JPS62178721A - Drum rotating type valve device - Google Patents

Abstract

PURPOSE:To improve sealing ability of a valve by providing side chamber of an exhaust passage on an exhaust port, whereby in case of opening and closing between the port and the chamber by a rotary valve, at the time of valve closing, the whole valve is pressed to the exhaust passage side by valve closing force produced by bringing the valve end portion into contact with a stopper. CONSTITUTION:A chamber 5 is provided on the side of an exhaust port 4, and connection and disconnection between the chamber and the exhaust port is conducted by a rotary valve 22. In case of low speed, the rotary valve 22 is turned clockwise by a rod 25 and an arm 12 to connect the chamber 5 to the exhaust port 4, so that pulsation wave for preventing blow-by of exhaust gas is formed. In case of high speed, the rotary valve 22 is turned counter-clockwise by the turning movement of the arm 12, so that a projection 27 mounted on the end portion of the valve is brought into contact with a stopper 26. At that time, the closing turning force of the arm 12 produces force for pressing the whole rotary valve 22 to the exhaust port 4 side centering around a contact point of the stopper 26 and the projection 27, so that strong closing force is produced between a flat plate 10 of the rotary valve 22 and the side wall 6 of the port to accomplish sealing.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a drum rotary valve device for disconnecting communication between an intake passage or an exhaust passage of an engine and a chamber formed in communication therewith.

``Conventional Technology'' As is well known, the structure of the intake and exhaust systems of a two-stroke engine has a large effect on the engine's output. This is sucking
This is because pressure waves in the exhaust system have a large effect on scavenging air.

In other words, taking the exhaust system as an example, if we consider the stage where the piston descends from top dead center, the exhaust port is opened, and then the scavenging port is opened, the pressure at which the exhaust port is open and the exhaust gas is When the gas is exhausted, that pressure is reflected by a chamber in the exhaust pipe and returns to the exhaust port.If this reflected pressure wave (dense liquid) is made to return after the scavenging port closes,
The so-called atrium can be used to push gas back, making it possible to create an engine with good filling efficiency.

By the way, as mentioned above, the charging efficiency improves only when the engine is in a specified rotation range, and when the engine rotation speed deviates from that range and the scavenging port closes and the exhaust port is about to close. Conversely, if the exhaust pressure line wave returns, the gas in the atrium increases and the gas filling efficiency decreases.

Therefore, in the past, the structure of the exhaust system was set to be suitable for either a low rotation range or a high rotation range (for example, a high rotation range), and when the engine speed was in the rotation range suitable for the exhaust system, the exhaust system If the same rotational speed deviates from that area, the main exhaust passage is connected to a subchamber that has been branched off from the main passage in advance, and the exhaust pressure wave is attenuated to reduce its influence. Therefore, exhaust systems have been devised that can provide relatively high output over a wide range from low rotational speeds to high rotational speeds.

What is shown in FIG. 1 is an example, and in the figure
2 is a cylinder block, 2 is a cylinder head, and 3 is a piston. An exhaust passage 4 is provided in the cylinder block 1, and a subchamber 5 is provided above the exhaust passage 4.

Further, a drum rotary valve device 7 is disposed on a partition wall 6 that partitions the subchamber 5 and the exhaust passage 11. This valve device 7 is rotated according to the rotational condition of the engine to open and close an opening 8 provided in the partition wall 6. As shown in FIG. A base 9.9, a plate-shaped valve body 10 passed between the bases 9, a rod 11 provided at the base on the negative side so as to protrude outward, and a rod 11 connected to the rod 11 via an arm I2. It consists of a connected drive mechanism (not shown).

According to the above exhaust system, when the engine is in a low rotation range, the drum rotary valve device 7 opens the opening 8 to communicate the subchamber 5 with the exhaust passage 4, thereby attenuating exhaust pressure waves. Therefore, in this case, engine scavenging is less affected by exhaust pressure waves. On the other hand, when the engine reaches a high speed range, the valve device 7 closes off the opening 8, and the exhaust pressure wave is not attenuated by the subchamber 5, resulting in a normal exhaust mode. The exhaust system is set in advance to obtain high output in the high rotation range, so in this case, the atrium actively uses reflected pressure waves to push the gas back and obtain high output. That will happen. That is, according to the above exhaust system, relatively high output engine characteristics can be obtained over a wide range from a low rotation range to a high rotation range.

"Problems to be Solved by the Invention" By the way, in the drum rotating valve device described above, since the valve body 10 faces the exhaust passage 4 and is easily affected by heat, deformation due to heat must be taken into consideration in advance. If it doesn't happen,
Moreover, the valve (the valve here refers to the base 9 at both ends).
In order to quickly rotate the valve (composed of the valve body 9 and the valve body 10), it is necessary to provide an appropriate clearance between the valve and the valve housing. However, if an appropriate clearance is provided, when the valve is in the closed state, the valve body IO receives a force that separates it from the valve seat 13 of the partition wall due to the exhaust pressure, so there is a gap between the valve body IO and the valve seat 13. A relatively large gap S is formed (see Fig. 1), and the exhaust passage 4 is communicated with the subchamber 5 through this gap S even though it is in the closed state, and the exhaust pressure wave is actively generated. This causes a problem in that it prevents you from using it.

As a way to deal with such problems,
No. 110610 discloses that a sealing material is disposed around the outer circumference of the valve to ensure airtightness between the valve and the valve housing, but such a method requires a new sealing material. In addition, the sealing material comes into contact with the inner surface of the valve accommodating portion and obstructs smooth rotation of the valve.

``Object of the Invention'' The present invention has been made in view of the above circumstances, and provides an object to prevent leakage between a valve and a valve seat without using a sealing material, and to allow the valve to rotate smoothly. The purpose of the present invention is to provide a drum rotary valve device that can perform the following functions.

[Means for Solving the Problems] In the valve device of the present invention, a stopper is provided on one side of the rotational axis of the valve to determine the closed position of the valve, and a stopper is provided on the other side of the rotational axis via an arm. A valve rotation driving rod is provided to rotate the valve, and when the valve is kept in a closed position, the direction in which the valve rotation driving rod is pressed and the direction of the reaction force received from the stopper coincide with the direction in which the valve body is pressed against the valve seat side. Thus, the stopper and the valve rotation driving rod are arranged.

"Embodiment" Hereinafter, a preferred embodiment of the present invention will be described with reference to FIGS. 3 to 6.

This example is an example in which the valve device according to the present invention is interposed between the exhaust passage of a two-stroke engine and a subchamber provided in communication therewith, similar to those shown in FIGS. 1 and 2. It is. In the drawings, the same components as those shown in the conventional example are given the same reference numerals to simplify the explanation.

A partition wall 6 that partitions an exhaust passage 4 and a subchamber 5 of the cylinder block 1 has an opening 8 formed in an elliptical shape when viewed from above to communicate the two (see FIG. 4). Further, an exhaust passage 4 is provided in the cylinder block 1 so as to cross the upper part of the exhaust passage 4, the partition wall 6, and the lower part of the subchamber 5.
A valve storage section 21 is provided which extends perpendicularly to the valve storage section 2! A drum rotary valve device 22 according to the present invention is disposed.

In this device, the valve 23 has a shape that fits entirely within a virtual cylindrical body, and includes a disk-shaped base 9.9 arranged at a predetermined interval at both ends, and the bases 9.9.
The valve body 10 is disposed at the lower part of the valve body 10 and is arranged parallel to the rotation center ρ of the valve 23, and a half-moon-shaped rib 24 is provided in parallel above the valve body 10 at a predetermined interval. There is.

The valve body IO is appropriately curved so as to be continuously connected to the partition wall 6 that partitions the exhaust passage 4 around the valve and the subchamber 5 without forming a step when the valve body IO is in the closed state. There is.

Further, the portion 10a of the valve body 10 that contacts the valve seat 13 and the valve seat 13 are each formed into a circular arc shape centered on the rotation center Q of the valve 23 so as to be in close contact with each other.

That is, in the closed state, the valve body 10 cooperates with the exhaust passage partition wall 6a around the valve to form an exhaust passage having a smooth, substantially arc-shaped cross section with no irregularities.

A rod 11 is provided at the base of one of the two store portions 9 and extends outward from the center of the base, and an arm 1 is provided at the end of the rod 11 that protrudes outward from the cylinder block l.
2 are connected. One end of a valve rotation driving rod 25 is rotatably connected to the tip of this arm 12, and the other end of the valve rotation driving rod 25 operates according to the rotation speed of the engine, such as a governor. A valve drive mechanism is connected. In other words, the rotational condition of the engine is
r-r += -r IN ff1h ITI r-v
,,, V Q C, A(”N Q Ti?+ rh
- The movement of the rod 25 is transmitted to the valve 23 via the arm I2, whereby the valve 23 is rotated in the left-right direction.

Additionally, there is a stop on the outside of the valve base 9 on the other side.

A collar 26 is attached. This stopper 26 is
When the valve is rotated in the closing direction, the closed position of the valve 23 is determined by pressing the projection 27 attached to the valve base 9 with the lower surface 26a of the stopper. The stopper 26 and the valve rotation driving rod 25 are
When viewed from the side, the center of rotation a of the valve is as shown in Figure 3.
A stopper 26 is provided on one side of the rotation center Q, and a rod 25 is provided on the other side so as to sandwich the rotation center Q. Moreover, when the stopper 26 and the valve rotation driving rod 25 keep the valve in the closed position, the pressing direction of the valve rotation driving rod and the direction of the reaction force generated by the stopper 26 are
In this exhaust system, an exhaust pipe (not shown) is connected to the exhaust passage 4, and the engine is connected to this exhaust pipe. There are exhaust chambers with a set capacity and length so that high output can be obtained when the engine rotates at high speeds.

Next, the function of the valve device 22 will be clarified while explaining the function of the exhaust system having the above configuration.

When the engine is in a low rotation range, the valve 23 is operated by the drive mechanism to rotate by an appropriate angle, and is opened as shown in FIG. 6, thereby communicating the exhaust passage 4 with the subchamber 5. Therefore, the exhaust pressure wave is transmitted to this subchamber 5.
Part of the wave is branched, and when the waves in the subchamber 5 join the exhaust passage 4, both waves cancel each other out, so the exhaust pressure wave Attenuated. As a result, engine scavenging air is not easily affected by exhaust pressure waves, and there is no problem that the gas in the atrium increases and the output decreases.

On the other hand, when the engine reaches a high speed range, the valve 23 is operated by the drive mechanism and becomes closed as shown in FIGS. .

As mentioned above, the exhaust system is set to obtain high output in a high rotation range, and therefore, the desired high output can be obtained.

Further, in this example, when the valve 23 is kept in the closed state, the valve drive mechanism is continuously operated to keep pressing the valve drive rod 25 downward.

During this time, although the valve 25 is subjected to a force of rotation in the counterclockwise direction around the rotation center ρ in FIGS. The rotation is blocked by the rotor. Therefore, the downward pressing force acting on the valve driving rod 25 is applied to the pulp 23 using the protrusion 27 that is supported in contact with the stopper 26 as a fulcrum.
This acts as a force that rotates the valve 23 in the counterclockwise direction, so that the valve 23 is pushed toward the exhaust passage 4 against the pressure of the exhaust gas, and its side end is strongly abutted against the valve seat 13. As a result, leakage from the exhaust passage 4 to the subchamber 5 can be reliably prevented.

In the above embodiment, the valve 23 is provided with a reinforcing rib 24, but the rib 24 may be omitted if sufficient strength can be obtained only from other valve components.

Further, the valve device according to the present invention is not installed only on the exhaust passage 4 side, but can also be installed between the intake passage and a subchamber communicating therewith.

``Effects of the Invention'' As explained above, according to the present invention, the force that closes the valve is used, and this force allows the valve itself to be brought into close contact with the valve seat, so that the valve and the valve housing can be brought into close contact with each other. It is possible to secure sufficient sealing performance for the valve without using a special sole member, while ensuring sufficient clearance to smoothly rotate the valve between the two.

[Brief explanation of drawings]

Fig. 1 and Fig. 2 show a conventional example, and Fig. 1 shows a drum valve h < IrVM size l+^h, f-, x so...
A vertical cross-sectional view showing the drain passage of the bus, Figure 2 is the same as in Figure 1.
3 to 6 show an embodiment of the present invention, FIG. 3 is a longitudinal sectional view of the main parts of the engine, and FIG.
The figures are cross-sectional views taken along line IV-IV in Figure 3, Figures 5 and 6.
The figure is a partial sectional view for explaining the action. ! ... Cylinder block, 3 ... Piston, 4 ... Exhaust passage, 5 ... Subchamber, 12 ... Arm, 13 ... ... Valve seat, 22 ... Valve device, 23 ...
... Valve, 25 ... Valve rotation drive rod, 26 ... Stopper, 27 ... Protrusion.

Claims (1)

[Claims] The valve body is interposed between the intake passage or exhaust passage of the engine and a chamber formed in communication therewith, and is operated to rotate around its axis, and when the valve body reaches a predetermined rotational position, the valve body moves into the intake passage or exhaust passage. A drum rotary valve device for blocking a communication path between the valve and the chamber, wherein a stopper is provided on one side of the valve rotational axis to determine the closed position of the valve, and a stopper is provided on the other side of the rotational axis of the valve. A valve rotation driving rod is provided to rotate the valve via an arm, and when the valve is kept in the closed position, the direction in which the valve rotation driving rod is pressed and the direction of the reaction force received from the stopper are such that the valve body is directed toward the valve seat side. A drum rotary valve device, wherein the stopper and the valve rotation driving rod are arranged so as to coincide with a pressing direction.