JPS6021443Y2 - Locker arm mechanism for internal combustion engines - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a rocker arm mechanism that constitutes a valve train in an internal combustion engine, and in particular to a rocker arm mechanism suitable for use in a gasoline engine or a diesel engine. A bushing rod is engaged with one end of a rotatable rocker arm that is integrally attached to the shaft, and the push-up action of this bushing rod causes the other end of the rocker arm to pivot downward, thereby lifting the valve a predetermined amount. It is designed to release by pressing down on the button.

Generally, the amount of displacement (lift amount) required to open and close a valve is
Its size affects the quality of combustion efficiency.

However, in the conventional rocker arm mechanism as described above, the positions of the bushing rod, rocker shaft, and valve shaft are predetermined, so the rocker ratio (the distance from the fulcrum of the rocker arm to one end and the distance from the same fulcrum to the other end) The lift amount of the valve is also constant, and as a result, the combustion efficiency determined by this lift amount (not necessarily the highest combustion efficiency).

) is the problem.

The present invention attempts to solve these problems, and aims to provide a rocker arm mechanism for an internal combustion engine that allows the lift amount of a valve to be adjusted as appropriate.

Therefore, the rocker arm mechanism of the present invention includes a 10th lever arm that has one end engaged with a bushing rod for opening and closing a valve in an internal combustion engine, and a 20th lever arm that comes into contact with the other end and receives the acting force of the bushing rod. and a valve that opens when pressed by the 20th lever arm, so that the 20th lever arm can change and adjust the distance from its fulcrum to the point of force and the distance from the fulcrum to the point of action, respectively. It is characterized by being provided in the cylinder head so that its position can be adjusted.

Below, a diesel engine rocker arm mechanism as an embodiment of the present invention will be explained with reference to the drawings. Fig. 1 is a schematic diagram for explaining its principle, and Fig. 2 is a perspective view schematically showing its arrangement state. , FIG. 3 is a front view showing how it is arranged in an actual machine.

As shown in FIG. 2, a tenth lever arm 1 is integrally attached to a rocker shaft 2.
It can be rotated around the center.

A pin 1a extending downward is provided at one end of the tenth hook arm 1, and a bushing rod 3 is engaged with this pin 1a.

Note that the bushing rod 3 is moved up and down by a cam (not shown) via a tappet.

Furthermore, the other end of the 10th lever arm 1 is connected to the 20th lever arm 1.
It abuts the arm 4 from above, so that the 20th latch arm 4 receives the acting force of the bushing rod 3 via the 10th latch arm 1.

Further, the tip of the 20th lever arm 4 is in contact with the upper end of the sub-valve 5, and when the upper end of the sub-valve 5 is pressed under the force of the second bushing rod 3, the sub-valve 5 is moved by the spring 6. It is designed to open against forces.

Note that the sub valve 5 is closed by the action of the spring 6 when it is not pressed by the 20th lever arm 4.

By the way, the 20th rocker arm 4 is attached to the rocker arm support 7 so that it can be rotated in the vertical plane and finely adjusted up and down. It is attached to the cylinder head 10 so that its position can be adjusted by tightening a nut 9 through a valve 8 inserted into the elongated hole 7a.
The arm 4 can change and adjust the distance 13 from the fulcrum 02 to the point of force and the distance t'4 from the fulcrum 02 to the point of action B2.

Furthermore, as shown in FIG. 1, the lift of the bushing rod 3 is measured, and the fulcrum O□ of the tenth hook arm 1 is determined.

Distance from force point A□/iyIf the distance from the fulcrum 0□ of the tenth lever arm 1 to the point of application a is 12, the lift amount H of the sub-valve 5 is expressed by the following equation.

H=h, /2-1・2, 2゜In the above formula, h, l□, 12 are constant values, but 13
? Since li is variable as described above, the lift amount H of the auxiliary valve 5 can be adjusted accordingly to obtain the best combustion efficiency.

Furthermore, in the actual machine, as shown in FIG. 3, the bushing rod 3 is engaged with one end of the main rocker arm 11, and the tenth lock arm 1 is fixedly attached to the rocker shaft 12 that is common to the main rocker arm 11. As a result, when the bushing rod 3 rises, the main rocker arm 1
1 rotates counterclockwise, the tenth hook arm 1 also rotates counterclockwise, and the acting force of the bushing rod 3 is transmitted to the twenty hook arm 4.

In this case, the main rocker arm 11 is connected to the main valve 1 at the other end.
Press 3 to release it.

In addition, in FIG. 3, the same reference numerals as in FIGS. 1 and 2 indicate substantially the same parts.

In the above-described embodiment, the rocker arm mechanism of the present invention is applied to the auxiliary valve 5 of a diesel engine, but it may also be applied to the main valve 13 of a diesel engine. It goes without saying that this may be applied to both valves.

As described in detail above, according to the rocker arm mechanism of the present invention, since the 20th rocker arm whose position is adjustable with respect to the cylinder head is provided, the lift amount of the pallet can be changed and adjusted as appropriate. This not only improves combustion efficiency but also has the advantage of making the overall structure more compact.

[Brief explanation of drawings]

The figures show a rocker arm mechanism for an internal combustion engine as an embodiment of the present invention, FIG. 1 is a schematic diagram for explaining its principle, FIG. 2 is a perspective view schematically showing its arrangement,
FIG. 3 is a front view showing how it is arranged in an actual machine. 1...10th Tsuka Arm, 1a・Kokuzen, 2・
... Rocker shaft, 3 ... Bush rod, 4 ... 20th lock arm, 5 ...
・・Sub-valve, 6・・・needle, 7・・・Rocker arm support base, 7a・・・Slot hole, 8・・・・
...Bolt, 9...Natsuto, 10...
Cylinder head, 11°...Main rocker arm, 1
2...Middle lug shaft, 13...Main valve, 0□...Fully point of 20th lug arm, A2...
...The force point of the 20th force arm, 9...The point of action of the 20th force arm, t! 4...Fulcrum 02
Distance from to point of action, 13 Distance from fulcrum 0° to point of force A2.

Claims (1)

[Scope of utility model registration request] A 10th lever arm has one end engaged with a bushing rod for opening and closing a valve in an internal combustion engine, a 20th lever arm that contacts the other end and receives the acting force of the bushing rod, and a 20th lever arm that is pressed by the 20th lever arm. The 20th lever arm is provided with a position adjustable on the cylinder head in order to change and adjust the distance from the fulcrum to the point of force and the distance from the fulcrum to the point of action, respectively. A rocker arm mechanism for an internal combustion engine, which is characterized by: