JPS58126408A - Tappet mechanism of internal combustion engine - Google Patents

Abstract

PURPOSE:To eliminate the necessity for taking accout of the dimension tolerance on manufacture and improve the working efficiency by installing an adjust screw onto the connection part between a locker arm and the push rod of a hydraulic valve lifter. CONSTITUTION:An adjust screw 19 is installed onto the connection part between a push rod 4 and a locker arm 6 by means of a lock nut 20. When a tappet- valve system mechanism is installed, the installation length of the adjust screw 19 relative to the locker arm 6 is properly adjusted by revolving the lock nut 20, and thus each dimension tolerance on the manufacture of a cylinder block, cylinder head, head gasket, and each tappet-valve system component can be absorbed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a valve operating mechanism for an internal combustion engine N, and particularly to a mechanism for adjusting the clearance between pulp, a hydraulic valve lifter, and a cam in the valve operating mechanism.

In general, in internal combustion engines, it is necessary to provide valve clearance mainly to account for the difference between the thermal expansion of the cylinder head and the expansion of the valve mechanism.If this clearance is incorrect, noise will occur while the engine is running. There was a loss of horsepower due to the raw gas blowing through. As previously known, hydraulic valve lifters prevent the generation of noise by keeping the valve clearance at zero during the operation of the valve train, and also stabilize by absorbing the clearance caused by wear of various parts over time. It functions to operate the valve train. As shown in Figure 1, this hydraulic valve lifter is used by being attached to the valve train of an internal combustion engine.
In the figure, numeral 1 indicates a hydraulic valve lifter. This hydraulic valve lifter 1 is slidably loosely fitted into a through hole 3 formed in a cylinder block 2, and its upper end surface is operatively connected to the lower end surface 4a of the bushing rod 4, and its lower end surface is connected to the lower end surface 4a of the bushing rod 4. is in contact with. The cam 5 rotates by the crankshaft and moves up and down.

The vertical movement of the bushing rod 4 is transmitted to the rocker arm 6 via the upper end surface 4b of the bushing rod 4, and as a result, the valve 7 is opened and closed.

Furthermore, the configuration of the hydraulic pulp printer 1 is as shown in FIG.
It mainly consists of a plunger 11 that is fitted inside the die 10 and slides up and down, and a check valve 13 is attached to the lower end of the plunger 10 and the bottom of the plunger 11 and the bottom of the potty IO. A spring 14 is installed between the cylinder and cylinder 11 to urge the cylinder/jar 11 upward. Furthermore, a reservoir 15 in the glazer 11 and a pressure chamber 16 at the bottom of the body 10 are filled with oil. And if there is clearance in the valve train,
Silanja 11 to make this clearance zero?
The plunger 11 is pushed upward by the biasing force of the spring 14 relative to the D 10. Conversely, if the valve train becomes longer, the distance that the plunger 11 is pushed up is shortened by that amount, thereby smoothing the valve train. This is what makes it work.

The hydraulic pulp lifter shown in FIG. 2 is of a type called a sealed type, in which a retractable bag 12 is attached to the upper end of a syringe 11, and the oil in the pressure chamber 16 is released by the vertical movement of the plunger 11. The bag 12 moves in and out of the reservoir 15, and the expandable bag 12 expands and contracts accordingly, that is, it has a kind of breathing effect.

By the way, it is unavoidable that cylinder blocks, cylinder heads, head gaskets, and various valve train parts have dimensional tolerances due to manufacturing, and conventional hydraulic valve lifters do not have a mechanism to absorb such dimensional tolerances. In addition to the clearance adjustment between the cam handle and the pulp that is necessary to keep the valve train in the same state, which is the original purpose of the hydraulic pulp lifter, [normally above (0.5 to 1.0 hai)], the above product is Absorption of dimensional tolerance (usually 3 to 47111π
) must be set as the stroke of the hydraulic valve lifter.In particular, as mentioned above, in a sealed hydraulic pulp lifter, the plunger 11 moves into the oil reservoir 15 as the plunger 11 moves relative to the die 10. Because the expandable bag 12 performs a breathing action to absorb the inflow and outflow of the engine, the hydraulic valve lifter has to become very large, which makes the part heavy, which limits the engine speed and makes it difficult to increase the speed. There was a problem with being blocked.

The present invention has been made to solve the problems of valve train mechanisms equipped with such hydraulic valve lifters, and has a simple mechanism that absorbs the dimensional tolerances of various parts when assembling the engine. The object of the present invention is to obtain a valve train equipped with a hydraulic valve lifter that can be miniaturized and quantified so that the stroke of the hydraulic valve lifter can be suppressed to only the originally required adjustment amount.

The present invention is a bushing for a hydraulic valve lifter.

This objective was achieved by installing an adjustment screw at the connection between the rod and the rocker arm connected to the engine pulp.

Embodiments of the present invention will be described according to the drawings.

FIG. 3 shows a conventional valve train equipped with a hydraulic pulp link, shown to clarify the comparison with the present invention, in which the bushing rod 4 of the hydraulic valve lifter 1 is directly connected to the rocker arm 6, and the cam 5 rotates. Hydraulic valve lifter by
The vertical movement of the engine valve 7 is transmitted to the engine valve 7 to open and close it. Therefore, in such a valve mechanism, in order to absorb dimensional tolerances of the cylinder head, cylinder block, head gasket (not shown), push rod 4, etc. during assembly, it is necessary to adjust the clearance of the hydraulic valve lifter 1. The stroke lengths a' and b' are larger than the values originally required for one set of hydraulic pulp lifters, and therefore, if the total length t' of the hydraulic valve lifter is large, the weight becomes heavy.

Incidentally, in Fig. 3, a' is the stroke required between the snap ring 17 and the nosh rod seam 18, and the cylinder part and valve train parts are required to take the necessary effort to cope with cam wear. In addition, b' is the stroke required between the lower end 11m of the cylinder/jar 11 and the shoulder 10a at the bottom of the engine valve 7 and the valve seat. Each figure shows the originally necessary adjustment for wear plus the absorption of dimensional tolerances of the cylinder and valve train parts.

FIG. 4 shows an embodiment of the present invention, in which the connection between the dash rod 4 and the rocker arm 6 is different from the conventional valve train structure shown in FIG. An adjustment screw 19 is attached to the part using a lock nut 20.

With this configuration, when assembling the valve train mechanism, the installation length of the assist screw 19 to the rocker arm 6 can be adjusted as appropriate by rotating the lock nut 20. , the cylinder block, cylinder head, head gunket, and other valve train parts can be accommodated for the manufacturing dimensions, so the adjustment stroke required to assemble the hydraulic valve lifter to the valve train is the same as above. Snap ring 1 that corresponds to the wear of the cam, which is the originally required adjustment amount excluding the absorption of dimensional tolerances of each part.
The stroke a between the valve 7 and the bushing rod seat 18, and the plunger lower end 1111 corresponding to wear between the valve 7 and the valve seat (!: m between the M section 10a at the bottom of the body)
Since it is clear that a〈a', b (b'), compared to the conventional drilled valve mechanism, a stroke of a+b<a'10b is required. , the total length t of the hydraulic valve lifter 1 is also shorter than the total length t' of the conventional example.
<t', the weight of the hydraulic pulp lifter can also be reduced. Moreover, even if the weight of the adjustment screw 19 and the lock nut 20 is added, the weight can be made lighter than that of the conventional hydraulic valve lifter, so that the engine speed is not limited as in the conventional case.

Note that this example shows a type in which a cam contacts the lower end of the hydraulic valve lifter and moves it up and down.
The present invention is not limited to this type, but can also be applied to a so-called over-type valve mechanism in which a cam is provided above the valve and the hydraulic valve lifter, or to a Rad camshaft type valve mechanism. Moreover, it is particularly effective when applied to the sealed hydraulic valve lifter shown in FIG.

As explained above, the present invention operates the stroke of a hydraulic valve lifter by simply adding an adjustment screw to the connection between the bushing rod of the hydraulic valve lifter and the rocker arm connected to the valve. The adjustment can be kept to the amount originally required to keep the valve system in the same state at all times, and there is no need to consider the manufacturing tolerances of each part. It has a remarkable effect compared to the conventional technology, in that it enables quantification and allows the engine to run at higher speeds.

[Brief explanation of drawings]

Figure 1 is a sectional view of the main parts of an internal combustion engine equipped with a valve train mechanism, Figure 2 is a sectional view of a sealed hydraulic pulp lifter, Figure 3 is a configuration diagram of a conventional valve train mechanism, and Figure 4 is a booklet. FIG. 1 is a configuration diagram of an embodiment of a valve train mechanism of the invention. 1... Hydraulic valve lifter, 4... Bush rod,
5...Cam, 6...Rocker arm, 7...Engine valve, 10...Gidi, 10a...d? D-bottom shoulder, 11...F5 jar, 11 &... lower end of grandjar, 12... elastic bag, 17... snap ring, 18... bush rod seat, 19... adjust screw 120...Rocknut, 21.
・Sealed hydraulic pulp lifter. Fig. 1 6 Fig. 2 17 Ha0 8 1 2 5--13 Fig. 4 19

Claims (1)

[Claims] A valve mechanism for an internal combustion engine in which an adjustment screw is attached to the connection between the bushing rod of the hydraulic valve lifter and the rocker arm connected to the engine pulp.