JPS6181504A - Sealed type rush adjuster - Google Patents

Abstract

PURPOSE:To dispense with a supply of hydraulic fluid from the outside, by installing an elastic seal in space between a body and a pivot, while putting the hydraulic fluid flowing out of a clearance between the body and a plunger back to a reservoir through a return hole installed in the pivot. CONSTITUTION:A bottomed cylindrical body 9 is inserted into a cylinder head, while a plunger 10 having a pivot 11 is inserted into this body from the opening side. An elastic seal 17 is installed in space between the body 9 and the pivot 11, thus a sealed type rush adjuster 5 is constituted. A return hole 19 is installed in the pivot 11 or the plunger 10, through which it is so constituted that hydraulic fluid flowing out of a pressure chamber 13 through a clearance between the body 19 and the plunger 10 is put back to a reservoir 12. A supply of the hydraulic fluid to the reservoir from the outside is no longer required without making a cylinder structure into complication and, what is more, air dust and foreign substances are in no case entered at all as being intercepted from the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field 1) The present invention relates to a sealed lash adjuster for supporting the end of a rocker arm, etc. in an OHC type valve mechanism of an internal combustion engine. This invention relates to a system for recovering oil leaking from a pressure chamber through a gap between a body and a plunger into a reservoir chamber during valve-to-valve operation.

[Background of the invention 1] For example, if there is a J3 next to this type of valve,
As shown in Publication No. 6014, the rocker arm is supported by a lash adjuster at the end opposite to the valve head, and the valve clearance is configured to absorb changes in the offing due to temperature on the valve side, even in snowy conditions. An end-pivot type has been proposed. In this configuration, when the plunger of the lash adjuster is pressed downward during the valve opening operation due to the lift of the cam, an opposing hydraulic pressure is generated in the pressure seedling filled with incompressible oil to support one end of the rocker arm. At this time, part of the oil in the pressure chamber leaks through the gap between the body and the plunger due to the high oil pressure. Then, when the valve is closed by the base narcle of the cam and the plunger is in an unloaded state, the volume of the pressure mass is 1' of the plunge spring.
As the oil temperature increases, the oil is supplied to the reservoir chamber from the oil passage via the check ball, and acts to replenish the oil being supplied. In other words, the lash wheel 1r pump breathes oil every time the cam rotates once.

Therefore, the lash adjuster that operates in this manner has the following drawbacks. First, check the oil passage and reservoir!
The oil supplied to the engine usually contains a certain proportion of air (a), so these air bubbles enter the pressure and reduce the incompressibility, which causes the rocker arm's fulcrum position to become misaligned when the cam is lifted. The normal valve lift curve cannot be maintained. When installed horizontally in a horizontally opposed engine, the oil in the reservoir chamber easily flows out through the oil passage after the engine is stopped, and the air in the reservoir chamber is sucked into the pressure chamber when the engine is restarted. This may result in insufficient valve opening or excessive noise. Furthermore, it is necessary to provide an oil passage in the cylinder head, which complicates the structure. Furthermore, dirt and foreign matter in the oil supplied to the reservoir chamber often impairs the performance of the lash adjuster.

Incidentally, conventionally, as a sealed lash adjuster, an elastic seal is installed between the body and the plunger as shown in Machima 55-160106, and
As shown in Japanese Patent No. 1581N, there are some seals in the gap between the body and the plunger, but these merely prevent oil from leaking to the outside from the gap between the body and the plunger.

fObject of the Inventionj In view of the above-mentioned problems (51*Technique 14j), the present invention collects oil leaking from the gap between the body and the plunger into the reservoir chamber and drains the oil from the oil passage opening. To provide a sealed lash adjuster that self-manages oil without requiring oil replenishment.

[Configuration of the Invention] For this purpose, the configuration of the present invention is to provide an extensible seal between the open side of the body and the plunger or pivot, the shape or elasticity of which can absorb the maximum amount of movement thereof; In addition, an oil return hole is provided in the plunger or the pot, and the oil to be drawn out from the gap between the small plate and the plunger can be sealed with a seal.1. ? L. The purpose of freezing is to return the oil from the oil return tank to the reservoir chamber.

[Example] Hereinafter, practical examples of the present invention will be specifically described based on the drawings.

In FIG. 1, a first embodiment will be described together with a valve lock to which the present invention is applied. In the figure, numeral 1 is a cylinder head, 2 is a valve, and this valve 2 is connected to a cam 4 via a rocker arm 3. A lash adjuster 5 is provided in an end-pivot manner at the opposite end of the rocker arm 3 to the valve 2. The valve 2 is closed when the valve spring 7 is biased between the retainer 6 on the stem end side and the cylinder head 1 and engages with the valve seat 8 as shown in the figure, and moves downward against the valve spring 7. By doing this, you learn to listen.

In the lash adjuster 5, a bottomed cylindrical body 9 is inserted into the cylinder head 1 approximately perpendicularly, and a plunger 10 is movably inserted into the body 9 with a predetermined clearance. A pivot 11 projecting upward from -10 makes spherical contact with the rocker arm 3. Further, inside the plunger 10, oil is stored or connected to a reservoir 12, and a pressure chamber 13 is formed below the plunger t-70 inside the body 9. The spring 14 is biased, and the check ball 1G is pushed into the communication hole 15 between the reservoir chamber 12 and the pressure chamber 13 of the plunger 10.

Furthermore, a hat-shaped elastic seal 17 is attached between the opening side of the body 9 and the pivot 11. This seal 17 is partially protruded and is formed to be expandable and contractible to absorb the maximum movement of the plunger 10. The gap T between the body 9 and the plunger 10, J3 and the elastic seal 17
Plunge l- to communicate the inside of the reservoir with the reservoir ￥12.
An oil return hole 113.19 is bored in the upper side J3 of 10.

Next, the operation of the valve train (branch) constructed in this way will be explained. First, when the lift of the cam 4 pushes the bit 11a and the plunger 10 of the lash adjuster 5 downward via the rocker arm 3, the pressure chamber 13
A high hydraulic pressure is generated to counter the pressure, and the stiffness becomes f, which causes the rocker arm 3 to swing around the pivot 11, causing the valve 2 to move downward against the valve spring 7, causing the valve 2 to open. An action is taken. At this time, the gap γ between the pressure chamber 13 and the body 9 and the plunger 100 is
The oil leaking through the oil return hole 18 returns to the reservoir chamber 12 through the oil return hole 18 and, after being captured by the IT elastic seal 17, also returns to the reservoir chamber 12 through the oil return hole 19.

One, is the base knurcle of cam 4 causing valve 2 to become valve seat 8? When the valve is closed after 3 m and the pivot 11 etc. are in the unloaded state, the volume of the pressure chamber 13 is increased by the plunger spring 14 and acts to close the valve clearance. And at this time, Masu r Tsuku ball 1G
is opened, and the oil in the reservoir chamber 12 is replenished into the pressure chamber 13 through the communication hole 15.
The oil recovered through 8.19 will also be used again.

d5, the present invention is not limited to the above embodiments, and as shown in FIG. 2 (2), a metal bellows-shaped seal +7
- may be used, and the plunger 10 can be used as shown in the same figure (b).
Alternatively, a separate member, the pivot 11', may be press-fitted into the plunger 10 and the elastic seal 17. Alternatively, as shown in FIG. 3, the upper part of the plunger 1 to 10 may be made to protrude to have approximately the same thickness as the body 0, and a bellows-shaped seal 17'' may be placed between the two.

Furthermore, cam and push in OHV type valve Rfil.

The oil tabs 1-1 installed between the cylinders have the same configuration as the lash 7 gears that are the object of the present invention,
Therefore, the present invention can also be applied to oil tappets.

[Effect of the invention 1] As is clear from the above actual M example, according to the present invention, in the lash adjuster that supports the end of the rocker arm, etc., the reservoir chamber 12 is connected to the outside without complicating the column 1 of the cylinder head. Since there is no need to supply oil from
It is shut off from the outside and the oil is self-managed, effectively forming a rich sealing system, and there are no air bubbles, dust, or foreign substances, so the lash adjuster's performance is not impaired and the oil is leveled. Like an opposed engine: advantageous when pushed sideways. Since the oil pressure of the reservoir chamber 12 can be arbitrarily set by the elasticity of the elastic seal 17, etc., it is possible to raise the pump-up current level, etc.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of a lash adjuster according to the present invention, and FIGS. 2(a), (b), and 3 are cross-sectional views of essential parts without showing other embodiments of the present invention. be. 5... Lash adjuster, 9... Body, 10 River plunge V, 11... Pivot, 12... Reservoir chamber, 13... Pressure chamber, 17.17-, +7"...
・Seal, 48.10...Oil return hole, γ...Gap. Patent applicant: Fuji Heavy Industries, Ltd.

Claims (1)

[Claims] An extensible seal having a predetermined elasticity is provided between the opening side of the body and the plunger and the integral pivot of the plunger inserted therein, and an oil return hole is bored in the plunger or the pivot. A sealed lash adjuster that returns oil leaking from the gap between the body and plunger to the reservoir chamber.