JP2007162519A - Cooling structure for cylinder head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve cooling performance and improve manufacturing property by modifying a water jacket structure of a cylinder head. <P>SOLUTION: In the cylinder head 1 having an exhaust gas collecting part collecting a plurality of exhaust ports 2 formed as one unit, the water jacket 11 cooling a combustion chamber part and the water jacket 21 cooling the exhaust gas collecting part (consists of an upper and a lower water jackets 21A, 21B and a water jacket 21C establishing communication of the same) are separately formed to enable to independently adjust cooling water flow rate to each water jacket 11, 21. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cooling structure for a cylinder head in which an exhaust collecting portion in which exhaust ports are gathered is integrally formed.

There is a cylinder head in which an exhaust collecting portion in which exhaust ports are gathered is integrally formed to make the engine compact.
In this type of cylinder head, in this type of cylinder head, water jackets are provided on both upper and lower sides of the exhaust collecting portion, and at least some of the plurality of oil passages provided in the exhaust port portions between the cylinders are provided with water jackets on both upper and lower sides. The structure is surrounded by a communicating water jacket.
JP 2002-70641 A

  However, in the cooling structure of Patent Document 1, the water jacket of the exhaust collecting portion and the water jacket of the combustion chamber portion of each cylinder are formed so as to communicate with each other in a direction perpendicular to the cylinder row direction. Since the water flow rate is a structure that cannot be adjusted independently, a large amount of cooling water flows through the water jackets on the upper and lower sides of the exhaust assembly, and the cooling water flow rate around the combustion chamber and spark plug, which is a high-temperature part, decreases. It was supposed to reduce the combustion efficiency.

In addition, as described above, since the water jacket on the upper and lower sides of the exhaust collecting portion and the water jacket on the combustion chamber portion of each cylinder are integrally formed, the water jacket that connects the upper and lower water jackets is However, there is a problem that it is necessary to form the core with a separate core and the manufacturing process is increased accordingly.
The present invention has been made paying attention to such a conventional problem, and provides a cooling structure for a cylinder head that can perform cooling according to a required cooling amount of a portion to be cooled and can reduce the manufacturing process. With the goal.

  For this reason, the present invention provides a water jacket for cooling a combustion chamber portion and a water jacket for cooling an exhaust collection portion, in a cylinder head integrally formed with an exhaust collection portion in which a plurality of exhaust ports are gathered. The cooling water flow rate to the jacket was divided and formed so as to be independently adjustable.

According to the present invention, the water jacket of the combustion chamber portion and the water jacket of the exhaust collecting portion are formed separately, and the flow rate of each cooling water can be adjusted independently. Necessary cooling water flow rate can be secured.
In addition, since the water jacket of the exhaust collecting part is independent from the water jacket of the combustion chamber part, the water jacket of the exhaust collecting part including the water jackets on both the upper and lower sides and the communicating part water jackets connecting them are contained in one. It can be formed by a child, the manufacturing process can be reduced, and the cost can be reduced.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows a longitudinal sectional structure of a cylinder head of an engine (internal combustion engine) showing an embodiment of the present invention.
The cylinder head 1 of the engine constitutes an exhaust port 2, an intake port 3, a combustion chamber 4, an exhaust side fastening surface 5, an intake side fastening surface 6, a combustion chamber portion water jacket 11, and an exhaust collecting portion water jacket 21.

The combustion chamber water jacket 11 includes a spark plug water jacket 11A, an intake port lower water jacket 11B and an intake port surrounding water jacket 11C, an exhaust port lower water jacket 11D, an exhaust port upper water jacket 11E, and an exhaust port surrounding water. It is comprised with the jacket 11F.
On the other hand, an exhaust collecting portion water jacket 21 formed separately from the combustion chamber portion water jacket 11 includes an exhaust collecting portion lower water jacket 21A, an exhaust collecting portion upper water jacket 21B, and these exhaust collecting portion lower water jackets 21A, The exhaust water gathering section upper water jacket 21B is configured to communicate with a communication section water jacket 21C.

FIG. 2 shows the water jacket shape of the cylinder head and the flow of cooling water.
The structure of the water jacket of the cylinder head includes a spark plug portion 31 that is not a water jacket, an exhaust valve guide portion 32, a combustion chamber water jacket 11 that is provided so as to surround the head bolt portion 33, and the combustion chamber water jacket. 11, an exhaust collecting portion that is on the exhaust side across an oil passage 51 that is not a water jacket and is configured by the exhaust collecting portion lower water jacket 21A, the exhaust collecting portion upper water jacket 21B, and the communicating portion water jacket 21C. It consists of a water jacket 21.

Here, the exhaust collecting unit water jacket 21 composed of the exhaust collecting unit lower water jacket 21A, the exhaust collecting unit upper water jacket 21B, and the communication unit water jacket 21C is divided from the combustion chamber unit water jacket 11 and independently. Since it is provided, it can be formed by one core.
A cooling water control valve 41 is provided at the cooling water outlet of the exhaust collecting unit water jacket 21.

The cooling water control valve 31 is controlled in opening degree according to the engine warming state based on the engine cooling water temperature detected by the water temperature sensor, thereby adjusting the cooling water flow rate.
Next, the flow of cooling water will be described.
The cooling water inlet flow W1 is divided into an intake port lower flow W2, a spark plug portion flow W3, and an exhaust collecting portion lower flow W6.

As for the separated cooling water flows, the intake port lower part flow W2 flows from the rear end cylinder to the cooling water outlet W11, and the spark plug part flow W3 flows to the cooling water outlet W11 via the inter-cylinder flows W4 and W5. .
The exhaust collecting portion lower flow W6 flows to the exhaust collecting portion lower water jacket 21A, and part of the exhaust collecting portion lower flow W6 passes through a plurality of communicating portion water jackets 21C to flow into the exhaust collecting portion upper water jacket 21B. It becomes a merged flow W9 and flows to the cooling water outlet W11 via the flow W10 of the cooling water control valve 41 part.

If configured as described above, the water jacket of the combustion chamber portion and the exhaust collecting portion is formed separately, so that the flow rate of each cooling water can be adjusted independently, and the cooling of the combustion chamber portion that originally needs cooling is required. Since a sufficient water flow rate can be ensured, knocking characteristics can be prevented from being lowered and combustion efficiency can be maximized.
In addition, the communication part water jacket 21C that connects the exhaust water collecting part lower water jacket 21A and the exhaust gas collecting part upper water jacket 21B has a total of four locations between the cylinders and at the front and rear ends, and these are formed by one core. The flow of the water jackets 21A and 21B on both sides can be made uniform, and the communication portion water jacket 21C is evenly arranged, so that the strength of the core in the core formation stage of the exhaust assembly water jacket 21 And can be integrally formed with a high yield.

Further, a cooling water control valve 41 is provided on the outlet side of the exhaust collecting portion water jacket 21, and the cooling water flow rate can be controlled according to the warm-up state (water temperature) of the engine.
Specifically, when the engine is started, the exhaust water temperature can be increased quickly by closing the coolant control valve 41 and shutting off the coolant flow, thereby promoting warm-up.
In response to the heater performance requirement, the heater performance can be improved by energizing the cooling water control valve 41 and increasing the cooling water flow rate while the engine is warming up.

Further, in a high-load high-rotation region where the radiator capacity is limited, the cooling water flow rate can be reduced by setting the cooling water control valve 41 as an intermediate opening, so that an increase in the radiator capacity can be prevented.
As described above, since it is possible to prevent the cooling system from being maximized while improving the heater performance, an optimum cooling system can be obtained.

The longitudinal cross-sectional view of the cylinder head which shows one Embodiment of this invention. The cross-sectional view of a cylinder head same as the above.

Explanation of symbols

1 Cylinder head
2 Exhaust port
4 Combustion chamber
11 Combustion chamber water jacket
21 Exhaust assembly water jacket
21A Exhaust assembly lower water jacket
21B Exhaust assembly upper water jacket
21C Communication water jacket

Claims (4)

In the cylinder head that integrally forms an exhaust collecting portion in which a plurality of exhaust ports are gathered,
Cylinder characterized in that a water jacket for cooling the combustion chamber portion and a water jacket for cooling the exhaust collecting portion are divided and formed so that the cooling water flow rate to each water jacket can be adjusted independently. Head cooling structure.   2. The cooling structure for a cylinder head according to claim 1, wherein the water jacket for cooling the exhaust collecting portion is composed of water jackets on both upper and lower sides of the exhaust collecting portion and a water jacket communicating these.   The water jacket that communicates the water jackets on both the upper and lower sides of the exhaust collecting part is provided between both ends in the cylinder arrangement direction and between adjacent cylinders, and all the water jackets of the exhaust collecting part are formed by one core. The cooling structure for a cylinder head according to claim 2, wherein the cooling structure is formed.   The cylinder head cooling structure according to any one of claims 1 to 3, wherein a control valve for adjusting a cooling water flow rate is disposed on a cooling water outlet side of the water jacket of the exhaust collecting portion.

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