JPH074809U - Lubrication structure of valve train - Google Patents

Abstract

(57) [Abstract] [Purpose] The optimum lubricating oil is supplied to a valve train that transmits power between an intake valve and an exhaust valve of an internal combustion engine and a cam shaft to prevent wear of a contact portion. In a valve train using the rocker arm shaft 2 with the shaft center of the lubricating oil passage 2a, a lubricating oil passage 2a of the rocker arm shaft 2 is provided.
The rocker arm oiling hole 2b and the oil hole 1b to be discharged to the outside of the rocker arm 1 are provided at a deviated position with a certain distance, and the rocker arm oiling hole 2b and the oil hole 1b are
Minute groove 1c provided on rocker arm or rocker arm shaft
Connected in (2c).

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a lubricating structure for a valve train that transmits power between an intake valve and an exhaust valve of an internal combustion engine and a cam shaft.

[0002]

[Prior art]

 Conventionally, an intake valve and an exhaust valve are housed and arranged in the cylinder head of an internal combustion engine, and the valve stem of the intake valve and the exhaust valve is slid up and down via the tappet, push rod, and rocker arm (valve arm) by rotating the cam shaft. The rocker arm is designed to open and close, and the rocker arm discharges lubricating oil from the oil hole provided in the rocker arm shaft to lubricate the sliding parts and bearing parts of the rocker arm, valve stem, push rod, etc. Of. For example, it is the technique disclosed in Japanese Utility Model Publication No. 63-45526.

[0003]

[Problems to be solved by the device]

 With such a conventional lubrication configuration, the amount of lubricating oil discharged is determined by the oil clearance, so when the temperature of the lubricating oil is low, such as during startup, it is difficult for the lubricating oil to come out of the oil holes, and intermittent lubrication is also possible. There is also a method to connect the holes to the jet of lubricating oil, but when the lubricating oil temperature rises, the discharge amount becomes too large and the following problems occur. In other words, if the discharge amount is too large, it is difficult to separate the blow-by gas and the lubricating oil from the breather, and there is also a lot of oil down from the valve stem, causing the lubricating oil to burn at the valve seat and burning deposits between the seat and the valve. There was a case where it was not possible to reliably suck and exhaust air because it was sandwiched between. Also, if the amount of lubrication is too small, the valve and valve guide will wear, and the push rod will also wear.

[0004]

[Means for Solving the Problems]

 The present invention is configured as follows to solve the above problems. In other words, in a valve operating system that uses the rocker arm shaft axis as the lubricating oil passage, the rocker arm lubrication hole that communicates with the lubricating oil passage of the rocker arm shaft and the oil hole that discharges to the outside of the rocker arm are provided at certain positions with a gap. The rocker arm oiling hole and the oil hole are connected by a micro groove provided on the rocker arm or the rocker arm shaft.

[0005]

[Action]

 By using such means, the lubricating oil from the lubricating oil passage 2a lubricates the pivotal support part with the rocker arm 1 through the rocker arm oiling hole 2b, and reaches the minute groove 1c (2c) through the rocker arm oiling hole 2b. The pressure oil is squeezed and blown from the oil hole 1b onto the boss portion 1a of the rocker arm 1 to lubricate the valve stem, the push rod and the like.

[0006]

【Example】

 The problems to be solved and the means for solving the problems of the present invention are as described above, and the configuration of the embodiment will be described with reference to the attached drawings. 1 is a side view of a rocker arm having a lubricating structure according to the present invention, FIG. 2 is a plan view of the same, FIG. 3 is a sectional view taken along the line AA in FIG. 1, and FIG. 4 is an enlarged sectional view taken along the line BB in FIG. 5 is an enlarged sectional view taken along the line CC of FIG. 3, FIG. 6 is an enlarged sectional view taken along the line DD of FIG. 3, FIG. 7 is a side view of a rocker arm having another lubricating structure, and FIG. It is a -E sectional view.

In FIGS. 1 and 2, a rocker arm 1 is housed in a cylinder head on a cylinder block, and the rocker arm 1 is rotatably supported by a rocker arm shaft 2 which is horizontally mounted on the cylinder head, so that the rocker arm 1 is rotatably supported. The adjust bolt 3 is screwed on one end and fixed by a lock nut 4 so that the position can be adjusted, the lower end of the adjust bolt 3 is brought into contact with the tip of a push rod (not shown), and the other end of the push rod is passed through a tappet. The cam shaft is configured to be brought into contact with a cam on the cam shaft so that the cam shaft rotates in synchronization with the crank shaft.

The lower end of the rocker arm 1 is in contact with a stem end 5 a of a valve stem 5, and the valve stem 5 is formed on a cylinder head by externally fitting a valve spring (not shown). A valve head (not shown) is formed in the lower part of the valve stem 5 inserted into the valve guide, and is brought into contact with a valve seat fitted in an intake hole or an exhaust hole opened in the cylinder head. In such a configuration, the cam shaft is rotated by the rotation of the crank shaft, the rocker arm 1 reciprocally rotates like a seesaw through the push rod, and the valve stem 5 is pushed to open and close the valve.

Further, as shown in FIG. 3, an oil passage 2a is formed in the shaft center of the rocker arm shaft 2 to form a pipe shape, and a rocker arm 1 pivotal support portion of the rocker arm arm shaft 2 is illustrated in FIG. As shown in FIGS. 4 to 6, a rocker arm lubrication hole 2b is opened through the oil passage 2a in the radial direction, and the rocker arm shaft 2 on which the rocker arm lubrication hole 2b is located has an outer peripheral surface which is V-shaped in cross section in parallel with the shaft. -Shaped minute groove 2c is formed, and further, in the boss portion 1a into which the rocker arm shaft 2 of the rocker arm 1 is inserted, the oil hole 1b is constant at a position displaced from the rocker arm oiling hole 2b in the axial center (half diameter) direction. The oil hole 1b and the rocker arm oiling hole 2b are arranged so as not to communicate directly with each other by opening a gap, and the lubricating oil can flow through the minute groove 2c between the oil hole 1b and the rocker arm oiling hole 2b. , Since the rocker arm 1 is rotated, the rocker arm 1 flows intermittently, and flows when the oil holes 1b and the minute grooves 2c are aligned.

The micro-grooves 2c formed on the rocker arm shaft 2 are stamped to form V-grooves. The rocker arm shaft 2 has its outer periphery polished after quenching to ensure durability. However, since the minute grooves 2c require a great number of steps if they are formed in the polishing process, they are processed before quenching. Since the groove is formed by the stamping method, the tool life is extended, and the groove area does not change much even if the outer circumference grinding allowance changes slightly, and the target amount of lubricating oil discharge can be easily achieved. .

With such a configuration, the lubricating oil is sent to the oil passage 2a provided at the shaft center of the rocker arm shaft 2, and the gap (oil between the rocker arm shaft 2 and the boss portion 1a of the rocker arm 1 is provided from the rocker arm oiling hole 2b. Clearance) is entered and lubricated. On the other hand, the oil amount of the lubricating oil from the rocker arm oiling hole 2b to the minute groove 2c is throttled by the minute groove 2c, flows out onto the boss portion 1a through the oil hole 1b, and travels along the upper surface of the rocker arm 1 to reach the valve system 5 Side and adjust bolt 3 side to supply lubrication oil to valves, valve guides, push rods, etc. to prevent wear. At this time, since the rocker arm 1 is reciprocally rotated, the rocker arm 1 is intermittently supplied between the minute groove 2c and the oil hole 1b, which prevents excessive supply.

Further, as shown in FIGS. 7 and 8, the minute groove 2c is not provided on the rocker arm shaft 2, but is formed on the inner surface of the boss portion 1a of the rocker arm 1 in the circumferential direction so that the minute groove 1c is formed. Rocker arm oiling holes 2b 'and 2b' are bored between the groove 1c and the oil passage 2a. Further, the oil holes 1b 'and 1b' are reversed to the boss portion of the rocker arm 1 which is displaced from the rocker arm oiling hole 2b. It is also possible to form a V-shape so that the lubricating oil is discharged to the valve stem 5 side and the adjustment bolt 3 side, and to lubricate in the same manner as described above.

[0013]

[Effect of device]

 Since the present invention is configured as described above, it has the following effects. In other words, the amount of lubricating oil is regulated to the optimum amount by the minute groove, and it is possible to prevent wear of the valve, valve guide, valve seat, and wear of the contact part of the push rod and rocker arm. I was able to do it. The micro-grooves could be easily formed, and the cost increase could be minimized.

[Brief description of drawings]

FIG. 1 is a side view of a rocker arm having a lubricating structure of the present invention.

FIG. 2 is a plan view of the same.

3 is a cross-sectional view taken along the line AA in FIG.

FIG. 4 is an enlarged sectional view taken along the line BB in FIG.

5 is an enlarged cross-sectional view taken along the line CC in FIG.

FIG. 6 is an enlarged sectional view taken along the line DD in FIG.

FIG. 7 is a side view of a rocker arm having another lubricating structure.

8 is a cross-sectional view taken along line EE in FIG.

[Explanation of symbols]

 1 rocker arm 1b oil hole 1c, 2c micro groove 2 rocker arm shaft 2a oil passage 2b rocker arm oiling hole

Claims (1)

[Scope of utility model registration request] 1. In a valve train using a rocker arm shaft axis as a lubricating oil passage, a rocker arm lubrication hole communicating with a lubricating oil passage of a rocker arm shaft and an oil hole for discharging to the outside of the rocker arm are provided with a constant gap. A lubrication structure for a valve gear, characterized in that the rocker arm oiling hole and the oil hole are connected in advance by a minute groove provided on the rocker arm or rocker arm shaft.