JP6990081B2 - Oil pan heat insulation cooling structure - Google Patents

Description

The present invention relates to a heat-retaining cooling structure for an oil pan in which the oil pan is surrounded by a heat storage material so that the temperature of the stored engine oil is maintained at an appropriate level.

The engine oil stored in the oil pan has a high viscosity because the temperature is low in the cold state, while the viscosity becomes low because the temperature rises during the high load operation. Therefore, at the time of cold start, the friction of the sliding portion increases due to the high viscosity of the engine oil, which causes deterioration of fuel efficiency. On the other hand, high temperature of the engine oil during high load operation causes deterioration to be accelerated.

Therefore, it is desirable to promote the temperature rise of the engine oil at the time of cold start, and to cool the engine oil at the time of high load operation to suppress the temperature rise.

For example, in Patent Document 1 (Japanese Unexamined Patent Publication No. 2001-355421), the outer periphery of an oil pan is covered with an oil cover, and a flow path for passing running air through a gap formed between the oil pan and the oil cover is provided. An open / close valve that opens and closes the flow path is provided on the front of the oil pan cover, and this open / close valve is opened and closed by a heat-sensitive rod with a built-in thermowax. Disclosed is a technique for keeping warm by cooling the oil and closing the on-off valve when it is in a cold state.

Japanese Unexamined Patent Publication No. 2001-355421

However, in the technique disclosed in the above-mentioned document, the inside of the passage formed on the outer periphery of the oil pan at the time of cold start is almost the same as the outside air temperature, so that the viscosity of the engine oil is high and the warm-up operation is performed. It is difficult to complete the above at an early stage, and there is a limit to improving fuel efficiency.

On the other hand, during high-load operation, it is better to expose the oil pan to the outside air as it is to obtain an efficient heat dissipation effect, and having a double structure on the outer circumference of the oil pan rather hinders the heat dissipation.

In view of the above circumstances, the present invention can appropriately maintain the temperature of the engine oil at the time of cold start and in high load operation with a simple structure, and can improve fuel efficiency and suppress the progress of deterioration. It is an object of the present invention to provide an oil pan heat insulation cooling structure.

The present invention includes an oil pan and a cover portion that surrounds the outer periphery of the oil pan via a gap, and the gap between the oil pan and the cover portion is filled with a heat storage material to keep the oil pan warm and cool. In the above, the heat storage material storage portion provided in the cover portion, the communication portion communicating the gap filled with the heat storage material in the cover portion and the heat storage material storage portion, and the communication portion are arranged. It is provided with an opening / closing portion that opens / closes according to the expansion / contraction of the heat storage material to adjust the pressure of the heat storage material .

According to the present invention, the gap between the gap and the cover portion surrounding the outer periphery of the oil pan is formed, and the heat storage material is filled in the gap. The temperature can be properly maintained, and in the cold state, the heat is insulated by the solidified heat storage material or heated by the heat stored in the heat storage material, so that the warm-up time can be shortened. As a result, with a simple structure, it is possible to improve fuel efficiency by shortening the warm-up time and suppress deterioration progress by appropriately maintaining the temperature of the engine oil.

Cross-sectional side view of the oil pan and its surroundings according to the first embodiment Cross-sectional side view of the oil pan and its surroundings according to the second embodiment The same, schematic configuration diagram of the oil pan heating / cooling control unit The same flow chart showing the temperature adjustment processing routine of the heat storage material. Cross-sectional side view of the oil pan and its surroundings according to the third embodiment The same, schematic configuration diagram of the oil pan heating / cooling control unit The same flow chart showing the temperature adjustment processing routine of the heat storage material.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 shows a first embodiment of the present invention. Reference numeral 1 in the figure is the front part of the vehicle, and the engine room 1a is formed inside.

The engine 2 is mounted in the engine room 1a, an oil pan 3 made of a material having high heat dissipation is fixedly attached to the bottom surface of the engine 2, and a transmission 4 is continuously provided at the rear end. ing. Further, the bottom surface of the engine room 1a, that is, the lower portion of the oil pan 3, is covered with the undercover 5.

Engine oil is stored in the oil pan 3, and is circulated while the engine is in operation to lubricate each lubrication-required portion and also has a cooling function.

Further, a heat storage unit 6 is arranged on the outer periphery of the oil pan 3. The heat storage portion 6 has a heat storage cover 6a as a cover portion that surrounds the outer periphery of the oil pan 3 by opening a predetermined gap portion, and a heat storage material 6b is filled between the heat storage cover 6a and the outer surface of the oil pan 3. Has been done. The heat storage material 6b is, for example, a latent heat storage material using paraffin as a main raw material, and heat is stored at the time of phase transition of solid, liquid, and gas.

A heat storage material storage unit 7 is provided on the side surface of the heat storage unit 6. The heat storage material storage portion 7 is a pressure adjusting chamber , and regulates the pressure increase in the void portion due to volume expansion when the heat storage material 6b is liquefied and vaporized. The communication pipes 8a and 8b are communicated with each other via 8b, and pressure adjusting valves 6c and 6d as opening / closing portions are interposed in the communication pipes 8a and 8b.

The pressure control valves 6c and 6d are one-way valves, the upper pressure control valve 6c allows only the heat storage material 6b to flow from the heat storage unit 6 to the heat storage material storage unit 7, and the lower pressure control valve 6d is the heat storage material. Only the outflow of the heat storage material 6b from the storage unit 7 to the heat storage unit 6 is allowed.

In such a configuration, the heat storage material 6b of the heat storage unit 6 is solidified at the time of cold start, and functions as a heat insulating material. Therefore, during the cold start and the warm-up operation after the start, the cooling of the engine oil through the oil pan 3 is suppressed, the warm-up operation can be completed at an early stage, and the fuel efficiency can be improved.

Then, with the temperature of the engine oil accompanying the rise in the engine temperature after the completion of warm-up, the heat storage material 6b loaded on the outer periphery of the oil pan 3 is gradually melted, and heat is stored by the latent heat at that time.

Further, when the engine temperature further rises due to the high load operation, the temperature of the engine oil also rises accordingly, and the heat storage material 6b is further stored by latent heat via the oil pan 3. After that, when the temperature of the engine oil further rises, the latent heat of vaporization of the heat storage material 6b suppresses the temperature rise of the engine oil, and the progress of deterioration is suppressed by that amount.

By the way, the volume of the heat storage material 6b expands in the phase transition of liquefaction and vaporization. Then, the pressure control valve 6c provided on the upper part of the heat storage material storage part 7 opens due to the differential pressure, and the liquefied or vaporized heat storage material 6b flows into the heat storage material storage part 7 and the pressure inside the heat storage part 6 rises. Is suppressed. After that, when the heat storage material 6b of the heat storage unit 6 liquefies and the volume shrinks, the pressure adjusting valve 6c at the lower part opens due to the differential pressure, and the heat storage material 6b in the heat storage material storage unit 7 flows into the heat storage unit 6 side. Then the pressure is adjusted.

On the other hand, when the engine 2 is stopped, the temperature of the engine oil gradually decreases, but the outer surface of the oil pan 3 is covered with the heat storage portion 6, and the heat storage of the heat storage material 6b suppresses the temperature decrease of the engine oil.

As a result, when the engine 23 is cold-started from the state of being left unattended after the engine is stopped, the engine oil is kept warm to some extent by the heat storage of the heat storage material 6b and the heat insulating action, so that not only good startability can be obtained but also good startability can be obtained. It is possible to improve fuel efficiency by shortening the warm-up time.

[Second Embodiment]
2 to 4 show a second embodiment of the present invention. In the first embodiment described above, the pressure of the heat storage material 6b at the time of phase transition is adjusted by the differential pressure, but in the present embodiment, the heat storage material storage portion 7 is provided with a cooling function, and the heat storage material 6b is used. In the case of overheating, it becomes difficult to effectively cool the engine oil, so that the engine oil is released to the heat storage material storage unit 7 to be cooled.

Therefore, the heat storage material storage portion 7 is preferably made of a metal such as aluminum or iron having high heat dissipation. The same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

That is, as shown in FIG. 2, the pump valve 9 having a function as an opening / closing portion in the communication pipe 8 as a communication portion for communicating the gap portion filled with the heat storage material 6b of the heat storage portion 6 and the heat storage material storage portion 7. Is interspersed. The pump valve 9 is flowed or shut off while the pump is stopped, and the liquefied heat storage material 6b flows in and out from one side to the other when the pump is operated. In the following, for convenience, the rotation direction of the pump valve 9 will be described as the normal rotation of the flow of the heat storage material 6b from the heat storage unit 6 to the heat storage material storage unit 7 and the reverse rotation of the flow in the reverse direction.

The pump valve 9 is controlled to rotate forward, reverse, and stop by the controller 11 shown in FIG. The controller 11 is mainly composed of a well-known microcomputer having a CPU, a ROM, a RAM, a non-volatile memory, and the like, and various programs executed by the CPU, various fixed data, and the like are stored in the ROM.

A temperature sensor 16 for detecting the temperature of the heat storage material 6b is connected to the input side of the controller 11, and the pump valve 9 described above is connected to the output side.

The controller 11 controls the operation of the pump valve 9 according to the temperature adjustment processing routine shown in FIG. Since the phase transition of the heat storage material 6b due to the temperature change of the engine oil (oil pan 3) is the same as that of the first embodiment, the description thereof is omitted here. Further, the temperature of the heat storage material 6b and the expansion coefficient are closely related, and in the liquid phase, the volume expands almost proportionally as the temperature rises.

In the routine shown in FIG. 4, first, the temperature of the heat storage material 6b filled in the heat storage unit 6 detected by the temperature sensor 16 in step S1 is read.

Next, the process proceeds to step S2, and it is checked whether or not the temperature of the heat storage material 6b is equal to or less than the threshold value. This threshold value is set, for example, based on the temperature at which the heat storage material 6b undergoes a phase transition to a liquid phase or a gas phase.

Then, when the temperature of the heat storage material 6b is equal to or lower than the threshold value, the process jumps to step S7. On the other hand, if the threshold value is exceeded, the process proceeds to step S3 in order to cool the heat storage material 6b.

In step S3, the pump valve 9 is rotated in the normal direction, a part of the heat storage material 6b in the heat storage unit 6 is made to flow into the heat storage material storage unit 7, the process proceeds to step S4, and the pump valve 9 is positive until the set time elapses. Maintain the rolling state. As a result, a part of the heat storage material 6b of the heat storage unit 6 flows into the heat storage material storage unit 7.

After that, the process proceeds to step S5, the pump valve 9 is stopped, and the pump valve 9 is made to stand by for a predetermined cooling time. This cooling time is the time for the temperature of the heat storage material 6b to drop to the set temperature, which is a fixed time obtained in advance based on an experiment or the like, but is obtained based on the temperature of the heat storage material 6b flowing into the heat storage material storage unit 7. It may be a variable value.

Then, after a predetermined cooling time has elapsed, the process proceeds to step S6, the pump valve 9 is reversed, and the heat storage material 6b retained in the heat storage material storage unit 7 is returned to the heat storage unit 6. By returning the heat storage material 6b that has been cooled to the heat storage unit 6, the temperature of the heat storage material 6b filled in the heat storage unit 6 is lowered.

Then, the process proceeds to step S7, the reverse state of the pump valve 9 is maintained until the set time elapses, and then the process proceeds to step S8. When the process proceeds from step S2 or step S7 to step S8, the pump valve 9 is stopped, the communication pipe 8 is closed, and the routine is exited.

As described above, in the present embodiment, when the temperature of the heat storage material 6b of the heat storage unit 6 tends to be overheated and it is determined that it is difficult to cool the engine oil (oil pan 3), a part of the heat storage material 6b is stored in heat. Since the engine oil (oil pan 3) can be properly cooled in high-negative operation or the like, the engine oil (oil pan 3) can be properly cooled because it is evacuated to the material storage unit 7, cooled, and then returned. Overheating can be effectively prevented.
[Third Embodiment]
5 to 7 show a third embodiment of the present invention. In the present embodiment, the heat storage material storage unit 7 of the second embodiment described above is positively cooled. By positively cooling the heat storage material storage unit 7, the standby time for cooling the heat storage material 6b can be shortened. Therefore, the heat storage material 6b can be returned to the heat storage unit 6 at an early stage, and the engine oil (oil pan 3) can be cooled more efficiently. The same components as those in the second embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 5, in the present embodiment, the undercover 5 is formed with an opening 5a capable of blowing a running wind in the direction of the heat storage material storage portion 7, and the opening 5a can be opened and closed by the shutter 10. It was done. Further, a guide portion 12 is fixedly provided on the upper surface of the undercover 5 to guide the traveling wind flowing into the engine room 1a from the opening 5a toward the (bottom surface) of the heat storage material storage portion 7.

The controller 11 operates the pump valve 9 and the shutter actuator 13 for opening and closing the shutter 10 to adjust the temperature of the heat storage material 6b. Specifically, the temperature adjustment of the heat storage material 6b is executed according to the temperature adjustment processing routine shown in FIG. 7. In this temperature adjustment processing routine, in step S3 of the temperature adjustment processing routine of the second embodiment, when the pump valve 9 is rotated in the normal direction, the opening 5a is opened by the shutter 10 and step S8. When the pump valve 9 is stopped, the opening 5a is closed by the shutter 10.

Therefore, the processing of step S3'applied in place of step S3 and step S8'applied in place of step S8 will be described.

In this routine, when the temperature of the heat storage material 6b is determined to be equal to or lower than the threshold value in step S2 and the process proceeds to step S3', the pump valve 9 is rotated in the normal direction and the heat storage material 6b of the heat storage unit 6 flows into the heat storage material storage unit 7. The shutter actuator 13 is operated to open the shutter 10 that closes the opening 5a formed in the undercover 5.

When the opening 5a is opened, a part of the traveling wind that passes from the front through the bottom surface of the undercover 5 to the rear during traveling flows into the engine room 1a from the opening 5a and is guided by the guide portion 12. It is sprayed on the bottom surface of the heat storage material storage portion 7. As a result, the heat storage material 6b flowing into the heat storage material storage unit 7 is cooled at an early stage. Therefore, the waiting time in step S4 can be significantly shortened.

Further, when the pump valve 9 is stopped in step S8', the shutter actuator 13 closes the shutter 10 and exits the routine. By closing the shutter 10, turbulence generated on the bottom surface of the undercover 5 is suppressed, and stable running performance can be obtained.

As described above, in the present embodiment, the undercover 5 is formed with an opening 5a for guiding the traveling air to the heat storage material storage portion 7, and the traveling air is directed to the bottom surface of the heat storage material storage portion 7 on the upper surface of the undercover 5. Since the guide portion 12 that leads to the heat storage material 12 is formed, the running wind can be blown intensively to the heat storage material storage unit 7, and the temperature of the heat storage material 6b can be lowered by that amount at an early stage. As a result, the standby time in step S5 is shortened, the heat storage material 6b can be returned to the heat storage unit 6 at an early stage, and the engine oil (oil pan) can be efficiently cooled.

The present invention is not limited to the above-described embodiments, and for example, the heat storage material storage unit 7 may have cooling fins formed on its outer surface in order to improve heat dissipation.

1 ... Front of the vehicle,
1a ... Engine room,
2 ... engine,
3 ... Oil pan,
4 ... Transmission,
5 ... Undercover,
5a ... opening,
6 ... Heat storage section,
6a ... Heat storage cover,
6b ... Heat storage material,
6c, 6d ... Pressure control valve,
7 ... Heat storage material storage unit,
8,8a, 8b ... Communication pipe,
9 ... Pump valve,
10 ... Shutter,
11 ... Controller,
12 ... Guide section,
13 ... Shutter actuator,
16 ... Temperature sensor

Claims (5)

With an oil pan
With a cover portion that surrounds the outer circumference of the oil pan via a gap
Equipped with
In an oil pan heat insulating and cooling structure in which a heat storage material is filled in the gap between the oil pan and the cover portion .
The heat storage material storage unit attached to the cover unit and
A communication portion that communicates the gap filled with the heat storage material of the cover portion and the heat storage material storage portion, and a communication portion.
An opening / closing portion arranged in the communication portion and opened / closed according to the expansion / contraction of the heat storage material to adjust the pressure of the heat storage material.
An oil pan heat insulation and cooling structure characterized by being equipped with. The oil pan heat insulating / cooling structure according to claim 1, wherein a pump for circulating the heat storage material is provided in the opening / closing portion. The invention according to any one of claims 1 to 2 , wherein the undercover provided below the oil pan has an opening for guiding the traveling wind toward the heat storage material storage portion. Oil pan heat insulation cooling structure. The opening can be opened and closed via a shutter.
The oil pan heat-retaining and cooling structure according to claim 3 , wherein the control means for controlling the opening and closing of the shutter opens the shutter when the heat storage material flows into the heat storage material storage portion. The oil pan heat insulating and cooling structure according to any one of claims 1 to 4 , wherein cooling fins are formed on the outer surface of the heat storage material storage portion.

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