JP2006083756A - Structure of cylinder head in multi-cylinder internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To arrange collection exhaust ports with respect to a plurality of cylinders in such form that avoids interference with exhaust gas in their inside securely when forming the collection exhaust ports inside a cylinder head in a multi-cylinder internal combustion engine constructed by arranging four cylinders in a row. <P>SOLUTION: The first collection exhaust port 16 in which exhaust ports in the first cylinder A1 and the fourth cylinder A4 among four cylinders A1, A2, A3, A4 are collected is formed to extend in the direction of row of each cylinder. The second collection exhaust port 17 in which exhaust ports in the second cylinder A2 and the third cylinder A3 among four cylinders A1, A2, A3, A4 are collected is formed to extend by crossing the first collection exhaust port three-dimensionally. An exhaust gas outlet 19 communicating with the first collection exhaust port and an exhaust gas outlet 20 communicating with the second collection exhaust port are opened separately or are opened in one on a side face 18 of the cylinder head 4. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a structure of a cylinder head formed in a multi-cylinder internal combustion engine having four cylinders, in which exhaust ports (exhaust passages) in the respective cylinders are aggregated.

  In a recent multi-cylinder internal combustion engine, for the purpose of promoting the purification of exhaust gas at the start of the internal combustion engine and reducing the size of the internal combustion engine, the cylinder head is provided with each cylinder. The exhaust ports (exhaust passages) are formed in a collective form for a plurality of cylinders.

  That is, in Patent Document 1, in an internal combustion engine having four cylinders, a single collective exhaust port (collective exhaust passage) that collects exhaust ports in the cylinders is provided in the cylinder head. It is described that the exhaust gas outlet in the collective exhaust port is opened to the side surface of the cylinder head.

  Further, in Patent Document 2, in an internal combustion engine having four cylinders, a first set in which exhaust ports of the first and second cylinders adjacent to each other among the four cylinders are gathered inside the cylinder head. An exhaust port (first collective exhaust passage) and a second collective exhaust port (second collective exhaust passage) that collects exhaust ports of the third and fourth cylinders adjacent to each other among the four cylinders are formed. , It is described that the exhaust gas outlets in both the collective exhaust ports are configured to open to the side surfaces of the cylinder head.

Furthermore, in Patent Documents 3 and 4, in an internal combustion engine having six cylinders, exhausts in the first, second, and third cylinders adjacent to each other among the six cylinders are disposed inside the cylinder head. A first collective exhaust port (first collective exhaust passage) that collects the ports, and a second collective exhaust that collects exhaust ports in the remaining fourth, fifth, and sixth cylinders among the six cylinders It is described that a port (second collective exhaust passage) is formed and exhaust gas outlets in both the collective exhaust ports are opened to the side surface of the cylinder head.
Japanese Utility Model Publication No. 51-13981 Japanese Patent Laid-Open No. 51-120337 JP-A-1-182560 JP 2000-265903 A

  However, in a four-cylinder internal combustion engine, as is well known in the art, the order of ignition in each cylinder is determined in order to balance the rotation of the crankshaft. The third cylinder is set, or the first cylinder, the third cylinder, the fourth cylinder, and the second cylinder are set.

  In the four-cylinder internal combustion engine having such an ignition sequence, as described in Patent Document 1, the exhaust ports in each cylinder are assembled into one collective exhaust port, or the first cylinder and the adjacent cylinders When the exhaust ports in the second cylinder are gathered in the first collective exhaust port and the exhaust ports in the adjacent third and fourth cylinders are gathered in the second collective exhaust port, the ignition of each cylinder is ignited. Exhaust gases from two cylinders that are adjacent to each other interfere with each other in the one collective exhaust port and the first and second collective exhaust ports. There was a problem of inviting a decline.

  In the case of Patent Documents 3 and 4, exhaust gases from two cylinders whose ignition sequences are adjacent to each other interfere with each other when they merge into the first and second collective exhaust ports. There has been a problem that the exhaust efficiency of exhaust gas is reduced, and as a result, the output is reduced.

  An object of the present invention is to provide a structure of a cylinder head that does not cause such a problem.

In order to achieve this technical problem, claim 1 of the present invention provides:
“In a four-cycle multi-cylinder internal combustion engine in which four cylinders are arranged in a row, a first cylinder and a fourth cylinder located at both ends of the four cylinders in the row direction are disposed inside the cylinder head. A first collective exhaust port in which exhaust ports in the cylinder are gathered so as to extend in the row direction of the cylinders, and a second one of the four cylinders located between the first cylinder and the fourth cylinder. A second collective exhaust port in which exhaust ports in the cylinder and the third cylinder gather is formed so as to extend three-dimensionally intersecting the first collective exhaust port, and communicated with the first collective exhaust port on a side surface of the cylinder head The exhaust gas outlets to be opened and the exhaust gas outlets communicating with the second collective exhaust port are opened separately or as one.
It is characterized by that.

Claim 2 of the present invention includes:
“In the first aspect of the present invention, the second collective exhaust port is configured to cross three-dimensionally below the first collective exhaust port.”
It is characterized by that.

Claim 3 of the present invention provides:
“In the description of claim 2, when the second collective exhaust port is viewed from the column direction of each cylinder, the exhaust gas outlet at the second collective exhaust port is lower than the middle part of the second collective exhaust port. Curved upwardly convex so as to be located at the site. "
It is characterized by that.

Claim 4 of the present invention provides:
“In any one of claims 1 to 3, an exhaust gas outlet in the first collective exhaust port and an exhaust gas outlet in the second collective exhaust port are arranged in the second direction in the column direction of each cylinder. The cylinders are opened in two upper and lower stages at a position intermediate between the cylinder and the third cylinder. "
It is characterized by that.

According to a fifth aspect of the present invention, in the first aspect, the second collective exhaust port is configured to form a three-dimensional intersection with the upper side of the first collective exhaust port. While the exhaust gas outlet and the exhaust gas outlet at the second collective exhaust port are opened in two upper and lower stages at an intermediate position between the second cylinder and the third cylinder in the row direction of the cylinder, the cylinder On the side surface of the head, a downwardly curved or bent first elbow exhaust pipe communicating with the exhaust gas outlet in the first collective exhaust port, and downward curved communicating with the exhaust gas outlet in the second collective exhaust port The second elbow exhaust pipe is connected to the second elbow exhaust pipe, and the second elbow exhaust pipe of the two elbow exhaust pipes is directed downward on the outside of the downward curve or bend in the first elbow exhaust pipe. To tune or bent. "
It is characterized by that.

Claim 6 of the present invention provides:
“In any one of claims 1 to 5, an exhaust gas outlet in the first collective exhaust port and an exhaust gas outlet in the second collective exhaust port that open to a side surface of the cylinder head are arranged in the row of the cylinders. Make it horizontally long in the direction. "
It is characterized by that.

Claim 7 of the present invention provides:
“In the description of any one of claims 4 to 6, the portions of the first collective exhaust port on both sides of the exhaust gas outlet opening on the cylinder head side face toward the exhaust gas outlet in plan view. And tilt outward. "
It is characterized by that.

  As described above, the ignition sequence in the four-cycle four-cylinder internal combustion engine is first cylinder-second cylinder-fourth cylinder-third cylinder, or first cylinder-third cylinder-fourth cylinder- By being the second cylinder, the exhaust gas from the first cylinder and the fourth cylinder among the four cylinders is discharged through the first collective exhaust port extending in the column direction of the cylinders, while the four cylinders Of these, the exhaust gas from the second cylinder and the third cylinder is exhausted through a second collective exhaust port extending so as to form a three-dimensional intersection with the first collective exhaust port.

  The exhaust stroke in the first cylinder and the exhaust stroke in the fourth cylinder are 360 degrees in crank angle such that the exhaust stroke in the second cylinder or the exhaust stroke in the third cylinder exists between them. By shifting, it is possible to reliably avoid the exhaust gas from the first cylinder and the exhaust gas from the fourth cylinder from interfering with each other in the first collective exhaust port.

  Also, the exhaust stroke in the second cylinder and the exhaust stroke in the third cylinder are determined by the crank angle such that the exhaust stroke in the first cylinder or the exhaust stroke in the fourth cylinder exists between them. By shifting 360 degrees, the exhaust gas from the second cylinder and the exhaust gas from the third cylinder can be prevented from interfering with each other in the second collective exhaust port.

  In other words, according to the first aspect of the present invention, when the collective exhaust port for a plurality of cylinders is formed inside the cylinder head, the collective exhaust port is used to ensure interference of exhaust gas in the collective exhaust port. Therefore, it is possible to improve the exhaust performance of the exhaust gas while maintaining the merit of forming the collective exhaust port inside the cylinder head, thereby improving the output in the internal combustion engine. Can be achieved.

  By the way, in a four-cylinder internal combustion engine, it is very common to configure an overhead such as providing a valve operating mechanism for opening and closing an intake valve and an exhaust valve on the upper surface of the cylinder head. The temperature of exhaust gas from the second cylinder and the third cylinder located between the first cylinder and the fourth cylinder among the cylinders is higher than the temperature of exhaust gas from the first cylinder and the fourth cylinder on both sides thereof. Therefore, the temperature in the second collective exhaust port that collects the exhaust ports of the second and third cylinders is the first collective exhaust port that collects the exhaust ports of the first and fourth cylinders. It tends to be higher than the temperature at.

  Therefore, as described in claim 2, by configuring the second collective exhaust port so that the lower side of the first collective exhaust port is three-dimensionally crossed, the temperature of both the collective exhaust ports tends to increase. The second collective exhaust port can be moved away from the valve mechanism for the exhaust valve among the valve mechanisms on the upper surface of the cylinder head, and the bend in the second collective exhaust port causes the second collective exhaust port to be This is less than the case where the upper side of the first collective exhaust port is three-dimensionally crossed, so that the heat damage to the exhaust valve operating mechanism can be reduced.

  In this case, as described in claim 3, in addition to configuring the second collective exhaust port as in claim 2, the second collective exhaust port as viewed from the column direction of each cylinder. The exhaust gas outlet in the cylinder is curved upward and convex so that the exhaust gas outlet is located at a position lower than the middle portion of the second collective exhaust port, thereby making the second collective exhaust port an exhaust valve valve on the upper surface of the cylinder head. Since the exhaust gas outlet at the second collective exhaust port can be further moved away from the mechanism, the heat damage to the valve mechanism for the exhaust valve can be further reduced, and the two collective exhausts of the cylinder head can be further reduced. Since the height dimension in the portion forming the port can be lowered by the amount that the exhaust gas outlet in the second collective exhaust port is lowered, Further be achieved bets and weight.

  Next, as described in claim 4, an exhaust gas outlet in the first collective exhaust port and an exhaust gas outlet in the second collective exhaust port are connected to the second cylinder in the row direction of the cylinders. By opening in two upper and lower stages at an intermediate position with respect to the third cylinder, the passage length from the first cylinder to the exhaust gas outlet of the first collective exhaust port and the distance from the fourth cylinder to the exhaust gas outlet are arranged. While the passage length is substantially the same, the passage length from the second cylinder to the exhaust gas outlet in the second collective exhaust port is substantially the same as the passage length from the third cylinder to the exhaust gas outlet. In addition to avoiding non-uniform exhaust gas discharge between the first cylinder and the fourth cylinder and between the second cylinder and the third cylinder, the exhaust efficiency can be improved. , Both collective exhaust ports It is possible to connect exhaust pipes for guiding exhaust gas to an exhaust gas purifier or an exhaust turbocharger, or exhaust system parts such as an exhaust gas purifier or an exhaust turbocharger, at both exhaust gas outlets Since the exhaust system parts can be connected to the flange side of the cylinder head at the same time, the connection structure and labor of the exhaust system pipe line can be simplified.

  However, in the case of the configuration according to claim 4, the exhaust from the exhaust port of each cylinder to the side surface of the cylinder head in the second collective exhaust port is between the first collective exhaust port and the second collective exhaust port. There is a difference in the passage length such that the passage to the gas outlet is considerably shorter than the passage from the exhaust port of each cylinder to the exhaust gas outlet to the side of the cylinder head in the first collective exhaust port. Therefore, the exhaust gas is unevenly discharged between the first collective exhaust port and the second collective exhaust port, resulting in a decrease in exhaust efficiency.

  Accordingly, in the case of an internal combustion engine mounted on a vehicle, a flange is formed on the side surface of the cylinder head in order to dispose a path for releasing the exhaust gas to the atmosphere on the lower surface of the floor of the vehicle. Focusing on the fact that it is very common that the exhaust pipe to be joined is an elbow exhaust pipe curved or bent downward, the second collective exhaust port is defined as the first collective exhaust port. The exhaust gas outlet at the first collective exhaust port and the exhaust gas outlet at the second collective exhaust port are connected to the second cylinder in the row direction of the cylinders. The first cylinder is opened in two upper and lower stages at an intermediate position with respect to the third cylinder, and is curved or bent downward on the side surface of the cylinder head so as to communicate with the exhaust gas outlet of the first collective exhaust port. A second elbow exhaust pipe that curves downward and communicates with an exhaust gas outlet in the second collective exhaust port, and the second elbow exhaust pipe of both elbow exhaust pipes is connected to the second elbow exhaust pipe, The first elbow exhaust pipe is configured to be bent or bent downward on the outside of the downward curve or bend.

  With this configuration, the passage length from the exhaust port of each cylinder to the outlet of the second elbow exhaust pipe in the second collective exhaust port is such that the second collective exhaust port is located above the first collective exhaust port. The second elbow exhaust pipe is lengthened by the amount of bending or bending downward in the downward direction of the first elbow exhaust pipe. Since the passage length in the two collective exhaust ports and the second elbow exhaust pipe approaches the passage length in the first collective exhaust port and the first elbow exhaust pipe, the difference in the passage length between them becomes small. The non-uniformity of exhaust gas discharge between the first collective exhaust port and the second collective exhaust port can be greatly improved, and a decrease in exhaust efficiency can be reliably avoided.

  Further, as described in claim 6, in any one of claims 1 to 5, the exhaust gas outlet in the first collective exhaust port that opens to the side surface of the cylinder head, and the second collective exhaust port By making the exhaust gas outlets horizontally long in the row direction of the cylinders, the heights of the portions of the cylinder head where the two exhaust ports are formed are not increased, so that both the exhaust gas outlets Sufficient passage area can be secured, in other words, the height of the portion of the cylinder head where the two exhaust ports are formed in a state where a sufficient passage area is secured at both exhaust gas outlets. Since the dimensions can be reduced, the size and weight can be reduced accordingly.

  Furthermore, as described in claim 7, in any one of claims 4 to 6, portions of both sides of the first collective exhaust port sandwiching the exhaust gas outlet opening on a side surface of the cylinder head. In plan view, the exhaust gas flowing in the direction from the first cylinder to the exhaust gas outlet in the first collective exhaust port, and the first collective exhaust port The exhaust gas flowing in the direction from the fourth cylinder to the exhaust gas outlet can be guided to the exhaust gas outlet by an outward inclination toward the exhaust gas outlet, and the exhaust gas from the first cylinder is guided to the fourth cylinder. Since the exhaust gas from the fourth cylinder can be reliably prevented from flowing in the direction of the first cylinder, the exhaust efficiency of the exhaust gas can be further improved.

  Next, embodiments of the present invention will be described with reference to the drawings.

  1 to 4 show a first embodiment.

  In the first embodiment shown in FIGS. 1 to 4, reference numeral 1 designates four cylinders A1, A2, A3, A4 having a common crankshaft (not shown) in plan view (FIG. 1). ) Shows a four-cycle type four-cylinder internal combustion engine arranged in a line along the crank axis 2.

  The internal combustion engine 1 includes a cylinder block 3 and a cylinder head 4 fastened to the upper surface of the cylinder block 3 with a plurality of head bolts (not shown), as is well known. Has been.

  On the lower surface of the cylinder head 4, a combustion chamber 5 is recessed at each of the cylinders A <b> 1, A <b> 2, A <b> 3, A <b> 4, and each of the combustion chambers 5 has two intake ports 6 and the same. Two exhaust ports 7 are opened, a fuel injection valve and a spark plug (not shown) are provided, and an intake valve 8 for opening and closing the intake ports 6 in the combustion chamber 5 is provided. Each exhaust port 7 is provided with an exhaust valve 9 for opening and closing the exhaust port 7.

  On the other hand, on the upper surface of the cylinder head 4, an intake valve valve mechanism for opening and closing the intake valve 8 in each of the cylinders A1, A2, A3, A4 according to the rotation of a crankshaft (not shown). And an exhaust valve comprising a camshaft 10 and a rocker arm 11 for opening and closing the exhaust valve 9 in each of the cylinders A1, A2, A3, A4 according to the rotation of the crankshaft (not shown). A valve operating mechanism 12 is provided, and a head cover 13 that covers the upper surface of the cylinder head 4 is detachably attached.

  In this case, the ignition sequence in the internal combustion engine 1 is set to the first cylinder A1, the second cylinder A2, the fourth cylinder A4, the third cylinder A3 in order to balance the rotation of the crankshaft. 1 cylinder A1, 3rd cylinder A3, 4th cylinder A4 and 2nd cylinder A2 are set.

  Further, among the insides of the cylinder head 4, both the cylinders A 1, A 2, A 3, and A 4 are disposed between the crank axis 2 and one longitudinal side surface 14 of the cylinder head 4 in plan view (FIG. 1). An intake port 15 that communicates with the intake port 6 and opens in the longitudinal side surface 14 is provided for each of the cylinders A1, A2, A3, and A4.

  In the inside of the cylinder head 4, one end is located on the opposite side of the intake port 15 across the crank axis 2 in plan view, and the other end is located on the exhaust port 7 in the first cylinder A 1. First collective exhaust ports (first collective exhaust passages) 16 respectively communicating with the exhaust ports 7 in the fourth cylinder A4 are formed so as to extend in the direction of the crank axis 2 in a plan view, and the second collective ports at one end thereof A second collective exhaust port (second collective exhaust passage) 17 that is substantially Y-shaped in plan view so that the exhaust port 7 in the cylinder A2 communicates with the exhaust port 7 in the third cylinder A3 is connected to the first collective exhaust. It is formed so as to cross the port 16 and extend toward the other side surface 18.

  On the other hand, the exhaust gas outlet 19 in the first collective exhaust port 16 and the second collective exhaust port are located at an intermediate position between the second cylinder A2 and the third cylinder A3 in the other side surface 18 of the cylinder head 4. 17 and the exhaust gas outlet 20 are provided so as to be opened in two stages.

  In the first embodiment, the second collective exhaust port 17 is configured such that the lower side of the first collective exhaust port 16 intersects the lower side of the first collective exhaust port 16 so that the second collective exhaust port 17 It is made to keep away from the valve operating mechanism 12 for exhaust valves.

  In this case, when the second collective exhaust port 17 is viewed from the direction of the crank axis 2, that is, the row direction of each cylinder, as shown in FIG. 3, the exhaust gas outlet 20 in the second collective exhaust port 17. Can be further away from the exhaust valve operating mechanism 12 by being configured to be curved upward and convex so as to be located at a lower position than the middle portion of the second collective exhaust port 17, The height dimension H of the cylinder head 4 at the portion where the two collective exhaust ports 16 and 17 are formed can be lowered by the amount of the exhaust gas outlet 20 at the second collective exhaust port 17 located at a low position. .

  Further, on the side surface 18 of the cylinder head 4, the exhaust gas discharged from the exhaust gas outlets 19 and 20 at both the collective exhaust ports 16 and 17 is guided to an exhaust gas purifier (not shown) or an exhaust turbocharger. The exhaust pipe 21 may be flange-connected, and an exhaust gas purifier or an exhaust turbocharger may be directly flange-connected to the side surface 18 of the cylinder head 4.

  Inside the cylinder head 4, a cooling water jacket 24 surrounds the combustion chambers 5, the first collective exhaust port 16, the second collective exhaust port 17, and the intake ports 15. Needless to say, it is formed.

  In the above-described configuration, the exhaust gas in the first cylinder A1 and the exhaust gas in the fourth cylinder A4 among the cylinders are exhausted from the exhaust ports 7 in the cylinders A1 and A4 through the first collective exhaust port 16. While being discharged from the outlet 19, the exhaust gas in the second cylinder A2 and the exhaust gas in the third cylinder A3 among the cylinders pass through the second collective exhaust port 17 from the exhaust ports 7 in the cylinders A2 and A3. It is discharged from the exhaust gas outlet 20.

  In this case, the ignition order in the four-cycle four-cylinder internal combustion engine is, as described above, the first cylinder-second cylinder-fourth cylinder-third cylinder, or the first cylinder-third cylinder-first. Due to the four-cylinder-second cylinder, the exhaust stroke in the first cylinder A1 and the exhaust stroke in the fourth cylinder A4 are between the exhaust stroke in the second cylinder A2 or the exhaust in the third cylinder A3. Since there is a shift in the crank angle of 360 degrees such that a stroke exists, the exhaust gas from the first cylinder A1 and the exhaust gas from the fourth cylinder A4 are mutually in the first collective exhaust port 16. Interference can be reliably avoided.

  On the other hand, the exhaust stroke in the second cylinder A2 and the exhaust stroke in the third cylinder A3 are such that the exhaust stroke in the first cylinder A1 or the exhaust stroke in the fourth cylinder A4 exists between them. Since the angle is shifted by 360 degrees, it is possible to prevent the exhaust gas from the second cylinder A2 and the exhaust gas from the third cylinder A3 from interfering with each other in the second collective exhaust port 17.

  The exhaust gas outlet 19 in the first collective exhaust port 16 and the exhaust gas outlet 20 in the second collective exhaust port 17 are opened separately on the side surface 18 of the cylinder head 4 or on the crank axis 2. Although it may be configured to open to portions shifted from each other along the direction, as described above, the exhaust gas outlet 19 in the first collective exhaust port 16 and the exhaust gas outlet in the second collective exhaust port 17. 20 in the first collective exhaust port 16 by opening them in two upper and lower stages at an intermediate position between the second cylinder A2 and the third cylinder A3 in the row direction of the cylinders. The length of the passage from the cylinder A1 to the exhaust gas outlet 19 and the length of the passage from the fourth cylinder A4 to the exhaust gas outlet 19 are substantially the same. Since the passage length from the second cylinder A2 to the exhaust gas outlet 20 and the passage length from the third cylinder A3 to the exhaust gas outlet 20 are substantially the same, it is between the first cylinder A1 and the fourth cylinder A4. , And the exhaust gas exhaust between the second cylinder A2 and the third cylinder A3 can be avoided, and the exhaust pipes to the exhaust gas outlets 19, 20 at the two exhaust ports 16, 17 can be avoided. The connection of the passage 21 or the exhaust gas purifier or the exhaust turbocharger can be made simultaneously by the flange connection to the side surface 18 of the cylinder head 4 of the exhaust pipe 21 or the exhaust gas purifier or the exhaust turbocharger.

  The first collective exhaust port 16 includes a portion 16a between the first cylinder A1 and the exhaust gas outlet 19 of the first collective exhaust port 16, and the fourth cylinder A4 and the exhaust gas outlet 19. As shown in FIGS. 1 and 4, the intermediate portion 16 b is configured to incline outward toward the exhaust gas outlet 19.

  With this configuration, the exhaust gas flowing in the direction from the first cylinder A1 to the exhaust gas outlet 19 flows along the inner surface of the inclined portion 16a as shown by the arrow B1 in FIG. Alternatively, the exhaust gas flowing in the direction from the fourth cylinder A4 to the exhaust gas outlet 19 is guided along the inner surface of the inclined portion 16b in FIG. As indicated by an arrow B2, the exhaust gas can be guided into the exhaust gas outlet 19 or the exhaust pipe line 21 connected thereto, so that the exhaust gas from the first cylinder A1 flows in the direction of the fourth cylinder A4. It is possible to reliably prevent the exhaust gas from the fourth cylinder A4 from flowing in the direction of the first cylinder A1. In this case, the angle θ between the arrows B1 and B2 and the inner surface is preferably set to 90 degrees or less.

  Furthermore, the exhaust gas outlet 19 with respect to the side surface 18 of the cylinder head 4 in the first collective exhaust port 16 and the exhaust gas outlet 20 with respect to the side surface 18 of the cylinder head 4 in the second collective exhaust port 17 have a circular cross section. Instead, as shown in FIG. 2, the cylinders are formed in a horizontally long shape in the row direction.

  Thus, by making both the exhaust gas outlets 19 and 20 horizontally long in the column direction of each cylinder, the height dimension H in the portion of the cylinder head 4 where the two exhaust ports 16 and 17 are formed is increased. Therefore, it is possible to ensure a sufficient passage area for both the exhaust gas outlets 19 and 20, in other words, in a state where a sufficient passage area is secured for both the exhaust gas outlets 19 and 20. The height dimension H in the portion of the cylinder head 4 where the two collective exhaust ports 16 and 17 are formed can be reduced.

  Next, FIGS. 5 and 6 show a second embodiment.

  In the second embodiment, in the four-cycle four-cylinder internal combustion engine 1, a portion of the inside of the cylinder head 4 opposite to the intake ports 15 across the crank axis 2 in plan view. In addition, a first collective exhaust port 16 ′ (first collective exhaust passage) that collects the exhaust port 7 in the first cylinder A 1 and the exhaust port 7 in the fourth cylinder A 4 is formed so as to extend in the direction of the crank axis 2. In addition, a second collective exhaust port 17 ′ (second collective exhaust passage) having a substantially Y shape so as to collect the exhaust port 7 in the second cylinder A2 and the exhaust port 7 in the third cylinder A3 is provided in the first cylinder. In forming the second collective exhaust port 17 'so as to cross the collective exhaust port 16' and extend toward the other side face 18, the first collective exhaust port 17 'is opposite to the first embodiment. It is obtained by constituting the upper exhaust port 16 'to three-dimensionally intersect, and other configurations are the same as those of the first embodiment.

  In addition, in the second embodiment, the first elbow exhaust pipe 22 curved downward and the second elbow exhaust pipe 23 curved downward are provided on the side surface 18 of the cylinder head 4. One elbow exhaust pipe line 22 communicates with the exhaust gas outlet 19 'at the first collective exhaust port 16', and the second elbow exhaust pipe line 23 communicates with the exhaust gas outlet 20 'at the second collective exhaust port 17'. When the flange connection is made in this manner, the first elbow exhaust pipe 22 is made to have a small radius of curvature R1, while the second elbow exhaust pipe 23 has a large radius of curvature R2. The pipe 22 is configured to bend outside the curve, and exhaust gas is not shown at the outlet ends 22a and 23a of both elbow exhaust pipes 22 and 23. Scan purifier or the exhaust pipe 21 for guiding the exhaust turbocharger flanges connected and directly to the configuration in which the flange connecting the exhaust gas purification device or exhaust turbocharger.

  The drawing shows the case where the first elbow exhaust pipe 22 and the second elbow exhaust pipe 23 are integrated, but the two elbow exhaust pipes are separate pipes. You may make it the structure of gathering together in an exit end.

  According to the second embodiment, the passage length from the exhaust port of each cylinder to the outlet end 23a of the second elbow exhaust pipe 23 in the second collective exhaust port 17 'is the second collective exhaust port 17'. In addition to the fact that the second collective exhaust port 17 'is three-dimensionally crossed above the first collective exhaust port 16', the second collective exhaust port 17 'is longer than the three-dimensional crossing below the first collective exhaust port 16'. , The second elbow exhaust pipe 23 is lengthened by an amount curved downward on the outside of the downward curve in the first elbow exhaust pipe 22, so that the second collective exhaust port 17 ′ and the second elbow exhaust pipe 23 are In the first collective exhaust port 16 ′ approaches the passage length from the exhaust port of each cylinder to the outlet end 22 a of the first elbow exhaust pipe 22, and the difference in the passage length between them is reduced. Since that, unequal emissions of the exhaust gas between the said 'the second collecting exhaust port 17' first collecting exhaust port 16, can be greatly improved over the case of the first embodiment.

  In the second embodiment, the first elbow exhaust pipe 22 and the second elbow exhaust pipe 23 are bent downward in an L-shape instead of being bent downward. In this case as well, the same effect can be achieved by bending the second elbow exhaust pipe 23 downwardly outside the downward bend in the first elbow exhaust pipe.

  Further, in the second embodiment, as shown in FIG. 5, the first collective exhaust port 16 'is viewed from the direction of the crank axis 2, that is, the row direction of each cylinder, as shown in FIG. The exhaust gas outlet 19 ′ in the collective exhaust port 16 ′ is curved upward and convex so as to be positioned at a position lower than the middle part of the first collective exhaust port 16 ′, so that both sets of the cylinder heads 4 are arranged. The height H ′ at the portion where the exhaust ports 16 ′ and 17 ′ are formed can be lowered by an amount corresponding to the position where the exhaust gas outlet 19 ′ at the first collective exhaust port 16 ′ is located at a low position. ing.

  Furthermore, also in the second embodiment, the exhaust gas outlets 19 'and 20' in both the collective exhaust ports 16 'and 17' are vertically moved to an intermediate position between the second cylinder A2 and the third cylinder A3. It is arranged in two stages, is configured in a horizontally long shape in the column direction of the cylinders, and between the first cylinder A1 and the exhaust gas outlet 19 'of the first collective exhaust port 16'. Of course, the portion and the portion between the fourth cylinder A4 and the exhaust gas outlet 19 'are configured to incline outward toward the exhaust gas outlet 19' as in FIGS. It is.

  Each of the above embodiments is applied to an in-line four-cylinder internal combustion engine 1 having four cylinders with respect to one crankshaft. However, the present invention is not limited to this. Needless to say, in a V-type eight-cylinder internal combustion engine having four cylinders in each bank, the same applies to both banks.

1 is a plan view of an internal combustion engine according to a first embodiment of the present invention. FIG. 2 is a side view taken along the line II-II in FIG. 1. FIG. 3 is an enlarged front view taken along the line III-III in FIG. 1. FIG. 4 is an enlarged sectional view taken along line IV-IV in FIG. 3. 1 is a longitudinal front view of an internal combustion engine according to a first embodiment of the present invention. FIG. 6 is a side view taken along the line VI-VI in FIG. 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal combustion engine A1 1st cylinder A2 2nd cylinder A3 3rd cylinder A4 4th cylinder 2 Crank axis 3 Cylinder block 4 Cylinder head 5 Combustion chamber 6 Intake port 7 Exhaust port 8 Intake valve 9 Exhaust valve 10 Exhaust valve cam shaft 11 Rocker arm 12 Valve mechanism for exhaust valve 13 Cylinder head cover 15 Intake port 16, 16 'First collective exhaust port 17, 17' Second collective exhaust port 18 Side surface of cylinder head 19, 19 ', 20, 20' Exhaust gas outlet 21 Exhaust line 22 First elbow exhaust line 23 Second elbow exhaust line

Claims (7)

  In a four-cycle multi-cylinder internal combustion engine in which four cylinders are arranged in a row, in the cylinder head, in the first cylinder and the fourth cylinder located at both ends in the row direction among the four cylinders A first collective exhaust port in which exhaust ports gather is formed to extend in the row direction of the cylinders, and a second cylinder located between the first cylinder and the fourth cylinder among the four cylinders And a second collective exhaust port for collecting exhaust ports in the third cylinder is formed so as to extend three-dimensionally crossing the first collective exhaust port, and communicates with the first collective exhaust port on a side surface of the cylinder head. The exhaust gas outlet and the exhaust gas outlet communicating with the second collective exhaust port are opened separately or in a single cylinder opening in a multi-cylinder internal combustion engine. Structure of de.   2. The structure of a cylinder head in a multi-cylinder internal combustion engine according to claim 1, wherein the second collective exhaust port is configured to three-dimensionally intersect the lower side of the first collective exhaust port.   3. The part according to claim 2, wherein the exhaust gas outlet of the second collective exhaust port is lower than the middle portion of the second collective exhaust port when the second collective exhaust port is viewed from the column direction of the cylinders. A structure of a cylinder head in a multi-cylinder internal combustion engine, wherein the structure is curved in an upwardly convex shape so as to be located at   The exhaust gas outlet in the first collective exhaust port and the exhaust gas outlet in the second collective exhaust port according to any one of claims 1 to 3, wherein the second cylinder in the row direction of the cylinders And a cylinder head structure in a multi-cylinder internal combustion engine, wherein the opening is arranged in two upper and lower stages at an intermediate position between the first cylinder and the third cylinder.   In the first aspect of the present invention, the second collective exhaust port is configured to three-dimensionally intersect the upper side of the first collective exhaust port, and the exhaust gas outlet at the first collective exhaust port; An exhaust gas outlet at the collective exhaust port is opened in two upper and lower stages at an intermediate position between the second cylinder and the third cylinder in the column direction of the cylinder, while the side surface of the cylinder head has the first A first elbow exhaust pipe curved downward or bent in communication with an exhaust gas outlet in the collective exhaust port; and a second elbow exhaust pipe curved in downward direction in communication with the exhaust gas outlet in the second collective exhaust port. Connect and bend or bend the second elbow exhaust pipe of both elbow exhaust pipes downwardly outside the downward curve or bend in the first elbow exhaust pipe. Structure of a cylinder head in a multi-cylinder internal combustion engine, wherein.   The exhaust gas outlet in the first collective exhaust port and the exhaust gas outlet in the second collective exhaust port that open to the side surface of the cylinder head in the column direction of each cylinder according to any one of claims 1 to 5. A structure of a cylinder head in a multi-cylinder internal combustion engine characterized by having a horizontally long shape.   7. The method according to claim 5, wherein portions of both sides of the first collective exhaust port sandwiching the exhaust gas outlet opening on a side surface of the cylinder head are directed to the exhaust gas outlet in a plan view. A structure of a cylinder head in a multi-cylinder internal combustion engine which is inclined outward.

Images