Internal combustion engine

Abstract

To further improve the function of an internal combustion engine.SOLUTION: An internal combustion engine includes a cylinder block 1 in which a flange 4 for attaching another component to an outer peripheral edge on one end side in a cylinder row direction is formed so as to protrude to an outer peripheral side, and a lid member 6 attached to a side wall 2 of the cylinder block 1 and forming an oil separator 3 between the side wall 2 and itself. The lid member 6 has a first attachment surface 8 attached to the side wall 2 of the cylinder block 1 and a second attachment surface 9 attached to the flange 4 of the cylinder block 1. The lid member 6 is formed such that the second attachment surface 9 is orthogonal to the first attachment surface 8.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an internal combustion engine in which an oil separator is formed on a side surface of a cylinder block. [Background technology]

[0002] For example, Patent Document 1 discloses an oil separator provided on the outer side of a cylinder block. In the oil separator of Patent Document 1, the oil separator chamber is composed of a side wall of the cylinder block, a frame-shaped outer peripheral wall protruding laterally from the side wall, and a flat cover plate attached to the tip of the outer peripheral wall. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Publication number 6-27778 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the oil separator in Patent Document 1 is merely set on the side wall of the cylinder block. That is, when setting the oil separator on the side wall of the cylinder block, there is room for further improvement in terms of improving the performance of the internal combustion engine by giving the oil separator a function other than gas-liquid separation of blow-by gas. [Means for solving the problem]

[0005] The internal combustion engine of the present invention includes a cylinder block having a flange formed on the outer periphery at one end in the direction of cylinder alignment so as to protrude outward for mounting other components, and a cover member attached to a side wall of the cylinder block to form an oil separator between the cover member and the side wall. The cover member has a first mounting surface attached to the side wall of the cylinder block and a second mounting surface attached to the flange of the cylinder block, and is formed so that the second mounting surface is perpendicular to the first mounting surface. [Effects of the Invention]

[0006] In the internal combustion engine, the cover member is fastened to two different surfaces of the cylinder block, that is, the side wall and the flange. The cover member 6 can improve the overall rigidity of the internal combustion engine of the present invention. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a perspective view of a cylinder block of an internal combustion engine to which the present invention is applied; [Figure 2] FIG. 4 is a perspective view of the cylinder block with the cover member attached. [Figure 3] FIG. 4 is a perspective view of a cover member attached to the cylinder block. [Figure 4] FIG. 2 is a rear view of the cover member attached to the cylinder block 1. [Figure 5] 4. FIG. 5 is a cross-sectional view taken along line AA in FIG. [Figure 6] FIG. 4 is an explanatory diagram showing the posture when the cover member is attached to the cylinder block. DETAILED DESCRIPTION OF THE INVENTION

[0008] An embodiment of the present invention will be described in detail below with reference to the drawings.

[0009] FIG. 1 is a perspective view of a cylinder block 1 of an internal combustion engine to which the present invention is applied. FIG. 2 is a perspective view of the cylinder block 1 of an internal combustion engine to which the present invention is applied, showing the cylinder block 1 with a cover member 6 attached. FIG. 3 is a perspective view of the cover member 6 attached to the cylinder block 1. FIG. 4 is a rear view of the cover member 6 attached to the cylinder block 1. Note that FIG. 2 shows the state in which the cover member 6 is attached to the cylinder block 1.

[0010] The internal combustion engine is mounted on a vehicle and has a cylinder block 1 made of metal (for example, aluminum alloy).

[0011] As shown in FIG. 1, a cylinder block 1 has an oil separator 3 formed on one side wall 2 thereof.

[0012] As shown in Figures 1 and 2, the cylinder block 1 has a flange 4 for mounting other components that protrudes outward from the outer peripheral edge of the rear end, which is one end in the cylinder row direction. The flange 4 is formed to protrude relative to the side wall 2 on which the oil separator 3 is formed. In other words, the flange 4 is formed to protrude along the radial direction of the crankshaft (not shown) of the internal combustion engine. The flange 4 has a front surface 4a on one side surface in the cylinder row direction, where other components are mounted, and a back surface 4b on the other side surface in the cylinder row direction.

[0013] For example, if the internal combustion engine is used exclusively for generating electricity by driving a generator, the other component attached to the flange 4 will be a reducer located between the engine and the generator. Also, if the internal combustion engine applies the rotation of a crankshaft (not shown) as driving force to the drive wheels of the vehicle, the other component attached to the flange 4 will be a transmission.

[0014] 1 to 3, the oil separator 3 is generally composed of one side wall 2 of the cylinder block 1, a continuous annular protruding wall 5 protruding from the side wall 2, and a metal cover member 6 covering the space inside the protruding wall 5. The oil separator 3 separates oil from the introduced blow-by gas.

[0015] As shown in Figure 1, the protruding wall 5 is continuous in an annular shape, and a cover member 6 is attached to its tip end surface 5a. A plurality of bolt boss portions 7 into which first bolts 21 (see Figure 6 described later) are inserted are formed on the outer periphery of the protruding wall 5. The tip end surfaces 7a of the bolt boss portions 7 are formed to be located on the same plane as the tip end surface 5a of the protruding wall 5. The tip end surface 5a of the protruding wall 5 is formed on a plane that includes the cylinder central axis L1 of the cylinder block 1 and is parallel to a plane that is parallel to the crankshaft central axis L2.

[0016] The cover member 6 is made of, for example, the same metal material as the cylinder block 1. Between the cover member 6 and the side wall 2 of the cylinder block 1, a gas-liquid separation chamber 3a is defined, which separates the oil in the blow-by gas. The gas-liquid separation chamber 3a is the space on the inner periphery (inside) of the protruding wall 5. The cover member 6 is attached to the side wall 2 of the cylinder block 1 to form the oil separator 3.

[0017] As shown in FIG. 4, the cover member 6 has a first mounting surface 8 fixed to the tip surface 5a of the protruding wall 5, and a second mounting surface 9 fixed to the back surface 4b of the flange 4 of the cylinder block 1.

[0018] The first mounting surface 8 is formed in a continuous annular shape so as to face the entire periphery of the tip surface 5a of the protruding wall 5. The first mounting surface 8 is fixed to the protruding wall 5 by a plurality of first bolts 21 (see FIG. 6 described later). The cover member 6 is formed with a plurality of first bolt through holes 11 serving as bolt insertion holes that open perpendicular to the first mounting surface 8, and a plurality of second bolt through holes 12 that open perpendicular to the second mounting surface 9. The first bolt through holes 11 have a hole diameter (hole diameter) that allows the first bolts 21 to pass through, and are formed to have a diameter larger than the bolt diameter of the first bolts 21 (for example, 1 mm larger).

[0019] An annular groove 14 is formed in the first mounting surface 8, in which a sealant 13 is disposed to provide a liquid-tight seal between the first mounting surface 8 and the tip end surface 5a of the protruding wall 5. The groove 14 is formed so as to be located closer to the inner periphery of the first mounting surface 8 than the first bolt through-hole 11.

[0020] As shown in FIG. 3, the seal material 13 is disposed in the groove portion 14 so as to be continuous over the entire circumference. The seal material 13 is positioned between the first mounting surface 8 and the side wall 2 of the cylinder block 1, and provides a continuous, liquid-tight seal around the entire circumference of the gas-liquid separation chamber 3a. More specifically, the seal material 13 is positioned between the first mounting surface 8 and the tip surface 5a of the protruding wall 5. The seal material 13 has positioning protrusions 13a formed at three locations in the circumferential direction. In other words, the groove portion 14 has recesses 14a formed at three locations corresponding to the protrusions 13a. Furthermore, the seal material 13 has a circular cross section as shown in FIG. 5. FIG. 5 is a cross-sectional view taken along line AA in FIG. 4.

[0021] 2 and 3, the second mounting surface 9 is formed so as to be perpendicular to the first mounting surface 8. The second mounting surface 9 is fixed to the rear surface 4b of the flange 4 by a plurality of second bolts 22 (see FIG. 6 described later).

[0022] That is, the cover member 6 is fixed to the cylinder block 1 at two surfaces, that is, the first attachment surface 8 and the second attachment surface 9.

[0023] Note that reference numeral 15 in Fig. 1 denotes an inlet for blow-by gas introduced into the oil separator 3. Reference numeral 16 in Fig. 1 denotes an outlet for blow-by gas introduced into the oil separator 3. Reference numeral 17 in Fig. 1 denotes a block-side first bolt through-hole that overlaps with the first bolt through-hole 11. Reference numeral 18 in Fig. 1 denotes a block-side second bolt through-hole that overlaps with the second bolt through-hole 12.

[0024] The blow-by gas inlet 15 is located closer to the lower deck of the cylinder block 1 than the blow-by gas outlet 16 in the vertical direction along the cylinder axis. The blow-by gas inlet 15 is located closer to the upper deck of the cylinder block 1, to which a cylinder head (not shown) is attached, than the blow-by gas outlet 16 in the vertical direction along the cylinder axis. In other words, the blow-by gas inlet 15 and the blow-by gas outlet 16 are formed at positions offset from each other in the cylinder row direction of the cylinder block 1.

[0025] The gas-liquid separation chamber 3a, which is the internal space of the oil separator 3, has a so-called labyrinth structure with walls protruding from the side wall 2 of the cylinder block 1, so as to promote gas-liquid separation of the blow-by gas.

[0026] In the internal combustion engine of the above-described embodiment, the cover member 6 is fastened to the leading end surface 5a of the protruding wall 5 of the cylinder block 1 and to the flange 4 at the rear end of the cylinder block 1. In other words, in the internal combustion engine, the cover member 6 is fastened to two different surfaces of the cylinder block 1, that is, the side wall 2 and the flange 4.

[0027] Therefore, the cover member 6 can improve the overall rigidity of the internal combustion engine, and can suppress vibration response.

[0028] In an internal combustion engine, by giving the cover member 6 that constitutes the oil separator 3 the function of supporting the flange 4, weight and size can be reduced, thereby achieving lower costs and space savings, compared to when a member is set (provided) solely for the purpose of reinforcing the rigidity of the flange 4.

[0029] Compared to the case where a member is set (provided) solely for the purpose of reinforcing the rigidity of the flange 4, the internal combustion engine does not require the setting of a boss portion used when fastening the member solely for the purpose of reinforcing the rigidity of the flange 4 to the cylinder block 1, and overall, the volume of the oil separator 3 set in the side wall 2 of the cylinder block 1 can be easily secured.

[0030] Furthermore, in the internal combustion engine, the gap between the first mounting surface 8 of the cover member 6 and the tip surface 5a of the protruding wall 5 is sealed with a sealing material 13 having a circular cross section, so that twisting or tilting of the sealing material 13 can be minimized when the cover member 6 is attached to the side wall 2 of the cylinder block 1.

[0031] The work of attaching the cover member 6 to the cylinder block 1 is carried out with the cylinder block 1 held in a position where the direction in which the cylinders are aligned in the cylinder block 1 is aligned vertically, as shown in Figure 6. Figure 6 is an explanatory diagram showing the position in which the cover member 6 is attached to the cylinder block 1.

[0032] 6, the cover member 6 is temporarily fastened to the cylinder block 1 with the first bolt 21. When attaching the cover member 6 to the cylinder block 1, the second attachment surface 9 of the cover member 6 is placed on the back surface 4b of the flange 4, and the cover member 6 is slid toward the side wall 2 of the cylinder block 1 on which the protruding wall 5 is formed, and the first attachment surface 8 is fixed to the tip surface 5a of the protruding wall 5.

[0033] Thereafter, the second mounting surface 9 of the cover member 6 is pressed against the back surface 4b of the flange 4 using predetermined auxiliary bolts (not shown) or the like. At this time, the cover member 6 slides slightly toward the flange 4 along the cylinder row direction of the cylinder block 1. Next, all of the first bolts 21 are fully tightened, and the cover member 6 is fastened to the side wall 2 of the cylinder block 1. The above-mentioned auxiliary bolts or the like are removed, for example, after all of the first bolts 21 have been fully tightened. Finally, the cover member 6 is fastened to the flange 4 with the second bolts 22. The second bolts 22 are, for example, co-tightened with other components attached to the rear end of the cylinder block 1. Note that when fastening the cover member 6 to the flange 4 with the second bolts 22, the orientation of the cylinder block 1 does not have to be such that the cylinder row direction coincides with the vertical direction.

[0034] By attaching the cover member 6 to the cylinder block 1 in this manner, the cover member 6 is attached to the cylinder block 1 while being placed on the back surface 4b of the flange 4, and therefore can be easily fixed to the cylinder block 1 without falling off the flange 4.

[0035] 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.

[0036] For example, the first bolt through-hole 11 formed in the cover member 6 may be formed as an elongated hole extending along the cylinder row direction of the cylinder block 1. When the cover member 6 is fixed to the flange 4 with the second bolt 22, the axial force of the second bolt 22 presses the cover member 6 towards the flange 4 in the cylinder row direction of the cylinder block 1. If the first bolt through-hole 11 of the cover member 6 is formed as an elongated hole extending along the cylinder row direction of the cylinder block 1, interference between the first bolt 21 and the first bolt through-hole 11 can be more reliably avoided when the second bolt 22 is tightened to fix the cover member 6 to the flange 4. [Explanation of symbols]

[0037] 1...Cylinder block 2…Side wall 3...Oil separator 4...Flange 4a…Surface 4b...back side 5…Protruding wall 5a…Tip surface 6...Cover member 7...Bolt boss part 8...First mounting surface 9...Second mounting surface 11...First bolt through hole 12...Second bolt through hole 13...Sealing material 13a...Protrusion 14...Groove 14a...recess 15...Entrance 16…Discharge port 21...First bolt 22...Second bolt

Claims

1. a cylinder block having a flange formed on an outer periphery at one end in the cylinder row direction, the flange being adapted to attach other components, and the flange protruding outward; a cover member attached to a side wall of the cylinder block to form an oil separator between the cover member and the side wall, the cover member has a first mounting surface that is attached to a side wall of the cylinder block and a second mounting surface that is attached to the flange of the cylinder block, and the second mounting surface is formed so as to be perpendicular to the first mounting surface.

2. 2. The internal combustion engine according to claim 1, wherein bolt insertion holes, into which bolts that pass through the cover member and attach the cover member to the side wall of the cylinder block are inserted, are formed as elongated holes extending along the direction in which the cylinders are aligned.

3. 3. The internal combustion engine according to claim 2, further comprising a seal member having a circular cross section, which is positioned between the first mounting surface and the side wall of the cylinder block and seals the periphery of the gas-liquid separation chamber of the oil separator.

4. 4. The internal combustion engine according to claim 1, wherein the cover member is made of a metal material.

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