JPS61294106A - Tappet valve device of 4-cycle engine - Google Patents

Abstract

PURPOSE:To enable opening and closing of two valves through a single cam, by a method wherein a cam shaft is located right above an intake valve, the suction valve is opened directly through rotation of a cam, and an exhaust valve is opened through a locker arm forced into contact with the cam. CONSTITUTION:A cam shaft 2, provided with a cam 1, is so disposed that the cam 1 is positioned right above an intake valve 3, and is rotated in linkage with a crank shaft. The intake valve 3 is energized in a closing direction through a spring 4, and a gap between the spring and the cam 1 is regulated by a shim 5. A locker arm 7, rockably mounted to a locker shaft6, is positioned facing the cam 1 in a manner that the base end of the locker arm is displaced by a suction and an exhaust timing by an angle, and the forward end is forced into contact with the upper end of an exhaust valve 9 through the medium of an adjust screw 8. The exhaust valve 9 is energized in a closing direction through a spring 10. This, when the cam shaft 2 is rotated in linkage with that of a crank shaft, enables opening and closing of both the intake valve 3 and the exhaust valve 9 along with rotation of the cam 1.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a valve train for a cycle engine.

[Technical background and problems of the invention]

In the engine cycle engine, the camshaft is linked to the crankshaft, and the camshaft is equipped with an intake cam and an exhaust cam, and each swings a rocker arm to push down the intake and exhaust valves to open and close them. This requires two types of cams, one for intake and one for exhaust, which takes time and effort to process, and the structure is complicated as there are many rocker arms. There are also camshaft cams that open and close the intake and exhaust valves directly without going through the rocker arm, but in this case, the cams are placed directly above each valve, so two camshafts This also results in a complicated structure, high manufacturing cost, and heavy weight.

[Purpose of the invention]

In view of the above, an object of the present invention is to provide a valve operating system for a double cycle engine that opens and closes both an intake valve and an exhaust valve using a single cam, and can be made simple in structure, inexpensive, and lightweight.

[Structure of the invention]

Embodiments of the present invention shown in the drawings will be described below.

FIG. 1 and the first time show one embodiment of the present invention. The camshaft λ provided with the cam/ is connected to the intake valve 3 with the cam/
Place it so that it is directly above it, and rotate it by interlocking it with the crankshaft using a chino etc. The intake valve 3 is urged to close by a springer, and the gap between it and the cam is adjusted by a shimta.

The rocker arm 7, which is rotatably attached to the rocker shaft t, has its base end opposed to the cam with an angle shifted by the intake/exhaust timing, and its tip is attached to the upper end of the exhaust valve via an adjustment screw g. guess. The exhaust valve 2 is biased closed by a spring 10.

When the camshaft rotates in conjunction with the crankshaft, the rotation of the cam pushes down the intake valve 3 against the spring to open and close it. Further, the rotation of the cam swings the rocker arm 7 and pushes down the exhaust valve against the spring 10 to open and close it.

3 and 7 show other embodiments of the present invention. As shown in FIG. 7, there are two intake holes, two exhaust holes, and two exhaust holes.
In this case, a cam is placed directly above each of the two intake valves 3, and the rocker arm 7 of the exhaust valve is aligned with one of the cams. In this case, although it looks like there are two cams, they have the same shape and can be machined with one grinding.

〔Effect of the invention〕

As explained above, in this invention, the cam of the camshaft is placed directly above the intake valve so that the rotation of the cam directly pushes the intake valve open, and the rocker arm that is swingably attached to the rocker shaft is attached to the cam. The exhaust valve is pushed open via the rocker arm, and one cam opens and closes the intake and exhaust valves, so the cam only needs to be of one shape, and the load is reduced. It can be made cheap and lightweight.

Further, since the rocker arm only needs to be placed on the exhaust valve side, the number can be halved, making it cheaper and lighter.

[Brief explanation of drawings]

1 and 2 show one embodiment of the present invention, FIG. 1 is a vertical side view, FIG. 2 is a plan view, and FIGS. 3 and 7 show other embodiments of the present invention, FIG. 3 is a plan view, and FIG. 1 is a layout diagram of intake and exhaust holes. C...Cam, K...Camshaft, 3...Intake valve,
6...Rocker shaft, 7...Rocker arm,
Wah...exhaust valve. Applicant's representative Kiyoshi Inomata Figure 3 Figure 2 Figure 4

Claims (1)

[Claims] The cam of the camshaft is placed directly above the intake valve, and the rotation of the cam directly pushes the intake valve open.
A rocker arm, which is swingably attached to a rocker shaft, is applied to the cam and the exhaust valve is pushed open via the rocker arm, so that the intake valve and the exhaust valve are opened and closed with one cam. A characteristic 4-stroke engine valve train.