JPS61261614A - Oil feeder of tappet mechanism equipped with hydraulic tappet for internal-combustion engine - Google Patents

Abstract

PURPOSE:To enable feeding of always proper amount of pressurized oil to each oil system by forming, in two tiers to a cylinder head, a lubricant oil system serving lubricated parts of a valve actuating system, and an oil feeding system serving hydraulic tappets, and by inserting a flow control orifice between each oil system. CONSTITUTION:A oil feeding system L1 to feed pressurized oil to hydraulic tappets 10... and a lubricant oil system L2 to feed pressurized oil to bearing parts 27, 28 of valve actuating cam shafts 17, 18 are formed to a cylinder head 2 in two almost horizontal parallel tiers with some space inbetween. Two oil systems L1, L2 formed so that their oil passages are positioned in the plane shape of H, and are connected to a main oil passage 35 from their central parts through an oil feeding passage 30. An orifice 37 for flow control is inserted along each oil feeding passage 37, and a relief valve 42 is also inserted to the rim part downstream the orifice 37. The main oil passage 35 stretches up and down the cylinder head 2 to serve as a connecting hole of a head bolt 4, and its lower end is connected by a channel to a hydraulic pump.

Description

DETAILED DESCRIPTION OF THE INVENTION A0 OBJECTS OF THE INVENTION (11) INDUSTRIAL APPLICATION FIELD The present invention relates to a lubricating system for a valve train of an internal combustion engine, which is equipped with a hydraulic tappet.

(2) Prior art It is known that a hydraulic tappet is attached to the valve mechanism of a conventional internal combustion engine, thereby eliminating the need to adjust the valve clearance between the valve cam and the intake and exhaust valves (in practice). Showa 58-126
(See Publication No. 07).

(3) Problems to be Solved by the Invention Incidentally, such a hydraulic tappet action valve device requires an oil supply system for supplying hydraulic oil to the hydraulic tappet, and a lubricating oil system for lubricating the bearings of the valve drive camshaft, etc. However, in conventional systems, if the oil pressure in the oil supply system to the hydraulic tappet becomes excessive, the relief valve in the system opens, making it impossible to supply oil to the bearing of the valve drive camshaft. Furthermore, there is a problem in that it is not possible to adjust the oil tg of the oil supply system for the hydraulic tappet and the lubricating oil system for the bearing of the valve drive camshaft.

The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a refueling device for a valve mechanism with a hydraulic tappet for an internal combustion engine, which has a simple structure and can solve all of the above-mentioned problems.

B0 Structure of the Invention (1) Means for Solving Problems According to the present invention, in order to achieve the above object, a hydraulic tappet is attached to the cylinder head of the engine body, and this hydraulic tappet is connected to the on-off valve via a cam follower. The on-off valve is opened and closed by cooperation between the cam follower, which is connected to each other and swings in relation to the rotation of the valve-driving cam on the valve-driving camshaft, and a valve spring that biases the on-off valve in the valve-closing direction. In the valve mechanism with a hydraulic tappet, the cylinder head includes an oil supply system for supplying hydraulic oil to the hydraulic tappet, and a lubricating oil system for supplying lubricating oil to a bearing of the valve camshaft, etc. and a first and second orifice for flow rate control are inserted in the middle of the oil supply system and the lubricating oil system, respectively, and the first and second orifices are installed in the middle of the oil supply system and the lubricating oil system, respectively. Upstream of the second orifice, the oil supply system and the lubricating oil system are connected in parallel to a main oil passage connected to a hydraulic pressure source.

(2) Effect According to the above configuration, an appropriate amount of pressure oil is always supplied to the oil supply path to the hydraulic tappet and the lubricating oil path to the bearings of the valve drive camshaft.

(3) Embodiments Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

The engine body E of the DOHC type four-stroke internal combustion engine includes a cylinder block 1 and a cylinder head 2 superposed thereon via a gasket 3, which are joined together by head bolts 4 (Fig. 5). It wears out.

The cylinder head 2 of the engine body E is formed with a combustion chamber 5 and intake and exhaust boats 6.7 opening into the combustion chamber 5.
These boats 6 and 7 are opened and closed by intake and exhaust valves 8 and 9, respectively, which are supported on the cylinder head 2 so as to be able to rise and fall.

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 operating mechanism 11 is provided within a valve operating 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 tabs) 10 and 10 are respectively installed. One end of a suction/exhaust cam follower 15.16 is connected to the working 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, 21 are engaged with the upper ends of the intake and exhaust valves 8 and 9, respectively, which are biased in the valve closing direction. Valve drive cams 19.20 of a pair of valve drive camshafts 17.18 are pressed into slipper surfaces formed on the upper surfaces of intermediate portions of intake and exhaust cam followers 15.16, respectively.
The rotation of these valve drive cams 19, 20 and the valve spring 21,
22, the intake and exhaust valves 8 and 9 are opened and closed at predetermined timing. A pair of valve drive camshafts 1 for intake and exhaust
7.18 is the bearing half 23.24 on the cylinder head 2
and bearing caps 25 and 26 fixed thereon, respectively.

The cylinder head 2 includes an oil supply system for supplying pressure oil to the hydraulic tappets 10, 10, and a valve drive camshaft 17.
A lubricating oil system L2 for supplying pressure oil to the 18 bearings is arranged substantially horizontally in parallel with an interval above and below. As shown in Fig. 3.5, the oil supply system includes an oil supply passage 30 that extends across the cylinder head 2 in the width direction, and two oil supply passages that branch off from this oil supply passage 30 to the left and right and extend parallel to each other in the longitudinal direction of the cylinder head 2. The distribution oil passage 31 is composed of a strip of distribution oil passage 31.
1.31 are communicated with the support holes 13.13 so as to cross one side of the pair of support holes 13, 13, respectively. Furthermore, as shown in Fig. 4.5, the lubricating oil system L3 also has a lubricating oil passage 32 that extends in the width direction of the cylinder head 2, and a lubricating oil passage 32 that is branched to the left and right so that the cylinder head 2 is parallel to each other in the longitudinal direction. It consists of two distributed lubricating oil passages 33.33 that extend to each bearing of the valve drive camshaft 17 and 18 via a branch lubricating oil passage 34, as shown in FIG. It communicates with the bearing surfaces of 27 and 2B.

As clearly shown in FIG. 5, the bases of the oil supply passage 30 and the lubricating oil passage 32 are connected to a main oil passage 35 which is bored vertically through the cylinder head 2 and which also serves as a through hole for the head bolt 4. The lower end of this main oil passage 35 is communicated with a hydraulic pump (not shown) via a block side oil passage 36 bored in the cylinder block 1. Also, there are first lugs in the middle of the oil supply passage 30 and the lubricating oil passage 32, respectively. Second orifices 37.38 are inserted, and one end surface of these orifices 37.38 engages with a step 39.40 formed in the oil supply passage 30 and the lubricating oil passage 32, respectively, and Positioning is performed by facing the head bolt 4 whose end passes through the main oil passage 35.

Pressurized oil from a hydraulic pump (not shown) passes through the block side oil passage 36 and is divided into the oil supply passage 30 and the lubricating oil passage 32 . The pressure oil that has flowed into the oil supply passage 30 is controlled in flow rate by the first orifice 37, flows through the oil supply passage 30, and is divided into the distribution oil passages 31, 31, and from there to each hydraulic tappet) 10.1
0. Further, the pressure oil that has flowed into the lubricating oil passage 32 is controlled in flow rate by the second orifice 38, flows through the lubricating oil passage 32, is branched into the distribution lubricating oil passage 33.33, and is branched from there into the branch lubricating oil passage 34.34. through the valve train camshaft 17.
18 bearings 27 and 28 are supplied with oil.

Note that the lubricating oil in the lubricating oil passage 32 can also be supplied to other lubricated parts (not shown).

As clearly shown in FIG.
An air bleed plug 41 is inserted into the end upstream of the orifice 37, and a relief valve 42 is inserted into the end of the oil supply path 30 downstream from the first orifice 41. The relief valve 42 includes a piston 44 that opens and closes the relief hole 43, and a valve spring 45 that urges the piston 44 in the direction in which the relief hole 42 is closed.

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

Now, when the pair of valve drive camshafts 17 and 18 are rotated by engine operation, the cam followers 15 and 16 are moved by the hydraulic tappet 10 due to the rotation of the intake and exhaust cams 19 and 20 and the elastic force of the valve springs 21 and 22. The suction/exhaust boat 6.7 is opened and closed at a predetermined timing by swinging up and down about the connecting portion with .10 as a fulcrum and sliding the suction/exhaust valve 8.9 up and down.

Further, a part of the pressure oil from the hydraulic pump driven by the operation of the engine flows from the block side oil passage 36 to the main oil passage 35. The pressurized oil in the main oil passage 35 flows through the first and second orifices 3
7.38, and is divided into an oil supply path 30 and a lubricating oil path 32. The pressure oil in the oil supply channel 30 is diverted to the distribution oil channel 31, 31 and from there is supplied to the hydraulic tappet 10.10 through the support hole 13.13. The hydraulic tappets 1-10.10 are of a conventionally known structure and are operated by receiving pressure oil, and their upper ends are pressed against the base ends of the cam followers 15.16, respectively, so that the above-mentioned valve operating operation is performed smoothly.

Further, the pressurized oil in the lubricating oil passage 32 is distributed to the lubricating oil passage 33.3.
3, from which oil is supplied to bearings 27, 28 of valve drive camshafts 17, 18 through branch oil passages 34, 34.

Therefore, the hydraulic tappen) 10.10 and the valve train camshaft 17.1
The amount of pressure oil supplied to the bearings 27 and 28 of No. 8 is the same as that of No. 1.
The operation of the hydraulic tappet) 10.10 and the bearing 27.2 are individually controlled by the second orifice 37.38.
Lubrication of B is performed efficiently. Also, due to some reason, the oil pressure within the oil supply path 3° becomes excessive, causing the relief valve 4
Even if the pressure inside the oil supply passage 30 is reduced when the bearings 27 and 2 are opened,
8 is supplied with lubricating oil without any problem. Furthermore, the first.
The second orifices 37 and 38 are hydraulic tappets)10.
10 and the bearings 27, 28, pressurized oil can be supplied to the hydraulic tappet 10, 10 and the bearings 27, 28 with less time lag when starting the engine.

C6 Effects of the Invention As is clear from the above examples, according to the present invention,
The cylinder head is equipped with an oil supply system for supplying hydraulic oil to the hydraulic tappet and a lubricant system for supplying lubricant oil to the bearings of the valve drive camshaft, etc. A first and a second orifice for flow rate control are respectively inserted into the first and second orifices. Since the oil supply system and the lubricating oil system are connected in parallel to the main oil passage connected to the hydraulic pressure source on the upstream side of the second orifice, the amount of hydraulic oil to the hydraulic tappet and lubricating oil to the bearing can be controlled. Each can be done separately,
Hydraulic tappet operation and bearing lubrication can be performed efficiently and accurately.

Furthermore, it is now possible to insert the first orifice close to the hydraulic tappet into the oil supply path, and the second orifice close to the bearing into the lubricating oil path, ensuring that the appropriate amount of pressure is applied to the hydraulic tappet and bearing with little time lag even immediately after engine startup. Oil can be supplied quickly and their response is enhanced.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a longitudinal sectional view showing a valve mechanism portion of an engine body equipped with the device of the present invention;
Fig. 2 is a longitudinal sectional view showing the lubricating oil system of the valve camshaft of the engine body, Fig. 3 is a transverse sectional view taken along the line ■-m in Fig. 1, and Fig. 4
The figure is a cross-sectional view along the TV-IV line in Figure 1, and Figure 5 is a cross-sectional view along the line TV-IV in Figure 1.
It is a longitudinal cross-sectional view along the figure VV line. E...Engine body, L...Oil supply system, L2...Lubricating oil system, 2...Cylinder head, 8,9.10...Intake valve as opening/closing valve, exhaust valve, hydraulic tappet , 15.1
6...Cam follower, 17.18...Valve train camshaft,
19°20... Valve cam, 21.22... Valve spring,
27.28...Bearing, 35...Main oil passage, 37.3
8... 1st ° 2nd orifice

Claims (1)

[Claims] A hydraulic tappet is attached to the cylinder head of the engine body, and this hydraulic tappet is connected to the opening/closing valve via a cam follower, and the cam follower swings in relation to the rotation of the valve driving cam on the valve driving cam shaft, and the opening/closing valve is connected to the opening/closing valve. In the valve operating mechanism with a hydraulic tappet that opens and closes the opening/closing valve in cooperation with a valve spring that biases the valve in the valve closing direction, the cylinder head includes a valve mechanism for supplying hydraulic oil to the hydraulic tappet. and a lubricating oil system for supplying lubricating oil to the bearings of the valve drive camshaft, etc., and first and second orifices for flow rate control are inserted in the middle of the oil supply system and the lubricating oil system, respectively. A hydraulic tappet-equipped valve for an internal combustion engine, characterized in that the oil supply system and the lubricating oil system are connected in parallel to a main oil passage connected to a hydraulic source on the upstream side of the first and second orifices. Lubricating device in the mechanism.