JP2510713Y2 - Engine lubricator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an engine lubrication device having a valve mechanism including a variable valve timing mechanism and a lash adjuster.

(Prior Art) Conventionally, in a valve operating mechanism of an engine, a variable valve timing mechanism is attached to a drive mechanism of a camshaft that opens and closes an intake / exhaust valve, and a rotation phase of a crankshaft and a camshaft is changed to exhaust valve Alternatively, a technique in which the valve timing of the intake valve is changed in accordance with the operating state is known, for example, as disclosed in Japanese Utility Model Laid-Open No. 62-57711.

The variable valve timing mechanism of the above-mentioned prior art is operated by hydraulic pressure supply, and its operation control is performed by installing an electromagnetic actuator in the oil outflow portion of the camshaft provided with the variable valve timing mechanism. .

In addition, a lash adjuster (HLA) that automatically adjusts the valve clearance is also installed,
Normally, oil is supplied to the lash adjuster from the cam journal oil passage in the cylinder head.

(Problems to be solved by the invention) However, as described above, in the engine equipped with the variable valve timing mechanism and the lash adjuster, when supplying the working oil for both, ensuring the hydraulic pressure on the cylinder block side and eliminating the need for the cylinder head portion. If an orifice is provided between the cylinder block and cylinder head to adjust the oil supply amount and oil pressure to the cylinder head side in order to reduce the end flow oil, it is difficult to ensure good operation of both. There is a risk that

That is, in order to secure a certain amount of oil pressure on the cylinder block side, it is necessary to limit the amount of oil to the cylinder head side to some extent from the balance between the two, but in an area where the engine speed is low and the generated oil pressure is low, such as during idling, When the oil temperature is high, or when the engine is started after being left for a long time, the operating oil pressure is low due to insufficient oil supply to the lash adjuster.
It takes time to discharge the air mixed in the lash adjuster, which causes abnormal noise.

In order to prevent the generation of this abnormal noise, it is sufficient to introduce high hydraulic pressure to the lash adjuster and expel mixed air in a short period of time, but high pressure oil is also supplied to the cam journal part and end flow oil is generated. It is necessary to increase the oil pump capacity and increase the oil pump capacity, and originally, such a high hydraulic pressure is unnecessary for the cam journal portion.

In view of the above circumstances, the present invention has an object to provide an engine lubrication device that appropriately supplies oil to each of the variable valve timing mechanism, the lash adjuster, and the camcill journal. Is.

(Means for Solving the Problems) In order to achieve the above object, an engine lubrication device of the present invention is provided with a cam journal oil passage communicating with a main oil passage through a throttle portion and a cam journal oil passage. A control valve for controlling the operation of the variable valve timing mechanism is provided in the oil supply passage by branching from the main oil passage upstream of the throttle portion to the hydraulically operated variable valve timing mechanism to supply oil. And an oil passage for the lash adjuster, which branches from the oil supply passage upstream of the control valve and supplies oil to the lash adjuster.

Further, it is preferable that the control valve is configured to close the oil supply passage when the engine speed is low.

(Operation) In the lubricating device as described above, the low pressure side oil is supplied to the cam journal part from the main oil passage through the throttle part and the cam journal oil passage to reduce the end flow oil amount, In addition, the variable valve timing mechanism and the lash adjuster are supplied with high oil pressure without increasing the capacity of the oil pump to obtain good operation of both, and the rush adjuster improves the generation of abnormal noise by the early discharge of air. I am trying to do it. On the other hand, when the control valve of the variable valve timing mechanism closes the oil supply passage when the engine speed is low, it is possible to supply the necessary oil to the lash adjuster that requires high oil pressure at low speed.

(Embodiment) Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First
The figure shows a schematic structure of an engine lubrication structure of one embodiment,
FIG. 2 shows a cross-sectional structure of the main part of the cylinder head portion, and FIG. 3 shows a schematic plan structure of the cylinder head.

The cylinder head 2 of the engine 1 has an intake-side cam journal portion 5 that supports the intake-side camshaft 3 and an exhaust-side cam journal portion 6 that supports the exhaust-side camshaft 4. Further, the intake port 7 and the exhaust port 8
The intake valve 9 and the exhaust valve 10 for opening and closing the lash adjuster 12 that automatically adjusts the valve clearance by the cam portions 3a, 4a of the intake-side or exhaust-side camshafts 3, 4 described above.
It is opened and closed via. In addition, the exhaust side camshaft 4
A variable valve timing mechanism 13 that changes the rotational phase of the hydraulically actuated camshaft 4 is installed at the end of the.

In the oil passage structure of FIG. 1, a main oil passage 15 is formed in the cylinder head 2 to which the oil pressurized by an oil pump on the cylinder block side (not shown) is fed.

An oil passage 17 for the cam journal is communicated with the intake-side cam journal portion 5 and the exhaust-side cam journal portion 6 from the main oil passage 15 through the throttle portion 16 (orifice), and the metering portion 16 adjusts the amount. The low-pressure side oil thus supplied is supplied to lubricate and cool the cam journal portions 5, 6.

An oil supply passage 18 is provided so as to branch from the main oil passage 15 upstream of the throttle portion 16.
Is introduced into the exhaust side camshaft 4 to supply the high pressure side oil to the variable valve timing mechanism 13. And the variable valve timing mechanism
In the middle of the oil supply path 18 to the 13
A control valve 21 for opening and closing the valve is provided, and the valve timing switching control by the variable valve timing mechanism 13 is performed by the operation of the control valve 21.

Further, an oil passage 19 for the lash adjuster is provided branching from the oil supply passage 18 upstream of the control valve 21, and the oil passage 19 for the lash adjuster is provided for the intake valve 9 and the exhaust valve 10 of each cylinder. The lash adjuster 12 is connected to the lash adjuster 12 and is configured to supply oil on the high pressure side.

A concrete structure of the variable valve timing mechanism 13 will be briefly described with reference to FIG. 1. An end portion of the exhaust side camshaft 4 is fitted into a cylindrical case 25, and a driving force is transmitted to an outer periphery of the case 25. Rings 26 are connected. Further, a cylindrical spacer 27 is attached to the tip of the exhaust side camshaft 4 by a fixing bolt.
It is fixed integrally by 29. A ring-shaped piston 30 is installed inside the case 25 with the spacer 27, and helical splines 32 and 33 in opposite directions are formed inside and outside the piston 30, respectively.
7 and the case 25 are spline-fitted. The piston 30 is biased toward the tip side by a spring 36.

On the other hand, the exhaust-side camshaft 4 has an oil passage 37 formed along the axis thereof, and the fixing bolt 29 has a through hole 38 communicating with the oil passage 37. A pressure chamber 41, which faces the head of the piston 30 and guides the oil pressure from the oil passage 37, is provided inside the tip of the case 25. Then, in response to the operation of the control valve 21, hydraulic pressure is introduced into these pressure chambers 41 through the oil supply passage 18 and the oil passage 37, compressing the spring 36 and moving the piston 30 in the axial direction, One of the spacer 27 and the case 25 fitted with the helical splines 32, 33 formed in the inner circumference and the outer circumference of the piston 30 in the opposite direction rotates relative to the other. As a result, the phase between the exhaust side camshaft 4 integrated with the spacer 27 and the driving force transmission wheel 26, that is, the valve timing is changed.

The above valve timing is engine speed 1500-2000
The control valve 21 is opened at a speed of about rpm to introduce high hydraulic pressure to increase the overlap of the intake / exhaust valve and reduce the overlap in the low rotation region.

On the other hand, a structural example of the lash adjuster 12 is, as shown in FIG.
And a plunger 46 is installed in the body 45 with its tip abutting against the heads of the intake and exhaust valves 9 and 10.
Hydraulic pressure is introduced into the high-pressure chamber inside via a check ball 48. Further, a plunger spring 49 is provided in the high pressure chamber, and when the valve is opened, the check ball 48 is closed and the intake / exhaust valve 9,
When 10 is pushed down, when the valve is opened, the check ball 48 opens according to the pressure drop in the high pressure chamber, and the oil flows in, so that the valve clearance is always automatically adjusted to 0.

A second oil passage is formed in the cylinder head 2.
More specifically, referring to FIG. 3 and FIG. 3, on the upper surface of the cylinder head 2, a plug hole is formed substantially at the center corresponding to each cylinder.
51 is formed, and each cylinder is provided with an intake valve hole 52 in which two intake valves 9 and a lash adjuster 12 are installed, and an exhaust valve hole 53 in which two exhaust valves 10 and a lash adjuster 12 are installed. ing.

Further, the intake side and exhaust side camshafts 3 and 4 are mounted on the upper surface of the cylinder head 2.
The cylinder head 2 has a cam journal portion for supporting both end portions and intermediate portions of the cam shafts 3 and 4, respectively.
5 and 6 are provided.

The inflow of oil from the cylinder block is carried out at a substantially central lower surface near one side of the cylinder head 2.
A main oil passage 15 is formed obliquely from 15a toward the center of the upper surface. The main oil passage 15 communicates with an oil chamber 54 formed in the upper surface of the cylinder head 2. The upper surface of the oil chamber 54 is closed with a plug.

The cylinder head 2 is provided on both sides of the oil chamber 54.
Along the longitudinal direction of the, the cam journal oil passage 17 for supplying oil to the cam journal portions 5 and 6 is provided at the upper portion, and the oil supply passage 18 for supplying oil to the variable valve timing mechanism 13 and the lash adjuster 12 is provided at the lower portion, Has been formed. The cam journal oil passage 17 communicates with the oil chamber 54 through a communication passage 17a having a throttle (not shown), and the cam journal oil passage 17 communicates with the main oil passage 15. ing. Similarly, the oil supply passage 18 is also connected to the oil chamber 5 via the communication passage 18a.
The short oil passage 19 for the lash adjuster communicates with the valve holes 52, 53 from the oil supply passage 18, and supplies the high pressure oil to the lash adjuster 12 fitted in the valve holes 52, 53. Is configured to.

A control valve mounting portion 55 is formed at the exhaust side end of the cylinder head 2, and the oil supply passage 18 communicates with the control valve mounting portion 55 at a portion downstream of the branch portion of the rush adjuster oil passage 19. An oil supply passage 18 passing through the control valve 21 communicates with an oil passage 37 in the exhaust side camshaft 4 and passes through a central portion of the exhaust side camshaft 4 to a variable valve timing mechanism 13 attached to the other end. Sent.

According to the embodiment as described above, the cam journal portions 5 and 6 supporting the cam shafts 3 and 4 do not need to supply high hydraulic pressure, and the oil pressure adjusted from the main oil passage 15 to the low pressure via the throttle portion 16 is reduced. Is supplied by the cam journal oil passage 17, the end flow oil amount can be reduced, and the supply pressure to other oil passages can be increased. Also,
Variable valve timing mechanism 13 and lash adjuster
It is necessary to supply a high hydraulic pressure to 12, and it is possible to obtain a high hydraulic pressure by supplying a high hydraulic pressure through an oil supply passage 18 branched from the upstream of the throttle portion 16 without increasing the capacity of the oil pump. it can.

On the other hand, the control valve 21 of the variable valve timing mechanism 13 is configured to close the oil supply passage 18 when the engine speed is low, and at this low speed, the rotation speed of the oil pump is low and the generated hydraulic pressure is insufficient. By supplying oil to the adjuster 12 in a concentrated manner, it is possible to supply high hydraulic pressure even at low rotation speed and ensure the operation of the lash adjuster 12.

(Effect of the Invention) According to the present invention as described above, the low pressure side oil is supplied to the cam journal portion from the main oil passage through the oil passage for the cam journal from the main oil passage through the throttle portion. In addition, the variable valve timing mechanism and the lash adjuster are supplied with high oil pressure without increasing the capacity of the oil pump to obtain good operation of both, and the lash adjuster is different due to the early discharge of air. The generation of sound can be improved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an engine lubricating device according to an embodiment of the present invention, FIG. 2 is a sectional view of a cylinder head portion, and FIG. 3 is a plan view of the cylinder head. 1 ... Engine, 2 ... Cylinder head, 3,4 ... Cam shaft, 5,6 ... Cam journal part, 12 ... Rush adjuster, 13 ... Variable valve timing mechanism, 15 ...
Main oil passage, 16 ... throttle part, 17 ... oil passage for cam journal, 18 ... oil supply passage, 19 ... oil passage for lash adjuster, 21 ... control valve, 54 ... oil chamber.

Claims (2)

(57) [Scope of utility model registration request] 1. A variable valve timing mechanism for hydraulically changing the rotational phase of a camshaft is attached to a camshaft of a valve mechanism, and a main oil passage and a throttle portion are provided in a cam journal portion supporting the camshaft. An oil passage for a cam journal communicating therewith, and an oil supply passage branched from a main oil passage upstream of the throttle portion to supply oil to the variable valve timing mechanism, and the variable valve is provided in the oil supply passage. A lubricating device for an engine, comprising: a control valve for controlling the operation of a timing mechanism; and an oil passage for a lash adjuster, which branches from an oil supply passage upstream of the control valve and supplies oil to the lash adjuster. 2. The engine lubrication device according to claim 1, wherein the control valve closes the oil supply passage when the engine is running at a low speed.