JP7009206B2 - Rotary valve mechanism and ventilation valve and drainage pipe system using this - Google Patents

Description

The present invention relates to a rotary valve mechanism, a ventilation valve for eliminating a negative pressure generated in a water distribution pipe of a drainage facility using the rotary valve mechanism, and a drainage pipe system.

Conventionally, for example, in drainage facilities of buildings such as individual houses and apartment houses, a vent valve is used to protect the trap water of the drainage device and eliminate the negative pressure in the drain pipe to ensure smooth drainage. The drainage system that was used is generally known.

As a vent valve used in this type of drainage pipe system, for example, the safety valve of Patent Document 1 is disclosed. In this valve, the housing is connected to the ventilation pipe, and a valve seat is provided in the inner chamber inside the housing. A valve body that moves up and down due to pressure fluctuations is separated from the valve seat, and an annular seal member provided on the valve body is provided in a structure that opens and closes the intake flow path.
In this valve, normally, the valve body is seated on the valve seat by its own weight to keep the ventilation pipe closed. On the other hand, when a negative pressure is generated in the drain pipe, the valve body lifts up from the valve seat against its own weight due to the pressure difference with the atmosphere, and the atmosphere is taken into the drain pipe through the vent valve in the valve open state. Negative pressure is reduced.

Further, for a vent valve having the above structure, a vent valve in which a compression spring is added between the valve body and the cap has also been proposed. In this vent valve, in addition to the weight of the valve body when the valve is closed, the elastic force of the compression spring is exerted to maintain the valve closed state.

On the other hand, in the ventilation device of Patent Document 2, the valve body is mounted in the body in a cantilevered support state via the shaft attachment portion, and the valve seat packing provided on the valve body is in contact with the diagonal valve seat surface in the body. It is provided so that the valve can be opened and closed separately.
In the case of this ventilation device, the valve body always rotates around the bearing portion due to its own weight and sits on the valve seat to close the valve. On the other hand, when the drainage pipe becomes a negative pressure, the valve body rotates around the bearing portion due to the differential pressure to open the valve, and the negative pressure is reduced.

Special Fair 1-376228 Gazette Japanese Patent No. 3490413

In the case of the vent valve of Patent Document 1, since the valve body is in a valve closed state due to its own weight, the valve closing force, that is, the force acting in the valve closing direction depends on the valve body's own weight, and the valve opening degree. Regardless of this, the magnitude of the valve closing force becomes a constant value.
When a negative pressure is generated, the valve body rises to perform ventilation, and a cylindrical ventilation area corresponding to the valve diameter area is secured with a small lift amount of the valve body to alleviate the negative pressure. In the process of relaxing the negative pressure, the valve body tries to descend in the valve closing direction, but the drainage in the drainage pipe continues to flow for a while depending on the usage of drainage equipment such as toilets and wash basins, and the flow is constant. Since it is not always the case, the negative pressure is attenuated while changing. When the force by which the valve body is lifted by this negative pressure, that is, the valve opening force is larger than the valve closing force due to the weight of the valve body, the valve body rises again against the valve closing force. In this way, in the case of a vent valve that closes the valve only by its own weight of the valve body, only a certain valve closing force by its own weight works in the valve open state, so when the negative pressure changes, the valve due to this changing negative pressure. It becomes difficult for the body to maintain a constant open state. As a result, the valve body repeatedly rises (valve opening operation) and descends (valve closing operation) due to a slight negative pressure change, so that the valve body frequently contacts the valve seat, so-called chattering phenomenon is likely to occur. Become. Then, the valve opening tends to fluctuate due to the pressure fluctuation in the drain pipe, the balance of the force in the ascending / descending direction at the time of valve opening is suddenly lost, the force in the valve closing direction acts, and the valve closing operation is performed by the own weight of the valve body. The momentum may be stronger.

Further, in the case of a vent valve having a structure in which a compression spring is attached to the valve body of the above vent valve, the valve closing force is further increased by applying the elastic force of the compression spring in addition to the weight of the valve body when fully closed. growing. Therefore, when a negative pressure is generated, the elastic force of the compression spring increases proportionally as the valve opening degree increases, and the valve closing force increases proportionally. For this reason, it becomes easier to close the valve body easily before the negative pressure is completely eliminated from the intermediate opening or when it is fully opened, the momentum of this valve closing operation is further strengthened by the compression spring, and the responsiveness to the generation of negative pressure is also poor. Therefore, the chattering phenomenon is more likely to occur.

In the ventilation device of Patent Document 2, since the valve closing force has a structure that is increased by the rotational moment of the valve body, the valve closing force becomes the largest when fully closed. Therefore, at the time of intermediate opening or full opening, the valve body tends to close at an accelerating rate when the negative pressure is eliminated, and chattering due to a change in the negative pressure tends to occur.
In this case, the valve closing force becomes a rotational moment based on the weight of the valve body and the distance of the valve body weight center from the rotation axis, and decreases as the opening degree of the valve body increases. Therefore, for example, if the valve opening is increased to the vicinity of the valve body opening at full angle, it becomes difficult to close the valve when the negative pressure is eliminated. For example, if the valve opening exceeds 70%, the negative pressure decreases. The prompt valve closing operation that accompanies it becomes difficult. As described above, since the valve body in the fully open state has a structure that hinders the reduction of the negative pressure, it is necessary to set the ventilation port diameter to a large diameter in order to secure the ventilation amount, and the whole becomes large.

The present invention has been developed to solve the conventional problems, and an object thereof is a rotary valve mechanism that opens and closes a flow path when a negative pressure is generated to eliminate the negative pressure, and changes in the negative pressure. It is an object of the present invention to provide a new rotary valve mechanism that keeps the valve body in a stable state and suppresses the chattering phenomenon, and a vent valve and a drainage pipe system using the mechanism.

In order to achieve the above object, the invention according to claim 1 is a rotary valve mechanism for opening and closing a flow path by a rotary valve body, in which the peak of the valve closing force of the rotary valve body is opened from the valve opening fully closed. It is a rotary valve mechanism that suppresses the chattering phenomenon between the rotary valve body and the valve seat by setting it while the valve seat is fully open.

The invention according to claim 2 is a rotary valve mechanism in which the peak of the valve closing force of the rotary valve body is set between the valve opening degree of 5% and 50%.

The invention according to claim 3 is a rotary valve mechanism having a double eccentric structure in which the rotation center of the rotary valve body is doubly eccentric.

The invention according to claim 4 is a rotary valve mechanism in which the eccentricity of the valve body support portion that supports the rotary valve body with respect to the rotary valve body is 40% or more.

The invention according to claim 5 is a rotary valve mechanism in which the rotary valve body is arranged at a position where the valve is opened by the weight of the disc body, and the valve is closed due to the balance with the weight portion provided on the disc body.

The invention according to claim 6 is a vent valve using a rotary valve mechanism.

The invention according to claim 7 is a drainage pipe system in which a vent valve is mounted on an extension vent pipe or a lower part of an overflow edge.

According to the first aspect of the present invention, when a negative pressure is generated inside, the rotary valve body opens and closes the flow path to eliminate the negative pressure. At that time, by setting the peak of the valve closing force of the rotary valve body between the valve opening fully closed and the valve opening fully opened, the valve body tries to maintain the state of this intermediate opening, and the negative pressure changes. Even if it occurs, it can operate in a stable state. As a result, it is possible to provide a new rotary valve mechanism capable of reliably eliminating the negative pressure while suppressing the chattering phenomenon due to the repetition of the minute opening / closing operation of the rotary valve body during the valve body operation including the time when the valve is slightly opened.

According to the second aspect of the present invention, by setting the peak of the valve closing force of the rotary valve body between 5% and 50% of the valve opening degree, the rotary valve body can be reliably returned to the valve closed state. , The valve closing force of the rotary valve body can be set to the maximum at the intermediate opening. If the rotary valve body has a slight opening range near the fully closed position, the balance state of the rotary valve body is maintained to prevent seating even when the negative pressure fluctuates, and the chattering phenomenon is prevented.

According to the third aspect of the present invention, the sliding range between the valve body seal side and the valve seat seal side during the opening / closing operation of the rotary valve body is suppressed very slightly to reduce their contact resistance, and the contact resistance is lowered while preventing wear. It is possible to smoothly open and close the rotary valve body with torque, and it exhibits high sealing performance when the valve is closed.

According to the invention of claim 4, the weight on the valve closing side and the weight on the valve opening side of the disc body with respect to the valve body support can be functionally separated, and the eccentricity of the valve body support with respect to the rotary valve body can be used. Normally, the valve closed state is surely maintained, and even when pressure fluctuations occur, the characteristics of the closing direction torque due to the valve body weight with respect to the valve opening torque are increased to prevent the occurrence of chattering phenomenon and stable valve closing. The state can be maintained. When negative pressure is generated, the rotary valve body prevents the valve closing operation due to unbalance torque via the valve body support part and smoothly opens the valve to eliminate the negative pressure, and after the negative pressure is eliminated, the rotary valve body Operates slowly and returns to the valve closed state.

According to the fifth aspect of the present invention, normally, a force in the valve closing direction is applied to the rotary valve body due to the balance with the weight portion to maintain the valve closed state in a stable state. When a negative pressure is generated, a force in the valve opening direction is applied to the rotary valve body, so that the rotary valve body smoothly opens the valve against the weight of the weight part, and opens and closes while exhibiting high responsiveness in response to pressure fluctuations. Operate.

According to the invention of claim 6, it can be attached to the ventilation pipe of the drainage pipe system, and when it is attached, it can be installed in a narrow piping space while saving space. When the internal pressure is at atmospheric pressure or when a positive pressure is generated inside, the valve closed state can be maintained and the sealing property can be ensured. On the other hand, when a negative pressure is generated in the main body, the ventilation resistance is suppressed to secure a large amount of ventilation, and the high responsiveness allows smooth operation until the valve is opened. As a result, it is possible to provide a ventilation valve that can suppress the chattering phenomenon, sufficiently inhale the atmosphere from the outside at the time of negative pressure and surely eliminate it, and prevent noise at the time of drainage and leakage of odor to the outside.

According to the invention of claim 7, the negative pressure inside the drainage horizontal branch pipe and the drainage stand pipe connected to the drainage device by attaching to the extension ventilation pipe of the drainage facility installed in the individual house or the apartment house is released to the atmosphere. It can be done, or it can be attached to the lower part of the overflow edge of the drainage device to eliminate the negative pressure generated in the individual drainage device. As a result, it is possible to smoothly drain water while suppressing drainage noise while preventing odor leakage by arranging it at a preferable position of drainage facilities having various structures piped to individual houses or apartment houses.

It is a schematic diagram which shows an example of a drainage pipe system. It is a central vertical sectional view which shows the 1st Embodiment using the rotary valve mechanism of this invention as a vent valve. It is a central vertical sectional view which shows the valve open state of the vent valve of FIG. It is a top view which shows the state which removed the cover of FIG. It is a separation perspective view of the ventilation valve of FIG. It is a schematic diagram of the vent valve of FIG. It is a schematic diagram which shows the ventilation device of the comparative example. It is a graph which shows the relationship between a valve opening degree and a valve closing force. (A) is another graph showing the relationship between the valve opening degree and the valve closing force. (B) is a graph showing the change in the magnitude of the negative pressure from the generation of the negative pressure to the time when the negative pressure is eliminated. It is a central vertical sectional view which shows the 2nd Embodiment of a vent valve. It is a central vertical sectional view which shows the valve open state of the vent valve of FIG. It is a central sectional view which shows the 3rd Embodiment of a vent valve. It is a central vertical sectional view which shows the valve open state of the vent valve of FIG.

Hereinafter, the rotary valve mechanism, the ventilation valve using the rotary valve mechanism, and the drainage pipe system according to the present invention will be described in detail based on the embodiments. FIG. 1 shows an example of a drainage pipe system, and FIGS. 2 to 5 show a first embodiment in which the rotary valve mechanism of the present invention is used as a vent valve. A vent valve having a rotary valve mechanism (hereinafter referred to as a valve main body 100) is provided in the drainage pipe system (hereinafter referred to as a system main body 2) shown in FIG.

In FIG. 1, the system main body 2 is provided between the outer wall 5 and the inner wall 6 in, for example, an individual house or an apartment house, and in the system main body 2, the valve main body 100 is located from the drain pipe 3 to a position lower than the ceiling 7. It is attached to the extended extension ventilation pipe 4 or the lower part of the overflow edge of the drainage device. As a result, the negative pressure generated in the drain pipe 3 via the system main body 2 can be eliminated. In this embodiment, an example in which the valve main body 100 is provided in the extension ventilation pipe 4 of the system main body 2 will be described.

The extension ventilation pipe 4 is provided so as to extend above the drainage stand pipe 3a of the drainage pipe 3, and the valve body 100 is connected to the tip end side of the extension ventilation pipe 4. A drainage lateral branch pipe 3b is branched and provided at a position lower than the extension ventilation pipe 4 of the drainage vertical pipe 3a, and a drainage device 8 is provided on the primary side of the drainage lateral branch pipe 3b. An inspection port 6a is provided at an appropriate position on the inner wall 6, and the inspection port 6a is provided with a shield member 9 that is detachable and can take in outside air into the space between the outer wall 5 and the inner wall 6 as shown by cross-hatching. It is installed. By removing the shielding member 9 from the inspection port 6a, the valve main body 100 can be inspected or replaced from the inspection port 6a. Further, since the valve body 100 has substantially the same diameter as the extension ventilation pipe 4, it can be installed by adding work to the existing drainage pipe 3 or ventilation pipe 4, and is attached between the outer wall 5 and the inner wall 6 of the existing house. be able to.

As described above, the rotary valve mechanism of the present invention is applied to, for example, a vent valve (valve body 100) and is operated by a fluid composed of air. In FIGS. 2 to 5, the valve body 100 has a valve unit 110, a body 111, a cap 112, and a cover 113, and is provided so as to be shared with, for example, an extension vent pipe 4 having sizes 40A and 50A.

Of the valve body 100, the valve unit 110 includes a cylinder body 120, a seat 21 which is an annular valve seat, a rotary valve body 121 which is a disc-shaped valve body, an eccentric shaft (hinge) 122, and a weight portion 123. Is integrally incorporated, and the rotary valve body 121 is rotatably provided about the eccentric shaft 122. Due to this integrated unit structure, the valve body 100 has a vent valve function of eliminating the negative pressure in the drain pipe 3.

In this case, the valve body 100 becomes a rotary valve mechanism in which the rotary valve body 121 swings and the flow path is opened and closed by the pressure difference due to the rotary valve body 121. The rotary valve body 121 is provided so that the peak of the valve closing force, that is, the peak of the force acting in the valve closing direction is set between the valve opening fully closed (excluding fully closed) and the valve fully opened. This provides a rotary valve mechanism that suppresses the chattering phenomenon between the rotary valve body 121 and the valve seat.

Further, it is preferable that the peak of the valve closing force of the rotary valve body 121 is set between the valve opening degree of 5% and 50%. Here, the valve opening degree θ of the rotary valve body 121 means that when the fully closed seal state with the seat 21 is 0% and the fully open state is 100%, the disc main body 140 described later refers to this fully closed seal state. The opening ratio to be formed.
In the present embodiment, the valve body angle in the fully open state is set to 80 °, which will be described later, and the peak of the valve closing force of the rotary valve body 121 is set to the valve body angle of 20 °, that is, the valve opening degree of 25% (20 ° / 80 ° ×). 100 = 25%) is set.

The cylinder body 120 of the valve unit 110 is provided with a resin material such as ABS resin, and the ventilation flow path 30 that can be inserted into the mounted position of the body 111 is made of a straight-shaped substantially cylindrical cartridge body. In FIG. 2, an annular sheet 21 is provided on the upper surface of the cylinder body 120 so that it can be placed.

In the valve body 100 having the valve unit 110, as will be described later, the rotary valve body (disk-shaped valve body) 121 for the vent valve rotates in the valve closing direction with the rotational moment Mo in which the rotary valve body (disk-shaped valve body) 121 rotates in the valve opening direction. It has a rotational moment Mc.

As shown in FIGS. 4 and 5, two mounting holes 130 and 130 for mounting the eccentric shaft 122 are formed through the outer cylinder portion of the cylinder body 120. The mounting hole 130 is located at a position deviated from the center P1 of the diameter of the cylinder body 120 (eccentric position) and deviated from the valve body spherical surface 143 (seal center) described later of the rotary valve body 121 (eccentric). Position) is set based on the center P3 of the valve body support portion 141.

A protrusion 131 having a predetermined size and projecting to the inner diameter side is formed around the inner peripheral side of the mounting hole 130, and the protrusion restricting portion 132 is provided on the protrusion 131. On the other hand, on the outer periphery of the cylinder body 120, a convex portion 133 for engaging and fixing the cap 112 is intermittently formed in the circumferential direction thereof.

The valve opening restricting portion 132 is formed in a tapered surface shape, and the amount of rotation thereof can be regulated by abutting the rotary valve body 121 at the time of valve opening. The valve opening restricting portion 132 is provided at a position outside the flow path as shown in FIG. 4 in order to reduce the ventilation resistance, and the vicinity of the outer peripheral edges on both sides of the rotary valve body 121 in the fully open state is brought into contact with the valve opening restricting portion 132. These are provided so as to be supportable.

In FIG. 2, the angle δ of the valve opening restricting portion 132 from the horizontal plane of the valve seat is set to the maximum size that can secure the rotational moment Mc when the rotary valve body 121 rotates in the valve closing direction, and in the present embodiment, it is provided. , This angle δ is provided at approximately 80 °. The length X of the valve opening restricting portion 132 is provided to a size capable of preventing local deformation of the rotary valve body 121, and further, the vicinity of the outer peripheral edge portion of the rotary valve body 121 can be supported in the inner diameter direction. By making the size of the protrusion suppressed, the ventilation resistance at the time of valve opening is reduced and a large amount of ventilation is secured.

With such a configuration, the valve opening restricting unit 132 can regulate the rotary valve body 121 at the time of valve opening by a maximum angle δ (approximately 80 °). Further, the valve opening restricting portion 132 is provided at a position where the rotary valve body 121 can return to the valve closed state by balancing with the weight portion 123 when the negative pressure is released. In the present embodiment, the angle δ is set to about 80 °, but this is set based on the balance between the rotational moment Mo and the rotational moment Mc and the rotational frictional force of the valve body support portion 141, and is set based on the rotational friction force of the weight portion 123. It is also possible to make it approximately 90 ° by changing the weight.

The sheet 21 is made of a rubber material such as EPDM, is provided with a size substantially the same as the outer diameter of the cylinder body 120, and can be placed on the upper surface of the cylinder body 120, and the cylinder body 120 and the cap. It is provided to a thickness that can be sandwiched between 112 and 112. A conical tapered surface 134, which is a sealing surface with the rotary valve body 121, is formed on the sheet 21 at a predetermined taper angle. The apex of the cone (not shown) formed by the conical tapered surface 134 is provided so as to be located on the axis of the diameter of the cylinder body 120. The sealing surface of the sheet 21 may be a conical rounded surface in addition to the conical tapered surface 134.

The rotary valve body 121 is provided with a resin material such as ABS resin, and has a disc main body 140 provided in a thin disk shape. A valve body support portion 141 and a shaft attachment portion 142 are integrally formed on the disc body 140.
As shown in FIG. 4, the rotary valve body 121 is mounted in the cylinder body 120 via an eccentric shaft 122, and the rotary valve body 121 is provided with a ventilation flow path 30 so as to be openable and closable.

A valve body spherical surface 143 forming a part of the spherical surface is formed on the disc main body 140, and the valve body spherical surface 143 is provided so as to be able to abut as a sealing surface with respect to the conical tapered surface 134 of the seat 21. When the valve is closed, the valve body spherical surface 143 can be sealed with respect to the conical tapered surface 134 in a tangential contact state (also referred to as a line contact state). The valve body spherical surface 143 is provided so that its center is located on the diameter center axis of the cylinder body 120.
Here, the tangential contact (line contact) refers to a sealing state in which the width of the annular seal between the seat 21 and the disc-shaped valve body 23 when the valve is closed is narrower than that of the surface contact.

Although not shown, the valve body spherical surface 143 has a sealing portion formed on the plateau surface in order to prevent sticking to the conical tapered surface 134 when the valve is closed. Further, oil is stored in the dimple portion on the plateau surface, or the valve body spherical surface 143 or the conical tapered surface 134 is used to prevent sticking to the seat 21 when the valve is closed. It may be satin finished.

The valve body spherical surface 143 is not limited to the plateau surface, and may be processed by appropriately roughening the surface thereof. By applying an oil component such as oil to the valve body spherical surface 143, the sealing property is ensured while preventing the valve body spherical surface 143 from sticking to the conical tapered surface 134.

The valve body support portion 141 is provided in a cylindrical shape having a small diameter, and hangs down from the disc body 140 at a position eccentric from the valve body spherical surface 143 of the disc body 140, that is, a position eccentric from the center P1 of the diameter of the cylinder body 120. It is integrally formed so as to do. Following the valve body support portion 141, the shaft attachment portion 142 is formed in a substantially bale-shaped shape. The shaft attachment portion 142 is provided at a double eccentric position eccentric with respect to the center of the disc body 140 and eccentric with respect to the valve body spherical surface 143 of the disc body 140 in the flow path direction on the spherical core side. A through hole 144 into which an eccentric shaft 122, which will be described later, can be inserted is formed in the shaft attachment portion 142.

Further, the shaft-attached portion 142 is formed so as to extend a mounting portion 145 having a predetermined inclination with respect to the horizontal direction from the center of the shaft-attached portion 142 in FIG. 2, and a weight portion is formed on the mounting portion 145. An insertion hole 146 for wearing 123 is provided. Although not shown, the insertion hole 146 is provided with three engaging protrusions at equal intervals in the center along the hole direction.

In FIG. 5, the eccentric shaft 122 is formed in a small diameter shape by, for example, a metal material such as stainless steel, and a locking groove 148 for mounting two retaining rings 147 is formed on the outer periphery thereof at substantially the same interval as the length of the shaft attachment portion 142. Is formed. The eccentric shaft 122 serves as a fulcrum during rotation of the rotary valve body 121, and the rotary valve body 121 is provided with a rotary moment Mc in the valve closing direction in the cylinder body 120 via the eccentric shaft 122. ..

Due to the positional relationship of the shaft attachment portion 142 with respect to the disc body 140, the eccentric axis (fulcrum) 122 is at a position eccentric from the center P1 of the diameter of the cylinder body 120, and the valve body spherical surface 143 of the rotary valve body 121 ( It becomes the center P3 of the valve body support portion 141 located at a position eccentric from the seal center surface). As described above, the eccentric shaft 122, which is the center of rotation of the rotary valve body 121, has a double eccentric structure that is doubly eccentric with respect to the valve body spherical surface 143.

In this case, the eccentricity of the valve body support portion 141 that supports the rotary valve body 121 with respect to the rotary valve body 121, that is, the eccentricity from the center P1 of the diameter of the cylinder body 120 in FIG. 2 to the center P3 of the valve body support portion 141. The distance (eccentricity) D1 / radius r of the rotary valve body 121) is set to about 40%.

The reason for this is described below. For example, in a general butterfly valve body in which water, which is an incompressible fluid, flows in the flow path, even if the eccentricity is set to about 30%, the operation in the valve opening direction is caused by the pressure drop generated on the orifice side. It is known that the moment in the closing direction due to the unbalanced torque generated by the fluid differential pressure between the orifice side and the nozzle side of the valve body, that is, the rotational moment in the valve closing direction due to the fluid flow works. ing.

On the other hand, the fluid flowing through the valve body 100 of the present embodiment is a gas that is a compressible fluid, and the pressure thereof is such that the negative pressure in the drain pipe 3 is eliminated and the trap water of the drainage device is protected. It is ~ 50Pa. As described above, since the gas flowing in the valve body 100 is compressible and is a slight pressure generated by the difference between the low atmospheric pressure and the negative pressure, the large pressure receiving surface side with the valve body support portion 141 as a boundary. The valve closing moment due to the slight pressure applied to the small pressure receiving surface side is likely to fluctuate, and the influence on the valve closing operation of the rotary valve body 121 is also large.
From this, considering the assembly error of the rotary valve body 121 with respect to the valve body 100 and the influence of the shape of the valve body support portion 141, the eccentricity is set to about 40% with a margin, and the third is caused by the fluid flow. The unbalanced torque is reduced so that the rotary valve body 121 can be reliably operated in the opening / closing direction by the first and second unbalanced torques described later.

When the eccentric shaft 122 is made of a metal material, it can be formed into a small diameter while maintaining strength, and it is possible to reduce the ventilation resistance at the time of valve opening and increase the ventilation amount. By mounting the rotary valve body 121 made of a resin material on the eccentric shaft 122, the sliding resistance of the rotary valve body 121 during the rotational operation is reduced.

The weight portion 123 is provided with a predetermined weight due to a substantially cylindrical shape that can be inserted into the insertion hole 146, and an annular groove 149 in which an engaging protrusion can be locked is formed near the center thereof. When the weight portion 123 is formed in a columnar shape as described above, the processing becomes easy and the cost can be suppressed. The weight portion 123 may be other than a columnar shape, and may be formed in a spherical shape, for example. In addition to this, for example, the wall thickness of the side of the disc body 140 that requires the weight portion to be attached is made thicker than the other side sandwiching the eccentric shaft 122 so that the valve body weight is heavier than the other side. It is also possible to omit the weight portion 123 by forming the weight portion 123.

The rotary valve body 121 is rotatably incorporated in the cylinder body 120 via the eccentric shaft 122 described above, so that the rotary valve body 121 is arranged at a position where the valve is opened by the weight of the disc body 140. The valve is closed due to the balance with the weight portion 123 provided on the disc main body 140. At this time, the rotary valve body 121 has a first unbalanced torque that rotates in the valve opening direction via the eccentric shaft 122 at the time of negative pressure in the cylinder body 120 (torque difference due to the pressure receiving area ratio at which valve opening> valve closing). Is generated and the atmosphere can be taken in from the outside.

On the other hand, when the cylinder body 120 is at atmospheric pressure or positive pressure, the second unbalanced torque, which is the torque difference between the mass at which the valve is closed and the position of the center of gravity, which rotates in the valve closing direction via the eccentric shaft 122, is obtained. It is configured to occur and close the valve. Here, at atmospheric pressure, no negative pressure exceeding a preset value (for example, 30 Pa) is generated in the cylinder body 120, and the differential pressure between the primary side and the secondary side of the rotary valve body 121 is high. A state of pressure difference with almost no or almost no need for ventilation. Positive pressure and negative pressure are states in which positive pressure is applied to the cylinder body 120, respectively, and negative pressure above a preset value is applied. The state of being joined. Therefore, the atmospheric pressure is a state including a minute negative pressure, for example, a negative pressure lower than a preset value (30 Pa).

The eccentric distance D1 from the center P1 of the diameter of the cylinder body 120 of the eccentric shaft 122 to the center P3 of the valve body support portion 141, and the center of the seal between the valve body spherical surface 143 and the conical tapered surface 134 (center of the valve body seal surface). By changing the eccentric distance D2 from P2 to the center P3 of the valve body support portion 141, the eccentricity is doubled from the seal position of the rotary valve body 121 (the contact position between the valve body spherical surface 143 and the conical tapered surface 134). The eccentricity can be set arbitrarily, and by setting these double eccentricities in advance, the opening / closing operation / sealing function due to the unbalanced torque in the valve opening direction and the valve closing direction can be adjusted.

The body 111 is formed in a substantially tubular shape by a resin material such as ABS resin, more specifically, a transparent or translucent resin material, and a valve unit 110 is provided so as to be interpolated from above. The drainage pipe insertion port 63 formed in the lower part of the body 111 is integrated with the cylinder body 120. As a result, the insertion state of the extension ventilation pipe 4 can be easily visually recognized from the outside of the drainage pipe insertion port 63.

An enlarged diameter annular step portion 60 is formed on the upper portion of the body 111, and a bayonet type connection recess 61 for fixing the cap 112 is formed above the annular step portion 60. An annular edge portion 62 is formed on the inner circumference of the body 111 at a substantially intermediate position in the height direction, and the lower end of the valve unit 110 inserted from above the body 111 is provided so as to be in contact with the annular edge portion 62. The body 111 is positioned in the height direction.

The drainage pipe insertion port 63 for connecting the extension ventilation pipe 4 and the external drainage pipe is provided in the lower part of the body 111, and the drainage pipe insertion port 63 is a valve unit on the upper part of the body 111 by the annular edge portion 62. It is separated from the 110 insertion side. The extension ventilation pipe 4 and the external drainage pipe are inserted from the lower part of the body 111, and at this time, the tip of these pipes abuts on the annular edge portion 62, so that the body 111 is positioned and fixed to the pipe in this state. Be glued.

By attaching the cylinder body 120 to the body 111 in this way, the drainage pipe insertion port 63 is provided integrally with the body 111. As described above, since the drainage pipe insertion port 63 is formed to be transparent or translucent, the state of adhesion to the extension ventilation pipe 4 and the external drainage pipe can be visually recognized from the outside.

The cap 112 is formed of a resin material such as ABS resin, has an annular portion 150 at the upper portion and a connecting portion 151 with the body 111 at the lower portion, and a columnar portion 152 is provided between the annular portion 150 and the connecting portion 151. Are spread over four places at equal intervals, and a ventilation path 153 is formed between these columnar portions 152. In this way, by providing the ventilation passage 153 between the four columnar portions 152, the ventilation area of the ventilation passage 153 becomes large and a large amount of ventilation is secured.

The connection portion 151 is formed to have an outer diameter that can be inserted from the upper part of the body 111, and an outer peripheral convex piece 72 that can be connected to a bayonet is formed on the outer periphery of the connection portion 151 in the connection recess 61 formed in the body 111. Will be done. The inner diameter of the connecting portion 151 is provided so that the cylinder body 120 can be fitted and has substantially the same diameter as the cylinder inserted portion of the body 111.

A notch groove 154 is formed on the upper outer peripheral surface of the columnar portion 152, and the outer peripheral side of the bottom surface of the annular portion 150 becomes an annular shape through the notch groove 154, and this annular portion is the engaging portion 155 with the cover 113. Will be. On the other hand, on the inner diameter side of the connecting portion 151, an inner peripheral flange portion 156 for holding the upper surface of the sheet 21 is formed so as to project toward the inner diameter side, and further, on the inner diameter portion of the inner peripheral flange portion 156 on the sheet contact side. , An annular recess 157 may be formed.

At the intermediate position of the cap 112, a concave portion 158 that can be engaged with the convex portion 133 formed near the center of the outer periphery of the cylinder body 120 is intermittently formed at a position corresponding to the convex portion 133.

The cover 113 is provided in a substantially circular lid shape, and claws 160 that can be engaged with the engaging portion 155 of the cap 112 are formed at three positions on the bottom surface of the cover 113. The cover 113 is detachably provided on the upper part of the cap 112 via the claw portion 160, and is rotatable with respect to the cap 112 after attachment.

When assembling the valve unit 110, first, the weight portion 123 is inserted into the insertion hole 146 of the mounting portion 145 of the rotary valve body 121. At this time, by inserting the weight portion 123 until the engaging protrusion is locked in the annular groove 149, the weight portion 123 can be attached to the predetermined position of the insertion hole 146 to prevent the weight portion 123 from falling off.

Subsequently, the rotary valve body 121 is arranged along the upper surface of the cylinder body 120 so as to be along the disk body 140, and the tip of the eccentric shaft 122 is inserted into the cylinder body 120 from the outside of one mounting hole 130 of the rotary valve body 121. Then, after inserting the tip into the through hole 144 of the rotary valve body 121, the tip is inserted into the other mounting hole 130 from the inside of the cylinder body 120. As a result, the rotary valve body 121 is attached to the cylinder body 120 by the eccentric shaft 122 via the shaft attachment portion 142, and is in a state of being rotatable in the cylinder body 120. In this state, the axle attachment portion 142 is positioned between the two locking grooves 148 and 148, and the retaining ring 147 is locked in each locking groove 148, whereby the axle attachment portion 142 is centered on the eccentric shaft 122. Position to.

When the rotary valve body 121 is assembled to the cylinder body 120, there is a gap (play) between the rotary valve body 121 (shaft attachment portion 142) and the eccentric shaft 122 for the rotary valve body 121 to rotate. You will need it. Therefore, when the rotary valve body 121 rotates in the valve closing direction, the mounting position may shift due to this gap, and the valve body spherical surface 143 may not be able to properly adhere to the conical tapered surface 134. On the other hand, if the rotary valve body 121 is held in a state where the valve body spherical surface 143 is brought close to the conical tapered surface 134 and the valve body spherical surface 143 is incorporated while being aligned with the conical tapered surface 134, the valve body spherical surface 143 is surely incorporated. The rotary valve body 121 can be closely sealed to the conical tapered surface 134.

Next, the sheet 21 is placed from the cylinder body 120 storage direction of the cap 112, and the cylinder body 120 is inserted and mounted. At this time, the convex portion 133 engages with the concave portion 158 so that the cylinder main body 120 can be incorporated in a predetermined position of the cap 112, and the valve unit 110 while mounting the sheet 21 between the cylinder main body 120 and the cap 112. Can be integrated as. The cover 113 may be attached to the cylinder body 120 after the cap 112 is attached, or may be attached to the cap 112 in advance.

The sheet 21 is sandwiched between the cap 112 and the cylinder body 120 while its outer circumference abuts on the inner circumference of the cap 112 and is positioned in the radial direction. After mounting the seat 21, a space T may be provided between the annular recess 157 and the inner diameter side of the seat 21, and the space T may ensure the flexibility of the conical tapered surface 134.

Finally, the valve unit 110 is attached to the body 111. In this case, the connecting portion 151 of the valve unit 110 is charged from the body opening side, and the outer peripheral convex piece 72 formed on the cap 112 and the connecting concave portion 61 of the body 111 are attached by bayonet connection. After these integrations, the cap 112 (valve unit 110) is prevented from naturally falling off from the body 111, and the cap 112 and the body 111 are sealed by an O-ring 161 provided on the lower outer periphery of the cap 112. Seal to prevent leakage from between these. Since the cap 112 is removable from the body 111, it can be freely removed from the body 111 for maintenance and the like.

In FIGS. 1 to 3, when the valve main body 1 is attached to the system main body 2, the extension vent pipe 4 coated with the adhesive is connected to the drainage pipe insertion port 63 at the lower part of the body 111 so as to be inserted. To. At this time, since the body 111 is formed to be transparent or translucent, the inserted state of the extension ventilation pipe 4 and the applied state of the adhesive can be visually recognized from the outside through the drain pipe insertion port 63.

In the above embodiment, the rotary valve body 121 is attached so that the eccentric shaft 122 is on the drain pipe 3 (extended ventilation pipe 4) side, but the eccentric shaft 122 is attached so as to be on the atmosphere side. You may. When the eccentric shaft 122 is provided on the drain pipe 3 side, the aesthetic appearance from the upper side can be improved, while when the eccentric shaft 122 is provided on the atmospheric side, the drainage of the eccentric shaft 122 comes into contact with steam or foreign matter. It can be avoided and the durability can be improved.

Further, the valve body may be provided in a structure that can be arranged sideways. In this case, by connecting the piping to the primary and secondary sides of the valve body, it can be used as a so-called in-line type.

Next, the operation of the rotary valve mechanism in the present invention, the ventilation valve using the rotary valve mechanism, and the drainage pipe system in the above embodiment will be described.
As described above, the rotary valve mechanism in the present invention can be used, for example, as an internal mechanism of the valve body 100. At this time, the rotary valve body 121 can swing via the eccentric shaft 122 as a fulcrum, and the rotary moment Mo that rotates in the valve opening direction and the valve closing direction rotate in response to the pressure fluctuation in the cylinder body 120. The rotation moment Mc works, and the valve body 100 exerts the vent valve function by these.

In this case, in FIG. 2, when the rotational moment acting on the entire rotary valve body 121 about the eccentric axis 122 is in the counterclockwise direction (in the negative rotation direction), the rotary valve body 121 is in the valve opening direction. When it rotates and is in the clockwise direction (the positive rotation direction), the rotary valve body 121 rotates in the valve closing direction.

As a result, at the time of negative pressure in the cylinder body 120, a rotational moment in which the rotary valve body 121 rotates in the negative rotation direction acts based on the differential pressure generated by the pressure difference between the inside of the pipe of the rotary valve body 121 and the atmosphere side. This rotational moment generates an unbalanced torque that rotates in the valve opening direction. On the other hand, at atmospheric pressure or positive pressure in the cylinder body 120, a rotational moment is exerted in which the rotary valve body 121 rotates in the positive rotational direction due to the equilibrium with the weight portion 123, and this rotational moment causes the rotary valve body to rotate in the valve closing direction. Generates balance torque.

As described above, the unbalanced torque of the valve body 100 is a rotational force generated by a rotational moment in the positive and negative rotational directions acting on the rotary valve body 121. From this, when the differential pressure between the inside of the pipe of the rotary valve body 121 and the atmosphere side is eliminated, that is, when the pressure difference between the inside and outside of the rotary valve body 121 is 0 (atmospheric pressure), and the rotation including the positive pressure. When a rotational moment in the positive rotational direction is applied to the valve body 121, the rotary valve body 121 rotates in the valve closing direction.

Since the valve body support portion 141 is formed at the eccentric position, the rotary valve body 121 tends to rotate in the valve opening direction by its own weight due to the weight difference with the valve body support portion 141 as a boundary. However, by providing the weight portion 123 that applies a rotational force in the valve closing direction, the rotary valve body 121 that normally tries to open the valve by its own weight is maintained in the valve closed state due to the balance with the weight portion 123. ..

In the present embodiment, the peak of the valve closing force of the rotary valve body 121 is set to be 25% of the valve opening position, so that the rotary valve body 121 has a slightly opening position near the fully closed position, for example. When the valve opening is 5%, the valve closing force at this valve opening is smaller than the valve closing force at the valve opening of 25%. The valve opening force, that is, the rotational moment Mo that rotates in the valve opening direction also changes with the fluctuation of the pressure inside the pipe, and the rotary valve body 121 operates while the valve closing direction rotational moment and the valve opening direction rotational moment are balanced, although the rotary valve body 121 swings. However, in the slight opening range, it is possible to prevent the seat 21 from being shockedly seated and to prevent the chattering phenomenon.

On the other hand, even when the peak of the valve closing force of the rotary valve body 121 is set to be the valve opening degree of 50%, the rotary valve body 121 has the valve opening degree as in the case of the valve opening degree of 25%. When the opening position is smaller than 50%, the valve closing force becomes smaller than the valve closing force at the valve opening of 50%, and the same function is exhibited.

If the peak of the valve closing force of the rotary valve body 121 is set to be less than the valve opening degree of 5%, the difference in the valve closing force from the valve closed state becomes small, and when the negative pressure is relaxed from this state. In response to the relaxation, the rotary valve body 121 tends to reach a valve closed state, and there is a possibility that the rotary valve body 121 cannot immediately sit on the seat 21 and relax a minute negative pressure.

On the other hand, if the peak of the valve closing force of the rotary valve body 121 is set to exceed 50% of the valve opening, more than half of the state is maintained in the opening range where the valve opening is large when negative pressure is generated. Therefore, it takes time to reach the valve closed state, and the risk of odor leakage from the extension ventilation pipe 4 and the drainage pipe 3 increases.

Here, FIG. 6 shows a schematic diagram of the double eccentric valve main body 100 according to the present invention. FIG. 7 shows a schematic diagram of a ventilation device having various structures according to the prior art for comparison with the valve body 100, and the inner diameter φd of the ventilation flow path 30 of these ventilation devices is the valve body 100 of FIG. It has substantially the same dimensions as the inner diameter φd of, and has substantially the same flow area.

In the ventilation device 170 shown in FIG. 7A, an annular valve body 171 is provided in the housing 172 so as to be able to move up and down, and normally, the valve body 171 is seated on the valve seat 173 by its own weight and is in a valve closed state. .. When a negative pressure is generated, the valve body 171 is lifted from the valve seat 173 to be in a valve open state, so that the negative pressure is reduced. A cap 174 is provided above the valve body 171 integrally with the housing 172.

The ventilation device 180 shown in FIG. 7 (b) is a self-weight type ventilation device of FIG. 7 (a) in which a compression spring 181 is added between the valve body 171 and the cap 174, and the valve is closed. In the direction, in addition to the weight of the valve body 171, the elastic force of the compression spring 181 also acts.

The ventilation device 190 shown in FIG. 7C has a structure in which the valve body 191 is cantilevered and supported via the shaft attachment portion 192, and the valve body 191 is rotatably mounted in the housing 193 by a so-called swing check type. ing.

In FIG. 8, the valve closing force-valve opening characteristic of the valve body itself is shown in a graph for the valve body 100 of FIG. 6 and the ventilation devices 170, 180, 190 of FIG. 7, respectively. The left vertical axis shows the valve closing force.

The “valve opening” on the horizontal axis of the graph is the lift amount (fully open lift amount) of the valve body 171 for the ventilation devices 170 and 180 by the self-weight type valve body 171 of FIGS. 7 (a) and 7 (b). The ratio to [%]) is shown. On the other hand, for the valve body 100 in which the rotary valve body 121 in FIG. 6 swings around the eccentric shaft 122 and the swing check type ventilation device 190 in FIG. 7 (c), the rotary valve body 121 and the valve body 191 are respectively. The amount of rotation angle (ratio to fully open opening [%]) is shown.

The “valve closing force” on the vertical axis of the graph is the force acting in the valve closing direction of the valve body 171 (self-weight of the valve body 171) for the ventilation devices 170 and 180 in FIGS. 7 (a) and 7 (b). And the total elastic force of the compression spring 181). On the other hand, with respect to the valve body 100 of FIG. 6 and the ventilation device 190 of FIG. 7C, the magnitudes of the rotational moments when the rotary valve body 121 and the valve body 191 rotate in the closed direction are shown.

In FIG. 8, with respect to the valve body 100 of FIG. 6 according to the present invention, the characteristic that the peak of the valve closing force of the rotary valve body 121 is set to the valve opening degree θ = 30 ° is shown in the graph a, and the valve opening degree θ is shown. The characteristic set to = 20 ° is shown in graph b.
Further, the valve closing force of the valve body 100 of the present invention and the ventilation devices 170, 180, 190 shown in FIG. 7 in the fully closed state is such that the valve is opened at atmospheric pressure with respect to the ventilation pipe in which the negative pressure is eliminated. However, it is set to a value that can ensure the valve seat sealability.
For comparison of each characteristic, the value of the valve closing force in the fully closed state of the graphs b to e is set to Ps which is the same value.

As shown in the graph, in the case of the valve body 100 of the present invention, the peak (Pbp) of the valve closing force of the rotary valve body 121 is set to the valve opening degree θ = 20 ° of a and the valve opening degree θ = 30 ° of b. By setting each, in any case, the peak of the valve closing force (Pbp) at these intermediate openings becomes larger than the valve closing force (rotational moment) in the valve closed state. In this way, with the valve closing force Ps in the fully closed state as a reference, the slope represented by the equation of "change amount of valve closing force" / "change amount of valve opening" is positive larger than 0 in each graph. By setting the value, the peak of the valve closing force is surely set at the position of the intermediate opening degree, and the peak of the valve closing force can be set at an arbitrary angle from the fully closed valve opening to the fully opened valve opening. This effect can be obtained, for example, by inclining the weight portion 123 toward the ventilation pipe 4 in the horizontal direction parallel to the seat (valve seat) 21 via the mounting portion 145, as will be described later. ..

In this case, the valve closing force Pas in the fully closed state in the graph a is set lower than the valve closing force Ps in the fully closed state in the graph b. As a result, in the graph a, the pressing force between the seat 21 and the rotary valve body 121 in the valve closed state can be reduced, the valve seat sealing property can be maintained for a long period of time, and the valve opening operation when a negative pressure is generated can be maintained. The reaction can be improved.

The valve seat sealing property can be improved as necessary by changing the flexibility and adhesion of the seat 21 such as the material of the seat 21 and the formation of a gap on the back surface of the sealing surface. When the valve seat sealing property is set low, the pressure response is improved and the valve opening operation becomes easier even when the negative pressure is a minute pressure, and the effect of reducing the noise due to the drainage noise in the ventilation pipe due to the negative pressure is also exhibited.

In graph b, the valve opening operation due to negative pressure is described.
In the valve body 100 shown in the graph b, when a negative pressure is generated in the pipe and a force acting in the valve opening direction larger than Ps, that is, a valve opening force is generated, the rotary valve body 121 opens the valve from the closed state. Since the rotary valve body 121 has a characteristic that the valve closing force increases in a substantially cosine curve as the valve opening angle increases from the valve closed state (0 °), it reaches the peak of the valve closing force (Pbp). Between them, the "valve opening force due to the negative pressure in the pipe" and the "valve closing force of the valve body" are positioned at an opening degree that is balanced.

In other words, the "rotational moment in the valve opening direction of the rotary valve body 121" due to the assumed normal negative pressure in the pipe causes the rotary valve body 121 to "fully close to the peak of the valve closing force (Pbp)". The rotational moment in the closing direction of the rotary valve body 121 by the weight portion 123 of FIG. 2 is set so that the opening degree is balanced within the range of the opening degree. In this region α (Ps <P <Pbp), the rotary valve body 121 is located near a position where the rotational moment in the valve opening direction and the rotational moment in the valve closing direction are balanced even if a slight pressure fluctuation occurs in the pipe. Since it swings according to the valve opening degree of the above, the chattering phenomenon does not occur without being seated on the valve seat (seat) 21.

In the region where a large negative pressure is generated in the pipe and exceeds the normal negative pressure and exceeds the peak of the valve closing force (Pbp), the valve closing force of the rotary valve body 121 conversely reaches Pbo in a substantially cosine curve. Since it is reduced, the difference from the negative pressure in the pipe becomes large, the valve opening becomes quick and large, and the maximum ventilation is performed by increasing the total area of the opening (ventilation flow path 30) with the valve opening. We will quickly relieve the negative pressure in the pipe.

Next, the valve closing operation accompanying the decrease in negative pressure in each of the above vent valves will be described.
In the valve body 100 (graph b), the rotary valve body 121 secures the maximum air flow rate in the state where the valve is opened at the maximum angle (80 ° in this embodiment) due to the large negative pressure in the pipe. As the valve opening increases, the rotational moment of the rotary valve body 121 in the closing direction, that is, the minimum valve closing force (Pbo) becomes, but the force in the valve opening direction becomes extremely small due to the relaxation of the negative pressure, so that the rotary valve body 121 rotates. The valve closing operation starts when the rotational moment in the closing direction of the valve body 121 exceeds the rotational moment in the valve opening direction that is relaxed and reduced by ventilation. At the start of this valve closing operation, since the rotational moment of the rotary valve body 121 in the closing direction is small, the rotary valve body 121 starts to operate slowly and operates in the valve closing direction at an accelerated rate until the peak of the valve closing force is reached.

Here, in the rotary valve body 121, in the region where the valve closing force P is a value of Pbp> P> Pbo, that is, in the region of a large valve opening degree, the “change amount of the valve closing force” / “change in the valve opening degree”. By setting the inclination expressed by the equation of "quantity" to a negative value, the valve opening angle is maintained at the position where the rotational moment in the valve closing direction is balanced with the rotational moment in the valve opening direction with respect to the pressure fluctuation generated in the pipe. ..

Then, when the negative pressure is continuously relaxed, that is, when the negative pressure continues to decrease, the rotary valve body 121 is coupled with a rotational moment that increases in the closing direction in order to balance with the decreasing rotational moment in the valve opening direction. , It moves greatly in the valve closing direction toward the peak of the valve closing force.

After that, after the rotary valve body 121 operating in the valve closing direction reaches the peak of the valve closing force (Pbp), the rotational moment in the valve closing direction and the rotational moment in the valve opening direction are balanced, and then in the fully closed direction. Continues to operate (approaches the valve seat 21), and the rotational moment in the valve closing direction of the rotary valve body 121 acts in the direction of reducing the valve closing operation of the rotary valve body 121 (direction that hinders the valve closing operation) and closes. The operation slows down and balances. Therefore, the chattering phenomenon can be prevented or alleviated without the rotary valve body 121 and the valve seat 21 coming into contact with each other.

As described above, since the valve body 100 has a valve closing force characteristic having a substantially cosine curve shape such that the valve closing force peaks at the intermediate opening degree from fully closed to fully opened, the pipe is piped after the valve is opened. Even if the negative pressure fluctuation occurs, the rotary valve body 121 swings within the range from 0 to the peak of the valve closing force (Pbp) (intermediate opening: 5 ° to 50 °), and accompanies the negative pressure fluctuation. The chattering phenomenon can be prevented or mitigated.

In addition, when the rotary valve body 121 is fully opened in response to a large sudden negative pressure generated in the pipe, the negative pressure is alleviated by securing the air volume and the valve is closed, and then the pressure fluctuations cause hypersensitivity. If the valve is not closed in response to, and if negative pressure is continuously generated and the valve closing operation continues to the α region, the valve closing operation is decelerated at the intermediate opening (5 ° to 50 °). Since the valve closing force and the valve opening force are balanced, chattering can be suppressed.
In this embodiment, the valve closing force characteristic is substantially a cosine curve, but for example, the number, shape, and arrangement of the weight portions 123 may be freely changed to change the characteristics of the angle before and after Pbp.

On the other hand, in the case of the self-weight type ventilation device 170 of FIG. 7A, the valve opening force is constant from the fully closed state to the fully opened state as shown in the graph c. Therefore, when a negative pressure exceeding the valve closing force is generated in the pipe, the valve opening force is always larger than the valve closing force Ps of the valve body 171. Therefore, it exhibits unstable behavior due to pressure fluctuation in an attempt to balance with the amount of airflow depending on the degree of valve opening. When drained from a residential sewage pipe, a sudden negative pressure is generated, the valve body 171 operates in the opening direction, and then when a large swing back occurs due to the elimination of the negative pressure, the valve closing force becomes relatively large. The valve body 171 is in a fully closed state, the valve opening cannot be maintained, and chattering is likely to occur in response to fluctuations in negative pressure.

Further, in the case of the ventilation device 180 of FIG. 7B, in addition to the own weight of the valve body 171, the elastic force of the compression spring 181 also acts in the valve closing direction, so that the valve opening degree increases as shown in graph d. The valve closing force increases proportionally with this. Therefore, when the negative pressure in the intermediate opening or the fully open state, that is, the negative pressure in the pipe is relaxed in the region α (Ps <P <Pbp) and the region β (Pbp <P <Pdo), the compression spring 181 The elastic force is released, and the valve body 170 vigorously closes the valve. Therefore, the valve body 171 is difficult to follow the fluctuation of the negative pressure, and the valve opening cannot be maintained in the slight opening region, so that chattering is likely to occur in response to the fluctuation of the negative pressure.

In the case of the swing check type (cantilever type) ventilation device 190 of FIG. 7 (c), as shown in graph e, the valve closing force (rotational moment of the valve body 191) increases as the valve opening increases. It becomes smaller, and the slope represented by the equation of "change amount of valve closing force" / "change amount of valve opening degree" becomes a negative value smaller than 0. Therefore, the valve body 191 has a structure in which it is difficult to return to the fully closed state even when the negative pressure is relaxed in the intermediate opening or the fully open state.

On the other hand, since the valve closing force of the ventilation device 190 is the largest at the valve closing position, it is difficult for the valve body 191 of the ventilation device 190 to follow the fluctuation of the negative pressure as a whole, and the valve opening is maintained in the slight opening region. Therefore, chattering is likely to occur in response to fluctuations in negative pressure.
In this ventilation device 190, the valve closing force becomes substantially 0 at around 90 degrees structurally, so that it becomes difficult for the valve body 191 to return to the valve closed state. Therefore, it is necessary to regulate the valve opening that is fully opened in advance, which also leads to a decrease in the amount of airflow when the valve is opened.

Here, in the valve body 100 of FIG. 6, since the ventilation flow path 30 has a straight shape and does not require an intake flow path on the enlarged diameter side of the inner diameter φd of the ventilation flow path 30, for example. Negative pressure can be eliminated while keeping the diameter of the external pipe (vent pipe) equal to or smaller than that of the external pipe (vent pipe) such as the extension ventilation pipe 4 of FIG. Further, at the time of ventilation, the rotary valve body 121 rotates until the direction is substantially parallel to the flow direction of the ventilation flow path 30, so that the ventilation resistance can be minimized and a sufficient ventilation amount can be secured.

On the other hand, in the case of the ventilation devices 170 and 180 of FIGS. 7 (a) and 7 (b), when the inner diameter φd of the same ventilation flow path 30 as the valve body 100 of FIG. 6 is secured, the external pipe (vent pipe) is used. Also, the intake flow path 175 is required on the diameter expansion (outer diameter) side, and the entire diameter is expanded to the size of the outer diameter φD of the intake flow path 175. For this reason, a space for installing the ventilation devices 170 and 180 is required more than the piping space of the ventilation pipe.

Also in the case of the ventilation device 190 of FIG. 7C, the cantilever bearing portion 192 is located outside the outer diameter φD of the intake flow path 195 on the outer diameter side of the inner diameter φd of the ventilation flow path 30. As in the case of FIGS. 7 (a) and 7 (b), the whole is enlarged in the outer diameter direction, making it difficult to make it compact, and a large installation space is required.

FIG. 9A shows another graph showing the relationship between the valve opening degree and the valve closing force. In the figure, the characteristic that the peak of the valve closing force of the rotary valve body 121 is set to the valve opening θ = 40 ° (valve opening 50%) is shown in the graph a, and the valve opening θ = 5 ° (valve opening). The characteristics set to 5%) are shown in graph g. The characteristics of each state shown in graphs b to e other than these are as described in FIG. 8 above.

As shown in Graph a, when the peak of the valve closing force of the rotary valve body 121 is set to the valve opening of 50%, the ratio from the fully closed to the valve opening of 50% and the valve at the peak time are set. The ratio from the opening of 50% to the time of full opening is the same. From this state, if the peak of the valve closing force of the rotary valve body 121 is set to exceed the valve opening of 50%, the ratio of the valve being maintained in the valve open state when a negative pressure is generated increases, and the valve open state is changed. It will be longer than necessary. Therefore, there is a high risk of odor leakage from the drainage pipe 3 and the extension ventilation pipe 4 connected to the valve body 100.

As shown in graph g, when the peak of the valve closing force of the rotary valve body 121 is set to be less than the valve opening degree of 5%, the operation of the rotary valve body 121 from the valve body opening at the peak to the valve closed state is performed. The range becomes narrower. In addition to this, the difference between the magnitude of the valve closing force at the peak when the valve is closed and the magnitude of the valve closing force at the time of fully closing is reduced. As a result, when the negative pressure is relaxed, the rotary valve body 121 tends to reach a valve closed state according to the relaxation, and there is a possibility that the minute negative pressure cannot be relaxed.

Subsequently, the valve closing force-valve opening characteristic shown in the graph of FIG. 9A will be described based on the relationship with the negative pressure fluctuation. FIG. 9B shows the change in the magnitude of the negative pressure from the generation of the negative pressure of the valve body 100 to the time when the negative pressure is eliminated in the above embodiment, and the negative pressure generated when the negative pressure is eliminated by the valve body 100. It represents an example of the change in. The alternate long and short dash line in FIG. 9 (b) represents the magnitude of the valve closing force in the fully closed state with respect to the magnitude of the negative pressure, and corresponds to Ps (Pas) in FIG. 9 (a).

In FIG. 9B, when the pressure inside the drain pipe 3 changes from the atmospheric pressure (1) to a negative pressure and exceeds a predetermined negative pressure (2), that is, the valve closing force in the fully closed state, the rotary valve body 121 valves. The operation in the opening direction is started. At this time, the rotary valve body 121 reaches the maximum negative pressure (3) generated in the drain pipe 3 by opening the valve closing force to be equal to or larger than the valve opening degree showing the peak value (Pbp in FIG. 9A). On the other hand, it is designed to provide sufficient ventilation.

When the negative pressure is relaxed by this ventilation and the negative pressure drops to the state of (4), the rotary valve body 121 operates in the closing direction due to the decrease of the negative pressure. At this time, if the negative pressure in the drain pipe 3 cannot be alleviated (5), the rotary valve body 121 does not close until the valve opening at which the valve closing force reaches the peak value, and the rotary valve body 121 operates until it is fully closed. It never reaches. When the rotary valve body 121 is slightly closed, the amount of airflow is reduced, so that the negative pressure rises to the state of (5). Along with this, the rotary valve body 121 opens again.

In this way, the rotary valve body 121 operates in the valve opening operation in response to the negative pressure, and when the negative pressure decreases, the rotary valve body 121 operates in the valve closing direction, and the rotary valve body 121 repeatedly operates in the valve closing direction in response to the negative pressure. , It is designed to relieve negative pressure. As a result, even if the magnitude of the negative pressure changes from the state of (5) to the states of (6), (7), and (8), the opening degree at which the rotary valve body 121 exhibits the above peak value is kept below. Otherwise, by repeating swinging (opening / closing operation) without reaching the valve closed state, chattering does not occur from the generation of the negative pressure to the relaxation state of the negative pressure.

The rotary valve body 121 relaxes the negative pressure to the states (9) and (10) while exerting the so-called braking function, and when the negative pressure is relaxed, the rotary valve body 121 falls below the opening degree at which the above peak value is exhibited. When the magnitude of the negative pressure falls below the predetermined negative pressure state Ps, (12), the rotary valve body 121 is fully closed.
As a result, the inside of the drain pipe 3 returns to the state of atmospheric pressure (1), and the fully closed state is maintained in this state of atmospheric pressure.

As a comparison with the valve body 100 of the present embodiment, even in the case of the ventilation device 170 having the self-weight type valve body 171 of FIG. 7 (a), in the graph shown in FIG. 9 (b), the inside of the pipe has an atmospheric pressure (1). ), And when the predetermined negative pressure (2) is exceeded, the valve body 171 operates in the opening direction.
In this case, as shown in the graph c of FIG. 9A, the peak of the valve closing force at the intermediate opening degree of the valve body 171 is not set, and the valve closing force is constant. Therefore, the negative pressure shown in FIGS. 9 (b) (2), (3), (5), (6), (7), (8), (10), and (11) is alleviated. In the state, the valve body 171 easily returns to the valve closed state. At this time, if the negative pressure in the pipe is larger than the predetermined negative pressure (2), the valve body 171 will open again. As a result, chattering is likely to occur by repeating the valve opening / closing operation in each of these relaxation states.

In the case of the ventilation device 180 of FIG. 7B, the compression spring 181 is added to the ventilation device 170 of FIG. 7A, and the valve body 171 is urged in the valve closing direction by the compression spring 181. ing. Therefore, as shown in the graph d of FIG. 9 (a), the peak of the valve closing force at the intermediate opening degree of the valve body 171 is not set, and (3), (5), (5) of FIG. 9 (b). At the stage of the relaxation state of the negative pressure as in 6), (7) and (11), the valve body 171 tends to vigorously reach the fully closed state by the reaction force of the compression spring 181. As a result, as in the case of the ventilation device 170 of FIG. 7A, chattering is likely to occur by repeating the valve opening / closing operation every time the negative pressure is relaxed.

In the case of the swing check type ventilation device 190 of FIG. 7 (c), as shown in the graph e of FIG. 9 (a), the peak of the valve closing force is set to the fully closed position, and the valve closing force is fully opened. It is getting stronger from the state to the fully closed state.
Therefore, the generation of the negative pressure in FIG. 9B makes it easier for the valve body 191 to open, and when the inside of the pipe exceeds the predetermined negative pressure (2), the valve opening operation is immediately started.
In the open state of the valve body 191 if it is in the fully open position, for example, the negative pressure fluctuates from (3) to (4) and may operate from the fully open state to the fully closed state, and chattering is likely to occur. Become.

In the valve body 100 of the present embodiment, in addition to the above-mentioned advantages, the rotary valve body 121 has a rotational moment in the opening / closing direction, and the rotary valve body 121 operates by opening / closing with a fluid pressure difference using this rotational moment. Therefore, the responsiveness to negative pressure can be adjusted by setting the mass of the weight portion 123 and the like. When a negative pressure is generated, the rotary valve body 121 has a structure that rotates around the eccentric shaft 122, so that the rotary valve body 121 is affected by a slight pressure fluctuation and has excellent responsiveness to perform a valve opening operation. ..

As described above, at the time of valve opening, the rotary moment Mo in the valve opening direction acts until the negative pressure is completely eliminated to maintain the open state of the rotary valve body 121, and the rotary valve body 121 has a fluid pressure difference. Prevents rotation in the valve closing direction. Therefore, the chattering phenomenon can be prevented without the valve body spherical surface 143 repeatedly coming into contact with the conical tapered surface 134. This chattering prevention function prevents the generation of noise during drainage and enables opening and closing operations while maintaining quietness.

Further, by providing the fulcrum by the eccentric shaft 122 having a double eccentric structure, the sealing property when the valve is closed can be exhibited while minimizing the sliding range between the conical tapered surface 134 and the valve body spherical surface 143, and the rotation can be achieved. The opening and closing operation of the valve body 121 also becomes smooth.

Although not shown, the distance from the disc body 140 to the eccentric shaft 122, the distance from the eccentric shaft 122 to the weight portion 123 (mounting portion 145), the tilt angle of the mounting portion 145, the weight of the weight portion 123, etc. are preset. This makes it possible to provide a valve body 100 that can obtain a rotational moment of a predetermined magnitude when the valve is opened and closed, and can reliably eliminate even a minute negative pressure.

In particular, in the present embodiment, when the weight portion 123 is in the horizontal position with respect to the eccentric axis 122, a force in the direction perpendicular to the eccentric axis 122 (the tangential direction with respect to the outer periphery of the eccentric axis 122) acts on the weight. The rotational moment by the portion 123 becomes maximum and the valve closing force peaks. In this way, by adjusting the angle of inclination of the mounting portion 145 in advance, the peak of the valve closing force of the rotary valve body can be set to an arbitrary opening degree between the valve opening degree fully closed and the valve opening degree fully opened.

When the peak of the valve closing force of the rotary valve body 121 is set to be 25% of the valve opening degree as in the present embodiment, the angle of the mounting portion 145 is approximately 30 with respect to the horizontal direction as shown in FIG. It may be provided with an inclination of °. On the other hand, when the peak of the valve closing force of the rotary valve body 121 is set to be 50% of the valve opening degree, the angle of the mounting portion 145 may be provided with an inclination of approximately 50 ° with respect to the horizontal direction.

As a result, when the valve is closed, the valve body spherical surface 143 seals with the conical tapered surface 134 in a tangential contact state, thereby exhibiting high sealing performance, and further, this tangential contact with the valve body spherical surface 143 and the conical tapered surface 134. Is inclined toward the flow path side, so that dew condensation can be prevented when the valve is closed.

In FIG. 1, the valve main body 100 is attached to the tip of the extension ventilation pipe 4 to provide the system main body 2, so that the drainage horizontal branch pipe 3b and the drainage stand connected to the drainage device 8 in the system main body 2 are provided. When a negative pressure is generated inside the pipe 3a, this negative pressure can be released from the valve body 100 to the atmosphere (outdoor) to be eliminated.

In this case, as described above, since the valve body 100 can be made compact while ensuring the air flow amount, it can be installed in the piping space S where the depth dimension W between the outer wall 5 and the inner wall 6 is narrow. As a result, the valve body 100 is connected to the drain pipe 3 in the piping space S while ensuring a wide living space in a building such as an individual house or an apartment house, and the valve main body 100 is connected in the drain pipe 3 while preventing the chattering phenomenon. Negative pressure can be eliminated.
Further, the size of the inspection port 6a can be reduced by making the valve body 100 compact, and maintenance and inspection of the valve body 100 can be easily performed through the inspection port 6a.

At that time, if the air permeability of the valve body 100 is deteriorated due to aged deterioration or the like, this valve is in a state where the valve body 100 is connected to the extension ventilation pipe 4 or in a state where the valve body 100 is removed. The cap 112 is removed from the body 111 of the main body 100, and then the valve unit 110 inserted in the body 111 is integrally taken out as a cartridge. This makes it possible to easily perform maintenance on the valve body 100, clean the valve mechanism portion and the inside of the extension vent pipe 4, and clean or replace the entire valve unit 110 or the internal parts individually. As a result, the vent valve function can be restored and the chattering phenomenon can be suppressed.

10 and 11 show a second embodiment in which the rotary valve mechanism of the present invention is used as a vent valve. In addition, after this embodiment, the same part as the said embodiment is represented by the same reference numeral, and the description thereof will be omitted.
This vent valve (valve body 200) is used as an in-line check valve in which an external pipe 201 is connected to the primary side and the secondary side and is connected to a lateral flow path. In the figure, the left side of the rotary valve body 121 shows the primary side, the right side shows the secondary side, FIG. 10 shows the valve closed state, and FIG. 11 shows a fluid (for example, air) flowing from the primary side to open the valve. It shows the state of being in the (fully open) state.

In this embodiment, the mounting hole 204 of the mounting portion 203 for mounting the weight portion 123 of the rotary valve body 202 is formed so as to extend from the eccentric shaft 122 in a direction substantially perpendicular to the disc body 140. The valve opening restricting portion 132 is at a position where the rotary valve body 202 can be returned to the valve closed state by the weight portion 123 attached to the insertion hole 204 when the valve is fully opened in FIG. 11, that is, the weight portion 123 is eccentric shaft 122 when the valve is fully opened. It is provided so that the position is slightly tilted in the valve closing direction.
A cylindrical connecting body 205 is connected to the body 111 via an O-ring 161 and an external pipe 201 is connected via the connecting body 205.

With such a configuration, normally, as shown in FIG. 10, the weight of the weight portion 123 exerts a clockwise force on the rotary valve body 202 about the eccentric axis 122, whereby the valve body spherical surface of the rotary valve body 202 is applied. The 143 closely seals the conical tapered surface 134 of the seat 21 to maintain the valve closed state and prevent backflow from the secondary side.

On the other hand, when the fluid pressure is applied from the primary side, the rotary valve body 202 rotates counterclockwise against the weight of the weight portion 123 due to this fluid pressure, and the valve is opened in FIG. 11 and the fluid flows. At this time, since the weight of the weight portion 123 is maintained in the valve closing direction, when the fluid pressure on the primary side disappears, the rotary valve body 202 is rotated clockwise by the weight portion 123, and FIG. It operates smoothly until the valve is closed and returns to the sealed state.

Similar to the above-described embodiment, since the peak of the valve closing force of the rotary valve body 202 is set to the intermediate opening degree of the rotary valve body 202, that is, between the valve opening degree fully closed and the valve opening fully opened, it is set to the primary side. When a minute pressure is generated, the fluid can flow while maintaining the valve opening opening of the intermediate opening, and at that time, the rotary valve body 202 operates in a stable state even if a pressure change occurs. , It is possible to prevent the occurrence of chattering phenomenon by preventing minute opening and closing operations.

12 and 13 show a third embodiment in which the rotary valve mechanism of the present invention is used as a vent valve.
In the valve body 80 of this embodiment, the cylinder body 81 is integrally provided as a valve unit, and in the cylinder body 81, a seat 82, a disc-shaped valve body 83 which is a rotary valve body, a rotary shaft 84, and a weight portion 85 are provided. Is provided. A rectangular penetrating portion 86 for mounting the rotating shaft 84 is formed at a position near the inner circumference of the cylinder body 81, and a mounting portion described later provided on the rotating shaft 84 is formed on the outer diameter side of the penetrating portion 86. An accommodating portion 88 in which the 87 and the weight portion 85 are accommodated is provided.

In the figure, the sheet 82 is formed by projecting an annular protruding seal portion 90 at the lower portion, and the valve seat contact surface 91 of the disc-shaped valve body 83 can be contact-sealed to the protruding seal portion 90. It is provided in. The seat 82 is mounted on the stepped surface 92 formed on the upper inner circumference of the cylinder body 81 so as to be sandwiched between the cylinder body 81 and the cap 12, and is a disk-shaped valve body. It consists of a stopper seal ring that can be closed by stopping the 83 at the valve closing position.

The disk-shaped valve body 83 is formed in a substantially arcuate cross section having a diameter larger than the diameter of the protruding seal portion 90 of the seat 82, and at this time, the valve seat contact surface 91 on the contact side with the seat 82 is formed. , The ridge seal portion 90 of the sheet 82 is in a state where it can be contacted by a line contact. A square concave portion 93 having a square shape is formed in the central portion of the bottom surface of the disc-shaped valve body 83.

The rotating shaft 84 is formed on the side to be attached to the cylinder body 81 with a diameter that allows play in the penetrating portion 86, and protruding locking portions 94 are formed on both sides of the rotating shaft 84. A mounting portion 87 for the weight portion 85 is formed on the rear end portion side (outer diameter side of the cylinder body 81) with respect to the rotating shaft 84, and a weight having an appropriate weight amount (mass) is formed on the mounting portion 87. The portion 85 is fixed.

A substantially L-shaped arm member 95 is integrally provided as a valve body support portion on the tip side (inner diameter side of the cylinder body 81) with respect to the rotating shaft 84, and the tip portion of the arm member 95 has a square recess 93. A spherical portion 96 having a playable diameter is formed.

The rotary shaft 84 is loosely fitted to the penetrating portion 86 and is mounted on the cylinder body 81 in a retaining state by the protruding locking portion 94, whereby the arm member 95 rotates around the rotary shaft 84 in the opening / closing direction of the valve. It will be possible. The spherical portion 96 at the tip of the arm member 95 is attached to the square recess 93 of the disc-shaped valve body 83, and the holding member 97 is attached from above to be attached by the universal joint structure.

With such a configuration, the valve diameter is substantially the same as the diameter of the extension ventilation pipe (pipe) 4, and the rotation shaft 84 is provided at a position near the inner circumference of the cylinder body 81, and is provided on the rotation shaft 84. In this case, the disc-shaped valve body 83 is provided so as to be openable and closable with respect to the stopper seal ring 82 via the arm member 95. An unbalanced torque that rotates in the valve opening direction via the rotation shaft 84 is generated during pressure to enable air to be taken in from the outside, and the weight of the weight portion 85 causes the inside of the cylinder body 81 to be under atmospheric pressure or positive pressure. An unbalanced torque that rotates in the valve closing direction is generated via the rotation shaft 84, and the valve is closed.

At that time, the disc-shaped valve body is formed by the moment in the valve opening direction due to the distance D3 from the center P4 of the rotating shaft to the center P5 of the spherical portion 96 and the weight portion 85 arranged on the opposite side of the disc-shaped valve body 83. Since the moment in the valve closing direction due to the weight of the 83 can be offset, even if the rotational moment acting on the disc-shaped valve body 83 when the valve is opened due to the negative pressure is very small, for example, at a negative pressure of about 30 to 50 Pa. Since the valve can be easily opened, it is possible to provide the valve body 80 having excellent responsiveness.

In the case of the valve body 80 as well, as in the case described above, the peak of the valve closing force of the disc-shaped valve body 83 is set between the valve opening fully closed and the valve opening fully opened, so that the disc-shaped valve is formed. Negative pressure can be reliably eliminated while suppressing the chattering phenomenon caused by repeated minute opening and closing operations of the body 83.

Further, since it is sufficient that the valve body 80 has a valve chamber having a width only within the rotation range of the disc-shaped valve body 83, the ventilation valve having a structure having a valve chamber that needs to be provided on the outside of the ventilation pipe. In comparison, delay is less likely to occur, and when a negative pressure is generated in the pipe, the valve opens immediately to eliminate this negative pressure.

In this embodiment, the weight portion 85 is provided to maintain the valve closed state at the time of atmospheric pressure or positive pressure, but the weight portion 85 is not limited to this, and a part of the disc-shaped valve body 83 may be thickened or may be used. By changing the material or the like, the weight of the weight portion may be reduced and the function of the weight portion may be exhibited.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the description of the embodiments, and is within the scope of the invention described in the claims of the present invention. Therefore, various changes can be made.

For example, an example in which the rotary valve mechanism of the present invention is applied to a vent valve has been described, but the rotary valve mechanism of the present invention can be provided in various other pipelines.

When the rotary valve mechanism of the present invention is applied to a vent valve, it may be inserted into the inspection port of the drain pipe system, or the vent pipe or drainage, in addition to the above-mentioned extension vent pipe and overflow edge. In addition to being used as a ventilation valve, an air valve, and an intake valve for relieving the negative pressure of the pipe, it can also be applied as a vacuum breaker for relieving the vacuum in the pipe.

When it is provided as a ventilation valve, it may be placed directly in the wall of an apartment house or the like, which is the piping space of the ventilation pipe, or it may be built in a resin box and placed in the wall. In this way, when the vent valve is arranged in the partition wall, it is preferable to arrange it so that the rotation axis is parallel to the wall surface or the longitudinal direction of the box. According to such an arrangement, the weight provided orthogonal to the rotation axis is in a position where it rotates in the longitudinal direction, and can rotate in a state where the inclination of the vent valve is small, so that the valve closed state is appropriate. Can be kept in.

Further, when the valve is provided as a vent valve, the valve unit structure has been described, but the present invention is not limited to this, and a valve mechanism other than the unit structure such as rotatably supporting the rotation axis of the valve body with a body is provided. The rotary valve mechanism of the present invention can also be applied to the vent valve having.

2 System body 4 Extension ventilation pipe 21 Seat (valve seat)
30 Ventilation flow path 80, 100 Valve body 83, 121, 202 Rotary valve body 84, 122 Eccentric shaft (rotary shaft)
85, 123 Weight part 95, 141 Valve body support part 140 Disc body

Claims (7)

It is a rotary valve mechanism that opens and closes the flow path by a rotary valve body, and by setting the peak of the valve closing force of the rotary valve body between the valve opening fully closed and the valve opening fully open, the rotary valve body A rotary valve mechanism characterized by suppressing the chattering phenomenon between the valve seat and the valve seat. The rotary valve mechanism according to claim 1, wherein the peak of the valve closing force of the rotary valve body is set between 5% and 50% of the valve opening degree. The rotary valve mechanism according to claim 1 or 2, which has a double eccentric structure in which the rotation center of the rotary valve body is doubly eccentric. The rotary valve mechanism according to claim 3, wherein the valve body support portion that supports the rotary valve body has an eccentricity of 40% or more with respect to the rotary valve body. The one according to any one of claims 1 to 4, wherein the rotary valve body is arranged at a position where the valve is opened by the weight of the disc body, and the valve is closed due to the balance with the weight portion provided on the disc body. Rotary valve mechanism. A vent valve according to any one of claims 1 to 5, wherein the rotary valve mechanism is used. A drainage pipe system according to claim 6, wherein the vent valve is mounted on an extension vent pipe or a lower overflow edge.

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