JPH07279637A - Valve system lubricating device of internal combustion engine - Google Patents

Abstract

PURPOSE:To surely lubricate a sliding part between a valve bridge and a guide member by providing an oil sump part in the vicinity of a connecting part between the guide member and a cylinder head, and dipping the sliding part in oil of the oil sump part. CONSTITUTION:When power is transmitted to a valve bridge 6 by a power transmitting means, plural valves 9 are driven to open and close interlocking with the valve bridge 6. An oil sump part is provided in the vicinity of a connecting part between a guide member 7 and a cylinder head 1. When the lower end of the sliding part of the valve bridge 6 to the guide member 7 most approaches the cylinder head 1, it reaches a position nearer the cylinder head 1 than the uppermost surface of the oil sump part, so that the lower end of the sliding part is dipped in oil. accumulated in the oil sump part. Oil which adhered at that time is carried away when the sliding part next gets away from the cylinder head 1 to be supplied to the sliding part. Thus, the sliding part between the valve bridge and the guide member can be surely lubricated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve train lubricating system for an internal combustion engine.

[0002]

2. Description of the Related Art Generally, in a valve operating system for an internal combustion engine, as shown in Japanese Utility Model Laid-Open No. 62-710, a push rod is pushed up by a cam, and a rocker arm which rolls around a rocker shaft is interlocked with a cap to insert the rocker arm. The valve bridge fitted to the guide pin and the valve in contact therewith are pushed down against the valve spring. When the engine rotates, oil is sucked up from the oil pan by an oil pump (not shown), and circulates in the entire engine to lubricate the sliding surfaces between the components of the engine. This oil is also supplied to valve train components. 2. Description of the Related Art Conventionally, in such a valve operating system for an internal combustion engine, as shown in FIG. 2, a part of the oil sucked from the oil pan and circulated by an oil pump (not shown) is formed in an oil passage formed inside the rocker shaft 11. 11a, a part of which goes out from a hole 11b formed in the rocker shaft 11 to lubricate the sliding surface between the rocker shaft 11 and the rocker arm 4, and the remaining oil is further passed through an oil passage formed in the rocker arm 4. 4a, through a hole 4b formed in the rocker arm 4 and traveling along the surface of the rocker arm 4,
When this oil reaches the surface of the valve bridge 6 after lubricating the contact surface between the cap 5 and the valve bridge 6, the oil further propagates along the surface of the valve bridge 6 and the surface of the valve bridge 6 and the guide hole 6a of the valve bridge. Into the communication hole 6b. The oil in the communication hole 6b lubricated the sliding surface between the guide pin 7 and the valve bridge 6.

[0003]

However, in the above-mentioned prior art, the oil discharged from the outlet of the oil passage formed in the rocker arm to the outside is sucked up by the oil pump from the oil pan by the rotation of the engine. Since the oil has been circulated, the degree of dispersion of the oil when it is discharged from the outlet of the oil passage, the oil temperature,
The hydraulic pressure largely depends on the operating condition of the engine. That is, when the engine rotational speed is low, the rotational speed of the crankshaft is also low, and therefore the drive speed of the valve train system component that is linked to the crankshaft is naturally low. However, as the engine speed increases, the drive speed of the valve train components also increases, so the degree of dispersion of the oil discharged from the outlet of the oil passage formed in the rocker arm to the outside with the vigorous movement of the valve bridge, It may become extremely large and may not reach the surface of the valve bridge. Further, when the engine is just started, the oil temperature is remarkably low and the viscosity thereof is extremely large as compared with the time when a sufficient time has passed since the engine was started. On the contrary, when the engine is operated for a long time, the oil temperature is considerably high and its viscosity is extremely low. If the viscosity of the oil is different as described above, naturally, the scattering degree when the oil is discharged from the outlet of the oil passage provided in the rocker arm is also different. Even if the oil travels on the surface of the valve bridge, if the viscosity of the oil is different, the amount of oil supplied into the hole provided near the guide member of the valve bridge is also different. Further, since the oil pressure of the oil is low when the engine speed is low, the pressure of the oil when it is discharged to the outside from the outlet of this oil passage through the oil passage provided in the rocker arm is also small. Therefore, there is a possibility that the oil will not be properly discharged to the outside. Further, since the oil pressure is high when the engine speed is high, the pressure of the oil when it is discharged to the outside from the outlet of this oil passage through the oil passage provided in the rocker arm also becomes large. Therefore, the degree of oil scattering may be significantly increased. As described above, the degree of dispersion of oil, the oil temperature, and the oil pressure when discharged from the outlet of the oil passage largely depend on the operating state of the engine.Therefore, a certain amount of oil is not always provided near the guide member of the valve bridge. There is a problem that the amount of oil supplied to this portion is not always stable and the sliding portion between the valve bridge and the guide member is not reliably lubricated. The present invention solves the above problems by eliminating the fluctuation of the oil supply amount depending on the engine state.

[0004]

The structure of the present invention comprises a valve bridge provided so as to be capable of contacting a plurality of valves and power transmission means for transmitting power to the valve bridge. When power is transmitted to the valve bridge by the means, the plurality of valves are opened / closed in conjunction with the valve bridge, and a guide member for guiding the valve bridge is provided on a cylinder head of an internal combustion engine. In the valve gear, an oil reservoir is formed near a connecting portion between the guide member and the cylinder head by a recess capable of retaining a predetermined amount of oil, and the guide member of the valve bridge is driven when the plurality of valves are opened and closed. When the lower end of the sliding part of the and the closest to the cylinder head, the sliding part is from the uppermost surface of the oil sump part. It is a valve train lubrication system for an internal combustion engine, characterized in that said oil reservoir portion is formed so as to reach a position closer to the cylinder head.

[0005]

[Operation] When power is transmitted to the valve bridge, this power is transmitted to a plurality of valves, which are opened and closed. When the valves are opened, intake air is sent into the combustion chamber of the engine and exhaust gas is discharged from the combustion chamber. When the valve is taken out or closed, the intake air is blocked from entering the combustion chamber, and the exhaust gas is blocked from flowing out from the combustion chamber. At this time, the valve bridge moves in the opening / closing driving direction of the plurality of valves, and the sliding portion with the guide member slides along the guide member.
According to the present invention, the oil sump portion is provided in the vicinity of the connecting portion between the guide member and the cylinder head, and the lower end of the sliding portion of the guide member of the valve bridge that moves in the opening / closing driving direction of the plurality of valves is the lowest. When it approaches the cylinder head, it reaches a position closer to the cylinder head than the uppermost surface of the oil sump, so the lower end of this sliding part is immersed in the oil accumulated in the oil sump, and the oil that adheres at this time is Next, when the sliding portion moves away from the cylinder head, it is taken away and supplied to the sliding portion.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a cylinder head, 2 is a valve lifter, 3 is a push rod, 4 is a rocker arm, 5 is a cap, 6 is a valve bridge, 7 is a guide pin, 8 is a valve guide, 9 is a valve, 10 is a valve spring,
11 is a rocker shaft. The cylinder head 1 is located on the upper surface of a cylinder block (not shown), and has a recess on the lower surface thereof to form a combustion chamber together with the cylinder block described above. The valve lifter 2 is one of the valve train components, and the valve 9 is an OHV provided on the cylinder head 1 side.
In the engine, it is located between a cam (not shown) and the push rod 3 and has a cylindrical shape. The push rod 3 is a push rod that transmits the movement of the valve lifter 2 driven by the above-mentioned cam to the rocker arm 4. The rocker arm 4 is located between the push rod 3 and the cap 5 and converts the lift of the cam described above into the lift of the valve 9. The cap 5 is located between the rocker arm 4 and the valve bridge 6, and constitutes a contact portion between the rocker arm 4 and the valve bridge 6. The valve bridge 6 includes a plurality of valves 9
It is bridged between a plurality of valves 9 so as to be driven by one cam. The guide pin 7 is the valve bridge 6
Is fitted in a cylindrical hole 6a provided between the respective valves, and guides the valve bridge 6 so that the movement direction of the valve bridge 6 coincides with the opening / closing direction of the valve 9. This is to prevent displacement of the bridge. The valve guide 8 guides the valve 9, and is press-fitted and fixed to the cylinder head 1. The valve 9 moves up and down in the figure to suck air into the combustion chamber and discharge exhaust gas from the combustion chamber. The valve spring 10 is a biasing means that biases the valve 9 in the valve closing direction, and is composed of a coil spring. Piano wire and Si-Cr oil tempered wire are mainly used as materials. The rocker shaft 11 is slidably fitted in a through hole 4c provided in the rocker arm 4 and is provided as a rolling shaft of the rocker arm. When the engine starts, a crankshaft (not shown) rotates, and the above-mentioned cam that interlocks with the crankshaft also rotates. The power of the cam lifts the valve lift 2, push rod 3, rocker arm 4, cap 5, The valve bridge 6 and the valve 9 are transmitted in this order, and the valve 9 moves up and down in the figure to open and close to supply intake air to the combustion chamber and exhaust exhaust gas from the combustion chamber. To do When the engine starts, oil is sucked up from an oil pan (not shown) by an oil pump (not shown) and circulates in the entire engine to lubricate the sliding surfaces between the components that make up the engine. It is also supplied to system parts. A part of this oil passes through an oil passage 11a formed inside the rocker shaft 11, and a part of it goes out from a hole 11b formed in the rocker shaft 11 to lubricate the sliding surface between the rocker shaft 11 and the rocker arm 4. Further, the remaining oil further passes through the oil passage 4a formed in the rocker arm 4, exits from the hole 4b formed in the rocker arm 4, and travels on the surface of the rocker arm 4, and this oil flows between the cap 5 and the valve bridge 6. After reaching the surface of the valve bridge 6 after lubricating the contact surface,
A hole 6b that extends along the surface of the valve bridge 6 and connects the surface of the valve bridge 6 and the guide hole 6a of the valve bridge.
to go into. The oil that has entered this hole 6b is the cylinder head 1
Lubricate the sliding surface between the guide pin 7 and the valve bridge 6, which is press-fitted into the. The oil that has propagated on the surface of the valve bridge 6 is stored in the oil storage portion 1a formed over the outer periphery of the press-fitting portion of the guide pin 7 of the cylinder head 1. The valve bridge 6 moves in the opening / closing driving direction of the valve 9 in accordance with the movement of the cam described above, and when the valve 9 is closest to the cylinder head 1, the guide pin 7 of the valve bridge 6 is engaged with the guide pin 7. The lower part of the hole 6a is immersed in the oil reservoir 1a formed in the cylinder block 1. As the guide hole 6a of the valve bridge 6 moves up and down, the oil attached to the lower part of the guide hole 6a formed in the valve bridge 6 is supplied to the sliding surface between the valve bridge 6 and the guide pin 7. In addition, in this embodiment, the oil that has propagated on the surface of the valve bridge 6 is stored in the oil reservoir 1a. In this oil reservoir 1a, the oil scattered in the upper space of the cylinder head 1 or the upper surface of the cylinder head 1 is Only the flowing oil may be stored, and in this case, the positive oil flow passage from the oil passage 11a to the oil reservoir 1a such as the oil passage 4a and the communication hole 6b may be eliminated. Further, it is needless to say that the present invention is not limited to the present embodiment and various modes can be considered without departing from the spirit of the present invention. For example, the hole for the valve spring seat may be used as an oil reservoir.

According to the present invention, the oil sump is provided in the vicinity of the connecting portion between the guide member and the cylinder head, and slides on the guide member of the valve bridge which moves in the opening / closing driving direction of the plurality of valves. When the bottom end of the sliding part reaches the position closest to the cylinder head when it comes closest to the cylinder head, the bottom end of this sliding part is immersed in the oil that has accumulated in the oil collecting part. The adhered oil is then carried away when the sliding portion moves away from the cylinder head, and is supplied to the sliding portion. As a result, there is an excellent effect that the sliding portion between the valve bridge and the guide member is surely lubricated.

[Brief description of drawings]

FIG. 1 is an overall view showing an embodiment of the present invention.

FIG. 2 is an overall view showing a conventional technique.

[Explanation of symbols]

 1 ... Cylinder head 1a ... Oil reservoir 2 ... Valve lifter 3 ... Push rod 4 ... Rocker arm 4a ... Oil passage 4b ... Hole 4c ... Through hole 5 ... Cap 6 ・ ・ ・ Valve bridge 6a ・ ・ ・ Guide hole 6b ・ ・ ・ Communication hole 7 ・ ・ ・ Guide pin 8 ・ ・ ・ Valve guide 9 ・ ・ ・ Valve 10 ・ ・ ・ Valve spring 11 ・ ・ ・ Rocker shaft 11a ・..Oil passages 11b ... holes

Claims (1)

[Claims] 1. A valve bridge provided so as to be capable of contacting a plurality of valves, and a power transmission means for transmitting power to the valve bridge. The power transmission means transmits power to the valve bridge. Then, the plurality of valves are opened / closed in conjunction with the valve bridge, and a guide member for guiding the valve bridge is provided on a cylinder head in a valve operating system for an internal combustion engine, wherein the guide member and the guide member are provided. An oil reservoir is formed by a recess capable of retaining a predetermined amount of oil in the vicinity of the connecting portion with the cylinder head, and the lower end of the sliding portion of the valve bridge with the guide member is the most when the plurality of valves are opened and closed. When approaching the cylinder head, the sliding part is located closer to the cylinder head than the uppermost surface of the oil reservoir. Valve train lubrication system for an internal combustion engine, wherein the oil reservoir is formed so as to.