JP2006322333A - Cylinder head of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase cooling efficiency. <P>SOLUTION: This cylinder head 2 of an internal combustion engine 1 comprises a water jacket 10 having cooling water passages 11 and 12 allowing cooling water to flow therein along a predetermined route and a partition wall 13 projected from the distant side wall surface 11a of the cooling water passage 11 and formed along a predetermined route to divide the cooling water passage 11 into a plurality of flow passages 14 and 15. The partition wall 13 is separated from the near side wall surface 11b to form a clearance 16 between the partition wall 13 and the near side wall surface 11b in at least a part of a predetermined route so that a first cooling water flow passage 14 and a second cooling water flow passage 15 on both sides of the partition wall 13 among these plurality of flow passages can communicate with each other. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cylinder head provided with a water jacket through which cooling water flows.

There is known an internal combustion engine in which a plurality of cooling water passages are provided in a cylinder head, and the plurality of cooling water passages are separated by partition walls (see Patent Document 1). In addition, there is Patent Document 2 as a prior art document related to the present invention.
JP-A-60-85215 JP 2003-138937 A

  Since the cooling water does not flow through the portion where the partition wall is provided, the contact area between the cooling water and the cylinder head is reduced, and the cooling efficiency is lowered.

  Therefore, an object of the present invention is to provide a cylinder head of an internal combustion engine that can improve the cooling efficiency.

  The cylinder head according to the present invention includes a water jacket having a cooling water passage for circulating cooling water along a predetermined path, and protrudes from a wall surface of the cooling water passage, so as to divide the cooling water passage into a plurality of flow paths. A cylinder head of an internal combustion engine having a partition wall provided along a predetermined path, wherein one of the plurality of flow paths sandwiching the partition wall and the other flow path communicate with each other. In the at least part of the predetermined path, the partition wall is separated from the wall surface of the cooling water passage, and a gap is provided between the partition wall and the wall surface of the cooling water passage. The problem is solved (claim 1).

  According to the cylinder head of the present invention, since the gap is provided between the wall surface of the cooling water passage and the partition wall, the contact area between the wall surface of the cooling water passage and the cooling water can be increased by this gap. Therefore, the cooling efficiency can be improved.

  In one form of the cylinder head according to the present invention, the partition wall protrudes from a far side wall surface located far from the cylinder block of the internal combustion engine in the wall surface of the cooling water passage and is located in the vicinity of the cylinder block The gap may extend between the side wall surface and the gap may be provided between the partition wall and the neighboring side wall surface. Of the wall surface of the cooling water passage, the near side wall surface becomes hotter than the far side wall surface. Thus, by providing a gap to increase the contact area between the near side wall surface and the cooling water, the cooling efficiency is further improved. Can be made.

  In one form of the cylinder head of the present invention, the gap may be provided over the entire length of the predetermined path (Claim 3). By providing the gap in this way, the contact area between the wall surface of the cooling water passage and the cooling water can be further increased.

  In one embodiment of the cylinder head of the present invention, the tip of the partition wall facing the gap may be sharp. By sharpening the tip of the partition wall in this manner, the cooling water warmed in the gap can be quickly moved from the gap. Therefore, cooling water stagnation in the gap can be suppressed and boiling of the cooling water can be prevented.

  In one form of the cylinder head according to the present invention, the gap has a flow rate of cooling water flowing through a flow channel located on one side across the partition wall and a flow rate of cooling water flowing through a flow channel located on the other side. May be provided so as to cause a difference between the two (claim 5). In this case, the cooling efficiency of the water jacket can be adjusted by adjusting the flow rate of the cooling water flowing through each flow path. Therefore, for example, the internal combustion engine can be appropriately cooled according to the operating state of the internal combustion engine.

  As described above, according to the present invention, the contact area between the wall surface of the cooling water passage and the cooling water can be increased by providing a gap between the wall surface of the cooling water passage and the partition wall. Cooling efficiency can be improved.

  1 and 2 show an embodiment of an internal combustion engine in which the cylinder head of the present invention is incorporated. 1 shows a view of the cylinder head as viewed from the lower side of FIG. 2, that is, the cylinder block side, and FIG. 2 shows a cross-sectional view taken along line II-II in FIG. An internal combustion engine (hereinafter sometimes referred to as an engine) 1 is mounted on a vehicle as a power source for travel, and includes a cylinder head 2 and a cylinder block 3 as shown in FIG. A main body 4 and a cooling device 100 for circulating cooling water through the engine main body 4 are provided. The engine 1 has a plurality (four in FIG. 1) of cylinders 5, and the cylinder block 3 is formed with these cylinders 5 arranged in a line. As is well known, the cylinder head 2 is formed with an ignition port 6, an exhaust port 7, and a spark plug mounting hole 8 for mounting a spark plug (not shown) corresponding to each cylinder 5. As shown in FIG. 1, each cylinder 5 has two intake ports 6 and two exhaust ports 7 respectively.

  The cylinder head 2 includes a water jacket 10 around the intake port 6, the exhaust port 7 and the spark plug mounting hole 8. As shown in FIG. 2, the water jacket 10 includes a plurality of cooling water passages 11 and 12 for circulating cooling water along a predetermined path, and the cooling water passages 11 and 12 include a cooling device 100. Circulates the cooling water. As shown in FIGS. 1 and 2, a partition wall 13 is provided in the cooling water passage 11, and the first cooling water passage 14 and the second cooling water passage 15 are formed in the cooling water passage 11 by the partition wall 13. It is formed. As shown in FIGS. 1 and 2, the second cooling water passage 15 is formed on the exhaust port 7 side of the cylinder head 2, and the first cooling water passage 14 is more than the second cooling water passage 15. It is formed on the center side of the cylinder head 2.

  As shown in FIG. 1, the partition wall 13 is formed over the entire length of the cylinder head 2. Further, as shown in FIG. 2, the partition wall 13 protrudes from the far side wall surface 11 a located far from the cylinder block 3 in the wall surface of the cooling water passage 11 and is located near the cylinder block 3. It extends toward the side wall surface 11b, and its tip 13a is provided so as not to contact the neighboring side wall surface 11b. By providing the partition wall 13 in this way, a gap 16 is provided between the tip 13a of the partition wall 13 and the adjacent side wall surface 11b, and the first cooling water channel 14 and the second cooling water channel 15 are communicated with each other. . The gap 16 is formed so that a difference occurs between the flow rate of the cooling water flowing through the first cooling water channel 14 and the flow rate of the cooling water flowing through the second cooling water channel 15, in other words, the gap 16. The flow rate of the cooling water flowing through each cooling water channel is not adjusted by the cooling water that has passed through the cooling water channel and passed from one cooling water channel to the other cooling water channel. The gap 16 is provided over the entire length of a predetermined path of the cooling water passage 11.

  The cooling device 100 includes a cooling water pump 101 that sends cooling water to the water jacket 10 and the like of the engine body 4, a radiator 102 that cools the cooling water heated by the engine body 4, a cooling water pump 101, the radiator 102, and the engine And a circulation passage 103 connecting the main body 4. In addition, since the cooling water pump 101 and the radiator 102 may be the same as a well-known thing, detailed description here is abbreviate | omitted. As shown in FIG. 1, in the circulation passage 103, a flow rate switching valve 104 that adjusts the flow rates of cooling water sent from the cooling water pump 101 to the first cooling water flow channel 14 and the second cooling water flow channel 15, respectively. A first outlet shut-off valve 105 provided at the outlet 14a of the first cooling water passage 14 and opens and closes the outlet 14a, and a second outlet provided at the outlet 15a of the second cooling water passage 15 and opens and closes the outlet 15a. An outlet shut-off valve 106 is provided. FIG. 3 shows an example of the characteristics of the flow rate switching valve 104. 3 indicates the flow rate of the cooling water supplied to the first cooling water flow channel 14, and the flow rate Q 2 indicates the flow rate of the cooling water supplied to the second cooling water flow channel 15. Further, the flow rate Q in FIG. 3 indicates the sum of the flow rate Q1 and the flow rate Q2.

  The operations of the flow rate switching valve 104, the first outlet cutoff valve 105, and the second outlet cutoff valve 106 are controlled by an engine control unit (ECU) 200. The ECU 200 is a well-known computer unit that controls the operating state of the engine 1 by adjusting the amount of fuel injected into each cylinder 4. The ECU 200 closes the second outlet shut-off valve 104 when the engine 1 is started, for example, and sets the valve switching instruction value of the flow rate switching valve 104 to a value at which the flow rate Q2 is adjusted to substantially zero, that is, 0 (see FIG. 3). To do. As described above, the cooling of the exhaust gas can be suppressed by stopping the circulation of the cooling water in the second cooling water flow path 15 when the engine 1 is started. Therefore, for example, when an exhaust purification catalyst is provided downstream of the exhaust port 7, warming up of the exhaust purification catalyst can be promoted.

  As described above, according to this cylinder head 2, the cooling water flows into the gap 16 formed between the tip 13a of the partition wall 13 and the adjacent side wall surface 11b, and the wall surface of the cooling water passage 11 and the cooling water Increases the contact area. As a comparative example, FIG. 4 shows a cylinder head 2 in which the partition wall 13 is formed integrally with the far side wall surface 11a and the near side wall surface 11b, and no gap is provided between the far side wall surface 11a and the near side wall surface 11b and the partition wall 13. Show. 4 that are the same as those in FIG. 2 are assigned the same reference numerals, and descriptions thereof are omitted. As apparent from FIGS. 2 and 4, in the cylinder head 2 shown in FIG. 2, the cooling water flows into the gap 16, so that the wall surface of the cooling water passage 11 b contacts the cooling water more than the cylinder head 2 of FIG. 4. Wide area. Therefore, the cooling efficiency of the cylinder head 2 can be improved.

  FIG. 5 shows another embodiment of the cylinder head 2 of the present invention. As shown in FIG. 5, the cylinder head 2 is different from the above-described embodiment in that the tip 13a of the partition wall 13 is sharpened. Other parts are the same as those described above. Therefore, in FIG. 5, the same reference numerals are given to the portions common to the above-described embodiment, and the description thereof is omitted. In the cylinder head 2 of this embodiment as well, the gap 16 provided between the tip 13a and the adjacent side wall surface 11b has a flow rate of the cooling water flowing through the first cooling water channel 14 and the second cooling water channel 15. It is formed so that a difference may arise between the flow rate of the cooling water flowing through the.

  In this embodiment, since the tip 13a of the partition wall 13 is sharpened, the movement of the cooling water in the gap 16 can be promoted. For example, when the cooling water in the gap 16 is heated by the heat from the cylinder head 2, the heated cooling water is inhibited from moving by the tip 13 a of the partition wall 13 as indicated by an arrow A in FIG. 5. Start convection without. Thus, by convection of the cooling water in the gap 16, stagnation of the cooling water in the gap 16 can be suppressed and boiling of the cooling water can be prevented. Further, as described above, when the circulation of the cooling water in the second cooling water passage 15 is stopped at the time of starting the engine 1, the cooling water in the second cooling water passage 15 is agitated by this convection. be able to. Therefore, boiling of the cooling water in the second cooling water channel 15 can be prevented by this stirring.

  The present invention is not limited to the form described above, and may be implemented in various forms. For example, the gap between the wall surface of the cooling water passage and the partition wall may be provided only in a part of the section of the cooling water passage. For example, as shown in FIG. 6A, a part of the partition wall 13 is removed in a section near the combustion chamber formed in each cylinder 5 out of the total length of the partition wall 13, and a gap 16 is provided only in this section. It may be done. By providing the gap 16 in this manner, cooling of the cylinder head 2 in the vicinity of the combustion chamber can be promoted while forming a plurality of cooling water flow paths by the partition wall 13. FIG. 6B shows a modification of FIG. Even if a part of the partition wall 13 is removed in such a shape, the same effect as the partition wall 13 shown in FIG. Moreover, you may remove a part of partition 13 so that the clearance gap 16 may be provided between the wall surface of both the far side wall surface 11a and the near side wall surface 11b, and the partition 13, respectively. Thus, by providing a gap between both the wall surfaces and the partition wall 13, the cooling efficiency can be further improved. The shape for removing a part of the partition wall 13 is not limited to the shape shown in FIG. Depending on the state of the wall surface of the water jacket, etc., the cylinder head may be removed in various shapes so as to be appropriately cooled. Further, the tip 13a of the partition wall 13 facing the gap 16 may be sharp. By sharpening the tip 13a of the partition wall 13, the cooling water in the gap 16 can be easily moved. The gap shown in FIG. 6 also has a difference between the cooling water flow rate of the cooling water passage formed on one side across the partition wall and the cooling water flow rate of the cooling water passage formed on the other side. Formed as follows.

The figure which shows one form of the internal combustion engine in which the cylinder head of this invention was integrated. The figure which shows the cross section in the II-II line | wire of FIG. The figure which shows an example of the characteristic of a flow volume switching valve. The figure which shows the cylinder head without a clearance gap between the wall surface of a cooling water channel, and a partition. The figure which shows the other form of the cylinder head of this invention. It is a figure which shows the modification of the partition of this invention, (a) shows the partition from which a part was removed in the shape of a triangle, (b) shows the partition from which a part was removed in the shape of a rectangle.

Explanation of symbols

1 engine (internal combustion engine)
2 Cylinder Head 3 Cylinder Block 10 Water Jacket 11 Cooling Water Passage 11a Distant Side Wall Surface 11b Near Side Wall Surface 12 Cooling Water Passage 13 Partition Wall 14 First Cooling Water Channel 15 Second Cooling Water Channel 16 Gap

Claims (5)

A water jacket having a cooling water passage for circulating cooling water along a predetermined path, and a wall protruding from the wall surface of the cooling water path, and provided along the predetermined path to divide the cooling water path into a plurality of flow paths. A cylinder head of an internal combustion engine provided with a partition wall,
The partition wall is a wall surface of the cooling water passage in at least a part of the predetermined path such that one of the plurality of channels and the other channel sandwiching the partition communicate with each other. A cylinder head of an internal combustion engine, wherein a gap is provided apart from the partition wall and the wall surface of the cooling water passage. The partition wall protrudes from a far side wall surface located far from the cylinder block of the internal combustion engine among the wall surfaces of the cooling water passage and extends toward a near side wall surface located near the cylinder block,
The cylinder head according to claim 1, wherein the gap is provided between the partition wall and the adjacent side wall surface.   The cylinder head of the internal combustion engine according to claim 1, wherein the gap is provided over the entire length of the predetermined path.   The cylinder head of an internal combustion engine according to any one of claims 1 to 3, wherein a tip of the partition wall facing the gap is sharp. The gap is provided so that there is a difference between the flow rate of the cooling water flowing through the flow path located on one side of the partition and the flow rate of the cooling water flowing through the flow path located on the other side. The cylinder head of the internal combustion engine according to any one of claims 1 to 4, wherein the cylinder head is provided.

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