JP4748103B2 - Cooling device for internal combustion engine - Google Patents

Description

  The present invention relates to a cooling device for an internal combustion engine that improves the warm-up performance of a cooling system for the internal combustion engine.

A heat storage device for improving the warm-up effect of the internal combustion engine is provided as a cooling device for the internal combustion engine, and a cooling medium warmed by the heat storage device is supplied to the internal combustion engine before the internal combustion engine is started, and preheating is performed. It is known to supply a cooling medium by bypassing the radiator after the engine is started and before the warm-up is completed.
In addition, the engine cooling system, which is an internal combustion engine, needs to reduce heat loss in the warm-up process and realize warm-up early, but heat transfer and heat from the cooling water, which is a cooling medium, to each part of the engine. Radiation takes away heat and slows down warm-up.

  Also, when the discharge amount of a water pump such as idling is small, a sufficient amount of water cannot be obtained for each part, and it takes time to reach the part where the temperature rise is necessary, so more heat is taken away by the piping. Is called. This is a particularly serious problem in parts where it is necessary to supply hot water at an early stage, such as the effectiveness of the heater, the transmission warmer, and the anti-freezing piping of the throttle body.

  Also, particularly at high loads after warm-up, a sufficient amount of water is required, and therefore the discharge capacity of the water pump is set, so even if no amount of water is required, the fuel consumption depends on the power required for driving the water pump. There is also a problem that makes it worse.

By the way, conventionally, water-repellent resin is provided in the water jacket of the cooling device, the resin piping between the engine and the radiator, the EGR cooling passage, and the like to suppress thermal distortion, heat resistance, and corrosion prevention. Has been proposed (see Patent Documents 1 to 3).
In addition, in an engine water pump device, it has been proposed to prevent intrusion of cooling water into a bearing portion by coating a water-repellent synthetic resin on the inner wall of a pump housing (see Patent Document 4).

JP 2003-113737 A JP 2003-176721 A Japanese Patent Laid-Open No. 2002-4953 Japanese Utility Model Publication No. 63-29196

  However, in any of the above proposals, for example, it is not intended for early warm-up of functional parts such as a heater, but an early rise in heater temperature, an improvement in transmission rate of a transmission, etc., and an improvement in reliability by freezing the throttle. No measures have been taken to ensure

  In other words, there is a conflicting requirement between the restriction of the amount of water for improving the warm-up performance of the engine cooling system and the early warm-up of functional parts such as heaters and securing the amount of water after warm-up. Each part is mainly made of metal to ensure strength, and since it is easy to dissipate heat, countermeasures for early warm-up are eagerly desired.

  In view of the above problems, an object of the present invention is to provide a cooling device for an internal combustion engine that improves the warm-up performance of the cooling system of the internal combustion engine.

The invention of the first internal combustion engine cooling apparatus of the present invention for solving the above-described problems includes a main cooling medium path for circulating and cooling a cooling medium to the internal combustion engine , and a cooling medium discharged from the internal combustion engine. In an internal combustion engine cooling device comprising a sub-cooling medium path for supplying heat to the internal combustion engine after heat exchange by a heat exchanging means and a water pump for pumping the cooling medium , a fluid resistance is provided on the inner surface of the sub-cooling medium path. A reduction film or a fluid resistance reduction structure is provided.

In the invention of the cooling device for the second internal combustion engine according to the first invention, the heat exchange means for the cooling medium is a heater, a transmission warmer, or a throttle body, and the sub-cooling medium path is a heater path. A transmission warmer passage or a throttle body passage.

The invention of the cooling device for a third internal combustion engine according to the first invention is characterized in that the inner surface of the path of the cooling medium is inside a water pump.

The invention of the cooling device for a fourth internal combustion engine according to the fourth invention is characterized in that the interior of the water pump is one or both of the impeller surface and the inner wall surface of the pump casing.

According to a fifth aspect of the invention of the cooling device for an internal combustion engine, in any one of the first to fifth aspects, the fluid resistance reducing film is made of a fluorine resin material.

According to the present invention, since the fluid resistance reducing film or the fluid resistance reducing structure is provided on the inner surface of the sub cooling medium path , an air layer is easily formed between the inner wall of the path and the cooling medium. The amount of water to the functional parts aiming at early warm-up will be increased by reducing the fluid resistance. In addition, heat transfer from the cooling medium to the wall surface is hindered by the air layer, so that heat radiation is reduced and the functional component can be warmed up at a high temperature.
As a result, it is possible to improve reliability by increasing the heater temperature at an early stage, improving the transmission rate of the transmission, and releasing the throttle from freezing.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

(First embodiment)
FIG. 1 shows the overall configuration of a cooling system of an internal combustion engine to which a cooling device of the present invention is applied. The internal combustion engine 11 has a cylinder head 12 and a cylinder block 13, and a plurality (four in this embodiment) of cylinders 14 are formed in a line in the cylinder block 13. The internal combustion engine 11 is provided with a cooling device 20 that circulates cooling water through the internal combustion engine 11.

  The cooling device 20 is driven by a rotational torque of a crankshaft (not shown) of the internal combustion engine 11, a water pump 21 that pumps cooling water as a cooling medium to the internal combustion engine 11, and a cooling pumped by the water pump 21. Water is guided to the cylinder head 12 through a predetermined path to cool the cylinder head 12 and the cylinder block 13, respectively. The cooling water path 24 is a main cooling medium path, and the cooling water discharged from the cylinder head 12 is supplied to the inlet 22a of the radiator 22. The return water channel 25 that leads, the radiator outlet water channel 26 that guides the cooling water discharged from the outlet 22 b of the radiator 22 to the water pump 21 by the thermostat valve 28, and the radiator 22 bypasses the cooling water discharged from the cylinder head 12. A bar that leads to the water pump 21 via the thermostat valve 28. Has a path waterways 27.

  Furthermore, the cooling device 20 has a heater core 30 that is a heat exchange means for supplying cooling water heated using a heat source such as a heater to the internal combustion engine 11. The heater core 30 heats and stores the cooling water by a heat source such as a heater 31 a, the introduction water channel 32 a that guides the cooling water discharged from the cylinder head 12 to the heat storage container 31, and the cooling stored in the heat storage container 31. And a supply water channel 32b for guiding water to the water pump 21 by the thermostat valve 28. The introduction water passage 32a and the supply water passage 32b constitute a heater passage 32 that is a sub-cooling medium passage.

  When the cooling water temperature is equal to or lower than the set temperature, the thermostat valve 28 blocks the conduction of the cooling water from the radiator outlet water passage 26 to the water pump 21 and simultaneously from each of the bypass water passage 27 and the supply water passage 32b to the water pump 21. Allow the cooling water to pass through. On the other hand, when the cooling water temperature exceeds the set temperature, the thermostat valve 28 blocks the conduction of the cooling water from each of the bypass water passage 27 and the supply water passage 32b to the water pump 21 and at the same time from the radiator outlet water passage 26 to the water pump 21. Allow cooling water to pass through.

Thereby, when the cooling water temperature is equal to or lower than the set temperature, a circulation path through which the cooling water circulates in the path of the water pump 21 → the cooling water path 24 → the bypass water path 27 → the water pump 21 and the water pump 21 → the cooling water path 24 → A circulation path through which cooling water circulates along the path of the heater core 30 to the water pump 21 is formed.
On the other hand, when the cooling water temperature exceeds the set temperature, a circulation path that circulates through the path of the water pump 21 → the cooling water path 24 → the radiator 22 → the water pump 21 is formed.

  As other sub-cooling medium paths, for example, the cooling medium is circulated around the transmission warmer passage 41 and the throttle body 42 provided to circulate the cooling medium in the transmission (for CVT, AT, etc.) warmer 40. A stottle body passage 43 provided accordingly is provided. The present invention is not limited to the above-described transmission (for CVT, AT, etc.) warmer 40 or the like as a heat exchanging means, and any path can be used as long as it supplies a cooling medium to functional parts for early warm-up. It may be.

  Here, the transmission warmer passage 41 includes a water guide passage 41a that guides the cooling water to the warmer and a supply water passage 41b that guides the cooling water to the water pump 21 by the thermostat valve 28, and reduces the viscous resistance by the cooling medium. In order to prevent deterioration, the characteristics are fully exhibited.

  The throttle body passage 43 includes a water guide passage 43a that guides the cooling water to the periphery of the throttle body 42, and a supply water passage 43b that guides the cooling water to the water pump 21 by the thermostat valve 28. I try to prevent freezing.

In this embodiment, a fluid resistance reducing film or a fluid resistance reducing structure is provided on the inner surface of the sub-cooling medium path such as the heater passage 32, the transmission warmer passage 41, and the throttle body passage 43.
Here, the fluid resistance-reducing film or the fluid resistance-reducing structure is a film subjected to a so-called water-repellent treatment, for example, applied with a water-repellent resin or a water-repellent fine structure.

  Here, as the water repellent resin, a resin generally referred to as water repellency and having a contact angle θ between a solid and a liquid (water) of 90 ° or more is used. For example, a silicone resin having a contact angle θ with water of about 90 to 110 ° or polytetrafluoroethylene (PTFE) having a contact angle θ with water of about 110 ° can be used. It is not limited to this.

  Since the fluid resistance reducing film or the fluid resistance reducing structure is provided, an air layer is easily formed between the inner wall surface and the water flow as the cooling medium. As a result, the fluid resistance between the inner wall surface and the water is reduced, and the amount of water to the heater or the like, which is a functional component aiming for early warm-up, is increased.

And the shear force of an air layer is remarkably smaller than the shear force of water. In addition, heat transfer from the water to the wall surface is hindered by the air layer, and heat radiation is reduced. As a result, the functional component can be warmed up while maintaining a high temperature.
As a result, the heater temperature can be raised quickly, the transmission efficiency of the transmission can be improved, and the reliability can be improved by releasing the freezing of the throttle body.

  The water-repellent fine structure is not particularly limited as long as it has a structure in which fine protrusions of about several μm to several tens of μm are formed on the inner wall surface to reduce the fluid resistance of the cooling medium. Absent.

  Further, in the present embodiment, a fluid resistance reducing film or a fluid resistance reducing structure is provided in the sub-cooling medium path to warm up early, but the inner surfaces of the return water channel 25, the radiator outlet water channel 26, and the bypass water channel 27. In addition, a fluid resistance reducing film or a fluid resistance reducing structure may be provided in the sub-cooling medium path so as to improve the circulation efficiency of the cooling medium when the cooling medium is at a high temperature and to improve the cooling effect.

(Second Embodiment)
FIG. 2 is a schematic view of a water pump according to the second embodiment.
As shown in FIG. 2, the water pump 50 of the present embodiment forcibly circulates the cooling medium in the cooling passage, and the surface of the impeller 52 of the water pump that pumps the cooling medium by the pump casing body 51. Are provided with a fluid resistance reducing film or a fluid resistance reducing structure 60.
In the figure, reference numeral 53 denotes a pulley, 54 denotes a bearing, 55 denotes a belt, and 56 denotes a steam hole.

  Among the cooling systems, in the water pump 50, the flow rate of the cooling medium is the fastest part, resulting in a large temperature drop due to fluid resistance and wall surface heat transfer. Therefore, by providing a fluid resistance reducing film or fluid resistance reducing structure 60 on the surface of the impeller 52, the resistance due to contact with the cooling medium is reduced.

  Further, as shown in FIG. 3, not only the surface of the impeller 52 as shown in FIG. 2, but also the inner wall surface 51a of the pump casing body 51 is provided with a fluid resistance reducing film or a fluid resistance reducing structure 60. Thus, fluid resistance and heat transfer can be greatly reduced, water pump drive loss can be reduced, and heat dissipation from water during the warm-up process can be suppressed, thereby enabling early warm-up of the engine.

As a result, fuel consumption and emissions can be improved.
In this embodiment, the fluid resistance reducing coating or the fluid resistance reducing structure 60 is provided on both the impeller 52 surface and the pump casing inner wall surface 51a. However, the fluid resistance reducing coating or fluid resistance is provided only on the pump casing inner wall surface 51a. A mitigation structure 60 may be provided.

  In addition, the first embodiment and the second embodiment may be combined to further improve the warm-up performance of the cooling system of the internal combustion engine and improve the cooling efficiency of the internal combustion engine.

  As described above, the cooling structure of the internal combustion engine according to the present invention is provided with the fluid resistance reducing film or the fluid resistance reducing structure on the inner surface of the path of the cooling medium, thereby improving the warm-up property of the cooling system of the internal combustion engine. It is suitable for cooling internal combustion engines.

1 is a schematic view of a cooling device for an internal combustion engine according to Embodiment 1. FIG. It is the schematic of the water pump which concerns on Embodiment 2. FIG. It is the schematic of the other water pump which concerns on Embodiment 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Internal combustion engine 12 Cylinder head 13 Cylinder block 14 Cylinder 20 Cooling device 21 Water pump 22 Radiator 25 Return water path 26 Radiator outlet water path 27 Bypass water path 28 Thermostat valve 30 Heater core 31 Heat storage container 32 Heater path 40 Transmission (for CVT, for AT, etc. ) Warmer 41 Transmission warmer passage 42 Throttle body 43 Throttle body passage

Claims (5)

A main coolant path for circulating and cooling the coolant to the internal combustion engine ;
A sub cooling medium path for supplying a part of the cooling medium discharged from the internal combustion engine to the internal combustion engine after exchanging heat by the heat exchanging means ;
In a cooling device for an internal combustion engine comprising a water pump for pumping a cooling medium,
A cooling apparatus for an internal combustion engine, wherein a fluid resistance reducing film or a fluid resistance reducing structure is provided on an inner surface of a sub-cooling medium path . In claim 1,
The heat exchange means for the cooling medium is a heater, a transmission warmer or a throttle body,
The cooling apparatus for an internal combustion engine, wherein the sub-cooling medium path is a heater path, a transmission warmer path, or a throttle body path. In claim 1,
An internal combustion engine cooling device, wherein an inner surface of a path of the cooling medium is inside a water pump. In claim 3 ,
An internal combustion engine cooling device characterized in that the inside of the water pump is one or both of an impeller surface and a pump casing inner wall surface. In any one of Claims 1 thru | or 4 ,
The cooling device for an internal combustion engine, wherein the fluid resistance reducing film is made of a fluorine resin material.

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