JPS6183409A - Multicylinder internal-combustion engine equipped with evaporative cooling apparatus - Google Patents

Abstract

PURPOSE:To improve the detection precision of a liquid-level sensor, temperature sensor, etc. by independently partitioning a cooling jacket except the upper space and preventing the large tilt of the coolant liquid level for the engine tilt. CONSTITUTION:The cooling jacket 2A of a cylinder head 6 is divided into plural parts in the direction of cylinder lines, allowing the upper spaces to communicate, by installing partitioning walls, and also the cooling jacket 2B of a cylinder block 5 is divided into plural parts by the partitioning walls 42 in the direction of cylinder lines. Even if an engine is tilted, the level of coolant liquid does not tilt largely, and erroneous detection on a liquid-level sensor 32, temperature sensor 3, etc. can be prevented. When the partitioning wall of the cylinder block 5 is formed by installing a separate partitioning wall after block casting, the casting of the block 5 is facilitated.

Description

[Detailed Description of the Invention] <Industrial Application Field> This invention involves sealing a predetermined amount of refrigerant in a refrigerant circulation system consisting of a cooling jacket, a condenser, etc., and boiling the stored liquid phase refrigerant within the cooling jacket. The present invention relates to a multi-cylinder internal combustion engine equipped with an evaporative cooling device that cools the internal combustion engine through vaporization, and specifically relates to a cooling jacket structure for the internal combustion engine.

(Prior art) In the well-known water cooling system used in internal combustion engines for automobiles, a considerable temperature difference occurs between the water inlet and water outlet of the cooling jacket, making it difficult to achieve uniform cooling. It is difficult to achieve this, and there is a natural limit to the heat exchange rate in the radiator, so the radiator and cooling fan have to be large.

From this point of view, cooling devices that utilize the latent heat of boiling and vaporization of cooling water have been attracting attention in recent years (for example, the
7608, JP-A-57-62912, etc.). This basically means that the liquid phase refrigerant (
The cooling water is boiled and vaporized, the generated steam is led to an external condenser (radiator), where it is heat-radiated and condensed, and then circulated and supplied into the cooling jacket again. Compared to water-cooled systems that use the simple sensible heat of cooling water, cooling devices that utilize this phase change of refrigerant can utilize latent heat of vaporization, so they can achieve the required amount of heat dissipation by circulating an extremely small amount of cooling water. It has been pointed out that it is satisfactory, and that the capacitor can be made much smaller than a conventional radiator, and that it also has the advantage of making the temperature distribution uniform in each part of the engine.

However, the boiling cooling type cooling device, which is thought to have various advantages as described above, has not actually been put into practical use. That is, those described in the above-mentioned Japanese Patent Publication No. 57-57608, Japanese Patent Application Laid-open No. 57-62912, etc.
The refrigerant circulation system has a non-sealed structure with some parts open to the atmosphere, and the loss of vaporized refrigerant is so large that it cannot be ignored in practical terms.Moreover, air, which is a non-condensable gas, is completely removed from the system. Since it is difficult to do so, there have been problems such as a significant decrease in cooling performance due to residual air.

In view of the above-mentioned circumstances, the present applicant has previously proposed a boiling cooling device in which a predetermined amount of refrigerant is sealed in a closed refrigerant circulation system to perform a boiling and condensing cycle (
(Japanese Patent Application No. 145470/1982, etc.) This is a system in which, for example, at startup, the system is first filled with liquid-phase refrigerant, and then the excess refrigerant is discharged into a reservoir tank while preventing air from entering, thereby sealing a predetermined amount of refrigerant in the closed system. During engine operation, the refrigerant supply pump circulates and supplies liquid phase refrigerant equivalent to the generated steam to the cooling jacket, and the liquid level of the liquid phase refrigerant is always kept above a predetermined level to ensure reliable cooling of the combustion chamber walls, etc. ing.

<Problems to be Solved by the Invention> By the way, in the conventional evaporative cooling device proposed by the present applicant or prior to this, when the internal combustion engine has multiple cylinders and is long in the front and rear of the vehicle, In this case, the liquid level of the refrigerant in the cooling jacket of the internal combustion engine shifts to one side when the engine is mounted. For this reason, a refrigerant liquid level sensor for measuring when the engine is horizontal, which is provided in the cooling jacket, particularly in the cooling jacket portion of the cylinder head, may erroneously detect the refrigerant liquid level. The detection signal of the refrigerant liquid level sensor is important information for maintaining the liquid phase refrigerant level in the cooling jacket at a predetermined value, and the detection signal of the refrigerant temperature sensor is important information for maintaining the liquid phase refrigerant temperature at the target value. It is information. Therefore, the above-mentioned erroneous detection results in a lack of accuracy in controlling the entire system, and there is a possibility that the required control cannot be achieved.

Furthermore, even if the boiling cooling system is not equipped with the above-mentioned liquid level sensor and temperature sensor, if the refrigerant liquid level is uneven as described above, the cylinder on the side where the refrigerant liquid level has relatively decreased will Since the combustion chamber wall is no longer covered by the liquid phase refrigerant, the desired boiling cooling cannot be obtained, and not only is it impossible to control the temperature of the combustion chamber wall, but also dangerous consequences such as seizure due to overheating are likely to occur.

Furthermore, if the steam outlet is provided on the side where the liquid level has risen relatively, there will be many opportunities for the liquid phase refrigerant to flow out of the steam outlet together with the steam and flow into the condenser. In such a state, heat radiation using condensed latent heat cannot be used in the condenser, and the condenser simply exchanges heat with the outside air, which deteriorates the heat radiation effect and makes it difficult to control the refrigerant temperature.

The present invention has been made in order to eliminate the above-mentioned disadvantages, and it is an object of the present invention to provide a refrigerant jacket structure that can prevent the refrigerant liquid level from shifting significantly even if a large multi-cylinder internal combustion engine is tilted due to climbing or the like. purpose.

(Means for solving the problem) To solve this problem, the present invention provides a cooling jacket in the cylinder head in a multi-cylinder internal combustion engine equipped with a boiling cooling device that absorbs heat in a cooling jacket and radiates latent heat of the evaporated vapor phase refrigerant in a condenser. A partition wall is provided inside the cooling jacket section to communicate the upper space facing the steam outlet of the cooling jacket section and to separate and define the lower space into a plurality of sections in the direction of the cylinder row. A partition wall is provided to separate and define a plurality of parts in the cylinder row direction, and the corresponding partitioned cooling jacket parts of the cylinder head and cylinder block are vertically communicated with each other to constitute the cooling jacket, and The partition wall is formed by attaching a separate partition plate to the cast cylinder block.

As a result, even if the internal combustion engine is operated at a large incline, the partition wall of the cylinder head side cooling jacket and the partition wall of the cylinder block side cooling jacket keep the entire cooling jacket independent from each other except for the upper space. Since the refrigerant is separated into a plurality of spaces, only a small deviation of the refrigerant occurs within these spaces. Therefore, there will be no large detection errors in the refrigerant liquid level, the walls of the combustion chamber of a particular cylinder will not be covered with refrigerant and will not be overheated, and furthermore, the liquid phase refrigerant will be less likely to be carried out to the condenser. Become.

Furthermore, it is extremely difficult to integrally cast the partition wall of the cooling jacket on the cylinder block side when casting the cylinder block, which greatly reduces productivity.

Therefore, the partition wall on the cylinder block side was formed as a separate partition wall made of sheet metal or synthetic resin, and after the machining of the cylinder block was completed, this was attached to the cylinder block, and we succeeded in putting it into practical use.

It has already been mentioned that uniform cooling is possible compared to conventional water-cooled systems. These characteristics also appear even when each cylinder has an independent cooling jacket, so
It has a unique configuration that cannot be achieved with a water-cooled type as it must always flow through the walls of the combustion chamber at an appropriate speed.

<Example> Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows the configuration of an embodiment of the present invention, in which an internal combustion engine 1 is filled with a predetermined amount of liquid-phase refrigerant during operation, and is equipped with a cooling jacket 2 for condensing the gas-phase refrigerant with the cooling jacket 2. The condenser 3 and the electric refrigerant supply pump 4 are connected to form a refrigerant circulation closed circuit.

The cooling jacket 2 is formed over both the cylinder block 5 and the cylinder head 6 so as to surround the outer periphery of the cylinder and combustion chamber of the internal combustion engine 1, and the upper part, which is normally a gas phase space, communicates through each cylinder. At the same time, a steam ratio lower is provided at an appropriate position above it. The steam ratio lower communicates with the upper part 3a of the condenser 3 via a connecting pipe 8 and a steam passage 9. The connecting pipe 8 is formed with an upwardly extending discharge pipe mounting part 8a, which is the uppermost part of the refrigerant circulation system, and a cap 10 seals the upper end opening.

The capacitor 3 is an upper tank 11 having the population 3a.
It consists of a core part 12 mainly consisting of fine vertical tubes, and a lower tank 13 that temporarily stores the liquefied refrigerant condensed in this core part 12. The receiver is installed at a position where it can be used, and is further provided with an electric cooling fan 14 for forced cooling on the front or back side thereof.

Further, the lower tank 13 is connected to one end of a refrigerant circulation passage 15 at a relatively lower portion thereof, and one end of a first auxiliary refrigerant passage 16 is connected to an upper portion thereof. The other end of the refrigerant circulation passage 15 is connected to the refrigerant port 2a provided on the cylinder head 6 side of the cooling jacket 2, and includes a three-way type second solenoid valve 17 in the middle part. A refrigerant supply pump 4 is interposed between the refrigerant supply pump 17 and the lower tank 13. Above cooling jacket 2. Condenser 3° Refrigerant supply pump 4. During normal operation, the refrigerant circulation circuit formed by the path of the cooling jacket 2 causes a refrigerant, for example, water with some additives added, to circulate while repeatedly boiling and condensing.

A reservoir tank 21, which is provided outside the closed circulation circuit and serves as an external container for storing a preliminary liquid phase refrigerant, is open to the atmosphere via a cap 22 having an air intake function, and is generally referred to as the cooling jacket 2. installed at the same height position, and the above-mentioned first auxiliary refrigerant passage 16 at the bottom thereof;
A second auxiliary refrigerant passage 23 is connected thereto. and the first
A normally open third solenoid valve 2 is provided in the auxiliary refrigerant passage 16.
4 is interposed. Further, the second auxiliary refrigerant passage 23
is connected to the refrigerant circulation passage 15 via a second solenoid valve 17.

When the second electromagnetic valve 17 is energized, it blocks the refrigerant circulation passage 15 to establish communication between the reservoir tank 21 and the lower tank 13 (flow path A), and when it is not energized, it blocks the second auxiliary refrigerant passage 23. to bring the refrigerant circulation passage 15 into communication (flow passage B).
).

The refrigerant supply pump 4 is one that can pump the liquid phase refrigerant in both forward and reverse directions.If the refrigerant supply pump 4 is driven in the forward direction in the state of the flow path A described above, the refrigerant is pumped from the lower tank 13 to the reservoir tank. The liquid phase refrigerant can be forcibly discharged to the reservoir tank 21, and the liquid phase refrigerant can be forcibly introduced from the reservoir tank 21 to the lower tank 13 by driving in the opposite direction. Furthermore, in the state of flow path B, if the refrigerant supply pump 4 is driven in the forward direction,
Liquid phase refrigerant can be circulated and supplied from the lower tank 13 to the cooling jacket 2.

On the other hand, an air discharge passage 25 for discharging air in the system is connected to the discharge pipe attachment part 8a which is the top of the refrigerant circulation closed circuit described above, and when air is discharged, the air discharge passage 25
In order to recover the liquid phase refrigerant simultaneously overflowing from the air discharge passage 25, the tip of the air discharge passage 25 is opened into the reservoir tank 21. This air discharge passage 25 has a normally closed first t
Ift valve 26 is interposed.

The electromagnetic valves 26, 17, 24, the refrigerant supply pump 4, and the cooling fan 14 are controlled using a so-called microcomputer system. II device 31, specifically, the first liquid level sensor 32 provided in the cooling jacket 2. Control described later is performed based on detection signals from the temperature sensor 33, the second liquid level sensor 34 provided in the lower tank 13, and the negative pressure switch 35 provided at the top of the circulation circuit.

Here, the above-mentioned 1. The second liquid level sensor 32,34 is a float type sensor using a reed switch, for example, and detects whether or not the refrigerant liquid level has reached a set level in an on/off manner. The detection level of the sensor 32 is set at a height approximately in the middle of the cylinder head 6, and the detection level of the second liquid level sensor 34 is set at a height slightly above the opening of the first auxiliary refrigerant passage 16. set in position. Moreover, the temperature sensor 33 is
For example, it is composed of a thermistor, and is provided at a position slightly below the first liquid level sensor 32, that is, at a position normally immersed in the liquid phase refrigerant, to detect the temperature of the refrigerant within the cooling jacket z. In addition, the negative pressure switch 35 uses a diaphragm that responds to the differential pressure between the atmospheric system and the system internal pressure, and regardless of whether it is at high altitude or low altitude, the negative pressure switch 35 responds to the atmospheric pressure under the operating environment.
It detects whether or not there is a negative pressure in the system, and specifically, the operating pressure is set to about -30++ nHg to -50 tm Hg. Note that various sensors for detecting other engine operating conditions, such as an engine rotation sensor and an engine suction negative pressure sensor, are not shown.

On the other hand, the cooling jacket 2 includes a cooling jacket section 2A on the cylinder head 6 side and a cooling jacket section 2B on the cylinder block 5 side. On the cylinder head 6 side, as shown in FIG. 2, a plurality of partition walls 42 of a predetermined height stand up directly above the lower deck between each combustion chamber 41, so that the lower space of the cooling jacket part 2A is divided into plural spaces in the cylinder row direction. It is divided to form a partitioned space, and the upper space is open for communication. The internal combustion engine in this example is a series six
It is a cylinder type engine, and the first liquid level sensor 32 is #1 and #6.
One each is provided at a position above the cylinder at both ends of the partition wall 42 and approximately at the height of the upper end of the partition wall 42 .

In addition, on the cylinder block 5 side, a partition wall 43 shown in FIGS. 4 and 5 is provided in substantially the same plane as the partition wall 42, and the cooling jacket section 2B on the cylinder block side is separated for each cylinder. It is divided into spaces. These independent spaces communicate with the partitioned spaces of the six corresponding cylinder heads via communication passages 44, as shown in FIG. 3.

Therefore, the cooling jacket portions 2A and 2B of the cylinder head 6 and the cylinder block 5 communicate with each other independently for each cylinder (excluding the space above the cylinder head). The refrigerant circulation passage 15 is provided in the jacket portion of each independent cylinder.
The refrigerant population 2a is branched and the liquid phase refrigerant is introduced independently.

In manufacturing the partition walls 42 and 43, the partition wall 42 on the cylinder head 6 side can be cast into the cylinder at the same time as the cylinder 7, but the partition wall 43 on the cylinder block 5 side can be cast in this way from the viewpoint of dividing the casting mold. Simultaneous casting is difficult and productivity is poor. Therefore, as shown in FIG. 4, a pair of notches 5d are provided in the upper deck 5a of the cylinder block 5 and extend from the connecting portion 5c of the cylinder bore wall 5b in a direction perpendicular to the cylinder row direction. The partition wall 43 is constructed by fitting a partition plate made of a separately formed sheet metal base or synthetic resin, for example, with an oval-shaped cross section, through the holes 2 .

Regardless of the above embodiments, the number of partition walls 42, 43 in the cylinder row direction does not matter, and the cylinder head side and the cylinder block side do not necessarily need to be in the same plane. However, it is necessary to take measures to prevent the adjacent jacket spaces from communicating with each other between the corresponding partition walls 42 and 43.

FIG. 6 is a flowchart showing the details of the control executed by the control device 31, which will be explained below along the flow from starting to stopping the engine. In addition, 1st ~
The third solenoid valves 26, 17, and 24 are abbreviated as "Solenoid valve ■", "Solenoid valve ■", etc., and the liquid level inside the cooling jacket 2 is abbreviated as "rC/H internal liquid level". It is.

That is, when the control is started by starting the engine (ignition key-on), after initializing Sl, it is first determined whether the start is an initial start or a restart. Specifically, in S2, it is determined whether the temperature detected by the temperature sensor 33 is higher than a predetermined temperature (for example, 45° C.). Here, if the temperature is below a predetermined temperature, that is, an initial start in a cold state, the process goes through air exhaust control in S3 and then proceeds to warm-up control in S4, and when warm-up is completed, temperature control in step 85 is entered. In this case, in S6, it is determined whether the refrigerant liquid level in the cooling jacket 2 is higher than a set value, and in S7, the second. The third electromagnetic valve 17.24 is switched to control the refrigerant liquid level in the cooling jacket 2 (38). In S9, the refrigerant temperature is determined, and along with the temperature control by cooling fan control performed in S5, SIO, S11. In S12, the liquid level in the capacitor is controlled to increase or decrease.

Next, when it is determined in 313 that the refrigerant temperature is abnormally high and that the cooling system is under positive pressure, high temperature avoidance control is performed in S14. These control loops of 85 to 514 are repeated until the ignition key is turned off. .

On the other hand, if the refrigerant temperature is higher than the predetermined temperature in S2, it is determined that it is time to restart, and in this case, it is unlikely that air will enter the cooling system over time, so the air exhaust control in S3 will be omitted. do.

If a key-off signal is input during this control, an interrupt control routine at key-off is executed. The interrupt control routine will be described later.

An outline of the above control routine will be explained below.

! ■ When the engine is started, the system is normally almost filled with liquid phase refrigerant (for example, a mixture of water and antifreeze), and the reservoir tank 21 is filled with more than enough liquid to completely fill the system. of liquid phase refrigerant is stored. Air discharge control is to discharge air by further filling the system completely with water from this state, and by opening the first solenoid valve 26 and opening the second solenoid valve 1.
7 as flow path A.

The third solenoid valves 24 are controlled to close, and the refrigerant supply pump 4 starts to be driven in the opposite direction.

Thereby, the liquid phase refrigerant in the reservoir tank 21 is introduced into the system via the second auxiliary refrigerant passage 23. This continues for a sufficient period of time to fill the system with water. Therefore, the air remaining in the system is collected in the upper part of the system, and then is forcibly discharged to the reservoir tank 21 outside the system via the air discharge passage 25.

Since the warm-up control capacitor 3 is naturally filled with liquid phase refrigerant, the heat dissipation capacity of the capacitor 3 is suppressed to an extremely low level.
As a result, the temperature of the refrigerant within the cooling jacket 2 rises rapidly, and boiling soon begins.

Warm-up control basically involves waiting while keeping the lower tank 13 and reservoir tank 21 in communication until the refrigerant temperature in the cooling jacket 2 rises to the target temperature.
Therefore, the first solenoid valve 26 is closed, the second solenoid valve 17 is set as the B flow path, and the third solenoid valve 24 is left open. When the actual temperature detected by the temperature sensor 33 reaches the set temperature range, the third solenoid valve 24 is closed to seal the system, and the control is ended.

During warm-up control, the system is open to atmospheric pressure, so
When the set temperature exceeds approximately 100°C, the liquid phase refrigerant in the system is pushed out to the reservoir tank 21 by the generated vapor pressure, and as a result, the liquid level in the cooling jacket 2 or the lower tank 13 increases before the refrigerant temperature reaches the set temperature. The liquid level in the tank drops excessively.

To deal with this, when the liquid level of either one falls below the set level of the first liquid level sensor 32 or the second liquid level sensor 34, the system is immediately sealed and this control is terminated.

After the decoy warm-up control is completed, the refrigerant temperature is controlled. Liquid level control to maintain the liquid level within the capacitor above a set level, and liquid level control within the capacitor to substantially expand or reduce the heat dissipation area when the detected temperature deviates relatively significantly from the target set temperature. Broadly classified.

The set temperature of the liquid phase refrigerant is controlled at 100-110℃ in the partial load region, 80-90℃ in the low-speed high-load region, and 95-100℃ in the high-speed rotation region, depending on the relationship between engine rotation and torque. It is considered appropriate to do so.

This is because in the partial load region, from the standpoint of thermal efficiency, the higher the combustion chamber wall, the better the fuel efficiency.In the low speed and high load region, the temperature inside the combustion chamber is controlled to increase the intake air filling efficiency, which improves the output. This is because it is possible to suppress knocking at the same time as controlling the temperature in the cooling jacket 2. In the high-speed region, it is possible to improve the output by controlling the low temperature in the same way as in the low-speed and high-load region, but the boiling inside the cooling jacket 2 becomes intense. The flow rate of the gas phase refrigerant flowing in the steam passage 9 becomes extremely high, and as a result, the steam boiled in the cooling jacket 2 in the cylinder head 6 tends to be guided to the condenser 3 together with the liquid phase refrigerant. In this case, the liquid phase refrigerant is no longer able to dissipate heat using the latent heat of condensation, and the heat dissipation effect becomes inferior, which limits the miniaturization of condensers. to prevent violent boiling.

(Liquid level reduction control a in the condenser) The liquid phase refrigerant in the condenser 3 is forcibly discharged to the reservoir tank 21 by the refrigerant supply pump 4, the liquid level in the condenser 3 is lowered, and the heat dissipation area of the condenser 3 is expanded. , increasing the heat dissipation ability.The discharge continues until the detected temperature drops to the set temperature.

Finally, seal the inside of the system.

On the other hand, the refrigerant in the condenser 3 is transferred to the reservoir tank 21.
Since the refrigerant continues to boil within the cooling jacket 2 even while being discharged into the cooling jacket 2, its liquid level gradually decreases. If the liquid level on the side of the cooling jacket 2 falls below the set level, control is performed to check for an abnormality in the drop in the refrigerant liquid level in the cooling jacket 2, and if the refrigerant liquid level drops within a predetermined time, the refrigerant supply pump 4 is rotated in the normal direction. Then, the second solenoid valve 17 is set to flow path B and the third solenoid valve 24 is closed to temporarily replenish the liquid phase refrigerant from the condenser 3 to the cooling jacket 2, and the first liquid level sensor 32
maintain at the set level.

In addition, if the refrigerant level decrease exceeds a predetermined time, the refrigerant supply pump 4 replenishes the cooling jacket 2 with liquid phase refrigerant, and in order to prevent the refrigerant level below the condenser from abnormally decreasing, If the internal pressure is positive, the second
The solenoid valve 17 is set to the A flow path, the third solenoid valve 24 is closed, the refrigerant supply pump 4 is reversed, the refrigerant in the reservoir tank 21 is supplied to the lower part of the condenser, and then the refrigerant supply pump 4 is rotated normally again to close the cooling jacket. If the system internal pressure is negative, the difference can be made by simply opening the third solenoid valve 24. While replenishing the refrigerant in the reservoir tank 21 to the lower part of the condenser by pressure, the second solenoid valve 17 is switched to the B flow path, the refrigerant supply pump 4 is rotated forward, and the refrigerant is continuously supplied to the cooling jacket 2. 2. Preventing abnormal refrigerant level drop.

Even if the liquid level in the capacitor 3 is lowered to the maximum level in the liquid level reduction control in the capacitor 3 described above, insufficient heat dissipation capacity cannot be avoided and the liquid level will reach the level set by the second liquid level sensor 34. If it has fallen, this control is immediately terminated to prevent the steam in the system from flowing into the reservoir tank 21.

Further, for the same reason, even when the liquid level in the condenser 3 is below the set level of the second liquid level sensor 34, the water level reduction control in the condenser 3 is not performed.

On the other hand, after the liquid level in the condenser 3 is appropriately controlled as described above, the amount of heat generated by the engine and the amount of heat dissipated from the condenser 3 are approximately balanced at their boiling points, and the system is sealed, the main control The refrigerant temperature control based on the refrigerant temperature control and the refrigerant temperature control based on the liquid level control using the refrigerant supply pump 4 are repeatedly performed.

(Fan Control) Only the cooling fan 14 is controlled on/off so as to maintain the system temperature within the set temperature range with higher precision.

Furthermore, in liquid level control, when the liquid level in the cooling jacket 2 falls below a set level, liquid phase refrigerant is supplied from the condenser 3 side to the cooling jacket 2 to maintain the liquid level at the set level.

(Condenser liquid level increase control 'a> In addition, if the system temperature falls below the set temperature range due to disturbances such as an increase in vehicle running wind or changes in the set temperature itself due to changes in operating conditions, the inside of the condenser 3 The liquid level increase control is started. This is a control that suppresses the heat dissipation ability by introducing the liquid phase refrigerant in the reservoir tank 21 to the condenser 3 side and raising the liquid level in the condenser 3. In the embodiment, when introducing the liquid phase refrigerant, forced introduction by driving the refrigerant supply pump 4 in the reverse direction and refrigerant introduction using the pressure difference inside and outside the system are used together. When the inside of the system is in a negative pressure state due to the signal, the third solenoid valve 24 is opened, and the second solenoid valve 17 is set as the B flow path to reduce the pressure difference inside and outside the system through the first auxiliary refrigerant passage 16. Introduce the used refrigerant.

When the inside of the system is under positive pressure, or when the pressure becomes positive during the above-mentioned refrigerant introduction, the third solenoid valve 24 is set to positive, and the refrigerant supply pump 4 is driven in the reverse direction, causing the inside of the condenser 3 to flow from the reservoir tank 21. Liquid phase refrigerant is forcibly introduced into the tank.

If the liquid phase refrigerant in the cooling jacket 2 is insufficient during this refrigerant introduction, the second solenoid valve 17 is switched to the flow path A and the refrigerant supply pump 4 is driven in the forward direction to replenish the refrigerant. .

In this way, the liquid level control inside the condenser 3 can quickly and widely change the heat dissipation capacity of the condenser 3 even when the set temperature changes greatly due to a sudden change in operating conditions, and the resulting change in the amount of condensation can be prevented. Since this has an immediate effect on suppressing and promoting boiling of the refrigerant on the side of the cooling jacket 2, it is possible to follow the set temperature extremely well.

The control of the cooling fan 14 achieves control of the hot water temperature in the system with even higher precision and better responsiveness.

Soil: "Gori-sei-sou" First, by setting the set temperature to 80 degrees Celsius, the liquid level inside the capacitor 3 is controlled to decrease as described above, and the heat dissipation capacity of the capacitor 3 is utilized to the maximum, and the cooling fan 14 is turned on for a predetermined period of time. The system is driven to forcefully cool the system, and the power source is turned off when the temperature inside the system reaches a sufficiently low temperature or a certain period of time has elapsed. When the power is turned off, the first solenoid valve 26, which is a normally closed solenoid valve, is closed, and the third solenoid valve 24, which is a normally open solenoid valve, is opened. The liquid refrigerant is naturally introduced from the reservoir tank 21 through the first auxiliary refrigerant passage 16, and eventually the entire system is filled with liquid refrigerant in preparation for the next startup.

In the evaporative cooling system as described above, the liquid phase refrigerant sent from the refrigerant supply pump 4 is introduced into the cooling jacket 2 in the cylinder block 5 for each cylinder from the refrigerant population 2a of the refrigerant circulation passage 15. Boiling cooling utilizes the latent heat of vaporization of liquid-phase refrigerant, so it does not require a large flow rate of refrigerant compared to cooling with normal cooling water. is boiled in each cylinder and cools the combustion chamber wall 41. The boiling point of the refrigerant at this time is determined by the pressure, so even if the upper space of the cylinder head 6 is communicated with each cylinder to form an independent partitioned space, the pressure inside the cooling jacket 2 is uniform, and therefore the boiling point of the cylinder is also It is uniform between

According to the longitudinally elongated internal combustion engine 1 as in this embodiment, which is equipped with such an evaporative cooling device, the refrigerant in the cooling jacket 2 tends to be biased toward one side in the front and rear when, for example, the vehicle climbs up a hill. However, at this time, due to the presence of the partition walls 42 and 43, the partition spaces for each cylinder are independent and do not communicate with each other at the bottom except for the upper space, so only in each partition space are they separated, as shown in the second figure. It only slopes.

Therefore, firstly, even if the engine is tilted, the combustion chamber wall 41 will not be exposed on the liquid phase refrigerant surface even in the cylinder that is located upward (cylinder #1 in the figure). The second reason is that the partition wall 42. can be prevented from overheating.
43, the liquid phase refrigerant tends to easily flow out from the vapor volume lower depending on the direction of the deviation due to the deviation of the refrigerant when there is no 43. By preventing the large deviation, this can be prevented. It is possible to prevent the heat dissipation efficiency of the capacitor 3 from decreasing due to the removal of the heat, and to perform the above-mentioned internal refrigerant temperature control over a wide range with good responsiveness. And thirdly, the first liquid level sensor 32. Since the temperature sensor 33 and the like will not make false detections due to unevenness of the refrigerant liquid level, this type of boiling cooling system can be operated accurately and stably.

In the above embodiment, the first liquid level sensor 32 is provided above the cylinders at both ends of #1 and #6, but it may be provided in other positions in the cylinder, or only a single liquid level sensor. The refrigerant population 2a of the circulation passage 15 is not necessarily provided for each cylinder or for each partition space (in the case of partitioning into a plurality of spaces regardless of the cylinder), but the refrigerant is introduced only into the jacket part of one cylinder or one partition space. In this case, the refrigerant overflows from the upper end of the partition wall 42 of the cylinder head 6 into the adjacent partition space, and the partition spaces are sequentially filled with the refrigerant. It is desirable to provide it at a position in the partition space farthest from the refrigerant population 2a.

<Effects of the Invention> As described above, according to the present invention, since the cooling jacket of the internal combustion engine is independently partitioned with partition walls except for the upper space, the refrigerant liquid level does not incline significantly with respect to the inclination of the engine. This makes the liquid level sensor.

There is no erroneous detection of liquid level or refrigerant temperature by temperature sensors, etc., and there is also less risk of liquid phase refrigerant being taken out from the vapor outlet to the condenser, so the control accuracy of the evaporative cooling system can be significantly improved. This approach can prevent the combustion chamber wall from overheating. Furthermore, since a separate partition plate is attached to the cylinder block side partition wall after the cylinder block is cast, casting the cylinder block is easy and productivity is improved.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of an evaporative cooling device showing one embodiment of the present invention, Fig. 2 is a longitudinal cross-sectional view along the cylinder row of the internal combustion engine, and Fig. 3 is a cross-sectional view taken along the line m-m of the same. , Figure 4 is the second
5 is a sectional view taken along the line V-V in FIG. 2, and FIG. 6 is a flowchart showing the basic control of the evaporative cooling device in this embodiment. 1... Internal combustion engine 2... Cooling jacket l-2A.

Claims (1)

[Scope of Claims] A cooling jacket for an internal combustion engine in which a predetermined amount of liquid phase refrigerant is stored, a condenser in which a gas phase refrigerant is condensed and the condensed liquid phase refrigerant is stored in the lower part, and a cooling jacket for liquid phase refrigerant circulation. In a multi-cylinder internal combustion engine equipped with a refrigerant supply pump and a boiling cooling device that absorbs heat in a cooling jacket and dissipates the latent heat of the vaporized refrigerant in a condenser, the cooling A partition wall is provided that communicates the upper space facing the steam outlet of the jacket part and separates and defines the lower space into a plurality of parts in the cylinder row direction, and in the cooling jacket part in the cylinder block,
A partition wall is provided to separate and define the cooling jacket part into a plurality of parts in the direction of the cylinder row, and the corresponding partitioned cooling jacket parts of the cylinder head and the cylinder block are vertically connected to each other to constitute the cooling jacket, and A multi-cylinder internal combustion engine equipped with an evaporative cooling device, characterized in that the partition wall of the cylinder block is formed by attaching a separate partition plate to a cast cylinder block body.