Internal combustion engine

Abstract

The utility model provides a kind of internal combustion engine. In the internal combustion engine, a falling oil hole for making engine oil flow down towards oil pan is provided in cylinder head and cylinder block, and in the falling oil hole, a spacer assembly for forming a deceleration oil passage in the oil passage where the engine oil flows down is inserted, wherein the deceleration oil passage extends in a direction crossing the vertical direction to reduce the flow rate of the engine oil. Based on the above structure of the utility model, the mixing of air bubbles into the engine oil can be inhibited.

Description

Technical Field

[0001] This utility model relates to internal combustion engines. Background Technology

[0002] Traditionally, in internal combustion engines used in automobiles, a cylinder head is mounted above the cylinder block, and a crankcase is mounted below the cylinder block. An oil pan, containing engine oil, is also mounted below the crankcase.

[0003] During the operation of an internal combustion engine, the oil pump draws engine oil from the oil pan, and the drawn-up engine oil is supplied to various parts of the internal combustion engine. This lubricates the sliding parts inside the engine.

[0004] After lubricating the sliding parts, the engine oil flows through the oil drain holes located in the cylinder head and cylinder block, and then flows back to the oil pan for recycling. Most existing oil drain holes are circular passageways that extend vertically from the cylinder head to the cylinder block.

[0005] Therefore, the engine oil flowing through the oil drain hole drips down from the bottom of the cylinder block at a relatively high speed due to gravity, and then drips onto the surface of the engine oil in the oil pan. At this time, because the engine oil is falling at a high speed, when the falling engine oil collides with the oil surface in the oil pan, the oil surface will fluctuate and generate air bubbles, which may cause air bubbles to mix into the engine oil.

[0006] Additionally, as the engine oil flows through the oil drain hole, the heat in the oil is carried away by the cylinder head and cylinder block, thus cooling it down. However, due to its high flow velocity and short contact time with the cylinder head and cylinder block, its effectiveness in reducing engine oil temperature is limited. When the engine oil temperature is high, its viscosity decreases, which is also a reason why air bubbles are more likely to form.

[0007] If air bubbles are mixed in the engine oil, it may result in insufficient oil supply to various parts of the internal combustion engine, or cause the oil pump to malfunction due to so-called "vapor lock". Utility Model Content

[0008] In view of the above situation, the purpose of this utility model is to provide an internal combustion engine that can suppress the mixing of air bubbles into the engine oil.

[0009] As a technical solution to the above-mentioned technical problems, this utility model provides an internal combustion engine. In this internal combustion engine, an oil drain hole is provided in the cylinder head and cylinder block for allowing engine oil to flow down toward the oil pan. The feature is that a spacer assembly is inserted in the oil drain hole to form a deceleration oil passage in the oil passage in which the engine oil flows down. The deceleration oil passage extends in a direction intersecting the vertical direction to reduce the flow rate of the engine oil.

[0010] The advantage of this internal combustion engine with the above-described structure is its ability to suppress air bubbles from entering the engine oil. Specifically, when the engine oil flows down into the oil pan, it passes through a deceleration oil passage formed by the spacer assembly. Since this deceleration oil passage extends in a direction intersecting the vertical, the engine oil flowing through it does not accelerate due to gravity; instead, it decelerates. Therefore, the falling speed of the engine oil dripping from the lower end of the cylinder block (lower end of the oil drain hole) onto the surface of the engine oil in the oil pan is reduced, thereby suppressing the formation of air bubbles on the surface of the engine oil in the oil pan. Furthermore, by reducing the flow velocity of the engine oil inside the cylinder head and cylinder block, the heat carried away by the cylinder head and cylinder block is increased, effectively lowering the engine oil temperature. As the engine oil temperature decreases, its viscosity increases, further suppressing air bubble formation.

[0011] Furthermore, in the aforementioned internal combustion engine of this utility model, preferably, the spacer assembly is assembled from a first spacer and a second spacer that are separated from each other in a direction intersecting the vertical direction; on the surface of the first spacer facing the second spacer, protrusions and recesses are alternately formed in the vertical direction; on the surface of the second spacer facing the first spacer, recesses facing the protrusions of the first spacer and protrusions facing the recesses of the first spacer are formed in the vertical direction; the space above the protrusions of the first spacer and the space above the protrusions of the second spacer respectively constitute the deceleration oil passage.

[0012] Based on this structure, vertically extending oil passages and deceleration oil passages extending in directions intersecting the vertical direction are alternately formed inside the spacer assembly. Thus, engine oil accelerated in the vertically extending oil passages is decelerated in the deceleration oil passages, and this acceleration and deceleration are repeated alternately. In this way, because the engine oil is decelerated at multiple points, the dripping speed of the engine oil falling from the lower end of the cylinder block onto the surface of the oil pan is reduced.

[0013] In addition, in the internal combustion engine of the present invention, preferably, a protrusion is provided on at least one of the face of the first spacer facing the second spacer and the face of the second spacer facing the first spacer. The protrusion abuts against the spacer on the opposite side with a predetermined interval between the convex part of the first spacer and the concave part of the second spacer, and between the convex part of the second spacer and the concave part of the first spacer.

[0014] Based on this structure, when assembling the first spacer and the second spacer to form a spacer assembly, an oil passage for engine oil to flow down can be formed between the first spacer and the second spacer by making the protrusion provided on at least one of the first spacer and the second spacer abut against the spacer on its opposite side. Attached Figure Description

[0015] Figure 1 This is a longitudinal sectional view of an internal combustion engine according to an embodiment of the present invention.

[0016] Figure 2 This is a perspective view showing the first spacer of the spacer assembly in an embodiment of the present invention.

[0017] Figure 3 This is a perspective view showing the second spacer of the spacer assembly in an embodiment of the present invention.

[0018] Figure 4 This is a top view showing the state of the first spacer and the second spacer after combination in an embodiment of this utility model.

[0019] Figure 5 This is a schematic diagram illustrating the flow of engine oil inside the separator assembly in an embodiment of the present invention. Detailed Implementation

[0020] The embodiments of this utility model will now be described with reference to the accompanying drawings.

[0021] Figure 1 This is a longitudinal cross-sectional view of the internal combustion engine 1 in this embodiment. Figure 1 As shown, the internal combustion engine 1 of this embodiment includes a cylinder block 2, a cylinder head 3, a crankcase 4, and an oil pan 5.

[0022] A cylinder head 3 is mounted above the cylinder block 2. A crankcase 4 is mounted below the cylinder block 2. An oil pan 5 is mounted below the crankcase 4. Engine oil 0 is stored in the oil pan 5.

[0023] A cylinder bore 21 is provided inside the cylinder block 2. A reciprocating piston 22 is installed inside the cylinder bore 21.

[0024] A crankshaft 41 is assembled inside the crankcase 4. The crankshaft 41 is connected to the piston 22 via a connecting rod 42.

[0025] A combustion chamber 31 is formed by isolating the cylinder bore 21, piston 22, and cylinder head 3.

[0026] The cylinder head 3 is provided with an intake port 32 for introducing intake air into the combustion chamber 31 and an exhaust port 33 for discharging exhaust gas from the combustion chamber 31. The intake port 32 is opened and closed by the reciprocating motion of the intake valve 35 (which accompanies the rotation of the intake camshaft 34). The intake port 32 is open during the intake stroke of the internal combustion engine 1. The exhaust port 33 is opened and closed by the reciprocating motion of the exhaust valve 37 (which accompanies the rotation of the exhaust camshaft 36). The exhaust port 33 is open during the exhaust stroke of the internal combustion engine 1.

[0027] During the expansion stroke of the internal combustion engine 1, the piston 22 is pushed down due to the combustion of the gas mixture in the combustion chamber 31. Then, the piston 22 reciprocates through repeated exhaust stroke, intake stroke, compression stroke, and expansion stroke. The crankshaft 41 rotates along with the reciprocating motion of the piston 22, thereby causing the internal combustion engine 1 to output driving force.

[0028] During the operation of the internal combustion engine 1, the oil pump (not shown) operates to draw engine oil O from the oil pan 5, and the drawn engine oil O is supplied to various parts of the internal combustion engine 1. This lubricates the sliding parts inside the internal combustion engine 1.

[0029] After lubricating the various sliding parts, the engine oil O flows through the oil drain holes 6 provided in the cylinder head 3 and cylinder block 2, and then flows back to the oil pan 5 to be recycled.

[0030] In this embodiment, a spacer assembly 7 is inserted into the oil drain hole 6. By allowing the engine oil O to flow through the deceleration oil passage formed by the spacer assembly 7, the speed of the engine oil O flowing into the oil pan 5 is reduced.

[0031] The spacer assembly 7 will be described below.

[0032] The spacer assembly 7 is assembled from the first spacer 8 and the second spacer 9. Figure 2 This is a perspective view showing the first spacer 8 in this embodiment. Figure 3 This is a perspective view showing the second spacer 9 in this embodiment.

[0033] like Figure 2As shown, the first spacer 8 is configured as a semi-cylindrical shape, having a back surface 81 that is arc-shaped when viewed from above in the longitudinal direction (vertical direction) of the first spacer 8, and an oil passage forming surface 82 provided with a protrusion 83 and a recess 84. Here, the dimension of the first spacer 8 in the longitudinal direction is the same as the overall length dimension of the oil drain hole 6.

[0034] The radius of curvature of the outer periphery of the cross-section (parallel to the horizontal direction) of the first spacer 8 is the same as the radius of the oil drain hole 6. Therefore, when the first spacer 8 is inserted into the oil drain hole 6, its back surface 81 is in close contact with the inner circumferential surface of the oil drain hole 6 (see...). Figure 1 ).

[0035] The oil passage forming surface 82 is the surface facing the second spacer 9 when the spacer assembly 7 is inserted into the oil drain hole 6. On the oil passage forming surface 82, protrusions 83 and recesses 84 are alternately formed in the vertical direction. Specifically, a recess 84 is formed at the upper end of the oil passage forming surface 82, a protrusion 83 is formed below the recess 84, and a recess 84 is formed below the protrusion 83. Thus, protrusions 83 and recesses 84 are alternately formed in the vertical direction on the oil passage forming surface 82.

[0036] The upper surface 83a and lower surface 83b of the protrusion 83 are flat surfaces extending horizontally (in a direction perpendicular to the vertical direction). The front surface 83c of the protrusion 83 is a flat surface extending vertically (in a direction perpendicular to the horizontal direction). The horizontal protrusion of the protrusion 83 is set such that, when viewed from above (top view), it can overlap with the protrusion 93 provided on the second spacer 9 (described later) (overlapping at a predetermined interval in the vertical direction).

[0037] The bottom surface 84a of the recess 84 is a flat surface that extends vertically (in a direction perpendicular to the horizontal direction). The horizontal recess 84 is recessed to a size that allows it to be spaced apart from the front surface 93c of the protrusion 93 provided on the second spacer 9, as described later, by a predetermined interval.

[0038] like Figure 3 As shown, the second spacer 9 is also configured as a semi-cylindrical shape, having a back surface 91 that is arc-shaped when viewed from above in the longitudinal direction (vertical direction) of the second spacer 9, and an oil passage forming surface 92 provided with a protrusion 93 and a recess 94. The dimension of the second spacer 9 in the longitudinal direction is also consistent with the overall length dimension of the oil drain hole 6.

[0039] The radius of curvature of the outer periphery of the cross-section (parallel to the horizontal direction) of the second spacer 9 is the same as the radius of the oil drain hole 6. Therefore, when the second spacer 9 is inserted into the oil drain hole 6, its back surface 91 is in close contact with the inner circumferential surface of the oil drain hole 6 (see...). Figure 1 ).

[0040] The oil passage forming surface 92 is the surface facing the first spacer 8 when the spacer assembly 7 is inserted into the oil drain hole 6. On the oil passage forming surface 92, protrusions 93 and recesses 94 are alternately formed in the vertical direction. Specifically, a protrusion 93 is formed at the upper end of the oil passage forming surface 92, a recess 94 is formed below the protrusion 93, and a protrusion 93 is formed below the recess 94. Thus, protrusions 93 and recesses 94 are alternately formed in the vertical direction on the oil passage forming surface 92.

[0041] The upper surface 93a and lower surface 93b of the protrusion 93 are flat surfaces extending horizontally (in a direction perpendicular to the vertical direction). The front surface 93c of the protrusion 93 is a flat surface extending vertically (in a direction perpendicular to the horizontal direction). The horizontal protrusion of the protrusion 93 is set such that, when viewed from above (top view), it can overlap with the protrusion 83 provided on the first spacer 8 (overlapping at a predetermined interval in the vertical direction).

[0042] The bottom surface 94a of the recess 94 is a flat surface that extends vertically (in a direction perpendicular to the horizontal direction). The horizontal recess 94 is recessed to a size that can be spaced apart from the front surface 83c of the protrusion 83 provided on the first spacer 8 by a predetermined distance.

[0043] In addition, such as Figure 2 As shown, a pair of protrusions 84b are provided in the recess 84 at the upper end of the oil passage forming surface 82 of the first spacer 8. The protrusions 84b protrude horizontally from the bottom surface 84a of the recess 84. The protrusion dimension of the protrusions 84b is set such that, when the first spacer 8 and the second spacer 9 are assembled into the spacer assembly 7, the protrusions 84b can abut against the front surface 93c of the protrusion 93 on the opposite side (the second spacer 9), thereby leaving a predetermined distance between the front surface 83c of the protrusion 83 of the first spacer 8 and the bottom surface 94a of the recess 94 of the second spacer 9, and between the front surface 93c of the protrusion 93 of the second spacer 9 and the bottom surface 84a of the recess 84 of the first spacer 8.

[0044] Figure 4This is a top view showing the state after the first spacer 8 and the second spacer 9 are combined in this embodiment, showing the state in which a pair of protrusions 84b provided on the first spacer 8 abut against the front surface 93c of the protrusion 93 of the second spacer 9. Thus, in the state where the first spacer 8 and the second spacer 9 are combined, the top view shape of the outer peripheral surface of the spacer assembly 7, which is formed by the back surface 81 of the first spacer 8 and the back surface 91 of the second spacer 9, is circular, and its outer diameter is the same as the inner diameter of the oil drain hole 6. Therefore, by inserting the spacer assembly 7 into the oil drain hole 6 that penetrates the cylinder head 3 and the cylinder block 2 from the top, the spacer assembly 7 can be installed in the oil drain hole 6 with the back surface 81 of the first spacer 8 and the back surface 91 of the second spacer 9 respectively in close contact with the inner peripheral surface of the oil drain hole 6.

[0045] In addition, as a structure to prevent the spacer assembly 7 from falling out of the oil drain hole 6 when the spacer assembly 7 is installed in the oil drain hole 6, for example, a protrusion (not shown) can be provided on the inner surface of the oil drain hole 6. The spacer assembly 7 can be supported by the protrusion to prevent it from falling out.

[0046] Thus, with the spacer assembly 7 installed in the oil drain hole 6, as follows: Figure 1 and Figure 5 (As shown, the flow of engine oil O flowing down from inside the spacer assembly 7 is illustrated.) An oil passage is formed between the first spacer 8 and the second spacer 9.

[0047] Specifically, an oil passage for supplying engine oil O is formed by alternately forming a vertical oil passage A extending in the vertical direction and a deceleration oil passage B extending in the horizontal direction.

[0048] The vertical oil passage A is formed by the space between the front surface 83c of the protrusion 83 of the first spacer 8 and the bottom surface 94a of the recess 94 of the second spacer 9, and the space between the front surface 93c of the protrusion 93 of the second spacer 9 and the bottom surface 84a of the recess 84 of the first spacer 8.

[0049] The deceleration oil circuit B is formed by the space above the protrusion 83 of the first spacer 8 and the space above the protrusion 93 of the second spacer 9.

[0050] Based on this structure, when the engine oil O, after lubricating the sliding parts of the internal combustion engine 1, flows down towards the oil pan 5, as... Figure 5As shown by the dotted arrows, engine oil O flows alternately through the vertical oil passage A and the deceleration oil passage B. That is, when engine oil O flows down towards the oil pan 5, its flow rate accelerates in the vertical oil passage A but decelerates in the deceleration oil passage B, and this acceleration and deceleration alternate repeatedly. Thus, by decelerating the engine oil O at multiple points, the falling speed of the engine oil O from the lower end of the cylinder block 2 onto the surface of the engine oil O in the oil pan 5 is reduced. Therefore, the formation of air bubbles on the surface of the engine oil O in the oil pan 5 can be suppressed. Furthermore, since the flow rate of engine oil O in the oil passages can be reduced, the heat carried away by the cylinder head 3 and cylinder block 2 can be increased, thereby effectively reducing the temperature of the engine oil O. By reducing the temperature of the engine oil O, its viscosity can be increased, thereby also achieving the effect of suppressing air bubble formation.

[0051] However, this invention is not limited to the embodiments described above, and various applications and modifications can be implemented. For example, in the above embodiments, the spacer assembly 7 is inserted into the entire area of ​​the oil drain hole 6 formed on the cylinder head 3 and the cylinder block 2. However, this invention is not limited to this, and the spacer assembly 7 may also be inserted only into a portion of the oil drain hole 6.

[0052] Furthermore, in the above embodiment, the upper surface 83a of the protrusion 83 of the first spacer 8 and the upper surface 93a of the protrusion 93 of the second spacer 9 are respectively configured as flat surfaces extending in the horizontal direction. However, the present invention is not limited to this, and these upper surfaces (83a, 93a) may also be configured as inclined surfaces. As for the direction of inclination, it may be inclined downward relative to the flow direction of engine oil O, or it may be inclined upward relative to the flow direction of engine oil O.

[0053] In addition, in the above embodiment, two protrusions 84b for ensuring the oil passage in the spacer assembly 7 are provided on the first spacer 8. However, the present invention is not limited to this, and the protrusions may also be provided on the second spacer 9, or protrusions may be provided on both the first spacer 8 and the second spacer 9.

Claims

1. An internal combustion engine, wherein oil drain holes are provided in the cylinder head and cylinder block for allowing engine oil to flow down toward the oil pan, characterized in that: An intervalve assembly is inserted into the oil drain hole to form a deceleration oil passage in the oil passage flowing down the engine oil, wherein the deceleration oil passage extends in a direction intersecting the vertical direction to reduce the flow rate of the engine oil.

2. The internal combustion engine as described in claim 1, characterized in that: The spacer assembly is composed of a first spacer and a second spacer that are separated from each other in a direction intersecting the vertical direction; On the surface of the first spacer facing the second spacer, protrusions and recesses are alternately formed in the vertical direction; On the surface of the second spacer facing the first spacer, a recess facing the protrusion of the first spacer and a protrusion facing the recess of the first spacer are formed in the vertical direction. The space above the protrusion of the first spacer and the space above the protrusion of the second spacer respectively constitute the deceleration oil circuit.

3. The internal combustion engine as described in claim 2, characterized in that: A protrusion is provided on at least one of the faces of the first spacer facing the second spacer and the faces of the second spacer facing the first spacer. The protrusion abuts against the spacer on the opposite side with a predetermined interval between the convex part of the first spacer and the concave part of the second spacer, and between the convex part of the second spacer and the concave part of the first spacer.

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