JPH0643443Y2 - Bearing device for camshaft in internal combustion engine - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a cam shaft arranged at the top of a cylinder head,
The present invention relates to a bearing device for axially supporting a cylinder head.

[Conventional technology]

It is well known that the lubrication of the cam shaft rotatably supported on the top of the cylinder head is performed by immersing a part of the cam in the lubricating oil accumulated in the oil sump chamber formed in the lower part of the cam shaft. The lubricating oil in the oil sump chamber becomes oil droplets with the rotation of the cam shaft, scatters throughout the cylinder head cover, and is lost together with blow-by gas extracted from the cylinder head cover to the intake system and the like. The amount of lubricating oil increases.

Therefore, Japanese Utility Model Laid-Open No. 55-137203 discloses a prior art.
It has been proposed to provide a shield plate on the side of the cam shaft for restricting the flow of oil droplets scattered by the rotation of the cam shaft.

[Problems to be solved by the device]

However, since the shield plate in this prior art is constructed separately from the bearings of the cylinder head and the cam shaft and is attached to the cylinder head with bolts or the like, the number of parts increases. At the same time, the number of assembling steps is increased, which leads to an increase in cost and, moreover, the space for mounting the shielding plate must be secured, which leads to an increase in the size of the cylinder head.

The present invention, as disclosed in, for example, Japanese Utility Model Publication No. 60-65305, discloses a plurality of bearing seats in which the cam shaft described at the top of the cylinder head is formed integrally with the cylinder head, and the bearings. In a bearing device of the type that is axially supported by a bearing cap body fastened to each of the seats with a bolt, the plurality of bearing cap bodies are simultaneously cast in a state where they are arranged side by side and are continuous with each other. Paying attention to the fact that each bearing cap body is cut and manufactured, and using the runner that connects the bearing cap bodies to each other during casting, the above problem, that is, with the rotation of the cam shaft It is intended to reduce the scattering of oil droplets.

[Means for Solving the Problems]

To achieve this object, the present invention provides a plurality of bearing seats integrally provided on the cylinder head with a cam shaft on the top of the cylinder head, and a bearing cap body fastened to each of the bearing seats by a bolt. While arranging to support the shaft,
An oscillating arm shaft for intake valve and an oscillating arm shaft for exhaust valve are mounted on the upper surface of the bearing cap body in parallel with each other and in parallel with the cam shaft, and further, a spark plug is attached to the cylinder head. In the internal combustion engine, wherein the insertion pipe is mounted such that the ignition plug insertion pipe is inclined from the substantially central portion of the combustion chamber on the lower surface of the cylinder head toward the outside of the swing arm shaft for the intake valve. When the bearing caps of the above are simultaneously cast in a lined state, the runners that connect the side surfaces of each bearing cap are left attached to the side of each bearing cap, and Is arranged at a site of a space surrounded by the side surface of the bearing cap, the lower surface of the intake valve swing arm shaft, and the side surface of the spark plug insertion tube.

[Function and effect of device]

With this structure, when a space surrounded by the side surface of the bearing cap, the lower surface of the swing arm shaft for the intake valve, and the side surface of the spark plug insertion tube is simultaneously cast with the bearing cap bodies arranged side by side. In addition, since it can be closed by the runner piece that connects the side surfaces of each bearing cap body, it is possible to reliably reduce the oil droplets scattered with the rotation of the camshaft from splashing outward from the space. You can do it.

Further, the runner piece is for simultaneously casting a plurality of bearing cap bodies in a lined state, and is constructed separately from the cylinder head and the bearing cap body like the shielding plate in the above-mentioned prior art. Since it is not mounted on the cylinder head, it is possible to prevent an increase in the number of parts and the number of assembling steps.

Therefore, according to the present invention, it is possible to reduce the scattering of oil droplets associated with the rotation of the cam shaft without increasing the cost and increasing the size of the cylinder head.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. This drawing includes two intake valves 3 and two intake valves 4 in each of the cylinders A1 and A2. A case where the present invention is applied to an internal combustion engine that is opened and closed by a single camshaft 2 is shown. The single camshaft 2 is arranged parallel to the cylinder row on the upper surface of the cylinder head 1 indicated by reference numeral 1. The cam shaft 2 is pivotally supported by a plurality of bearing portions 5.

Each of the bearing portions 5 includes a bearing seat 6 integrally formed on the upper surface of the cylinder head 1 and a bearing cap body 8 fastened to the bearing seat 6 with a pair of left and right bolts 7. . An oil sump chamber 16 is formed below the cam shaft 2.

Reference numeral 9 indicates a swing arm shaft for the intake valve, and reference numeral 10 indicates a swing arm shaft for the exhaust valve. These both swing arm shafts 9 and 10 are left and right on the upper surface of each bearing cap body 8. Camshaft 2 on both sides
Are arranged in parallel with each other, and are simultaneously fastened by bolts 7 for fastening the bearing cap bodies 8 to the bearing seats 6.

The intake valve swing arm shaft 9 has a swing arm 11 for each of the two intake valves 3 in one cylinder, and the exhaust valve swing arm shaft 10 has a swing arm 11 for one cylinder. A swing arm 12 for each of the exhaust valves 4 is rotatably fitted therein.

In addition, the cylinder head 1 has a spark plug insertion tube 15
The spark plug insertion tube 15 is mounted so as to incline toward the outside of the intake valve swing arm shaft 9 from a substantially central portion in a combustion chamber (not shown) on the lower surface of the cylinder head 1.

Reference numeral 14 denotes a cylinder head cover that entirely covers the cam shaft 2, both swing arm shafts 9 and 10, each swing arm 11 and 12, etc. on the upper surface of the cylinder head 1.

Then, each bearing cap body 8 in each bearing portion 5
As shown in FIG. 5, after arranging them in a line, they are simultaneously cast with the runner pieces 13 connecting them to each other.
When casting by cutting the runner pieces 13 in the bearing cap bodies 8 at the positions of the lines 18 in their respective intermediate portions, the respective bearing cap bodies 8 are connected to each other during the casting. When the runner piece 13 is attached to the bearing seat 6 with respect to each bearing cap 8, the side surface of the bearing cap 8, the lower surface of the intake valve swing arm shaft 9 and the side surface of the spark plug insertion tube 15 are separated from each other. Arrange the parts of the space surrounded by the three parties.

With this structure, each bearing cap body 8 is manufactured in a state in which the runner piece 13 is integrally provided, and the runner piece 13 in each bearing cap body 8 causes the side surface of the bearing cap 8 and the Since the space surrounded by the lower surface of the intake valve swing arm shaft 9 and the side surface of the spark plug insertion tube 15 can be closed, as shown in FIG. By rotating in the direction, the oil droplets scattered from the oil reservoir chamber 8 in the direction of the arrow C can be reliably reduced by the runner piece 13.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a plan view, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 3 is a sectional view taken along line III-III of FIG. FIG. 4 is a sectional view taken along the line IV-IV in FIG. 1, and FIG. 5 is a diagram when a plurality of bearing cap bodies are cast in a row. 1 ... Cylinder head, 2 ... Cam shaft, 3 ... Intake valve,
4 ... Exhaust valve, 5 ... Bearing part, 6 ... Bearing seat, 7 ... Bolt, 8 ... Bearing cap body, 9 ... Intake valve swing arm shaft, 10 ... Exhaust valve swing arm Shaft, 13 …… runner piece, 18 …… cutting line, 15 …… spark plug insertion tube, 16 …… oil sump chamber.

 ─────────────────────────────────────────────────── --Continued front page (56) References Microfilm (JP, U ) A microfilm (JP, U) obtained by photographing the contents and drawings attached to the application of Japanese Utility Model Application No. 60-43180 (Japanese Utility Model Application No. 61-160210).

Claims (1)

[Scope of utility model registration request] 1. A cam shaft is supported on the top of a cylinder head by a plurality of bearing seats provided integrally with the cylinder head and a bearing cap body fastened to each of the bearing seats by a bolt. On the other hand, the swing arm shaft for the intake valve and the swing arm shaft for the exhaust valve are mounted on the upper surface of the bearing cap body in parallel with each other and in parallel with the cam shaft.
Further, a spark plug insertion tube is attached to the cylinder head such that the spark plug insertion tube is inclined from the substantially central portion of the combustion chamber on the lower surface of the cylinder head toward the outside of the intake valve swing arm shaft. In the internal combustion engine, the state in which the runner piece connecting the side surfaces of each bearing cap body to each other when the plurality of bearing cap bodies are simultaneously cast is attached to the side surface of each bearing cap body. And the runner piece is disposed at an air site surrounded by the side surface of the bearing cap, the lower surface of the intake valve swing arm shaft, and the side surface of the spark plug insertion tube. A camshaft bearing device in an internal combustion engine.