JPS6339363Y2 - - Google Patents

Description

[Detailed explanation of the invention] A. Purpose of the invention (1) Industrial application field This invention is for forced lubrication of an OHC type valve train in an internal combustion engine, especially for the cam surface of the valve train cam of the valve train camshaft and the locker arm. This invention relates to a forced lubrication device for the contact surface with the slipper surface.

(2) Conventional technology In the conventional OHC type valve train, the contact surface between the cam surface of the valve train cam, which is integrated with the valve train camshaft, and the slipper surface of the rocker arm that is linked to the intake and exhaust valves, that is, the on-off valve, is lubricated. In cases where an oil bath for supplying oil to the contact surface cannot be formed in the valve drive cam chamber, an oil supply path may be formed on the valve drive camshaft and the oil supply path may be used as a means for supplying oil to the contact surface. lubricate the contact surface.

An oil supply passage is formed in the rocker arm shaft, and the contact surface is supplied with oil from the passage.

A delivery pipe is separately provided, and the contact surface is supplied with oil from the delivery pipe (see Japanese Utility Model Publication No. 4820/1983).

Refueling methods such as the following have been adopted.

However, in the above-mentioned oil supply means, it is difficult to form the oil supply passage of the valve train camshaft with an extremely small inner diameter when mass production workability is taken into consideration. The time required for the contact surface to fill with oil becomes longer, causing a delay in oil supply, and this tendency becomes particularly pronounced in multi-cylinder engines with long valve drive camshafts, resulting in insufficient oil supply to the contact surfaces.

In addition, in the above-mentioned oil supply means, since the valve train camshaft and the rocker arm shaft are arranged at a predetermined distance from each other, the oil jet pressure is low in the low-speed rotation range of the engine, thereby preventing insufficient oil supply to the contact surface. This tendency is particularly strong when the rocker arm shaft is located at a lower position than the valve drive camshaft.

Furthermore, in the above-mentioned means, the delivery tube is specially installed, which increases the number of parts, which causes an increase in costs.

There were several problems, none of which were satisfactory.

(3) Problems that the invention aims to solve The present invention has been made in view of the above-mentioned circumstances. Regardless of the operating condition of the engine, a sufficient amount of lubricating oil can be applied to the cam surface of the valve train cam. Then, make sure to forcibly lubricate the contact surface with the slipper surface of the locking arm.
It is an object of the present invention to provide a forced lubrication device for a valve mechanism in an internal combustion engine, which has a simple structure and is low in cost, which enhances the lubrication effect of the contact surface.

B. Structure of the invention (1) Means for solving the problems According to the invention, in order to achieve the above-mentioned object, the valve drive camshaft is rotatably mounted between the cam case and the cam holder, which are polymerized and bonded on the cylinder head. In a valve drive mechanism for an internal combustion engine, in which a slipper surface of a cam follower for operating an on-off valve is in contact with a cam surface of a valve drive cam that is supported and integrated with the valve drive camshaft, the shaft of the radially outer end of the cam holder is provided. A pair of overhanging arms extending along the axial direction of the valve drive camshaft and tilting away from the shaft are integrally provided on both sides of the direction, and within the overhanging arms, a distribution oil passage and a An oil injection nozzle communicating with the distribution oil passage and opening toward the cam surface of the valve drive cam is provided, and a bolt insertion hole is provided in the cam case and the cam holder adjacent to the journal portion of the valve drive camshaft. A cam case and a cam holder are fixed to the cylinder head by a bolt that is drilled through the cylinder head and screwed into the cylinder head through the bolt insertion hole, and a hydraulic power source is communicated with the distribution oil passage between the bolt insertion hole and the bolt. Forms an oil passage.

(2) Effect According to the above configuration, the pressurized lubricating oil that has reached the distribution oil passage in the extending arm provided in the cam holder is sprayed by the oil injection nozzle to the contact surface between the cam surface of the valve drive cam and the slipper surface of the rocker arm. is injected to provide effective lubrication of the contact surfaces.

(3) Example Next, an example of the present invention will be described. A V-type multi-cylinder internal combustion engine has two cylinder rows C ₁ and C ₂ arranged in a V-shape. Since both cylinder rows C ₁ and C ₂ have the same structure, one cylinder row will be explained below.
Let me explain about _C1 .

A cylinder head 3 is connected via a gasket 4 to a cylinder block 2 in which a plurality of cylinders 1 are arranged side by side.
A cam case 15 is polymerically bonded onto the cylinder head 3, and a head cover 16 is further mounted on the cam case 15. The cylinder head 3, cam case 15 and head cover 16 constitute an engine head Eh.

A piston 5 interlocked with a crankshaft (not shown) is slidably fitted into the cylinder 1 of the cylinder block 2, and the cylinder head 3 has a combustion chamber 6 facing the top surface of the piston 5 and a combustion chamber 6. A pair of intake ports 8, 8 and a pair of exhaust ports 9, 9 are opened in the ceiling wall 7 of the vehicle. Further, in the cylinder head 3, a pair of intake valves 10, 10 for opening and closing the intake ports 8, 8 and a pair of exhaust valves 11, 11 for opening and closing the exhaust port 8 are provided with valve guides 12, 12 and 13, 13, respectively. It is slidably supported through. The intake valves 10, 10 and the exhaust valves 11, 11 are provided with valve springs 19, 19; 20, 2 that bias them to close, respectively.
0 is set.

Further, the cylinder head 3 is provided with an ignition plug 14 whose electrode faces the combustion chamber 6.

On the cylinder head 3, the cam case 15
A valve operating mechanism 18 that operates the pair of intake valves 10, 10 and exhaust valves 11, 11 is provided within a valve operating cam chamber 17 defined by the head cover 16 and the intake valve 10, 10, and the exhaust valve 11, 11.

Next, the structure of this valve mechanism 18 will be explained.

Almost directly above the intake valves 10, 10, there is a single valve drive camshaft 21 that is interlocked with a crankshaft (not shown).
are arranged along the arrangement direction of the cylinders 1. A plurality of journal parts 2 of the valve train camshaft 21
1j... (Fig. 2) shows a plurality of bearing stands 15a... formed on the cam case 15, and bolts 2 on them.
It is rotatably held by cam holders 24 . . . which are fixed by cam holders 2 and 23 .

As clearly shown in FIG. 2, the valve drive camshaft 21 has a pair of intake cams 21i, 21i and 21i, corresponding to the intake valves 10, 10 and exhaust valves 11, 11, between the journal parts 21j... The exhaust cams 21e, 21e are integrally formed, and the intake cam 2
1i, 21i are arranged adjacent to and on both sides of the cam holder 24, and exhaust cams 21e, 21e
are further placed on both sides.

As shown in FIG. 1, the intake cams 21i, 21i
A pair of first cam followers 25, 25 are interposed between the intake valves 10 and the stem ends of the intake valves 10, 10. The first cam followers 25, 25 are provided with an adjustment bolt 26 at each base end, and a spherical end 26a at the tip of the adjustment bolt 26 is connected to a spherical recess 27 of a support bolt 27 screwed into the cylinder head 3.
is rotatably engaged with a. Further, the slipper surface 25a formed on the upper surface of the first cam follower 25 is
The resilient force of the valve spring 19 causes the intake cam 21i to come into contact with the cam surface of the intake cam 21i.

As clearly shown in FIG.
and the second support shafts 28 and 29 are respectively bolts 2
2, 30, and both supporting shafts 28, 2
9 is arranged parallel to the valve drive camshaft 21. The first support shaft 28 near the intake valves 10, 10 swingably supports a pair of second cam followers 31, 31, and the second support shaft 29 near the exhaust valves 11, 11 supports the pair of second cam followers 31, 31 in a swingable manner.
A pair of bell crank type rocker arms 33, 33 are swingably supported. These second cam followers 3
A pair of push rods 34, 34 are interposed between the opposing surfaces of the rocker arms 33, 33. The slipper surfaces 31a, 31a formed on one side of the pair of second cam followers 31, 31 are formed on the cam surfaces of the intake cams 21i, 21i, so that the valve spring 2
The proximal ends of the rocker arms 33, 33 are engaged with the stem ends of the exhaust valves 11, 11 via adjustment bolts 32 screwed thereon.

Next, the cam surfaces of the intake cams 21i, 21i,
Slipper surface 25 of first cam follower 25, 25
a, the contact surface with 25a and the exhaust cam 21
e, 21e cam surface and the second cam follower 31,
To explain the oil supply system for forcibly supplying lubricating oil to the contact surfaces with the slipper surfaces 31a and 31a of the cam holder 24, the valve drive camshaft 21 A pair of overhanging arms 24a, 24a are integrally provided along the axial direction of the axis 21 and extending obliquely in a direction away from the axis 21, and inside these overhanging arms 24a, 24a,
Distribution oil passages 35, 35 are bored in the longitudinal direction,
The open ends of these distribution oil passages 35, 35 are sealed with blind plugs. The pair of overhanging arms 24a, 2
A plurality of oil injection nozzles 36, 37;
are drilled, and their oil injection nozzles 36, 37;
Nozzles 6 and 37 are directed toward the cam surfaces of the intake cams 21i, 21i and the exhaust cams 21e, 21e, respectively. Bearing stand 1 of the cam case 15
5a and the cam holder 24, bolt insertion holes 38, 39 are formed therethrough in the vicinity of the journal portion 21j of the valve drive camshaft 21. 39
An annular oil passage 40 is formed between the mounting bolt 22 and the mounting bolt 22 which is inserted into the cylinder head 3 and fastened to the cylinder head 3. The upper end of this oil passage 40 is connected to the pair of distribution oil passages 35, 35. will be communicated to. The lower end of the oil passage 40 communicates with an oil supply passage 41 formed between the cylinder head 3 and the bearing stand 15a of the cam case 15, and this oil supply passage 41 is connected to the discharge side of a hydraulic pump (not shown). It is equipped with pressurized lubricating oil. Further, a branch oil passage 42 is branched from the oil supply passage 41, and an end of this branch oil passage 42 is opened to the bearing surface of the bearing stand 15a.

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

If the valve train camshaft 21 is now rotated by engine operation, the intake valves 10, 10 are rotated via the first cam followers 25, 25, and the second cam followers 3 are rotated.
1, 31, push rods 34, 34, and rocker arms 33, 33, the exhaust valves 11, 11 are opened and closed at predetermined timings, respectively, and the valve operating mechanism 18 is operated.

Further, pressurized lubricating oil from a hydraulic pump (not shown), which is driven by engine operation, flows from an oil supply path 41 into an oil passage 40 and a branch oil path 42 formed in the bolt holes 38 and 39. The lubricating oil flowing through the oil passage 40 is transmitted through the extending arms 24a and 2 formed on the cam holder 24.
4a, the oil flows into the distribution oil passages 35, 35 in the oil injection nozzles 36, 37;
e is injected toward the cam surfaces of the cam surfaces and the first and second cam followers 25, 25;
1, 31 slipper surfaces 25a, 25a; 31a,
Lubricate the contact surface with 31a. Furthermore, the lubricating oil that has flowed into the branch oil passage 42 is supplied to the bearing surface of the bearing stand 15a, and is supplied to the journal portion 21j of the valve drive camshaft 21.
Lubricate...

C. Effects of the invention As described above, according to the invention, in the valve operating mechanism of an internal combustion engine, a pair of overhang arms are integrally extended on both sides in the axial direction of the radially outer end of the cam holder fixed to the cam case. Since a distribution oil passage and an oil injection nozzle are provided on the extending arm, the contact surface between the cam surface of the valve train cam and the slipper surface of the cam follower can be effectively forcedly lubricated, and when the engine is started at a low temperature, Even when rotating at low speeds, there will be no lubrication delay or lack of lubrication.

Furthermore, since the pair of overhanging arms are integrally formed with the cam holder, the lubrication system can be formed simply by fixing the cam holder to the cam case.
Compared to conventional systems that require a separate lubrication pipe, the number of parts is reduced, the ease of assembly is improved, costs can be significantly reduced, and the valve mechanism as a whole can be made more compact.

Further, the pair of overhanging arms extend from both sides in the axial direction of the radially outer end of the cam holder along the axial direction of the valve drive camshaft and at an angle in a direction away from the shaft. The part of the cam holder that is fixed to the cam case can be moved closer to the center of the valve drive cam, ensuring high fixation strength to the cam case while maintaining the desired lubricant injection distance between the extending arm and the valve drive cam. This allows the lubrication to be performed more efficiently, and there is no fear of interference between the overhanging arm and the valve drive cam.Furthermore, by slanting the overhang arm, the length in the axial direction of the valve drive cam can be shortened, and the cam surface can be improved. It is possible to reliably inject oil into the valve mechanism, and the overhanging arm does not increase the size of the valve mechanism or interfere with its layout.

In addition, a bolt insertion hole is formed in the cam case and cam holder adjacent to the journal part of the valve drive camshaft, and the cam case and cam holder are fixed to the cylinder head by the bolt insertion hole and the bolt, and the bolt insertion hole and the bolt are fixed to each other by the bolt insertion hole and the bolt. In addition, an oil passage communicating the hydraulic pressure source with the distribution oil passage is formed, so that the fixed portion at the outer end of the cam case and cam holder is close to the valve drive camshaft to prevent the cam case and cam holder from sticking to the cylinder head. It is strong, the surface pressure between them is high, and lubricating oil does not leak. Furthermore, since the bolt insertion hole can be used as an oil passage, the structure of the lubrication system can be simplified.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention. Figure 1 is a partially longitudinal side view of a V-type multi-cylinder internal combustion engine in which the present invention is implemented, and Figure 2 is a partially enlarged view of the engine head excluding the head cover. 3 is a sectional view taken along the line shown in FIG. 2, FIG. 4 is a bottom view of the cylinder head, FIG. 5 is a vertical sectional side view of the cam holder, and FIG.
FIG. 3 is a bottom view of the cam holder along a line. 10, 11...Suction and exhaust valves, 15...Cam case, 15a...Bearing stand, 16...Head cover,
21...Valve drive camshaft, 21i, 21e...Suction and exhaust cams, 24a...Extended arm, 25...First cam follower, 25a...Slipper surface, 31...Second cam follower, 31a...Slipper surface , 35... distribution oil passage, 36, 37... oil injection nozzle.

Claims (1)

[Scope of utility model registration request] A valve drive camshaft 21 is disposed between a cam case 15 and a cam holder 24, which are superimposed and bonded on the cylinder head 3.
The on-off valve 1 is rotatably supported on the cam surface of the valve cam 21i, 21e that is integral with the valve camshaft 21.
In a valve train for an internal combustion engine in which the slipper surfaces 25a and 31a of the cam followers 25 and 31 for operation 0 and 11 are in contact with each other, a valve train camshaft is connected to both sides of the radially outer end of the cam holder 24 in the axial direction. A pair of overhanging arms 24a extending along the axial direction of the shaft 21 and extending in a direction away from the shaft 21 at an angle.
are integrally extended, and a distribution oil passage 3 is provided in the extending arm 24a.
5, and oil injection nozzles 36 and 37 that communicate with the distribution oil passage 35 and open toward the cam surfaces of the valve operating cams 21i and 21e, and further include the cam case 1.
5 and the cam holder 24, the valve drive camshaft 2
Bolt insertion holes 38, 39 are bored through the journal portion 21j of No. 1, and the bolt insertion holes 38,
The cam case 15 and cam holder 24 are fixed to the cylinder head 3 by bolts 22 screwed into the cylinder head 3 through 39, and a hydraulic source is connected to the distribution oil passage 35 between the bolt insertion holes 38, 39 and the bolt 22. A forced lubrication device for a valve mechanism in an internal combustion engine, characterized in that a communicating oil passage 40 is formed.