JPH10131730A - Oil dropper in internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent the leakage of oil, the deterioration of oil and the decrease in oil pressure without increasing the number component items when the oil of a valve mechanism chamber in a cylinder head flows down to an oil pan through chain cases for housing a timing chain between a crank shaft and cam shafts. SOLUTION: An oil spill hole 20 for flowing oil in a valve mechanism chamber into chain cases 12 and 13 is located at a position outside the upper end part of a chain guide member 18 vertically extending along the longitudinal direction of a timing chain 11. Thus, the oil from the oil spill hole 20 is made to flow down to a part outside the chain guide member 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil dropping device for guiding an oil after lubricating a valve mechanism on an upper surface of a cylinder head to an oil pan in an internal combustion engine.

[0002]

2. Description of the Related Art Japanese Patent Laid-Open No. 7-28650 as prior art
No. 8 discloses that a crankshaft in a cylinder block and a camshaft in a cylinder head protrude from one end surface of the cylinder block and the cylinder head, and a timing chain is wound therebetween, while being wound on one end surface of the cylinder block and the cylinder head. In an internal combustion engine provided with a chain case for accommodating the timing chain, an inner bottom of the valve mechanism chamber and the inside of the chain case are provided on a partition wall of the cylinder mechanism between the valve mechanism chamber and the chain case. After drilling a communicating oil release hole and lubricating the valve operating mechanism in the valve operating mechanism, the oil flows out of the oil releasing hole into the chain case, and then passes through the chain case to form the cylinder. Suggests to lead to an oil pan at the bottom of the block.

[0003]

However, in this prior art, the oil that has flowed out of the oil escape hole into the chain case is partially or partially forwarded to the timing chain rotating in the chain case. After being attached and being shaken off from the timing chain toward the inner surface of the chain case, it will flow down along the inner surface of the chain case, so that the degree of oil contact with the air is high and foaming occurs. Become. As a result, there is a problem that the oil pressure may be reduced, and the oil deteriorates quickly.

The present invention focuses on the fact that a chain guide member is provided within the chain case for tensioning or swaying the timing chain.
It is an object of the present invention to solve the above-mentioned problem by using this.

[0005]

In order to achieve this technical object, the present invention relates to a method of "wrapping around one end surface of a cylinder block and a cylinder head between a crank shaft of a cylinder block and a cam shaft of a cylinder head. A chain case for accommodating the timing chain is provided, and a chain guide member for the timing chain is provided in the chain case so as to extend in a vertical direction along the timing chain. And an oil escape hole from the inner bottom of the valve mechanism chamber into the chain case is formed in a partition wall between the oil escape hole and the chain case. Flow down the outer portion of the chain guide member. Located outside the portion at the upper end of the de member. And the configuration called ".

[0006]

Operation and effect of the present invention
By utilizing the chain guide member originally provided in the timing chain, the amount of oil flowing out of the oil escape hole into the chain case and adhering to the rotating timing chain can be significantly reduced. It is possible to prevent oil leakage from the chain case and to reliably prevent a decrease in oil pressure without complicating the structure, and it is possible to surely prevent oil deterioration. .

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In this figure, reference numeral 1 denotes a cylinder block provided with an oil pan (not shown) at a lower portion, and reference numeral 2 denotes a cylinder head fastened to the upper surface of the cylinder block 1.

A crankshaft 3 is supported by the cylinder block 1, while a camshaft 4 for an intake valve and a camshaft 5 for an exhaust valve are supported on an upper surface of the cylinder head 2. And a valve mechanism chamber 6 for accommodating a valve mechanism (not shown) for opening and closing an intake valve and an exhaust valve with the two camshafts 4 and 5. 6
The head cover 7 is detachably mounted.

A small-diameter sprocket 8 in which the crankshaft 3 projects from one end of the cylinder block 1 and a large sprocket 8 in which both camshafts 4 and 5 project from one end of the cylinder head 2. A timing chain 11 for transmitting the rotation of the crankshaft 3 to both camshafts 4 and 5 is wound between the sprockets 9 and 10 having the same diameter.

A chain case 12 for covering the timing chain 11 is detachably attached to one end surface of the cylinder block 1, while one end surface of the cylinder head 2 and one end surface of the head cover 7 are Chain cases 13 and 14 that cover the timing chain 11 are provided integrally. A portion of the outer peripheral surface of the timing chain 11 between the crankshaft 3 and the intake valve camshaft 4 is in contact with a tension chain guide member 15 formed in a vertically long arc shape. The lower end of the chain guide member 15 is rotatable with respect to the cylinder block 1 by a pin 16.
When the timing chain 11 is pressed by the tensioner mechanism 17 against the timing chain 11 in a state where the timing chain 11 is pivoted, the timing chain 11 is maintained in a tensioned state by a predetermined tension.

A portion of the outer peripheral surface of the timing chain 11 between the crankshaft 3 and the cam shaft 5 for exhaust valve is formed to extend vertically along the timing chain 11, Is attached to the one end surface of the cylinder block 1 or one end surface of the cylinder head 2 by fastening bolts 19 to the chain guide member 18. Thus, the timing chain 11 is prevented from swinging.

Further, a partition wall 2a of the cylinder head 2 between the valve mechanism chamber 6 and the chain case 13 has an oil escape hole 20 communicating the inner bottom of the valve mechanism chamber 6 and the inside of the chain case 13. After the oil after lubricating the valve operating mechanism in the valve operating mechanism 6 flows out from the oil release hole 20 into the chain case 13, the chain in the chain case 13 and the cylinder block 1 is removed. It is configured to pass through the inside of the case 12 and to the oil pan below the cylinder block 1.

The oil release hole 20 is located at an outer portion of the upper end of the chain guide member 18. As described above, by locating the oil escape hole 20 from the valve mechanism chamber 6 into the chain case 13 at the outer portion at the upper end of the chain guide member 18, the oil escape hole 20 enters the chain case 13 from the oil escape hole 20. Since the outflowing oil flows down the outer portion of the chain guide member 18, it is determined that the oil adheres to the rotating timing chain 11 by the chain guide member 18 originally provided in the timing chain 11. By using, you can greatly reduce.

In this case, the cross section of the chain guide member 18 is, as shown in FIG.
a and a plate portion 18b parallel to one end face.
By forming it in the shape of a letter, the portion between the plate portion 18a perpendicular to the one end surface and the plate portion 18b parallel to the one end surface, and the one end surface is vertically moved along the outside of the chain guide member 18. Because it can form a passage that extends
The effect of preventing oil from adhering to the timing chain 11 from the oil escape hole 20 can be further promoted.

In order to prevent oil from adhering to the timing chain 11, the tension chain guide member 15 may be used instead of using the steady-state chain guide member 18 as described above. Needless to say.

[Brief description of the drawings]

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

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along line III-III of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylinder block 2 Cylinder head 2a Partition wall 3 Crankshaft 4,5 Camshaft 6 Valve mechanism room 7 Head cover 11 Timing chain 12,13,14 Chain cover 15 Chain guide member for tensioning 18 Chain guide member for steady rest 20 Oil escape Hole

Claims (1)

[Claims] 1. A chain case for accommodating a timing chain wound between a crank shaft of a cylinder block and a cam shaft of a cylinder head is provided on one end surface of a cylinder block and a cylinder head. A chain guide member for the timing chain is provided so as to extend in the vertical direction along the timing chain, and further, a partition wall of the valve head mechanism chamber and the chain case in the cylinder head includes an inner part of the valve mechanism chamber. An internal combustion engine having an oil escape hole from the bottom into the chain case, wherein the oil escape hole is formed so that oil from the oil escape hole flows down an outside portion of the chain guide member. It is located at the outer part at the upper end of the guide member. Oil removing device in an internal combustion engine.