JP2007187138A - Internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an internal combustion engine capable of effectively cooling a division wall between adjacent cylinder bores. <P>SOLUTION: The internal combustion engine 1 includes cylinders 21, 22 having the cylinder bores 211, 221 for housing pistons, and intake ports 321, 331 and exhaust ports 322, 332 connected to the cylinder bores 211, 221. At least a pair of the cylinders 21, 22 is lined up. A straight line (a bore center axis) I is drawn connecting centers of a pair of adjacent cylinder bores 211, 221 as seen from a perpendicular cross-sectional view with respect to central axes of the cylinder bores 211, 221. At least one of the intake ports 321, 331 connected to the cylinder bores 211, 221 is on the bore center axis I, and it is positioned toward a division wall side between the pair of cylinder bores 211, 221 than the centers of the pair of cylinder bores 211, 221. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an internal combustion engine, and more particularly to an internal combustion engine that can effectively cool a partition wall between adjacent cylinder bores.

  In a multi-cylinder internal combustion engine, a partition wall between adjacent cylinder bores becomes hot due to combustion heat during engine operation. When the temperature of the partition wall reaches a predetermined upper limit temperature (for example, the oil volatilization temperature), there arises a problem that the oil consumption is rapidly deteriorated.

  For this reason, in the conventional internal combustion engine, a cooling water passage is formed in the partition between adjacent cylinder bores, and the partition between the cylinder bores is cooled by the cooling water flowing through this passage. Thereby, the deterioration of the oil consumption resulting from the temperature rise of a partition is suppressed. As a conventional internal combustion engine employing such a configuration, a technique described in Patent Document 1 is known.

  However, in recent internal combustion engines, the pitch between cylinder bores tends to be shortened in order to make the engine compact. For this reason, the partition between cylinder bores becomes thin, and a cooling water passage having a sufficient flow path cross-sectional area may not be formed. Further, if the cooling water passage is forcibly formed in such a thin partition wall, the rigidity of the partition wall may be lowered and the reliability of the engine may be affected.

  For example, the technology described in Patent Document 2 is known as a conventional internal combustion engine that affects the patentability of the invention according to this application. A conventional internal combustion engine (arrangement of intake and exhaust ports in an internal combustion engine) is disposed at a position opposite to the cylinder, a first intake port coupled to the cylinder, and a diagonal line of the cylinder with respect to the first intake port. And a second intake port coupled to the cylinder and at least one exhaust port.

JP 2003-120289 A JP 11-287153 A

  An object of the present invention is to provide an internal combustion engine that can effectively cool a partition wall between adjacent cylinder bores.

  To achieve the above object, an internal combustion engine according to the present invention includes a cylinder having a cylinder bore for housing a piston, an intake port and an exhaust port connected to the cylinder bore, and at least a pair of the cylinders in series. The internal combustion engine is configured to draw a straight line (hereinafter referred to as a bore center axis) l connecting the centers of a pair of adjacent cylinder bores in a cross-sectional view perpendicular to the center axis of the cylinder bore. The intake port connected to at least one of the cylinder bores is located on the bore center axis l and on the partition side between the pair of cylinder bores with respect to the center of the cylinder bore.

  In this internal combustion engine, since the intake port is disposed in the vicinity of the partition wall between the cylinder bores, there is an advantage that the partition wall between the cylinder bores is effectively cooled by the relatively low temperature air-fuel mixture sucked from the intake port.

  The internal combustion engine according to the present invention includes a cylinder having a cylinder bore for housing a piston, an intake port and an exhaust port connected to the cylinder bore, and at least a pair of the cylinders in series. A straight line (hereinafter referred to as a bore center axis) l connecting the centers of a pair of adjacent cylinder bores in a cross-sectional view perpendicular to the center axis of the cylinder bore, and the bore center axis l When taking the intersection P with the partition wall between the pair of cylinder bores, the intake port connected to at least one of the cylinder bores is located closer to the intersection P than the exhaust port connected to the cylinder bore. To do.

  In this internal combustion engine, since the intake port is disposed in the vicinity of the partition wall between the cylinder bores, there is an advantage that the partition wall between the cylinder bores is effectively cooled by the relatively low temperature air-fuel mixture sucked from the intake port.

  Further, in the internal combustion engine according to the present invention, the intake port connected to one of the adjacent cylinder bores and the intake port connected to the other cylinder bore are on the central axis of the cylinder bore. On the other hand, they are arranged with a partition wall between the pair of cylinder bores in a vertical cross-sectional view.

  In this internal combustion engine, the substantially center of the partition wall is cooled from both sides by the air-fuel mixture sucked from the pair of intake ports. Thereby, there exists an advantage by which the partition between cylinder bores is cooled more effectively.

  Further, in the internal combustion engine according to the present invention, a pair of the intake ports are connected to one cylinder bore, and these intake ports are bored in a cross-sectional view perpendicular to the central axis of the cylinder bore. Arranged on the center axis l.

  In this internal combustion engine, when the above-described partition walls are present on both sides of one cylinder bore (for example, in the case of an engine having three or more cylinders in series), both partition walls are cooled by the air-fuel mixture sucked from the intake port. There is.

  In the internal combustion engine according to the present invention, a pair of the exhaust ports are connected to one cylinder bore, and the exhaust ports and the pair of intake ports are alternately arranged around the central axis of the cylinder bore. And the one exhaust port is displaced in the axial direction of the bore center shaft l with respect to the other exhaust port.

  In this internal combustion engine, each intake valve of a pair of intake ports and each exhaust valve of a pair of exhaust ports can be driven by a single camshaft. Thereby, there exists an advantage by which the structure of a valve operating system is simplified.

  In the internal combustion engine according to the present invention, a cooling water passage is formed on the outer periphery of the arranged cylinder group, and the exhaust port is arranged closer to the cooling water passage than the intake port.

  In this internal combustion engine, the combustion gas discharged in the exhaust stroke causes the wall surface on the exhaust port side of the cylinder bore to be hotter than the wall surface on the intake port side. Therefore, there is an advantage that the cylinder is effectively cooled by disposing the exhaust port closer to the cooling water passage than the intake port.

  In the internal combustion engine according to the present invention, since the intake port is disposed in the vicinity of the partition wall between the cylinder bores, there is an advantage that the partition wall between the cylinder bores is effectively cooled by the relatively low temperature air-fuel mixture sucked from the intake port. is there.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. The constituent elements of this embodiment include those that can be easily replaced by those skilled in the art or those that are substantially the same. In addition, a plurality of modifications described in this embodiment can be arbitrarily combined within a range obvious to those skilled in the art.

[Internal combustion engine]
FIG. 1 is a block diagram showing an internal combustion engine according to an embodiment of the present invention. 2 and 3 are an AA sectional view (FIG. 2) and a BB sectional view (FIG. 3) showing the internal combustion engine shown in FIG. FIG. 4 is a block diagram showing a modification of the internal combustion engine shown in FIG. FIG. 5 is a conceptual diagram showing a cooling water passage on the combustion chamber side of the internal combustion engine shown in FIG. FIG. 1 shows the positional relationship between the cylinder bores 211 and 221 and the intake ports 321 and 331 and the exhaust ports 322 and 332 in a plan view of the cylinder block 2 as viewed from the cylinder head 3 side.

  The internal combustion engine 1 includes a cylinder block 2, a cylinder head 3, and a valve train 4 (see FIGS. 1 to 3).

  The cylinder block 2 is a component that constitutes the main body of the internal combustion engine 1, and is configured by integrally forming a crankcase (not shown) and a plurality of members including a plurality of cylinders 21 and 22 (see FIGS. 1 and 2). ). In this cylinder block 2, at least a pair of cylinders 21 and 22 are arranged adjacent to each other. For example, in the in-line four-cylinder internal combustion engine 1, four cylinders are arranged linearly (in series) while being adjacent to each other (not shown). In addition, cylinder bores 211 and 221 are formed in the cylinders 21 and 22, respectively. In these cylinder bores 211 and 221, pistons 5 are respectively housed so as to be able to reciprocate.

  The cylinder head 3 is a cover-like component disposed on the upper portion of the cylinder block 2 and is fastened to the cylinder block 2 by bolts (not shown). In the cylinder head 3, a plurality of combustion chambers 31 and 32 are formed corresponding to the cylinders 21 and 22, respectively. An intake port 321 (331) and an exhaust port 322 (332) are formed in the combustion chamber 31 (32), respectively. Specifically, a pair of intake ports 321, 321 (331, 331) and a pair of exhaust ports 322, 322 (332, 332) are formed for one combustion chamber 31 (32), respectively.

  In this embodiment, in describing the positional relationship between the cylinder bores 211 and 221 and the intake ports 321 and 331 and the exhaust ports 322 and 332, the openings of the intake ports 321 and 331 and the exhaust ports 322 and 332 with respect to the combustion chambers 31 and 32 are provided. These parts are simply referred to as intake ports 321 and 331 and exhaust ports 322 and 332.

  The valve train 4 includes an intake valve 41, an exhaust valve 42, an intake side intermediate mechanism 43, an exhaust side intermediate mechanism 44, and a camshaft 45. An intake valve 41 is provided for each intake port 321, 331. The intake valve 41 is connected to the camshaft 45 via the intake side intermediate mechanism 43. An exhaust valve 42 is provided for each exhaust port 322, 332. The exhaust valve 42 is connected to the camshaft 45 via the exhaust side intermediate mechanism 44. The camshaft 45 is connected to a crankshaft (not shown) and is driven by power supplied from the crankshaft.

  In the internal combustion engine 1, when the camshaft 45 rotates during operation, the intake valve 41 and the exhaust valve 42 are driven at a predetermined valve timing to perform an opening / closing operation (see FIGS. 2 and 3). As a result, the combustion gas in the combustion chambers 31 and 32 is discharged to the outside via the exhaust ports 322 and 332 (exhaust stroke), and a new air-fuel mixture enters the combustion chambers 31 and 32 via the intake ports 321 and 331. Inhaled (intake stroke).

[Intake valve arrangement]
Here, a straight line connecting the centers of a pair of adjacent cylinder bores 211 and 221 (hereinafter referred to as a bore center axis) l in a cross-sectional view perpendicular to the center axis of the cylinder bores 211 and 221 (cylinders 21 and 22). (See FIG. 1). For example, in an in-line four-cylinder internal combustion engine, one bore center shaft 1 can be drawn for four in-line cylinders. At this time, the intake port 321 (331) connected to at least one of the cylinder bores 211 (221) is disposed on the side of the partition wall between the cylinder bores 211 and 221 on the bore center shaft 1 and from the center of the cylinder bore 211 (221). Is done. That is, at least one intake port 321 (331) is disposed near the center (intersection P) of the partition wall between the cylinder bores 211 and 221 when the cylinder bores 211 and 221 are viewed from the combustion chambers 31 and 32 side.

  Further, an intersection P between the bore center shaft l and the partition wall between the cylinder bores 211 and 221 is taken (see FIG. 1). Since this intersection point P is located at the approximate center of the partition wall between the cylinder bores 211 and 221, it is located at a position farther from a cooling water passage 24 described later than the other part of the partition wall. For this reason, at the position of this intersection point P, the partition wall between the cylinder bores 211 and 221 is not easily cooled by the cooling water flowing through the cooling water passage 24 and is likely to become high temperature when the internal combustion engine 1 is in operation. In relation to this intersection P, the intake port 321 (331) connected to at least one cylinder bore 211 (221) is closer to the intersection P than the exhaust port 322 (332) connected to this cylinder bore 211 (221). Be placed. Therefore, in the relationship between the intake port 321 (331) and the exhaust port 322 (332) in the same cylinder bore 211 (221), the intake port 321 (331) is more central than the exhaust port 322 (332) (intersection point). It is arranged at a position close to P).

  In these configurations, the intake port 321 (331) is disposed in the vicinity of the partition between the cylinder bores 211 and 221. Therefore, the air-fuel mixture sucked from the intake port 321 (331) is blown to the partition between the cylinder bores 211 and 221. It is easy to be done. The air-fuel mixture is at a lower temperature than the combustion gas discharged from the exhaust ports 322 and 332. Therefore, such a configuration has an advantage that the partition wall between the cylinder bores 211 and 221 is effectively cooled by the relatively low temperature air-fuel mixture sucked from the intake port 321 (331).

  In the internal combustion engine 1, the intake port 321 connected to one cylinder bore 211 of the pair of cylinder bores 211 and 221 and the intake port 331 connected to the other cylinder bore 221 are arranged on the central axis of the cylinder bores 211 and 221. On the other hand, they are arranged across a partition wall between the cylinder bores 211 and 221 in a vertical sectional view (see FIG. 1). That is, the intake ports 321 and 331 are respectively arranged on both sides of the partition wall. In such a configuration, the substantially center of the partition wall is cooled from both sides by the air-fuel mixture sucked from the intake ports 321 and 331. Thereby, there exists an advantage by which the partition between cylinder bores 211 and 221 is cooled more effectively.

  In the internal combustion engine 1, a pair of intake ports 331 and 331 are connected to one cylinder bore 221 (see FIG. 1). In addition, these intake ports 331 and 331 are arranged on the bore center shaft 1 in a cross-sectional view perpendicular to the central axes of the cylinder bores 211 and 221. In such a configuration, when the partition walls exist on both sides of one cylinder bore 221 (for example, in the case of an engine having three or more cylinders in series), both the partition walls are cooled by the air-fuel mixture sucked from the intake ports 331 and 331. There are advantages to being.

  For example, in the internal combustion engine 1 adopting a four-valve structure, a pair of intake ports 321 and 321 (331 and 331) and a pair of exhaust ports 322 and 322 (332 and 332) are provided for one cylinder bore 211 (221). Connected (see FIGS. 1 to 3). The intake ports 321 and 321 (331 and 331) and the exhaust ports 322 and 322 (332 and 332) are alternately arranged around the central axis of the cylinder bore 211 (221) with an interval of about 45 [deg]. The At this time, the pair of intake ports 321, 321 (331, 331) and the pair of exhaust ports 322, 322 (332, 332) face each other in the radial direction of the cylinder bore 211 (221). Further, the intake ports 321 and 321 (331 and 331) are arranged on the bore center axis 1 (in the vicinity of the intersection point P).

  Further, for example, in the internal combustion engine 1 adopting a three-valve structure, a pair of intake ports 321 and 321 (331 and 331) and a single exhaust port 322 (332) are connected to one cylinder bore 211 (221). (See FIG. 4). Also in this configuration, the intake ports 321 and 321 (331 and 331) are also arranged on the bore center axis 1 (in the vicinity of the intersection point P).

[Relationship with valve system]
Also, a pair of intake ports 321 and 321 (331, 331) and a pair of exhaust ports 322, 322 (332, 332) are alternately arranged around the central axis of the cylinder bore 211 (221), and each intake port 321 is provided. , 321 (331, 331) are arranged on the bore center axis l, the exhaust ports 322, 322 (332, 332) are preferably arranged offset with respect to the bore center axis l (see FIG. 1). ). That is, one exhaust port 322 (332) is arranged so as to be shifted in the axial direction of the bore center shaft l with respect to the other exhaust port 322 (332). In other words, it is preferable that the legs of the perpendicular line drawn from the center of each exhaust port 322, 322 (332, 332) to the bore center axis 1 are at different positions on the bore center axis l.

  In such a configuration, the intake valves 41 and 41 of the pair of intake ports 321 and 321 (331 and 331) and the exhaust valves 42 and 42 of the pair of exhaust ports 322 and 322 (332 and 332) are connected to one camshaft. 45 can be driven. Thereby, there exists an advantage by which the structure of the valve operating system 4 is simplified.

  For example, in the internal combustion engine 1, a single camshaft 45 is disposed above the combustion chambers 31 and 32 along the bore center axis l. An intake valve 41 and an exhaust valve 42 are connected to the camshaft 45 via intermediate mechanisms 43 and 44. At this time, since one exhaust port 322 (332) is arranged to be displaced in the axial direction of the bore center shaft l with respect to the other exhaust port 322 (332), each intermediate mechanism 43, 44 is connected to one The camshaft 45 can be connected. Thus, the intake valves 41 and 41 and the exhaust valves 42 and 42 are driven by the single camshaft 45.

  More specifically, the intake side intermediate mechanism 43 includes a lifter, and the intake valve 41 is opened by the camshaft 45 directly hitting the lifter (see FIG. 3). The exhaust side intermediate mechanism 44 includes a rocker arm 441 and a lash adjuster 442 (see FIG. 2). Further, the exhaust side intermediate mechanisms 44, 44 corresponding to the pair of exhaust valves 42, 41 are arranged shifted in the axial direction of the camshaft 45. In this configuration, when the camshaft 45 hits the rocker arm 441 directly, the exhaust valve 42 is pushed down through the lash adjuster 442 to open. With this configuration, the configuration of the valve train 4 is simplified.

[Relationship with cooling water passage]
In the internal combustion engine 1, a water jacket 23 is provided along the outer periphery of the arranged cylinders 21 and 22, and a cooling water passage 24 is formed by the water jacket 23. For example, the cooling water passage 24 is formed on the side of the cylinders 21 and 22 along the arrangement direction of the cylinders 21 and 22. When the internal combustion engine 1 is in operation, the cooling water flows through the cooling water passage 24 to cool the cylinders 21 and 22.

  In this embodiment, the water jacket 23 is opened on the upper surface of the cylinder block 2 (joint surface with the cylinder head 3) (open deck structure). The cooling water passage 24 is connected to a radiator (not shown) of the vehicle, and cooling water is supplied from this radiator.

  Here, when the internal combustion engine 1 is in operation, the exhausted combustion gas causes the wall surface on the exhaust port 322 (332) side of the cylinder bore 211 (221) to be hotter than the wall surface on the intake port 321 (331) side. Therefore, in the above configuration, it is preferable that the exhaust port 322 (332) is disposed closer to the cooling water passage 24 (outside) than the intake port 321 (331) (see FIG. 1). Thereby, there exists an advantage by which the cylinder 21 (22) is cooled effectively and the temperature rise of the cylinder 21 (22) is reduced.

  A cooling water passage (not shown) is also formed on the cylinder head 3 side along the arrayed combustion chambers 31 and 32 (see FIG. 5). And the cooling water flows through the side of the combustion chambers 31 and 32 group, whereby the vicinity of the combustion chambers 31 and 32 is cooled. Therefore, in the above configuration, since the exhaust port 322 (332) is located outside the intake port 321 (331), the cooling water flows in the vicinity of the exhaust port 322 (332). Thereby, there exists an advantage by which the periphery of the exhaust port 322 (332) which tends to become high temperature is cooled effectively.

  As described above, the internal combustion engine according to the present invention is useful in that the partition wall between adjacent cylinder bores can be effectively cooled.

1 is a configuration diagram illustrating an internal combustion engine according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line AA showing the internal combustion engine described in FIG. 1. FIG. 2 is a cross-sectional view taken along the line BB showing the internal combustion engine shown in FIG. It is a block diagram which shows the modification of the internal combustion engine described in FIG. It is a conceptual diagram which shows the cooling water channel | path by the side of the combustion chamber of the internal combustion engine described in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Cylinder block 21, 22 Cylinder 211, 221 Cylinder bore 23 Water jacket 24 Cooling water passage 3 Cylinder head 31 Combustion chamber 321, 331 Intake port 322, 332 Exhaust port 4 Valve system 5 Piston 41 Intake valve 42 Exhaust valve 43 Intake side intermediate mechanism 44 Exhaust side intermediate mechanism 441 Rocker arm 442 Rush adjuster 45 Camshaft

Claims (6)

An internal combustion engine including a cylinder having a cylinder bore for accommodating a piston, an intake port and an exhaust port connected to the cylinder bore, and at least a pair of the cylinders in series;
When a straight line connecting the centers of a pair of adjacent cylinder bores (hereinafter referred to as a bore center axis) 1 is drawn in a cross-sectional view perpendicular to the center axis of the cylinder bore, the cylinder bore is connected to at least one of the cylinder bores. The internal combustion engine, wherein the intake port is located on the bore center shaft l and on a partition side between the pair of cylinder bores with respect to the center of the cylinder bore. An internal combustion engine including a cylinder having a cylinder bore for accommodating a piston, an intake port and an exhaust port connected to the cylinder bore, and at least a pair of the cylinders in series;
In a cross-sectional view perpendicular to the center axis of the cylinder bore, a straight line (hereinafter referred to as a bore center axis) l connecting the centers of a pair of adjacent cylinder bores is drawn and the bore center axis l and the pair of cylinder bores are drawn. An internal combustion engine characterized in that, when an intersection P with a partition wall is taken, the intake port connected to at least one of the cylinder bores is located closer to the intersection P than the exhaust port connected to the cylinder bore.   Of the pair of adjacent cylinder bores, the intake port connected to one of the cylinder bores and the intake port connected to the other cylinder bore are in a cross-sectional view perpendicular to the central axis of the cylinder bore, The internal combustion engine according to claim 1, wherein the internal combustion engine is disposed with a partition wall between the pair of cylinder bores interposed therebetween.   A pair of the intake ports are connected to one cylinder bore, and these intake ports are arranged on the bore center shaft 1 in a cross-sectional view perpendicular to the central axis of the cylinder bore. The internal combustion engine as described in any one of 1-3.   A pair of the exhaust ports are connected to one cylinder bore, the exhaust ports and the pair of intake ports are alternately arranged around the center axis of the cylinder bore, and one of the exhaust ports The internal combustion engine according to claim 4, wherein the engine is displaced with respect to the other exhaust port in the axial direction of the bore center shaft l.   The cooling water passage is formed in the outer periphery of the arranged cylinder group, and the exhaust port is arranged on the cooling water passage side with respect to the intake port. Internal combustion engine.

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