JPH0343614A - Valve stem lubrication device for engine - Google Patents

Abstract

PURPOSE:To eliminate oil droppage to a suction/exhaust port at the time of high speed rotation while securing the quantity of lubrication oil at the time of low speed rotation by providing an oil pressure operated valve in a valve stem lubrication oil passage, lubricating forcedly at the time of low speed rotation of an engine, and lubricating with mist at the time of high speed rotation. CONSTITUTION:A valve stem lubrication oil passage 13 is formed inside a locker arm 10, an entrance 13a is faced with an oil passage 12 in a locker arm shaft 11, and an exit 13c is faced with a recess part 21 of a retainer 20 at a head part 6a of valve stem 6 respectively. In this case, an oil pressure operated valve 15 is put in the valve stem lubrication oil passage 13. The oil pressure operated valve 15 has a core 17 engaged in a core insetion hole 16, and it is energized to the valve opening side by a pressure regulation screw 19 through a valve opening spring 18. When the oil pressure in the valve stem lubrication oil passage 13 is low, the valve core 17 is moved to the valve opening side, while if the oil pressure is high, the valve core 17 is operated to the valve closing side againt the pressure regulation spring 18.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a valve shaft lubrication device for an engine, and particularly to one that prevents seizure of intake and exhaust valve shafts due to insufficient lubrication during low-speed operation.

[Conventional technology]

In general, as a valve shaft lubrication device, is oil the main strike? ll
There are types that slide, and types that form a valve shaft lubricating oil passage and pump lubricating oil.

When lubricating with oil main stroke, depending on the type of engine, sufficient lubrication is provided at high speeds, but
Some parts may lack lubrication when rotating at low speeds. During high-speed rotation, for example, oil leaking from the bearing of the Lonca arm is agitated by the behavior of the valve spring and scatters, forming an oil mist that lubricates the valve shaft appropriately, but during low-speed rotation, this oil is not supplied. This is because there is less oil mist generated.

Therefore, as shown in FIG.
Figure 4 of Publication No. 3).

It is designed to supply main oil to the supply and exhaust valve shafts via the blow-by gas of engine E, and
A valve shaft ifl oil passage 13 is provided in the head cover 33, and its oil outlet 13C is opened toward the valve shaft head 6a, and a lubricant pump P driven by the engine E supplies lubricating oil O to the valve shaft 6 and the valve shaft. It is configured so that it is constantly supplied to the sliding gap with the guide hole 25a. In addition, in the figure, reference numeral 5 is a supply/exhaust valve, 10 is a port 7 arm, 25 is a valve shaft guide, and 30 is a pulp spring.

[Problem to be solved by the invention]

In the above conventional example, when the engine rotates at low speed, pressure-fed oil is supplied from the oil outlet 13C to the valve shaft guide hole 2.
5a is sufficiently lubricated, but during high-speed operation, the valve shaft guide hole 25a is lubricated excessively by the amount of the pumped oil, causing oil to drip from the valve shaft guide hole 25a to the supply/exhaust boat.

The technical object of the present invention is to ensure the amount of lubricating oil during low-speed rotation to prevent seizure of the valve stem, while also eliminating oil dripping into the supply/exhaust boat during high-speed rotation.

[Means to solve the problem]

In order to solve the above problems, the present invention is configured as follows.

That is, the oil outlet 13 of the valve shaft lubricating oil passage 13 of the engine E
c is opened toward at least one valve shaft 6 of the supply/exhaust valve 5, and a lubricant pump P driven by the engine E supplies lubricating oil O to the sliding gap 26 between the valve shaft 6 and the valve shaft guide hole 25a. In the valve shaft lubrication system for an engine configured to do this, a hydraulically operated valve 15 is interposed in the valve shaft lubricating oil passage 13, and the hydraulically operated valve 15 moves to the valve opening side when the oil pressure in the valve stem lubricating oil passage 13 is low. However, when the oil pressure is high, the valve closes.

[For production]

The present invention configured as described above operates as follows.

First, while the engine is rotating at low speed, the rotational speed of the lubricating pump P is also low and the oil pressure in the valve shaft lubricating oil passage 13 is low, so the hydraulically operated valve 15 is operated toward the valve opening side. Therefore, the lubricating oil is pressure-fed through the hydraulically operated valve 15 and is sufficiently supplied to the sliding gap between the valve shaft 6 and the valve shaft guide hole 25a. On the other hand, when the engine E reaches a predetermined high speed, the lubricating pump P
The rotational speed of the valve shaft lubrication oil passage 13 also increases, and the oil pressure of the valve shaft lubricating oil passage 13 also increases. Then, the hydraulically operated valve 15 is operated to the valve closing side, and oil supply by pressure feeding to the valve shaft 6 is stopped.

Note that during high-speed rotation, for example, oil leaking from the bearing portion of the rocker arm 10 is agitated by the behavior of the valve spring 30 and scatters, becoming oil mist, and the valve shaft 6 is appropriately lubricated by this main oil mist.

This simultaneously eliminates the problems of insufficient oil during low-speed rotation and excessive lubrication during high-speed rotation.

〔Example〕

Hereinafter, the present invention will be explained in detail based on the drawings.

FIG. 1 is a vertical sectional view of the main part showing the first embodiment, and FIG. 2 is a
FIG. 2 is a longitudinal sectional front view of an overhead valve engine equipped with the valve shaft lubricating device.

As shown in FIG. 2, this engine E has a piston 2 fitted into a cylinder l so that it can slide vertically, a crankshaft 4 and the piston 2 are interlocked and connected via a connecting rod 3, and the piston 2 is positioned above the piston 2. An intake and exhaust valve 5 is installed in the main combustion chamber (not shown).
facing the auxiliary combustion chamber (not shown), arrange the valve drive camshaft 7 and bushing rod 8 to the right of the piston 2, swing the rocker arm IO with the bushing rod 8, and push down the valve stem 6 with the rocker arm IO. , and are configured to open and close the supply and exhaust valves 5. Note that the reference numeral 35 in the figure is a blazer device, and the blazer device 35 separates the oil mist contained in the blow-by gas rising into the head cover 33 through the valve train cam chamber 7a and the push rod insertion hole 8a. It is configured as follows.

A first embodiment of the valve shaft lubricating device according to the present invention will be described below.

As shown in FIG. 1, this valve shaft lubricating device has a valve shaft lubricating oil passage 13 formed in a rocker arm 10, an oil passage 13a thereof being connected to an oil passage 12 in a rocker arm shaft 11, and an oil passage 13 formed in a rocker arm 10. The outlet 13c is opened facing the concave portion 21 of the retainer 20 of the valve shaft head 6a, and the valve shaft lubricating oil path 1 is opened.
3 with a hydraulically operated valve 15 interposed therebetween.

As shown in FIG. 2, the oil passage 12 in the rocker arm shaft 11 is connected to a lubricating pump P driven by the engine E via a pressure passage.

The hydraulically operated valve 15 has a valve insertion hole 16 formed from the output side end of the rocker arm 10, and the inlet port 13b of the valve shaft lubricating oil passage 13 is exposed to the inner end surface of the valve insertion hole 16, and the valve is inserted therethrough. An oil outlet 13C is opened on the inner surface of the lower wall of the hole 6, and a valve 17 formed to allow communication between the inlet boat 13b and the oil outlet 13C is inserted into the valve insertion hole 6 so as to be freely retractable.
7 is pressed and biased to the valve opening side via the valve opening spring 18 with the pressure adjustment screw 19 so that the pressure can be adjusted, and when the oil pressure of the valve shaft ilIl oil slide 13 is low, the valve element 17 is operated to the valve opening side, When the oil pressure becomes high, the valve 17 is moved against the pressure regulating spring 18 by the oil pressure,
Insert it back to the stopper 19a attached to the pressure adjustment screw 19,
It is configured to operate toward the valve closing side.

In other words, when the engine rotates at low speed, lubricating oil O is sufficiently supplied to the valve shaft head 6a to eliminate oil shortage, and after reaching high speed rotation, the supply of lubricating oil O from the valve shaft lubricating oil passage 13 is stopped. This prevents oil from dripping due to excessive lubrication by using only normal mist lubrication.

In FIG. 1, reference numeral 22 denotes two collets formed separately, and the lubricating oil O dripping from the oil outlet 13C is absorbed into the concave portion 21 formed by the conical hollow portion of the retainer 20 and the upper surface of the collet 22. This concave portion 2
1 to the valve shaft 6 to lubricate the sliding gap between the valve shaft 6 and the valve shaft guide 25.

In the above description, the valve shaft lubricating oil passage (3) is formed in the rocker arm 10, but for example, the first
As shown by the imaginary line in the figure, a valve shaft lubricating oil passage 13A is formed in the cylinder head 31, and its oil outlet 13C is opened to face the valve shaft spring seat type 32 or the valve shaft guide hole 25a, A hydraulically operated valve 15A is connected to the valve shaft lubricating oil passage 13A.
may be interposed.

FIG. 3 is a vertical sectional view of a main part showing a second embodiment of the present invention.

This embodiment differs from the first embodiment in that the valve shaft lubricating oil passage 13 is formed in the rocker arm 10 and in the middle of the valve shaft 6, and other points are the same as in FIG. be. Note that reference numeral 13d in FIG. 3 is an oil reservoir, and when the valve shaft 6 is pushed down by the rocker arm IO at the time of starting the engine, the lubricating oil in the oil reservoir 13d is pushed down by the inclined surface 24 due to its own static inertia. Oil outlet 13c
It seems to be pushed out from Therefore, even if there is a delay in the supply of lubricating oil by the lubricant pump P when starting the engine, the lubrication failure within the valve shaft guide hole 5a can be resolved.

FIG. 4 is a vertical sectional view of a main part showing a third embodiment of the present invention.

In this embodiment, the valve shaft lubricating oil passage 13 is provided in the head cover 33 of the engine as in the conventional example (FIG. 5), and its oil outlet 13G is opened toward the valve shaft head 6a.
A hydraulically operated valve 15 similar to that shown in FIG. 1' is interposed on the upstream side of the valve 3c.

In the above embodiments, an overhead valve type engine is illustrated, but the invention is not limited to this, and various modifications can be made to the structure of the hydraulically operated valve.

〔Effect of the invention〕

As is clear from the above description, in the present invention, a hydraulically operated valve is interposed in the valve shaft lubricating oil passage, while using both main stroke lubrication and pressure-feeding lubrication, forced lubrication is performed when the engine rotates at low speeds, and lubrication is performed when the engine rotates at high speeds. By stopping forced lubrication and using main stroke lubrication, we can secure the amount of lubricating oil during low speed rotation and prevent seizure of the valve stem, while also eliminating oil dripping into the intake and exhaust boats during high speed rotation. can.

[Brief explanation of drawings]

1 to 4 show embodiments of the present invention, FIG. 1 is a vertical sectional view of main parts showing a first embodiment of a valve shaft lubrication device, and FIG. 2 is a diagram showing the valve shaft lubrication device. 3 is a longitudinal sectional front view of the overhead valve type engine, and FIG. 3 is a view corresponding to FIG. 1 showing the second embodiment, and FIG.
The figure is a diagram equivalent to FIG. 1 showing the third embodiment, and FIG. 5 is a diagram equivalent to FIG. 1 showing a conventional example. E... Engine, P... Lubricating pump, 0... Lubricating oil, 5... Intake and exhaust valve, 6... Valve shaft, 13... Valve shaft ill oil passage, 13c... Oil outlet, 15... Hydraulic operated valve, 25a... Valve shaft guide hole, 26... Sliding gap. Patent applicant Kubota Iron Works Co., Ltd. Figure 3 Figure 4 Figure 5 Figure 3

Claims (1)

[Claims] 1. Oil outlet 13c of valve shaft lubricating oil passage 13 of engine E
is opened toward at least one valve shaft 6 of the supply/exhaust valve 5, and a lubricant pump P driven by the engine E supplies lubricating oil O to the sliding gap 26 between the valve shaft 6 and the valve shaft guide hole 25a. In the engine valve shaft lubrication system configured as above, a hydraulically operated valve 15 is interposed in the valve shaft lubricating oil passage 13, and the hydraulically operated valve 15 is operated to the valve opening side when the oil pressure in the valve stem lubricating oil passage 13 is low. An engine valve shaft lubricating device characterized in that it is configured to operate toward the valve closing side when the oil pressure is high.