JP3170175B2 - Lubricating device for camshaft gear in DOHC type internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a DOHC type internal combustion engine having a camshaft for an intake valve and a camshaft for an exhaust valve on the upper surface of a cylinder head. The present invention relates to a device for supplying lubricating oil to a pair of gears for transmitting rotation of a camshaft to another camshaft.

[0002]

2. Description of the Related Art In a recent DOHC type, rotation of a crankshaft is transmitted to one of two camshafts disposed on the upper surface of a cylinder head via a timing belt or a chain. The rotation of one camshaft
The transmission is performed on the other camshaft via a pair of gears fitted on the two camshafts so as to mesh with each other.

In this case, Japanese Utility Model Application Publication No.
Japanese Patent Publication No. 125617 discloses a device for supplying lubricating oil to the pair of gears, in which lubricating oil from a lubricating oil pump in an internal combustion engine is bored inside the one camshaft or the other camshaft. It has been proposed to supply the lubricating oil to the pair of gears after introducing the lubricating oil into the lubricating oil passage.

[0004]

However, this prior art lubricating device supplies a part of the lubricating oil discharged from a lubricating oil pump in an internal combustion engine to a pair of gears between the two camshafts. Due to this, the discharge amount of the lubricating oil in the lubricating oil pump must be increased by the amount of supplying a part of the lubricating oil discharged from the lubricating oil pump to the pair of gears, In other words, since the lubricating oil pump must be enlarged accordingly, lubrication of the pair of gears not only increases the mechanical loss of output in the internal combustion engine, but also increases the size of the lubricating oil pump, There is a problem that the entire internal combustion engine including the lubricating oil pump is increased in size.

An object of the present invention is to solve the above problem by lubricating the pair of gears using lubricating oil after lubricating a bearing at one end of a camshaft. It is.

[0006]

SUMMARY OF THE INVENTION To achieve this technical object, the present invention relates to a method of manufacturing a camshaft for an intake valve and a camshaft for an exhaust valve, which are provided on the upper surface of a cylinder head. A bearing seat integrally provided on the cylinder head side so as to have a bearing hole, and a bearing portion comprising a bearing cap body fastened to the bearing seat and provided with a semi-circular bearing hole on the lower surface, are pivotally supported, In the DOHC type internal combustion engine, a lubricating oil supply passage is provided in the bearing portion, and gears meshing with each other are fitted to respective portions of the two camshafts adjacent to the bearing seat. A lubricating oil reservoir is provided outside the one semi-circular bearing hole in the bearing seat, and an oil passage is formed such that one end of the oil passage is open in the lubricating oil reservoir and the other end is a side surface of the one gear. To It was constructed to say that bored so as to be opened. "Te.

[0007]

[Operation] In this configuration, the lubricating oil supplied to the bearing portion lubricates the bearing portion, and then accumulates in a lubricating oil reservoir recess provided outside the bearing portion. It is sequentially supplied to the side surface of one of the gears through the oil passage. That is, it is possible to sequentially lubricate a pair of gears between the two camshafts and a lubricating oil after lubricating a bearing portion for one of the camshafts.

[0008]

As described above, according to the present invention, a pair of gears between two camshafts can be lubricated with lubricating oil after lubricating a bearing portion for one camshaft. As compared with the case where a part of the lubricating oil from the lubricating oil pump in the internal combustion engine is supplied to the pair of gears, the discharge amount of the lubricating oil pump can be reduced by that much. This has the effect of reducing the mechanical loss and reducing the size of the lubricating oil pump, and the size of the entire internal combustion engine including the lubricating oil pump.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In this figure, reference numeral 1 denotes a cylinder block, and reference numeral 2 denotes a cylinder head fastened to the upper surface of the cylinder block 1 by a plurality of head bolts (not shown).

Reference numeral 5 denotes a camshaft for the intake valve 6, and reference numeral 7 denotes a camshaft for the exhaust valve 8. Both camshafts 5 and 7 are provided in the valve mechanism chamber 2a on the upper surface of the cylinder head 2. And is supported in parallel by the intermediate bearings 4a and 4b at the portion between the cylinders and the bearing 3 at one end. The two camshafts 5 and 7 are configured to rotate in conjunction with each other by gears 8 and 9 disposed so as to mesh with each other inside the bearing portion 3, while the two camshafts 5 and 7 are rotated. A timing pulley 10 is fitted to a shaft end of one of the camshafts 7 protruding outward from the bearing portion 3, and a timing belt 11 from a crankshaft (not shown) is wound around the timing pulley 10. By hanging, one camshaft 7
The camshaft 7 is configured to transmit the rotation of the crankshaft and transmit the rotation from the one camshaft 7 to the other camshaft 5.

The bearing portion 3 includes a bearing seat 12 formed integrally with the cylinder head 2 and a bearing cap 13 disposed on an upper surface thereof.
2, a semicircular bearing hole 12a in which the lower half of the journal portion 5a of the intake valve camshaft 5 fits, and a semicircular bearing in which the lower half of the journal portion 7a of the exhaust valve camshaft 7 fits. On the lower surface of the bearing cap 13, a semi-circular bearing hole 13a in which the upper half of the journal portion 5a of the intake valve cam shaft 5 is fitted, and a journal portion 7a of the exhaust valve cam shaft 7 are provided. The bearing cap body 13 is provided with a semi-circular bearing hole 13b in which an upper half of the bearing is fitted.
It is configured to be fastened at 4, 15, and 16.

The journal portion 5 of the cam shaft 5 for the intake valve of the bearing seat 12 and the bearing cap 13 is provided.
semi-circular bearing hole 12a and semi-circular bearing hole 1 into which a fits
Bosses 12c, 13c are integrally provided on the outer portion of 3a so as to protrude outward.
13c, annular grooves 12c 'and 13c' in which the thrust receiving disk 5b provided in the intake valve camshaft 5 fits, and bearing holes 12 in which the shaft end 5c of the intake valve camshaft 5 fits.
c "and 13c".

Further, the cylinder head 2 communicates with a main lubricating oil passage (not shown) on the cylinder block 1 side, and lubricating oil from a lubricating oil pump (not shown) is supplied to the bearing seat 12 in both semicircles. Bearing hole 12
A lubricating oil supply passage 17 is formed so as to lead to a and 12b. The boss 12c of the bearing seat 12
In the inner surface of the bearing hole 12c "at the
While the bearing seat 12 is provided with an oil passage 19.
And one end of the oil passage 19 is connected to the lubricating oil reservoir recess 18.
And the other end is opened to the side of the gear 9 on the intake valve camshaft 5.

In this configuration, the lubricating oil from the lubricating oil pump is supplied to the journal 5a of the camshaft 5 for the intake valve and the journal 7a of the camshaft 7 for the exhaust valve via the lubricating oil supply passage 17. It is lubricated by doing. Journal part 5 of camshaft 5 for intake valve
A part of the lubricating oil after lubricating a accumulates in a lubricating oil reservoir recess 18 provided outside thereof, and then from the lubricating oil reservoir recess 18 through an oil passage 19, a camshaft for an intake valve. 5
Since it is sequentially supplied to the side of the gear 8 above,
The pair of gears 8, 9 between the camshafts 5, 7 can be lubricated.

In the above embodiment, the lubricating oil reservoir 18 and the oil passage 19 are provided on the bearing portion side with respect to the intake valve cam shaft 5. However, the present invention is not limited to this. It goes without saying that the lubricating oil storage recess 18 and the oil passage 19 may be provided on the bearing portion side with respect to the exhaust valve camshaft 7.

[Brief description of the drawings]

FIG. 1 is a plan view of a cylinder head showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is an enlarged sectional view taken along line IV-IV of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylinder block 2 Cylinder head 3 Bearing part 5 Camshaft for intake valve 7 Camshaft for exhaust valve 8, 9 Gear 10 Timing pulley 11 Timing belt 12 Bearing seat 13 Bearing cap body 18 Lubricant oil recess 19 Oil passage

Claims (1)

(57) [Claims] 1. A bearing seat in which ends of a cam shaft for an intake valve and a cam shaft for an exhaust valve disposed on an upper surface of a cylinder head are integrally provided on a cylinder head side so as to have a semi-circular bearing hole on an upper surface. And a bearing cap body which is fastened to the bearing seat and has a semi-circular bearing hole on the lower surface, and is supported by a bearing portion. A gear meshing with each other at each of the portions adjacent to the bearing seat.
In the OHC type internal combustion engine, a lubricating oil reservoir is provided on the bearing seat outside one of the semi-circular bearing holes in the bearing seat, and one end of the oil passage is provided in the lubricating oil reservoir. A lubricating device for a camshaft gear in a DOHC type internal combustion engine, wherein the lubricating device is formed so as to be open and the other end open to a side surface of the one gear.