JP3988419B2 - Engine cooling system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an engine cooling device.
[0002]
[Prior art]
As a cooling device for a V-type engine, there is an apparatus that distributes refrigerant (cooling water) to two banks in order to improve cooling efficiency of a cylinder outer wall and a combustion chamber outer wall.
[0003]
[Problems to be solved by the invention]
By the way, there are various types of devices (devices) that require a refrigerant, and the location where the refrigerant is taken out is determined depending on the use of each device. For example, in the case of an oil cooler (cooling device), for cooling the oil, it must be taken out from a location where the refrigerant is cold (between the water pump as a feed pump and the water jacket in the engine).
[0004]
However, since the water pump is usually fixed to the cylinder block in many cases, it is very difficult to take out the refrigerant from the time when the water pump enters the water jacket. Therefore, when distributing to two banks as in the above-mentioned conventional device, the refrigerant is extracted from the refrigerant circulation passage on one bank side downstream of the water pump to the oil cooler. This adversely affects the amount of heat released from the cylinders and the amount of heat released from the combustion chambers of the two banks.
[0005]
Therefore, the present invention includes an independent refrigerant passage for each cylinder group of the plurality of cylinder groups, introduces the refrigerant from the feed pump including the independent refrigerant passage into each independent refrigerant passage, and each independent refrigerant. When the refrigerant that has exited the passage is collected and led to the heat exchanger and then has a refrigerant circulation path that returns to the feed pump, when taking out the refrigerant to the cooling device and the refrigerant to the heating device together, The refrigerant for the cooling device is taken out from the refrigerant circulation path on the one cylinder group side downstream of the feed pump, and the refrigerant for the heating equipment is taken out from the refrigerant circulation path on the other cylinder group side, thereby The purpose is to improve the flow rate balance of the flowing refrigerant.
[0006]
[Means for Solving the Problems]
The first invention includes an independent refrigerant passage for each cylinder group of the plurality of cylinder groups, and the refrigerant flowing through the independent refrigerant passage flows through the cylinder block in the direction of the cylinder group row, and then the cylinder head passes through the flow direction. This is a U-turn flow that flows in the direction opposite to the cylinder group row direction, and includes a refrigerant (for example, cooling water) from a feed pump (for example, a water pump) including this independent refrigerant path and In the cooling system for an engine having a refrigerant circulation path that collects the refrigerant that has exited the independent refrigerant passages, guides the refrigerant to a heat exchanger (for example, a radiator), and then returns the refrigerant to the feed pump, the refrigerant is fed to the cooling device. It is taken out from the refrigerant circulation path in the vicinity of the point to start the flow to the cylinder block of the independent refrigerant passage of one cylinder group side of the pump downstream, car It is taken from the refrigerant circulation path at a place where it has finished flowing cylinder block in the column direction cylinder group of independent refrigerant passage of the refrigerant to the heater as an internal heating appliance other cylinder group side.
In the second invention, in the first invention, the refrigerant to the throttle chamber is taken out from the passages through which the refrigerant exits the independent refrigerant passages.
[0007]
In the third invention, when the engine is a V-type engine consisting of two banks in the first or second invention, the one cylinder group remains in any one of the two banks, and the other cylinder group remains. Bank.
[0008]
In the fourth invention, in any one of the first to third inventions, the engine displacement is 4.5 liters or more.
[0010]
In a fifth aspect of the invention, in any one of the first to fourth aspects of the invention, the refrigerant outlet to the heater is on the side of the compartment in the cylinder row group direction.
[0011]
【The invention's effect】
According to the first, second, and third inventions, when the refrigerant is distributed and flowed to a plurality of cylinder groups (two banks), the refrigerant extraction position and the vehicle interior heating device are supplied to the cooling device. Since the refrigerant extraction position to the heater is assigned 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 balance between the plurality of cylinder groups is improved, The amount of heat released from the cylinder and the combustion chamber can be equalized between cylinder groups (between banks).
[0012]
Further, in the first, second, and third inventions, the refrigerant extraction path to the heater as the vehicle interior heating device is used as the refrigerant circulation path on the other cylinder group side. A sufficient coolant flow rate can be secured because the water flow resistance is smaller than when the merged portion is used as the take-out portion.
Further, according to the first aspect of the present invention, the refrigerant flowing through the refrigerant passage flows in the cylinder group row direction through the cylinder block, and then flows through the cylinder head in the cylinder group row direction opposite to the flow direction. Since the refrigerant extraction position of the heater as the vehicle interior heating device is the location where the flow of the cylinder block in the direction of the cylinder group is finished, the cylinder head is used as the vehicle interior heating device and the refrigerant heated to a high temperature by the cylinder block is used. Can be taken out.
[0013]
In addition, in a vehicle equipped with a large displacement engine as in the fourth aspect of the invention, the interior of the vehicle is wide, so when flowing the refrigerant to the heating device as the heating device in the vehicle interior, Resistance increases. Therefore, the effect of improving the flow rate balance between the cylinder groups (banks) is particularly remarkable as compared with the case of taking out the refrigerant from one cylinder group (bank) to the cooling device and the heater as the vehicle interior heating device. Become. Furthermore, since a sufficient refrigerant flow rate to the heater as the vehicle interior heating device can be ensured, when the temperature in the vehicle interior is increased, the temperature increase time can be shortened and a uniform temperature increase distribution can be obtained. .
[0014]
According to the fifth aspect of the present invention, the heat pipe that guides the high-temperature refrigerant to the passenger compartment can be shortened, so that the cost can be reduced and unnecessary heat loss can be suppressed, so that the temperature rise efficiency in the passenger compartment can be reduced. Can also be improved.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0016]
FIG. 1 is a cooling system diagram when the present invention is applied to a cooling device for a V-type engine employing a U-turn flow. The U-turn flow V-type engine 1 has two banks 2, 3, and each bank 2, 3 is composed of a cylinder block 4, 5 located at the bottom and a top cylinder head 6, 7.
[0017]
The U-turn flow V-type engine 1 is mounted vertically in front of a passenger compartment (not shown), and a radiator 18 (heat exchanger) is disposed further forward of the engine 1. Accordingly, although bank 2 is located on the left side in the figure, it is called “right bank”, and bank 3 is located on the right side in the figure but is called “left bank”.
[0018]
In each bank 2, 3, four passages (water jackets) 8A, 8B, 9A, 9B through which cooling water (refrigerant) flows independently are formed in the cylinder block and the cylinder head, and two cooling water passages in the right bank 2 are formed. 8A and 9A are connected rearward (upward in the figure) by a communication passage 10A, and the two cooling water passages 8B and 9B of the left bank 3 are also connected rearward by a communication passage 10B. In this case, both the water inlets 13A and 13B and the water outlets 15A and 15B are in front of the engine (downward in the drawing).
[0019]
A water pump 11 (feed pump) driven by a crankshaft (not shown) is attached to the front end portion of the engine 1. A pair of outlets 11a and 11b of the water pump 11 are connected to cooling water passages 8A and 8B in the cylinder blocks 4 and 5 through a pair of passages 12A and 12B.
[0020]
The cooling water passages 16A and 16B connected to the pair of outlets 15A and 15B are combined into a single passage 17, and this collective passage 17 is connected to an inlet 18a of a radiator 18 located in front of the vehicle, and an outlet 18b of the radiator 18 is The passage 19 is connected to the inlet 11 c of the water pump 11.
[0021]
In this way, the cooling water circulation path (refrigerant circulation path) on the right bank 2 side from the passage 12A, the cylinder block cooling water passage 8A, the communication passage 10A, the cylinder head cooling passage 9A, the passage 16A, the collecting passage 17, and the passage 19 is formed. Further, a cooling water circulation path (refrigerant circulation path) on the left bank 3 side is constituted by the passage 12B, the cylinder block cooling water passage 8B, the communication passage 10B, the cylinder head cooling passage 9B, the passage 16B, the collecting passage 17, and the passage 19. ing.
[0022]
Further, a thermostat 20 is provided in a passage 19 connecting the radiator 18 and the water pump 11. Reference numeral 22 denotes a reserve tank.
[0023]
In the drawing, 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 passes from the outlets 11a and 11b through the pair of passages 12A and 12B. The coolant flows into the cooling water passages 8A and 8B in the cylinder blocks 4 and 5 and flows through the cooling water passages 8A and 8B from the front of the vehicle to the rear of the vehicle to exchange heat with the cylinder blocks 4 and 5. Due to this heat exchange, the temperature of the cooling water rises and reaches the rear end of the engine. The cooling water that has reached the rear end of the engine then flows into the cooling water passages 9A and 9B in the cylinder head via the communication passages 10A and 10B. The cooling water passages 9A and 9B are then flowed from the rear of the vehicle to the front of the vehicle to exchange heat with the cylinder heads 6 and 7. Due to this heat exchange, the temperature of the cooling water further increases and reaches the front end of the engine, and this cooling water that has reached the front end of the engine is combined into one flow through the communication passages 16A and 16B. Guided to the radiator 18. Here, it is cooled by exchanging heat with the outside air.
[0024]
After cooling water flows from the front end of the engine in this direction to the rear end of the engine in this way, and then flows in the opposite direction from the rear end of the engine to the front end of the cylinder in the direction of the cylinder, this is called U-turn flow. According to this U-turn flow, the temperature management is easy because only two points of the cylinder blocks 4 and 5 and the cylinder heads 6 and 7 are required, and the cooling system can be simplified with a small number of parts. It has the advantage of being.
[0025]
Then, the cooling water cooled by the radiator 18 and having a low temperature is returned to the water pump 11 again.
[0026]
In this case, since the engine 1 is an engine having a large displacement (for example, 4.5 liters or more), a passage 21 that bypasses the radiator 18 from the passage 17 is provided. It is designed to circulate inside. Such a system is commonly referred to as a constant bypass.
[0027]
Further, when the temperature of the cooling water is low by the thermostat 20, the valve is throttled to reduce the flow rate of the cooling water flowing through the radiator 18. On the other hand, when the temperature of the cooling water becomes high, the valve is opened to turn off the radiator 18. The flow rate of the flowing cooling water is increased, whereby the temperature around the combustion chamber of the engine 1 is maintained at an appropriate value.
[0028]
On the other hand, an oil cooler 31 (cooling device) is provided for cooling the lubricating oil of the turbocharger and the like, and a heater 35 (heating device) is provided for heating a large vehicle interior. The cooling water to the oil cooler 31 is taken out from the cooling water passage 8B near the engine front end (near the first cylinder) of the left bank 3 in order to take out the cooling water before being heated by the engine 1. That is, the passage 32 is branched from the cooling water passage 8 </ b> B near the first cylinder of the left bank 3, and this branch passage 32 is connected to the inlet 31 a of the oil cooler 31. The cooling water whose temperature has been increased by performing heat exchange with the oil cooler 31 is returned to the upstream side of the water pump 11 from the outlet 31 b of the oil cooler 31 through the return passage 33. An EGR cooler (cooling EGR gas) can be considered as a replacement for the oil cooler 31.
[0029]
Here, in the case of a heater (heating device) as a vehicle interior heating device, it is better to take out the refrigerant at a high temperature (near the engine outlet) 15A in order to warm the vehicle interior. However, this portion is the most downstream side of the cooling water that has flowed through the engine 1 when viewed from the water pump 11, and therefore, there is a large amount of reduction in the cooling water flow rate due to the flow resistance. In this case, particularly when considering a vehicle equipped with an engine with a large displacement, the vehicle compartment is also widened, so that the coolant flow rate required for the heater 35 is increased corresponding to the size of the vehicle interior space. Therefore, even if the location where the coolant is at a high temperature, such as the vicinity of the engine outlet 15A, is the location where the coolant 35 is taken out to the heater 35, the flow rate of the coolant decreases due to the water flow resistance from the water pump 11 to the location where the coolant is taken out. There is a possibility that an unfavorable situation may occur in which the required flow rate to the heater 35 cannot be secured, the temperature distribution in the vehicle interior becomes uneven, and the wide vehicle interior space cannot be sufficiently heated.
[0030]
Therefore, the cooling water to the heater 35 as the vehicle interior heating device is taken out from the rear end portion of the cylinder head 6 of the right bank 2 that can ensure an appropriate cooling water temperature and flow rate. That is, the passage 36 is branched from the communication passage 10 </ b> A at the rear end of the cylinder head 6 of the right bank 2, and this branch passage 36 is connected to the inlet 35 a of the heater 35. The cooling water whose temperature has been reduced by performing heat exchange with the heater 35 is returned to the upstream side of the water pump 11 through the return passage 37 from the outlet 35 b of the heater 35.
[0031]
In this way, the cooling water takeout point to the oil cooler 31 is made from the cooling water passage 8B near the first cylinder of the left bank 3, and the cooling water takeout point to the heater 35 is the rear end of the cylinder head 6 in the right bank 2. Therefore, the flow rate balance of the cooling water flowing through the left and right banks 2 and 3 can be made uniform.
[0032]
The reason for determining the location for extracting the cooling water to the oil cooler 31 and the heater 35 is based on the experimental results shown in FIG. In FIG. 2, (1) to (3) at the bottom of FIG. 2 are (1) the communication passage 10B at the rear end of the left bank shown in FIG.
(2) A communication passage 10A at the rear end of the right bank,
(3) Meeting passage 17
It is the cooling water flow volume [L / min] which flows through each part. Of these, the case of (3), which is the most downstream from the water pump 11, has the largest water flow resistance, so it is the smallest of the three. In the case of (1) and (2), the water flow resistance is smaller than in the case of (3), so the flow rate is increased accordingly.
[0033]
In the case of the oil cooler 31, for cooling the oil, it must be taken out from a location where the cooling water is at a low temperature, that is, immediately downstream of the water pump 11. Actually, since the water pump 11 is fixed to the cylinder block, it cannot be taken out from the passage 12B. Therefore, it is taken out from the cooling water passage 8B near the first cylinder. At this time,
Oil cooler,
Cylinder block on the right bank (specifically, point (2) in FIG. 3),
Cylinder block on the left bank (specifically, point (1) in FIG. 3),
The result of measuring the flow rate flowing through is the case of (1) in the middle of FIG. Here, 51% and 49% of the numbers shown in parentheses are percentages when the total flow rate flowing through the cylinder blocks in the left and right banks is 100%. From the same number, when the cooling water to the oil cooler 31 was taken to the left bank, the balance between the left and right banks worked better, so the flow balance flowing through the cylinder blocks in the left and right banks was better than in the case of (2) in the middle stage. I understand that.
[0034]
In the case of (2) in the middle stage, the cooling water to the oil cooler 31 is taken out from the cooling water passage 8A near the front row cylinder in the right bank.
Oil cooler,
Cylinder block on the right bank (specifically, point (2) in FIG. 3),
Cylinder block on the left bank (specifically, point (1) in FIG. 3),
As a result of measuring the flow rate flowing through the right side, if the cooling water is extracted from the cooling water circulation path on the right bank side in this way, the flow rate balance flowing through the cylinder blocks in the left and right banks will be greatly disrupted.
[0035]
Next, in the case of the heater 35 as a vehicle interior heating device, for the purpose of warming the vehicle interior, it must be taken out from a location where the coolant is hot, that is, from the vicinity of the engine outlet. However, the downstream resistance of the water pump 11 increases the resistance to water flow, so that a sufficient flow rate cannot be secured, and the cooling water to the oil cooler 31 is taken out from the cooling water circulation path on the left bank side. In order to improve the flow rate balance, it is better to use the cooling water circulation path on the right bank side as the cooling water extraction point to the heater 35, so that the cooling water extraction point to the heater 35 is on the right bank side. The cooling water circulation path and the communication path 10A at the rear end of the right bank where the water flow resistance is smaller than the engine outlet. At this time,
Oil cooler,
heater,
Cylinder head in the right bank (specifically, point (4) in FIG. 3),
Left bank cylinder head (specifically, point (5) in FIG. 3),
The result of measuring the flow rate flowing through is the case of (2) in the upper part of FIG. 46% of the coolant flows in the cylinder head in the right bank and 54% in the cylinder head in the left bank. Here, 46% and 54% are percentages when the total flow rate flowing through the cylinder heads of the left and right banks is 100%. It can be seen that the flow balance flowing through the cylinder heads in the left and right banks is better than in the case of (1) above the same number.
[0036]
In the case of (1) in the upper stage, the cooling water to the heater 35 is taken out from the communication path 10B at the rear end of the left bank.
Oil cooler,
heater,
Cylinder head in the right bank (specifically, point (4) in FIG. 3),
Left bank cylinder head (specifically, point (5) in FIG. 3),
As a result of measuring the flow rate flowing through the left and right banks, when taking out not only the oil cooler 31 but also the coolant to the heater 35 from only the cooling water circulation path on the left bank side, the flow rate balance flowing through the cylinder heads 6 and 7 in the left and right banks. Will collapse greatly.
[0037]
The conclusion obtained by the experiment in this way is that the flow rate balance is substantially equal in the cylinder blocks 4 and 5 and the cylinder heads 6 and 7 of the left and right banks 2 and 3 in the case of (2) in the upper part of FIG. The flow rate flowing through 35 can be sufficiently ensured even when compared with other extraction methods.
[0038]
Returning to FIG. 1, reference numeral 40 denotes a throttle chamber, and warm cooling water is allowed 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 necessary, the passage 41 is branched from the collecting passage 17 where the hottest cooling water is obtained as in the prior art, and this branch passage 41 is connected to the throttle chamber 40. Is done. The cooling water whose temperature has been reduced by heat exchange in the throttle chamber 40 is returned to the upstream side of the water pump 11 through the return passage 42.
[0039]
Thus, 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 cooling water is taken out to the oil cooler 31 (cooling device). Since the location where the coolant is taken out to the heater 35 (heating device) is allocated to the left and right banks 2 and 3 so as not to be biased only to the coolant circulation path of one bank (cylinder group side), The flow rate balance is improved, and the amount of heat released from the cylinder and the combustion chamber can be equalized between the banks.
[0040]
Further, in the present embodiment, the cooling water circulation path (communication path 10A) before joining the two cooling water circulation paths instead of the two cooling water circulation paths is used as the cooling water extraction position to the heater 35. The water flow resistance can be made smaller than when the place where the roads merge (collecting passage 17) is taken as the take-out place. Therefore, a vehicle equipped with a large displacement engine has a large vehicle interior, and even when the heater 35 is used as an indoor heating device for this large vehicle compartment, a sufficient flow rate of cooling water can be secured. Even if the indoor space is large, the temperature rise time can be shortened and a uniform temperature distribution can be obtained in the passenger compartment.
[0041]
In addition, when the U-turn flow V-type engine 1 is mounted vertically in front of the passenger compartment and the radiator 18 (heat exchanger) is disposed further in front of the engine 1, the cooling water becomes the hottest. Is the front end of the engine having a coolant outlet (water outlet) from the engine 1, so that the location where the coolant is taken out to the heater 35 as a vehicle interior heating device is the front end of the engine from which high-temperature coolant is obtained. In this embodiment, the heat pipe for guiding the high-temperature cooling water to the passenger compartment located behind the engine becomes longer and the cost increases. However, according to the present embodiment, all the cylinder blocks flow in the cylinder row direction. The location (the communication passage 10A) is the rear end of the engine close to the passenger compartment, so that the heat pipe for guiding the high-temperature cooling water to the passenger compartment can be short, and the cost is low. Never to rise.
[0042]
In the embodiment, the description has been given of the case where the cooling water extraction point to the oil cooler 31 is the cooling water circulation path on the left bank side and the cooling water extraction point to the heater 35 is the cooling water circulation path on the right bank side. The location where the cooling water is taken out to the right side may be the cooling water circulation path on the right bank side, and the location where the cooling water is taken out to the heater 35 may be the cooling water circulation path on the left bank side.
[0043]
In the embodiment, the case where the present invention is applied to a U-turn flow V-type engine has been described. However, the present invention is not limited to this, and the present invention can also be applied to a so-called vertical flow or horizontal flow V-type engine. . The engine is not limited to the V type. A U-turn flow V-type engine may be mounted horizontally with respect to the vehicle.
[Brief description of the 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 flow rates at various parts depending on differences in the location where cooling water is extracted.
FIG. 3 is a cooling system diagram for showing the location where the cooling water used in FIG. 2 is taken out.
[Explanation of symbols]
2, 3 banks (cylinder group)
4, 5 Cylinder blocks 6, 7 Cylinder heads 8A, 8B Cooling water passages 9A, 9B in the cylinder block Cooling water passages 11 in the 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)

A plurality of cylinder groups are provided with independent refrigerant passages for each cylinder group, and the refrigerant flowing through the independent refrigerant passages flows through the cylinder block in the direction of the cylinder group row, and then the cylinder head is moved in the direction opposite to the flow direction. A U-turn flow that flows in the row direction, and includes the independent refrigerant passages, introduces the refrigerant from the feed pump into the independent refrigerant passages, and collects the refrigerants that have exited the independent refrigerant passages to form a heat exchanger. In an engine cooling device having a refrigerant circuit that returns to the feed pump after being led to
The refrigerant to the cooling device is taken out near the position where the flow to the cylinder block starts in the independent refrigerant passage on the side of one cylinder group downstream of the feed pump, and the refrigerant to the heater as the vehicle interior heating device is A cooling system for an engine, wherein a cylinder block is taken out at a position where the flow of the cylinder block in the direction of the cylinder group row is completed in the independent refrigerant passage on the cylinder group side.   The engine cooling apparatus according to claim 1, wherein the refrigerant to the throttle chamber is taken out from a passage through which the refrigerant exits the independent refrigerant passages. 3. When the engine is a V-type engine composed of 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 1. The engine cooling device according to any one of claims 1 to 3 , wherein an engine displacement is 4.5 liters or more . The engine cooling device according to any one of claims 1 to 4, wherein a refrigerant extraction position to the heater is on a side of a passenger compartment in a cylinder group row direction.

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