Internal combustion engine

Abstract

The present invention provides an internal combustion engine that shields against noise and vibration while allowing the cylinder block markings to be visible from outside the engine cover. [Solution] In the internal combustion engine EG according to the present invention, the engine cover 3 covers almost the entire upper surface of the rocker cover 13, thereby sufficiently suppressing noise and vibration emitted from the engine body 1. Furthermore, the engine cover 3 is provided with a display confirmation window 312 that allows the display 113 provided on the cylinder block 11 to be viewed from outside the engine cover 3, thereby ensuring that the display 312 is visible from outside the engine cover 3.

Description

Technical Field

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

Background Art

[0002] As a conventional internal combustion engine provided with an engine cover, for example, the one described in Patent Document 1 below is known.

[0003] That is, a conventional internal combustion engine has a cylinder block that houses a piston, a cylinder head placed on top of the cylinder block, and a rocker cover placed on top of the cylinder head. An engine cover for suppressing (shielding) the propagation of sound vibrations generated by the internal combustion engine is provided on top of the rocker cover.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the engine cover provided in the conventional internal combustion engine has a limited area covered by the engine cover in order to make visible from above the internal combustion engine the display such as the engine model engraved on the cylinder block. For this reason, there still remains room for improvement in that it is difficult to sufficiently suppress the propagation of sound vibrations of the internal combustion engine.

[0006] On the other hand, if the area of the engine cover is enlarged, the display on the cylinder head will be covered by the engine cover. For this reason, a problem is caused in that it becomes difficult to visually confirm the display from the outside of the engine cover above the internal combustion engine.

[0007] Therefore, the present invention was devised in view of the technical problems of the conventional internal combustion engines, and aims to provide an internal combustion engine that allows the cylinder block markings to be visible from outside the engine cover while shielding the sound and vibration of the internal combustion engine. [Means for solving the problem]

[0008] In one aspect, the present invention provides an internal combustion engine comprising: a cylinder block having a marking visible from above; a cylinder head mounted on the upper part of the cylinder block; and a rocker cover mounted on the upper part of the cylinder head, wherein the engine cover covers the upper surface of the rocker cover so as to cover the marking, and the engine cover is provided penetrating vertically and has an opening that allows the marking to be viewed. [Effects of the Invention]

[0009] According to the present invention, the engine cover covers almost the entire upper surface of the rocker cover, and the engine cover is provided with an opening that allows the display to be seen. This makes it possible to sufficiently suppress the noise and vibration of the internal combustion engine while ensuring that the display can be seen from vertically above the internal combustion engine through the opening. [Brief explanation of the drawing]

[0010] [Figure 1] This is a perspective view of the internal combustion engine according to the present invention, viewed from a vertically upward angle to the right front. [Figure 2] This is a perspective view of the internal combustion engine according to the present invention, viewed from the left front and vertically upward. [Figure 3] This is a front view of an internal combustion engine according to the present invention. [Figure 4] This is a plan view of an internal combustion engine according to the present invention. [Figure 5] This figure shows an engine cover according to the present invention, where (a) is a top view, (b) is a front view, and (c) is a left side view. [Figure 6] Figure 5 shows the engine cover as viewed from the bottom, where (a) is a perspective view and (b) is a plan view. [Figure 7] Figure 4 is a plan view of the engine body with the engine cover removed, as shown in the internal combustion engine. [Modes for carrying out the invention]

[0011] Embodiments of the internal combustion engine according to the present invention will be described in detail below with reference to the drawings. In this embodiment, as with conventional examples, the internal combustion engine is shown as being applied to a turbocharged automobile engine (spark-ignition internal combustion engine).

[0012] (Configuration of an internal combustion engine) Figure 1 shows a perspective view of the internal combustion engine EG according to this embodiment, viewed from the right front and vertically upward. Figure 2 shows a perspective view of the internal combustion engine EG according to this embodiment, viewed from the left front and vertically upward. Figure 3 shows a front view of the internal combustion engine EG according to this embodiment. Figure 4 shows a plan view of the internal combustion engine EG according to this embodiment.

[0013] For example, as shown in Figures 1 to 4, the internal combustion engine EG according to this embodiment includes an engine body 1 mounted on a vehicle (not shown), an intake device 2 that guides intake air to the engine body 10, an exhaust pipe (not shown) that discharges exhaust gas generated in the engine body 1, and a turbocharger (not shown) provided in the exhaust passage of the exhaust pipe.

[0014] The engine body 1 comprises a cylinder block 11, a cylinder head 12 mounted on top of the cylinder block 11, a rocker cover 13 mounted on top of the cylinder head 12, and an engine cover 3 covering the top of the rocker cover 13. An oil pan 14 for storing engine oil is attached to the lower end of the cylinder block 11. A front cover 15 for housing the timing gear and timing chain is attached to the second side (left side) of the engine body 1, opposite to the flange portion 111 which will be described later.

[0015] The cylinder block 11 has a plurality of cylinders (not shown) arranged in a row inside. Further, on the first side portion (right side portion) of the cylinder block 11, a substantially flange-shaped flange portion 111 to which a gear case of a transmission (not shown) is connected is provided. The flange portion 111 has a planar inclined surface portion 112 that can be visually recognized from above (substantially vertically upward), and on this inclined surface portion 112, an indication 113 such as the type of the engine is indicated by engraving.

[0016] The cylinder head 12 has combustion chambers (not shown) corresponding to the respective cylinders (not shown) inside. An intake device 2 is connected to an intake port (not shown) that opens on the front end side of the cylinder head 12, and an exhaust pipe (not shown) is connected to an exhaust port (not shown) that opens on the rear end side of the cylinder head 12. The rocker cover 13 houses an intake camshaft (not shown), an exhaust camshaft (not shown), and cam sprockets (not shown) attached to the respective camshafts (not shown) inside.

[0017] The intake device 2 has, in series and integrally, a surge tank 21 that guides intake air to the intake port (not shown) and an intercooler 22 that is interposed between the surge tank 21 and the cylinder head 12 (the intake port) and cools the supercharged air compressed by the turbocharger (not shown). Thus, the intake device 2 is provided offset forward from the cylinder head 12 due to the intercooler 22 being interposed between the cylinder head 12 and the surge tank 21. As a result, a predetermined gap S corresponding to the depth of the intercooler 22 is provided between the cylinder head 12 and the surge tank 21 (see FIG. 7).

[0018] The surge tank 21 is generally formed in a cylindrical shape by a resin material, and integrally has a tank body 211 extending in the longitudinal direction and a cylindrical intake pipe connection portion 212 provided at the upstream end of the tank body 211. The downstream end of the tank body 211 facing the intercooler 22 is connected to the upstream end of the intercooler 22 through an arbitrary connecting means such as caulking. The intake pipe connection portion 212 is curved substantially at a right angle and is connected to an intake pipe 23 that wraps around from the rear of the engine body 1 through an intake pipe connection flange 213.

[0019] The intercooler 22 is generally formed in a rectangular block shape by a metal material with good heat dissipation properties such as aluminum. The intercooler 22 has an intake passage (not shown) and a refrigerant passage (not shown) that are adjacent to each other and partitioned inside, and cools the intake flowing through the intake passage (not shown) based on the heat exchange action of the refrigerant flowing through the refrigerant passage (not shown).

[0020] (Configuration of engine cover) FIG. 5 is a view showing the engine cover 3 according to the present embodiment, where (a) is a plan view, (b) is a front view, and (c) is a left side view. FIG. 6 is a view of the engine cover 3 shown in FIG. 5 viewed from the bottom side, where (a) is a perspective view and (b) is a plan view. FIG. 7 is a plan view of the engine body 1 showing a state where the engine cover 3 is removed in the internal combustion engine EG shown in FIG. 4.

[0021] As shown in Figures 5 and 6, the engine cover 3 is made of a sound-absorbing resin material and integrally comprises a cover body 31 that extends generally horizontally and covers the upper part of the rocker cover 13, and a plurality of (four in this embodiment) locking parts, namely the first locking part 321, the second locking part 322, the third locking part 323, and the fourth locking part 324, which are provided at the bottom of the cover body 31 and protrude toward the rocker cover 13. The engine cover 3 is fixed to the engine body 1 by engaging the first locking portion 321, the second locking portion 322, the third locking portion 323, and the fourth locking portion 324 with a plurality of locking portions (four in this embodiment) provided on the engine body 1 (rocker cover 13) and surge tank 21, such as the first locking portion 41, the second locking portion 42, the third locking portion 43, and the fourth locking portion 44, as shown in Figure 7.

[0022] The cover body 31 has a generally circular cap insertion hole 311 facing the oil filler cap OC which is screwed into the rocker cover 13, and a display confirmation window 312 which is located above (approximately vertically above) the indicator 113 of the cylinder block 11 and passes through the cover body 31 to allow visual inspection of the indicator 113, corresponding to the opening of the present invention. As is well known, the cap insertion hole 311 has an inner diameter larger than that of the oil filler cap OC, allowing the oil filler cap OC to be attached and detached from outside the engine cover 3.

[0023] The display confirmation window 312 is provided in the cover body 31 at a horizontal position perpendicular to the gap S between the cylinder head 12 and the surge tank 21. For example, as shown by the arrow in Figure 1, a line of sight V to the display 113 of the cylinder block 11 is secured by passing through the display confirmation window 312 and the gap S from above (approximately vertically above). The display confirmation window 312 is formed so that its plan view is generally rectangular, specifically a parallelogram, and has a first opposing side 312a and a second opposing side 312b as a pair of opposing sides facing each other in the vehicle's front-rear direction (depth direction of the engine cover 3), and a first hypotenuse 312c and a second hypotenuse 312d as a pair of hypotenuses that are connected non-perpendicular to the first and second opposing sides 312a and 312b and do not face the first and second opposing sides 312a and 312b perpendicularly. Furthermore, the first and second opposing sides 312a and 312b are set such that the horizontal distance between them, or the plane distance D, is set to a distance at which the frequency of the standing wave exceeds 2000 Hz, specifically to less than 42.5 mm.

[0024] The first locking portion 321 is provided in a recessed shape at the tip of the first boss portion 331, which is formed in a generally columnar shape at the front end of the cover body 31 and adjacent to the display confirmation window 312, and is composed of a concave elastic member embedded in an insert. The first boss portion 331 is provided adjacent to the first opposing side 312a and the first hypotenuse 312c of the display confirmation window 312 and protrudes generally vertically toward the rocker cover 13. In other words, the first boss portion 331 is configured as a side wall adjacent to the inner opening edge of the display confirmation window 312. The first locking portion 321 is then fixed in a locked state to the protruding first locking portion 41 erected on the upper end of the base end of the surge tank 21, by screwing it into an insert-shaped female thread portion (not shown) embedded in the upper end of the base end of the surge tank 21.

[0025] The second locking portion 322 is located at the front end of the cover body 31 and is arranged in parallel with the first boss portion 331 at a distance from it. It is provided in a recessed shape at the tip of the second boss portion 332, which is generally formed in a columnar shape, and is made of a concave elastic member embedded in an insert. The second boss portion 332, like the first boss portion 331, protrudes generally vertically toward the rocker cover 13. The second locking portion 322 is then fixed in a locked state to the protruding second locking portion 42 erected on the first bracket 51, such as by screwing it into the female threaded portion (not shown) of the first bracket 51 which is fixed to the upper end of the front end of the surge tank 21.

[0026] The third locking portion 323 is located on the opposite side of the cap insertion hole 311 in the cylinder row direction where cylinders (not shown) are lined up, and is provided in a recessed shape at the tip of the generally columnar third boss portion 333, and is composed of a concave elastic member embedded in an insert shape. The third boss portion 333 protrudes generally vertically toward the rocker cover 13 at a lower height than the first and second boss portions 331 and 332. The third locking portion 323 is fixed in a locked state to a protruding third locking portion 43 erected on the second bracket 52, such as by screwing it into the female thread portion (not shown) of the second bracket 52 attached to one end of the upper surface of the rocker cover 13 in the cylinder row direction.

[0027] The fourth locking portion 324 is positioned adjacent to the cap insertion hole 311 in the cylinder row direction where cylinders (not shown) are lined up, and is recessed in the tip of the fourth boss portion 334 provided on the periphery of the cap insertion hole 311, and is composed of a concave elastic member embedded in an insert shape. The fourth boss portion 334 is provided in a flange shape that extends along the outer peripheral edge of the bottom of the cover body 31, and, like the third boss portion 333, protrudes toward the rocker cover 13 at a lower height than the first and second boss portions 331 and 332. The fourth locking portion 324 is fixed in a locked state to a projection-shaped fourth locking portion 44 erected on the third bracket 53, such as by screwing it into the female thread portion (not shown) of the third bracket 53 attached to the other end of the upper surface of the rocker cover 13 in the cylinder row direction.

[0028] Furthermore, the engine cover 3 has a concave shape in the center of its bottom, and this concave central part is provided with multiple rectangular recesses 35 separated by multiple ribs 34. In this case, adjacent recesses 35 are set to be of different sizes, which suppresses vibration resonance of the engine body 1 and improves the sound absorption of the engine cover 3.

[0029] (Effects of this embodiment) In this embodiment, the internal combustion engine EG can sufficiently suppress noise and vibration emitted from the engine body 1 because the engine cover 3 covers almost the entire upper surface of the rocker cover 13. Furthermore, the engine cover 3 is provided with a display confirmation window 312, which is an opening that allows the display 113 provided on the cylinder block 11 to be viewed from outside the engine cover 3. This display confirmation window 312 ensures that the display 113 can be seen from outside the engine cover 3. Thus, in this embodiment, it is possible to achieve both sufficient suppression of noise and vibration emitted from the engine body 1 and visibility of the display 113 from outside the engine cover 3 through the display confirmation window 312.

[0030] Furthermore, according to this embodiment, the surge tank 21 constituting the intake passage is curved in a way that bypasses the outer circumference of the line of sight V, so as not to overlap with the line of sight V that reaches the display 113 of the cylinder block 11 by passing through the display confirmation window 312 and the gap S from above (approximately vertically above) the internal combustion engine EG in a top view (plan view). As a result, even if the intake passage is laid out to wrap around from the rear side of the internal combustion engine EG, the display 113 can be easily seen. Moreover, in this embodiment, because the surge tank 21 constituting the intake passage is provided to bypass the outside of the line of sight V, it is possible to make the inclination of the line of sight V relatively smaller compared to when the surge tank 21 constituting the intake passage is placed inside the line of sight V. As a result, interference between the line of sight V and other parts located in the engine compartment is suppressed, and the display 113 of the cylinder block 11 can be easily seen.

[0031] Furthermore, in this embodiment, the surge tank 21, which constitutes an intake passage curved to bypass the line of sight V, is connected to the cylinder head 12 with the intercooler 22 in between. Therefore, it is possible to secure a relatively large gap S through which the line of sight V passes between the curved portion (intake pipe connection portion 212) that bypasses the line of sight V and the cylinder head 12. This improves the visibility of the display 113 on the cylinder block 11 through the display confirmation window 312.

[0032] Furthermore, in this embodiment, the curved portion (intake pipe connection portion 212) of the surge tank 21, which curves to wrap around the side of the engine body 1, and the outer circumferential surface (slope portion 112) of the flange portion 111 of the cylinder block 11, on which the display 113 is provided, are in close proximity at the side end of the engine body 1. This makes it possible to reduce the inclination of the line of sight V, thereby improving the visibility of the display 113.

[0033] Furthermore, in this embodiment, a first boss portion 331 is provided on the inner opening edge of the display confirmation window 312 of the engine cover 3, which serves as a side wall extending toward the rocker cover 13. Therefore, this first boss portion 331 makes it possible to suppress the leakage of sound radiated from the engine body 1 to the outside through the gap (vertical gap) between the engine cover 3 and the rocker cover 13. This makes it possible to more effectively suppress the leakage of sound radiated from the engine body 1.

[0034] Furthermore, in this embodiment, the display confirmation window 312 has a rectangular (parallelogram) shape in plan view, and the planar distance D between the pair of first and second opposing sides 312a and 312b is set to a distance where the standing wave frequency is greater than 2000 Hz. In this way, by setting the planar distance D between the first and second opposing sides 312a and 312b of the display confirmation window 312 to a distance that avoids the frequency band of 1000 to 2000 Hz in which the engine body 1 generates loud noise, the generation of large standing waves can be suppressed.

[0035] In other words, in this embodiment, the plane distance D between the first and second opposing sides 312a and 312b of the display confirmation window 312 is set to less than 42.5 mm. With this configuration, the frequency of the standing wave becomes greater than 2000 Hz, making it possible to avoid the frequency band 1000 to 2000 Hz in which the engine body 1 generates a lot of noise, and thus suppressing the generation of large standing waves.

[0036] Furthermore, in this embodiment, the display confirmation window 312 has a parallelogram shape in plan view and has a pair of first and second opposing sides 312a, 312b and a pair of first and second hypotenuse sides 312c, 312d that are not perpendicular to the first and second opposing sides 312a, 312b. In this way, because the pair of first and second hypotenuse sides 312c, 312d are not perpendicular to the pair of first and second opposing sides 312a, 312b, the generation of large standing waves can be suppressed even when the frequency of standing waves is set to 2000 Hz or less for the plane distance D between the first and second opposing sides 312a, 312b.

[0037] The present invention is not limited to the configurations illustrated in the above embodiments, and can be freely modified according to, for example, the specifications of the internal combustion engine to which the present invention is applied.

[0038] In particular, the shape of the display confirmation window 312 is not limited to the parallelogram exemplified in the above embodiment, but any shape that allows confirmation of the display 113 on the cylinder block 11 can be adopted, such as a rectangular or circular shape.

[0039] Furthermore, the horizontal position of the display confirmation window 312 is not limited to being on the extension of the display 113 in the vertical direction. It may also be configured so that the display 113 can be confirmed by a line of sight V directed diagonally downward from the display confirmation window 312. [Explanation of Symbols]

[0040] 1…Engine body 1 11…Cylinder block 111...Flange section 112... Sloping section (outer surface) 113…display 12…Cylinder head 13... Rocker cover 2…Intake system 21… Surge tank (intake passage) 212... Intake pipe connection 22... Intercooler 23…Intake pipe 3…Engine cover 312... Display confirmation window (opening) 312a... First opposite side (a pair of opposite sides) 312b... Second opposite side (a pair of opposite sides) 312c...First hypotenuse (a pair of hypotenuses) 312d...Second hypotenuse (a pair of hypotenuses) 331...First boss section (side wall) EG... Internal combustion engine V… Gaze S... Gap D… Distance between planes

Claims

1. An internal combustion engine comprising a cylinder block having a display that can be seen from above, a cylinder head mounted on top of the cylinder block, and a rocker cover mounted on top of the cylinder head, An engine cover that covers the upper surface of the rocker cover so as to cover the aforementioned display, The engine cover is provided with an opening that penetrates vertically and allows the display to be seen, An internal combustion engine.

2. An internal combustion engine according to claim 1, It is arranged to bypass the side of the internal combustion engine and has an intake passage connected to the cylinder head, The intake passage is curved in such a way as to bypass the line of sight in the direction of line of sight from above the internal combustion engine, through the opening, to the display, so as not to overlap with the line of sight. Internal combustion engine.

3. An internal combustion engine according to claim 2, A turbocharger installed on the exhaust side, An intercooler connected to the side of the cylinder head, which cools the supercharged air compressed by the turbocharger, Equipped with, The intake passage is connected to the intercooler and, via the intercooler, is connected to the cylinder head. Internal combustion engine.

4. An internal combustion engine according to claim 3, The aforementioned marking is provided on the outer circumferential surface of the flange portion provided at the side end of the cylinder block. Internal combustion engine.

5. An internal combustion engine according to claim 1, The engine cover has a side wall extending toward the rocker cover side at the inner opening edge of the opening. Internal combustion engine.

6. An internal combustion engine according to claim 5, The aforementioned opening is formed such that it has a rectangular shape when viewed from above. The plane distance between a pair of opposing sides in the aforementioned opening is set to a distance at which the frequency of the standing wave is greater than 2000 Hz. Internal combustion engine.

7. An internal combustion engine according to claim 6, The aforementioned plane-to-plane distance is set to less than 42.5 mm. Internal combustion engine.

8. An internal combustion engine according to claim 5, The aforementioned opening is formed such that its shape in plan view is a parallelogram. The opening has a pair of opposing sides and a pair of slanted sides that are connected to the opposing sides at a non-right angle and do not face each other perpendicularly. Internal combustion engine.

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