JPS61250321A - Valve gear-cum-hydraulic tappet device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To dispense with an exclusive air bleed passage, by having a lubricating oil passage to be formed in a cylinder head interconnected to a bottom part of the support hole formed in the cylinder head, while making the said oil passage serve as an air bleed passage at the time of a tappet setup. CONSTITUTION:Oil feed passages 29, 29 and lubricating oil passages 30, 30 are all installed in the central part of a cylinder head 2 nearly in parallel with a direction toward a crank shaft as adjoining to both support holes 13 where each hydraulic tappet 10 in a valve gear 11. Each of these oil feed passages 29 is interconnected to the inside of each support hole 13 and connected to an oil feed hole of the hydraulic tappet 10. And, each lubricating oil passage 30 is interconnected to each bearing surface of bearings 27 and 28 for valve gear cam shafts 17 and 18 via a distributing passage (unillustrated herein) interconnected to these lubricating oil passages. In addition, each lubricating oil passage 30 is interconnected to each bottom part of these support holes 13, and when each hydraulic tappet 10 is installed in these support holes 13, these lubricating oil passages are made so as to be utilizable an air bleed passage to be sealed between these support holes.

Description

[Detailed description of the invention] A0 Purpose of invention (1) Industrial application field The present invention relates to a valve train with a hydraulic tappet.

(2) Prior Art A conventional valve operating system for an internal combustion engine is known in which a hydraulic tappet is attached so that adjustment of the valve gap is not required (see Japanese Patent Laid-Open No. 58-210309).

(3) Problems to be Solved by the Invention By the way, the hydraulic tappet is installed and supported in a support hole provided in the engine body, but in order to facilitate the installation, air is sealed between the support hole and the hydraulic tappet. It is necessary to bleed the air out of the cylinder head, and for this reason, conventionally, there is the trouble of drilling a dedicated air bleed passage in the cylinder head that communicates with the bottom of the support hole.

Therefore, the present invention provides a hydraulic tappet-equipped engine for an internal combustion engine that allows the air to be bleed without drilling such a dedicated air bleed hole, thereby eliminating the need for the special provision of the dedicated air bleed passage. The object of the present invention is to provide a valve device.

B6 Structure of the Invention (1) Means for Solving the Problems In order to achieve the above-mentioned object, the present invention provides a structure in which a cam follower is swingably supported at the operating end of a hydraulic tappet installed in a support hole formed in a cylinder head of an engine body. An on-off valve is connected to the other end of the cam follower, and the on-off valve is opened and closed via the cam follower by a valve drive cam on a valve drive cam shaft rotatably supported by the cylinder head. In the valve train of an engine, the cylinder head includes an oil supply passage adjacent to the support hole for supplying pressure oil to the hydraulic tappet, and lubricating oil for lubricating a bearing of the valve train camshaft, etc. The lubricating oil passage is made to communicate with the bottom of the support hole, and the core oil passage also serves as an air release passage when the hydraulic tappet is installed.

(2) Function According to the above configuration, when the hydraulic tappet is installed in the support hole formed in the cylinder head, the air sealed between them is discharged to the outside through the lubricating oil passage of the valve mechanism.

(3) Examples Next, one embodiment of the present invention will be described.

An engine body E of a DOHC type four-stroke internal combustion engine includes a cylinder block 1 and a cylinder head 2 which is superimposed and bonded thereon via a gasket 3.

The cylinder head 2 of the engine body E is equipped with a spark plug 4,
Combustion chamber 5 and intake and exhaust ports 6 opening into the combustion chamber 5
．． 7 are formed, and these boats 6.7 are respectively opened and closed by intake and exhaust valves 8.9 supported on the cylinder head 2 so as to be movable up and down.

The intake and exhaust valves 8.9 each have a hydraulic tappet 10.1.
The opening/closing operation is performed at a predetermined timing by a valve operating mechanism 11 equipped with a valve mechanism 11 having a valve mechanism 11.

The valve train 11 is provided in a valve train chamber 12 formed on the upper surface of the cylinder head 2 .

The valve mechanism 11 with the hydraulic tappet 10 has a conventionally known structure, and a pair of V-shaped support holes 13.13 are formed in the center of the cylinder head 2. Hydraulic tapefs) 10 and 10 are respectively installed. One end of a suction/exhaust cam follower 15.16 is connected to the operating end of each hydraulic tappet 10.10, that is, the spherical upper end of the plunger 14.14, and the other end of the cam follower 15.16 is connected to a valve spring 21, 22 engages with the upper ends of the on-off valves, that is, the intake and exhaust valves 8.9, which are biased in the valve-closing direction. The valve drive cams 19 of the pair of valve drive cam shafts 17.18 are attached to the slipper surfaces formed on the upper surfaces of the intermediate portions of the intake and exhaust cam followers 15.16, respectively.
．． 20 are pressed against each other, and the intake and exhaust valves 8.
9 is opened and closed at a predetermined timing. A pair of valve drive camshafts 17.18 for intake and exhaust have bearings formed by bearing halves 23.24 formed on the cylinder head 2 and bearing caps 25.26 fixed to their upper surfaces. 27
．． 28, respectively rotatably supported.

The support hole 13.13 is located in the center of the cylinder head 2.
An oil supply passage 29.29 and a lubricating oil passage 30.30 are bored approximately parallel to the crankshaft direction adjacent to the support hole 13.13, and the oil supply passage 29.29 is adjacent to the support hole 13. .13 and is connected to the oil supply hole of the hydraulic tab (10.10) installed in the support hole 13.13. Hydraulic tappet) 10.10 has a conventionally known structure, and the oil supply path 2
It is operated by receiving pressure oil from 9.29, and its upper end is pressed against the swinging support part of the cam follower 15.16. The lubricating oil passage 30.30 also communicates with a distribution passage 32:32 bored in the cylinder head 2, as shown in FIG.
．． 28 bearing surfaces are respectively opened. Although not shown, the lubricating oil in the lubricating oil passage 30 is supplied to other lubricated parts of the valve mechanism 11,
For example, cam follower 15.16 and valve drive cam 19°20
It can also be supplied to the connecting surface. Further, as shown in FIG. 1, the - side of the lubricating oil passages 30.30 are communicated with the bottoms of the support holes 13.13, respectively, and hydraulic tappets (10.10) are connected to the support holes 13.13, respectively. When installed, it is used as an air release passage for the air sealed between them.

Next, the operation of the embodiment of the present invention will be explained.

If the pair of valve drive cam shafts 17 and 18 are now rotated due to engine operation, the valve drive cams 19 and 20 will rotate and the valve spring 21 will rotate.
．． 22, the cam follower 15.16 swings up and down using the joint with the hydraulic tappet 10.10 as a fulcrum, and slides the suction and exhaust valves 8 and 9 up and down to open the suction and exhaust ports 6.
．． 7 is opened and closed at a predetermined timing.

Further, pressurized oil from a hydraulic pump driven by engine operation is divided into oil supply passages 29.29 and lubricating oil passages 30.30, and pressure oil flowing through oil supply passages 29.29 is supplied to support holes 13.
13 to the hydraulic tappets 10.10, which actuate the hydraulic tappets 10.10 to press their working ends against the cam followers 15.16. Also, the lubrication passage 30.3-
The lubricating oil flowing through the valve cam 17.18 is supplied to the bearing 27.28 of the valve drive cam 17.18 through the distribution passage 32.32.

When the hydraulic tappet 10.10 is installed in the support hole 13.13, air is sealed in the support hole 13.13, but the sealed air passes through the lubricating oil path 30.30 to the outside. ejected into the support hole 13. of said hydraulic tappet 10.10.
13 becomes easy to attach.

C0 Effects of the Invention As is clear from the above embodiments, according to the present invention, an oil supply path for supplying pressure oil to the hydraulic tappet is provided in the cylinder head adjacent to the support hole formed in the cylinder head;
A lubricating oil passage for lubricating the bearing portion of the valve drive camshaft, etc. is drilled, and the lubricating oil passage is communicated with the bottom of the support hole, and the oil passage is used as an air bleed passage when the hydraulic tappet is installed. Since it is also used, the lubricating oil path can be used as a passage to bleed the sealed air when installing the hydraulic tappet into the support hole, and there is no need to provide a special air bleed passage in the cylinder head, which reduces processing costs for the cylinder head. can contribute.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a vertical cross-sectional view of a valve train in an engine body equipped with the device of the present invention, and FIG. 2 is a bearing of a valve camshaft in the engine body. FIG. E...engine body,

Claims (1)

[Claims] A cam follower is swingably supported at the operating end of a hydraulic tappet installed in a support hole formed in a cylinder head of the engine body, an on-off valve is connected to the other end of the cam follower, and the cam follower is rotatably supported by the cylinder head. In the valve train for an internal combustion engine, the valve drive cam on the valve drive camshaft opens and closes the on-off valve via the cam follower, and the cylinder head includes the hydraulic tappet adjacent to the support hole. An oil supply passage for supplying pressure oil to the valve drive camshaft and a lubricating oil passage for lubricating the bearings of the valve drive camshaft, etc. are bored, and the lubricating oil passage is communicated with the bottom of the support hole to supply the oil. A valve train with a hydraulic tappet for an internal combustion engine, characterized in that a passageway is also used as an air release passage when a hydraulic tappet is installed.