JP2015059492A - Cylinder head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylinder head capable of suppressing excessive temperature rising.SOLUTION: A cylinder head 1 includes: an intermediate cooling jacket 14 through which cooling water flows; exhaust gas passages 21 through which exhaust gas flows; a first merging part 22 for merging some of a plurality of the exhaust gas passages 21; and a second merging part 23 for merging the remaining exhaust gas passages of a plurality of the exhaust gas passages 21. The intermediate cooling jacket 14 is formed in a partition wall 11 between the first merging part 22 and the second merging part 23. A communication passage 16 communicating to the intermediate cooling jacket 14 is formed on the partition wall 11. The communication passage 16 is formed by using a drill.

Description

  The present invention relates to a cylinder head.

  The cylinder head of Patent Document 1 includes four exhaust passages, a first merging portion for joining two exhaust passages of the four exhaust passages, and the remaining two of the four exhaust passages. And a second merging portion that merges the exhaust passages. The 1st junction part and the 2nd junction part are arranged at intervals.

  Further, the cylinder head is formed with four exhaust passages and an upper cooling jacket and a lower cooling jacket for cooling each merging portion. An intermediate cooling jacket is formed on the lower cooling jacket. The intermediate cooling jacket is formed between the merging portions in the cylinder head. Each exhaust passage, each junction, and each cooling jacket are formed by casting using a core.

JP 2012-189076 A

The temperature of each merging portion is high because the exhaust gas from the respective exhaust passages merges. For this reason, the temperature of the cylinder head tends to increase.
On the other hand, the cylinder head of Patent Document 1 has a large core for preventing the core for forming the intermediate cooling jacket from being broken. For this reason, the passage cross-sectional area of the intermediate cooling jacket is increased. For this reason, the flow rate of the cooling water flowing into the intermediate cooling jacket from the lower cooling jacket is reduced. For this reason, it becomes difficult for the cooling water in the intermediate cooling jacket to circulate, and the cylinder head may not be efficiently cooled even if the intermediate cooling jacket is provided. For this reason, it is difficult to suppress the high temperature of the cylinder head.

  An object of this invention is to provide the cylinder head which can suppress high temperature.

  The cylinder head includes a plurality of exhaust passages through which exhaust discharged through an exhaust port is circulated, a first merging portion that joins some of the exhaust passages, and the first merging portion And formed in a partition wall between the second merging portion that joins the remaining exhaust passages of the plurality of exhaust passages, and the first merging portion and the second merging portion. An intermediate cooling jacket, and a communication passage formed in the partition wall by processing using a drill and communicating with the intermediate cooling jacket.

  The communication passage formed by processing using a drill can have a smaller passage cross-sectional area than the passage formed by the core. For this reason, the flow rate of the cooling water flowing through the communication path is increased. For this reason, the cooling water introduced from the communication passage flows into the intermediate cooling jacket vigorously. This increases the flow rate of the cooling water in the intermediate cooling jacket. For this reason, it becomes easy to circulate the cooling water in the intermediate cooling jacket. Thereby, a partition can be efficiently cooled with the cooling water which flows in the inside cooling jacket. Therefore, high temperature of the cylinder head is suppressed.

The typical perspective view of the cylinder head of an embodiment. (A) Sectional drawing of Z1-Z1 line of FIG. 1, (b) Sectional drawing of Z2-Z2 line of Fig.2 (a).

The configuration of the cylinder head 1 will be described with reference to FIGS. 1 and 2.
The cylinder head 1 is attached to an in-line four-cylinder internal combustion engine (not shown) provided with a twin scroll type supercharger (not shown). As shown in FIG. 1, the cylinder head 1 is integrated with an exhaust manifold 20 through which exhaust flows.

In addition to the exhaust manifold 20, the cylinder head 1 has a head body 10, a lower cooling jacket 13, an intermediate cooling jacket 14, and an upper cooling jacket 15.
The exhaust manifold 20 has four exhaust passages 21, a first joining portion 22, and a second joining portion 23.

  A branch portion 21 </ b> A is formed on the upstream side of each exhaust passage 21. The branch portion 21A is connected to an exhaust port (not shown). The branch portion 21A branches each exhaust passage 21 into two. The first joining part 22 joins the downstream side of the two exhaust passages 21 of the four exhaust passages 21. The second joining portion 23 joins the downstream side of the remaining two exhaust passages 21 of the four exhaust passages 21. The second merging portion 23 is arranged with a gap from the first merging portion 22.

  As shown in FIG. 2A, the head main body 10 has a partition wall 11. The partition wall 11 constitutes a portion between the joining portions 22 and 23. The head main body 10 has a mounting surface 12. In the mounting surface 12, the junctions 22 and 23 are open. A supercharger is attached to the attachment surface 12 via a gasket (not shown).

  The lower cooling jacket 13 is formed in the lower portion of each exhaust passage 21 in the head body 10. As shown in FIG. 1, the lower cooling jacket 13 covers each exhaust passage 21 from the lower side. The lower cooling jacket 13 is supplied with cooling water for cooling the internal combustion engine from a cooling water passage (not shown) of the cylinder block.

  As shown in FIG. 2A, the intermediate cooling jacket 14 is formed in the partition wall 11. As shown in FIG. 1, the intermediate cooling jacket 14 covers the first junction 22 from the lower side and the second junction 23 from the upper side. The intermediate cooling jacket 14 extends in the direction in which the exhaust passages 21 are arranged.

  As shown in FIG. 2A, the upper cooling jacket 15 is formed in the upper portion of each exhaust passage 21 in the head body 10. As shown in FIG. 1, the upper cooling jacket 15 covers each exhaust passage 21 from above. The upper cooling jacket 15 communicates with the lower cooling jacket 13. Cooling water is supplied to the upper cooling jacket 15 from the lower cooling jacket 13.

Next, the internal configuration of the partition wall 11 will be described with reference to FIG.
As shown in FIG. 2B, two communication paths 16 are formed in the partition wall 11. The two communication passages 16 are formed with an interval in the direction in which the intermediate cooling jacket 14 extends. The communication path 16 communicates the lower cooling jacket 13 and the intermediate cooling jacket 14. The cooling water in the lower cooling jacket 13 is supplied to the intermediate cooling jacket 14 via the communication path 16. As shown in FIG. 2A, the communication path 16 is formed linearly toward the end wall 11 </ b> A that constitutes the mounting surface 12. The outlet of the communication path 16 faces the end wall 11A. The communication path 16 is formed by drilling using a drill after forming the cylinder head 1.

With reference to FIG. 2, the operation and effect of the cylinder head 1 of the present embodiment will be described.
When the temperature of the cylinder head 1 is increased, cracks may occur in the openings of the merging portions 22 and 23, or a gasket may blow through between the supercharger and the mounting surface 12.

  Therefore, in order to cool the cylinder head 1, an intermediate cooling jacket 14 and a communication passage 16 that guides cooling water to the intermediate cooling jacket 14 are formed in the partition wall 11. Since the communication passage 16 is formed by drilling a drill, the passage cross-sectional area is smaller than a communication passage formed by casting using a core (hereinafter referred to as “comparison communication passage”). For this reason, the flow rate of the cooling water passing through the communication passage 16 is higher than the flow rate of the cooling water passing through the comparison communication passage. Therefore, the cooling water that passes through the communication passage 16 flows into the intermediate cooling jacket 14 more vigorously than the cooling water that passes through the comparison communication passage. For this reason, the flow rate of the cooling water in the intermediate cooling jacket 14 is increased. Thereby, since the cooling water in the intermediate cooling jacket 14 is easily circulated, the partition wall 11 can be efficiently cooled by the cooling water flowing in the intermediate cooling jacket 14.

  In addition, as shown in FIG. 2B, the cooling water in the communication path 16 collides with the end wall 11 </ b> A that faces the outlet of the communication path 16 in the partition wall 11. Thereby, the end wall 11A is cooled. Since end wall 11A constitutes attachment surface 12, attachment surface 12 is cooled more effectively.

In addition, the cylinder head 1 of this embodiment can also be changed as follows, for example.
The communication passage 16 can be connected to another cooling water channel (not shown) of the internal combustion engine instead of the lower cooling jacket 13. In particular, the communication path 16 is preferably connected to a cooling water channel (not shown) having cooling water lower than the temperature of the cooling water in the lower cooling jacket 13. The communication passage 16 is preferably connected to a cooling water passage (not shown) having a higher flow rate than the flow rate of the cooling water in the lower cooling jacket 13.

  DESCRIPTION OF SYMBOLS 1 ... Cylinder head, 10 ... Head main body, 11 ... Partition wall, 11A ... End wall, 12 ... Mounting surface, 13 ... Lower cooling jacket, 14 ... Intermediate cooling jacket, 15 ... Upper cooling jacket, 16 ... Communication path, 20 ... Exhaust manifold, 21 ... exhaust passage, 21A ... branch portion, 22 ... first merging portion, 23 ... second merging portion.

Claims (1)

A plurality of exhaust passages through which the exhaust exhausted through the exhaust port circulates;
A first merging section that merges some of the plurality of exhaust passages;
A second merging portion that is arranged at an interval from the first merging portion and merges the remaining exhaust passages of the plurality of exhaust passages;
An intermediate cooling jacket formed in a partition wall between the first merging portion and the second merging portion;
And a communication passage formed in the partition wall by processing using a drill and communicating with the intermediate cooling jacket.