation system of this embodiment is equipped with a thermoelectric generator in the exhaust manifold, as well as intake and exhaust fans at the bottom of the engine room. Since each of the above-mentioned fans is driven by a thermoelectric generator 6 that generates electricity from the residual heat of the exhaust manifold, the temperature rise in the electronic component storage box installed in the engine room is suppressed, the electronic components are protected, and battery life is reduced. There is no consumption of Furthermore, since the comparator circuit 8 determines that the engine 2 is in a stopped state and has residual heat, and controls the drive of the ventilation fans 4a, 4b, the activation of the ventilation fans 4a, 4b is controlled by the engine 2. This can be done reliably in accordance with the transition from the operating state to the stopped state, and the amount of residual heat in the engine 2 decreases, and the thermoelectric generator 6 generates electricity.
If there is no residual heat, that is, engine room 1
When there is no longer any risk of temperature rise inside the room, the ventilation fans 4a and 4b can be reliably and automatically stopped without using circuit components such as timers, and the ventilation fans 4a and 4b can be stopped from starting. can be made optimal according to the operating state of the engine 2 before it is stopped.

In the above embodiments, the ventilation fan may be used for either intake or exhaust.

Further, the comparator circuit 8 may of course be composed of transistors.

As shown in FIG. 4, the electric circuit may be one that detects a temperature rise in the engine room and starts the ventilation fan. That is,
In the figure, the voltage Vb at the connection point between the variable resistor 15 and thermistor 14 connected in series is input to the negative input terminal of the comparator 81.

When the engine is running and the temperature in the engine room 1 is not rising, the resistance value of the thermistor 14 is large and the voltage Vb is higher than the voltage Va. In this state, the output of the comparator 81 is at the "0" level, the transistor 93 is non-conductive, and the ventilation fans 4a and 4b are stopped.

When the engine 2 is stopped and the temperature in the engine room 1 rises, the resistance value of the thermistor 14 decreases, the voltage Vb becomes lower than the voltage Va, the transistor 93 becomes conductive, and the ventilation fans 4a, 4b start. As a result, the engine room 1 is ventilated.

FIG. 5 shows a second embodiment of the present invention, in which a duct 1 is installed between the electronic component storage boxes 12a and 12b and the ventilation fan 4.
0 is installed so that outside air is directly supplied to each storage box 12a, 12b.

Even with such a configuration, the same effects as in the first embodiment can be obtained, and the ventilation fan 4 may be small.

Incidentally, the ventilation fan of each of the above embodiments may have a structure as shown in FIG. 6. That is, two perforated plates 41a and 41b are provided at the lower opening facing the road surface of a ventilation fan using an axial flow fan.
The through holes 42 of the perforated plates 41a and 41b are connected to other perforated plates 4.
It is formed to be offset from the through holes 1a and 41b.

As a result, only air is allowed to flow through the perforated plates 41a and 41b (arrows in the figure), and mud, water, pebbles, etc. thrown up by the front wheels are blocked, and the mechanism of the ventilation fan 4 is protected.

The ventilation fan 4 may be provided directly on the electronic component storage box. That is, the storage box 12 for electronic components 13 shown in FIG. 7 is provided with a ventilation fan 4 in a ceiling opening 121 and a through hole 122 in the side surface.
Air is circulated by the ventilation fan 4 as shown by the arrow in the figure, and the storage box 12 is ventilated.

As described above, the ventilation system of the present invention uses a thermoelectric generator that generates electricity from the residual heat of the engine to drive the ventilation fan, thereby suppressing the temperature rise inside the electronic component storage box after the engine is stopped, and effectively operating the electronic components. It protects the engine, does not consume battery power, and allows the ventilation fan to be started and stopped in an optimal manner according to the operating state before the engine is stopped.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an engine room showing a first embodiment of the present invention, Fig. 2 is an overall sectional view of a thermoelectric generator, Figs. 3 and 4 are electrical circuit diagrams, and Fig. 5 is a sectional view of the present invention. FIG. 6 is a sectional view of the ventilation fan, and FIG. 7 is a sectional view of the electronic parts storage box. 1...Engine room, 2...Engine, 4,
4a, 4b...Ventilation fan, 5...Ventilation manifold, 6...Thermoelectric generator, 9...Switching circuit, 12, 12a, 12b...Electronic component storage box,
14...Thermistor (temperature sensor), 72...Ignition switch.

Claims (1)

[Scope of Claims] 1. A ventilation fan that ventilates a cooling section in an engine room; a thermoelectric generator that generates electricity using residual heat of the engine; and a system that supplies the generated power of the thermoelectric generator to the ventilation fan. , a driving means for driving the ventilation fan; a temperature sensor for detecting the atmospheric temperature in the engine room; and, based on the temperature detection by the temperature sensor, the atmospheric temperature in the engine room has increased beyond a predetermined value. 1. An engine room ventilation system, comprising: a control means for determining the power supply of the thermoelectric generator to the ventilation fan by the driving means based on the determination. 2. A ventilation fan that ventilates the cold parts in the engine room; a thermoelectric generator that generates electricity from the residual heat of the engine; and a thermoelectric generator that supplies the generated power of the thermoelectric generator to the ventilation fan to drive the ventilation fan. a detection means for detecting that the ignition switch is in a cut-off state; and a detection means for detecting that the engine is in a non-operating state based on the detection by the detection means, and a drive means for detecting that the engine is in a non-operating state based on the power generation of the thermoelectric generator. and control means for determining whether the engine is in a residual heat state and, based on this determination, allowing the driving means to supply power from the thermoelectric generator to the ventilation fan.