JPH0619775Y2 - Lubrication device for valve train - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a lubricating device for an internal combustion engine having a direct valve operating system, and in particular, forcibly lubricates a contact surface of an intake / exhaust valve of a valve lifter with a valve stem. The lubrication device.

[Conventional technology]

As prior arts related to the present invention, Japanese Utility Model Publication No. 33-1504, Japanese Utility Model Publication No. 58-130004, Japanese Utility Model Publication No. 60-164611, Japanese Utility Model Publication No. 60-170010, and Japanese Utility Model Publication No. 62-21411. The publication is known.

The lubrication device for a valve mechanism disclosed in Japanese Utility Model Publication No. 33-1504 described above is applied to a horizontal engine, in which lubricating oil is dripped and scattered from above the valve spring, It lubricates the essential parts.

In the device disclosed in Japanese Utility Model Laid-Open No. 58-130004, a valve lifter (tappet) is divided into an inner tappet that contacts the stem end of the valve and an outer tappet that directly contacts the cam, and is formed on the outer tappet side. The oil supplied from the oil introduction port is supplied to the contact surface of the stem end of the valve via an oil chamber formed between the inner tappet and the outer tappet.

The device disclosed in Japanese Utility Model Publication No. 60-164611 has an oil hole formed in a shim provided on the top surface of a valve lifter, and oil is supplied to the upper end surface of the stem of the valve through the oil hole. It was done.

In the device disclosed in Japanese Utility Model Laid-Open No. 60-170010, a groove extending in the circumferential direction is formed on the sliding surface of a valve lifter, and an oil hole is made to penetrate from the groove to the inner peripheral surface. Oil is supplied to the upper end surface of the stem of the valve.

In the lubrication device disclosed in Japanese Utility Model Laid-Open No. 62-21411, a taper portion is formed inside the valve lifter, with the apex at which the tip of the valve stem abuts.

[Problems to be solved by the invention]

Since ceramics are lightweight and have excellent heat resistance, it is possible to reduce the weight of the intake / exhaust valve and improve its heat resistance by constructing the intake / exhaust valve from ceramics, which significantly improves engine performance. it can.

However, if the intake / exhaust valve is made of ceramic, the contact portion of the inner surface of the valve lifter with the valve stem end is significantly worn, and the timing is deviated. That is, although the valve lifter is hardened by the heat treatment, the hardness of the ceramic is significantly higher than the hardness of the valve lifter, and therefore the wear of the valve lifter becomes significantly large if the lubrication is insufficient. Therefore, when a ceramic intake / exhaust valve is used, the adjusting shim must be frequently adjusted.

For example, Japanese Utility Model Publication No. 60-164611 and Japanese Utility Model Publication No.
With the lubrication structure as disclosed in Japanese Patent No. 170010, there is no problem when the valve is made of metal, but when the valve is made of ceramic, lubrication becomes insufficient. In other words, the actual Kaisho 60-164611
In the lubrication structure like Japanese Patent Publication, since the cam surface is always in close contact with the shim, it is difficult for oil to enter the oil hole of the shim,
The contact surface between the valve lifter and the upper end surface of the valve stem cannot be sufficiently lubricated. Further, in the lubrication structure as disclosed in Japanese Utility Model Laid-Open No. 60-170010, there is no means for guiding the oil from the oil hole penetrating the sliding surface of the valve lifter to the upper end surface of the valve stem. The contact surface of the valve with the upper end surface of the stem cannot be sufficiently lubricated.

Further, since the valve lifter is repeatedly subjected to compressive load, its strength must be sufficient.
There are problems with the structures disclosed in Japanese Patent Publication No. 62-21411 and Japanese Utility Model Publication No. 62-21411. That is, in the device of Japanese Utility Model Laid-Open No. 58-130004, since the valve lifter is divided into two and the oil chamber is formed in the valve lifter, the reliability with respect to the compressive load is lacked and the valve lifter may be deformed. Furthermore, in the device of Japanese Utility Model Laid-Open No. 62-21411, since a plurality of oil holes penetrating the inner surface of the valve lifter are formed in the recess of the valve lifter into which the shim is fitted, the strength against a compressive load is similarly reduced, There is a problem of reduced reliability.

The present invention focuses on the above problems, and provides a lubrication device for a valve train that can sufficiently lubricate the contact surface between the valve lifter and the upper end surface of the valve stem without lowering the strength of the valve lifter. With the goal.

[Means for solving problems]

A lubricating system for a valve system according to the present invention which meets this object is a valve operating system for an internal combustion engine in which an upper end surface of a valve stem of an intake / exhaust valve is in contact with a top portion of an inner surface of a valve lifter slidably fitted to a cylinder head. In the system, in the cylinder head,
An oil that forms an oil passage that opens on a sliding surface with the valve lifter, and has a recessed portion at a position on the outer peripheral surface of the valve lifter that can face the opening of the oil passage and that stores the oil supplied from the oil passage. A reservoir is formed, and the valve lifter is provided with an oil hole, one of which opens in a depressed portion of the oil reservoir and the other of which opens in a contact surface with which the top of the valve stem abuts.

[Action]

In the valve operating system lubrication device thus configured, oil is supplied to the outer peripheral surface of the valve lifter from the oil passage formed in the cylinder head. Since the oil sump is formed on the outer peripheral surface of the valve lifter, most of the oil supplied to the outer peripheral surface is stored in the oil sump. That is, in the case where the groove is simply formed on the outer peripheral surface of the valve lifter as in the conventional structure, even if the oil is supplied to the groove, the oil is not sufficiently collected in the groove and the oil flows out along the outer peripheral surface. By forming the oil reservoir having the portion, most of the oil supplied from the cylinder head side can be reliably retained. Further, as the valve lifter rises, the oil adhering to the sliding surface is scraped up and the oil flows into the oil sump.

The oil stored in the oil sump is supplied to the contact surface of the valve stem of the intake / exhaust valve through the oil hole, and the contact surface between the valve lifter and the valve stem is sufficiently lubricated by the oil. Therefore, even if the intake / exhaust valve is made of ceramics, the wear of the valve lifter is greatly suppressed, and the valve timing adjustment by the adjusting shim becomes almost unnecessary.

In the present invention, the valve lifter has a two
Since no holes are formed to divide the valve lifter or to penetrate the valve lifter from above and below, sufficient strength against a compressive load can be maintained.

〔Example〕

Hereinafter, preferred embodiments of a valve train lubrication device according to the present invention will be described with reference to the drawings.

1 to 3 show an embodiment of the present invention. In the figure, 1 indicates a cylinder head, and 2 indicates a valve lifter formed in a cylindrical cup shape. The valve lifter 2 is slidably fitted in the valve lifter hole 3 of the cylinder head 1. A recess 2 is provided on the top surface of the valve lifter 2.
a is formed, and the adjusting shim 4 is fitted in the recess 2a. The cam surface 5 a of the cam shaft 5 is in contact with the adjusting shim 4. Inside the valve lifter 2, for example, the valve stem 6a of the intake valve 6 is located, and the top portion 6 of the valve stem 6a is located.
b is the top of the inner surface of the valve lifter 2, that is, the ceiling surface 2b
Is in contact with the side.

The valve stem 6a is supported by a valve stem guide 7 fixed to the cylinder head 1 side so as to be vertically slidable. A retainer 13 is attached via a cotter 8 near the upper end of the valve stem 6a. A valve spring 9 is interposed between the retainer 13 and the portion of the cylinder head 1 where the valve stem guide 7 is located.

One of the oil passages 10 formed in the cylinder head 1 is opened at the sliding surface 1 a of the cylinder head 1 with respect to the valve lifter 2. The other side of the oil passage 10 is connected to an oil pump (not shown) so that oil pumped up from the oil pan by the oil pump is supplied to the outer peripheral surface 2c of the valve lifter 2 via the oil passage 10.

Cylinder head 1 on outer peripheral surface 2c of valve lifter 2
Of the oil passage 10 on the side where it can face the opening of the oil passage 10.
A plurality of oil sumps 11 for accumulating the oil supplied from are formed. The oil sump 11 is, as shown in FIG.
It is arranged at a predetermined interval in the circumferential direction. Each oil sump 11 has a recess 11a, and the oil stored in this recess 11a is prevented from flowing out to the outer peripheral surface 2c by the wall 2d having an inclined surface on the inside.

Oil sump 11 formed on the outer peripheral surface 2c of the valve lifter 2
An oil hole 21 for guiding the oil in the oil reservoir 11 to the ceiling surface 2b side is formed between the ceiling surface 2b and the top surface 6b of the valve stem 6a. That is, one of the oil holes 21 is opened to the depressed portion 11a of the oil sump 11, and the other of the oil holes 21 is opened to the contact surface 2e of the ceiling surface 2b with which the top portion 6b of the valve stem 6a abuts. .

In the present embodiment, a plurality of oil sumps are formed on the outer peripheral surface of the valve lifter 2, but the oil sumps may have a groove shape that continuously extends in the circumferential direction.

Next, the operation of this embodiment will be described.

The oil pumped to the oil passage 10 by an oil pump (not shown) is ejected from the opening of the oil passage 10 toward the outer peripheral surface 2c of the valve lifter 2. As shown in FIG. 3, a plurality of oil sumps 11 are formed on the outer peripheral surface 2c of the valve lifter 2, so that most of the oil ejected from the oil passage 10 is accumulated in the oil sumps 11. Further, from the upper surface of the cylinder head 1, the valve lifter 2 and the valve lifter hole 3
A part of the oil that has flowed into the gap between and is accumulated in the oil sump 11 by raising the valve lifter 2.

The oil sump 11 is not just a groove as in the past, but a recess 11
Since it has a, the oil from the oil passage 10 is surely stored in the recess 11a and does not flow back to the outer peripheral surface 2c, and the oil stored in the recess 11a passes through the oil hole 12 to the ceiling. The valve stem 6a of the surface 2b is guided to the contact surface 2e with which the valve stem 6a contacts.

As a result, the contact surface 2e of the valve lifter 2 is sufficiently supplied with oil, and even if the intake / exhaust valve is made of high hardness ceramic, the contact surface 2e of the valve lifter 2 is worn more than the conventional lubricating structure. Is greatly suppressed.

[Effect of device]

According to the lubrication device for a valve system of the present invention, the cylinder head is provided with an oil passage opening to the sliding surface with the valve lifter, and the recessed portion is formed on the outer peripheral surface of the valve lifter at a position facing the opening of the oil passage. Has an oil reservoir for storing the oil supplied from the oil passage, and the valve lifter is provided with an oil hole, one of which opens in the depression of the oil reservoir and the other of which opens in the contact surface with which the top of the valve stem abuts. With this configuration, oil can be reliably supplied to the contact portion between the valve lifter and the valve stem.

Further, since the oil from the oil passage and the oil lifted up by the valve lifter can be stored in the oil sump, more oil can be supplied to the contact portion between the valve lifter and the valve stem than in the conventional device. Therefore,
Even when the intake / exhaust valve is made of a ceramic having a high hardness, the wear of the valve lifter can be suppressed to a very small level, and the valve timing adjustment by the adjusting shim becomes almost unnecessary.

According to the present invention, unlike the conventional structure, the valve lifter is not divided into two, and the holes penetrating the valve lifter up and down are not formed, so that the strength against a compressive load can be sufficiently maintained.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of a lubricating device for a valve train according to an embodiment of the present invention, FIG. 2 is a partially enlarged sectional view of the device shown in FIG. 1, and FIG. 3 is a valve lifter in the device shown in FIG. Is a front view of FIG. 1 ...... Cylinder head 2 ...... Valve lifter 2b ...... Ceiling surface 2e ...... Contact surface 6 ...... Intake valve 6a ...... Valve stem 10 ...... Oil passage 11 ...... Oil sump 11a ...... Cavity 21 ... Oil hole

Claims (1)

[Scope of utility model registration request] 1. In a valve train of an internal combustion engine in which an upper end surface of a valve stem of an intake / exhaust valve is in contact with a top portion of an inner surface of a valve lifter slidably fitted in a cylinder head, the cylinder head is provided with a valve lifter. An oil passage having an opening in the sliding surface is formed, and an oil reservoir having a depression is formed at a position on the outer peripheral surface of the valve lifter that can face the opening of the oil passage, and stores oil supplied from the oil passage. The valve lifter is provided with an oil hole, one of which is opened in a depressed portion of the oil sump and the other of which is opened in a contact surface with which the top of the valve stem abuts.