JPS59208112A - Lash-adjustable valve rocker arm - Google Patents

Abstract

PURPOSE:To facilitate the machining of an air vent hole by extracting the air in oil through gaps between the side wall of a cylinder on which a plunger slides and a plate provided in the cylinder. CONSTITUTION:A plunger 11 with its lower end put in contact with the upper end of a stem is slidably provided on a cylinder port 9 formed on one end of a rocker arm 1. The inside of the plunger 11 is divided into the first oil chamber 13 and the second oil chamber 14 by a valve seat 12, and a check valve 19 is provided between them. An orifice plate 28 is provided between the valve seat 12 and the bottom surface of the cylinder port, and the air mixed in oil is discharged from an air vent hole 27 through gaps 29, 31 formed between the plate 28 and the cylinder wall. Since the oil flow is controlled by the gaps 29, 31, the air vent hole 27 is not required to be finely machined.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to the Ranonyu Adjustment Town M Hibarbrodka Arm.

As is well known in internal combustion engines, the valve A is used to absorb all of the thermal expansion of the engine ring or valve train due to the heat generated by the engine and smooth the valve operation.
・Butari Lance is set up in fl.

However, due to the presence of this valve clearance, is there a problem that noise (hitting sound) is generated in the valve train while the engine is running? pregnant.

Therefore, a valve train incorporating a lash adjustment device in the middle of the valve train has been proposed (for example, U.S. Pat. No. 2,925,074). Since it is incorporated into one cylinder block, it is easily affected by the heat generated by the engine. Therefore, there are drawbacks such as the viscosity of oil, which is the working medium of this lash adjustment device, changing and the operation becoming unstable. Therefore, a so-called lash-adjustable valve rocker arm has been proposed, which is incorporated into a valve rocker arm which is relatively less affected by heat.

By the way, one method of supplying hydraulic oil to this lash adjustment device is through forced oil supply from an oil pump. So, what is the outline of this type of forced lubrication system based on Figure 1, which shows the lash-adjustable valve lock arm? This will be explained below.

In the figure, / is the valve rocker arm body; ．． 2' (It is pivotally supported at the center of H.

This valve rocker arm body/one end Vcid, cam/
The cam μ attached to Gift 3 is in sliding contact, and its north end V
C is operatively connected to a nut 2α of a valve 2 that opens and closes each intake or exhaust passage j of the engine. 7 (Gubarubu Spring, Nokurubu Otsu? Constantly batting sword, Bushito.
? The rocker arm main body swings due to the rotational movement of the cam η, and as a result, ・Z /1. Button t moves up and down to perform all opening and closing operations.

One end (the connecting end for each valve in this embodiment) of the front Ar20 arm 4/ is provided with a cylinder hole formed to open downward. Inside the hole 9, a cylindrical plunger with a bottom is inserted and arranged in the same axial position Wl. /2 is the desired clearance within the plunger (preferably several μ to 1
Clearance of 0 few microns)? With the valve seat I, which is arranged to be slidably inserted, the valve seat/. 2Vc
The glazer//V'E section has a first oil chamber/3 and a second oil chamber/3 filled with and stored oil similar to engine lubricating oil.
There are two Vc units with q. 7.5 is valpusito 7
．． A through hole provided in the center of 2, this through hole/6 oil chamber 2/
L side [ij, check spring /7 in the spring seat /B and this check spring /7 biased in the direction of closing the through hole 15f'Lfc ball valve /
A check bar A/9 is provided.

The spring seat is placed in the second oil chamber/l.
/,<i via valve 1/7.2 and plunger//
The return springs T and S are spaced apart from each other and exert a force 1jiJU on the bottoms of the return springs T and S.

・1.2/ is located in the cylinder hole to prevent Jφ wear of the cylinder hole, and U is a stopper nog t' arranged on the outer periphery of the plunger//.

On the other hand, 2. ? One end, 23a is the rock shaft. It communicates with an oil pump (not shown) through an oil pump shaped like 1j5j inside 2, and the other end, 23b, is an oil introduction passage that communicates with the first oil chamber/3 inside Banotobunt/2.
This oil introduction passage, 7!3, is filled with oil similar to the lubricating oil that is supplied from the oil pump and lubricates the entire valley of the engine.
The first oil introduction hole 9a is formed in the soil part of the cylinder hole 7, and the notch 2a is formed in the upper edge of the cylindrical sheet 7.2. The oil is supplied into the silkworm 73.

, 26 C oil introduction] outlet, other end of 23, 2. ? An air venting member having an air venting hole 22 provided in b is used to remove air contained in the oil that is fed into the first oil guide 73 by following the oil introduction passage 23, and the first oil chamber thereof. ? Vent the outside air from the air vent hole 21 to prevent it from getting mixed in.
It is for T.

Next, the operation of the conventional blade/blocker arm having the above-mentioned configuration will be explained.

First, when the engine rotates, the camshaft J and the camshaft are rotated by the clubshaft (not shown), and the entire body of the force arm rotates in the direction of the warping indicator, so that the force arm rotates in the direction of the plunger. / is pushed down, thus opening the passage 6. As a result, the valve rocker arm body/
The spring force of the valve spring 7 that is applied to the valve spring 7 increases, and the oil in the second oil chamber/l is increased to 5 or 1. Pig 2nd (Exit room/4)
Some of the oil inside).

Ranoja // Gap 1ri between inner circumference and Barbunto /2
J r ] Kawatte, Palf Seaton, notch made in 2/
Escape from 2α to 4゛31 oil chamber/3. Therefore, it will sink by a small amount (X) relative to the plunger//Habalbro 7 arm body/.

As the plunger rotates further, the spring force of the valve spring 7 on the rocker arm gradually decreases, and the five passages close, finally reaching zero Vcif, so the plunger// returns to the return spring. m due to the spring force of 20
iJ notation α notation dimension pushed back. As a result, the second oil chamber 7'
The oil pressure in η decreases and the first oil chamber/X? l/i oil or check spring/Hole bar A/B against the spring force of 7.
, 1', and suction the first oil into the second oil chamber llt through all the communicating holes 7.5'. In this way, the plunger // will return to its original position as a whole, and the valve train's valve clearance will return to its original position. If this happens, the oil pressure of the first oil will drop slightly, but on this rare occasion, the hydraulic oil from the oil pump will be introduced till lf6.?3. Oil is supplied into the first oil chamber 73 through the oil introduction hole α and the notch 7204.
This hydraulic oil is used in the second oil chamber/η for adjusting the temperature.
/C supply will be 0.

p, changes in engine heat generation, etc. VC, 11 Niji,...Lube:
・When the rain valve clearance changes, the plunger // is moved by 4 g in advance by the spring force of the spring 20 so that its clearance is completely zero, and then the plunger ]l] Similarly,
During operation f3'lJ 9 pi α dimension expansion and contraction (Suri@I) (
11-Turn around and make the valve mechanism operate smoothly with zero pulp clearance.

By the way, in the conventional 7<)+-pronouncer arm having such a configuration, the oil is injected into the first oil introduction passage 73 of the oil introduction passage 23 from the oil Honda. Purple refueling - When filling, the air contained in the hydraulic oil gets mixed into the first oil chamber/3, and the air-containing hydraulic oil is sucked into the second oil chamber/η. , the so-called valve seat characteristic?In order to avoid instability, a full air vent @ member 2S is provided at the other end of the oil introduction passage, 2.?, 23b side, and the air vent formed by nVC is Measures have been taken to exhaust all the air in the hydraulic oil to the outside air from the holes 2 and 2 to obtain stable characteristics of the PJT. Since the hydraulic oil supply port to the ? and the air discharge port from the first oil chamber/3 are the same, that is, the hydraulic oil sent from the oil introduction passage 23 is connected to the oil introduction hole 9α and the notch/3. The air flowing into the first oil chamber 73 through the notch/2OL and the oil introduction hole 9α (11-) flows into the first oil chamber 73 through the air vent member 2j. Since the air flowed outside from 2t, there was a problem in that it was difficult to remove the air that had accumulated in the upper part of oil chamber No. 1/3.

As shown in Figure 2, such a problem occurs on 8F! 1. Air vent hole 27 is fully opened on the top surface of oil chamber/3, and the hydraulic oil supply port and air discharge port are completely separated.
When hydraulic oil flows into the oil chamber 73, the oil pressure causes the @1
The air accumulated in the upper part of the oil chamber/3 FE3 can be eliminated by directing all the air accumulated in the upper part of the FE3 to the outside from the air vent hole 27, or the hydraulic oil containing air from the oil introduction passage 23. Then, a vortex is generated in the hydraulic oil accumulated in the first oil chamber 73 in order to flow into the first oil chamber 73 at high speed and cause all the air accumulated in the first oil chamber 73 to flow out. A new dissatisfaction has arisen in that the air that has accumulated in the upper part of the first oil chamber/3 is completely entrained, causing a bubbling sound. Such displeasure @
How much air flows out from the air vent hole, the diameter r restriction of 27, and the 1st oil chamber/3? This problem can be solved by suppressing the flow of hydraulic oil in the first oil chamber/3 yen, but conventionally, as mentioned above, the hydraulic oil flow is prevented from occurring in the first oil chamber/3 yen. The air accumulated in the upper part of the first oil chamber/3 is directly discharged from the air vent hole 27 which opens on the upper surface of the first oil chamber/3 together with some oil. The drawback was that it was extremely difficult to prevent any flow from occurring.

This is because the amount of air flowing out from the first oil pump/3 is determined mostly by the diameter of the air vent hole 27, so in order to suppress the amount of air flowing out and prevent a fast flow from occurring. The diameter of the air vent hole 27 is made as small as possible (for example, 0
．． This is because it is extremely difficult to form all the air vent holes 27 with such a small diameter in terms of processing.

Is the present invention a drawback of the above-mentioned conventional technology? The purpose is to provide a valve rocker arm that can completely discharge the air in the first oil chamber without creating a fast flow fL in the first oil chamber, that is, without creating any swirls or bubbles in the hydraulic oil. There is. A plate for forming an orifice is interposed between the upper surface of the first oil chamber where the air vent hole opens and the upper end of the valve seat, and the outer peripheral surface of the plate and the first oil chamber are An orifice is formed between the inner chamber (1) and the air inside the first oil chamber, and the orifice and the air vent hole are valved to allow the air to flow out to the outside.

Hereinafter, an embodiment of the present invention will be described with reference to FIG. 3 and the following drawings. Note that the same parts as in the configuration of the conventional example are given the same reference numerals, and redundant explanation thereof will be omitted.

・Figure 83 is a partially cutaway front view showing one embodiment of the lash iA adjustable naval blocker arm according to the present invention.

In this Figure 3, 1.2 is the orifice plate, 2
De is the orifice plate, the outer circumferential surface of 2 and the 1st oil chamber/3
It is an orifice formed between the inward facing surface of the

The orifice plate 2g has a slightly smaller inner diameter than the first oil plate/3 and is formed into a perfect circle with a desired wall thickness, and the upper surface of the orifice plate has a circular shape shown in Fig. 4.5. 4
Four arcuate walls 30 are provided protrudingly at angular intervals of 5 degrees. And is this orifice inlet L/-t, the 2nd part, the center in the axial direction? When set at the axial center of the first oil chamber/3, the arm surface of the first oil N7.3 and the valve seat 7.2
It is installed between the upper end of the

In addition, the orifice scoter is formed in a so-called annular shape on the outer periphery of the orifice plate 2g by setting the orifice vent xr2 at the axial center of the first oil chamber/3 as described above. several tens of c/mi
It is now possible to obtain as much outflow as possible. a'M
``-r rL is set at the axial center of the first oil stroke/J, and two are the first oil strokes/, ?
An orifice 29 is formed with an outer diameter that can obtain the above-mentioned outflow amount between the inward facing surface and the inward surface of the orifice 29.

Since the valve rocker arm of the preferred embodiment has the above-mentioned configuration, when oil containing air flows into the first oil chamber/3 from the oil trap passage 23, the oil causes the sail oil to The air (strictly speaking, the air mixed with oil) accumulated in the chambers 1 and 2 flows through the orifice, orifice plate, and 2.
The gap between g and the top of the first oil chamber/3? /, air vent hole,
27 all pass through and flow out to the outside. The amount of outflow at this time (about several tens of cc/m i 24, and this &8
With a flow rate of 1.5 degrees, a fast flow is not possible in the first oil chamber 73, and therefore the generation of vortices and bubbles in the first oil chamber 73 is prevented, and the valve lift characteristics caused by these vortices and bubbles are This is to prevent destabilization.

Although the embodiment shown in Figure rfI:JVc shows the case where the orifice dog plate is formed in a circular shape, it may be in an elliptical or other shape.

As described above, each of the intake or exhaust air pumps of the present invention are pivotably supported on the rocker shaft, are oscillated by the rotation of a cam sliding on one end, and are operatively connected to the other end. A valve rocker arm body that allows the valve to fully open and close, and an opening formed at one end of the valve rocker arm body to open downward, and inserted into the f'Lfc cylinder hole so as to be slidable in its axial direction. A cylindrical plunger with a bottom is arranged, and inside this plunger, there is a partition between the entire A41 r mountain and the 2nd rII1.
From the 1 m chamber of the iiJ sword installed in the through hole of this valve seat, the blade was inserted into the valve seat and fixed itself.
υBe+Archive 2 Only the same oil flow in the oil chamber, total capacity 1-ru 1 chamber J-bu, and the bow I in the front 2nd/yu chamber.
JM's plunger's brim; section and front 11 pival bunt? The return springs are spaced apart from each other and are biased in the direction of
``Rocker arm body Q'' for lash control, fully equipped with an oil introduction passage that communicates with the first oil chamber at the other end. This is JJ on the Ichibanawa side! An air vent hole opening in the upper part of the first oil chamber is provided, and a plate r for a burnt orifice shape is interposed between the upper surface of the first oil chamber and the upper surface of the valve note. Is there an orifice in the darkness between the outer circumferential surface and the 18 circumferential surface of the force 1 oil chamber? Form and first
Since the oil and air, etc. are allowed to flow out of the external VC through all of the orifices and air vent holes, there is an effect as described below.

(1) When letting the air in the first oil chamber flow out directly from the air vent hole provided in the blocker arm body, adjust the air flow according to the diameter of the air vent hole, It is necessary to prevent a fast flow from occurring inside the chamber, but in reality, it is difficult to form the air vent holes in the first oil chamber IJc to a small diameter that prevents a fast flow from occurring because the machining is difficult. In contrast, in the present invention, the outflow amount is adjusted using the orifice plate. This eliminates the need for the conventional cumbersome and difficult drilling process of creating air vent holes with a small diameter.

(2) Prepare several types of orifice plates with different diameters and shapes in advance, and change the number of the orifice plates. You can prepare sea bream.

[Brief explanation of the drawing]

・Fig. 1 shows the conventional bar A/blocker arm for a part of I wave breaking pressure I, and Fig. 2 shows the hydraulic oil supply port to the 1 oil chamber and from the :P, ] /I] chamber. Separated air outlet. </l+70 Partially broken front view of 70 Tsuka arm, 3rd drawing Partially broken 1 place + E IN drawing showing one embodiment of the tsuka arm according to the present invention, ・North 4th figure is the same as in Fig. 3 Plan view of the orifice plate, Fig. 5 (σ is the same side view. /... Valve rocker arm" body, λ... mouth shaft, η... cam, 2... intake - fc is Exhaust (A・B, Ri...Cylinder hole, //...Plunger, /2...Valve seat, /8...1st oil chamber, /
l...2nd /[1] chamber, /6...through hole, /9...
Check valve 1.20...Return spring 1.2
3...Oil introduction passage, 23α...=Q1.2.3b...
・Other end, 27...Air vent hole 1.2g...No. 11
Fiss plate, 2... orifice.

Claims (1)

[Claims] (1) Opening/closing operation of each intake or exhaust valve which is pivotably supported on a rocker shaft and is oscillated by the rotation of a cam sliding on one end and operatively connected to the other end. A valve rocker arm body, and a bottomed cylinder that is slidably inserted in the axial direction into a cylinder hole that is opened downward at one end of the Conobag blocker arm body. The plunger has a first oil chamber and a second oil chamber inside the plunger.
I (lube seat) fitted and arranged so as to be separated from the oil chamber, and the first lubricant provided in the through hole of this z
A check valve for only allowing oil to flow from the oil chamber to the second oil chamber, and a bottom of the plunger and the valve seat in the second oil chamber? A friend return spring arranged so as to be elastically biased in a direction separating from each other,
An oil introduction passage whose one end communicates with the oil pump and the other end communicates with the first oil chamber? In the lash-adjustable valve rocker arm, the bar A/blocker arm main body 1c has an air vent hole opening at one end side to the upper surface of the first oil chamber, and the upper surface of the first oil chamber and the valve seat. A plate for forming an orifice is interposed between the upper end surface and the orifice metal is formed between the outer circumferential surface of the plate and the same circular surface of the first oil chamber. Lash adjustment QT tie half rocker arm that allows external VC to flow out through orifices and air vents.