Cover for vehicular exhaust manifold

Abstract

The present invention serves both to improve the durability of an exhaust manifold 12 and to protect surrounding engine devices from heat damage by reducing radiant heat issuing from the exhaust manifold 12.　This cover 14 for an exhaust manifold has an upper cover 32 that covers the exhaust manifold 12 from above, and a lower cover 34 that covers same from below. Streaming air that flows from vehicle frontward toward vehicle rearward is introduced into a top-side air passage P1 and a bottom-side air passage P2 through a front space S1 having a vertical direction space d1 between the front edge of the upper cover 32 and the front edge of the lower cover 34. The vertical direction space d1 between the front edge of the upper cover 32 and the front edge of the lower cover 34 is formed greater than a vertical direction space d2 between the rear edge of the upper cover 32 and the rear edge of the lower cover 34.

Description

Vehicle exhaust manifold cover

[0001] The present invention relates to a cover for an exhaust manifold of a vehicle.

[0002] The exhaust manifold is heated by the exhaust gas emitted from the engine, resulting in high temperatures and causing heat damage to peripheral devices located near the exhaust manifold. For this reason, an exhaust manifold cover has been provided that covers the exhaust manifold to block the radiant heat emitted from the exhaust manifold and protect the peripheral devices from heat damage (see Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2005-248778

[0004] In the above-mentioned conventional technology, while the exhaust manifold cover shields radiant heat, no particular consideration is given to cooling the exhaust manifold, and there is room for improvement in improving the durability of the exhaust manifold. The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide an exhaust manifold cover for a vehicle that improves the durability of the exhaust manifold and is advantageous in reducing radiant heat radiated from the exhaust manifold and protecting peripheral equipment from heat damage.

[0005] To achieve the above object, one embodiment of the present invention is an exhaust manifold cover for a vehicle having an upper cover that covers an exhaust manifold from above and a lower cover that covers it from below, wherein the vertical distance between the front end of the upper cover and the front end of the lower cover is larger than the vertical distance between the rear end of the upper cover and the rear end of the lower cover. Another embodiment of the present invention is characterized in that a front gap is formed between the front end of the upper cover and the front end of the lower cover, a rear gap is formed between the rear end of the upper cover and the rear end of the lower cover, and the length of the front gap in the vehicle width direction is larger than the length of the rear gap in the vehicle width direction. Another embodiment of the present invention is characterized in that the exhaust manifold includes a plurality of pipe bodies attached to a cylinder head of a longitudinally mounted engine and an exhaust manifold where the plurality of pipe bodies gather and are attached to an exhaust pipe, the exhaust manifold having a length along the fore-and-aft direction of the vehicle, and the exhaust manifold is located at a position closer to the front of the vehicle than the center of the length of the exhaust manifold. In one embodiment of the present invention, when the upper cover is viewed from above and the lower cover is viewed from below, the ends of the upper cover and the lower cover that are farther from the cylinder head extend on an inclined curve that approaches the cylinder head as it approaches the rear of the vehicle at a location rearward of the exhaust manifold, an upper flange that protrudes downwardly extends along the end of the upper cover that extends on the curve, and a lower flange that protrudes upwardly extends along the end of the lower cover that extends on the curve, with a gap being ensured between the lower end of the upper flange and the upper end of the lower flange.In addition, one embodiment of the present invention is characterized in that the exhaust manifold comprises a cylinder head mounting flange provided at the end of the plurality of pipe bodies and an exhaust pipe mounting flange provided at the end of the exhaust collection section, the upper cover and the lower cover are each attached to a plurality of mounting portions provided on the exhaust manifold, and at least one mounting portion of the plurality of mounting portions for mounting the upper cover and at least one mounting portion of the plurality of mounting portions for mounting the lower cover are provided on the cylinder head mounting flange or the exhaust pipe mounting flange.

[0006] According to one embodiment of the present invention, the vertical distance between the front end of the upper cover and the front end of the lower cover is greater than the vertical distance between the rear end of the upper cover and the rear end of the lower cover, so that more airflow is taken in between the upper cover and the upper surface of the exhaust manifold and between the lower cover and the lower surface of the exhaust manifold, which is advantageous for efficiently cooling the exhaust manifold by the airflow. This is not only advantageous for improving the durability of the exhaust manifold, but also for promoting cooling of the exhaust manifold, which reduces radiant heat emitted from the exhaust manifold and protects peripheral equipment from heat damage. Furthermore, if the length of the front gap in the vehicle width direction is greater than the length of the rear gap in the vehicle width direction, this is more advantageous for taking in more airflow between the upper cover and the upper surface of the exhaust manifold and between the lower cover and the lower surface of the exhaust manifold, which is advantageous for improving the durability of the exhaust manifold and reducing radiant heat from the exhaust manifold to protect peripheral equipment from heat damage. Furthermore, if the exhaust manifold is located closer to the front of the vehicle than the center of the length of the exhaust manifold, it is advantageous for the exhaust manifold to be efficiently cooled by the wind drawn in through the front gap, thereby improving the durability of the exhaust manifold and protecting peripheral equipment from heat damage. Furthermore, if an upper flange extending downward from the end of the curved upper cover and a lower flange extending upward from the end of the curved lower cover are formed, and a gap is provided between the upper ends of the upper and lower flanges, the upper and lower flanges will shield the exhaust manifold from radiant heat, thereby protecting peripheral equipment located behind the exhaust manifold from heat damage. Furthermore, since the wind flows toward the rear of the vehicle through the gap between the lower end of the upper flange and the upper end of the lower flange, it is advantageous for more wind to be drawn in through the gap between the front ends of the upper and lower covers, thereby increasing the cooling effect of the exhaust manifold by the wind and reducing radiant heat emitted from the exhaust manifold, thereby protecting peripheral equipment from heat damage.Furthermore, if the exhaust temperature sensor is located behind the exhaust manifold at a location where a linear flow of running air meets a flow of running air that curves inward in the vehicle width direction, the exhaust temperature sensor, which has been heated by the exhaust, can be efficiently cooled by the combined flow of running air, which is advantageous for improving the durability of the exhaust temperature sensor. Furthermore, if the upper cover and the lower cover are attached to multiple attachment portions provided on the exhaust manifold, respectively, and at least one attachment portion is provided on the cylinder head attachment flange or the exhaust pipe attachment flange, the number of attachment portions located between the exhaust manifold and the upper cover and the number of attachment portions located between the exhaust manifold and the lower cover can be reduced, which can smooth the flow of running air between the exhaust manifold and the upper cover and the lower cover, thereby improving the cooling effect of the running air on the exhaust manifold and improving the durability of the exhaust manifold. Furthermore, if the radiant heat emitted from the exhaust manifold is reduced, which is advantageous for protecting peripheral devices from heat damage.

[0007] 1 is a perspective view of an exhaust manifold cover according to an embodiment assembled to an exhaust manifold, as seen from the front and above of a vehicle. FIG. 1 is a plan view of FIG. 1. FIG. 2 is a bottom view of FIG. 1. FIG. 2 is a view as seen from an arrow A in FIG. 2. FIG. 2 is a view as seen from an arrow B in FIG. 2. FIG. 2 is a view as seen from an arrow C in FIG. 2. A cross-sectional view taken along line D-D in FIG. 2. FIG. 3 is a perspective view of an exhaust manifold according to an embodiment seen from above. FIG. 4 is a perspective view of an exhaust manifold according to an embodiment seen from below.

[0008] An exhaust manifold cover for a vehicle according to an embodiment of the present invention will now be described with reference to the drawings. In the drawings, arrow UP indicates the upper side of the vehicle, arrow FR indicates the front side of the vehicle, and arrow HL indicates the width direction of the vehicle. As shown in FIGS. 1 and 2 , an exhaust manifold cover 14 according to an embodiment of the present invention is a cover for an exhaust manifold 12 attached to a cylinder head 10 of a so-called longitudinally mounted engine 11, in which the rotational axis of the crankshaft is aligned along the longitudinal direction of the vehicle. The engine 11 is disposed in a front space (engine compartment) of the vehicle in front of the passenger compartment. In this embodiment, the engine 11 is a four-cylinder engine, and when the engine 11 is disposed in the vehicle, the cylinders are aligned in the longitudinal direction of the vehicle. Hereinafter, the up-down, front-rear, and left-right (width) directions of the engine 11 are defined based on the directions when the engine 11 is disposed in the vehicle. The exhaust manifold 12 is made of a metal material such as cast iron, carbon steel, or stainless steel, and as shown in FIG. 8, is arranged from the front to the rear of the vehicle and includes first, second, third, and fourth pipe bodies 16A, 16B, 16C, and 16D, which are connected to exhaust ports of the cylinder head 10, respectively, an EGR pipe body 16E, which is connected to an EGR port of the cylinder head 10 for returning exhaust gas to the intake flow path, a cylinder head mounting flange 18 provided at the inner ends of these pipe bodies in the vehicle width direction, an exhaust manifold 20 connected to the first, second, third, and fourth pipe bodies 16A, 16B, 16C, and 16D and the EGR pipe body 16E, and where the exhaust from the first, second, third, and fourth pipe bodies 16A, 16B, 16C, and 16D join together, and an exhaust pipe mounting flange 22 provided at the outer end of the exhaust manifold 20 in the vehicle width direction, to which an exhaust pipe 24 (see FIG. 2) is connected. That is, the first, second, third, and fourth pipes 16A, 16B, 16C, and 16D are connected to the exhaust ports of the respective cylinders. In this embodiment, the EGR pipe 16E is connected to the cylinder head 10 rearward of the rearmost cylinder.

[0009] The exhaust manifold 12 has a length along the vehicle's fore-and-aft direction, and the exhaust manifold 20 is located at a position forward of the longitudinal center of the exhaust manifold 12. An exhaust temperature sensor 26 that detects the temperature of the exhaust gas in the exhaust manifold 12 is located in the fourth pipe body 16D located at the rear end of the vehicle. Therefore, the exhaust temperature sensor 26 is located at a position rearward of the exhaust manifold 20. As shown in Figures 8 and 9, the exhaust manifold 12 is provided with multiple mounting portions for attaching the exhaust manifold cover 14. As shown in Figure 8, the mounting portions at the upper part of the exhaust manifold 12 include a first upper mounting portion 28A provided on the upper surface of the first pipe body 16A, a second upper mounting portion 28B provided on the cylinder head mounting flange 18 at the rear end of the vehicle, and a third upper mounting portion 28C provided on the upper part of the exhaust pipe mounting flange 22. As shown in FIG. 9, the lower mounting portion of the exhaust manifold 12 has a first lower mounting portion 30A provided on the underside of the fourth pipe body 16D, and second and third lower mounting portions 30B, 30C provided on the front and rear sides of the exhaust pipe mounting flange 22.

[0010] 1 to 6, the exhaust manifold cover 14 is formed from a steel plate such as an aluminum-plated steel plate, and has an upper cover 32 that covers the exhaust manifold 12 from above, and a lower cover 34 that covers it from below. As shown in Fig. 2, the upper cover 32 has an upper cover main body 36 located above the exhaust manifold 12, and an upper flange 38 bent downward from the outer and rear ends of the upper cover main body 36 in the vehicle width direction.

[0011] The upper cover body 36 has a shape in plan view that corresponds to the shape in plan view of the exhaust manifold 12 excluding the cylinder head mounting flange 18 and the exhaust pipe mounting flange 22. As shown in Fig. 2, the upper cover body 36 includes an upper cover front end 40 located in the front of the vehicle, an upper cover rear end 42 located in the rear of the vehicle, an upper cover inner portion 44 connecting an inner end of the upper cover front end 40 to an inner end of the upper cover rear end 42 in the vehicle width direction, and an upper cover outer portion 46 connecting an outer end of the upper cover front end 40 to an outer end of the upper cover rear end 42 in the vehicle width direction. In plan view, the upper cover front end 40 includes an upper first front end 40A located in the front of the first pipe 16A, and an upper second front end 40B connected to the upper first front end 40A, located in front of the exhaust manifold 20, and gradually displaced rearward as it reaches the outer side in the vehicle width direction. In a plan view, the upper cover rear end 42 is located rearward of the EGR pipe body 16E.

[0012] As shown in Figures 2 and 7, the upper cover inner portion 44 extends linearly in the vehicle longitudinal direction at a location above and outwardly of the cylinder head mounting flange 18 in the vehicle width direction. As shown in Figures 2 and 5, the upper cover outer portion 46 includes an upper cover outer front portion 46A, an upper cover outer intermediate portion 46B, and an upper cover outer rear portion 46C. The upper cover outer front portion 46A extends linearly in the vehicle longitudinal direction at a location above the exhaust pipe mounting flange 22 and is located outwardly of the vehicle width direction. The upper cover outer intermediate portion 46B is connected to the rear end of the upper cover outer front portion 46A and is located rearward of the exhaust manifold 20. The upper cover outer rear portion 46C is connected to the rear end of the upper cover outer intermediate portion 46B and gradually approaches the upper cover inner portion 44 as it extends rearward and is connected to the upper cover rear end 42. As shown in Figure 2, the front end of the upper cover outer front portion 46A is connected to the outer end of the upper second front end portion 40B in the vehicle width direction. The upper cover outer middle portion 46B and the upper cover outer rear portion 46C extend along a curve in a plan view.

[0013] As shown in Figures 4 and 6, the upper flanges 38 are provided to protrude downward from the upper cover outer intermediate portion 46B, the upper cover outer rear portion 46C, and the upper cover rear end 42, and the lower ends of the upper flanges 38 provided on the upper cover outer rear portion 46C and the upper cover rear end 42 are located at the same position in the up-down direction. As shown in Figure 2, the upper flanges 38 provided on the upper cover outer intermediate portion 46B and the upper cover outer rear portion 46C extend along a curve in a plan view. The upper cover rear end 42 is configured to include the upper flange 38 provided on this upper cover rear end 42.

[0014] As shown in FIG. 3, the lower cover 34 includes a lower cover main body 48 located below the exhaust manifold 12, and a lower flange 50 bent upward from the outer and rear ends of the lower cover main body 48 in the vehicle width direction.

[0015] The lower cover body 48 has a shape in a bottom view that corresponds to the shape of the exhaust manifold 12 excluding the cylinder head mounting flange 18 and the exhaust pipe mounting flange 22. As shown in Fig. 3, the lower cover body 48 includes a lower cover front end 52 located in the front of the vehicle, a lower cover rear end 54 located in the rear of the vehicle, a lower cover inner portion 56 connecting an inner end of the lower cover front end 52 to an inner end of the lower cover rear end 54 in the vehicle width direction, and a lower cover outer portion 58 connecting an outer end of the lower cover front end 52 to an outer end of the lower cover rear end 54 in the vehicle width direction. When viewed from the bottom, the lower cover front end 52 is configured with a lower first front end 52A that extends obliquely with respect to the fore-and-aft direction of the vehicle and exposes a portion of the first pipe 16A near the cylinder head mounting flange 18 downward, and a lower second front end 52B that is connected to the outer end of the lower first front end 52A in the vehicle width direction and is located forward of the exhaust manifold 20. The lower cover rear end 54 is located rearward of the EGR pipe body 16E when viewed from the bottom.

[0016] As shown in Figures 3 and 7 , the lower cover inner portion 56 extends linearly in the fore-and-aft direction of the vehicle at a location spaced downward and outward in the vehicle width direction from the cylinder head mounting flange 18 when viewed from the bottom. As shown in Figures 3 and 5 , the lower cover outer portion 58 includes a lower cover outer front portion 58A, a lower cover outer intermediate portion 58B, and a lower cover outer rear portion 58C. The lower cover outer front portion 58A extends linearly in the fore-and-aft direction of the vehicle at a location spaced inward in the vehicle width direction from the exhaust pipe mounting flange 22 and is located at the outermost position in the vehicle width direction. The lower cover outer intermediate portion 58B is connected to the rear end of the lower cover outer front portion 58A and is located rearward of the exhaust manifold 20. The lower cover outer rear portion 58C is connected to the rear end of the lower cover outer intermediate portion 58B and gradually approaches the lower cover inner portion 56 as it extends rearward, where it is connected to the lower cover rear end 54. The front end of the lower cover outer front portion 58A is connected to the end of the lower second front end portion 52B on the outer side in the vehicle width direction. The lower cover outer middle portion 58B and the lower cover outer rear portion 58C extend along a curve in bottom view.

[0017] As shown in Figures 4 and 6 , the lower flanges 50 protrude upward from the lower cover outer intermediate portion 58B, the lower cover outer rear portion 58C, and the lower cover rear end 54. The lower flanges 50 provided on the lower cover outer intermediate portion 58B and the lower cover outer rear portion 58C extend along a curve in a bottom view as shown in Figure 3. As shown in Figure 6 , a notch 60 is provided at the end of the lower flange 50 provided on the lower cover rear end 54 on the inner side in the vehicle width direction, and the lower cover rear end 54 is configured to include the lower flange 50 provided on the lower cover rear end 54. The upper ends of the lower flanges 50 provided on the lower cover outer rear portion 58C and the lower cover rear end 54 are located at the same position in the up-down direction, and as shown in Figures 4 and 6 , a gap S0 is secured between the upper ends of the lower flanges 50 provided on the lower cover outer rear portion 58C and the lower cover rear end 54 and the lower ends of the upper flanges 38 provided on the upper cover outer rear portion 46C and the upper cover rear end 42.

[0018] As shown in Figures 2 and 8, the upper cover 32 is attached to mounting portions 28A, 28B, and 28C located on the upper side of the exhaust manifold 12 with bolts B. As shown in Figures 3 and 9, the lower cover 34 is attached to mounting portions 30A, 30B, and 30C located on the upper side of the exhaust manifold 12 with bolts B. By attaching the upper cover 32 and the lower cover 34 to the exhaust manifold 12 in this manner, an upper air passage P1 extending in the fore-and-aft direction of the vehicle is formed between the upper cover 32 and an upper surface 1202 of the exhaust manifold 12, and a lower air passage P2 extending in the fore-and-aft direction of the vehicle is formed between the lower cover 34 and a lower surface 1204 of the exhaust manifold 12, as shown in Figure 7.

[0019] In this embodiment, as shown in Fig. 5, the distance d1 between the front end of the upper cover 32 and the front end of the lower cover 34 is greater than the distance d2 between the rear end of the upper cover 32 and the rear end of the lower cover 34 as shown in Fig. 6. In other words, as shown in Fig. 5, a front gap S1 having a vertical distance d1 is formed between the front end of the upper cover 32 and the front end of the lower cover 34, and as shown in Fig. 6, a rear gap S2 having a vertical distance d2 is formed between the rear end of the upper cover 32 and the rear end of the lower cover 34. Note that the distance d2 between the rear end of the upper cover 32 and the rear end of the lower cover 34 is the distance between the lower end of the upper flange 38 at the rear end of the upper cover 32 and the rear end of the lower cover main body 48 located below the notch 60. Furthermore, the length L1 of the front gap S1 in the vehicle width direction is greater than the length L2 of the rear gap S2 in the vehicle width direction.

[0020] Next, the effects of the embodiment of the present invention will be described. When a vehicle is running, exhaust gas heated by the operation of the engine 11 passes through the exhaust manifold 12 and is discharged into the exhaust pipe 24. The exhaust gas heats the exhaust manifold 12 to a high temperature of, for example, about 600°C to 700°C, causing radiant heat to be emitted from the exhaust manifold 12. However, this radiant heat is blocked by the upper cover 32 and the lower cover 34 that cover the exhaust manifold 12 from above and below, thereby suppressing thermal damage to peripheral equipment near the exhaust manifold 12.

[0021] Furthermore, the traveling wind flowing from the front of the vehicle toward the rear of the vehicle is introduced into the upper air passage P1 and the lower air passage P2 through a front gap S1 having a vertical distance d1 between the front end of the upper cover 32 and the front end of the lower cover 34. In this embodiment, in the front gap S1 near the cylinder head 10 of the upper air passage P1 and the lower air passage P2, the traveling wind flows linearly toward the rear of the vehicle, as indicated by reference symbol F1 in FIG. 2 . Furthermore, in the front gap S1 farther from the cylinder head 10 of the upper air passage P1 and the lower air passage P2, the curved upper flange 38 provided on the upper cover outer intermediate portion 46B and the curved lower flange 50 provided on the lower cover outer intermediate portion 58B cause the traveling wind to curve inward in the vehicle width direction while flowing toward the rear of the vehicle, as indicated by reference symbol F2 in FIG. 2 . Therefore, the traveling wind flowing linearly and the traveling wind flowing curved inward in the vehicle width direction merge at a location rearward of the exhaust collector 20. The combined airflow passes through the upper air passage P1 and the lower air passage P2 and is discharged from the rear gap S2 having a distance d2.

[0022] In this embodiment, the vertical distance d1 between the front end of the upper cover 32 and the front end of the lower cover 34 is greater than the vertical distance d2 between the rear end of the upper cover 32 and the rear end of the lower cover 34. This allows more airflow during travel to be taken in between the upper cover 32 and the upper surface 1202 of the exhaust manifold 12 and between the lower cover 34 and the lower surface 1204 of the exhaust manifold 12, which is advantageous for efficiently cooling the exhaust manifold 12 with the airflow. This is not only advantageous for improving the durability of the exhaust manifold 12, but also for reducing the cooling of the exhaust manifold 12, thereby reducing the radiant heat radiated from the exhaust manifold 12 and protecting peripheral equipment from heat damage. Furthermore, by reducing the vertical distance d2 between the rear end of the upper cover 32 and the rear end of the lower cover 34, it is possible to efficiently block the radiant heat radiated from the rear end of the exhaust manifold 12, which is advantageous for protecting peripheral equipment arranged near the rear end of the exhaust manifold 12 from heat damage.

[0023] Furthermore, in this embodiment, the length L1 of the front gap S1 in the vehicle width direction is formed to be greater than the length L2 of the rear gap S2 in the vehicle width direction, which is advantageous for taking in more traveling wind between the upper cover 32 and the upper surface 1202 of the exhaust manifold 12 and between the lower cover 34 and the lower surface 1204 of the exhaust manifold 12. Therefore, this is advantageous for increasing the cooling effect of the exhaust manifold 12 by the traveling wind, thereby improving the durability of the exhaust manifold 12, and is advantageous for protecting peripheral equipment from heat damage by reducing the radiant heat radiated from the exhaust manifold 12. Furthermore, by reducing the length L2 of the rear gap S2 in the vehicle width direction, it is possible to efficiently block radiant heat radiated from the rear end of the exhaust manifold 12, which is advantageous for protecting peripheral equipment arranged near the rear end of the exhaust manifold 12 from heat damage.

[0024] Furthermore, in this embodiment, the exhaust manifold 12 is provided at a location closer to the front of the vehicle than the center of the length of the exhaust manifold 12, which is advantageous in efficiently cooling the exhaust manifold 20 with the wind from the vehicle traveling through the front gap S1. This is therefore advantageous in improving the durability of the exhaust manifold 12 and protecting peripheral devices from heat damage.

[0025] Furthermore, in this embodiment, when the upper cover 32 is viewed from above and the lower cover 34 is viewed from below, the ends of the upper cover 32 and the lower cover 34 that are farther from the cylinder head 10 extend on an inclined curve that approaches the cylinder head 10 at a location rearward of the exhaust manifold 20, and the upper flange 38 that protrudes downward extends along the curved end of the upper cover 32, and the lower flange 50 that protrudes upward extends along the curved end of the lower cover 34, and a gap S0 is secured between the lower end of the upper flange 38 and the upper end of the lower flange 50. Therefore, the upper flange 38 and the lower flange 50 shield radiant heat from the exhaust manifold 12, which is advantageous in protecting peripheral devices arranged behind the exhaust manifold 12 from heat damage. Furthermore, since the traveling wind flows toward the rear of the vehicle through the gap S0 between the lower end of the upper flange 38 and the upper end of the lower flange 50, it is advantageous for taking in more traveling wind from the front gap S1 into the upper air passage P1 and the lower air passage P2, and the traveling wind flowing through the upper air passage P1 and the lower air passage P2 is smoothly guided toward the rear of the vehicle. Therefore, it is advantageous for increasing the cooling effect of the traveling wind on the exhaust manifold 12 to improve the durability of the exhaust manifold 12, and for protecting peripheral devices from heat damage by reducing the radiant heat emitted from the exhaust manifold 12.

[0026] Furthermore, in this embodiment, the exhaust temperature sensor 26 is located at a location rearward of the exhaust collection section 20, at a point where the traveling wind flowing in a straight line and the traveling wind flowing in a curved manner toward the inside of the vehicle width direction converge. This is advantageous for efficiently cooling the exhaust temperature sensor 26, which has been heated by the exhaust, by the confluent traveling wind, and is advantageous for increasing the durability of the exhaust temperature sensor 26.

[0027] Furthermore, in this embodiment, of the three mounting portions 28A, 28B, and 28C for the upper cover 32, two mounting portions 28B and 28C are provided on the cylinder head mounting flange 18 and the exhaust pipe mounting flange 22. Furthermore, of the three mounting portions 30A, 30B, and 30C for the lower cover 34, two mounting portions 30B and 30C are provided on the exhaust pipe mounting flange 22. The mounting portions 28B, 28C, 30B, and 30C provided on the cylinder head mounting flange 18 and the exhaust pipe mounting flange 22 are located outside the upper air passage P1 and the lower air passage P2 in the width direction of the passages. Therefore, it is possible to ensure a large passage area for the upper air passage P1 and the lower air passage P2, smooth the flow of the wind generated by running in the upper air passage P1 and the lower air passage P2, and increase the cooling effect of the exhaust manifold 12 by the wind generated by running, which is advantageous in improving the durability of the exhaust manifold 12, and it is also advantageous in protecting peripheral devices from heat damage by reducing the radiant heat emitted from the exhaust manifold 12.

[0028] In this embodiment, the exhaust manifold cover 14 is described as a cover for the exhaust manifold 12 attached to the cylinder head 10 of a vertically mounted engine 11, but the exhaust manifold cover of the present invention is of course also applicable to a cover for an exhaust manifold attached to a horizontally mounted engine in which the rotational axis of the crankshaft is aligned along the vehicle width direction.

[0029] REFERENCE SIGNS LIST 10 Cylinder head 11 Engine 12 Exhaust manifold 1202 Upper surface 1204 Lower surface 14 Exhaust manifold cover 16A, 16B, 16C, 16D First, second, third and fourth pipe bodies 16E EGR pipe body 18 Cylinder head mounting flange 20 Exhaust collecting portion 22 Exhaust pipe mounting flange 24 Exhaust pipe 26 Exhaust temperature sensor 28A, 28B, 28C First, second and third upper mounting portions 30A, 30B, 30C First, second and third lower mounting portions 32 Upper cover 34 Lower cover 36 Upper cover body 38 Upper flange 40 Upper cover front end 40A Upper first front end portion 40B Upper second front end portion 42 Upper cover rear end 44 Upper cover inner portion 46 Upper cover outer portion 46A Upper cover outer front portion 46B Upper cover outer middle portion 46C Upper cover outer rear portion 48 Lower cover main body 50 Lower flange 52 Lower cover front end 52A Lower first front end portion 52B Lower second front end portion 54 Lower cover rear end 56 Lower cover inner portion 58 Lower cover outer portion 58A Lower cover outer front portion 58B Lower cover outer middle portion 58C Lower cover outer rear portion 60 Notch S0 Gap S1 Front gap S2 Rear gap d1 Vertical distance d2 Vertical distance L1 Length in vehicle width direction L2 Length in vehicle width direction P1 Upper air passage P2 Lower air passage

Claims

1. A cover for a vehicle exhaust manifold having an upper cover that covers an exhaust manifold from above and a lower cover that covers it from below, wherein the vertical distance between a front end of the upper cover and a front end of the lower cover is greater than the vertical distance between a rear end of the upper cover and a rear end of the lower cover.

2. A cover for an exhaust manifold for a vehicle as described in claim 1, characterized in that a front gap is formed between the front end of the upper cover and the front end of the lower cover, a rear gap is formed between the rear end of the upper cover and the rear end of the lower cover, and the length of the front gap in the vehicle width direction is formed larger than the length of the rear gap in the vehicle width direction.

3. A cover for an exhaust manifold for a vehicle as described in claim 1 or 2, characterized in that the exhaust manifold comprises a plurality of pipe bodies attached to the cylinder head of a longitudinally mounted engine, and an exhaust collector where the plurality of pipe bodies come together and are attached to an exhaust pipe, has a length along the fore-and-aft direction of the vehicle, and the exhaust collector is provided at a location closer to the front of the vehicle than the center of the length of the exhaust manifold.

4. A cover for an exhaust manifold for a vehicle as described in claim 3, characterized in that, when the upper cover is viewed in plan and the lower cover is viewed from the bottom, the end of the upper cover away from the cylinder head and the end of the lower cover extend on an inclined curve that approaches the cylinder head as it reaches the rear of the vehicle at a location on the rear of the vehicle of the exhaust collection section, an upper flange that protrudes downwardly extends along the end of the upper cover that extends on the curve, a lower flange that protrudes upwardly extends along the end of the lower cover that extends on the curve, and a gap is provided between the lower end of the upper flange and the upper end of the lower flange.

5. The exhaust manifold cover for a vehicle according to claim 3, characterized in that an exhaust temperature sensor is provided in the exhaust manifold, and the exhaust temperature sensor is provided at a location rearward of the exhaust manifold.

6. The exhaust manifold cover for a vehicle as described in claim 3, characterized in that the exhaust manifold comprises a cylinder head mounting flange provided at the end of the multiple pipe bodies and an exhaust pipe connecting flange provided at the end of the exhaust collection section, the upper cover and the lower cover are each attached to a multiple mounting portions provided on the exhaust manifold, and at least one mounting portion of the multiple mounting portions for mounting the upper cover and at least one mounting portion of the multiple mounting portions for mounting the lower cover are provided on the cylinder head mounting flange or the exhaust pipe connecting flange.

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