JPH06330719A - Lubricator of internal combustion engine - Google Patents

Abstract

PURPOSE:To reduce the amount of lubricant while appropriately carrying out lubrication by having the groove in the bearing part in the side of guiding the lubricant and the oil path of a cam shaft communicated with one another in an oil hole at a timing at which the bearing part which is remotest from the bearing part in the side of guiding the lubricant receives valve lifting reaction. CONSTITUTION:After the lubricant oil from an oil gallery 17 is guided into one bearing part 11 in a cam shaft 10 of an internal combustion engine, the oil is guided out to the other bearing part through an oil path 19 in the cam shaft 10. A groove 18 is formed into semicircle in the inner surface 16 of the bearing part in the side into which the lubricant is guided. On the other hand, an oil hole 20 for communicating the oil path 19 to the groove 18 is formed on the can shaft 10. The groove18 and the oil path 19 are communicated together in the oil hole 20 at a timing at which the bearing part that is remotest from the bearing part 11 in the side into which the lubricant oil is guided receives valve lifting reaction. The amount of the lubricant is reduced while each lubricating part is appropriately lubricated, to reduce the size of an oil pump.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating device for a cam bearing portion of an internal combustion engine.

[0002]

2. Description of the Related Art A camshaft for driving intake and exhaust valves of an internal combustion engine is supported by a plurality of bearings provided on a cylinder head. These bearing portions are composed of a split bearing portion and a bearing cap that are integral with the cylinder head, and the lubrication of each bearing portion is performed by lubricating oil from an oil gallery formed on the cylinder head.

In this case, the oil gallery 1 as shown in FIG.
Is penetrated through the cylinder head 2 and opened to the bearing surface 4 of one of the plurality of bearing portions 3 so that the lubricating oil is introduced from the oil gallery 1 to the one bearing portion 3 and the bearing surface 4
The lubricating oil is sent from the groove 5 formed on the entire circumference to the other bearing portion through the oil passage 7 in the cam shaft 6 that is in constant communication with the groove 5 (actually, the actual opening 61- 1
9607, 63-121707, etc.).

[0004]

However, in such a lubricating device, the pressure of the lubricating oil is the lubricating oil from the oil gallery 1 as shown in FIG. 6 due to the consumption of the lubricating oil in each bearing portion. The bearing portion farther from the bearing portion 3 on the introduction side becomes lower. For this reason, in order to maintain the required hydraulic pressure in the bearing portion farthest from the bearing portion 3 on the lubricating oil introduction side and perform good lubrication, the hydraulic pressure supplied from the oil gallery 1 is increased accordingly.

Therefore, the other bearings are supplied with oil pressure and oil amount more than required, and the capacity of the oil pump becomes larger than necessary, resulting in friction, deterioration of fuel consumption, and weight increase. I was invited.

The present invention aims to solve such problems.

[0007]

According to the present invention, lubricating oil from an oil gallery is introduced into one bearing portion of a camshaft and is supplied from the bearing portion to another bearing portion through an oil passage in the camshaft. In an internal combustion engine, a groove is formed on the inner surface of the bearing portion on the lubricating oil introduction side in a semicircle, and the camshaft has an oil passage in the camshaft in the groove, and the bearing portion farthest from the bearing portion provides the valve lift reaction force. Provide an oil hole that communicates at the receiving timing.

[0008]

The lubricating oil introduced from the oil gallery to one bearing portion of the camshaft communicates with the semicircular groove formed on the inner surface of the bearing portion through the oil passage of the camshaft through the oil passage of the camshaft. In the meantime, that is, at the timing at which the bearing portion farthest from the bearing portion receives the valve lift reaction force, it is supplied to other bearing portions including the farthest bearing portion.

As a result, while the respective bearings are being lubricated, the farthest bearing having a low lubricating oil pressure can be lubricated at an optimum time, and the supply of the lubricating oil is interrupted at other times. The amount of oil supplied from the oil gallery can be reduced.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, 10 is a cam shaft, and 11 is one of a plurality of bearing portions for supporting the cam shaft 10.

The bearing portion 11 is arranged on the engine front end side of the cylinder head 12 or the like.

This bearing portion 11, like other bearing portions (not shown), has a split bearing portion 13 provided integrally with the cylinder head 12, and the split bearing portion 13 has a bolt 1
It is formed from a bearing cap 15 fixed via 4.

An oil gallery 17 is provided on a bearing surface 16 of the bearing portion 11, a cylinder head 12, and a split bearing portion 13.
Also, a groove 18 is formed so as to penetrate through the mounting surface of the bearing cap 15 and a half circumference groove 18 is formed on the bearing cap 15 side and communicates with the opening.

On the other hand, an oil passage 19 is formed in the camshaft 10 toward another bearing portion (not shown), and an oil hole 20 is formed to connect the oil passage 19 to the groove 18 of the bearing portion 11. .

This oil hole 20 is provided at the timing when the bearing portion farthest from the bearing portion 11 receives the valve lift reaction force, that is, the cam 22 which is closest to the farthest bearing portion 21 as shown in FIGS. The valve 24 is formed so as to communicate with the groove 18 while the reaction force of opening the valve 24 against the valve spring 23 is applied to the bearing 21.

Outlet holes (not shown) are formed in the camshaft 10 for opening the oil passages 19 in the camshaft 10 to these bearing surfaces in each bearing except the bearing 11.

The oil gallery 17 is supplied with lubricating oil of a predetermined pressure from an oil pump (not shown).

Due to such a constitution, the oil gallery 1
The lubricating oil from 7 is introduced into the bearing portion 11 and
Is lubricated, and while the oil hole 20 of the camshaft 10 communicates with the half-circumferential groove 18 formed on the bearing surface 16, the oil passage 20 extends from the oil hole 20 to the oil passage 19 inside the camshaft 10 and an outflow hole (not shown). Is supplied to each bearing portion via.

In this case, the pressure of the lubricating oil becomes low in the bearing portion 21 farthest from the bearing portion 11, but the bearing portion 21
Since the lubricating oil is supplied during the period when the valve lift reaction force is received, that is, during the period when lubrication is particularly important, the lubrication is efficiently performed.

On the other hand, the lubrication of the other bearing portions other than the bearing portion 21 is also satisfactorily performed. That is, when the oil hole 20 of the camshaft 10 is not in communication with the groove 18, the supply of the lubricating oil to these bearings is interrupted, but the oil pressure and the amount of oil in these bearings are originally large. Therefore, sufficient lubrication can be obtained.

As a result, the amount of oil supplied from the oil gallery 17 can be reduced, the capacity of the oil pump can be reduced, the friction and weight of the pump can be reduced, and the fuel consumption of the engine can be improved.

FIG. 4 shows the refueling timing when the present invention is applied to a V-type DOHC 6-cylinder engine. In this case, the oil gallery is applied to the bearings of the # 1 and # 2 cylinders on both the intake valve side and the exhaust valve side. At the timing (# 5, # 6 cylinder valve timing) where the bearings on the # 5 and # 6 cylinder side farthest from the cylinder receive the valve lift reaction force while introducing the lubricating oil, # 3 to # 6 Lubricating oil is supplied to the bearing portion on the cylinder side. It can be seen from this that the amount of lubricating oil supplied from the oil gallery can be reduced.

[0024]

As described above, according to the present invention, the lubricating oil from the oil gallery is introduced into one bearing portion of the camshaft and is supplied from the bearing portion to another bearing portion through the oil passage in the camshaft. In an internal combustion engine, a groove is formed on the inner surface of the bearing portion on the lubricating oil introduction side in a semicircle, and the oil passage in the camshaft is formed in the groove in the camshaft, and the bearing portion farthest from the bearing portion provides the valve lift reaction force. Since the oil holes that communicate at the timing of receiving the oil are provided, the amount of lubricating oil can be reduced while accurately lubricating each bearing, and the oil pump can be made smaller to reduce friction and weight, and improve engine fuel efficiency. To do.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a main part of an embodiment.

FIG. 2 is a side view showing a valve opening movement of a cam.

FIG. 3 is a characteristic diagram of refueling timing.

FIG. 4 is a characteristic diagram of refueling timing when applied to a V-type DOHC 6-cylinder engine.

FIG. 5 is a partial configuration diagram of a conventional example.

FIG. 6 is a characteristic diagram showing a pressure drop of lubricating oil.

[Explanation of symbols]

 10 cam shaft 11 bearing part 12 cylinder head 13 split bearing part 15 bearing cap 16 bearing surface 17 oil gallery 18 half-circumferential groove 19 oil passage 20 oil hole 21 bearing part

Claims (1)

[Claims] 1. An internal combustion engine in which lubricating oil from an oil gallery is introduced into one bearing portion of a camshaft and is supplied from the bearing portion to another bearing portion through an oil passage in the camshaft. A groove is formed on the inner surface of the bearing part of the camshaft, and an oil hole is formed in the camshaft so that the oil passage in the camshaft communicates with the groove at the timing when the bearing part farthest from the bearing part receives the valve lift reaction force. A lubricating device for an internal combustion engine, characterized by being provided with.