JP2003083063A - Cooling device for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve flow rate balance of refrigerant flowing in a plurality of cylinder groups and ensure required flow rate sufficiently even when using heating equipment in heating equipment of an indoor part for a wide vehicle room space by corresponding to the wide vehicle room space of a vehicle loaded with a large displacement engine. SOLUTION: In a cooling device for the engine provided with refrigerant passages 8A, 8B, 9A, 9B independent every cylinder group of a plurality of cylinder groups 2, 3 and having a refrigerant circulation passage including the independent refrigerant passages, introducing refrigerant from a feed pump 11 into each of independent refrigerant passages, collecting the refrigerant coming out of each of independent refrigerant passages to lead it into a heat exchanger 18, and then returning the refrigerant into the feed pump 11, refrigerant for equipment 31 for cooling is taken out of the refrigerant circulation passage 8B on a cylinder group side on one side on the downstream side of the feed pump, and refrigerant for equipment 35 for heating is taken out of a refrigerant circulation passage 10A on a cylinder group side on the other side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine cooling device.

[0002]

2. Description of the Related Art As a cooling device for a V-type engine, there is a cooling device which distributes a coolant (cooling water) to two banks in order to improve the cooling efficiency of the outer wall of a cylinder and the outer wall of a combustion chamber.

[0003]

By the way, there are various kinds of devices (devices) that require a refrigerant, and the place where the refrigerant is taken out is determined by the use of each device. For example, in the case of an oil cooler (cooling device), in order to cool the oil, the refrigerant must be taken out from a cold place (between the water pump as a feed pump and the water jacket in the engine).

However, since the water pump is usually fixed to the cylinder block, it is very difficult in layout to take out the refrigerant before the water pump enters the water jacket. Therefore, in the case of distributing to two banks like the above-mentioned conventional device, the structure is such that the refrigerant to the oil cooler is taken out from the refrigerant circulation passage on one bank side downstream of the water pump. Becomes worse, which affects the cylinder heat radiation amount and the combustion chamber heat radiation amount of the two banks.

Therefore, in the present invention, an independent refrigerant passage is provided for each of the plurality of cylinder groups, and the refrigerant from the feed pump is introduced into each independent refrigerant passage including the independent refrigerant passage and the independent refrigerant passage is introduced. After collecting the refrigerants from the respective refrigerant passages and guiding them to the heat exchanger, when there is a refrigerant circulation path for returning to the feed pump, both the refrigerant to the cooling device and the refrigerant to the heating device are combined. When taking out, the refrigerant to the cooling equipment is taken out from the refrigerant circulation path on the one cylinder group side downstream of the feed pump, and the refrigerant to the heating equipment is taken out from the refrigerant circulation path on the other cylinder group side. An object of the present invention is to improve the balance of the flow rate of the refrigerant flowing through the cylinder group.

[0006]

According to a first aspect of the present invention, an independent refrigerant passage is provided for each cylinder group of a plurality of cylinder groups, and the refrigerant from a feed pump (for example, a water pump) includes the independent refrigerant passage ( For example, cooling water) is introduced into each of the independent refrigerant passages, and the refrigerant exiting each of the independent refrigerant passages is collected and guided to a heat exchanger (for example, a radiator) and then returned to the feed pump. In the engine cooling device having, the refrigerant to the cooling device is taken out from the refrigerant circuit on the one cylinder group side downstream of the feed pump, and the refrigerant to the heating device is taken from the refrigerant circuit on the other cylinder group side. .

According to a second aspect of the present invention, in the first aspect of the present invention, when the engine is a V-type engine having two banks, the one cylinder group remains in any of the two banks and the other cylinder group remains. Is a bank of.

According to a third aspect of the present invention, in the first or second aspect, the engine displacement is 4.5 liters or more.

In a fourth aspect of the invention, in any one of the first to third aspects of the invention, the refrigerant flowing through the refrigerant passage flows through the cylinder block in the cylinder group row direction, and thereafter the cylinder head is directed in the opposite direction to this flow direction. In the U-turn flow that flows in the cylinder group row direction, the take-out point of the refrigerant from the heating device is the point where the refrigerant has finished flowing in the cylinder group row direction in the cylinder block.

In a fifth aspect of the present invention, in any one of the first to fourth aspects of the present invention, the extraction location is on the passenger compartment side in the cylinder row group direction.

[0011]

According to the first and second aspects of the present invention, when the refrigerant is distributed and flowed to a plurality of cylinder groups (two banks), the location where the refrigerant is taken out to the cooling equipment and the heating equipment. Since the locations where the refrigerant is taken out of the cylinders are allocated to a plurality of cylinder groups (two banks) so as not to be biased only to the refrigerant circulation path on one cylinder group side, the flow rate balance between the plurality of cylinder groups is improved, and The amount of heat released from the combustion chamber between cylinder groups (between banks)
Can be equalized with.

Further, in the first and second aspects of the invention, since the location where the refrigerant is taken out to the heating device is the refrigerant circulation path on the side of the other cylinder group, the location where the refrigerant circulation paths of the plurality of cylinder groups join is determined. Since the water flow resistance is smaller than that in the case where it is taken out, a sufficient refrigerant flow rate can be secured.

Further, in a vehicle equipped with a large displacement engine as in the third aspect of the invention, since the passenger compartment is large, when the refrigerant is supplied to the heating device as a heating device for the passenger compartment, the refrigerant circulation path is used. The resistance when flowing to becomes large. Therefore, the effect of improving the flow rate balance between the cylinder groups (banks) is particularly remarkable as compared with the case where the refrigerant is taken out from one of the cylinder groups (banks) to the cooling device and the heating device. Further, since it is possible to secure a sufficient flow rate of the refrigerant to the heating device, it is possible to shorten the temperature rise time and obtain a uniform temperature rise distribution when raising the temperature in the vehicle interior.

According to the fourth aspect of the invention, the U-turn flow is such that the refrigerant flowing through the refrigerant passage flows through the cylinder block in the cylinder group row direction, and then flows through the cylinder head in the cylinder group row direction opposite to the flow direction. Since the point of taking out the refrigerant of the heating device is the point where the refrigerant has finished flowing through the cylinder block in the cylinder group row direction, the cylinder head is used as the vehicle interior heating device, and the refrigerant heated to a high temperature by the cylinder block is taken out. Further, according to the fifth aspect of the invention, the heat pipe for introducing the high-temperature refrigerant into the vehicle compartment can be shortened, so that the cost can be suppressed and the unnecessary heat loss can be suppressed. The temperature rise efficiency can also be improved.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a cooling system diagram when the present invention is applied to a cooling device for a V-type engine adopting a U-turn flow. The U-turn flow V-type engine 1 has two banks 2 and 3, and each bank 2 and 3 is composed of cylinder blocks 4 and 5 located at the bottom and cylinder heads 6 and 7 at the top.

The U-turn flow V-type engine 1 is mounted vertically in front of a vehicle compartment (not shown), and a radiator 18 (heat exchanger) is arranged further in front of the engine 1. Therefore, although the bank 2 is located on the left side in the figure, it is called the "right bank", and the bank 3 is located on the right side in the figure, but it is called the "left bank".

In each of the banks 2 and 3, four passages (water jackets) 8A, 8B, 9A and 9B in which cooling water (refrigerant) flows independently of the cylinder block and the cylinder head.
Are formed, and the two cooling water passages 8A and 9A of the right bank 2 are formed.
Is connected to the rear (upper side in the figure) by the communication passage 10A, and the two cooling water passages 8B and 9B of the left bank 3 are also connected to the rear by the communication passage 10B. In this case, the water inlets 13A, 13B, the water outlet 15A,
Both 15B are in front of the engine (downward in the figure).

A water pump 11 driven by a crankshaft (not shown) at the front end of the engine 1.
(Feed pump) is attached. The pair of outlets 11a and 11b of the water pump 11 are the same as the pair of passages 1
The cooling water passages 8A and 8B in the cylinder blocks 4 and 5 are connected via 2A and 12B.

The cooling water passages 16A and 16B connected to the pair of outlets 15A and 15B are combined into one passage 17, and this collecting passage 17 is connected to the inlet 18a of the radiator 18 located in front of the vehicle and is connected to the radiator 18 of the radiator 18. The outlet 18b is connected to the inlet 11c of the water pump 11 via a passage 19.

In this way, the passage 12A, the cooling water passage 8A in the cylinder block, the communication passage 10A, the cooling passage 9A in the cylinder head, the passage 16A, the collecting passage 17, the passage 1
The cooling water circulation path (refrigerant circulation path) on the right bank 2 side from 9
In addition, the passage 12B, the cooling water passage 8B in the cylinder block,
The communication passage 10B, the cylinder head internal cooling passage 9B, the passage 16B, the collecting passage 17, and the passage 19 constitute a cooling water circulation passage (refrigerant circulation passage) on the left bank 3 side.

Further, the radiator 18 and the water pump 1
A thermostat 20 is provided in the passage 19 connecting the 1's. 22 is a reserve tank.

In the figure, the flow direction of the cooling water is indicated by an arrow, and after the engine 1 has been warmed up, the cooling water discharged by the water pump 11 is discharged from the outlets 11a and 11b into a pair of passages 12A and 12B. Flow through the cooling water passages 8A and 8B in the cylinder blocks 4 and 5 through the cooling water passages 8A and 8B to flow from the front of the vehicle toward the rear of the vehicle to exchange heat with the cylinder blocks 4 and 5. I do. Due to this heat exchange, the temperature of the cooling water rises and reaches the rear end of the engine.
A, 10B then flows into the cooling water passages 9A, 9B in the cylinder head and then flows through the cooling water passages 9A, 9B from the rear side of the vehicle to the front side of the vehicle.
Heat exchange with 7. Due to this heat exchange, the temperature of the cooling water further rises to reach the front end of the engine, and the cooling water reaching the front end of the engine passes through the communication passages 16A and 16B to
Collected in one flow. It is led to the radiator 18.
Here, it is cooled by exchanging heat with the outside air.

In this way, after the cooling water flows from the front end of the engine to the rear end of the engine in the cylinder row direction, this time, in the opposite direction, from the rear end of the engine to the front end of the engine in the cylinder row direction, a U-turn flow method is adopted. According to this U-turn flow, temperature management is easy because only two points, that is, the cylinder blocks 4 and 5 and the cylinder heads 6 and 7, need to be temperature controlled, and the number of parts is small and the cooling system is simplified. Has the advantage that it is possible.

The cooling water cooled to a low temperature by the radiator 18 is returned to the water pump 11 again.

In this case, since the engine 1 has a large displacement (for example, 4.5 liters or more), the passage 17
Is provided with a passage 21 that bypasses the radiator 18, and a constant flow rate of cooling water is always circulated in the engine 1 by this passage 21. Such a method is commonly called constant bypass.

When the temperature of the cooling water is low, the valve is throttled by the thermostat 20 to reduce the flow rate of the cooling water flowing through the radiator 18, while when the temperature of the cooling water is high, the valve is opened. The flow rate of the cooling water flowing through the radiator 18 is increased, whereby the temperature around the combustion chamber of the engine 1 is maintained at an appropriate value.

On the other hand, an oil cooler 31 (cooling device) is provided for cooling the lubricating oil of the turbocharger, and a heater 35 (heating device) is provided for heating a large passenger compartment.
Equipped with. The cooling water to the oil cooler 31 is the engine 1
In order to take out the cooling water before being heated by, the cooling water is taken out from the cooling water passage 8B near the front end of the engine of the left bank 3 (near the first cylinder). That is, the passage 32 is branched from the cooling water passage 8B near the first cylinder of the left bank 3, and the branch passage 32 is connected to the inlet 31a of the oil cooler 31.
Connected to. The cooling water whose temperature has risen due to heat exchange in the oil cooler 31 is returned from the outlet 31 b of the oil cooler 31 to the upstream side of the water pump 11 via the return passage 33. An EGR cooler (which cools EGR gas) can be considered as a substitute for the oil cooler 31.

Here, in the case of a heater (heating device) as a vehicle interior heating device, in order to heat the vehicle interior, it is better to take out the refrigerant from a high temperature portion (near the engine outlet) 15A. good. However, since this part is located on the most downstream side of the cooling water flowing through the engine 1 as viewed from the water pump 11, the cooling water flow rate is largely reduced due to the water flow resistance. In this case, particularly when considering a vehicle equipped with a large-displacement engine, the passenger compartment also becomes large, so that the flow rate of the cooling water required for the heater 35 increases corresponding to the size of the passenger compartment space. Therefore, 15A near the engine exit
Even if the location where the cooling water is at a high temperature is taken out to the heater 35, the flow velocity of the cooling water is reduced due to the water flow resistance from the water pump 11 to the taken out location, and the required flow rate to the heater 35 is reduced. May not be ensured, the temperature distribution in the vehicle compartment may become uneven, and a wide vehicle interior space may not be sufficiently warmed up, which may cause an unfavorable situation.

Therefore, the heater 3 as a vehicle interior heating device
The cooling water to 5 is taken out from the rear end portion of the cylinder head 6 of the right bank 2 which can secure an appropriate cooling water temperature and flow rate. That is, the passage 36 is branched from the communication passage 10A at the rear end of the cylinder head 6 of the right bank 2, and the branch passage 36 is connected to the inlet 35a of the heater 35.
The cooling water whose temperature has decreased due to heat exchange in the heater 35 is returned from the outlet 35 b of the heater 35 to the upstream side of the water pump 11 via the return passage 37.

In this way, the cooling water is taken out to the oil cooler 31 from the cooling water passage 8B near the first cylinder of the left bank 3, and the cooling water is taken out to the heater 35 from the cylinder head of the right bank 2. 6 trailing passage 1
Since it is set to 0 A, the flow rate balance of the cooling water flowing through the left and right banks 2 and 3 can be made uniform.

Thus, the oil cooler 31 and the heater 35 are
The location where the cooling water was taken out was determined based on the experimental results shown in FIG. This will be explained with reference to FIG.
In FIG. 3, the symbols (1) to (5) at the bottom are the flow rates [L / min] of the cooling water flowing through the connecting passages 10B at the rear end of the left bank, the connecting passages 10A at the rear end of the right bank, and the collecting passages 17 shown in FIG. Among these, the water flow resistance is the most downstream in the case of being the most downstream from the water pump 11, and is the smallest in the three. Further, in the case of, the water flow resistance is smaller than in the case of, so that the flow rate is increased accordingly.

In the case of the oil cooler 31, for the purpose of cooling the oil, the cooling water must be taken out from a place where the cooling water has a low temperature, that is, immediately downstream of the water pump 11. Since the water pump 11 is actually fixed to the cylinder block, it cannot be taken out from the passage 12B, so that it is taken out from the cooling water passage 8B near the first cylinder. At this time, the oil cooler, the cylinder block of the right bank (specifically the point of FIG. 3), the cylinder block of the left bank (specifically the point of FIG. 3),
This is the case where the result of measuring the flow rate flowing through is in the middle of FIG. Here, 51% and 49% of the numbers shown in parentheses are 100% of the total flow rate in the cylinder blocks of the left and right banks.
It is a percentage when it is defined as%. From the same number, when taking out the cooling water to the oil cooler 31 as the left bank,
Since the variation between the left and right banks worked better, it can be seen that the flow rate in the cylinder blocks of the left and right banks is better balanced than in the case of the middle stage.

In the middle stage, when the cooling water for the oil cooler 31 is taken out from the cooling water passage 8A near the front row cylinder of the right bank, the oil cooler and the cylinder block of the right bank (specifically, Points in Figure 3),
As a result of measuring the flow rate flowing through the cylinder block of the left bank (specifically, the point in FIG. 3), if the cooling water is taken out from the cooling water circulation passage on the right bank side in this way, the cylinder blocks of the left and right banks are The flow rate balance will be greatly disrupted.

Next, the heater 35 as a vehicle interior heating device.
In the case of, in order to heat the passenger compartment, the cooling water must be taken out from a place where the temperature is high, that is, near the engine outlet. However, as the water flow resistance becomes greater toward the downstream side of the water pump 11, a sufficient flow rate cannot be secured, and the left and right banks are connected while the cooling water is taken out to the oil cooler 31 from the cooling water circulation path on the left bank side. Heater 3 to improve the flow balance
Taking into consideration two things that it is better to use the cooling water circulation path on the right bank side as the extraction location of the cooling water to 5, the extraction location of the cooling water to the heater 35 is set to the cooling water circulation path on the right bank side,
Moreover, the connecting passage 10A is provided at the rear end of the right bank where the water resistance is smaller than that at the engine outlet. At this time, the results of measuring the flow rates of the oil cooler, the heater, the cylinder head of the right bank (specifically the point of FIG. 3) and the cylinder head of the left bank (specifically the point of FIG. 3) are shown in FIG. In the case of the upper row. 46 on the cylinder head of the right bank
%, 54% of the cooling water flows to the cylinder head of the left bank. Here, 46% and 54% are percentages when the total flow rate of the cylinder heads of the left and right banks is 100%. It can be seen that the flow rate balance flowing through the cylinder heads of the left and right banks is better than in the case above the same number.

In the case of the upper stage, the oil cooler, the heater, and the cylinder head of the right bank when the cooling water for the heater 35 is taken out from the communication passage 10B at the rear end of the left bank (specifically, as shown in FIG. 3)) and the cylinder head of the left bank (specifically, the point of FIG. 3), the flow rate is measured. As described above, not only the oil cooler 31 but also the heater 35 from the cooling water circulation passage on the left bank side are measured. When taking out the cooling water to the cylinder heads as well, the flow rate balance flowing through the cylinder heads 6 and 7 of the left and right banks is greatly disturbed.

In the case of the upper stage of FIG. 2, the conclusion obtained by the experiment as described above is that the cylinder blocks 4, 5 and the cylinder heads 6, 7 of the left and right banks 2, 3 have a substantially equal flow rate balance, and the heater is Even if the flow rate flowing through 35 is compared with other extraction methods, it can be sufficiently ensured.

Returning to FIG. 1, reference numeral 40 denotes a throttle chamber, through which warmed cooling water is caused to flow in order to prevent a throttle valve (not shown) from sticking due to freezing. Since the flow rate of the cooling water for warming the throttle chamber 40 is not so large, the passage 41 is branched from the collecting passage 17 where the highest temperature cooling water can be obtained as in the conventional case, and the branch passage 41 is connected to the throttle chamber 40. To be done. The cooling water, whose temperature has dropped due to heat exchange in the throttle chamber 40, is returned to the upstream side of the water pump 11 via the return passage 42.

As described above, according to the present embodiment, when the cooling water is distributed to the left and right banks 2 and 3 (a plurality of cylinder groups), the oil cooler 31 (cooling device) is cooled. The water take-out point and the cooling water take-out point to the heater 35 (heating device) are assigned to the left and right banks 2 and 3 so as not to be biased only to the cooling water circulation path of one bank (cylinder group side). The flow rate balance between the banks is improved, and the heat radiation amounts of the cylinder and the combustion chamber can be equalized between the banks.

Further, in the present embodiment, since the cooling water circulation passage (communicating passage 10A) before the merging of the two cooling water circulation passages is not formed after the two cooling water circulation passages are merged, the left and right banks are arranged. The water flow resistance can be made smaller than the case where the location where the cooling water circulation passages merge (collection passage 17) is used as the extraction location. Therefore, in a vehicle equipped with a large displacement engine, the interior of the vehicle is wide, and even when the heater 35 is used as a device for heating the interior of the large vehicle, a sufficient flow rate of the cooling water can be secured. Even if the interior space is large, the temperature rise time can be shortened and a uniform temperature distribution can be obtained in the passenger compartment.

The U-turn flow V-type engine 1 is vertically mounted in front of the passenger compartment and the radiator 1 is installed.
When 8 (heat exchanger) is arranged further in front of the engine 1, the temperature of the cooling water becomes the highest at the front end of the engine where the cooling water outlet (water outlet) from the engine 1 is, and Since the front end of the engine where the high-temperature cooling water is obtained is taken as the location where the cooling water is taken out to the heater 35 as a device, the heat pipe for guiding the high-temperature cooling water to the vehicle compartment located behind the engine is long. However, according to the present embodiment, since the portion (communication passage 10A) where all the cylinder blocks have flowed in the cylinder row direction is the rear end of the engine close to the vehicle interior, The heat pipe for guiding the high temperature cooling water may be short, and the cost does not increase.

In the embodiment, the place where the cooling water is taken out to the oil cooler 31 is the cooling water circulation path on the left bank side and the heater 3
Although the description has been made in the case where the cooling water take-out point to 5 is the cooling water circulation path on the right bank side, the cooling water take-out point to the oil cooler 31 is the cooling water circulation path on the right bank side and the heater 3
The cooling water circulation path on the left bank side may be used as the outlet for cooling water to No. 5.

In the embodiment, the case where the present invention is applied to the U-turn flow V-type engine has been described, but the present invention is not limited to this, and the present invention is also applied to a so-called vertical flow or transverse flow V-type engine. be able to. Further, the engine is not limited to the V type. It does not matter even if the V-type engine of U-turn flow is mounted horizontally on the vehicle.

[Brief description of drawings]

FIG. 1 is a cooling system diagram of a first embodiment when the present invention is applied to a U-turn flow V-type engine.

FIG. 2 is a characteristic diagram showing a comparison of the flow rates at various parts due to the difference in the cooling water extraction points.

FIG. 3 is a cooling system diagram for showing the extraction point of the cooling water used in FIG.

[Explanation of symbols]

2-3 banks (cylinder group) 4, 5 cylinder block 6, 7 cylinder head 8A, 8B Cooling water passage in cylinder block 9A, 9B Cooling water passage in cylinder head 11 Water pump (feed pump) 18 radiator (heat exchanger) 31 Oil cooler (cooling equipment) 35 Heater (heating equipment) 40 Throttle chamber

Claims (5)

[Claims] 1. An independent refrigerant passage is provided for each cylinder group of a plurality of cylinder groups, and a refrigerant from a feed pump is introduced into each independent refrigerant passage including the independent refrigerant passage, and each independent refrigerant passage is introduced. In an engine cooling device having a refrigerant circulation path that collects the refrigerant that has exited the passage and guides it to the heat exchanger, and then returns the refrigerant to the cooling device to one of the cylinder groups on the downstream side of the feed pump. The cooling device for an engine is characterized in that the refrigerant to the heating device is taken out from the refrigerant circulating path of the above, and the refrigerant to the heating device is taken out from the refrigerant circulating path of the other cylinder group side. 2. When the engine is a V-type engine having two banks, the one cylinder group is one of the two banks and the other cylinder group is the remaining bank. The engine cooling device according to claim 1. 3. The engine cooling device according to claim 1, wherein the engine displacement is 4.5 liters or more. 4. A U-turn flow in which a refrigerant flowing through the refrigerant passage flows through a cylinder block in a cylinder group row direction and then through a cylinder head in a cylinder group row direction opposite to the flow direction. The engine cooling device according to any one of claims 1 to 3, wherein the refrigerant is taken out from the device at a position where the refrigerant has finished flowing in the cylinder block row direction. 5. The engine cooling device according to any one of claims 1 to 4, wherein the extraction location is on the passenger compartment side in the cylinder group row direction.