JPS6345522Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a valve mechanism for a multi-cylinder internal combustion engine, and in particular, when the engine is in operation or at low or medium load, when stopping the operation of some cylinders, the intake and exhaust valves are activated. This relates to a valve train that can stop the engine.

Generally, when an internal combustion engine is at a so-called low load with surplus output, such as when idling or when going downhill, the pumping loss in the compression process increases and the fuel consumption rate worsens.

Therefore, as an improvement measure for this, in the case of conventional multi-cylinder internal combustion engines, by stopping the operation of some cylinders during low to medium load, it is possible to create a high load operating state and improve the fuel consumption rate. has been measured.

As a means to stop the operation of some cylinders in this multi-cylinder internal combustion engine, in the case of electronically controlled fuel injection engines, a method has been used to temporarily stop fuel injection. It cannot be used in equipped engines, and even in cylinders where fuel injection is stopped, the intake and exhaust valves operate as usual, so air is sucked in and discharged as the piston operates. However, pumping losses still remain unavoidable.

Therefore, in recent years, attempts have been made to stop the operation of some cylinders by forcibly increasing the gap between the rocker arm and the valve. It's about to happen.

However, even with this method of stopping the valve operation by forcibly increasing the gap between the rocker arm and the valve, no valve train mechanism that can operate satisfactorily has been developed at present, so this development is difficult. This has become an urgent task.

In view of this situation, the present applicant has previously filed an application (Utility Application No. 130951/1983) to provide this type of excellent valve mechanism, but subsequent research has revealed that it can operate even more safely and reliably. We have devised a valve train for an internal combustion engine that achieves this goal, and we now offer this.

In other words, regarding the valve mechanism for an internal combustion engine that was previously filed, as shown in FIG.
The valve 8 is opened and closed by contacting and swinging the push rod 7 (cam in the case of OHC). First of all, Rotsukashaft 12
The first bush 3 is fitted with an eccentricity e in the downward direction on the Y--Y line passing through the shaft center with respect to the shaft center of the rocker shaft. A second bush is fitted onto the first bush 3 so as to be eccentric by e on the Y-Y line in the same direction as the eccentric direction of the first bush with respect to the axis of the first bush. To explain the principle with reference to Fig. 2, the first bush 3 and the second bush
By rotating and controlling the bushes 4 at the same angle with respect to the axis of the rocker shaft 2 in mutually opposite directions at the same time (the first bushing is rotated clockwise and the second bushing 4 is rotated counterclockwise), the rocker arm R is vertically rotated. By moving it upward, the rocker arm is separated from the valve 8.

Further, as shown in FIG. 2, the axes of the first bushing 3 and the second bushing 4 are fitted and assembled eccentrically on the same line Y-Y with respect to the axis of the rocker shaft 2. Therefore, when the valve in contact with the rocker arm is in the state of intake/exhaust operation due to rocking of the rocker arm, the F
The rocker arm can maintain its normal position in a stable state even when applied with a load in any direction.

Next, its operating state will be sequentially explained. 1st
In the figure, a transmission member 5 is fitted to the rocker shaft 2, a pin 41 is attached to the second bush 4, and a groove 52 (hole is provided at an arbitrary location of the transmission member 5) to allow the pin to fit. (You may do so.)
The pin 41 is fitted into the transmission member, so that the transmission member and the second bushing are configured to interlock with each other. Connecting pins 31 are placed on the first bushing 3 and the transmission member 5 at positions equidistant from the axis of the rocker shaft, respectively.
51, and links 6, 6 of equal length are connected to the connecting pins 31, 51, the other ends of the links are connected at the same fulcrum 9, and the same fulcrum 9 is connected to the air cylinder 10. There is. In the case of Fig. 2, valve 8 is in contact with rocker arm R.
Although the air intake and exhaust operations are carried out by the rocking of the rocker arm, in order to stop the operation of some cylinders during operation of a multi-cylinder internal combustion engine or at low or medium load, there is a mechanism installed in the air cylinder 10. By moving the piston 11 vertically upward by sending pressurized air through the lower air supply hole 13, the same fulcrum 9 connected to the piston rod 12 also moves, and the first bush 3 is moved through the links 6, 6. Then, the second bushing 4 is simultaneously rotated in opposite directions at the same angle with respect to the axis of the rocker shaft 2 via the transmission member 5 (the first bushing is clockwise, the second bushing is counterclockwise), and the rocker arm R is rotated vertically upward. Therefore, even if the locker arm R is swung by the push rod 7, the valve 8 will not operate, and the operation of some cylinders will be stopped during operation of the multi-cylinder internal combustion engine. . Conversely, in order to restart a partially stopped cylinder, the air forced through the lower air supply hole 13 of the air cylinder 10 is released, and pressurized air is sent through the upper air supply hole 14 to move the piston 11 vertically downward. As a result, the rocker arm R and the valve 8 come into contact with each other, and intake and exhaust operations are performed by normal swinging of the rocker arm.

As described above, the rocker arm R valve 8 is finally separated or connected due to the vertical movement of the piston 11 due to air being forcedly fed from the lower air supply hole 13 or the upper air supply hole 14 of the air cylinder 10. . However, if pressurized air is no longer supplied due to a failure in the air supply device of the air cylinder 10 while the engine is running, the piston 11 of the air cylinder 10 will not be able to determine the stopping position and will be in a halfway state, causing engine combustion to stop. There is a risk that the valve may become incomplete and the valve may break, resulting in an accident while the vehicle is running.

This invention further improves the valve mechanism for internal combustion engines that was previously applied for, and makes it possible to perform intake and exhaust operations with the rocker arm and valve in contact even if the air cylinder supply source fails, making it safe. The present invention proposes a valve mechanism for an internal combustion engine that can operate reliably.

That is, the first bushing is fitted onto the rocker shaft eccentrically downwardly on the Y-Y line passing through the shaft center with respect to the shaft center of the rocker shaft;
on the bushing with respect to the axis of the first bushing.
A second bushing is fitted eccentrically on the Y-Y line in the same direction as the eccentric direction of the bushing, and a rocker arm is loosely inserted onto the second bushing, and the first bushing and the second bushing are connected to the axis of the rocker shaft. In a driving mechanism for an internal combustion engine, the first bushing and the second bushing are configured to separate the rocker arm from the valve by rotating and controlling the rocker arm in opposite directions simultaneously at the same angle with respect to the center.
Two links are provided which respectively interlock with the bush, the other end of each link is connected at the same fulcrum, and the same fulcrum is connected to the piston rod of the air cylinder, and when the piston rod moves in one direction, the link moves to the first rotating the bushing and the second bushing in a direction in which the rocker arm disengages from the valve; and when the piston rod moves in the opposite direction, the link rotates the first bushing and the second bushing in a direction in which the rocker arm contacts the valve; A support member is provided on the piston rod near the same fulcrum of each link, and an elastic member is provided between the support member and the outer wall of the air cylinder to press the piston rod in the opposite direction. It is something.

Embodiments of the present invention will be described in detail below with reference to the drawings.

As shown in FIG. 3, in the air cylinder 10, a support member 16 is provided on the piston rod 12 near the same fulcrum 9 of the two links 6, 6, and an elastic member 16 is provided between the support member and the lower outer wall of the air cylinder. A coil spring 15 as a member is provided. In this case, the elastic force of the coil spring 15 is
The piston 11 of the air cylinder 10 is set to operate so as to be located at the lowest point. That is, the valve operating mechanism is in such a state that the rocker arm R is in contact with the valve 8, and the rocker arm R swings to perform intake and exhaust operations. When a multi-cylinder internal combustion engine is in operation, at low or medium loads, to stop the operation of some cylinders, the piston 11 is raised by pumping air through the lower air supply hole 13 of the air cylinder 10, The same fulcrum 9 is moved vertically upward, and then the rocker arm R is moved vertically upward according to the principle explained in FIGS. 1 and 2, and the rocker arm R is separated from the valve 8. Therefore, the rocker arm R is Even if the push rod 7 swings, the valve 8 will not operate.
Conversely, when returning to normal operating conditions, the air forced through the lower air supply hole 13 is released, and pressurized air is fed into the air cylinder through the upper air supply hole 14 to move the piston 11 vertically downward. As a result, the rocker arm R and the valve 8 come into contact with each other, and normal rocking of the rocker arm R allows intake and exhaust operations to be performed. In the above description, in FIG. 3, the upper air supply hole 1
4 is a mere air escape hole, and when the piston 11 is to be raised, air is forced to be delivered from the lower air supply hole 13, and conversely, when the piston 11 is to be lowered, the air is supplied from the lower air supply hole 13. When the air forced through the hole 13 is released, the piston 11 is automatically lowered by the elastic force of the coil spring 15. However, the elastic force of the coil spring 15 alone is affected by the frictional force between the piston 11 and the inner wall of the air cylinder, resulting in poor responsiveness. It is more effective to lower the piston 11 using the elastic force of .

As shown in FIG. 4, by providing a coil spring 15 in parallel between the support member 16 and the lower outer wall of the air cylinder, more elastic force is exerted and responsiveness is improved. Furthermore, as shown in FIG. 5, even when the coil spring 15, which is the elastic member, is provided between the piston 11 and the inner wall of the upper part of the air cylinder in the air cylinder 10, the same effect as in the case of FIG. Effects can be obtained.

Furthermore, in FIGS. 3 to 5, the air cylinder 1
0, lower air supply hole 13 and upper air supply hole 14
However, as shown in FIG. 6, the air cylinder 10 is provided with only a lower air supply hole 13, and when the piston 11 is located at the highest point inside the air cylinder, the piston 11 and the upper part of the air cylinder are The piston 11 is arranged so that a partial space 17 is formed between it and the inner wall in which compressed air is held.
is formed into a convex shape. In this case, when the piston 11 is raised, pressurized air is sent from the lower air supply hole 13, and when the piston 11 is lowered, the pressurized air is released from the lower air supply hole 13, and the coil spring 15 is The piston 11 can be lowered by the elastic force and the compressed air force forced into the partial space,
The same effect as the mechanism explained in FIGS. 3 to 5 can be obtained. In FIG. 6, the piston shape is made convex in order to provide a partial space between the piston 11 and the upper inner wall of the air cylinder, but it goes without saying that this may be provided on the air cylinder side and is not limited to this. .

Since the present invention has the configuration as explained above, even if the air supply device stops working due to some kind of failure, the elasticity of the coil spring, which is an elastic member, is reliably maintained regardless of the position of the piston. The force returns the piston to its lowest point.
Therefore, it is possible to perform intake and exhaust operations while the locking arm and the valve are in contact with each other, and in the valve mechanism of a multi-cylinder internal combustion engine, it is possible to perform the intake and exhaust operations in a valve mechanism of a multi-cylinder internal combustion engine, especially when the engine is operating at low or medium load. When stopping operation, it can operate smoothly, safely, and reliably. Furthermore, the valve operating mechanism maintains a stable holding state of the rocker arm even during normal valve operation, and has excellent effects.

[Brief explanation of the drawing]

Fig. 1 is a partial cross-sectional front view showing the valve train mechanism applied for earlier, Fig. 2 is a schematic partial cross-sectional view showing the valve train mechanism applied for earlier, and Figures 3 to 6 are examples of the present invention. FIG. 2 shows a partially sectional front view showing a certain valve mechanism. Explanation of the numbers, R...Rotsuka arm, 2...Rotsuka shaft, 3...First bushing, 4...Second bushing, 5...Transmission member, 6...Link, 7...
Push rod, 8... Valve, 9... Same fulcrum, 10... Air cylinder, 11... Piston,
12...Piston rod, 13...Lower air supply hole, 14...Upper air supply hole, 15...Coil spring, 16...Support member.

Claims (1)

[Claims for Utility Model Registration] (1) A first bushing is fitted onto the locking shaft eccentrically downward on the Y-Y line passing through the axis with respect to the axis of the locking shaft; A second bushing is fitted eccentrically on the Y-Y line in the same direction as the eccentric direction of the first bushing with respect to the axis of the first bushing, and a rocker arm is loosely inserted onto the second bushing. , an internal combustion engine configured to rotate and control the first bushing and the second bushing at the same angle with respect to the axis of the rocker shaft in mutually opposite directions at the same time, so that the rocker arm is separated from or brought into contact with the valve. In the valve operating mechanism, two links are provided which respectively interlock with the first bushing and the second bushing, the other ends of each link are connected at the same fulcrum, and the same fulcrum is connected to the piston rod of the air cylinder,
When the piston rod moves in one direction, the link rotates the first and second bushes in a direction in which the rocker arm disengages from the valve, and when the piston rod moves in the opposite direction, the link rotates the first and second bushes. The bush is rotated in a direction in which the rocker arm contacts the valve, a support member is provided on the piston rod near the same fulcrum of each link, and the piston rod is rotated in the opposite direction between the support member and the outer wall of the air cylinder. A valve mechanism for an internal combustion engine, characterized in that it is provided with a pressing elastic member. (2) The valve mechanism for an internal combustion engine according to claim 1, wherein the air cylinder is provided with an upper air supply hole and a lower air supply hole. (3) In the air cylinder, when the piston is held in a position where it contacts the upper inner wall of the air cylinder, there is a partial space between the piston and the upper inner wall of the air cylinder in which compressed air is held. The valve operating mechanism for an internal combustion engine according to claim 1, further comprising a lower air supply hole. (4) In the air cylinder, the piston and/or
Alternatively, the valve operating mechanism for an internal combustion engine according to claim 3, wherein the upper inner wall of the air cylinder has a convex or concave shape.