Internal combustion engine

Abstract

To improve sound / vibration performance of an internal combustion engine.SOLUTION: A balancer opposing part 32 is a portion overlapping a rotating member in a balancer shaft axial direction view and is formed to have a stepwise shape including a first wall 42 located in parallel with a flat surface orthogonal to a balancer shaft, a second wall 43 located in parallel with the flat surface orthogonal to the balancer shaft and separating from an internal combustion engine body compared to the first wall 42 and a third wall 44 that connects the first wall 42 and the second wall 43. A wire harness 51 is supported by a boss part 54 formed on the second wall 43 of the balancer opposing part 32 via a bracket 52.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] For example, Patent Document 1 discloses a timing chain cover that is joined to an engine body consisting of a cylinder block, a cylinder head, a crankcase, etc., at one axial end of the crankshaft. The timing chain cover in Patent Document 1 includes a chain cover body made of an aluminum alloy and a vibration-damping resin layer formed on the surface of the chain cover body that comes into contact with the engine body, and the vibration-damping resin layer acts to suppress the transmission of vibration between the engine body and the chain cover body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-139487 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in Patent Document 1, the timing chain cover is made of metal, and no consideration is given to the noise and vibration performance that is unique to resin covers. In other words, there is room for further improvement in terms of improving noise and vibration performance when attaching a resin cover to the engine body at one end of the crankshaft in the axial direction. [Means for solving the problem]

[0005] The internal combustion engine of the present invention comprises a rotating member attached to one end of a balancer shaft arranged parallel to the crankshaft, a resin front cover covering an end face at one end of the internal combustion engine body in the cylinder row direction, and a wire harness arranged along the outer surface of the front cover, and is characterized in that the front cover supports the wire harness on the forward side of the rotating member, which is at one end of the internal combustion engine body in the cylinder row direction. [Effects of the Invention]

[0006] The internal combustion engine of the present invention can improve the noise and vibration performance of the front cover by utilizing the mass of the wire harness. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is an explanatory diagram that schematically shows the general configuration of an internal combustion engine according to the present invention; [Figure 2] FIG. 2 is a front view of a front cover of the internal combustion engine according to the present invention. [Figure 3] FIG. 2 is a rear view of the front cover of the internal combustion engine according to the present invention. [Figure 4] FIG. 3 is a cross-sectional view of the front cover taken along line AA in FIG. 2. [Figure 5] 1 is an enlarged view of a main portion of an internal combustion engine according to the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0008] An embodiment of the present invention will be described in detail below with reference to the drawings. In each drawing, the X-axis indicates an axis along the longitudinal direction of the internal combustion engine 1 (an axis parallel to the central axis of the crankshaft 11 of the internal combustion engine 1), the Y-axis indicates an axis along the left-right direction (width direction of the internal combustion engine) of the internal combustion engine 1, and the Z-axis indicates an axis along the vertical direction of the internal combustion engine 1 (an axis parallel to the cylinder axis L of the internal combustion engine 1). In other words, the X-axis is an axis along the direction in which the cylinders of the internal combustion engine 1 or the internal combustion engine main body 8 (described later) are aligned. The Y-axis is an axis along the width direction of the internal combustion engine main body 8. The internal combustion engine 1 is mounted on, for example, a vehicle.

[0009] 1 is an explanatory diagram showing a schematic configuration of an internal combustion engine 1 according to the present invention. The internal combustion engine 1 is, for example, an in-line multi-cylinder internal combustion engine, and has a cylinder head 2, a cylinder block 3 attached to the bottom of the cylinder head 2, a cam bracket 4 attached to the top of the cylinder head 2, an upper oil pan 5 attached to the bottom of the cylinder block 3, a lower oil pan 6 attached to the bottom of the upper oil pan 5, and a front cover 7 that covers the front of an internal combustion engine body 8. The cylinder head 2, cylinder block 3, cam bracket 4, and upper oil pan 5 together constitute the internal combustion engine body 8.

[0010] The cylinder head 2 is a casting made of a metal material such as an aluminum alloy, and is formed with an intake port (not shown) that supplies intake air to a combustion chamber (not shown), and an exhaust port (not shown) that discharges exhaust gas from the combustion chamber (not shown).

[0011] The cylinder block 3 is a casting made of a metal material such as an aluminum alloy, and has cylinders (not shown) formed therein in the number corresponding to the number of cylinders.

[0012] The cam bracket 4 is made of a metal material such as an aluminum alloy, and supports a camshaft (not shown) together with the cylinder head 2 so that the camshaft can rotate.

[0013] The oil pan upper 5 is made of a metal material such as an aluminum alloy, and together with the cylinder block 3 constitutes a crankcase (not shown) that houses a crankshaft 11 (see FIGS. 2 and 3).

[0014] The oil pan lower 6 is made of a synthetic resin material such as polyamide, and stores oil for lubrication.

[0015] The front cover 7 is made of a synthetic resin material such as polyamide, and is attached liquid-tight 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 7 is attached to the front surfaces of the cylinder block 3, the cylinder head 2, the cam bracket 4, and the oil pan upper 5 with bolts (not shown). In other words, the front cover 7 is attached to the internal combustion engine body 8 so as to cover the end faces of one end of the cylinder block 3 and one end of the cylinder head 2 in the crankshaft axial direction (X-axis direction), i.e., one end of the internal combustion engine body 8 in the cylinder row direction. The front cover 7 has a shallow dish shape, and forms a space between the front surface of the internal combustion engine body 8 and the front surface of the internal combustion engine body 8 that communicates with the oil pans 5 and 6.

[0016] 2 and 3, the front cover 7 has a boss through-hole 12, a crankshaft through-hole 13, a first bolt through-hole 14, and a second bolt through-hole 15. Fig. 2 is a front view of the front cover 7. Fig. 3 is a rear view of the front cover 7.

[0017] The boss through-holes 12 are formed at two locations in the central portion of the front cover 7 in the width direction of the internal combustion engine body 8, and are passed by bolt bosses (not shown) of a mount bracket (not shown) for attaching the internal combustion engine body 8 to a vehicle. The outer peripheral edge of the boss through-holes 12 forms an annular (cylindrical) through-hole peripheral portion 16. The through-hole peripheral portion 16 is pressed against and comes into contact with an end face on one end side of the internal combustion engine body 8 in the cylinder row direction on the back side of the front cover 7, and supports the central portion of the front cover 7 on the internal combustion engine body 8.

[0018] The gap between the through-hole peripheral portion 16 and the internal combustion engine body 8 is liquid-tight sealed by the first seal material 17. In addition, the gap between the periphery of the second bolt through-hole 15 and the internal combustion engine body 8 is liquid-tight sealed by the first seal material 17. In other words, the periphery of the boss portion through-hole 12 and the periphery of the second bolt through-hole 15 are sealed by the first seal material 17.

[0019] The first sealing material 17 is a single, elongated, continuous member extending in the vertical direction (along the Z-axis) of the front cover 7, sealing between the through-hole peripheral portion 16 and the front cover boss portion 21 (described later) and the internal combustion engine body 8.

[0020] The crankshaft through-hole 13, through which the crankshaft 11 passes, is formed below the boss through-hole 12. The periphery of the crankshaft through-hole 13 is sealed liquid-tight.

[0021] The first bolt through-holes 14 are formed in plurality (a large number) on the outer periphery of the front cover 7, and are adapted to receive bolts (not shown) that secure the outer periphery of the front cover 7 to the internal combustion engine body 8. The outer periphery of the front cover 7 is liquid-tightly sealed all around by an annular outer periphery seal material 18. The outer periphery seal material 18 is located more inward than the first bolt through-holes 14.

[0022] The second bolt through-holes 15 are formed in a plurality (for example, four) of the front cover 7 so that bolts (not shown) can pass through them to secure the portion of the front cover 7 other than the outer peripheral edge to the internal combustion engine body 8. The second bolt through-holes 15 are formed in a front cover boss portion 21. The front cover boss portion 21 is fixed on the back side of the front cover 7 with its tip surface pressed against an end surface on one end side of the internal combustion engine body 8 in the cylinder row direction. A first seal material 17 provides a liquid-tight seal between the front cover boss portion 21 and the internal combustion engine body 8.

[0023] 2 to 5, the front cover 7 is further formed with a crank pulley facing portion 31 and a balancer facing portion 32. Fig. 4 is a cross-sectional view of the front cover 7 taken along line AA in Fig. 2. Fig. 5 is an enlarged view of a main portion of the internal combustion engine 1.

[0024] The crank pulley facing portion 31 is a flat plate-shaped portion around the crankshaft through-hole 13, sandwiched between a crank sprocket 33 and a crank pulley 34 fixed to the front end of the crankshaft 11. An accessory drive belt (not shown) is wound around the crank pulley 34. The crank pulley 34 is located outside the front cover 7, and drives accessories (not shown), such as a water pump, via the accessory drive belt.

[0025] The balancer facing portion 32 is a stepped portion facing a disk-shaped rotating member 37 attached to one end of the balancer shaft 36. The balancer shaft 36 is disposed parallel to the crankshaft 11 and rotates in the opposite direction to the crankshaft 11. The rotating member 37 is disposed at one end of the internal combustion engine body 8 in the cylinder row direction and has a larger diameter than the balancer shaft 36. The rotating member 37 is covered by the balancer facing portion 32 of the front cover 7. The balancer shaft 36 and the rotating member 37 are members that contribute to suppressing vibrations of the internal combustion engine 1.

[0026] The balancer facing portion 32 is a portion that overlaps with the rotary member 37 when viewed in the axial direction of the balancer shaft 36 (crankshaft 11).

[0027] The balancer opposing portion 32 has a recess 41 recessed toward the internal combustion engine body 8. In other words, the balancer opposing portion 32 is formed in a stepped shape and has a first wall 42 parallel to a plane perpendicular to the balancer shaft 36 (crankshaft 11), a second wall 43 parallel to the plane perpendicular to the balancer shaft 36 (crankshaft 11) and farther from the internal combustion engine body 8 than the first wall 42, and a third wall 44 connecting the first wall 42 and the second wall 43. The recess 41 of the balancer opposing portion 32 is formed by the third wall 44 and the first wall 42 which is closer to the internal combustion engine body 8 than the second wall 43.

[0028] In other words, the balancer opposing portion 32 is divided into two parts: a recessed portion 41 which is a recessed portion located on the internal combustion engine main body 8 side in the axial direction of the balancer shaft 36 (crankshaft 11), and a convex portion 45 which is a convex portion which is farther away from the internal combustion engine main body 8 than the recessed portion 41 in the axial direction of the balancer shaft 36 (crankshaft 11).

[0029] 3 and 4, a plurality of ribs 46 extending (protruding) along the axial direction of the balancer shaft 36 (crankshaft 11) are formed on the balancer facing portion 32. The ribs 46 are formed on the back surface side of the balancer facing portion 32 that faces the internal combustion engine body 8.

[0030] Furthermore, the internal combustion engine 1 has a wire harness 51 arranged along the outer surface of the front cover 7, as shown in FIG.

[0031] The wire harness 51 electrically connects, for example, between a control device (not shown) of the internal combustion engine 1 and various controlled devices of the internal combustion engine 1 (for example, a throttle valve, a fuel injection valve, etc.), or between the control device of the internal combustion engine 1 and various sensors attached to the internal combustion engine 1. The wire harness 51 is supported by the balancer opposing part 32 via a bracket 52. When viewed in the axial direction of the balancer shaft 36 (crankshaft 11), the wire harness 51 is located on the first wall 42 of the balancer opposing part 32 and arranged along the third wall 44.

[0032] The bracket 52 has, for example, a flat rectangular plate shape, one end of which is fixed by a screw 53 to a boss portion 54 formed on the second wall 43 of the balancer opposing portion 32, and the wire harness 51 is attached to the other end. The bracket 52 is disposed on the balancer opposing portion 32 so as to straddle the third wall 44 when viewed in the axial direction of the balancer shaft 36 (crankshaft 11). The bracket 52 is in contact with the second wall 43 of the balancer opposing portion 32, and is therefore more likely to reduce, by its own weight, surface vibrations of the front cover 7 caused by vibrations of the internal combustion engine 1. The bracket 52 has, for example, a tunnel-shaped harness attachment portion at the other end through which the wire harness 51 can pass.

[0033] 3 to 5, the boss portion 54 is formed so as to be continuous with the rib 46. In other words, a plurality of ribs 46 are connected to the boss portion 54. In addition, a tip surface 54a of the boss portion 54 protrudes outward beyond the outer surface of the second wall 43.

[0034] In the internal combustion engine 1 of the embodiment described above, the rotating member 37 is disposed inside the front cover 7 in front of the balancer shaft 36. As a result, the area of the portion of the front cover 7 located forward of the rotating member 37 (the balancer facing portion 32) increases compared to when the rotating member 37 is not present, making the membrane more susceptible to vibration. However, although it would be desirable to increase the thickness of the front cover 7 or the height of the ribs 46, it is necessary to reduce the thickness to avoid an increase in weight, and to reduce the height of the ribs 46 due to the presence of the rotating member 37. As a result, there is a risk that membrane vibration will increase in the portion of the front cover 7 located forward of the rotating member 37, deteriorating the noise and vibration performance of the internal combustion engine 1.

[0035] Therefore, the internal combustion engine 1 supports the wire harness 51 at a portion of the front cover 7 located forward of the rotating member 37, where there is a risk that the sound vibration performance may be deteriorated due to membrane vibration of the front cover 7, thereby adding the mass of the wire harness 51 to this portion.

[0036] As a result, the internal combustion engine 1 can utilize the mass of the wire harness 51 to suppress membrane vibration of the front cover 7 and improve the sound vibration performance of the balancer opposing portion 32, which is a part where sound vibration performance may be deteriorated.

[0037] The provision of the ribs 46 in the front cover 7 of the internal combustion engine 1 improves the rigidity of the balancer facing portion 32. As a result, the internal combustion engine 1 can obtain an effect of improving the sound and vibration performance by improving the rigidity of the balancer facing portion 32, which is a portion of the front cover 7 that may deteriorate the sound and vibration performance.

[0038] In the internal combustion engine 1, by providing the ribs 46 on the back surface side of the front cover 7, the front surface side of the front cover 7 can be formed into a smooth surface without irregularities.

[0039] Furthermore, by recessing a portion of the balancer facing portion 32 of the front cover 7 toward the internal combustion engine body 8, the wire harness 51 can be routed within the engine compartment without interfering with surrounding components, and the structural strength of the balancer facing portion 32 can be improved.

[0040] Furthermore, the front cover 7 is formed so that the boss portion 54 of the balancer facing portion 32 is continuous with the rib 46 .

[0041] As a result, in the internal combustion engine 1, the strength of the front cover 7 that supports the mass of the wire harness 51 is improved, and the mass of the wire harness 51 can be supported over a wide range by the ribs 46.

[0042] Although specific embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the invention. [Explanation of symbols]

[0043] 1...Internal combustion engine 7...Front cover 8...Internal combustion engine body 16...Periphery of through hole 31...Crank pulley facing part 32...Facing part of balancer 41...recess 42…First wall 43…Second wall 44…Third wall 45...Convex part 46...Rib 51...Wire harness 52...Bracket 53...Screw 54...Boss section

Claims

1. a balancer shaft arranged parallel to the crankshaft; a disk-shaped rotating member attached to one end of the balancer shaft and disposed on one end side of the internal combustion engine body in the cylinder row direction; a resin front cover that covers one end face of the internal combustion engine body in the cylinder row direction; a wire harness arranged along the outer surface of the front cover, The internal combustion engine is characterized in that the front cover supports the wire harness on the front side of the rotating member, which is one end side of the internal combustion engine body in the cylinder row direction.

2. the front cover has a balancer facing portion that overlaps with the rotating member when viewed in the balancer shaft axial direction, 2. The internal combustion engine according to claim 1, wherein the wire harness is supported by the portion facing the balancer.

3. 3. The internal combustion engine according to claim 2, wherein the balancer facing portion is formed with a rib extending along the axial direction of the balancer shaft.

4. the rib is formed on a back surface side of the balancer facing portion that faces the internal combustion engine body, 4. The internal combustion engine according to claim 3, wherein the balancer facing portion has a recessed portion recessed toward the internal combustion engine body.

5. The wire harness is supported by the balancer facing portion via a bracket, The bracket is screwed to a boss formed on the balancer facing portion, 4. The internal combustion engine according to claim 3, wherein the boss portion is formed so as to be continuous with the rib.

6. the balancer facing portion is formed in a stepped shape and includes a first wall parallel to a plane perpendicular to the balancer shaft, a second wall parallel to the plane perpendicular to the balancer shaft and spaced apart from the internal combustion engine body as compared to the first wall, and a third wall connecting the first wall and the second wall, the wire harness is located on the first wall as viewed in the balancer shaft axial direction and is arranged along the third wall, 6. The internal combustion engine according to claim 5, wherein the bracket is supported by the second wall.

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