JP3511702B2 - Cylinder head cooling system - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder head cooling device. 2. Description of the Related Art For example, in a four-cycle engine of a motorcycle, a technique is known in which oil for cooling is actively sent to the inside of a cylinder head to cool an upper portion of a combustion chamber, which becomes hot, with oil. ing. This type of technology includes a cooling device in which a separate oil pipe is piped in a cylinder head, oil for cooling is sent to the oil pipe, and oil is injected from the oil pipe to an upper portion of a combustion chamber (for example, In addition, oil is injected into a cooling chamber above the combustion chamber through an oil injection hole from a bearing formed on a cylinder head side that supports a camshaft. In some cases, oil is returned to the crankcase through an oil drop hole provided on the same side as the oil injection hole. [0003] However, the conventional cylinder head cooling device has the following problems. That is, in the cooling device having the separate oil pipe, since a separate pipe component is required,
When constructing the oil passage in the cylinder head, the assembling work is troublesome, and the number of parts increases. On the other hand, in the case of injecting oil from the bearing into the cooling chamber, the oil drop hole and the oil injection hole are arranged on the same side in the chamber, so that the injected oil is injected. Flowed down into the oil drop hole without flowing enough through the cooling chamber,
There is a possibility that a sufficient cooling effect cannot be obtained. SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has an apparatus having a simple structure which does not require separate parts, and has a cylinder head in which a combustion chamber is efficiently cooled. It is an object to provide a cooling device. [0006] In order to achieve the above object, the present invention has the following arrangement. That is, the present invention provides a cooling chamber formed above a combustion chamber and through which oil for cooling the combustion chamber flows, and a bearing portion rotatably supporting a camshaft above the cooling chamber. An oil passage for supplying oil to a bearing surface of the bearing portion is formed inside the camshaft along an axial direction of the camshaft, and a cam chain of the bearing portion is provided.
Camshaft shaft on the cylinder head body side adjacent to the chamber
While the receiving part, an oil injection hole for injecting oil into the cooling chamber from the oil passage respectively open into the receiving surface and the cooling chamber is provided,
The center axis of the oil injection hole is approximately at the center of the combustion chamber.
The cooling chamber is inclined to face
On the opposite side to the cam chain chamber, Kamuche oil of the cooling chamber and the oil return passage is provided for returning the crankcase, oil from the cam chain chamber side
Flow through the entire cooling chamber on the opposite side of the cooling chamber
A cooling device of the cylinder head, characterized in that the. According to the present invention, oil flowing through the oil passage formed inside the camshaft is injected into the cooling chamber through the oil injection hole after lubricating the bearing. . Adjacent to the cam chain chamber in the bearing section
Camshaft bearing on the cylinder head body side
Are respectively provided on the receiving surface and the cooling chamber.
Open the oil passage from the oil passage to the cooling chamber.
Oil injection hole for injecting oil
The oil flows in from the cam chain chamber side in the cooling chamber. At the same time, oil injection holes, the central axis
Since the line is formed so as to be inclined toward the substantially central portion of the combustion chamber , the inflowing oil flows from the cam chain chamber side toward the center of the chamber in the cooling chamber. Then, the oil that has flowed through the center of the cooling chamber reaches the opposite side of the cam chain chamber, and returns to the crankcase through an oil return passage provided on the opposite side. [0008] Therefore, the oil in the cooling chamber
Since the entire cooling chamber flows from the cam chain chamber side to the opposite side of the cam chain chamber, the combustion chamber is efficiently cooled by the oil. Also, since the oil passage provided in the camshaft is used as a passage for cooling oil, it does not use a separate oil pipe,
The device is easily configured. Further, since the oil is used for lubricating the camshaft prior to cooling the combustion chamber, a decrease in oil pressure of the oil is also prevented. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of the engine according to the present embodiment as viewed from the rear, and FIG. 2 is a cross-sectional view of the structure around the cylinder head of the engine as viewed from the rear. FIG.
FIG. 4 is a plan view of the inside of the cylinder head with the head cover removed according to the present embodiment, and FIG. 4 is a bottom view of the cylinder head as viewed from the mating surface side with the cylinder. As shown in FIG. 1, the cooling device of the present embodiment is formed above a combustion chamber 2 and has a cooling chamber 4 through which oil for cooling the combustion chamber 2 flows, and a cooling chamber 4. Camshaft chamber 6 formed above
The camshaft chamber 6 cools a cylinder head 12 in which a bearing 10 for rotatably supporting the camshaft 8 is integrally formed. In this embodiment, as shown in FIGS. 1 and 2, an oil passage 14 formed inside the camshaft 8 along the axial direction thereof and supplying oil to a receiving surface 10 a of the bearing portion 10. Is provided. Also, the bearing 1
0 has an oil injection hole 16 that opens to the receiving surface 10a and the cooling chamber 4 and that injects oil from the oil passage 14 to the cooling chamber 4. The oil injection holes 16 are provided eccentrically on one side of the cooling chamber 4, and the opening 16 a on the cooling chamber 4 side is connected to the opening 1 on the receiving surface 10 a side.
6b is inclined so as to be located on the cylinder center line C side (corresponding to the center of the cooling chamber) with respect to 6b.
Further, an oil return passage 20 for returning oil in the cooling chamber 4 to the crankcase 18 is provided on the left and right sides of the cooling chamber 4. The configuration of each section of the embodiment will be described.
The engine 22 is, for example, an oil-cooled S mounted on a motorcycle.
As shown in FIG. 1, the OHC engine includes a crankcase 18, a cylinder 24 fastened to an upper portion of the crankcase 18, and a cylinder head 12 fastened to an upper end of the cylinder 24. For assembling these three parts, for example, fastening bolts or the like inserted vertically into the four corners of the cylinder 24 in plan view are used. The engine 22 is provided with an oil cooler 26 which has a vertically long and substantially rectangular shape and is located in front of the cylinder head 12 and unevenly distributed to the right with respect to the cylinder center line C in FIG. I have. The cylinder head 12 shown in FIG.
As shown in the figure, a head body 12a divided vertically with respect to the center axis of the camshaft 8 and including the combustion chamber 2, and a head cover 12 mounted and fixed to the head body 12a.
b. A bearing 10 and a bearing 28 for supporting the journal of the camshaft 8 are provided on the divided surfaces of the head body 12a and the head cover 12b, respectively. In FIG. 3, reference numerals 48a and 48b denote valve sliding holes in which shaft portions of the intake valve and the exhaust valve slide, respectively. As shown in FIG. 2 or FIG. 4, the combustion chamber 2 is a space formed in the head main body 12a so as to be depressed upward, and an upper wall 2a of the combustion chamber 2 is screwed into the cylinder head 12. Plug holes 2a1 and 2a1 are formed at the ends of the ignition plugs 30 and 30, respectively. A pair of intake ports 2a2 and 2a2 and a pair of exhaust ports 2a3 and 2a3 are radially arranged on the upper wall 2a of the combustion chamber 2. The cooling chamber 4 includes an intake port 2a.
A space formed integrally with the head main body 12a above the combustion chamber 2 so as to cover the entire combustion chamber 2 while avoiding the exhaust ports 2a2 and the exhaust ports 2a3 and 2a3. As shown in FIG. 2, the camshaft 8 has a sprocket 8a around which a cam chain 32 is wound around a shaft end on the right side. The cam chain 32 includes a cam chain chamber 32a formed inside the right side wall of each of the head cover 12b, the head body 12a, and the cylinder 24.
It is housed in. The oil passage 14 is formed so as to penetrate substantially along the central axis of the camshaft 8, and the bearings 10, 2
8 has a communication hole 14a formed in the axial direction for sending oil. The opening at the right end of the oil passage 14 is closed by a cap 34 fitted into the cylinder head 12, while the opening at the left end communicates with an oil guide hole 36 formed inside the head cover 12b. are doing. The oil guide hole 36 is provided in the oil passage 14.
A vertical hole 36a provided upward from the left end of the head cover 12b, and a horizontal hole 36b extending horizontally to the right from the upper end of the vertical hole 36a and opening on the right side of the head cover 12b. A pipe 38 having one end connected to the oil cooler 26 is provided in the opening at the right end of the horizontal hole 36b.
Are connected to each other. The oil injection hole 16 is provided in the cam chain chamber 32.
The oil passage 14 is formed in the bearing portion 10 on the side of the head main body 2 a adjacent to the oil passage 14 a and has a smaller diameter than the inner diameter of the oil passage 14. The oil injection hole 16 is inclined so that its central axis is directed substantially toward the center of the combustion chamber 2, so that oil is sprayed obliquely onto the lower surface of the cooling chamber 4. The oil return passage 20, as shown in FIGS. 1 and 4, is a pair of front and rear passages provided on the opposite side (left side in FIG. 1) of the cooling chamber 4 from the cam chain chamber 32a. Are formed on the left side of the combustion chamber 2, that is, inside the left side wall of the head body 12a. The lower end of the oil return passage 20 is open at the mating surface with the cylinder 24, and an oil return passage 40 is formed from the portion of the mating surface on the cylinder 24 side facing the opening to the lower end of the cylinder 24. Have been. further,
An oil return passage 42 is also provided inside the left side wall of the crankcase 18 so as to be continuous with the oil return passage 40. In this embodiment having the above configuration,
The oil pumped from the oil pan 18a below the crankcase 18 to the oil cooler 26 is
After being cooled through the inside 6, it is guided to the right side of the head cover 12b via a pipe 38. Head cover 12b
Inside, the oil reaches the left shaft end of the camshaft 8 through the oil guide hole 36 and flows into the oil passage 14 inside the camshaft 8. Then, the oil flows out of the camshaft 8 from the communication hole 14a, and lubricates the bearing portions 10, 28. The oil that has lubricated the bearings 10 and 28 is injected into the cooling chamber 4 from the oil injection holes 16. At this time, the injected oil is supplied to the cooling chamber 4.
And flows from the right side on the cam chain chamber 32a side to the left side on the opposite side in the cooling chamber 4. The oil flowing to the left side of the cooling chamber 4 is supplied to the oil return passage 20, the oil return passage 40 inside the cylinder 24,
Further, the oil flows down the oil return passage 42 on the side of the crankcase 18 and enters the crankcase 18. It returns and returns to the oil pan 18a. Therefore, according to the cooling device of this embodiment, the oil flows through the entire cooling chamber 4 from the right side to the left side of the cooling chamber 4, so that the combustion chamber 2
Can be efficiently cooled. Further, since the oil passage 14 provided in the camshaft 8 is used as a passage for the cooling oil, the device can be easily configured without using a separate oil pipe. Further, since the oil is used for lubricating the camshaft 8 before cooling the combustion chamber 2, it is possible to prevent a decrease in oil pressure of the oil. This embodiment is a preferred embodiment of the present invention, and the technical scope of the present invention is not limited to this embodiment. As described above, according to the present invention, in the cylinder head cooling device, the device can be configured with a simple structure that does not require a separate component.
The combustion chamber can be efficiently cooled.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of an engine according to the present embodiment as viewed from the back. FIG. 2 is an enlarged cross-sectional view of a structure around a cylinder head of the engine according to the embodiment, viewed from the back. FIG. 3 is a plan view of the inside of the cylinder head with the head cover according to the embodiment removed. FIG. 4 is a bottom view of the cylinder head according to the present embodiment as viewed from the mating surface side with the cylinder. [Description of Signs] 2 Combustion chamber 4 Cooling chamber 6 Camshaft chamber 8 Camshaft 10 Bearing 10a Receiving surface 12 Cylinder head 14 Oil passage 16 Oil injection hole 16a Cooling chamber side opening 16b Receiving surface side opening 18 Crank Case 20 Oil return passage C Center of cylinder (equivalent to center of cooling chamber)

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁷ identification symbol FI F02F 1/38 F02F 1/38 Z (58) Investigated field (Int.Cl. ⁷ , DB name) F01P 3/02 F01M 1 / 06 F01M 9/10 F01P 3/20 F02F 1/38

Claims (1)

Claims: 1. A cooling chamber formed above a combustion chamber and through which oil for cooling the combustion chamber flows, and a camshaft above the cooling chamber. An oil passage for supplying oil to a bearing surface of the bearing portion is formed inside the camshaft along a camshaft axial direction. The cylinder adjacent to the cam chain chamber in the bearing portion
The camshaft bearing portion Heddo body side, while the oil injection hole for injecting oil into the cooling chamber from the oil passage respectively open into the receiving surface and the cooling chamber are provided, the oil injection holes , That
Central axis is inclined to face the substantially central portion of the combustion chamber, further, anti the cam chain chamber of the cooling chamber
On the opposite side, an oil return passage for returning oil in the cooling chamber to the crankcase is provided, and the oil flows from the cam chain chamber side to the opposite side of the cam chain chamber.
A cooling device for a cylinder head, characterized in that it flows through the entire cooling chamber .