JPH034728Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a rocker arm with a built-in lash adjuster that automatically adjusts the valve clearance to zero in a valve operating mechanism of an engine.

As this type of rocker arm, there is one published in Japanese Utility Model Application Publication No. 13505/1983 as shown in Fig. 1.
According to this prior art, the plunger b of the latch adjuster a is assembled to the rocker arm body c in a fully extended state, that is, in a forward position. As shown in Fig. 1, this rocker arm is placed in a predetermined position after the camshaft d and the intake and exhaust valves e are attached to the cylinder head, and its cam contact end f is connected to the cam g, and the plunger b is connected to the intake and exhaust valves. By inserting the rocker shaft i into the shaft insertion hole j while abutting the stem end h of the shaft e, the rocker shaft i is assembled to the cylinder head.

However, since the rocker arm is in contact with the stem end h when the plunger b is fully extended, the entire rocker arm is pushed upward as shown by the arrow, and the center of the shaft insertion hole j is aligned with the rocker shaft i shown by the imaginary line. As a result of being deviated upward from the axis during insertion, the locking shaft i is inserted into the shaft insertion hole j.
It becomes difficult to insert the Moreover, due to the presence of oil in the upper space of the plunger b of the latch adjuster a, it is difficult to quickly retreat the plunger b.
It is difficult to perform the insertion work quickly.

In addition, in the prior art, the plunger b
Although a locking ring k is disclosed for preventing the plunger b from falling off, it is clear from FIG. 1 that this does not lock the plunger b in the retracted position.

The purpose of the present invention is to solve the problems of the prior art described above, and a locking arm with a built-in locking adjuster is constructed by removably attaching a member for locking the plunger of the locking adjuster in the retreated position to the locking arm main body. It is characterized by the fact that

The present invention will be specifically explained below based on the embodiments shown in FIGS. 2 to 7.

The embodiment shown in FIG. 2 relates to a single overhead camshaft (SOHC) type valve mechanism. The rocker arm 1 is swingably supported by a rocker shaft 2 inserted into a shaft insertion hole 36 in the center thereof, and has a cam contact end 3 at one end thereof.
contacts the cam 5 of the camshaft 4, and the plunger 7 of the lash adjuster 6 built into the other end contacts the stem end 9 of the intake/exhaust valve 8.

A cylindrical adjuster accommodating chamber 11 with an open bottom is formed in the main body 10 of the rocker arm 1, and a bottomed cylindrical plunger 7 is slidably accommodated therein.

A guide cylinder 12 is slidably fitted into the upper part of the plunger 7, and its upper end is connected to the top surface 14 of the adjuster housing chamber 11 via a spacer plate 13.
It is arranged so that it comes into contact with the Further, a return spring 15 made of a compression spring is interposed between the guide tube 12 and the plunger 7 to urge the plunger 7 downward. Further, the guide cylinder 12 is provided with a valve hole 22 that communicates between the upper oil chamber 23 located above and the lower oil chamber 24 located below, and a check ball 16 that opens and closes the valve hole 22 and a check ball 16 that opens and closes the valve hole 22 and a check ball 16 that opens and closes the valve hole 22, A check valve mechanism 18 is provided with a spring 17 that supports the valve hole 22 and presses it against the valve hole 22. The check valve mechanism 18 is configured to open only when the pressure in the upper oil chamber 23 exceeds the pressure in the lower oil chamber 24 by a predetermined value or more.

Upper oil chamber 23 of the adjuster housing chamber 11
is the oil passage 1 provided in the Rotsuka arm body 10.
9, it communicates with the pressure oil passage 20 of the rock shaft 2.

The above configuration and the functions described below are well known. When the intake/exhaust valve 8 is closed, the plunger 7 and the guide cylinder 12 are urged against each other by the return spring 15, so that the valve clearance becomes zero. When the cam 5 pushes up the rocker arm 1 and swings it counterclockwise in FIG. 2, the oil pressure in the lower oil chamber 24 increases and the check valve mechanism 18 closes.
Since the plunger 7 is prevented from retreating, the intake and exhaust valves 8 are pushed down by the plunger 7 and opened. At this time, a part of the oil in the lower oil chamber 24 leaks into the upper oil chamber 23 through the gap between the plunger 7 and the guide tube 12, but when the intake and exhaust valve 8 is closed, the return spring 15
As the pressure in the lower oil chamber 24 is reduced by the action of , the oil in the upper oil chamber 23 enters the lower oil chamber 24 through the check valve mechanism 18, and the leaked oil is replenished.

The present invention is characterized in that a member 25 for locking the plunger 7 in the retreated position is detachably attached to the rocker arm body 10. In this embodiment, the locking pin 25a is attached to the adjuster housing chamber 11 of the rocker arm body 10. The locking pin 25a is removably inserted into a locking hole 26 provided near the lower end of the periphery of the locking pin 25a.
The tip of the plunger 7 is locked to the lower surface 21 of the plunger 7, thereby locking the plunger 7 in the retracted position.

A member 2 that locks the plunger 7 in the retracted position
5 is the insertion fitting 2 shown in FIGS. 3 and 4.
5b, U-shaped pin 25c shown in FIGS. 5 to 7
It is also possible to adopt

The insertion fitting 25b shown in FIGS. 3 and 4 has its upper protruding pieces 27, 27 attached to the upper surface 28 of one end of the rocker arm body 10, and its lower protruding pieces 29, 29 attached to the lower surface 30 of one end of the rocker arm body 10. The lock arm main body 10 is brought into contact with the
It is removably attached to the In addition, in this attached state, the plunger 7 is locked in its retracted position by the upwardly bent bent portions 31, 31 of the lower projecting pieces 29, 29. Note that 32 is a gripping protrusion for easily inserting and removing the insertion fitting 25b.

The U-shaped pin 25c shown in FIGS. 5 to 7 is
Locking protrusions 34, 34 engaged in locking holes 33, 33 provided on both sides of one end of the rocker arm main body 10
The locking protrusions 34, 34 and the locking hole 3
3 and 33, it is removably attached to the rocker arm main body 10. Further, a locking groove 35 is formed in the outer peripheral surface of the plunger 7 in the circumferential direction, and when the U-shaped pin 25c is attached to the rocker arm body 10, the locking protrusions 34, 34 are inserted into the locking groove 35. By engaging the tip, the plunger 7 is locked in the retracted position.

Next, a method of attaching the rocker arm of the present invention to the cylinder head will be explained based on the embodiment shown in FIG.

Locker arm body 10 and lash adjuster 6
With the plunger 7 set in the retracted position, the locking pin 25a is inserted into the locking hole 26 of the rocker arm body 10. Next, the rocker arm main body 10 is filled with oil to complete preparations before mounting the rocker arm 1.

First, the camshaft 4 and the intake and exhaust valves 8 are attached to the cylinder head at predetermined positions, and then the rocker arms 1, 1, . . . are arranged at predetermined positions. At this time, since the plunger 7 is in the retracted position, the center of the shaft insertion hole 36 of the rocker arm 1 can be easily aligned with the axis of the rocker shaft 2 when it is inserted. Therefore, the next work of inserting the rock shaft 2 can be done easily and quickly.
By this operation, the rocker arm 1 is attached to a predetermined position on the cylinder head.

Thereafter, when the locking pin 25a is removed, the plunger 7 moves forward and contacts the stem end 9 of the intake/exhaust valve 8, and at the same time, the one end 3 of the rocker arm 1 contacts the cam 5, completing the installation work.

The present invention can be configured in various ways other than those shown in the above embodiments. For example, the latch adjuster 6 may be constructed in a manner similar to that shown in the prior art shown in FIG. 1, or may be of a sealed type. Further, the position at which the plunger 7 is locked may be the most retracted position, but is not limited thereto, and may be any retracted position that allows the locking shaft 2 to be easily inserted.

Since the present invention has the above configuration, the following effects can be achieved.

The member that locks the plunger in the retreated position is removably attached to the locking arm body, so
The work of inserting a rocker shaft can be done easily and quickly, and the work of attaching a rocker arm with a built-in lash adjuster to a cylinder head can be done easily and quickly.

Before the locker arm is attached to the cylinder head, the locking member can prevent the latch adjuster from separating from the locker arm body, and there is no need for a locking ring as shown in the prior art. The number of points can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a partially longitudinal side view of the prior art published in Utility Model Application Publication No. 47-13505, Fig. 2 is a partially longitudinal side view of the embodiment of the present invention, and Fig. 3 is a partially longitudinal side view of the prior art disclosed in Japanese Utility Model Application Publication No. 47-13505. FIG. 4 is a side view of the main parts of the embodiment, FIG. 4 is a perspective view of the main parts, FIG. 5 is a side view of the main parts of yet another embodiment of the present invention, and FIG. Figure, 7th
The figure is a plan view of its main components. 1... Locker arm, 6... Latch adjuster, 7... Plunger, 10... Locker arm main body, 25... Member for locking the plunger in the retreat position.

Claims (1)

[Scope of utility model registration request] A locking arm with a built-in locking adjuster, characterized in that a member for locking the plunger of the locking adjuster in a retracted position is removably attached to the locking arm body.