JPH0318648Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a hydraulic valve lifter for an overhead cam type engine.

[Conventional technology]

In overhead cam type engines, the fourth
As shown in the figure, a valve 4 is interposed between the port 2 of the cylinder head 1 and the combustion chamber 3.
is located at the lower end of a valve rod 5 which is slidably attached to the cylinder head 1 via a sleeve 6, and the upper end of the valve rod 5 communicates with a valve lifter 7;
The upper surface of the tappet body 8 of the valve lifter 7 is in contact with the cam 9. And the valve 4 is a valve rod 5
and springs 10, 11 via the tapepet body 8.
is biased toward the upper cam 9 side. As the cam 9 rotates, the valve 4 is pushed down through the tappet body 8 and the valve rod 5 that are in contact with it, and the valve 4 is pushed up through the tappet body 8 and the valve rod 5 by the springs 10 and 11, thus causing the valve to open. 4 opens and closes between the port 2 and the combustion chamber 3.

As shown in FIG. 5, the conventional valve lifter 7 has a tappet body 8 divided into an upper chamber 83 and a lower chamber 84 by a partition wall 81 having a fitting hole 82 with a sliding tube 82A attached to the center. A lower plunger 85 is fitted into the sliding tube 82 of the fitting hole 82 and has a cylinder chamber 85A that opens upward, and a lower plunger 85 is fitted into the cylinder chamber 85A of the lower plunger 85 and has a communication port 86A at the bottom. Has a seat 86 at the bottom
An upper plunger 86 having a shape B, and a cup 8 whose upper edge abuts the lower surface of the upper plunger 86 as a check valve mechanism 87 incorporated in the communication port 86A.
7A, and a ball 87B that opens and closes the communication port 86A of the upper plunger 86 within the cup 87A.
A spring 87C is provided between the bottom surface of the cup 87A and the ball 87B and pushes up the ball 87B toward the communication port 86A.
7D, the upper plunger 86 is urged upwardly by the lower plunger 85, and the upper edge is formed by the sheet 89 on the upper inner wall of the tappet body 8.
It is coming into contact with the Note that 12 is a spring seat fitted to the upper end of the valve rod 5. The upper chamber 83 of the tapepet main body 8 is connected to the inner first reservoir 83 by the upper plunger 86.
A and an outer second reservoir 83B.

The oil supply means in the conventional valve lifter 7 is provided with an annular groove 8A on the outer periphery of the tappet body 8, an oil passage 13 provided on the cylinder head 1 side over the vertical movement range of the annular groove 8A, and an oil passage 13 provided at the upper edge of the annular groove 8A. An oil guide hole 88 was provided between the tappet body 8 and the second reservoir 83B of the tappet body 8.

In the above configuration, during engine operation, oil pressure is applied to the annular groove 8A of the tappet body 8 through the oil passage 13 of the cylinder head 1, and thus lubricating oil flows through the oil guide hole 88 into the second reservoir 83B of the tappet body. guided and further upper plunger 86
is guided into the first reservoir 83A from the upper edge of the
The cylinder chamber 8 of the lower plunger 85 is prevented from backflowing from the first reservoir 83A through the communication port 86A by the check valve mechanism 87 and is regulated by the elasticity of the springs 87C and 87D.
It reaches 5A.

[Problem that the invention attempts to solve]

In the above conventional structure, the oil guide hole 88 provided in the tappet body 8 is connected to the annular groove 8A of the tappet body 8.
An opening was opened at the bottom of the second reservoir 83B to communicate with the second reservoir 83B. Therefore, the lubricating oil accumulated in the second reservoir 83B when the engine is stopped flows into the oil guide hole 88.
It may go out and reach the combustion chamber 3, causing engine malfunction.

[Means to solve the problem]

The purpose of the present invention is to solve the above-mentioned problems, and in order to achieve the above-mentioned purpose, the present invention is divided into an upper chamber and a lower chamber by a partition wall having a fitting hole in the center. a lower plunger that is fitted into a fitting hole in the partition wall and has a cylinder chamber that opens upward; and an upper plunger that is fitted into the cylinder chamber of the lower plunger and has a communication port at the bottom; It consists of a check valve mechanism built into the communication port of the upper plunger and a spring that biases the upper plunger in the direction of pushing it out from the lower plunger. In a hydraulic valve lifter that is divided into an outer second reservoir, an oil supply passage is provided internally along the outer circumference of the upper edge of the tappet body, and the oil supply passage has an oil supply hole that communicates with the second reservoir, and an oil supply hole that communicates with the second reservoir. The main feature is a hydraulic valve lifter that communicates with an oil guide hole.

[Effect]

Since the present invention has the above-mentioned configuration, lubricating oil is introduced into the oil supply passage from the oil guide hole during engine operation.
The oil is further supplied from the oil supply passage to the second reservoir via the oil supply hole.

[Effect of idea]

Since the present invention has the above-mentioned effects, the lubricant oil droplets in the second reservoir are prevented from flowing back to the outside from the oil guide hole during engine operation, and even after the engine is stopped, the lubricant oil accumulated in the second reservoir is The valve lifter does not reach the oil supply passage through the oil supply hole, and therefore, even if the valve lifter is arranged at an angle, it is reliably prevented from coming out of the oil supply hole of the tappet body.

〔Example〕

To explain the present invention with reference to an embodiment shown in FIGS. 1 and 2, reference numeral 8 denotes a tappet body of the valve lifter 7, which is divided by a partition wall 81 into an upper chamber 83 and a lower chamber 84. A fitting hole 82 is provided in the center of the partition wall 81, and a sliding tube 82A is vertically provided from the fitting hole 82 to the lower chamber 84 side.
A stopper 82B is attached to the lower edge of 2A. The sliding tube 82A has a cylinder chamber 85 that opens upward.
A lower plunger 85 having an internal diameter A is slidably fitted therein, and an upper plunger 86 is further slidably fitted into the cylinder chamber 85A of the lower plunger 85. The upper plunger 86 has a communication port 86A at the bottom and a seat 86B at the bottom.
A cup 87A is formed on the lower side of the communication port 86A, that is, on the lower plunger 85 side, and the upper edge of the cup 87A contacts the lower surface of the upper plunger 86.
7A, the communication port 86A of the upper plunger 86
A check valve mechanism 87 is incorporated, which includes a ball 87B that opens and closes the cup 87B, and a spring 87C that is passed between the bottom surface of the cup 87 and the ball 87B and pushes the ball 87B toward the communication port 86A. The upper plunger 86 and the cup 87A are urged upward by the spring 87D, that is, in the direction in which the upper plunger 86 is pushed out from the lower plunger 85, so that the upper edge comes into contact with the sheet 89 on the upper inner wall of the tapepet body 8. ing. A valve rod 5 is connected to the lower plunger 86, and a seat 12 of springs 10, 11 is fitted into the upper end of the valve rod 5. In the above configuration, the upper chamber 82 of the tapepet main body 8 is divided by the upper plunger 86 into an inner first reservoir 83A and an outer second reservoir 83B.

As a lubricating means in the valve lifter 7, an annular groove 8A is provided on the outer periphery of the tappet body 8,
An annular oil supply passage 881 at the upper edge of the tappet body 8
An annular groove 8A is provided at one end of the oil supply passage 881.
An oil guide hole 88 is provided at the upper edge of the
An oil supply hole 882 that opens into the reservoir 83B is provided.

In the above configuration, during engine operation, hydraulic pressure is applied to the annular groove 8A of the tappet body 8 through the oil passage 13 of the cylinder head 1, as in the conventional example, and lubricating oil is supplied to the oil supply passage of the tappet body 8 through the oil guide hole 88. 881, goes around the inside of the oil supply passage 881, is guided into the second reservoir 83B from the oil supply hole 882, is further led into the first reservoir 83A via the upper edge of the upper plunger 86, and is guided into the first reservoir 83A through the upper edge of the upper plunger 86. A check valve mechanism 87 prevents backflow from 83A through a communication port 86A, and a spring 87
The pressure regulated by the elasticity of C and 87D reaches the cylinder chamber 85A of the lower plunger 85. When the engine is stopped, the oil supply passage 881 is located at a high position in the tappet body 8, so the second
The lubricating oil accumulated in the reservoir 83B is in the oil supply hole 8
82 into the oil supply passage 881 is not possible.

FIG. 3 shows another embodiment of the oil supply passage 881. In this embodiment, the oil supply passage 881 is semi-circular, with an oil guide hole 88 communicating with it at one end and an oil supply hole 882 at the other end.
is in contact.

[Brief explanation of drawings]

1 and 2 show one embodiment of the present invention, FIG. 1 is a sectional view, FIG. 2 is a sectional view taken along line A-A' in FIG. 1, and FIG. A cross-sectional view corresponding to the A-A′ cross-sectional view in FIG. 1 of the embodiment,
Figure 4 is an explanatory diagram of the arrangement of the valve lifter mechanism, Figure 5
The figure is a sectional view of a conventional example. In the figure, 7... Valve lifter, 8... Tappet body, 81... Partition wall, 82... Fitting hole, 83...
Upper chamber, 84... Lower chamber, 83A... First reservoir, 83B... Second reservoir, 85A... Cylinder chamber, 85... Lower plunger, 86...
Upper plunger, 86A... Connection port, 87...
Check valve mechanism, 87C, 87D...Spring, 8
8...Oil guide hole, 881...Oil supply passage, 882...
Refueling hole.

Claims (1)

[Scope of utility model registration request] A tapepet body is divided into an upper chamber and a lower chamber by a partition wall having a fitting hole in the center, and a lower plunger is fitted into the fitting hole of the partition wall and has a cylinder chamber that opens upward. , an upper plunger fitted into the cylinder chamber of the lower plunger and having a communication port at the bottom; a check valve mechanism incorporated in the communication port of the upper plunger; and a biasing direction in which the upper plunger is pushed out from the lower plunger. In a hydraulic valve lifter, the upper chamber of the tappet body is divided by an upper plunger into a first reservoir on the inside and a second reservoir on the outside. A hydraulic valve lifter, characterized in that the oil supply passage is provided internally, and the oil supply passage communicates with an oil supply hole that communicates with the second reservoir and an oil guide hole that communicates with the outside.