JPH06185362A - Two-phase cooling device for internal combustion engine - Google Patents

Abstract

PURPOSE: To control the start and stop of a fan-unit for blowing air to a heat exchanger for circulating the coolant heated in an engine with a part thereof vaporized in response to the change of the liquid phase volume and vapor phase volume in the coolant. CONSTITUTION: The start and stop of a fan-unit 28 is controlled via a control circuit CMD on the basis of whether the liquid level H1 of liquid phase L detected by a liquid level detector 34 arranged in a liquid coolant circulation system consisting of a heat exchanger 10, a line 4 and a secondary liquid cannula 14 is higher or lower than a reference level H0 . As the controlled is based on the liquid level of liquid phase, it is different from that of the known two-phase cooling system, which is based on coolant temperature, it is possible to control the stop of the engine to prevent the coolant from being spilt over from an expansion tank.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for an internal combustion engine of an automobile or the like, and more particularly to a cooling liquid which has reached a boiling point in the engine and which contains vaporized vapor and which is discharged from the engine.
The present invention relates to a two-phase cooling device for an internal combustion engine, which is condensed into a complete liquid and then sent back to the engine.

[0002]

2. Description of the Related Art In a cooling device of this type, a cooling liquid (usually a liquid in which water and an appropriate antifreezing agent are mixed) has two phases, a liquid phase and a vapor phase, and therefore, generally two phases are used. It operates in a mode called a mode. This two-phase mode cooling method is different from the normal single-phase mode cooling method in which the cooling liquid is a single-phase liquid.

In a normal single-phase mode cooling method, the liquid coolant which has come out of the engine is cooled by a radiator provided with a fan and then returned to the engine. The liquid is circulated by forced convection due to the operation of a pump installed in the cooling circuit.

However, in the cooling circuit operating in the two-phase mode, the vaporized cooling liquid from the engine is provided in the same position as the ordinary cooling radiator in the circuit and operates in the ordinary single-phase system. It is condensed in the heat exchanger.

Known two-phase cooling systems for internal combustion engines are:
A heat exchanger having an inlet pipe for a vapor-phase cooling liquid and an outlet pipe for a cooling liquid condensed and cooled to be in a liquid phase, an expansion tank, and a connecting pipe connecting the heat exchanger to the engine. And a motor drive fan unit for controlling the air volume of the air passing through the heat exchanger, the cooling tank being constituted by the heat exchanger, the expansion tank and the connecting conduit.

In this type of two-phase cooling system, the motor-driven fan unit, like a conventional cooling radiator for single-phase operation, is shown with a temperature detector known as a "hot junction" in the cooling circuit. The temperature is controlled based on the temperature.

The motor-driven fan unit is activated when the temperature of the cooling liquid detected by the temperature detector exceeds a predetermined threshold value, and is stopped when the temperature of the cooling liquid drops below the threshold value.

[0008]

There are several drawbacks to the above arrangement.

First, when the engine is stopped, the temperature of the suction port of the circulation pump in the cooling circuit drops sharply, so that the control means for the motor drive fan unit that responds to the heat contact cannot follow it. , Continue operation for a short time. Therefore, the cooling liquid boils in the engine, and the liquid-phase cooling liquid moves into the expansion tank. Under these conditions, there is a risk of cooling liquid overflowing the expansion tank if the motor-driven fan unit is not properly controlled.

Further, if the heat contact is provided at the coolant delivery port of the engine, it is not possible to provide the heat contact at this location because it is not possible to sufficiently detect the minute fluctuation of the temperature at that location.

The present invention aims to remedy these drawbacks.

[0012]

In order to achieve the above object, the present invention is configured as follows.

A heat exchanger having an inlet pipe for the vapor phase cooling liquid to be condensed, an outlet pipe for the cooling liquid condensed and cooled into a liquid phase, an expansion tank and a heat exchanger for the engine. A two-phase cooling system for an internal combustion engine comprising a cooling circuit having a connecting line and a motor-driven fan unit adapted to control an air volume of an air flow passing through a heat exchanger. A liquid level detector is provided at a position of a predetermined detection level in any one of the heat exchanger, the pipeline, and the expansion tank, which are the respective components of the circuit, and the liquid level detector is provided in each of the components of the cooling circuit. A two-phase cooling device for an internal combustion engine, characterized in that the two-phase cooling device for an internal combustion engine is connected to a control device for starting or stopping a motor-driven fan unit according to a liquid level of a cooling liquid.

The liquid level detector may be provided inside or on the side wall of the liquid jacket of the heat exchanger.

The liquid level detector may be provided inside the delivery pipe line connecting the engine and the inlet pipe of the heat exchanger or in the pipe wall.

The liquid level detector may be provided inside or on the side wall of the expansion tank.

A liquid level detector for controlling the motor-driven fan unit is provided in a heat exchanger or a pipe line forming a cooling circuit, and when the detected liquid level becomes lower than the detection level. The motor-driven fan unit may be activated so that the motor-driven fan unit is controlled to stop when the liquid level becomes higher than the detection level.

A liquid level detector for controlling the motor drive fan unit) is provided in the expansion tank constituting the cooling circuit, and when the detected liquid level becomes higher than the detection level, the motor drive fan unit is controlled.・ Start the unit,
The motor-driven fan unit may be controlled to stop when the liquid level becomes lower than the detection level.

When the liquid level detector is provided in the heat exchanger,
It is desirable that the heat exchanger is provided with a first liquid jacket and a second liquid jacket provided with a cooling liquid inlet pipe and a cooling liquid outlet pipe, and a liquid level detector is provided in the second liquid jacket.

Preferably, the liquid level detector comprises two electrodes, both electrodes being activated when both are out of the liquid phase and when both are immersed in the liquid phase.

The liquid level detector may be a float type detector.

It is desirable that the control device be composed of a power relay provided between the liquid level detector and the motor drive fan unit.

The power relay may be provided separately from the liquid level detector.

The power relay may be integrated into the liquid level detector.

In a device in which the cooling liquid is sent out in a liquid phase from a heat exchanger through an inlet pipe equipped with a pump,
It is desirable to select the detection level of the liquid level detector so that the liquid temperature of the liquid phase sucked into the pump becomes lower than the cavitation temperature at which bubbles are generated in the liquid.

[0026]

[Function] The start / stop of the motor-driven fan unit is controlled according to the liquid level of the cooling liquid in the liquid phase detected by the liquid level detector provided in any of the heat exchanger, the pipeline or the expansion tank. Thereby, the cooling is controlled according to the amounts of the liquid phase and the vapor phase in the cooling liquid. Since the control is not performed by detecting the temperature of the cooling liquid, the risk of the cooling liquid flowing into the expansion tank and overflowing when the engine is stopped is eliminated.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 is a schematic diagram showing the construction of a main part of a cooling circuit for an internal combustion engine which operates in a two-phase mode. The cooling device shown in FIG. 1 cools an internal combustion engine (M) for an automobile, for example. This device recirculates the cooling liquid to the engine (M) and the heat exchanger (10) in a known manner, and the heat exchanger (10) is partially filled with the cooling liquid.

The cooling liquid exits the heat exchanger (10) in the form of a liquid phase (L), passes through the inlet pipe (2) and is fed to the inlet of the engine (M). At least a part of the cooling liquid is vaporized in the engine, and the cooling liquid exits the engine in a state in which the liquid phase (L) and the vapor phase (V) are mixed, and the end of which is connected to the heat exchanger (10). tube
Return to the heat exchanger (10) through (4). In order to circulate the cooling liquid in this direction, the inlet pipe (2) is provided with an expansion tank (6) and a circulation pump (8).

The heat exchanger (10) is provided with a first condensation box or liquid jacket (12) and a second condensation box or liquid jacket (14) on both sides of the body (16) of the heat exchanger. Two fluid sleeves are in communication with each other.

The first liquid sleeve (12) is substantially vertical and has an inlet branch pipe (18) at its upper portion and an outlet branch pipe (20) at its lower portion. The inlet branch pipe (18) is connected to the delivery pipe (4) and receives the cooling liquid from the internal combustion engine (M) in which the liquid phase and the vapor phase are mixed. The outlet branch pipe (20) is connected to the inlet pipe (2) and delivers the liquid-phase cooling liquid to recirculate it to the engine (M). The coolant through the circuit is circulated by the pump (8).

In addition, in order to facilitate understanding, this figure shows the engine (M) and the attached cooling pipes in a simplified manner.

A separation partition wall (22) is provided in the first liquid jacket (12), and an upper chamber (24) where the inlet branch pipe (18) opens and a lower chamber (26) which communicates with the outlet branch pipe (20). , And is divided into two rooms. Second
The vial (14) is also oriented substantially vertically, but without the separating septum.

On the main body (16) of the heat exchanger, a mesh-shaped radiating fin is provided.
It is desirable to provide a horizontal bundle of tubing (also not shown) extending through (not shown) and liquid-tightly connecting the two sets of liquid jackets (12) and (14).

The heat exchanger main body (16) is designed so that an air flow flowing in a direction perpendicular to the paper surface of FIG. The airflow is blown by a motorized fan unit (28) that includes a fan (30) driven by a motor (32).

2 and 3 are schematic views showing a first embodiment of the cooling device of the present invention, which is constructed in substantially the same manner as the device of FIG. In FIGS. 2 and 3, the liquid level detector (34) is provided at a required height position (H ₀ ) in the second liquid cap (14), and the liquid of the cooling liquid in the second liquid cap (14) is provided. The surface is detected. The liquid level in the examples means the depth of the cooling liquid in the liquid sleeve. The cooling liquid is generally water to which an appropriate antifreezing agent is added.

As described above, the cooling liquid is discharged from the engine (M) in a state where the liquid phase and the vapor phase are mixed, passes through the inlet branch pipe (18), and enters the upper chamber (24) of the radiator. enter. Therefore, the upper chamber (24) contains the liquid phase (L) and the vapor phase (V). The mixture of liquid phase and vapor phase is used in the heat exchanger body (16).
Partially passing through the liquid phase (L) and the vapor phase (V) thereabove to reach the second liquid sleeve (14).

FIG. 2 shows the case where the depth (H ₁ ) of the liquid phase (L) is larger than the detection level (H ₀ ). At this time, the liquid-phase cooling liquid passes through the lower part of the heat exchanger body (16) and passes through the first liquid jacket.
Enter the lower chamber (26) of (12) and pump (8) to engine
Reflux to (M).

The liquid level detector (34) is connected to the motor (3) of the motor drive fan unit (28) via the control unit (CMD).
2), the liquid level in the second liquid sleeve (14) is detected by the detector.
Depending on whether it is lower or higher than a predetermined reference level (H ₀ ) provided with (34), the motor (3
It is configured to start and stop 2).

In the case of FIG. 2, since the liquid level (H ₁ ) is higher than the reference level (H ₀ ), the control device (CMD)
Is in a condition to stop the motorized fan unit.

On the other hand, in the case of FIG. 3, the liquid level (H ₂ ) of the liquid phase (L) having the depth (H ₂ ) in the _second liquid sleeve (14) is determined by the liquid level detector (34). Is lower than the reference level (H ₀ ). Under this condition, the controller (CMD) operates to activate the motor driven fan unit (28).

When the motor-driven fan unit (28) is activated, the air volume of the air flow passing through the heat exchanger body (16) increases and the vapor phase (V) of the cooling liquid flowing into the heat exchanger (10) increases. ) Condensation is accelerated. This increases the depth of the liquid phase in the second liquid sleeve (14). This liquid level is the reference level
When it reaches (H ₀ ), the motor drive fan unit (28)
Will stop automatically.

In the embodiment shown in FIGS. 2 and 3, the liquid level detector (34) has two electrodes, which are arranged in the liquid sleeve (14) at a distance, as shown in FIGS. 4 and 5. It has (36). These electrodes (36), when not immersed in the liquid phase,
The motorized fan unit is activated and controlled to stop when immersed.

It goes without saying that instead of the electrode type liquid level detector, another type of liquid level detector such as a float type detector may be applied.

In FIGS. 4 and 5, FIG. 4 shows that the motor drive fan unit (28) is controlled via a power relay (38) provided separately from the liquid level detector (34). It was done.

In FIG. 5, a power relay (not shown) is incorporated in the liquid level detector (34) and operated in the same manner as the relay (38) in FIG.

In the embodiment shown in FIGS. 6 and 7, for example, an electrode type liquid level detector (34) is connected to the engine (M) and the inlet branch pipe (18) of the heat exchanger (10). It is located in the delivery pipe (4). The operation of this device is similar to the embodiment of FIGS. When the liquid level of the liquid phase (L) in the delivery pipe (4) shown in FIG. 7 becomes lower (H ₂ ) than the reference level (H ₀ ), the motor drive fan unit (28) Will start.
The liquid level of the liquid phase (L) shown in FIG. 6 is the reference level (H ₀ ).
When it goes above (H ₁ ) the motorized fan unit stops.

In the other embodiments shown in FIGS. 8 and 9, the liquid level detector (34) also of the electrode type is provided in the expansion tank (6). However, in this embodiment, the motor drive fan unit is controlled in a manner opposite to the above-mentioned embodiments. That is, the expansion tank shown in FIG.
The liquid level of the liquid phase (L) in (6) is the detection reference level.
When (H ₀₎ becomes higher order (H _2), a motor driving Juan
The unit starts up.

When the liquid level of the liquid phase (L) shown in FIG. 8 becomes lower (H ₁ ) than the detection reference level (H ₀ ), the motor drive fan unit stops.

Although the present invention has been described based on the illustrated embodiments, the present invention is not limited to the above-mentioned contents and includes various modified applications.

For example, in the embodiment of FIGS. 2 and 3, the heat exchanger may be provided with one or two liquid sleeves. When two liquid jackets are provided, it is preferable to attach a liquid level detector to each of the liquid jackets, if necessary.

The present invention can be implemented even if the heat exchanger is a multi-pipe type heat exchanger in which one or a plurality of divided partition walls are provided in a liquid sleeve equipped with a liquid level detector. be able to.

The device of the present invention can control the motor drive fan unit with a simple structure.

Therefore, the motor-driven fan unit, the liquid level detector, and the control device connected between the liquid level detector and the motor-driven fan unit can be applied to the existing heat exchanger. is there.

[0054]

【The invention's effect】

(A) When the liquid surface level of the liquid phase in the cooling liquid that is partially vaporized by being heated by the engine (M) is detected by the liquid level detector (34) and the amount of the liquid phase decreases below the reference value. , The fan unit that blows air to the heat exchanger to cool it is started, the vaporized vapor phase is condensed, and when the amount of the liquid phase reaches the reference value, the fan unit is stopped to efficiently cool the engine. can do.

(B) For starting and stopping the fan unit,
Since it is controlled based on the change in the liquid level of the cooling liquid and does not depend on the temperature of the cooling liquid, a large amount of cooling liquid flows into the expansion tank and overflows when the engine is stopped. Can be prevented.

(C) The liquid level detector (34) is connected to the heat exchanger (10),
It can be installed either in the conduit (4) from the internal combustion engine to the heat exchanger or in the expansion tank (6), so it should be installed at an appropriate position depending on the configuration conditions of the engine itself or the vehicle equipped with the engine can do.

(D) When the heat exchanger has two liquid jackets, it is circulated by providing a liquid level detector in the second liquid jacket communicating with the first liquid jacket connected to the cooling circuit. It is possible to prevent an error in liquid level detection due to the turbulent flow of the cooling liquid.

[Brief description of drawings]

1 is a schematic diagram showing the main components of a cooling circuit for an internal combustion engine operating in a two-phase mode.

[FIG. 2] A liquid level detector is provided on one liquid sleeve of a heat exchanger,
FIG. 3 is a schematic view showing the main components of one embodiment of the present invention, showing a state in which the liquid level of the liquid phase stops the motor driving fan unit.

FIG. 3 shows the liquid level of the liquid phase in the embodiment of FIG.
It is the schematic which shows the state which starts a motor drive fan unit.

FIG. 4 is a schematic view showing an embodiment of a control device arranged between a liquid level detector and a motor-driven fan unit.

FIG. 5 is a schematic view showing another embodiment of the same control device as in FIG.

FIG. 6 is a schematic view showing main components of another embodiment of the present invention in which a liquid level detector is provided in a pipe line connecting an engine and an inlet pipe of a heat exchanger. It shows the case where the level is in a state where the motor drive fan unit is stopped.

7 is a graph showing the liquid level of the liquid phase in the embodiment of FIG.
It is a schematic diagram showing the case where it is in the state which starts a motor drive fan unit.

FIG. 8 is a schematic view showing the main components of another embodiment of the present invention in which the expansion tank is provided with a liquid level detector, and the liquid level of the liquid phase is in a state where the motor-driven fan unit is stopped. Indicate the case.

FIG. 9 is a schematic view showing a case where the liquid level of the liquid phase is in a state of activating the motor drive fan unit in the embodiment of FIG. 8;

[Explanation of symbols]

(2) Cooling liquid inlet pipe (4) Cooling liquid feeding pipe (6) Expansion tank (8) Pump (10) Heat exchanger (12) First liquid jacket (14) Second liquid jacket (16) Heat Exchanger body (18) Inlet branch pipe (20) Outlet branch pipe (22) Dividing partition (24) Upper chamber (26) Lower chamber (28) Motor drive fan unit (30) Juan (32) Motor (34) Liquid Surface detector (36) Electrode (38) Power relay (M) Engine (CMD) Controller (L) Liquid phase (V) Steam phase (H ₀ ) Reference level (H ₁ ) (H ₂ ) Liquid level

Claims (13)

[Claims] 1. An inlet pipe for a vapor phase cooling liquid to be condensed.
(18), a heat exchanger (10) provided with an outlet pipe (20) for the cooling liquid which is condensed and cooled to become a liquid phase, an expansion tank (6),
A cooling circuit having pipes (2) and (4) connecting the heat exchanger (10) to the engine (M) is provided, and the air volume of the air flow passing through the heat exchanger (10) can be controlled. In a two-phase cooling device for an internal combustion engine equipped with a motor-driven fan unit (28), a predetermined detection level (H) in any one of the components (10) (4) (6) of the cooling circuit _The liquid level detector (34) is provided at the position ( ₀ ), and the liquid level detector (34) is provided in accordance with the liquid level (H ₂ ) (H ₁ ) of the cooling liquid in each component of the cooling circuit. Control device for starting or stopping the motor drive fan unit (28) (C
MD) connected to a two-phase cooling device for an internal combustion engine. 2. The liquid level detector (34) is used as a liquid jacket for a heat exchanger (10).
The structure is provided inside (14) or on a side wall.
A two-phase cooling device for an internal combustion engine according to claim 1. 3. A liquid level detector (34) is provided inside or on a pipe wall of a delivery pipe line (4) connecting the engine (M) and the inlet pipe (18) of the heat exchanger (10). The two-phase cooling device for an internal combustion engine according to claim 1, wherein 4. The two-phase cooling device for an internal combustion engine according to claim 1, wherein the liquid level detector (34) is provided inside or on a side wall of the expansion tank (6). 5. A liquid level detector (34) for controlling a motor-driven fan unit (28) is a heat exchanger constituting a cooling circuit.
(10) or when the liquid level of the liquid phase (L) in the pipe (4) becomes lower (H ₂ ) than the detection level (H ₀ ), the motor drive fan unit is started, Liquid phase in the component
The liquid level of (L) is higher than the detection level (H ₀ ) (H ₁ )
The two-phase cooling device for an internal combustion engine according to any one of claims 1 to 3, wherein the motor-driven fan unit is controlled so as to be stopped when the above condition occurs. 6. The liquid level detector (34) for controlling the motor-driven fan unit (28) is such that the liquid level in the expansion tank (6) constituting the cooling circuit is higher than the detection level (H ₀ ). When it reaches a high level (H ₂ ), the motor drive fan unit (28) is started and the liquid level of the liquid phase (L) becomes the detection level.
5. The internal combustion engine according to claim 1, wherein the motor-driven fan unit is controlled so as to be stopped when (H ₁ ) which is lower than (H ₀ ) is reached. Two-phase cooling device. 7. A heat exchanger (10) is provided with a first liquid sleeve (12) and a second liquid sleeve (14) provided with a cooling liquid inlet pipe (18) and a cooling liquid outlet pipe (20), and The two-phase cooling device for an internal combustion engine according to claim 2 or 5, wherein the liquid level detector (34) is provided in the second liquid sleeve (14). 8. A liquid level detector (34) comprises two electrodes (36), both electrodes being out of the liquid phase (L) in the constituent element, and both in the liquid phase (L). The two-phase cooling device for an internal combustion engine according to any one of the preceding claims, wherein the two-phase cooling device is activated when immersed in the. 9. The two-phase cooling device for an internal combustion engine according to claim 1, wherein the liquid level detector (34) is a float type detector. 10. A control device (CMD) comprising a liquid level detector (34)
A two-phase cooling device for an internal combustion engine according to any of the preceding claims, characterized in that it comprises a power relay (38) provided between the motor drive fan unit (28). 11. A power relay (38), a liquid level detector (34)
The two-phase cooling device for an internal combustion engine according to claim 10, wherein the two-phase cooling device is provided separately from the above. 12. A power relay (38), a liquid level detector (34)
The two-phase cooling device for an internal combustion engine according to claim 10, wherein the two-phase cooling device is integrated with the above. 13. A heat exchanger (1) using a cooling liquid as a liquid phase (L).
Liquid phase which is adapted to be sent out from the (0) through the inlet pipe (2) having the pump (8) and which is sucked into the pump (8)
The detection level (H ₀ ) of the liquid level detector (34) is selected so that the liquid temperature of (L) is lower than the cavitation temperature at which bubbles are generated in the liquid. A two-phase cooling device for an internal combustion engine according to any one of the preceding items.