Internal combustion engine

Abstract

To prevent oil leaking from between a cylinder head and a head cover from exerting adverse effect.SOLUTION: An internal combustion engine 1 includes a cylinder head 2, a rocker cover 4 covering an upper surface of the cylinder head 2, and a downstream side third duct 17 located below a mating surface 11 of the cylinder head 2 and the rocker cover 4. The downstream side third duct 17 is positioned above an alternator 9 installed on the internal combustion engine 1, and has an oil receiver 21 which can receive oil dropped from the mating surface 11.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to an internal combustion engine.

Background Art

[0002] Patent Document 1 discloses an internal combustion engine in which a drain part is integrally formed in a gasket body that forms a main part of an exhaust manifold gasket interposed between a cylinder head and an exhaust manifold. The drain part extends into a space where a head cover and a secondary air distribution pipe are close to each other. In the internal combustion engine of this Patent Document 1, oil that leaks out from between the cylinder head and the head cover and drips down falls onto the drain part.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the internal combustion engine of such Patent Document 1, in order to receive oil that leaks out from between the cylinder head and the head cover and drips down, it is necessary to extend a drain part from the manifold gasket. Further, in the internal combustion engine of Patent Document 1, there is a risk that the oil that has fallen from the drain part drips onto parts located below the drain part.

[0005] That is, there is room for further improvement in the internal combustion engine so that oil that leaks out from between the cylinder head and the head cover and drips down does not have an adverse effect.

Means for Solving the Problems

[0006] The internal combustion engine of the present invention comprises a cylinder head, a rocker cover covering the upper surface of the cylinder head, and an intake duct having a lower mating surface portion located below the mating surface between the cylinder head and the rocker cover, wherein the lower mating surface portion is located above a predetermined high-temperature component and has a recess capable of receiving oil dripping from the mating surface. [Effects of the Invention]

[0007] The internal combustion engine of the present invention can prevent oil from coming into contact with high-temperature components, even if oil leaks and drips from the mating surface. [Brief explanation of the drawing]

[0008] [Figure 1] A schematic diagram illustrating the general configuration of an internal combustion engine to which the present invention is applied. [Figure 2] A schematic diagram illustrating the intake system of an internal combustion engine to which the present invention is applied. [Figure 3] A perspective view of the downstream third duct of an internal combustion engine to which the present invention is applied. [Figure 4] An explanatory diagram showing an enlarged view of section A in Figure 1. [Figure 5] This is an explanatory diagram schematically showing a cross-section along line BB in Figure 4. [Modes for carrying out the invention]

[0009] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0010] Figure 1 is a schematic diagram illustrating the general configuration of an internal combustion engine 1 to which the present invention is applied. Figure 2 is a schematic diagram illustrating the general configuration of the intake system 8 of the internal combustion engine 1 to which the present invention is applied. Figure 3 is a perspective view of the downstream third duct 17 of the internal combustion engine 1 to which the present invention is applied. Figure 4 is an enlarged explanatory diagram of section A in Figure 1, illustrating the main parts of the internal combustion engine 1 to which the present invention is applied. Figure 5 is a schematic explanatory diagram illustrating a cross-section along line BB in Figure 4, illustrating the internal combustion engine 1 as viewed from the crankshaft axis direction.

[0011] As shown in Figure 1, the internal combustion engine 1 is, for example, an in-line multi-cylinder internal combustion engine and includes a cylinder head 2, a cylinder block 3 attached to the lower part of the cylinder head 2, a rocker cover 4 covering the upper surface of the cylinder head 2, an oil pan 5 attached to the lower part of the cylinder block 3, and a front cover 6 covering the front of the internal combustion engine body 7. The cylinder head 2, cylinder block 3, rocker cover 4, and oil pan 5 constitute the internal combustion engine body 7.

[0012] Furthermore, the internal combustion engine 1 includes an intake system 8 connected to the cylinder head 2, and an alternator 9 to which the rotation of the crankshaft (not shown) of the internal combustion engine 1 is transmitted via a belt (not shown). The alternator 9 corresponds to a predetermined high-temperature component attached to the internal combustion engine 1.

[0013] The cylinder head 2 has an intake port (not shown) for supplying intake air to the combustion chamber (not shown) and an exhaust port (not shown) for discharging exhaust gas from the combustion chamber (not shown).

[0014] The cylinder block 3 has a number of cylinders (not shown) corresponding to the number of cylinders.

[0015] The rocker cover 4 is made of a synthetic resin material such as polyamide, etc., and is fixed to the upper surface of the cylinder head 2 with bolts (not shown) via a gasket (not shown). The mating surface 11 between the upper surface of the cylinder head 2 and the rocker cover 4 is located above the intake system 8 in the vertical direction of the internal combustion engine 1 (the vertical direction in FIG. 1).

[0016] The oil pan 5 is made of a metal material such as an aluminum alloy, etc., and constitutes a crankcase (not shown) in which a crankshaft (not shown) is accommodated together with the cylinder block 3.

[0017] The front cover 6 is made of a synthetic resin material such as polyamide, etc., and is liquid-tightly attached to the internal combustion engine body 7 so as to cover the front surface of the internal combustion engine body 7.

[0018] As shown in FIGS. 1 and 2, the intake system 8 has an air cleaner 12, an upstream intake duct 13 located upstream of the air cleaner 12, and a downstream intake duct 14 located downstream of the air cleaner 12, and supplies intake air to the internal combustion engine 1. The upstream intake duct 13 and the downstream intake duct 14 are made of a synthetic resin material such as polyamide, etc.

[0019] The downstream intake duct 14 is a cylindrical duct, and has a downstream first duct 15, a downstream second duct 16, and a downstream third duct 17 as a lower part of the mating surface.

[0020] In the downstream intake duct 14, the downstream first end 15a on the downstream side in the intake air flow direction is connected to the cylinder head 2 via a throttle chamber (not shown) and an intake manifold (not shown), and the upstream first end 15b on the upstream side in the intake air flow direction is connected to the downstream third end 17a of the downstream third duct 17.

[0021] The downstream second duct 16 is, for example, a cylindrical member. In the downstream second duct 16, the downstream second end portion 16a on the downstream side in the intake air flow direction is connected to the upstream third end portion 17b of the downstream third duct 17, and the upstream second end portion 16b on the upstream side in the intake air flow direction is connected to the air cleaner 12.

[0022] The downstream second end portion 16a of the downstream second duct 16 is located above the upstream first end portion 15b of the downstream first duct 15 in the vertical direction of the internal combustion engine 1. That is, the upstream first end portion 15b of the downstream first duct 15 is located below the downstream second end portion 16a of the downstream second duct 16 in the vertical direction of the internal combustion engine 1.

[0023] The downstream third duct 17 is obtained, for example, by joining a pair of downstream third duct members in a half-split shape by vibration welding or the like.

[0024] In the downstream third duct 17, the downstream third end portion 17a on the downstream side in the intake air flow direction is connected to the upstream first end portion 15b of the downstream first duct 15, and the upstream third end portion 17b on the upstream side in the intake air flow direction is connected to the downstream second end portion 16a of the downstream second duct 16. The downstream third duct 17 is arranged to be located above the alternator 9 in the vertical direction of the internal combustion engine 1.

[0025] The downstream third duct 17 is, for example, an eccentric pipe joint, and as shown in FIGS. 1 and 3, it connects the opposing downstream first duct 15 and downstream second duct 16.

[0026] [[ID=,20]]The downstream third duct 17 has a curved pipe formed such that the axis (pipe center) C1 at the downstream third end portion 17a does not coincide with the axis (pipe center) C2 at the upstream third end portion 17b. When there are no layout constraints, the shape of the downstream third duct 17 may be formed in a straight line such that the axis (pipe center) C1 at the downstream third end portion 17a coincides with the axis (pipe center) C2 at the upstream third end portion 17b.

[0027] In the assembled state, the downstream third duct 17 has its downstream third end 17a positioned lower than its upstream third end 17b in the vertical direction of the internal combustion engine 1. In the cylinder row direction of the internal combustion engine 1 (left-right direction in Figure 1), the downstream third end 17a is positioned lower in the vertical direction of the internal combustion engine 1.

[0028] Furthermore, as shown in Figures 3 to 5, the downstream third duct 17 has an oil receiving portion 21 formed on its outer surface as a recess capable of receiving oil dripping from the mating surface 11 between the upper surface of the cylinder head 2 and the rocker cover 4. The thick arrows in Figures 4 and 5 schematically represent the flow of oil dripping from the mating surface 11.

[0029] The oil receiving portion 21 is formed to overlap with the entire area where the mating surface 11 and the alternator 9 overlap in a plan view or side view of the internal combustion engine 1. The oil receiving portion 21 is formed to be longer than the area where the mating surface 11 and the alternator 9 overlap in the cylinder row direction of the internal combustion engine 1. Furthermore, the oil receiving portion 21 is formed so that both ends along the cylinder row direction of the internal combustion engine 1 are located outside the area where the mating surface 11 and the alternator 9 overlap.

[0030] The oil receiving portion 21 is formed by a rib 22, which is a protruding ridge provided on the outer circumferential surface of the downstream third duct 17. More specifically, the oil receiving portion 21 is an oil-receiving recess composed of the rib 22 and the outer surface of the downstream third duct 17. The rib 22 has an L-shaped cross-section and forms the oil receiving portion 21 with the outer surface of the downstream third duct 17 having a roughly C-shaped cross-section.

[0031] The rib 22 is provided in the downstream third duct 17 so as to extend along the direction of the cylinder row of the internal combustion engine 1 when the intake system 8 is attached to the cylinder head 2. In other words, the rib 22 is provided in the downstream third duct 17 which is arranged along the side surface of the internal combustion engine 1 so as to extend along the direction of the cylinder row of the internal combustion engine 1.

[0032] The rib 22 is provided on the downstream third duct 17 so as to be located on the side of the internal combustion engine 1 rather than the point where oil drips from the downstream third duct 17 when viewed in the axial direction of the crankshaft. This is because the downstream third duct 17 is positioned so that, when viewed in the axial direction of the crankshaft, the oil drips onto a curved surface that is located on the lower side in the vertical direction of the internal combustion engine 1 as it approaches the internal combustion engine 1.

[0033] Furthermore, the ribs 22 may be provided on both sides of the position where oil from the downstream third duct 17 drips, when viewed in the axial direction of the crankshaft. In other words, the oil receiving portion 21 may be formed on both sides of the position where oil from the downstream third duct 17 drips.

[0034] The rib 22 is fixed separately to the downstream third duct member of the downstream third duct 17, for example, by welding. Alternatively, the rib 22 may be formed integrally with the downstream third duct member.

[0035] In Figures 3 and 5, reference numeral 23 indicates the portion where the flanges of a pair of halved downstream third duct members have been welded together by vibration welding or the like.

[0036] Furthermore, as shown in Figure 5, the internal combustion engine 1 is mounted in the vehicle tilted toward the intake port side, which is the side where the intake system 8 is located, when viewed in the axial direction of the crankshaft. In other words, the mating surface 11 between the upper surface of the cylinder head 2 and the rocker cover 4 is located lower in the vertical direction of the internal combustion engine 1 as it is on the side where the intake system 8 is located. That is, the downstream third duct 17 is tilted such that the surface (curved surface) that receives oil dripping from the mating surface 11 is located lower in the vertical direction of the internal combustion engine 1 as it is on the inside, which is the side of the internal combustion engine 1 when viewed in the axial direction of the crankshaft.

[0037] Therefore, the oil receiving portion 21 is formed on the inside, which is on the side of the internal combustion engine 1 when viewed in the axial direction of the crankshaft, compared to the position where the oil dripped.

[0038] In such an internal combustion engine 1, if oil leaks from the mating surface 11 between the upper surface of the cylinder head 2 and the rocker cover 4, the oil can be received by the oil receiving portion 21 formed on the outer circumferential surface of the downstream third duct 17, as shown in Figures 4 and 5. In other words, the internal combustion engine 1 can receive oil dripping from the mating surface 11 above the alternator 9 at the oil receiving portion 21 to a position offset from the alternator 9 in the cylinder row direction of the internal combustion engine 1.

[0039] Therefore, even if oil leaks and drips from the mating surface 11 of the internal combustion engine 1, it is possible to suppress the dripping oil from splashing onto the alternator 9, and thus prevent the oil leaking from the mating surface 11 from adversely affecting the alternator 9.

[0040] Furthermore, in more detail, the internal combustion engine 1 has the following positional relationship between the alternator 9 and the oil receiving section 21.

[0041] In other words, the alternator 9 is positioned such that one end 9a, located on one end side in the cylinder row direction of the internal combustion engine 1, is below the mating surface 11, and the other end 9b, located on the other end side in the cylinder row direction of the internal combustion engine 1, is positioned so as not to overlap with the mating surface 11 in a plan view or side view of the internal combustion engine 1. The oil receiving portion 21 has one end 21a on the cylinder row side of the internal combustion engine 1 located below the mating surface 11, and the other end 21b on the cylinder row side of the internal combustion engine 1 is positioned so as not to overlap with the mating surface 11 in a plan view or side view of the internal combustion engine 1. Furthermore, the oil receiving portion 21 is formed such that, in a plan view or side view of the internal combustion engine 1, one end 21a is located closer to one end of the internal combustion engine 1 than one end 9a of the alternator 9, so as not to be located below (directly below) one end 21a of the oil receiving portion 21. Here, one end of the internal combustion engine 1 refers to the end of the internal combustion engine body 7 opposite to the front surface to which the front cover 6 is attached.

[0042] This ensures that even if oil leaks and drips from the mating surface 11 of the internal combustion engine 1, the oil that drips onto the alternator 9 will not splash onto it.

[0043] Although specific embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention.

[0044] For example, the oil receiving portion 21 may be formed by a groove formed on the outer surface of the downstream intake duct 14.

[0045] For example, the downstream intake duct 14 may be formed as a duct with a rectangular cross-section. In this case, if the surface of the downstream third duct 17 that receives oil dripping from the mating surface 11 is inclined when viewed in the axial direction of the crankshaft, a rib 22 may be provided on the inclined side to form an oil receiving portion 21. Alternatively, in this case, the downstream third duct 17 may have ribs 22 on both sides of the surface that receives oil dripping from the mating surface 11 when viewed in the axial direction of the crankshaft.

[0046] For example, the present invention is also applicable to a V-type internal combustion engine in which an exhaust duct is connected to the inside of the bank and an intake duct is connected to the outside of the bank. In this case, the mating surface between the cylinder head and the rocker cover in one bank and the mating surface between the cylinder head and the rocker cover in the other bank are located lower in the vertical direction of the V-type internal combustion engine as the outer side, which is the intake duct side, approaches the intake duct. Therefore, similar to the case where an in-line multi-cylinder internal combustion engine is mounted tilted towards the intake port side when viewed in the axial direction of the crankshaft, the intake duct can be provided with ribs in the portion located above high-temperature components such as the alternator, thereby preventing oil dripping from above from reaching these high-temperature components. [Explanation of Symbols]

[0047] 1…Internal combustion engine 2…Cylinder head 3…Cylinder block 4… Rocker cover 5… Oil pan 6…Front cover 7... Internal combustion engine body 8…Intake system 9... Alternator 9a...One end 9b...Other end 11…Mating surface 12... Air cleaner 14… Downstream intake duct 15…Downstream first duct 15a...Downstream first end 15b...Upstream first end 16…Downstream second duct 16a...Downstream second end 16b...Upstream second end 17…Downstream third duct 17a…Downstream third end 17b...Upstream third end 21… Oil receiving section 21a...One end 21b...Other end 22... Rib

Claims

1. The system comprises a cylinder head, a rocker cover covering the upper surface of the cylinder head, and an intake duct having a lower mating surface portion located below the mating surface between the cylinder head and the rocker cover. The lower part of the mating surface is located above a predetermined high-temperature component attached to the internal combustion engine, and is characterized by having a recess capable of receiving oil dripping from the mating surface.

2. The internal combustion engine according to claim 1, characterized in that the recess is formed to overlap with the entire area in which the mating surface and the high-temperature component overlap when viewed in plan of the internal combustion engine.

3. The internal combustion engine according to claim 1, characterized in that the recess is formed by a protruding rib provided on the outer circumferential surface of the lower part of the mating surface of the intake duct.

4. The internal combustion engine according to claim 3, characterized in that the ribs are formed in the lower part of the mating surface arranged along the side surface of the internal combustion engine so as to extend along the direction of the cylinder row of the internal combustion engine.

5. The internal combustion engine according to claim 3 or 4, characterized in that the above-mentioned ribs are fixed to the lower part of the mating surface by welding.

6. The internal combustion engine according to claim 1, characterized in that the above-mentioned high-temperature component is an alternator.

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