JPH0217130Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a valve mechanism for a Rocker arm type hydraulic lifter.

Generally, in OHC rocker arm type hydraulic lifters, air is mixed in the engine oil supplied to the hollow rocker shaft. When oil mixed with air is supplied to the hydraulic lifter in this way, when the plunger of the hydraulic lifter rises, this oil no longer acts as a rigid body, and the plunger pushed by the cam comes into contact with the stopper, producing a hitting sound. There was a drawback.

This invention removes air bubbles from the engine oil supplied to the hollow rocker shaft and supplies it to the hydraulic lifter, thereby preventing the occurrence of hammering noise, especially when air is likely to be mixed in, such as when starting the engine or during sudden acceleration. The object of the present invention is to obtain a valve operating mechanism for a hydraulic lifter that can prevent the above problems.

In order to achieve this object, the present invention provides a hydraulic lifter of the rocker arm type in which engine oil supplied to a hollow rocker shaft is supplied to the hydraulic lifter. The air in the engine oil supplied from the oil supply port of the hollow rocker shaft collects in the upper part of the hollow part of the rocker shaft, and then passes through one end of the rocker shaft or The air bubbles accumulate in the upper part of the air separation chamber provided at both ends, and when the air separation chamber is full of oil, these air bubbles fall into the engine oil pan along with the oil through the small air vent hole at the top, and the oil without air bubbles is removed. , is supplied from the supply hole in the hollow part of the rocker shaft to the reservoir of the hydraulic lifter located lower than the air vent hole of the air separation chamber.

Therefore, according to the present invention, since air bubbles are not mixed in the engine oil supplied to the hydraulic lifter, the oil in the hydraulic lifter no longer acts as a rigid body due to the air bubbles as in the conventional case, and the plunger of the hydraulic lifter There are no drawbacks such as hitting the stopper and making a hitting sound.

An embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is a partial cross-sectional plan view of a hydraulic lifter valve mechanism showing an embodiment of the invention, and Fig. 2 is a plan view from A to A in Fig. 1.
A cross-sectional view, and FIG. 3 are cross-sectional views taken along line B-B in FIG. 1. In the figure, 1 is a hollow rocker shaft.
Engine oil 3 is supplied to the hollow portion of the shaft from an oil supply port 2.

An air separation chamber 6 is connected to one or both ends of the rocker shaft 1 and communicates with the hollow portion 4 of the shaft via an inlet 5. The engine oil 3 supplied to the hollow part 4 of the Rocker shaft is passed from the supply hole 7 provided in the lower part of the hollow part 4 through the passage 9 in the Rocker arm 8 to the Rocker arm 8.
Reservoir 1 of hydraulic lifter 10 built in one end
1.

Next, the valve operating mechanism of the hydraulic lifter will be explained with reference to FIG. The valve stem 14 is biased in the closing direction by a spring 16 stretched between the valve stem 14 and the engine body 12, and the upper end of the valve stem 14 is connected to the hydraulic lifter 10.
is always in contact with the bottom surface of the When the camshaft 17 rotates, the cam 18 causes the rocker arm 8 to swing around the rocker shaft 1 as a fulcrum.
The valve stem 14 is pushed down via the hydraulic lifter 10 to open the valve 13.

On the other hand, the air bubbles in the engine oil 3 in the hollow part 4 gather in the upper part of the hollow part 4, and then pass through the inlet 5 and accumulate in the upper part of the air separation chamber 6. Therefore, since the supply hole 7 of the hollow part 4 is provided at the lowest part of the hollow part 4, no air bubbles flow out from the supply hole 7. After that, when the air separation chamber 6 is filled with oil, the air bubbles accumulated in the upper part fall into the oil pan of the engine through the small air vent hole 19 at the top, along with some of the oil.

[Brief explanation of the drawing]

Fig. 1 is a partial cross-sectional plan view of a hydraulic lifter valve mechanism showing an embodiment of the present invention, and Fig. 2 is A to A in Fig. 1.
The sectional view, FIG. 3, is a sectional view taken along line B-B in FIG. 1. Explanation of the main parts of the diagram, 1...Rotscar shaft, 2...Oil supply port, 3...Engine oil, 4...Hollow part, 5...Inlet, 6...Air separation chamber, 7...Supply hole, 8 ...Rotskar arm, 10
... Hydraulic lifter, 11 ... Reservoir, 13 ... Valve, 18 ... Cam.

Claims (1)

[Scope of utility model registration request] In a hydraulic lifter of the rocker arm type in which the engine oil supplied to the hollow rocker shaft is supplied to the hydraulic lifter, an air separation chamber communicating with the hollow part of the shaft is provided at one end or both ends of the rocker shaft. Features a hydraulic lifter valve mechanism.