JP4288200B2 - Internal combustion engine with high and low temperature cooling system - Google Patents

Description

The present invention is mainly applied to a diesel engine for vehicles, industrial use, and power generation, and passes through a coolant and an oil cooler flowing through a coolant and a water jacket flowing through an intake air cooler of the engine (internal combustion engine). the cooling liquid flow, high cooling medium flowing, to circulate the heat exchanger disposed in the cooler cooling system high configured to cool by the cooling medium, the internal combustion institutions having cryogenic cooling system Related.

In diesel engines for vehicles, industrial use, power generation, etc., the engine water jacket, the supply air cooler that cools the engine supply air, and the cooling water of the oil cooler that cools the engine lubricating oil are guided to the radiator, The radiator is cooled by cooling air.
FIGS. 11-12 shows an example of the cooling device of such a diesel engine.
In the diesel engine cooling apparatus shown in FIG. 11, 100 is an engine (diesel engine), 60 is a radiator, 7 is a water jacket through which cooling water of a combustion chamber component such as a cylinder liner or cylinder head of the engine 100 flows. An engine jacket, 5 is an air cooler or air cooler for cooling the air supplied to the engine 100, 6 is an oil cooler for cooling the lubricating oil of the engine 100, 62 is a cooling water pump, and 64 is a thermostat.

  In such a diesel engine cooling apparatus, when the engine is started, the thermostat 64 closes the radiator inlet passage 63 on the radiator 60 side and opens the bypass passage 66 leading to the radiator outlet passage 16. In this state, the cooling water pumped by the cooling water pump 62 enters the oil cooler 6, where the oil introduced from the oil inlet pipe 18 is cooled in the oil cooler 6 (19 is an oil outlet pipe), and the cooling water passage 61. After passing through the engine jacket 7, the combustion chamber components such as the cylinder liner and the cylinder head are cooled in the engine jacket 7, and then returned to the thermostat 64.

When the engine load increases and the temperature of the cooling water exceeds the valve opening temperature of the thermostat 64, the thermostat 64 opens the radiator inlet passage 63. In this state, the cooling water pumped by the cooling water pump 62 enters the oil cooler 6, cools the oil introduced from the oil inlet pipe 18 in the oil cooler 6, and passes through the cooling water passage 61 to the engine jacket 7. The engine jacket 7 cools the combustion chamber components such as the cylinder liner and the cylinder head, and then enters the radiator 60 through the thermostat 64 and the radiator inlet passage 63. The radiator 60 cools by the cooling air, and the radiator It returns to the cooling water pump 62 through the outlet passage 16.
On the other hand, the air supplied from the supercharger (not shown) through the air supply passage 30 is cooled by the air cooler 5 with a cooling medium such as air and is sent to the engine 100 through the air supply passage 31.

  12 is a diesel engine cooling device disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 6-229241). In the figure, 100 is an engine (diesel engine), 60 is a radiator, and 7 is an engine 100. A water jacket, that is, an engine jacket, through which cooling water of a combustion chamber component such as a cylinder liner and a cylinder head flows, 5 is a supply air cooler, that is, an air cooler, that cools supply air to the engine 100, and 6 is provided upstream of the engine jacket. An oil cooler that cools the lubricating oil of the engine 100, 62 is a cooling water pump, and 64 is a thermostat.

In such a diesel engine cooling apparatus, when the engine is started, the thermostat 64 closes the radiator inlet passage 63 on the radiator 60 side and opens the bypass passage 66 leading to the radiator outlet passage 16. In this state, the cooling water pumped by the cooling water pump 62 enters the oil cooler 6 to cool the oil introduced from the oil inlet pipe 18 in the oil cooler 6 (19 is an oil outlet pipe), and the cooling water passage 67. And enters the engine jacket 7 where the combustion chamber components such as the cylinder liner and the cylinder head are cooled.
On the other hand, the cooling water branched at the outlet of the cooling water pump 62 enters the air cooler 5 where the air supply introduced from the supercharger (not shown) through the air supply passage 30 is cooled. The cooling water from the engine jacket 7 is merged in the passage 68 and returned to the thermostat 64 through the cooling water passage 69.

When the engine load increases and the temperature of the cooling water exceeds the valve opening temperature of the thermostat 64, the thermostat 64 opens the radiator inlet passage 63. In this state, the cooling water pumped by the cooling water pump 62 enters the oil cooler 6, cools the oil introduced from the oil inlet pipe 18 in the oil cooler 6, and passes through the cooling water passage 67 to the engine jacket 7. Then, the engine jacket 7 cools the combustion chamber components such as the cylinder liner and the cylinder head.
On the other hand, the cooling water branched at the outlet of the cooling water pump 62 enters the air cooler 5 where the air supply introduced from the supercharger (not shown) through the air supply passage 30 is cooled. The coolant merges with the cooling water from the engine jacket 7 through the passage 68, enters the radiator 60 through the cooling water passage 69 through the thermostat 64 and the radiator inlet passage 63, and is cooled by the cooling air in the radiator 60. Returned to pump 62.

JP-A-6-229241

However, the prior art shown in FIGS. 11 to 12 has the following problems.
In the prior art shown in FIG. 11, in order to control the supply air temperature, a device for controlling the flow rate and temperature of the cooling medium in the air cooler 5 must be prepared separately. When the engine is started at an extremely low temperature, the temperature of the air that is the cooling medium of the air cooler 5 is low, so that overcooling of the supply air occurs in the air cooler 5, and the supply air temperature falls below the required temperature. For this reason, the ignitability of fuel in the engine 100 is deteriorated, and white smoke is easily generated in the exhaust gas.

In the prior art shown in FIG. 12, the cooling water system including one radiator 60 circulates the cooling water of the engine jacket 7, the air cooler 5, and the oil cooler 6. When the air supply temperature is lowered by increasing the cooling degree in the air cooler 5, the temperature of the engine jacket 7 in the same cooling water system as the air cooler 5 is excessively lowered to reduce the combustion performance. At the same time, the capacity of the radiator 60 increases and the apparatus becomes larger.
And so on.

In view of the problems of the prior art, the present invention can quickly increase the coolant temperature of the charge air cooler, the oil cooler, and the water jacket when the engine is started to maintain good ignitability and improve combustion performance. thereby avoiding the discharge of white smoke in the exhaust gas, and an object thereof is to provide an internal combustion institutions capable of downsizing the volume of the heat exchanger.

SUMMARY OF THE INVENTION The present invention achieves such an object, and includes cooling liquid flowing through an intake air cooler (air cooler) for cooling an intake air of an engine (internal combustion engine) and cooling flowing through a water jacket (engine jacket) of the engine. In an internal combustion engine configured to circulate a heat exchanger through which a cooling medium flows and to cool the liquid by the cooling medium, two heat exchangers are provided, and one of the low-temperature side heat exchanger and at least the above-described heat exchanger A low-temperature side cooling system that forms a circulation path for circulating the cooling liquid between the supply air cooler, and a circulation path for circulating the cooling liquid between the other high-temperature side heat exchanger and at least the water jacket. An oil cooler configured to cool the engine lubricating oil (oil) is disposed in parallel with the supply air cooler in the circulation path of the low temperature side cooling system, In the coolant outlet passage of the cooler A supply air cooler side bypass passage that bypasses the low temperature side heat exchanger and is connected to the low temperature side heat exchanger outlet, and a supply air cooler side thermostat that opens and closes the supply air cooler side bypass passage, An oil cooler side thermostat that bypasses the low temperature side heat exchanger and is connected to the low temperature side heat exchanger outlet and an oil cooler side thermostat that opens and closes the oil cooler side bypass passage in the coolant outlet passage of the oil cooler. It is provided .

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  With this configuration, by changing the set temperatures of the supply air cooler-side thermostat and the oil cooler-side thermostat, the flow of the coolant is changed so as to obtain the required heat dissipation in the supply air cooler and the oil cooler. The temperature can be adjusted freely, and the supply air temperature at the outlet of the intake air cooler, that is, the engine inlet, and the oil temperature at the oil cooler outlet, that is, the oil temperature at the engine inlet can be controlled to a required temperature.

Moreover, in this invention, the first configuration of the low temperature side heat exchanger and the high temperature side heat exchanger includes a low temperature side radiator and a high temperature side radiator that cool the coolant with air constituting a cooling medium.
If the low-temperature side radiator and the high-temperature side radiator are arranged in parallel to the flow direction of the cooling air from the cooling fan that supplies cooling air to them, the pressure loss of the low-temperature side radiator and the high-temperature side radiator is reduced. Can be small.
On the other hand, if the low-temperature side radiator and the high-temperature side radiator are arranged in series with respect to the flow direction of the cooling air from the cooling fan, the front area of the radiator can be reduced, and both the radiators can have a compact structure. Can do.

In this invention, the second configuration of the low-temperature side heat exchanger and the high-temperature side heat exchanger is configured to cool the coolant by exchanging heat between the fresh water or sea water that constitutes the cooling medium and the coolant. It consists of a heat extractor.
With this configuration, since fresh water or seawater is used as a cooling medium, heat exchange efficiency is higher than that of a radiator using air as a cooling medium, and the heat exchanger can be downsized and applied to a wide range of engines including marine engines. It becomes possible.

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According to the present invention, two heat exchangers, a low temperature side heat exchanger that cools the coolant of the charge air cooler and the oil cooler, and a high temperature side heat exchanger that cools the coolant of the water jacket, When the engine is started, the coolant temperature of the charge air cooler and the oil cooler and the coolant temperature of the water jacket can be quickly adjusted by organically using the thermostat settings during low-load operation, light-load operation, and high-load operation. It is possible to raise the temperature around the combustion chamber quickly, maintain good ignitability, avoid emission of white smoke in the exhaust gas, and also raise the lubricating oil temperature quickly. Can do.
In addition, during light load operation where the heat load is small and cooling of the water jacket coolant is not necessarily required, it is possible to stop the use of the high temperature side heat exchanger. The capacity of the high-temperature side heat exchanger can be reduced as compared with the conventional one that has been operated.
Further, the temperature difference between the high temperature side heat exchanger and the cooling medium becomes large, and the heat exchange efficiency can be increased and the size can be reduced. Therefore, the high temperature side heat exchanger as a whole can be reduced in size compared to the conventional integrated heat exchanger.

  Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this example are not intended to limit the scope of the present invention only to specific examples unless otherwise specified. Only.

Figure 1 is system diagram of a cooling device for a diesel engine according to the first exemplary embodiment of the present invention, Figure 2 is Figure 1 corresponds diagram showing the second reference example, FIG. 3 FIG. 1 corresponds diagram showing a third reference example, FIG. 4 Figure 1 corresponds diagram illustrating an embodiment of the present invention, FIG. 5 FIG. 1 corresponds diagram showing a fourth reference example, FIG. 6 is a diagram 1 corresponding view showing a fifth embodiment. FIG. 7 is a diagram corresponding to FIG. 1 showing a sixth reference example , and FIG. 8 is a control block diagram of the sixth reference example . Figure 9 is a configuration diagram showing a first example of an arrangement of a radiator before you施例, FIG. 10 is a configuration diagram showing a second example of the arrangement of the radiator before you施例.

(Reference Example 1)
In FIG. 1 showing a first reference example of the present invention, reference numeral 100 denotes an engine (diesel engine), 7 denotes a water jacket, that is, an engine jacket, through which cooling water of a combustion chamber constituent member such as a cylinder liner or cylinder head of the engine 100 flows. Reference numeral 5 denotes a supply air cooler, that is, an air cooler for cooling supply air to the engine 100, and reference numeral 6 denotes an oil cooler for cooling the lubricating oil of the engine 100.
In the present invention, the radiator for cooling the cooling water flowing through the engine jacket 7, the air cooler 5 and the oil cooler 6 is composed of two radiators including a low temperature side radiator 1 and a high temperature side radiator 2. .

Reference numeral 14 denotes a radiator outlet passage connected to the cooling water outlet of the low temperature side radiator 1, and a low temperature side water pump 8 is disposed in the radiator outlet passage 14. The air cooler 5 and the oil cooler 6 are arranged in parallel to the outlet of the low temperature side water pump 8.
That is, the outlet of the low temperature side water pump 8 is branched into two cooling water passages, one cooling water passage 22 is connected to the inlet of the oil cooler 6, and the other cooling water passage 13 is connected to the inlet of the air cooler 5. It is connected.
Reference numeral 11 denotes a cooling water junction passage where the cooling water outlet passage of the air cooler 5 and the cooling water outlet passage of the oil cooler 6 merge.

3 is a low temperature side thermostat, 10 is a low temperature side bypass passage connecting the bypass outlet of the low temperature side thermostat and the radiator outlet passage 14, and 12 is an outlet of the low temperature side thermostat and a cooling water inlet of the low temperature side radiator 1. It is a radiator inlet passage to be connected.
18 is an oil inlet passage of the oil cooler 6, 19 is an oil outlet passage connected to a main gallery (not shown), 20 is an oil side thermostat disposed in the oil inlet passage 18, and 21 is a bypass side of the oil side thermostat. An oil bypass passage connecting an outlet and the oil outlet passage.
The low temperature side cooling system is configured as described above.

Reference numeral 16 denotes a radiator outlet passage connected to the cooling water outlet of the high temperature side radiator 2, and a high temperature side water pump 9 is disposed in the radiator outlet passage 16. The engine jacket 7 is disposed at the outlet of the high temperature side water pump 9.
4 is a high temperature side thermostat, 15 is a high temperature side bypass passage connecting the bypass outlet of the high temperature side thermostat 4 and the radiator outlet passage 16, and 32 is an outlet of the high temperature side thermostat 4 and a cooling water inlet of the high temperature side radiator 2. Is a radiator inlet passage connecting the two. A cooling water passage 17 connects the cooling water outlet of the engine jacket 7 and the cooling water inlet of the high temperature side thermostat 4.
The high temperature side cooling system is configured as described above.
Here, the valve opening temperature of the low temperature side thermostat 3 is set lower than the valve opening temperature of the high temperature side thermostat 4.

In the first reference example , when the engine is started, the low-temperature side thermostat 3 closes the radiator inlet passage 12 on the low-temperature side radiator 1 side and opens the low-temperature side bypass passage 10 that leads to the radiator outlet passage 14. Further, the high temperature side thermostat 4 closes the radiator inlet passage 32 on the high temperature side radiator 2 side and opens the high temperature side bypass passage 15 communicating with the radiator outlet passage 16.
In this state, the cooling water pumped by the low-temperature water pump 8 enters the oil cooler 6 through the cooling water passage 22 and enters the air cooler 5 through the cooling water passage 13. The oil cooler 6 cools oil introduced from an oil pump (not shown) through an oil inlet pipe 18, and the air cooler 5 supplies a supply air introduced from a supercharger (not shown) through an air supply passage 30. Cool your mind.
Then, the cooling water exiting the oil cooler 6 and the air cooler 5 enters the low temperature side thermostat 3 through the cooling water junction passage 11. Since the low temperature side thermostat 3 closes the radiator inlet passage 12 on the low temperature side radiator 1 and opens the low temperature side bypass passage 10 as described above, the cooling water flows as shown by the arrow A in the figure, It is circulated to the suction port of the side water pump 8.

On the other hand, the cooling water pumped by the high temperature side water pump 9 enters the engine jacket 7 through the cooling water passage 022. In the engine jacket 7, combustion chamber components such as a cylinder liner and a cylinder head are cooled.
Then, the cooling water exiting the engine jacket 7 passes through the cooling water passage 17 and enters the high temperature side thermostat 4. Since the high temperature side thermostat 4 closes the radiator inlet passage 32 on the high temperature side radiator 2 side and opens the high temperature side bypass passage 15 as described above, the cooling water flows as indicated by the arrow B in the figure, It is circulated to the suction port of the side water pump 9.

According to the reference example , as described above, when the engine 100 is started, both the low temperature side thermostat 3 on the low temperature side radiator 1 side and the high temperature side thermostat 4 on the high temperature side radiator 2 side are closed, and the low temperature side radiator 1 is thus closed. And the flow of the cooling water to both the high temperature side radiator 2 is cut off, and the cooling water of the air cooler 5, the oil cooler 6 and the cooling water of the engine jacket 7 are circulated to the engine 100 side without being cooled.
Therefore, when the engine 100 is started, the temperature of the cooling water of the air cooler 5 and the oil cooler 6 and the temperature of the cooling water of the air cooler 5 rise quickly, and the temperature rise around the combustion chamber such as the cylinder liner, cylinder head, piston, etc. The ignitability becomes better.
As a result, the discharge of white smoke in the exhaust gas is avoided, and the cooling water of the oil cooler 6 is circulated without cooling, so that the lubricating oil temperature rises quickly and the oil is supplied to the required lubricating portion. This is done smoothly and the frictional horsepower is reduced.

  During the light load operation of the engine, if the temperature of the cooling water flowing through the low temperature side thermostat 3 and the high temperature side thermostat 4 exceeds the set temperature of the low temperature side thermostat 3 and the high temperature side thermostat 4, the low temperature side thermostat 3 and the high temperature side Thermostat 4 begins to open. In this state, a part of the cooling water that has passed through the low temperature side thermostat 3 flows as indicated by an arrow C in the figure, is sent to the low temperature side radiator 1 and cooled, and then is returned to the suction port of the low temperature side water pump 8. At the same time, most of the remaining cooling water passes through the low temperature side bypass passage 10 and is returned to the suction port of the low temperature side water pump 8 to be merged with the cooling water from the low temperature side radiator 1. Therefore, the temperature of the low temperature side cooling system is maintained at a constant temperature where the two low temperature side cooling waters are mixed.

On the other hand, a part of the cooling water that has passed through the high temperature side thermostat 43 flows as indicated by an arrow D in the figure, is sent to the high temperature side radiator 2 and is cooled, and is then returned to the suction port of the high temperature side water pump 9. At the same time, most of the remaining cooling water passes through the high temperature side bypass passage 15 and is returned to the suction port of the high temperature side water pump 9 to be merged with the cooling water from the high temperature side radiator 2.
Accordingly, the cooling water temperature of the high temperature side cooling system is maintained at a constant temperature higher than the cooling water temperature of the low temperature side cooling system by mixing the two high temperature side cooling waters.

  Therefore, as described above, since the set temperature of the high temperature side thermostat 4 is higher than the set temperature of the low temperature side thermostat 3, the cooling water temperature on the engine jacket 7 side is set to the air cooler 5 and the oil cooler 6 at a light load of the engine. The cooling water temperature can be raised to a certain extent, thereby avoiding overcooling around the combustion chamber, and by raising the temperature around the combustion chamber, a good combustion state can be maintained.

During high load operation exceeding the constant load, the temperature of the cooling water flowing through the low temperature side thermostat 3 and the high temperature side thermostat 4 greatly exceeds the set temperature of the low temperature side thermostat 3 and the high temperature side thermostat 4, and the low temperature side thermostat 3 and the high temperature side thermostat 4 are fully opened.
In this state, the entire amount of cooling water that has passed through the low temperature side thermostat 3 flows as indicated by an arrow C in the figure, is sent to the low temperature side radiator 1 and is cooled, and then is returned to the suction port of the low temperature side water pump 8. Therefore, the temperature of the low temperature side cooling system is maintained at a constant temperature determined by the degree of cooling in the low temperature side radiator 1 and the load of the engine 100.
On the other hand, the total amount of the cooling water that has passed through the high temperature side thermostat 43 flows as indicated by an arrow D in the figure, and is sent to the high temperature side radiator 2 to be cooled and then returned to the suction port of the high temperature side water pump 9.
Accordingly, the temperature of the high temperature side cooling system is maintained at a constant temperature determined by the degree of cooling in the high temperature side radiator 2 and the load of the engine 100.

Further, according to the reference example , when starting the engine at a very low temperature in a cold region or the like, the low temperature side thermostat 3 is closed to cool the cooling water of the oil cooler 6 and the cooling water to the low temperature side radiator 1 is cooled. In addition to interrupting the flow and circulating the cooling water to the engine 100 without cooling, the oil thermostat 20 is closed and the oil flows to the oil bypass passage 21 to flow the oil to the oil cooler 6. By shutting off the oil temperature, the oil temperature can be rapidly increased. As a result, the normal viscosity and fluidity of the oil can be maintained even at extremely low temperatures.

Therefore, according to this reference example , the two radiators of the low-temperature side radiator 1 that cools the cooling water of the air cooler 5 and the oil cooler 6 and the high-temperature side radiator 2 that cools the cooling water of the engine jacket 7 are When the engine 100 is started, the cooling water and the engine of the air cooler 5 and the oil cooler 6 are used by organically using the low temperature side thermostat 3 and the high temperature side thermostat 4 in the light load operation and the high load operation. The temperature of the jacket 7 cooling water can be quickly raised, the temperature around the combustion chamber of the engine 100 can be quickly raised to maintain good ignitability, and discharge of white smoke in the exhaust gas can be avoided. In addition, the lubricating oil temperature can be quickly increased.
In addition, the use of the high-temperature side radiator 2 can be stopped during light load operation where the heat load is small and cooling of the cooling water for the engine jacket 7 is not necessarily required. Therefore, the radiator is also operated during light load operation. Compared with the conventional one, the capacity of the high-temperature side radiator 2 can be reduced.
In addition, since the high temperature side heat exchanger such as the high temperature side radiator 2 has a large temperature difference from the cooling medium and can reduce the heat exchange efficiency and reduce the size, as a whole, compared with the conventional integrated heat exchanger. It can be downsized.

(Second reference example)
In the second reference example shown in FIG. 2, the oil-side thermostat 20 disposed in the oil inlet passage 18, the bypass-side outlet of the oil-side thermostat 20, and the oil outlet are compared to the first reference example of FIG. 1. The oil bypass passage 21 that connects the passage 19 is removed.
Other configurations are the same as those of the first reference example , and the same members are denoted by the same reference numerals.
In the second reference example , the oil-side thermostat 20 and the oil bypass passage 21 are removed from the first reference example , so that the oil temperature after the start-up can be rapidly increased as in an engine used in a cold region or the like. It is suitable for an engine that does not need to be raised, and has a simpler structure and lower cost than the first reference example .

In the second to sixth reference examples and the embodiments of the present invention described below, the oil side thermostat 20 disposed in the oil inlet passage 18 and the oil side thermostat 20 are similar to the second reference example . The oil bypass passage 21 that connects the bypass side outlet and the oil outlet passage 19 is removed, and the effect of this is the same as in the case of the second reference example .

(Third reference example)
In the third reference example shown in FIG. 3, in the low temperature side cooling system, the air cooler 5 is connected upstream of the low temperature side water pump 8 outlet and the oil cooler 6 is connected in series downstream of the air cooler 5. Yes.
In the third reference example , the low-temperature cooling water from the low-temperature side radiator 1 is passed through the air cooler 5 having a low temperature level, and the supply air is cooled by the air cooler 5 to raise the temperature. Thereafter, since the oil is cooled through the oil cooler 6 having a temperature level higher than that of the air cooler 5, the cooling efficiency of the air cooler 5 and the oil cooler 6 is increased, and the capacity of the air cooler 5 or the oil cooler 6 can be reduced.
In the third reference example , by configuring as described above, the flow rate of the cooling water flowing through the air cooler 5 and the oil cooler 6 can be increased, and the heat exchange efficiency in the air cooler 5 and the oil cooler 6 is increased. The air cooler 5 or the oil cooler 6 can be reduced in size.
In the third reference example , the oil-side thermostat 20 disposed in the oil inlet passage 18, the bypass-side outlet of the oil-side thermostat 20 and the oil outlet passage 19 are different from the first reference example . The oil bypass passage 21 to be connected is removed.
Other configurations are the same as those of the first reference example , and the same members are denoted by the same reference numerals.

(Example)
FIG. 4 shows an embodiment of the present invention. In FIG. 4, an air cooler bypass passage 10 a that bypasses the low temperature side radiator 1 to the cooling water passage 35 on the outlet side of the air cooler 5 and is connected to the low temperature side radiator outlet passage 14. And an air cooler side thermostat 3b for opening and closing the air cooler side bypass passage 10a,
The cooling water passage 34 on the oil cooler 6 outlet side is provided independently of the cooling water passage 35 on the outlet side of the air cooler 5, and joins the cooling water passage 34 on the outlet side of the oil cooler 6 to the air cooler bypass passage 10 a. An oil cooler side bypass passage 36 and an oil cooler side thermostat 3a for opening and closing the oil cooler side bypass passage 36 are provided.
By configuring in this way, the flow of the cooling water is changed so that the required heat dissipation amount in the air cooler 5 and the oil cooler 6 can be obtained by changing the set temperature of the air cooler side thermostat 3b and the oil cooler side thermostat 3a. The air cooler 5 outlet, that is, the supply air temperature at the engine inlet, and the oil temperature at the oil cooler 6 outlet, that is, the oil temperature at the engine inlet, can be controlled to the required temperatures.

In the actual施例that written, the similar to the second to third reference example, the relative first reference example, an oil-side thermostat 20 disposed in the oil inlet passage 18, the oil side thermostat An oil bypass passage 21 that connects the bypass outlet 20 and the oil outlet passage 19 is removed.
Other configurations are the same as those of the first reference example , and the same members are denoted by the same reference numerals.

(4th reference example)
In the fourth reference example shown in FIG. 5, instead of the low temperature side radiator 1 and the high temperature side radiator 2 in the first to third reference examples , fresh water or sea water constituting the cooling medium and the cooling water are subjected to heat exchange. By doing so, a low temperature side heat extractor 40 and a high temperature side heat extract changer 41 for cooling the cooling water are provided.
According to the fourth reference example , since fresh water or seawater is used as the cooling medium, the heat exchange efficiency is higher than the radiators using the air as the cooling medium (the low-temperature side radiator 1 and the high-temperature side radiator 2), and the heat exchanger The (heat exchanger 40 and the high temperature side heat exchanger 41) can be reduced in size and applied to a wide range of engines including marine engines.
Further, it is not necessary to circulate external cooling water (seawater or the like) directly to the air cooler 5, and it is possible to eliminate special considerations such as using a corrosion-resistant material on the air cooler 5 side.
In the fourth reference example , the oil side thermostat 20 disposed in the oil inlet passage 18 and the bypass outlet of the oil side thermostat 20 and the oil outlet passage 19 are connected to the first reference example . The oil bypass passage 21 is removed.
Other configurations are the same as those of the first reference example , and the same members are denoted by the same reference numerals.

(5th reference example)
In the fifth reference example shown in FIG. 6, the oil cooler 6 is disposed in series with the engine jacket 7 upstream of the engine jacket 7 in the high-temperature side cooling system including the high-temperature side radiator 2. In the low temperature side cooling system provided with the low temperature side radiator 1, only the air cooler 5 is installed.
If comprised in this way, since the said oil cooler 6 was arrange | positioned in series with the engine jacket 7 in the upstream of this engine jacket 7, the cooling water cooled with the high temperature side radiator 2 will cool the oil cooler 6. As a result, the temperature can be raised to an appropriate temperature for cooling the engine jacket 7, the cooling efficiency of the oil cooler 6 and the engine jacket 7 is improved, and the capacity of the low-temperature side radiator 1 for cooling the cooling water for the air cooler 5 is reduced. it can.
Moreover, in this 5th reference example , the oil side thermostat 20 and the oil bypass passage 21 are removed with respect to the said 1st reference example similarly to the said 2nd- 4th reference example .
Other configurations are the same as those of the first reference example , and the same members are denoted by the same reference numerals.

(Sixth reference example)
In the sixth reference example shown in FIGS. 7 to 8, the low-temperature side water pump (A) 8 provided in the cooling water passage 14 from the low-temperature side radiator 1 and the cooling water passage 16 from the high-temperature side radiator 2. The pump drive motor (A) and the pump drive motor (B) that respectively drive the high-temperature side water pump (B) 9 provided in the controller are configured as variable speed motors, and a controller 54 to which detection signals from the following sensors are input. Thus, the rotational speed of the pump drive motor (A) and the pump drive motor (B) is controlled.
52 is a supply air temperature sensor for detecting the supply air temperature at the outlet of the air cooler 5, 51 is an oil temperature sensor for detecting the oil temperature (oil temperature) at the outlet of the oil cooler 6, and 53 is the fresh water temperature ( A water temperature sensor for detecting a water temperature), a supply air temperature detection value from the supply air temperature sensor 52, an oil temperature detection value from the oil temperature sensor 51, and a water temperature detection value from the water temperature sensor 53 are respectively sent to the controller 54. It is designed to be entered.
In the sixth reference example , as in the second to fifth reference examples , the oil-side thermostat 20 and the oil bypass passage 21 are removed from the first reference example .
Other configurations are the same as those of the first reference example , and the same members are denoted by the same reference numerals.

Next, the operation of the sixth reference example will be described based on the block diagram of FIG.
The supply air temperature detection value from the supply air temperature sensor 52 is input to the supply air temperature determination unit 82 of the controller 54, and the oil temperature detection value from the oil temperature sensor 51 is input to the oil temperature determination unit 84 of the controller 54. The detected water temperature value from the water temperature sensor 53 is input to the water temperature determination unit 80 of the controller 54.
Reference numeral 81 denotes a supply air temperature setting unit, as shown in FIG. 8B, in which the relationship between the target value of the supply air temperature and the rotation speed of the water pump (A) 8 (pump (A) rotation speed) is set. ing. That is, as shown in FIG. 8B, the supply air temperature setting unit 81 increases the pump (A) rotation speed as the target value of the supply air temperature set according to the engine operating conditions decreases, and supplies the air cooler 5 to the air cooler 5. It is set to increase the amount of cooling water.

83 is an oil temperature setting unit, and as shown in FIG. 8B, the relationship between the target oil temperature at the outlet of the oil cooler 6 and the rotation speed of the water pump (A) 8 (pump (A) rotation speed). Is set. That is, as shown in FIG. 8 (B), the oil temperature setting unit 83 increases the pump (A) rotation speed as the oil temperature target value set according to the engine operating conditions decreases, It is set to increase the amount of cooling water.
85 is a water temperature setting unit, and as shown in FIG. 8C, the relationship between the target value of the water temperature at the outlet of the engine jacket 7 and the rotation speed of the water pump (B) 9 (pump (B) rotation speed) is set. Has been. That is, as shown in FIG. 8C, the water temperature setting unit 85 increases the pump (B) rotation speed as the target value of the water temperature set according to the engine operating conditions decreases, and the amount of cooling water to the engine jacket 7 is increased. Is set to increase.

In the supply air temperature determination unit 82, the supply air temperature detection value is compared with the target value of the supply air temperature shown in FIG. The temperature deviation is calculated and input to the pump (A) rotation speed calculation unit 87. The oil temperature determination unit 84 compares the detected oil temperature value with the target oil temperature value shown in FIG. 8B set in the oil temperature setting unit 84, and calculates the oil temperature deviation. This is calculated and input to the pump (A) rotation speed calculation unit 87.
The pump (A) rotation speed calculation unit 87 calculates the pump rotation speed adjustment amount of the water pump (A) 8 based on the supply air temperature deviation and the oil temperature deviation, and outputs it to the pump drive motor (A) 55. . The pump drive motor (A) 55 adjusts the pump rotational speed of the water pump (A) 8 by the pump rotational speed adjustment amount.
Thereby, the water pump (A) 8 is operated at a rotational speed such that the supply air temperature and the oil temperature become the target values.

Further, the water temperature determination unit 86 compares the detected water temperature value with the target water temperature value shown in FIG. 8C set in the water temperature setting unit 85, calculates the water temperature deviation, and calculates the pump ( B) Input to the rotation speed calculation unit 87. Further, the water temperature determination unit 86 compares the detected water temperature value with the target water temperature value shown in FIG. 8C set in the setting unit 85, calculates the water temperature deviation, and calculates the pump (B ) Input to the rotation speed calculation unit 88.
The pump (B) rotational speed calculation unit 88 calculates the pump rotational speed adjustment amount of the water pump (B) 8 based on the water temperature deviation and outputs it to the pump drive motor (B) 56. The pump drive motor (B) 56 adjusts the pump rotational speed of the water pump (B) 9 by the pump rotational speed adjustment amount.
Thereby, the water pump (B) 9 is operated at a rotation speed such that the water temperature becomes the target value.

According to the sixth reference example , the supply air temperature, the oil temperature, and the water temperature are detected, the detected values of the supply air temperature and the oil temperature are compared with these target values, and the supply air temperature is based on the comparison result. In addition, the rotation speed of the water pump (A) 8 for conveying the cooling water in the low temperature side cooling system is controlled so that the oil temperature becomes the target value, and the detected value of the water temperature and the target value thereof are compared and compared. Since the rotation speed of the water pump (B) 9 in the high temperature side cooling system is controlled so that the water temperature becomes the target value based on the result, the temperatures of the air cooler 5, the oil cooler 6 and the engine jacket 7 are set to the target temperature with high accuracy. It becomes possible to control.

Next, FIG. 9-10 shows an example of an arrangement of the low-temperature side radiator 1 and the high-temperature side radiator 2 before you施例.
In the arrangement example of FIG. 9, the flow direction (arrow) of the cooling air from the radiator fan 101 that drives the low temperature side radiator 1 and the high temperature side radiator 2 directly to the engine 100 and supplies the cooling air to the radiators 1 and 2. Are arranged in parallel.
If it arrange | positions in this way, the pressure loss of the low temperature side radiator 1 and the high temperature side radiator 2 can be made small.

In the arrangement example of FIG. 10, the flow direction (arrow) of the cooling air from the radiator fan 101 that drives the low-temperature side radiator 1 and the high-temperature side radiator 2 directly to the engine 100 and supplies the cooling air to the radiators 1 and 2. Are arranged in series.
If arranged in this way, the front surface area of the radiator can be reduced, and both the radiators 1 and 2 can be made compact.

  According to the present invention, when the engine is started, the coolant temperature of the charge air cooler, the oil cooler, and the water jacket can be quickly raised, and the combustion performance can be improved while maintaining good ignitability and the exhaust gas. An internal combustion engine capable of avoiding the discharge of white smoke therein and reducing the capacity of a heat exchanger and an operation method thereof.

It is a systematic diagram of the cooling device of the diesel engine which concerns on a 1st reference example . It is a figure corresponding to FIG. 1 which shows a 2nd reference example . It is a figure corresponding to FIG. 1 which shows a 3rd reference example . It is a figure corresponding to FIG. 1 which shows the Example of this invention . It is a figure corresponding to FIG. 1 which shows a 4th reference example . It is a figure corresponding to FIG. 1 which shows a 5th reference example . It is a figure corresponding to FIG. 1 which shows a 6th reference example . It is a control block diagram in the sixth reference example . It is a block diagram showing a first example of an arrangement of a radiator before you施例. It is a block diagram showing a second example of the arrangement of the radiator before you施例. It is a figure corresponding to FIG. 1 which shows the 1st example of a prior art. It is a figure corresponding to FIG. 1 which shows the 2nd example of a prior art.

DESCRIPTION OF SYMBOLS 100 Engine 101 Radiator fan 1 Low temperature side radiator 2 High temperature side radiator 3 Low temperature side thermostat 3a Oil cooler side thermostat 3b Air cooler side thermostat 4 High temperature side thermostat 5 Air cooler 6 Oil cooler 7 Engine jacket 8 Water pump (A) (low temperature side)
9 Water pump (B) (High temperature side)
20 Oil side thermostat 40 Low temperature side heat exchanger 41 High temperature side heat extractor 51 Oil temperature sensor 52 Air supply temperature sensor 53 Water temperature sensor 54 Controller 55 Pump drive motor (A)
56 Pump drive motor (B)

Claims (5)

Heat exchange in which the cooling medium flows through the coolant flowing through the supply air cooler (air cooler) for cooling the supply air of the engine (internal combustion engine) and the coolant flowing through the water jacket (engine jacket) of the engine An internal combustion engine configured to circulate a vessel and cool by the cooling medium,
Two heat exchangers are provided, a low temperature side cooling system in which a circulation path for circulating the coolant between at least one low temperature side heat exchanger and at least the charge air cooler is formed, and the other high temperature side heat exchange A high-temperature side cooling system that forms a circulation path through which the cooling liquid circulates between the vessel and at least the water jacket,
An oil cooler that cools the engine lubricating oil (oil) is disposed in parallel with the supply air cooler in the circulation path of the low temperature side cooling system, and the low temperature side is provided in the coolant outlet passage of the supply air cooler. The oil cooler is provided with a supply air cooler side bypass passage that bypasses the heat exchanger and is connected to the outlet of the low temperature side heat exchanger, and a supply air cooler side thermostat that opens and closes the supply air cooler side bypass passage. Provided with an oil cooler side bypass passage that bypasses the low temperature side heat exchanger and is connected to the low temperature side heat exchanger outlet and an oil cooler side thermostat that opens and closes the oil cooler side bypass passage. An internal combustion engine equipped with a high and low temperature cooling system. The high-temperature side heat exchanger according to claim 1, wherein the low-temperature side heat exchanger and the high-temperature side heat exchanger are configured by a low-temperature side radiator and a high-temperature side radiator that cool the coolant with air constituting the cooling medium. An internal combustion engine with a low-temperature cooling system. 3. The high and low temperature cooling system according to claim 2, wherein the low temperature side radiator and the high temperature side radiator are arranged in parallel to a flow direction of cooling air from a cooling fan that supplies cooling air to the radiator. An internal combustion engine provided. 3. The high and low temperature cooling system according to claim 2, wherein the low temperature side radiator and the high temperature side radiator are arranged in series with respect to a flow direction of cooling air from a cooling fan that supplies cooling air to the radiator. An internal combustion engine provided. The low-temperature side heat exchanger and the high-temperature side heat exchanger are configured by a heat exchanger that cools the coolant by exchanging heat between the fresh water or seawater that constitutes the cooling medium and the coolant. An internal combustion engine comprising the high and low temperature cooling system according to claim 1 .

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