Thermal management structure of V-type engine

Abstract

To provide a heat management structure for a V-type engine, which can suppress heat damage caused by exhaust system devices housed in an inner space between both banks and efficiently dissipate heat from the devices.SOLUTION: An engine cover 20 is provided with an opening 21 on the front side of the center. A part of an insulator 30 is exposed from the opening 21 of the engine cover 20, and the part of the insulator 30 exposed from the opening 21 is provided with slits 31a to 31c and louvers 32a to 32c. The louvers 32a to 32c are provided so as to incline toward the front of a vehicle. A running wind enters the opening 21, then hits the inclined surfaces of the louvers 32a to 32c to change its direction, passes through the slits 31a to 31c, and enters an inner space between both banks.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a thermal management structure for a V-type engine in which an exhaust system device connected after the exhaust manifold of the V-type engine is housed in the inner space of both banks. [Background technology]

[0002] Conventionally, in vehicles equipped with a V-type engine, the intake system or exhaust system is placed between the two banks to efficiently utilize the space in the engine compartment. An engine cover is then attached to cover the intake system or exhaust system for noise reduction and design improvement. Because of this structure, heat tends to build up in the space inside the two banks, so technologies have been devised to efficiently release the heat and prevent heat damage.

[0003] For example, in Patent Document 1, an intake system is placed between both banks of a V-type engine, and the engine cover is provided with an air intake to take in air from the fan and a heat insulator that directs the taken-in air to create an upward current. The upward current is then released through louvers provided on the top surface of the cover, so that the hot air inside the bank is discharged upward and rearward through the louvers together with the generated upward current. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-331636 Summary of the Invention [Problem to be solved by the invention]

[0005] In the past, locating the exhaust system between the two banks of a V-type engine tended to trap heat, so it was common to place the intake system between the two banks. However, in recent years, particularly in diesel engine vehicles, it has become necessary to keep the catalysts used in the exhaust gas purification system at an appropriate temperature so that they can be activated and kept warm quickly, and efforts are underway to deliberately place them in the space inside the two banks where heat is trapped.

[0006] In other words, by using exhaust heat, the catalyst can be effectively heated and kept warm from the time the engine is started. However, if the exhaust system is placed in the inner space of both banks where heat tends to build up, the risk of heat damage increases. Therefore, once the inner space reaches an appropriate temperature for the catalyst, appropriate heat management is required, which uses exhaust heat on the one hand, while at the same time dissipates heat from the exhaust system to prevent heat damage by preventing the temperature of the inner space from rising too much.

[0007] In this regard, for example, in the structure of a V-type engine as in the cited document 1, the intake system is housed between the two banks, but if the exhaust system were to be housed between the two banks, there would be nothing to block the engine cover from the heat source (exhaust system), so there would be a high possibility of heat damage occurring to the engine cover. In other words, the wind that has passed through a relatively high-temperature heat source hits the heat insulator and passes directly through the louvers of the engine cover. The engine cover is made of resin, so there is a high risk of heat damage.

[0008] The present invention was devised in consideration of these points, and its objective is to provide a thermal management structure for a V-engine that can suppress thermal damage caused by the exhaust system equipment housed in the inner space of both banks while also efficiently dissipating heat from the equipment. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, the first invention of the present invention is a thermal management structure for a V-type engine in which an exhaust system device connected after the exhaust manifold of the V-type engine is housed in the inner space of both banks, the thermal management structure for a V-type engine having an engine cover attached so as to cover the upper part of the inner space, and an insulator disposed between the engine cover and the exhaust system device to block heat transfer from the exhaust system device to the engine cover.

[0010] Next, a second invention of the present invention is a thermal management structure for a V-type engine related to the first invention described above, wherein an opening is provided in a portion of the upper surface of the engine cover, and a portion of the insulator is exposed from the opening.

[0011] Next, the third invention of the present invention is a thermal management structure for a V-type engine related to the second invention described above, wherein a portion of the insulator exposed from the opening is provided with a slit whose longitudinal direction is perpendicular to the direction of travel of the vehicle when the V-type engine is mounted on the vehicle.

[0012] Next, a fourth invention of the present invention is a thermal management structure for a V-type engine related to the third invention above, wherein a plate-shaped louver extending in the longitudinal direction of the slit is provided on the long side of the slit facing the rear of the vehicle, so as to be inclined toward the front of the vehicle.

[0013] Next, a fifth aspect of the present invention is a thermal management structure for a V-engine according to any one of the first to fourth aspects of the present invention, wherein the V-engine has a turbocharger equipped with a turbine as the exhaust system device, and the insulator is arranged so as to cover at least the turbine.

[0014] Next, a sixth aspect of the present invention is a thermal management structure for a V-type engine relating to any one of the first to fifth aspects of the present invention, wherein the engine cover is inclined so that, when the V-type engine is mounted on a vehicle, the rear side of the vehicle is higher than the front side. Effect of the Invention

[0015] According to the first invention, the insulator is positioned between the engine cover and the exhaust system, so that the insulator is located in a position that directly receives heat generated by the exhaust system and blocks the transfer of heat from the exhaust system to the engine cover. Furthermore, the insulator does not function to block (or change) the flow of air, such as the running wind or the cooling wind from a cooling fan, that enters the inner space between the two banks and flows between the exhaust system, and the heat from the exhaust system is appropriately dissipated. Therefore, heat damage from the exhaust system housed in the inner space between the two banks is suppressed, and the heat from the exhaust system can be efficiently dissipated.

[0016] According to the second aspect of the present invention, when the vehicle is running, the wind from the vehicle enters the inner spaces of both banks through the opening and mixes the air in the inner spaces of both banks, which promotes heat dissipation from the exhaust system. Also, when the engine is stopped, the hot air trapped in the inner spaces of both banks rises toward the engine cover, so the opening can function as an outlet for the rising hot air.

[0017] According to the third aspect of the present invention, when the vehicle is running, the wind from the opening passes through the slits in the insulator into the inner spaces of both banks and flows between the exhaust system devices located below the insulator, which further promotes heat dissipation from the exhaust system devices. Also, when the engine is stopped, hot air trapped in the inner spaces of both banks rises toward the engine cover, so the slits and the openings can function as exhaust ports for the rising hot air.

[0018] According to the fourth aspect of the present invention, the airflow hitting the inclined surface of the louver changes direction and passes through the slits into the inner space between the two banks, thereby increasing the amount of airflow flowing between the exhaust system devices located below the insulators, and further facilitating heat dissipation from the exhaust system devices.

[0019] According to the fifth aspect of the present invention, the turbocharger is usually set closer to the engine cover than other exhaust system devices, and the turbine is located upstream of the exhaust and is therefore hot. Since an insulator is interposed between the turbocharger having such characteristics and the engine cover, heat damage to the engine cover can be prevented.

[0020] According to the sixth aspect of the present invention, when the engine cover is not inclined, the area of ​​the opening that appears when the engine cover is viewed from the direction of travel is zero, whereas when the engine cover is inclined, the area becomes larger. The increased area allows more wind to be drawn into the inner spaces of both banks, further facilitating heat dissipation from the exhaust system. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a diagram showing a state in which a V-type engine according to an embodiment of the present invention is mounted on a vehicle. [Diagram 2] FIG. 1 is an exploded perspective view for explaining an overview of a V-type engine according to an embodiment of the present invention. [Diagram 3] FIG. [Figure 4] FIG. 1 is a front view of a V-type engine according to an embodiment of the present invention. [Diagram 5] 5 is a cross-sectional view of FIG. 4 . [Figure 6] FIG. 1 is a plan view of a V-type engine according to an embodiment of the present invention. [Figure 7] FIG. 2 is a diagram for explaining the action and effect of the V-type engine according to this embodiment when the vehicle is running. [Figure 8] FIG. 4 is a diagram for explaining the operation and effect when the V-type engine according to the present embodiment is stopped. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] [V-engine overview (Fig. 1-3)] An embodiment for carrying out the present invention will be described below with reference to the drawings. First, an overview of a V-type engine 10 mounted on a vehicle 1 will be described with reference to Figs. 1 to 3. Note that when "front", "rear", "left", "right", "upper", and "lower" are shown in the drawings, "front" refers to the front direction of the vehicle 1, and "rear" refers to the rear direction of the vehicle 1. Also, "left" refers to the left direction of the vehicle 1, and "right" refers to the right direction of the vehicle 1. "Up" refers to the upper direction of the vehicle 1, and "lower" refers to the lower direction of the vehicle 1.

[0023] As shown in Fig. 1, a V-type engine 10 is placed, for example, vertically in an engine room 2 of a vehicle 1. In other words, a rotating axis 11 of a crankshaft (not shown) housed in a crankcase 50 of the V-type engine 10 faces in the front-to-rear direction of the vehicle 1. In addition to the V-type engine 10, a radiator, a cooling fan, a battery, an air cleaner, and other piping, wiring, etc. are also arranged in the engine room 2, but are not shown in Fig. 1.

[0024] As shown in Fig. 2, the V-engine 10 has a right bank 51 and a left bank 52 (corresponding to both banks) in which a plurality of cylinders are formed, and a predetermined bank angle is set between the right bank 51 and the left bank 52. An inner space 53 is formed between the right bank 51 and the left bank 52, and in order to effectively utilize the space in the engine room 2, engine accessories are accommodated in the inner space 53. The engine accessories mainly include exhaust system devices, such as an exhaust gas purification device and a turbocharger equipped with a turbine as an exhaust system device. Note that in order to further effectively utilize the space, the inner space 53 may accommodate a part of an intake system device in addition to the exhaust system device.

[0025] 2, the engine cover 20 is attached so as to cover the upper part of the inner space 53. The engine cover 20 is made of, for example, resin and has a predetermined design molded on its surface, improving the appearance when a user looks at the V-type engine 10 inside the engine compartment 2. In other words, unless the engine cover 20 is removed from the V-type engine 10, the engine accessories housed in the inner space 53 cannot be seen when the engine compartment 2 is opened, which is one of the factors that causes heat to build up in the inner space 53.

[0026] 2, the engine cover 20 has an opening 21 in a part of the upper surface. When the vehicle 1 is traveling, a traveling wind 3 (see FIG. 1) enters the engine room 2 from the front grill (not shown), and the opening 21 serves as an inlet for directing the traveling wind 3 into the inner space 53 of the V-engine 10. Also, when the V-engine 10 is stopped (dead soak) immediately after the V-engine 10 becomes hot due to high-load operation, without going through low-load operation such as idling, hot air generated by the exhaust system rises toward the engine cover 20, and the opening 21 also functions as an outlet for the rising hot air.

[0027] The insulators 30, 40 are disposed between the engine cover 20 and the exhaust system. The insulators 30, 40 are separate bodies, with the insulator 30 disposed on the front side of the inner space 53 and the insulator 30 disposed on the rear side of the inner space 53. In other words, the insulators 30, 40 are disposed below the engine cover 20, and the exhaust system is disposed further below the insulators 30, 40. The insulators 30, 40 are made of a metal such as aluminum, and block heat transferred from the exhaust system to the engine cover 20.

[0028] 3, the insulator 30 has slits 31a to 31c and louvers 32a to 32c. The longitudinal direction of the slits 31a to 31c is perpendicular to the traveling direction (front-rear direction) of the vehicle 1, and, for example, three of the slits 31a to 31c are formed in the insulator 30. The louvers 32a to 32c are plate-shaped extending in the longitudinal direction of each of the slits 31a to 31c, and are provided on the long side 33 of the slits 31a to 31c on the rear side of the vehicle 1 so as to incline toward the front of the vehicle 1 (see FIG. 6).

[0029] [Engine cover and insulator structure and features (Fig. 4 to Fig. 6)] 5 and 6, the engine cover 20 has an opening 21 provided forward of the center. The engine cover 20 is also attached at an incline so that the rear side of the vehicle 1 is higher than the front side, and has a predetermined angle θ with respect to the horizontal plane. Therefore, as shown in FIG. 4, in a front view of the V-type engine 10 seen from the front of the vehicle 1, the upper surface of the engine cover 20 appears, and as a result, the opening 21 provided on the upper surface is also visible, making it easier for the running wind 3 to enter through the opening 21.

[0030] A portion of the insulator 30 is exposed from the opening 21 of the engine cover 20. The slits 31a to 31c and the louvers 32a to 32c are provided in the portion of the insulator 30 exposed from the opening 21. The louvers 32a to 32c are provided so as to incline toward the front of the vehicle 1, as described above.

[0031] Here, in the case of the V-type engine 10, two turbochargers (twin turbo 61) are often provided. The turbine of the turbocharger is connected immediately downstream of the exhaust manifold, and therefore becomes particularly hot in the exhaust system. Therefore, if cooling by the running wind 3 (see FIG. 1) is expected, it is better to have it closer to the opening 21. Also, since a predetermined bank angle is set for the right bank 51 and the left bank 52, the inner space 53 is a space that expands from the bottom to the top, so that the twin turbo 61 is necessarily accommodated up to the upper side of the inner space 53. As a result, the twin turbo 61 is closer to the engine cover 20. The insulator 30 is mainly attached so as to cover such a twin turbo 61 that is close to the bottom surface of the engine cover 20.

[0032] On the other hand, the insulator 40 has a front end 41 overlapped with a rear end 34 of the insulator 30, and is attached so as to be spaced apart from the engine cover 20 compared to the insulator 30 and mainly cover the exhaust gas purification device 62. Also, the insulator 40 is attached so as to be spaced apart from the engine cover 20 as it moves rearward, because the exhaust gas purification device 62 does not require as much storage space as the above-mentioned twin turbo 61. Note that, in the space secured between the insulator 40 and the engine cover 20, for example, an intercooler or the like, which is an intake system device, may be disposed.

[0033] ●[Functions and effects of the engine cover opening and the insulator slits and louvers (Fig. 7, Fig. 8)] 7, when the vehicle 1 is traveling, the traveling wind 3 enters the opening 21. At this time, the engine cover 20 is tilted by a predetermined angle θ, and the normal vector component of the traveling wind 3 with respect to the opening 21 (opening surface) increases, so that more traveling wind 3 can be taken in compared to when the engine cover 20 is not tilted (the normal vector component is 0).

[0034] The traveling wind 3 that has entered the opening 21 then changes direction when it hits the inclined surfaces of the louvers 32a to 32c, passes through the slits 31a to 31c, and enters the inner space 53. In this way, by providing the louvers 32a to 32c, it is possible to guide more of the traveling wind 3 into the inner space 53 compared to a structure in which only the slits 31a to 31c are provided.

[0035] The running wind 3 guided into the inner space 53 passes between the exhaust system (twin turbo 61, exhaust gas purification device 62) and the insulator 30, and reaches the rear end 34 of the insulator 30 while reducing the heat of the exhaust system, and then passes between the exhaust system and the insulator 40, and passes through the inner space 53 while similarly reducing the heat of the exhaust system.

[0036] 8, when the engine of the vehicle 1 is stopped, not only is there no wind 3 generated, but unless the vehicle is designed to turn on the cooling fan after the engine is stopped, there is no air flow between the exhaust system and the insulators 30, 40. Therefore, a large amount of heat is generated from the exhaust system, particularly during dead soak. However, when the hot air trapped in the inner space 53 rises toward the engine cover, it flows toward the insulator 30 along the underside of the insulator 40, and is finally discharged from the slits 31a to 31c and the opening 21.

[0037] The thermal management structure for a V-engine of the present invention is not limited to the appearance, configuration, structure, etc. described in this embodiment, and various modifications, additions, and deletions are possible without departing from the spirit of the present invention. For example, in this embodiment, three slits and three louvers are provided, but the number may be, for example, two or four, as long as it can guide the wind generated while the engine is running into the inner space or can release hot air trapped in the inner space after the engine is stopped.

[0038] In addition, in this embodiment, the insulator 40 is provided separately from the insulator 30, but they may be integrated into one insulator. Conversely, the insulator 40 may be further divided into two or more insulators.

[0039] In addition, in this embodiment, the V-type engine is described as being installed vertically in the engine room of the vehicle, but it may be installed horizontally. In other words, even in the case of a horizontal installation, if a slit is provided whose longitudinal direction is perpendicular to the traveling direction of the vehicle, and a plate-like louver extending in the longitudinal direction of the slit is provided so as to be inclined toward the front of the vehicle, the traveling wind can be guided into the inner space.

[0040] Furthermore, in the present embodiment, the description has been given of an arrangement in which two superchargers are provided (twin turbo), but the arrangement may also be such that one supercharger is provided. [Explanation of symbols]

[0041] 1 vehicle 2. Engine Room 3. Driving wind 10 V-engine 11 Rotation axis 20 Engine cover 21 Opening 30 Insulator 31a~31c Slit 32a~32c Louver 33 Long side 34 Rear end 40 Insulator 41 Front end 50 Crankcase 51 Right Bank 52 Left Bank 53 Inner Space 61 Twin Turbo 62 Exhaust gas purification device θ angle

Claims

1. A thermal management structure for a V-type engine in which an exhaust system device connected to the exhaust manifold of the V-type engine is housed in the inner space of both banks, An engine cover attached so as to cover an upper portion of the inner space; an insulator disposed between the engine cover and the exhaust system to block heat transferred from the exhaust system to the engine cover; having an opening is provided in a part of an upper surface of the engine cover, and a part of the insulator is exposed through the opening; Thermal management structure of a V-engine.

2. 2. A thermal management structure for a V-type engine according to claim 1, a slit having a longitudinal direction perpendicular to a traveling direction of the vehicle when the V-type engine is mounted on the vehicle is provided in a portion of the insulator exposed from the opening. Thermal management structure of a V-engine.

3. 3. A thermal management structure for a V-type engine according to claim 2, A plate-shaped louver extending in the longitudinal direction of the slit is provided on a long side of the slit on the rear side of the vehicle so as to incline toward the front of the vehicle. Thermal management structure of a V-engine.

4. A thermal management structure for a V-type engine according to any one of claims 1 to 3, the V-type engine has a turbocharger equipped with a turbine as the exhaust system device, The insulator is disposed so as to cover at least the turbine. Thermal management structure of a V-engine.

5. A thermal management structure for a V-type engine according to any one of claims 1 to 4, The engine cover is inclined so that the rear side of the vehicle is higher than the front side when the V-type engine is mounted on the vehicle. Thermal management structure of a V-engine.

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