Cooling system for internal combustion engines
The cooling system addresses steam buildup in internal combustion engines by using a hot bottle and strategic passage connections to ensure continuous coolant flow and steam release, maintaining efficient cooling throughout engine operation and shutdown.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- MITSUBISHI MOTORS CORP
- Filing Date
- 2024-12-25
- Publication Date
- 2026-07-07
Smart Images
Figure 2026112549000001_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to a cooling system for an internal combustion engine.
Background Art
[0002] Conventionally, a cooling system for an internal combustion engine having a passage through which cooling water for cooling a supercharger flows is known (see, for example, Patent Document 1). Since the exhaust gas passes through the supercharger, it becomes hot. Therefore, the cooling water flowing through the supercharger is likely to boil. When the cooling water boils, the steam expels the cooling water from the cooling passage of the supercharger.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] The cooling system of the internal combustion engine of Patent Document 1 vents the steam to the upper tank of the radiator by providing a passage connecting the outlet of the cooling passage in the supercharger and the upper tank of the radiator. However, during operation of the internal combustion engine, the pressure of the cooling water is high in the upper tank, and it is difficult for the steam to escape. Therefore, the steam is likely to remain in the cooling passage of the supercharger. As a result, it is not possible to ensure a sufficient amount of cooling water passing through the cooling passage of the supercharger. Further, the cooling system of the internal combustion engine of Patent Document 1 needs to prevent the cooling water from flowing from the cooling passage of the supercharger to the upper tank by using a check valve or the like.
[0005] An object of the present disclosure is to provide a cooling system for an internal combustion engine that makes it easy to ensure the amount of cooling water passing through the cooling passage of the supercharger.
Means for Solving the Problems
[0006] The cooling system for an internal combustion engine according to this disclosure is a cooling system for an internal combustion engine having an internal combustion engine and a supercharger for supercharging the intake air of the internal combustion engine, comprising: a radiator for cooling coolant flowing through the internal combustion engine; a hot bottle for removing vapor from the coolant; a first passage connecting the radiator and the hot bottle; a supercharger cooling passage for cooling the supercharger; and a second passage connecting the supercharger cooling passage and the first passage, wherein the first passage is connected to the upper part of the radiator via a first connection, the second passage is connected to the supercharger cooling passage via a second connection, and the first connection is located above the second connection. [Effects of the Invention]
[0007] According to this internal combustion engine cooling system, during engine operation, the coolant in the supercharger cooling passage flows from the second passage to the first passage, and from the first passage, the coolant easily flows to the hot bottle where the coolant pressure is lower. This makes it easier to ensure a sufficient amount of coolant flowing through the supercharger cooling passage while the internal combustion engine is running. When the internal combustion engine stops, the steam remaining in the supercharger cooling passage flows from the second passage to the first passage and easily flows to the top of the radiator. Furthermore, since the first connection point is located higher than the second connection point, the steam easily flows to the top of the radiator. [Brief explanation of the drawing]
[0008] [Figure 1] A diagram of the cooling water system for an internal combustion engine during operation according to one embodiment of the present disclosure. [Figure 2] A diagram of the cooling water system for an internal combustion engine while the engine is stopped, according to one embodiment of the present disclosure. [Figure 3] A diagram of the cooling water system for an internal combustion engine during operation according to another embodiment of the present disclosure. [Modes for carrying out the invention]
[0009] Hereinafter, one embodiment of the present disclosure will be described with reference to the drawings. In the drawings, the upper part of vehicle C is denoted as U.
[0010] As shown in Figure 1, the cooling system 1 for the internal combustion engine E (see ENG in Figure 1) is a reciprocating engine cooling system 1 having a supercharger E2 (see T / C in Figure 1) that supercharges the intake air of the internal combustion engine E. The cooling system 1 for the internal combustion engine E is mounted on the vehicle C. The cooling system 1 for the internal combustion engine E is located under the hood C1. The supercharger E2 in this embodiment is a turbocharger in which an exhaust turbine (not shown) and an intake compressor are connected coaxially.
[0011] The cooling system 1 for the internal combustion engine E includes an engine cooling passage 2, a radiator 4, a hot bottle 6, a first passage 8, a supercharger cooling passage 10, a second passage 12, and a third passage 14.
[0012] The engine cooling passage 2 is a passage for cooling the inside of the internal combustion engine E. The engine cooling passage 2 includes a water pump 2a (see W / P in Figure 1), a thermostat 2b (see TS in Figure 1), a radiator supply passage 2c, and a radiator return passage 2d.
[0013] Coolant flowing through the engine cooling passage 2 passes through the inside of the internal combustion engine E and flows into the radiator supply passage 2c. The radiator supply passage 2c is connected to the radiator 4. The coolant flowing through the radiator supply passage 2c is supplied to the radiator 4. The radiator return passage 2d is connected to the radiator 4. The coolant that has passed through the radiator 4 is supplied to the radiator return passage 2d. A thermostat 2b is located on the radiator return passage 2d. The thermostat 2b is an on / off valve that opens and closes the radiator return passage 2d. For example, when the coolant temperature reaches 40°C or higher, the thermostat 2b opens the radiator return passage 2d and supplies the coolant to the water pump 2a. The coolant flowing through the engine cooling passage 2 is circulated by the water pump 2a. The water pump 2a in this embodiment is a mechanical pump that rotates its impeller using the driving force of a motor or the internal combustion engine E. The water pump 2a rotates while the internal combustion engine E is running.
[0014] The radiator 4 cools the coolant flowing through the internal combustion engine E. The radiator 4 has an upper tank 4a, a radiator core 4b, and a lower tank 4c. The upper tank 4a is connected to the radiator supply passage 2c.
[0015] The radiator core 4b is located below the upper tank 4a. Coolant supplied to the upper tank 4a flows through the radiator core 4b. The radiator core 4b is a heat exchanger that exchanges heat between the outside air of the vehicle C and the coolant. The coolant that passes through the radiator core 4b has a lower temperature.
[0016] The lower tank 4c is located beneath the radiator core 4b. The lower tank 4c is connected to the radiator return passage 2d.
[0017] The hot bottle 6 is a device that removes air from the coolant flowing through the cooling system 1. In this embodiment, the hot bottle 6 is a sealed container made of metal or heat-resistant resin with an internal space. The hot bottle 6 is supplied with coolant flowing from the supercharger cooling passage 10, or coolant containing air discharged from the upper tank 4a, into its internal space. The coolant fills the lower part of the space in the hot bottle 6, and the upper space of the hot bottle 6 is filled with air. The air in the coolant is discharged into the upper space of the hot bottle 6. The pressure of the coolant inside the hot bottle 6 is lower than the pressure of the coolant in the upper tank 4a of the radiator 4. Therefore, the coolant flows easily from the upper tank 4a to the hot bottle 6.
[0018] In this embodiment, the highest position 6x of the hot bottle 6 body is positioned lower than the highest position E2x of the supercharger. Furthermore, the highest position 6x of the hot bottle 6 body is positioned lower than the upper end of the upper tank 4a of the radiator 4. From the viewpoint of maintainability, the hot bottle 6 is preferably positioned approximately between the radiator 4 and the internal combustion engine E at the front of the vehicle C. However, in Figures 1 to 3, the hot bottle 6 is positioned behind the supercharger E2 to make the vertical positions of the radiator 4, supercharger E2, and hot bottle 6 easier to understand.
[0019] The hot bottle 6 is connected at the bottom to the hot bottle discharge passage 6a of the engine cooling passage 2. The hot bottle discharge passage 6a is connected upstream of the water pump 2a of the engine cooling passage 2. The cooling water inside the hot bottle 6 is sucked up by the water pump 2a through the hot bottle discharge passage 6a.
[0020] The first passage 8 is a passage connecting the radiator 4 and the hot bottle 6. The first passage 8 is connected to the upper tank 4a of the radiator 4 via the first connection portion 8a. The first passage 8 is connected to the hot bottle 6 via the fourth connection portion 8b. In the present embodiment, the first passage 8 penetrates into the hot bottle 6. Specifically, the fourth connection portion 8b is disposed at a position immersed in the cooling water stored in the hot bottle 6. In the present embodiment, the vertical position of the fourth connection portion 8b is the same as the position of the third connection portion 14b.
[0021] The supercharger cooling passage 10 is a passage for cooling the supercharger E2. In the present embodiment, the supercharger cooling passage 10 is disposed around the bearing of the shaft that rotates the exhaust turbine and the intake compressor. The supercharger cooling passage 10 cools the lubricating oil around the shaft by cooling the bearing of the supercharger E2. When the amount of cooling water in the supercharger cooling passage 10 becomes insufficient, the lubricating oil hardens due to heat, and the shaft is likely to stick to the bearing. The upstream of the supercharger cooling passage 10 is connected to the supercharger supply passage 10a branched from the engine cooling passage 2.
[0022] The second passage 12 is a passage connecting the supercharger cooling passage 10 and the first passage 8. In the present embodiment, the second passage 12 is a bypass passage 12a branched from the third passage 14 and connected to the first passage 8. The third passage 14 is a passage connecting the hot bottle 6 and the supercharger cooling passage 10. The third passage 14 is connected to the supercharger cooling passage 10 via the second connection portion 14a. The first connection portion 8a is located above the second connection portion 14a. The third passage 14 is connected to the hot bottle 6 via the third connection portion 14b.
[0023] In this embodiment, the third passage 14 penetrates into the hot water bottle 6. Specifically, the third connection portion 14b is disposed at a position immersed in the cooling water stored in the hot water bottle 6. The diameter D2 of the bypass passage 12a is smaller than the diameter D1 of the first passage 8 and the diameter D3 of the third passage 14.
[0024] As described above, in this embodiment, the third connection portion 14b is disposed at a position immersed in the cooling water stored in the hot water bottle 6. This is because when the third connection portion 14b is located above the cooling water stored in the hot water bottle 6, the cooling water discharged from the third connection portion 14b drips onto the water surface in the hot water bottle 6, suppressing the bubbling of the cooling water in the hot water bottle 6. When the position of the third connection portion 14b is lowered to suppress the bubbling of the cooling water in the hot water bottle 6, the second connection portion 14a is located above the third connection portion 14b. Therefore, when the internal combustion engine E stops, the steam remaining in the supercharger cooling passage 10 of the supercharger E2 is difficult to escape.
[0025] As shown by the arrow in FIG. 1, during the operation of the internal combustion engine E, that is, during the operation of the water pump 2a, the cooling water is circulated by the water pump 2a. Since there is air in the upper space of the hot water bottle 6, the cooling water in the upper tank 4a is at a higher pressure than the cooling water in the hot water bottle 6.
[0026] The cooling water in the upper tank 4a flows through the first passage 8 and into the hot water bottle 6. The diameter D2 of the bypass passage 12a is smaller than the diameter D3 of the first passage 8. Therefore, it is difficult for the cooling water passing through the first passage 8 to flow into the bypass passage 12a. As a result, it is difficult to inhibit the flow of air mixed into the cooling water flowing from the supercharger cooling passage 10 to the hot water bottle 6 through the bypass passage 12a.
[0027] Coolant that branches off from the engine cooling passage 2 to the turbocharger supply passage 10a flows into the turbocharger cooling passage 10. The coolant that has passed through the turbocharger cooling passage 10 flows through the third passage 14 to the hot bottle 6. In addition, a portion of the coolant that has passed through the turbocharger cooling passage 10 flows through the bypass passage 12a and the first passage 8 to the hot bottle 6. As a result, it is easy to ensure a sufficient amount of coolant in the turbocharger cooling passage 10. Furthermore, the diameter D2 of the bypass passage 12a is smaller than the diameter D3 of the third passage 14. Therefore, the coolant mainly flows through the third passage 14 to the hot bottle 6. This makes it less likely for the flow of coolant that has passed through the turbocharger cooling passage 10 to obstruct the flow of coolant in the first passage 8 that flows from the upper tank 4a to the hot bottle 6.
[0028] As shown by the dots in Figure 2, when the internal combustion engine E is stopped, i.e., when the water pump 2a is stopped, the heat from the supercharger E2 causes the cooling water in the supercharger cooling passage 10 to boil, easily generating steam. However, according to the cooling system 1 for the internal combustion engine E of this disclosure, the steam in the supercharger cooling passage 10 flows from the third passage 14 through the bypass passage 12a to the first passage 8. As a result, the pressure caused by the steam is released from the supercharger supply passage 10a, the supercharger cooling passage 10, and the third passage 14, making it easier for the supercharger cooling passage 10 to be filled with cooling water. Consequently, even after the internal combustion engine E is stopped, cooling water remains in the supercharger cooling passage 10, making it easier to cool the bearings.
[0029] If there is no bypass passage 12a, the steam generated by the boiling of the cooling water in the turbocharger cooling passage 10 is released from the third passage 14. In this case, at the third connection 14b at the tip of the third passage 14, the steam pressure balances the water pressure at the tip of the third passage 14. This pressure also pushes down the water level in the turbocharger supply passage 10a. The pushed-down cooling water falls to the same vertical position 6x1 as the third connection 14b, which is located below the second connection 14a. As a result, the amount of cooling water in the turbocharger cooling passage 10 is reduced. In this embodiment, the vertical position 6x1 of the third connection 14b is below the connection 10b between the turbocharger supply passage 10a and the turbocharger cooling passage 10. In this structure, the coolant flows down to the same position 6x1 as the vertical position of the third connection part 14b, that is, below the connection part 10b between the turbocharger supply passage 10a and the turbocharger cooling passage 10, causing the coolant to stop flowing within the turbocharger supply passage 10a. As a result, coolant is no longer supplied to the turbocharger cooling passage 10.
[0030] As explained above, this disclosure provides a cooling system 1 for an internal combustion engine E that makes it easier to ensure the amount of coolant passing through the supercharger cooling passage 10 of the supercharger E2.
[0031] <Other Embodiments> Although embodiments of the present disclosure have been described above, the present disclosure is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention. In particular, the various modifications described herein can be combined as needed.
[0032] In the above embodiment, an example was described in which the highest position 6x of the hot bottle 6 is positioned lower than the highest position E2x of the supercharger, but this disclosure is not limited thereto. The hot bottle 6 only needs to have the position of the third connection portion 14b lower than the second connection portion 14a.
[0033] In the above embodiment, the second passage 12 was described as a bypass passage 12a branching off from the third passage 14, but the disclosure is not limited thereto. As shown in Figure 3, for example, the third passage 14 may not be provided, and the second passage 12 may be connected to the supercharger cooling passage 10 and the second passage 12 may be connected to the first passage 8. [Explanation of Symbols]
[0034] 1: Cooling system, 2: Engine cooling passage 2a: Water pump, 2b: Thermostat 2c: Radiator supply passage, 2d: Radiator return passage 4: Radiator, 4a: Upper tank, 4b: Radiator core, 4c: Lower tank 6: Hot bottle, 6a: Hot bottle discharge passage, 6x: Top position 8: First passage, 8a: First connection point, 8b: Fourth connection point 10: Supercharger cooling passage, 10a: Supercharger supply passage 12: Second passage, 12a: Bypass passage 13: 3rd aisle 14: Third passage, 14a: Second connection, 14b: Third connection C: Vehicle C1: Food E: Internal combustion engine, E2: Supercharger, E2x: Top position
Claims
1. A cooling system for an internal combustion engine, comprising an internal combustion engine and a supercharger for supercharging the intake air of the internal combustion engine, A radiator that cools the coolant flowing through the internal combustion engine, A hot bottle for removing air from the cooling water, A first passage connecting the radiator and the hot bottle, A supercharger cooling passage that cools the supercharger, A second passage connecting the supercharger cooling passage and the first passage, Equipped with, The first passage is connected to the upper part of the radiator via a first connection part. The second passage is connected to the supercharger cooling passage via the second connection part. The first connection portion is located above the second connection portion. Cooling system for an internal combustion engine.
2. A third passage connecting the supercharger cooling passage and the hot bottle, Furthermore, The third passage is connected to the hot bottle via the third connection part. The second passage is a bypass passage that branches off from the third passage. Cooling system for an internal combustion engine according to claim 1.
3. The diameter of the bypass passage is smaller than the diameter of the first passage and the diameter of the third passage. Cooling system for an internal combustion engine according to claim 2.
4. The cooling system for an internal combustion engine according to claim 2 or 3, wherein the third connection portion is positioned to be immersed in the cooling water stored in the hot bottle.