JP2015040478A - Cylinder head for vehicular engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylinder head for a vehicular engine, in which an oil degradation is prevented, and in which the oil discharge from a cam chamber to an oil return passage is improved while improving the degree of freedom for the layout.SOLUTION: A combustion chamber side water jacket part 14 is formed over a combustion engine 6, whereas a discharge side water jacket part 15 is formed upward of an exhaust gas aggregate part 11 from the combustion chamber side water jacket part 14, and a cam chamber 20 is formed on the upper side over those jacket parts. On the lower face of the cam chamber 20, there is formed a bulging part 22 which is so inclined that a central part may be over the two end parts of the cylinder row direction and that the upper part of the discharge aggregate part 11 may be over the upper part of the combustion chamber 6. On the outer edge part of the bulging part 22, e.g., the lower face of the cam chamber 20 positioned on the two end parts of the cylinder row direction at the outer edge part, there is formed an inlet part 23 of an oil return passage 21. The oil having scattered at the upper part of the exhaust gas aggregate part 11 does not reside but flows along the inclination of the bulging part 22 to the outer edge part of the bulging part 22 so that the oil returns from the inlet part 23 of the oil return passageway 21 to an oil pan 4.

Description

  The present invention relates to a cylinder head for a vehicle engine, and is suitable, for example, for a cylinder head of a vehicle engine in which an exhaust collection portion that collects exhaust ports is integrally formed.

  As a cylinder head of such a vehicle engine, for example, there is one described in Patent Document 1 below. In the cylinder head of this vehicle engine, an exhaust collecting portion that collects exhaust ports is integrally formed, and a water jacket for cooling each exhaust port and exhaust gas in the exhaust port is formed above the exhaust port. To do. On the other hand, a cam chamber in which the camshaft is arranged is formed above the water jacket, and an oil return passage for returning the oil in the cam chamber to the oil pan is formed between the exhaust port and the exhaust port. Yes.

JP 2010-223204 A

  However, in the cylinder head of the vehicle engine described in Patent Document 1, since the oil return passage is formed between the exhaust ports, the wall portion between the oil return passage and the exhaust port, as well as the exhaust port and the exhaust port. The wall between them becomes thinner. As a result, the heat of the exhaust port leaks from the surrounding thin wall portion and is transmitted to the cam chamber above the water jacket, and the oil in the cam chamber may be deteriorated by heat. Further, if the oil in the cam chamber stays above the exhaust port and the exhaust collecting portion, the oil is heated by the heat of the exhaust port and the exhaust collecting portion, and there is a risk that the oil will deteriorate. Further, since the oil return passage is arranged between the exhaust port and the exhaust port, a space for arranging the oil return passage is required in the wall portion between the exhaust ports, and the wall portion between the exhaust ports protrudes greatly downstream in the exhaust direction. There is a need. Therefore, it is necessary to lengthen the exhaust port and the exhaust collecting portion in the exhaust direction, generally in the short side direction of the cylinder head, which may increase the size of the cylinder head and reduce the degree of freedom in design.

  The present invention has been made paying attention to the above-described problems, and improves the oil drainability from the cam chamber to the oil return passage while preventing the deterioration of the oil while increasing the degree of design freedom. It is an object of the present invention to provide a cylinder head for a vehicle engine capable of achieving the above.

  According to a first aspect of the present invention, a plurality of combustion chambers mounted above a cylinder block and disposed along a cylinder row direction, exhaust ports communicating with the respective combustion chambers, and exhaust gas in which the exhaust ports are gathered A cylinder head of a vehicle engine in which a collecting portion is integrally formed, a combustion chamber side water jacket portion formed in the upper periphery of the combustion chamber, and at least the exhaust set from the combustion chamber side water jacket portion An exhaust-side water jacket portion formed toward the upper periphery of the combustion chamber, a cam chamber formed above the combustion chamber-side water jacket portion and the exhaust-side water jacket portion, in which a camshaft is disposed, and the cam chamber Is formed on the lower surface of the cylinder, and is inclined so that a central portion in the cylinder row direction is above the both ends in the cylinder row direction, and the exhaust collecting portion is located above the combustion chamber. An bulging portion that inclines so that the upper portion is upward, and an inlet of an oil return passage that is formed on the lower surface of the cam chamber located at the outer edge of the bulging portion and returns the oil in the cam chamber to the oil pan. And a section.

  In the second aspect of the present invention, it is preferable that the inlet portion is formed at both ends of the cylinder row direction in the lower surface of the cam chamber located at the outer edge portion of the bulging portion.

  As described above, according to the first aspect, the combustion chamber, the exhaust port, and the exhaust collecting portion are integrally formed in the cylinder head attached above the cylinder block. In this cylinder head, a combustion chamber-side water jacket portion is formed in the upper periphery of the combustion chamber, and an exhaust-side water jacket portion is formed from the combustion chamber-side water jacket portion toward the upper periphery of the exhaust collecting portion. A cam chamber is formed above the water jacket portion and the exhaust water jacket portion. A bulging portion is formed on the lower surface of the cam chamber so as to incline so that the center portion in the cylinder row direction is above the both ends in the cylinder row direction and so that the upper portion of the exhaust collecting portion is above the upper portion of the combustion chamber. Form. Furthermore, an inlet portion of an oil return passage for returning the oil in the cam chamber to the oil pan is formed on the lower surface of the cam chamber located at the outer edge portion of the bulging portion. Therefore, the oil scattered by the camshaft on the upper part of the exhaust collecting part in the cam chamber flows to the outer edge part of the bulging part along the inclination of the bulging part without staying in the upper part of the exhaust collecting part, It returns to the oil pan from the entrance of the passage, and the oil dischargeability in the cam chamber is enhanced. On the lower surface of the cam chamber, the temperature at the upper part of the exhaust collecting part is most likely to be the highest. However, as described above, the oil scattered on the upper part of the exhaust collecting part flows without staying at the upper part of the exhaust collecting part. Oil deterioration due to heat is suppressed. Further, since the upper portion of the exhaust collecting portion is located at the uppermost position in the bulging portion, the lower surface of the cam chamber located at the upper portion of the exhaust collecting portion can be moved away from the exhaust collecting portion, and the cam chamber and the exhaust gas are correspondingly increased. The exhaust water jacket portion between the collecting portions can be enlarged. Accordingly, it is possible to lower the temperature of the lower surface of the cam chamber that is originally located at the upper portion of the exhaust collecting portion where the temperature is highest, and this can also suppress the deterioration of the oil scattered on the upper portion of the exhaust collecting portion. . By these, it becomes possible to prevent deterioration of oil. In addition, since it is not necessary to form an oil return passage between the exhaust ports, there is no need to lengthen the wall between the exhaust ports downstream in the exhaust direction, thereby avoiding an increase in the size of the cylinder head and increasing design flexibility. Can be increased.

  Further, according to the second aspect, the inlet portion of the oil return passage is formed at both end portions in the cylinder row direction in the lower surface of the cam chamber located at the outer edge portion of the bulging portion. Thereby, when the vehicle engine is mounted so that the exhaust collecting portion side of the cylinder head is tilted forward, the oil existing on the lower surface of the cam chamber can be efficiently and quickly returned to the oil pan from the oil return passage.

FIG. 1 is a plan view showing an embodiment of a vehicle engine to which a cylinder head of the present invention is applied. FIG. 2 is a front view of the vehicle engine of FIG. 3 is a cross-sectional view taken along the line AA in FIG. 4 is a cross-sectional view taken along the line DD of FIG. 5 is a cross-sectional view taken along the line BB in FIG. 6 is a cross-sectional view taken along the line CC of FIG. 7 is a cross-sectional view taken along line EE in FIG. FIG. 8 is an explanatory diagram in which the exhaust port and the exhaust collecting portion are superimposed on FIG.

  Next, an embodiment of a cylinder head of a vehicle engine according to the present invention will be described with reference to the drawings. FIG. 1 is a plan view of the vehicle engine of the present embodiment, and FIG. 2 is a front view of the vehicle engine of FIG. In the vehicle engine of this embodiment, a cylinder head 2 is attached to the upper end surface of the cylinder block 1, and a cylinder head cover 3 is attached to the upper end surface of the cylinder head 2. However, FIG. 1 shows a state in which the cylinder head cover is removed. A crankcase is formed at the lower part of the cylinder block 1, and the crankshaft 5 is rotatably housed in the crankcase. An oil pan 4 is attached to the lower end surface of the cylinder block 1. For example, a transmission (not shown) is attached to the vehicle engine on the right side of FIG. Although the engine body is mounted on the vehicle in various directions, in this embodiment, an oil pan 4 is attached to the opposite side of the cylinder head 2 with the cylinder block 1 interposed therebetween. In such an engine body, as described later, since the oil in the cylinder head 2 needs to be dropped onto the oil pan 4 by gravity, the cylinder head 2 is mounted so as to be approximately upward with respect to the cylinder block 1. For this reason, the direction of the cylinder head 2 with respect to the cylinder block 1 is defined as upward and the reverse direction is defined as downward. Further, the engine body of the present embodiment is arranged so that an exhaust collecting portion side described later is inclined forward.

  In the cylinder block 1, a plurality of cylinders (cylinder bores) (not shown) in the present embodiment are formed along the cylinder row. A combustion chamber 6 is formed at each cylinder head 2 side end of each cylinder. That is, in this embodiment, three combustion chambers 6 are formed along the cylinder row. Therefore, the axis of the crankshaft 5 is parallel to the arrangement direction of the combustion chambers 6, that is, the cylinder rows. A piston (not shown) is accommodated in each cylinder, and each piston is connected to a crankpin of the crankshaft 5 by a connecting rod (connecting rod) (not shown). Further, for example, as shown in FIG. 6, each combustion chamber 6 has an intake port 7 for sucking an air-fuel mixture into the combustion chamber 6 and an exhaust port 8 for exhausting exhaust gas from the combustion chamber 6. Connected. Each combustion chamber 6 is also connected with a spark plug mounting hole 9 for mounting a spark plug (not shown) and a fuel injection device mounting hole 10 for mounting a fuel injection device (not shown). Is also formed in the cylinder head 2. The intake port 7 is opened and closed by an unillustrated intake valve, and the exhaust port 8 is opened and closed by an unillustrated exhaust valve.

  Therefore, the air-fuel mixture is combusted when the air-fuel mixture is sucked into each cylinder from the intake port 7 by opening the intake valve, the air-fuel mixture is compressed by the piston while the intake valve is closed, and the compressed air-fuel mixture is ignited.・ The piston expands and is pushed down in each cylinder. Since the crank pin to which the piston is connected by the connecting rod is eccentric with respect to the rotation axis of the crank shaft 5, the linear movement of the piston is converted into the rotation movement of the crank shaft 5. The rotational movement of the crankshaft 5 is shifted in the transmission and transmitted as driving force to driving wheels (not shown). Further, the exhaust gas generated by the combustion of the air-fuel mixture is exhausted to one end in the direction intersecting the cylinder row direction of the cylinder head 2 through the exhaust port 8 in which the exhaust valve is opened, that is, the front side in this embodiment. Is done.

  3 is a sectional view taken along the line AA in FIG. 1, FIG. 4 is a sectional view taken along the line DD in FIG. 2, FIG. 5 is a sectional view taken along the line BB in FIG. 7 is an EE cross-sectional view of FIG. 2, and FIG. 8 is an explanatory view in which the exhaust port and the exhaust collecting portion are superimposed on FIG. In this embodiment, the exhaust ports 8 are gathered in the cylinder head 2 to form an exhaust gathering portion 11, whereby the exhaust manifold 12 is formed integrally with the cylinder head 2. Since the exhaust collecting portion 11, the exhaust port 8, and the combustion chamber 6 become high temperature, a water jacket 13 for cooling them with cooling water is formed inside the cylinder head 2. The water jacket 13 is formed on the combustion chamber side water jacket portion 14 formed in the upper periphery of the combustion chamber 6, and from the combustion chamber side water jacket portion 14 to the upper periphery of the exhaust collecting portion 11 through the upper periphery of the exhaust port 8. An exhaust-side water jacket portion 15 formed so as to face is configured. That is, the exhaust side water jacket portion 15 is formed from the combustion chamber side water jacket portion 14 toward at least the upper periphery of the exhaust collecting portion 11. Further, the exhaust-side water jacket portion 15 of the present embodiment includes a lower water jacket portion 16 formed from the combustion chamber-side water jacket portion 14 toward the lower periphery of the exhaust collecting portion 11 through the lower periphery of the exhaust port 8. I have. In the present embodiment, for example, cooling water is passed through the water jacket 13 from the right side of FIG. 7 and drained from the left side of the drawing, so Cool the exhaust gas.

  The intake valve described above is driven by the intake side camshaft 17, and the exhaust valve is driven by the exhaust side camshaft 18. The intake side camshaft 17 and the exhaust side camshaft 18 are connected to the crankshaft 5 by a chain (not shown) in the chain case 19 and rotate in synchronization with the crankshaft 5. The intake side camshaft 17 and the exhaust side camshaft 18 are arranged in a cam chamber 20 formed in the cylinder head 2 above the water jacket 13. The intake side camshaft 17 and the exhaust side camshaft 18 are lubricated with oil supplied from an oil pump (not shown) driven by the crankshaft 5. Oil that has lubricated the intake camshaft 17 and the exhaust camshaft 18 scatters into the cam chamber 20, but is returned to the oil pan 4 through the oil return passage 21 formed in the cylinder head 2 and the cylinder block 1.

  In the present embodiment, a portion corresponding to the upper surface of the exhaust water jacket portion 15 in the lower surface of the cam chamber 20 is expanded upward to form the bulging portion 22. That is, the lower part of the bulging part 22 is the exhaust side water jacket part 15. For example, as shown in FIGS. 3 and 5, the bulging portion 22 is inclined so that the central portion in the cylinder row direction is located above both ends in the cylinder row direction, and the combustion is performed as shown in FIG. 6, for example. The upper part of the exhaust collecting part 11 is inclined from the upper part of the chamber 6 so as to be upward. That is, the bulging portion 22 is inclined so that the portion located at the upper portion of the exhaust collecting portion 11 is located at the uppermost position, and descends from there toward the combustion chamber 6 side and both ends in the cylinder row direction. Therefore, the oil scattered on the upper surface of the bulging portion 22 is directed toward the outer edge portion of the bulging portion 22 along the inclination of the bulging portion 22 as shown by white arrows in FIGS. Flowing. Therefore, in the present embodiment, the inlet portion 23 of the oil return passage 21 described above is formed at the outer edge portion of the bulging portion 22. More specifically, the inlet portion 23 of the oil return passage 21 is formed at both ends in the cylinder row direction in the outer edge portion of the bulging portion 22. The oil that flows along the inclination of the bulging portion 22 flows into the oil return passage 21 from the inlet portion 23 formed at the outer edge portion of the bulging portion 22 and returns to the oil pan 4. In the case of the present embodiment, as described above, the engine main body is arranged so that the exhaust collecting portion 11 side is inclined forward, so that both ends of the bulging portion 22 are at the lowest position in the cylinder row direction. . Therefore, by forming the inlet portions 23 at both ends in the cylinder row direction in the outer edge portion of the bulging portion 22, the oil can be more easily poured into the oil return passage 21. In the present embodiment, the inlet 23 is also formed on the chain case 19 side of the lower surface of the cam chamber 20. This is because the oil that has flowed into the chain case 19 from the inlet 23 passes through the chain case 19 and returns to the oil pan 4.

  Here, as in Patent Document 1, if an oil return passage is to be formed between exhaust ports, a region through which the oil return passage passes is required between the exhaust port and the exhaust port. For example, when an oil return passage is formed between the exhaust port 8 and the exhaust port 8 shown in FIG. 7, it is necessary to secure a cross-sectional area of a portion where adjacent exhaust ports 8 merge. The wall part of the merge part becomes large. Specifically, the wall portion of the exhaust port 8 merging portion becomes longer toward the downstream side in the exhaust direction, and the cylinder head 2 becomes longer in the direction intersecting the cylinder row direction. And the degree of design freedom is limited. On the other hand, in this embodiment, since it is not necessary to form the oil return passage 21 between the exhaust ports 8, an increase in the size of the cylinder head 2 can be avoided and the degree of design freedom can be increased.

  As described above, in the cylinder head of the vehicle engine according to the present embodiment, the combustion chamber 6, the exhaust port 8, and the exhaust collecting portion 11 are integrally formed in the cylinder head 2 attached above the cylinder block 1. In this cylinder head 2, a combustion chamber-side water jacket portion 14 is formed in the upper periphery of the combustion chamber 6, and the exhaust-side water jacket portion 15 is directed from the combustion chamber-side water jacket portion 14 toward the upper periphery of the exhaust collecting portion 11. The cam chamber 20 is formed above the combustion chamber side water jacket portion 14 and the exhaust side water jacket portion 15. The cam chamber 20 is inflated on the lower surface so that the central portion in the cylinder row direction is above the both ends in the cylinder row direction and the upper portion of the exhaust collecting portion 11 is above the upper portion of the combustion chamber 6. A protruding portion 22 is formed. Further, an inlet portion 23 of an oil return passage 21 for returning the oil in the cam chamber 20 to the oil pan 4 is formed on the lower surface of the cam chamber 20 located at the outer edge portion of the bulging portion 22. Therefore, the oil scattered on the upper portion of the exhaust collecting portion 11 in the cam chamber 20 by the camshafts 17 and 18 does not stay on the upper portion of the exhaust collecting portion 11, and is swelled along the inclination of the bulging portion 22. The oil flows into the outer edge portion 22 and returns to the oil pan 4 from the inlet portion 23 of the oil return passage 21, so that the oil dischargeability in the cam chamber 20 is enhanced. Further, on the lower surface in the cam chamber 20, the temperature of the upper part of the exhaust collecting part 11 is most likely to be highest. However, as described above, the oil scattered on the upper part of the exhaust collecting part 11 stays in the upper part of the exhaust collecting part 11. Therefore, oil deterioration due to heat is suppressed. Further, since the upper portion of the exhaust collecting portion 11 is located at the uppermost position in the bulging portion 22, the lower surface of the cam chamber 20 located on the upper portion of the exhaust collecting portion 11 can be moved away from the exhaust collecting portion 11. The exhaust-side water jacket portion 15 between the cam chamber 20 and the exhaust collecting portion 11 can be enlarged. Therefore, the temperature of the lower surface of the cam chamber 20 positioned at the upper portion of the exhaust collecting portion 11 where the temperature becomes highest can be lowered, and this also suppresses the deterioration of the oil scattered on the upper portion of the exhaust collecting portion 11. be able to. By these, it becomes possible to prevent deterioration of oil. Further, since it is not necessary to form the oil return passage 21 between the exhaust ports 8, it is not necessary to lengthen the wall portion between the exhaust ports 8 on the downstream side in the exhaust direction, thereby avoiding an increase in the size of the cylinder head 2. Design freedom can be increased.

  Further, the inlet portions 23 of the oil return passages 21 are formed at both ends in the cylinder row direction on the lower surface of the cam chamber 20 located at the outer edge portion of the bulging portion 22. Thereby, when the vehicle engine is mounted so that the exhaust collecting portion 11 side of the cylinder head 2 tilts forward, the oil existing on the lower surface of the cam chamber 20 is efficiently and quickly transferred from the oil return passage 21 to the oil pan 4. Can be returned.

  Although the embodiments of the present invention have been disclosed above, it will be apparent to those skilled in the art that changes can be made without departing from the scope of the present invention. All such modifications and equivalents are intended to be included in the following claims.

DESCRIPTION OF SYMBOLS 1 Cylinder block 2 Cylinder head 3 Cylinder head cover 4 Oil pan 5 Crankshaft 6 Combustion chamber 7 Intake port 8 Exhaust port 9 Spark plug mounting hole 10 Fuel injection device mounting hole 11 Exhaust collecting part 12 Exhaust manifold 13 Water jacket 14 Combustion chamber side water Jacket portion 15 Exhaust water jacket portion 16 Lower water jacket portion 17 Intake side camshaft 18 Exhaust side camshaft 19 Chain case 20 Cam chamber 21 Oil return passage 22 Swelling portion 23 Inlet portion

Claims (2)

A plurality of combustion chambers mounted above the cylinder block and arranged along the cylinder row direction, an exhaust port communicating with each combustion chamber, and an exhaust collecting portion where the exhaust ports gather are integrally formed. A cylinder head of a vehicle engine,
A combustion chamber-side water jacket portion formed in the upper periphery of the combustion chamber;
An exhaust-side water jacket portion formed from the combustion chamber-side water jacket portion toward at least the upper periphery of the exhaust collecting portion;
A cam chamber formed above the combustion chamber-side water jacket portion and the exhaust-side water jacket portion, in which a camshaft is disposed;
It is formed on the lower surface of the cam chamber, and is inclined so that the central portion in the cylinder row direction is upward from both ends in the cylinder row direction, and is inclined so that the upper portion of the exhaust collecting portion is upward from the upper portion of the combustion chamber. A bulge that
An engine for a vehicle, comprising: an inlet portion of an oil return passage formed on a lower surface of the cam chamber located at an outer edge portion of the bulge portion and returning oil in the cam chamber to an oil pan. cylinder head.   2. The cylinder head for a vehicular engine according to claim 1, wherein the inlet portion is formed at both ends in the cylinder row direction in a lower surface of the cam chamber located at an outer edge portion of the bulging portion.

Images