Internal combustion engine

Abstract

To enable visual check when inspecting a portion where three members that are a cylinder block, a cylinder head and a chain case are joined.SOLUTION: An internal combustion engine side mounting bracket 6 is mounted to an internal combustion engine body 8 astride a cylinder head 2 and a cylinder block 3 on an outer side of an outer peripheral edge of a front cover 5. An air gap 22 that enables visual recognition of a portion where the three members that are the cylinder head 2, the cylinder block 3 and the front cover 5 are joined is formed between the internal combustion engine side mounting bracket 6 and the internal combustion engine body 8.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an internal combustion engine mounted on a vehicle.

Background Art

[0002] For example, Patent Document 1 discloses an internal combustion engine in which a chain case (front cover) is connected to the end faces of a cylinder block and a cylinder head via a liquid gasket.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In an internal combustion engine, it is important to visually check for the presence or absence of leakage (seepage) of lubricating oil at the portion where the cylinder block, cylinder head, and chain case meet during assembly or regular inspections.

[0005] However, in Patent Document 1, there is a possibility that the visual inspection of the portion where these three members meet cannot be performed due to the components attached near the portion where these three members meet. In Patent Document 1, no consideration is given to visually inspecting the portion where the cylinder block, cylinder head, and chain case meet during inspections or the like.

[0006] That is, there is room for further improvement in the internal combustion engine so that the portion where the cylinder block, cylinder head, and chain case meet can be visually inspected during inspections.

Means for Solving the Problems

[0007] The internal combustion engine includes a mounting member that is attached to the internal combustion engine body across the cylinder head and the cylinder block outside the outer peripheral edge of the front cover, and a visible gap is formed between the mounting member and the internal combustion engine body at the portion where the three members of the cylinder head, the cylinder block, and the front cover meet.

Effect of the Invention

[0008] Since the internal combustion engine has a gap, the state of the portion where the three members of the cylinder head, the cylinder block, and the front cover meet can be easily visually confirmed.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiment for Carrying Out the Invention

[0010] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In each figure, the X-axis is the axis along the longitudinal direction of the internal combustion engine 1 (the axis parallel to the central axis of the crankshaft 19 of the internal combustion engine 1), the Y-axis is the axis along the left-right direction (the width direction of the internal combustion engine) of the internal combustion engine 1, and the Z-axis is the axis along the up-down direction of the internal combustion engine 1 (the axis parallel to the cylinder axis L1 of the internal combustion engine 1). That is, the X-axis is the axis along the cylinder bank direction of the internal combustion engine 1 or the internal combustion engine body 8 (described later). Further, the Y-axis is the axis along the width direction of the internal combustion engine body 8.

[0011] FIG. 1 is an explanatory view schematically showing the schematic configuration of the internal combustion engine 1 to which the present invention is applied.

[0012] 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 cam bracket 4 attached to the upper part of the cylinder head 2, a front cover 5 covering the front surface of the internal combustion engine body 8, and an internal combustion engine side mount bracket 6 as a metal mount bracket or attachment member located on the front surface of the front cover 5.

[0013] Note that the reference numeral 7 in FIG. 1 is a vehicle body side mount bracket fixed to the vehicle body side. The cylinder head 2, the cylinder block 3, and the cam bracket 4 constitute the internal combustion engine body 8. Therefore, the front cover 5 covers the end surface 8a on one end side in the cylinder bank direction of the internal combustion engine body 8.

[0014] The cylinder head 2 is, for example, a casting made of a metal material such as an aluminum alloy, and an intake port (not shown) for supplying intake air to the combustion chamber (not shown) and an exhaust port (not shown) for discharging exhaust from the combustion chamber (not shown) are formed.

[0015] The cylinder block 3 is, for example, a casting made of a metal material such as an aluminum alloy, and a number of cylinders (not shown) corresponding to the number of cylinders are formed.

[0016] The cam bracket 4 is made of a metal material such as an aluminum alloy, etc., and rotatably supports a camshaft (not shown) together with the cylinder head 2.

[0017] The front cover 5 is made of a synthetic resin material such as polyamide, etc., and is liquid-tightly attached to the internal combustion engine body 8 so as to cover the front surface of the internal combustion engine body 8. More specifically, the front cover 5 is attached to the front surface of the cylinder block 3, the front surface of the cylinder head 2, the front surface of the cam bracket 4, etc. by bolts 9 (refer to FIG. 5 described later) with a sealing material (not shown) interposed therebetween. In other words, the front cover 5 is attached to the internal combustion engine body 8 so as to cover the end surfaces of one end side of the cylinder block 3 and the cylinder head 2 in the crankshaft axial direction, that is, the end surface 8a of one end side in the cylinder row direction of the internal combustion engine body 8.

[0018] The front cover 5 has a shallow dish shape and forms a space between it and the front surface of the internal combustion engine body 8 which is the end surface 8a of one end side in the cylinder row direction of the internal combustion engine body 8. In this space, a cranksprocket (not shown) fixed to the crankshaft 19 (refer to FIG. 2) and a camssprocket (not shown) fixed to the front end of a camshaft (not shown) are accommodated. A timing chain (not shown) for rotational power transmission is wound around these cranksprocket and camssprocket. That is, the space formed between the front cover 5 and the internal combustion engine body 8 is an environment having a timing chain for oil lubrication. The space formed between the front cover 5 and the internal combustion engine body 8 is liquid-tight with respect to the outside because the space between the front cover 5 and the internal combustion engine body 8 is liquid-tightly sealed with a sealing material not shown.

[0019] As shown in FIG. 2, the front cover 5 is formed with a crankshaft through hole 14, a bolt through hole 15, and a gauge insertion port 50. FIG. 2 is a front view of the internal combustion engine 1 to which the internal combustion engine side mount bracket 6 is attached.

[0020] The crankshaft through-hole 14 is for the crankshaft 19 to pass through, and its periphery is sealed in a liquid-tight manner.

[0021] The bolt through-holes 15 are for bolts 9 (refer to FIG. 5 described later) for fixing the front cover 5 to the internal combustion engine body 8 to pass through, and a plurality (a large number) of them are formed on the outer peripheral edge of the front cover 5. The outer peripheral edge of the front cover 5 is sealed in a liquid-tight manner over the entire circumference by an annular outer peripheral edge sealing material (not shown) as a sealing member. The outer peripheral edge sealing material is located on the inner peripheral side of the bolt through-holes 15.

[0022] The gauge insertion port 50 is a hole formed through the upper part of the front cover 5 into which an oil level gauge (not shown) is inserted.

[0023] The internal combustion engine side mount bracket 6 is attached to the end face 8a on one end side in the cylinder bank direction of the internal combustion engine body 8 without contacting the front cover 5. The internal combustion engine side mount bracket 6 is a casting made of a metal material such as an aluminum alloy, and is a member for attaching the internal combustion engine body 8 (internal combustion engine 1) to the vehicle.

[0024] The internal combustion engine side mount bracket 6 is attached to the end faces on one end side of the cylinder head 2 and the cylinder block 3 by six bolts 31, namely, the first bolt 31a to the sixth bolt 31f. The bolts 31 pass through the bolt boss portions 32 of the internal combustion engine side mount bracket 6.

[0025] The internal combustion engine side mount bracket 6 is formed such that the length along the width direction of the internal combustion engine body 8 is longer than that of the front cover 5. The internal combustion engine side mount bracket 6 overlaps and covers a part of the outer surface of the front cover 5 with a predetermined gap in the cylinder bank direction of the internal combustion engine body 8, and is attached to the internal combustion engine body 8. That is, the internal combustion engine side mount bracket 6 is attached to the internal combustion engine body 8 so as not to contact the front cover 5.

[0026] As shown in Fig. 2, the internal combustion engine side mounting bracket 6 straddles the outside of the front cover 5 in the width direction of the front cover 5 (the direction along the Y-axis) and is fixed to the internal combustion engine body 8 on both sides of the front cover 5. That is, the internal combustion engine side mounting bracket 6 is attached to the internal combustion engine body 8 outside the outer peripheral edge of the front cover 5.

[0027] For the internal combustion engine side mounting bracket 6, the upper edge portion in the vertical direction along the cylinder axis L1 of the internal combustion engine 1 is fixed to the internal combustion engine body 8 by the first bolt 31a to the third bolt 31c. For the internal combustion engine side mounting bracket 6, the lower edge portion in the vertical direction along the cylinder axis L1 of the internal combustion engine 1 is fixed to the internal combustion engine body 8 by the fourth bolt 31d to the sixth bolt 31f.

[0028] Specifically, for the upper edge portion of the internal combustion engine side mounting bracket 6, both end portions in the width direction of the internal combustion engine body 8 are fixed to the internal combustion engine body 8 by the first bolt 31a and the third bolt 31c outside the front cover 5. Also, for the upper edge portion of the internal combustion engine side mounting bracket 6, the central portion in the width direction of the internal combustion engine body 8 is fixed to the internal combustion engine body 8 by the second bolt 31b passing through the front cover 5.

[0029] For the lower edge portion of the internal combustion engine side mounting bracket 6, both end portions in the width direction of the internal combustion engine body 8 are fixed to the internal combustion engine body 8 by the fourth bolt 31d and the sixth bolt 31f outside the front cover 5. Also, for the lower edge portion of the internal combustion engine side mounting bracket 6, the central portion in the width direction of the internal combustion engine body 8 is fixed to the internal combustion engine body 8 by the fifth bolt 31e passing through the front cover 5.

[0030] As shown in FIGS. 2 to 4, the internal combustion engine side mount bracket 6 has six bolt bosses 32, namely, a first bolt boss portion 32a to a sixth bolt boss portion 32f. FIG. 3 is a rear view of the internal combustion engine side mount bracket 6. FIG. 4 is a perspective view of the internal combustion engine side mount bracket 6 viewed from the rear side (back side). The internal combustion engine side mount bracket 6 does not contact the front cover 5, and these six bolt bosses 32 do not contact the front cover 5.

[0031] The first bolt 31a fixes the upper part of one end side (one end portion 6a) in the width direction of the internal combustion engine of the internal combustion engine side mount bracket 6 to the cylinder head 2 outside the front cover 5. The first bolt 31a passes through the first bolt boss portion 32a of the internal combustion engine side mount bracket 6. The first bolt boss portion 32a is formed at one end portion 6a located on one end side of the internal combustion engine side mount bracket 6 in the width direction of the internal combustion engine body 8.

[0032] The second bolt 31b passes through the front cover 5 and fixes the upper part of the substantially central portion in the width direction of the internal combustion engine of the internal combustion engine side mount bracket 6 to the cylinder head 2. The second bolt 31b passes through the second bolt boss portion 32b of the internal combustion engine side mount bracket 6. The second bolt boss portion 32b is formed at the central portion of the internal combustion engine side mount bracket 6 in the width direction of the internal combustion engine body 8.

[0033] The second bolt boss portion 32b passes through the front cover 5. The tip portion on the back side of the front cover 5 of the second bolt boss portion 32b is pressed against the cylinder head 2.

[0034] The third bolt 31c fixes the upper part of the other end side (the other end portion 6b) in the width direction of the internal combustion engine of the internal combustion engine side mount bracket 6 to the cylinder head 2 outside the front cover 5. The third bolt 31c passes through the third bolt boss portion 32c of the internal combustion engine side mount bracket 6. The third bolt boss portion 32c is formed at the other end portion 6b located on the other end side of the internal combustion engine side mount bracket 6 in the width direction of the internal combustion engine body 8.

[0035] The fourth bolt 31d fixes the lower part of one end side (one end portion 6a) in the engine width direction of the engine side mount bracket 6 to the cylinder block 3 outside the front cover 5. The fourth bolt 31d passes through the fourth bolt boss portion 32d of the engine side mount bracket 6. The fourth bolt boss portion 32d is formed at one end portion 6a located on one end side of the engine side mount bracket 6 in the width direction of the engine body 8.

[0036] The fifth bolt 31e passes through the front cover 5 and fixes the lower part of substantially the center in the engine width direction of the engine side mount bracket 6 to the cylinder block 3. The fifth bolt 31e passes through the fifth bolt boss portion 32e of the engine side mount bracket 6. The fifth bolt boss portion 32e is formed at the central portion of the engine side mount bracket 6 in the width direction of the engine body 8.

[0037] The fifth bolt boss portion 32e passes through the front cover 5. The tip portion on the back side of the front cover 5 of the fifth bolt boss portion 32e is pressed against the cylinder block 3.

[0038] The sixth bolt 31f fixes the lower part of the other end side (the other end portion 6b) in the engine width direction of the engine side mount bracket 6 to the cylinder block 3 outside the front cover 5. The sixth bolt 31f passes through the sixth bolt boss portion 32f of the engine side mount bracket 6. The sixth bolt boss portion 32f is formed at the other end portion 6b located on the other end side of the engine side mount bracket 6 in the width direction of the engine body 8.

[0039] The engine side mount bracket 6 has a plurality (three) of mount portions 33.

[0040] The mounting portion 33 is for attaching the internal combustion engine 1 to the vehicle body, and its upper end surface 34 is fixed to the vehicle body side mounting bracket 7 with bolts (not shown). The mounting portion 33 is constituted by a bulging portion having a semi-cylindrical cross-section that protrudes forward of the end surface 8a on one end side of the internal combustion engine main body 8. That is, the back side of the mounting portion 33 is hollowed out. The mounting portion 33 is formed to extend along the vertical direction along the cylinder axis L1 of the internal combustion engine 1. That is, the mounting portion 33 is elongated in the vertical direction, and its upper end surface 34 is fixed to the vehicle body side mounting bracket 7.

[0041] The mounting portion 33 provided on the internal combustion engine side mounting bracket 6 includes a first mounting portion 33a located at one end side in the engine width direction of the internal combustion engine side mounting bracket 6, a second mounting portion 33b located at the other end side in the engine width direction of the internal combustion engine side mounting bracket 6, and a third mounting portion 33c located at the center in the engine width direction of the internal combustion engine side mounting bracket 6.

[0042] For the first mounting portion 33a, its upper end surface 34a is fixed to the vehicle body side mounting bracket 7. For the second mounting portion 33b, its upper end surface 34b is fixed to the vehicle body side mounting bracket 7. For the third mounting portion 33c, its upper end surface 34c is fixed to the vehicle body side mounting bracket 7.

[0043] As shown in FIGS. 3 and 4, the internal combustion engine side mounting bracket 6 has a plurality of ribs 35.

[0044] The ribs 35 are for increasing the rigidity of the internal combustion engine side mounting bracket 6, and connect the fixing points of the internal combustion engine side mounting bracket 6 to the internal combustion engine 1 to each other, or connect the mounting portion 33 and the fixing point of the internal combustion engine side mounting bracket 6 to the internal combustion engine 1. In other words, the ribs 35 connect the bolt boss portions 32 to each other, or connect the mounting portion 33 and the bolt boss portion 32. The ribs 35 are ridges formed to protrude from the back surface of the internal combustion engine side mounting bracket 6 toward the one end surface side of the internal combustion engine 1, and are formed solid, for example.

[0045] In this embodiment, ten ribs 35, i.e., first ribs 35a to tenth ribs 35j, are provided on the internal combustion engine side mount bracket 6.

[0046] The first rib 35a corresponds to the upper rib, linearly extends along the width direction of the internal combustion engine, and connects the first bolt boss portion 32a and the second bolt boss portion 32b. Further, the first rib 35a is connected to the upper end of the first mount portion 33a.

[0047] The second rib 35b corresponds to the upper rib, linearly extends along the width direction of the internal combustion engine, and connects the second bolt boss portion 32b and the third bolt boss portion 32c. Further, the second rib 35b is connected to the upper ends of the second mount portion 33b and the third mount portion 33c.

[0048] The third rib 35c corresponds to the lower rib, linearly extends obliquely along the width direction of the internal combustion engine, and connects the fourth bolt boss portion 32d and the fifth bolt boss portion 32e. Further, the third rib 35c is connected to the lower ends of the first mount portion 33a and the third mount portion 33c.

[0049] The fourth rib 35d corresponds to the lower rib, linearly extends obliquely along the width direction of the internal combustion engine, and connects the fifth bolt boss portion 32e and the sixth bolt boss portion 32f. Further, the fourth rib 35d is connected to the lower ends of the second mount portion 33b and the third mount portion 33c.

[0050] The fifth rib 35e linearly extends along the vertical direction along the cylinder axis L1 of the internal combustion engine 1, and connects the first bolt boss portion 32a and the fourth bolt boss portion 32d. Further, the fifth rib 35e is connected to the lower end of the first mount portion 33a.

[0051] The sixth rib 35f extends linearly obliquely along the vertical direction along the cylinder axis L1 of the internal combustion engine 1, and connects the second bolt boss portion 32b and the fifth bolt boss portion 32e. Further, the sixth rib 35f is connected to the upper end of the first mount portion 33a and the lower end of the third mount portion 33c.

[0052] The seventh rib 35g extends along the vertical direction along the cylinder axis L1 of the internal combustion engine 1, and connects the third bolt boss portion 32c and the sixth bolt boss portion 32f. Further, the seventh rib 35g is formed to curve in an arc shape toward the outside of the internal combustion engine 1 rather than the second mount portion 33b in the width direction of the internal combustion engine, and the upper end is connected to the upper end of the second mount portion 33b, and the lower end is connected to the lower end of the second mount portion 33b.

[0053] The eighth rib 35h extends linearly obliquely along the vertical direction along the cylinder axis L1 of the internal combustion engine 1, and connects the second bolt boss portion 32b and the fourth bolt boss portion 32d. Further, the eighth rib 35h is connected to the upper end and the lower end of the first mount portion 33a.

[0054] The ninth rib 35i extends linearly obliquely along the vertical direction along the cylinder axis L1 of the internal combustion engine 1, and connects the second bolt boss portion 32b and the sixth bolt boss portion 32f. Further, the ninth rib 35i is connected to the upper end of the first mount portion 33a and the lower end of the second mount portion 33b.

[0055] The tenth rib 35j extends linearly obliquely along the vertical direction along the cylinder axis L1 of the internal combustion engine 1, and connects the upper end of the second mount portion 33b and the fifth bolt boss portion 32e. Further, the tenth rib 35j is formed so as to cross the third mount portion 33c.

[0056] The internal combustion engine 1 of the above-described embodiment has one end portion 6a and the other end portion 6b, which are both side portions in the width direction (the direction along the Y-axis) of the internal combustion engine main body 8 of the internal combustion engine side mounting bracket 6, respectively fixed to both the cylinder head 2 and the cylinder block 3 by bolts 31, which are fastening elements. One end portion 6a is the end portion of the internal combustion engine side mounting bracket 6 located on the exhaust port side of the internal combustion engine 1. The other end portion 6b is the end portion of the internal combustion engine side mounting bracket 6 located on the intake port side of the internal combustion engine 1.

[0057] That is, in the internal combustion engine side mounting bracket 6, the upper part of one end portion 6a (one end side), which is on the left side in FIG. 4 in the left-right direction along the width direction (the direction along the Y-axis) of the internal combustion engine main body 8, is fixed to the cylinder head 2 by the first bolt 31a. Further, in the internal combustion engine side mounting bracket 6, the lower part of one end portion 6a (one end side), which is on the left side in FIG. 4 in the left-right direction along the width direction (the direction along the Y-axis) of the internal combustion engine main body 8, is fixed to the cylinder block 3 by the fourth bolt 31d.

[0058] In the internal combustion engine side mounting bracket 6, the upper part of the other end portion 6b (the other end side), which is on the right side in FIG. 4 in the left-right direction along the width direction (the direction along the Y-axis) of the internal combustion engine main body 8, is fixed to the cylinder head 2 by the third bolt 31c. Further, in the internal combustion engine side mounting bracket 6, the lower part of the other end portion 6b (the other end side), which is on the right side in FIG. 4 in the left-right direction along the width direction (the direction along the Y-axis) of the internal combustion engine main body 8, is fixed to the cylinder block 3 by the sixth bolt 31f.

[0059] That is, the internal combustion engine side mounting bracket 6 is attached to the internal combustion engine main body 8 across the cylinder head 2 and the cylinder block 3 outside the outer peripheral edge of the front cover 5.

[0060] Further, recesses 20 are formed in the one end portion 6a and the other end portion 6b of the internal combustion engine side mounting bracket 6, respectively. That is, in the internal combustion engine side mounting bracket 6, a first recess 20a is formed in the fifth rib 35e, and a second recess 20b is formed in the seventh rib 35g.

[0061] In other words, the recess 20 is formed on the mounting surface 21 of the engine-side mounting bracket 6 that is attached to the engine body 8. The mounting surface 21 of the engine-side mounting bracket 6 faces the end face 8a on one end side in the cylinder row direction of the engine body 8, and is abutted against and fixed to the end face 8a. Therefore, the recess 20 is recessed so as to be separated from the end face 8a of the engine body 8 when the engine-side mounting bracket 6 is attached to the engine body 8.

[0062] And, as shown in FIGS. 2, 5, and 6, in the internal combustion engine 1, due to such a recess 20, a visible gap 22 is formed between the engine-side mounting bracket 6 and the engine body 8 at the portion where the three members of the cylinder head 2, the cylinder block 3, and the front cover 5 are joined together. FIG. 5 is a perspective view showing a main part of the internal combustion engine 1. FIG. 6 is a side view of one end side of the internal combustion engine 1 in the cylinder row direction as viewed from the exhaust port side. That is, FIG. 6 is a view of the internal combustion engine 1 or the engine body 8 from a direction orthogonal to a plane including the central axis of the crankshaft 19 and parallel to the cylinder axis L1 of the cylinder block 3.

[0063] A gap 22a is formed between the first recess 20a and the engine body 8 on the exhaust port side of the internal combustion engine 1. A gap 22b is formed between the second recess 20b and the engine body 8 on the intake port side of the internal combustion engine 1.

[0064] As shown in FIG. 6, the outer surface of the recess 20 has an upper surface 23 located on the upper side in the vertical direction along the cylinder axis L1 in a side view of the engine body 8, a lower surface 24 located on the lower side in the vertical direction along the cylinder axis L1, and a central surface 25 located between the upper surface 23 and the lower surface 24. That is, the first recess 20a has an upper surface 23a, a lower surface 24a, and a central surface 25a, and the second recess 20b has an upper surface 23b, a lower surface 24b, and a central surface 25b. Note that the first recess 20a has a similar shape to the second recess 20b.

[0065] The upper surface 23 abuts against the end face 8a at one end side of the engine body 8 at its upper end in a state where the engine side mount bracket 6 is attached to the engine body 8, and the upper end is continuous with the end face 8a.

[0066] The lower surface 24 abuts against the end face 8a at one end side of the engine body 8 at its lower end in a state where the engine side mount bracket 6 is attached to the engine body 8, and the upper end is continuous with the end face 8a.

[0067] The central surface 25 faces the end face 8a at one end side of the engine body 8 in a state where the engine side mount bracket 6 is attached to the engine body 8. The central surface 25 is in the vertical direction along the cylinder axis L1, and the upper end portion on the upper side is continuous with the upper surface 23, and the lower end portion on the lower side is continuous with the lower surface 24.

[0068] Further, the recess 20 is formed such that the upper surface 23 and the lower surface 24 are not parallel to each other. In the present embodiment, the entire outer surface of the recess 20 is formed into a C-shaped curved surface so that the upper surface 23 and the lower surface 24 are not parallel to each other.

[0069] Further, as shown in FIGS. 2, 5, and 6, a heat shield plate 26 is attached to one end side of the engine body 8 in the cylinder row direction of the internal combustion engine 1. The heat shield plate 26 is located on the exhaust port side of the engine body 8.

[0070] The heat shield plate 26 is located on the side of the gap 22a and is attached to the engine body 8 so as to extend in the vertical direction along the cylinder axis L1 and straddle the cylinder head 2 and the cylinder block 3. The heat shield plate 26 is attached to the engine body 8 so as to cover a part of the mating surface between the end face 8a at one end side in the cylinder row direction of the engine body 8 and the outer peripheral edge of the front cover 5 in the cylinder row direction of the engine body 8 when viewed from the side of the engine body 8. The above mating surface can also be regarded as the end face 8a.

[0071] The heat shield 26 is formed to have a predetermined width along the cylinder row direction of the internal combustion engine body 8 so as to be able to cover the mating surface between the end surface 8a on one end side in the cylinder row direction of the internal combustion engine body 8 and the outer peripheral edge of the front cover 5.

[0072] Further, as shown in FIGS. 2, 5, 6, and 7, the heat shield 26 is a plate-like member made of an elongated metal material along the cylinder axis L1. For example, the upper end portion in the vertical direction along the cylinder axis L1 is fixed to the cylinder head 2 with bolts 27a, and the lower end portion in the vertical direction along the cylinder axis L1 is fixed to the cylinder block 3 with bolts 27b. FIG. 7 is a perspective view of the heat shield 26.

[0073] Further, on the heat shield 26, at a position having a gap 22a in the vertical direction along the cylinder axis L1, a bulging portion 28 that protrudes in a direction away from the gap 22a is formed.

[0074] That is, the bulging portion 28 is formed such that in a side view of the internal combustion engine body 8 when the heat shield 26 is attached to the internal combustion engine body 8, the height position in the vertical direction along the cylinder axis L1 overlaps with the gap 22a.

[0075] In the internal combustion engine 1 of the above-described embodiment, since the visible gap 22 is provided on the intake port side and the exhaust port side of the internal combustion engine 1 at the portion where the three members of the cylinder head 2, the cylinder block 3, and the front cover 5 are joined together, the state of the portion where the three members of the cylinder head 2, the cylinder block 3, and the front cover 5 are joined together can be easily visually confirmed.

[0076] The internal combustion engine 1 is firmly received (supported) by the vehicle body by a metal internal combustion engine side mount bracket 6 attached so as to cover the outer peripheral edge of the front cover 5.

[0077] The recess 20 of the internal combustion engine side mount bracket 6 is formed in a portion that does not require rigidity when the internal combustion engine side mount bracket 6 vibrates. In other words, the recess 20 is formed at a position away from the portion where the mount portion 33 of the internal combustion engine side mount bracket 6 is provided.

[0078] The internal combustion engine 1 can effectively utilize a portion that does not require rigidity when the internal combustion engine side mount bracket 6 vibrates, so that the state of the portion where the three members of the cylinder head 2, the cylinder block 3, and the front cover 5 are joined can be visually observed.

[0079] The recess 20 of the internal combustion engine side mount bracket 6 is formed such that the upper surface 23 and the lower surface 24 are not parallel to each other.

[0080] As shown in Fig. 8(a), in the recess 20 of the comparative example, the upper surface 23 and the lower surface 24 are parallel, so standing waves are generated and the sound is amplified. On the other hand, as shown in Fig. 8(b), the recess 20 of the above-described embodiment is formed such that the upper surface 23 and the lower surface 24 are not parallel to each other. Fig. 8 is a functional explanatory diagram of the recess 20 formed in the internal combustion engine side mount bracket 6, (a) schematically shows the recess 20 of the comparative example, and (b) schematically shows the recess 20 of the above-described embodiment.

[0081] Therefore, the internal combustion engine can suppress the generation of standing waves that lead to sound amplification and suppress the radiated sound.

[0082] As shown in Fig. 2, the front cover 5 is formed such that a part of the outer peripheral edge is located within the first recess 20a. In other words, the front cover 5 is formed such that a part of the outer peripheral edge overlaps with the first recess 20a when viewed in the crankshaft axial direction.

[0083] As a result, the engine-side mounting bracket 6 can suppress the length dimension along the width direction of the engine body 8 at the portion where the first recess 20a (gap 22a) is provided. That is, the engine-side mounting bracket 6 does not protrude outside the outer peripheral edge of the front cover 5 at the portion where the first recess 20a (gap 22a) is provided. Therefore, the engine 1 can generally suppress the length dimension along the width direction of the engine body 8 and can be downsized.

[0084] The heat shield plate 26 blocks the heat traveling from the other end side to the one end side in the cylinder row direction of the engine body 8 and protects the sealing material that seals between the front cover 5 and between the front cover 5 and the engine body 8 from the heat of the exhaust system components.

[0085] The engine 1 can easily visually observe the state of the portion where the three members of the cylinder head 2, the cylinder block 3, and the front cover 5 are joined together by the bulging portion 28 of the heat shield plate 26 while maintaining the heat shielding function of the resin front cover 5 by the heat shield plate 26.

[0086] In addition, the heat shield plate 26 improves the surface rigidity due to the bulging portion 28, and also improves (enhances) the radiation characteristics such as sound and vibration.

[0087] As described above, the specific embodiments of the present invention have been described. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit thereof.

[0088] For example, if the upper surface 23 and the lower surface 24 of the recess 20 are not parallel to each other, the upper surface 23 and the lower surface 24 may be formed as planes. Further, the recess 20 may be formed with a flat central surface 25 instead of a curved surface.

Explanation of Reference Numerals

[0089] 1... Engine 2... Cylinder head 3... Cylinder block 5... Front cover 6... Engine-side mounting bracket 6a…one end 6b…the other end 8…internal combustion engine body 8a…end face 20…recess 21…mounting surface 22…gap 23…upper surface 24…lower surface 25…central plane 26…heat shield 28…bulge

Claims

1. a front cover that covers an end face on one end side in a cylinder row direction of an internal combustion engine body having a cylinder head and a cylinder block and has an outer circumferential edge that is attached to the internal combustion engine body; and a mounting member that is attached to the internal combustion engine body outside the outer circumferential edge of the front cover and straddles the cylinder head and the cylinder block, an internal combustion engine, characterized in that a gap is formed between the mounting member and the internal combustion engine body, through which the portion where the three members, the cylinder head, the cylinder block, and the front cover, are joined together can be visually observed.

2. 2. The internal combustion engine according to claim 1, wherein the front cover is made of resin, and the mounting member is a metal mount bracket for mounting the internal combustion engine body to a vehicle.

3. the gap is formed by a recess provided in a mounting surface of the mount bracket that is attached to the internal combustion engine body, the mounting surface faces an end surface of one end of the internal combustion engine body in a cylinder row direction, 3. The internal combustion engine according to claim 2, wherein the recess is recessed so as to be spaced apart from an end face on one end side of the internal combustion engine body in a cylinder row direction.

4. 4. The internal combustion engine according to claim 3, wherein the recess has an upper side located on the upper side in the vertical direction along the cylinder axis and abutting against an end face of one end of the internal combustion engine body in the cylinder row direction, a lower side located opposite the upper side and on the lower side in the vertical direction along the cylinder axis and abutting against an end face of one end of the internal combustion engine body in the cylinder row direction, and a central surface located between the upper side and the lower side and facing the end face of one end of the internal combustion engine body in the cylinder row direction, and the upper side and the lower side are formed so that they are not parallel to each other.

5. 5. The internal combustion engine according to claim 4, wherein the upper surface, the lower surface and the central surface are each formed to be a curved surface.

6. 3. The internal combustion engine according to claim 2, wherein the front cover is formed such that a part of an outer circumferential edge is positioned within the recess when viewed in the axial direction of the crankshaft.

7. a heat shield plate that is located to the side of the gap, extends in a vertical direction along a cylinder axis, straddles the cylinder head and the cylinder block, and is attached to the internal combustion engine body so as to cover a mating surface between an end face on one end side of the internal combustion engine body in the cylinder row direction and an outer circumferential edge of the front cover in the cylinder row direction of the internal combustion engine body, 3. The internal combustion engine according to claim 2, wherein the heat shield has a bulge formed at a position where the gap is present in the vertical direction along the cylinder axis, the bulge extending in a direction away from the gap.

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