JPH0619776Y2 - Camshaft Locating Plate Lubrication Structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a lubricating structure for a camshaft locating plate for positioning a camshaft provided in an internal combustion engine with respect to a cylinder head.

(Prior Art) A conventional lubrication structure for a camshaft locating plate will be described with reference to FIGS. 5 and 6.

FIG. 5 is a view showing the end of the camshaft 1 together with a part of the cylinder head 2. In the drawing, the large diameter portions 1a and 1b of the camshaft 1 are formed by the bearing holes 3 and 4 provided in the cylinder head 2. Each is supported. Camshaft 1
Is provided with an axial oil supply hole 5, and this oil supply hole 5 communicates with a bearing gap 7 between the tip end bearing hole 3 and the cam shaft 1 via a radial passage 6. There is. A sprocket 9 is fixed to the tip of the camshaft 1 via a bolt 8 screwed into one end of the oil supply hole 5,
The sprocket 9 is linked to a sprocket on the crankshaft side via a timing chain (not shown).

Large diameter portion 1 of camshaft 1 supported in the bearing hole 3
The end surface 10 of the a on the sprocket 9 side is flush with the end surface 11 of the cylinder head 2 in the portion supporting the large diameter portion 1a, and an annular camshaft locating portion is provided between the large diameter portion 1a and the sprocket 9. The plate 12 is interposed so as to close the bearing gap 7. As shown in FIG. 6, the camshaft locating plate 12 is fixed to the end surface 11 of the cylinder head 2 through bolts 13 and 13, and the thrust surfaces 12a and 12 on both sides thereof are fixed.
b has a planar shape.

Now, in such a lubricating structure of the camshaft locating plate 12, the lubricating oil that has reached the bearing gap 7 from the oil supply hole 5 of the camshaft 1 through the passage 6 is indicated by an arrow A in FIG.
As shown by, between the thrust surface 12a and the end surface 10 of the large diameter portion 1a of the camshaft 1, between the inner diameter surface of the camshaft locating plate 12 and the camshaft 1,
Further, it flows out through the space between the thrust surface 12b and the sprocket 9 to the outside.

(Problems to be solved by the invention) However, in such a conventional camshaft locating plate lubrication structure, from the oil supply hole 5 to the bearing gap 7
The lubricating oil that has reached the above point flows in the direction of arrow A while flowing in the direction of arrow B and directly flows out to the outside. This flow in the direction of arrow B is easier than the flow in the direction of arrow A because the passage resistance is small. Therefore, the amount of lubricating oil flowing in the direction of arrow A is reduced, and the thrust surfaces 12a and 12b of the camshaft locating plate 12 are insufficiently lubricated, resulting in abnormal wear.

(Means for Solving the Problems) In order to solve the above-mentioned problems of the prior art, the present invention provides a part of a cylinder head that supports a cam shaft with a bearing gap to be lubricated from the inside of the cam shaft. A camshaft that is fixed relative to each other and is interposed between the bearing support portion of the camshaft and a locking portion that is provided at a proper axial distance from the bearing support portion to fix the axial position of the camshaft. A lubricating structure for a locating plate, wherein a thrust surface of the camshaft locating plate facing the bearing support portion is provided with a first oil groove communicating with the bearing gap and isolated from the outside. A second oil groove, at least a portion of which communicates with the outside, is provided on the thrust surface facing the stopper, and the first oil groove and the second oil groove are provided.
The oil grooves are provided to face each other in a pair of upper and lower diametrical directions, and the first oil groove and the second oil groove are provided between the inner peripheral surface of the camshaft locating plate and the outer peripheral surface of the camshaft. Are communicated with each other through the gap of
The flow resistance of the lubricating oil through the first oil groove from the bearing clearance, the clearance between the camshaft locating plate and the camshaft, and the passage extending to the outside via the second oil groove is greater than the bearing clearance. The resistance is set to be almost equal to the flow resistance of the lubricating oil flowing on the opposite side of the camshaft locating plate.

(Operation) In the above configuration, the lubricating oil that reaches the bearing gap between the cylinder head and the camshaft has a gap between the inner peripheral surface of the camshaft locating plate and the camshaft from the first oil groove, and further the second oil. The oil flows out through the groove, and by providing the first oil groove and the second oil groove in this way, the flow resistance of the lubricating oil around the camshaft locating plate is reduced.

(Embodiment) Next, an embodiment of the present invention will be described with reference to FIGS. In this embodiment, the structure other than the camshaft locating plate is the same as the above-mentioned conventional example,
Similar members are designated by the same reference numerals, and description thereof will be omitted.

As shown in FIGS. 1 and 2, the camshaft locating plate 2 is provided on the thrust surface 22 a of the camshaft locating plate 22 facing the bearing gap 7.
Upper and lower first oil grooves 23a having the inner peripheral surface 22c of 2 as a base end,
23b are provided so as to face each other in the diametrical direction. These first oil grooves 23a and 23b do not reach the outer peripheral surface 22d of the camshaft locating plate 22, but the inner peripheral surface 22c.
It is formed so as to communicate only with the side and cross the bearing gap 7 as shown in FIG.

On the other hand, as shown in FIG. 3, on the thrust surface 22b facing the sprocket 9, upper and lower second oil grooves 24a, 24b formed so as to communicate from the inner peripheral surface 22c to the outer peripheral surface 22d face each other in the diametrical direction. It is provided.

Next, the operation of the lubricating structure of the camshaft locating plate 22 configured as described above will be described. The lubricating oil that reaches the bearing gap 7 from the oil supply hole 5 of the camshaft 1 through the passage 6 is indicated by an arrow in FIG. While flowing in the direction B and directly flowing out to the outside, it also flows in the direction of arrow A and passes through the first oil grooves 23a and 23b on the side of the thrust surface 22a and the inner peripheral surface 22c of the camshaft locating plate 22 and the camshaft 1.
Flows into the gap 25 between the outer peripheral surface and the outer peripheral surface and further flows out through the second oil grooves 24a and 24b on the thrust surface 22b side. Here, the first oil grooves 23a and 23b and the second oil groove 2
The flow resistance in the direction of arrow A is reduced by providing 4a and 24b, and such flow resistance is set to be substantially equal to the flow resistance in the direction of arrow B. Therefore, the thrust surface 2 of the camshaft locating plate 22
It is possible to sufficiently lubricate 2a and 22b.

The first oil grooves 23a and 23b and the second oil groove 24 as described above.
The flow resistance reducing action of a and 24b will be described in more detail with reference to FIG. 4. The outer peripheral surface of the cam shaft 1 facing the cam shaft locating plate 22 has a weight of the cam shaft 1, a driving force of the timing chain, and a rocker arm. As shown in the figure, it is pressed downward against the bearing hole 3 by a driving reaction force or the like. Therefore, the upper space of the bearing gap 7, that is, the upper space of the gap 25 becomes large,
The lubricating oil can easily flow from the upper first oil groove 23a through the gap 25. On the other hand, the lower first oil groove 23b
Since the lubricating oil is retained in the thrust surface 2
2a can be sufficiently lubricated. Also, the gap 25
The lubricating oil that has reached the second oil grooves 24a and 24b through the air easily flows out to the outside through the lower second oil groove 24b by the air flowing in from the upper part of the upper second oil groove 24a, and therefore Can be sufficiently lubricated.

(Effect of the Invention) In the camshaft locating plate lubrication structure of the present invention, the lubricating oil has the first oil groove and the second oil groove formed on the thrust surfaces on both sides of the camshaft locating plate. Since it is possible to flow around the locating plate with a small flow resistance, it is possible to sufficiently lubricate the thrust surface, and it is possible to prevent engine trouble due to abnormal wear of the thrust surface.

[Brief description of drawings]

1 to 4 show a lubricating structure of a camshaft locating plate according to an embodiment of the present invention.
The figures are longitudinal sectional views showing the end of the camshaft together with a part of the cylinder head, and FIGS. 2 and 3 are rear and front views of the camshaft locating plate shown in FIG. 1, respectively, and FIG. Is a cross-sectional view showing a displacement state with respect to the camshaft locating plate, FIG. 5 and FIG.
FIG. 5 shows a conventional example, FIG. 5 is a longitudinal sectional view corresponding to FIG. 1, and FIG. 6 is a front view of the camshaft locating plate shown in FIG. 1 ... Camshaft, 2 ... Cylinder head 3 ... Bearing hole, 5 ... Oil supply hole 6 ... Passage, 7 ... Bearing gap 9 ... Sprocket 22 ... Camshaft locating plate 22a, 22b ... Thrust Surfaces 23a, 23b ... First oil groove 24a, 24b ... Second oil groove 25 ... Gap

Claims (1)

[Scope of utility model registration request] 1. A cylinder head for bearing-supporting a cam shaft, which is fixed to a part of a cylinder head opposed to a bearing gap supplied from the inside of the cam shaft, and the bearing support portion of the cam shaft and an axial direction thereof. A lubrication structure for a camshaft locating plate that is interposed between locking portions provided at appropriate intervals to fix the axial position of the camshaft, and the bearing support of the camshaft locating plate. A first oil groove that communicates with the bearing gap and is isolated from the outside is provided on the thrust surface facing the bearing portion, and at least a part of the second oil groove communicates with the outside on the thrust surface facing the locking portion. The groove is provided, and the first
The oil groove and the second oil groove are provided to face each other in a pair of upper and lower diametrical directions, and the first oil groove and the second oil groove are formed on the inner peripheral surface of the camshaft locating plate and the camshaft. Passages that are communicated with each other through a gap between the outer peripheral surface and the bearing gap and reach the outside through the first oil groove, the gap between the camshaft locating plate and the camshaft, and the second oil groove. The flow resistance of the lubricating oil passing through is set to be substantially equal to the flow resistance of the lubricating oil flowing from the bearing gap to the opposite side of the camshaft locating plate.