JP2820091B2 - Plug - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stopper which is screwed into the mouth of various containers and hermetically closes the mouth of the container.

[0002]

2. Description of the Related Art Referring to FIG. 1 showing a first embodiment of the present invention, the present applicant has disclosed a hollow plug 3 which is screwed into a mouth 2 of a container 1 and hermetically seals the mouth 2. In addition, a heat retention pot provided with an intake hole 4 for taking in air from the outside into the container, and an intake valve 5 for closing the intake hole 4 by contacting the inside from the inside of the container is provided.

[0003] This heat retaining pot is a simple one without a heater and a pouring mechanism, has a low-volume vacuum structure made of metal, has a liquid content sealed in a heat retaining state, and removes a lid if necessary. It is used as if drinking the contents liquid directly.

In such a heat retaining structure, even when the mouth 2 of the container 1 is closed by the plug 3, the heat of the content liquid gradually escapes to the outside, so that the temperature of the content liquid gradually decreases over time. . For this reason, if the closed state continues, the inside of the container 1 becomes a negative pressure, and even if the plug is unscrewed and removed, it often becomes difficult to remove the plug because it is attracted to the mouth 2 of the container 1.

The above-described intake hole 4 and intake valve 5 solve such a problem. When the temperature of the content liquid drops and the pressure in the container 1 decreases, the negative pressure caused by this causes the intake valve 5 to be pulled open toward the inside of the container 1 and sucks outside air from the intake hole 4. For this reason, it is possible to prevent the operability from being reduced due to the negative pressure as described above, while avoiding that the inside of the container 1 is suddenly exposed to the outside air and the temperature of the content liquid is rapidly reduced. Becomes

[0006]

However, the plug 3 also has an intake hole 41 at a part of the outer circumference where the intake hole 4 communicates with the outside air. Body 3
Washing and rinsing water may enter inside.

[0007] This water hardly comes out to the outside, and even if the plug is not translucent or transparent, the user may be confused by feeling the sign of water during handling.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a plug which can easily take out water even if water enters the hollow plug and is worrisome. It is assumed that.

[0009]

In order to achieve the above object, a plug body of the present invention according to claim 1 is provided with a plug body which is inserted into a mouth of a container and hermetically closes the mouth of the container. A lid body that covers the stopper body from above and is integrated by forcible fitting, and a part of the stopper body facing the inside of the vessel so that the inside of the stopper body and the inside of the vessel communicate with each other. And a peripheral wall of the lid has a skirt portion extending below a forcibly fitted portion with the plug body, and between the skirt portion and the side peripheral surface of the plug body. A gap for receiving the mouth of the container is provided, and the stopper is used by being inserted into the mouth of the container and sealed, or removed and removed, and the lid and the stopper body are used. It is accidentally detached during use due to the integrated structure by forcibly fitting It is used without problems. The stopper responds to a decrease in the pressure in the container due to a decrease in the temperature of the content liquid in the closed state in a conventional manner by the suction function of the suction hole and the suction valve. Water may gradually accumulate in the plug due to this suction function.

However, there is a gap between the skirt portion extending below the peripheral wall of the lid and the side peripheral surface of the plug body to receive the mouth of the container, and one of the lid and the plug body utilizing this gap. Alternatively, since the fitting can be released by the deformation of both and the two can be separated, even if water accumulates in the plug, it can be easily treated. Further, by inserting the stopper body into the inner periphery of the mouth of the container, the skirt portion of the lid functions as a cover for receiving the mouth of the container in the gap and covering the outer periphery of the mouth of the container, so that the well-sealed stopper is provided. You can get the status.

According to a second aspect of the present invention, in the first aspect of the invention, the plug body is made of a somewhat hard material, and the lid is provided between the inner peripheral surface of its own peripheral wall and the upper peripheral surface of the plug main body. A certain annular forcibly fitted portion is forcibly fitted in the axial direction and integrated with each other, and the skirt portion extends below the forcibly fitted portion of the plug body made of a resin softer than the plug body. A skirt portion extending below the forcibly fitted portion of the peripheral wall of the body has a gap between the skirt portion and the side peripheral surface of the plug main body, and the plug is held on the upper surface of the lid by holding the palm against the palm. When the skirt portion is squeezed on the diameter line, the skirt portion becomes a fulcrum near the fitting portion in the gripping direction, the lower end side of the skirt portion becomes a free end and falls inward, and in a direction perpendicular to the gripping direction. The lower end of the skirt expands outward and deforms. The lower end of the isolation portions collapse easily oval. This deformation has a similar tendency, though to a lesser extent, on the forcibly fitted portion on the inner periphery of the peripheral wall, and in the outwardly expanding portion, it floats outward from the forcibly fitted portion of the plug main body, and the forcible fit between the lid and the plug main body is released. . Therefore, it is not inadvertently removed, but in the work of gripping and squeezing the lid as described above, it is possible to easily remove the lid in a state where it can be reused without damaging each part. This is convenient for removing both the lid and the plug body, as well as forcibly fitting them by deformation on only the lid.

According to a third aspect of the present invention, in addition to the first aspect of the present invention, the stopper body and the lid are engaged with each other so as to be disengageable in the axial direction and both are prevented from rotating. It has a detent engaging portion, and the detent engaging portion is engaged at the same time as the lid body and the plug body are forcibly fitted, so that both can be prevented from rotating without any special work. The body serves as an operating portion for screwing and unscrewing the plug body, so that the plug body can be surely rotated to be attached and detached without any problem, and the non-fitting portion of the invention of claim 3 and the gripping direction are specified. In addition, it is possible to obtain an advantageous positional relationship for removing the forcible fit using the non-fitting portion.

According to a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, the annular forced fitting portion is partially omitted to form a non-fitting portion. When one or both of the body and the plug body is deformed, the forced fit is easily released.

According to a fifth aspect of the present invention, in the first aspect of the present invention, the lid is configured such that a portion of the lid body that is forcibly fitted to the plug body by its own deformation is disengaged. The forcible fitting can be disengaged and disengaged by the deformation of the lid body located at the position (1).

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the lid is located at a non-fitting portion where a forced fitting portion between the stopper and the plug body is partially omitted in the circumferential direction. The two parts on the diameter line different in the circumferential direction from the part which is located are used as pressing parts for deformation, and the skirt part when the skirt part of the lid is deformed into an elliptical shape by pressing by the pressing part. Because the expanded part of the hangs on the non-fitting part,
Due to the deformation of the lid, the forcible fit is easily released.

According to a seventh aspect of the present invention, in the fifth aspect of the present invention, the lid further deforms two positions on the diameter line passing through the non-fitting portion in which the fitting portion is omitted in a part of the circumferential direction. The non-fitting portion provides a relief allowance when the skirt portion of the lid is deformed into an elliptical shape by the pressing by the pressing portion, so that the deformation is facilitated, The deformation makes it easy for the forcing fit to come off.

According to an eighth aspect of the present invention, in any one of the sixth and seventh aspects of the present invention, the pressing portion has a visual display portion, and the pressing portion becomes clear to deform the lid. It is possible to easily and surely remove the lid and the plug body by forcibly fitting them and separating them.

According to a ninth aspect of the present invention, in addition to any one of the first to eighth aspects of the present invention, the intake valve further comprises a disc-shaped valve body,
A mounting shaft integrally formed upward at the center of the valve body and elastically fitted from below into a mounting hole provided in a bottom wall of the lid to press the valve body against the bottom wall; A simple structure with an intake hole formed integrally with the bottom wall and a valve body that is attached to the bottom wall with one touch by providing an intake hole at a portion where the valve body around the mounting hole of the wall is crimped. By assembling, the intake function can be satisfied and the cost can be reduced. In particular, the disc-shaped valve element provided around the mounting shaft can be attached to the bottom wall at any part in the circumferential direction. Since the crimping force is stable, the suction function can be stably performed over a long period of time.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will be described below with reference to FIGS.

(Embodiment 1) FIGS. 1 to 4 show a first embodiment of the present invention. This embodiment is a simple heat retaining pot without the above-mentioned heater and the pouring mechanism. As shown in FIGS. 1 to 3, a hollow that is screwed into the port 2 of the container 1 and hermetically closed the port 2. The stopper body 3 is screwed into the mouth 2 of the container 1 to tightly close the mouth 2 of the container 1, and a slightly hard stopper body 6 is placed over the stopper body 6 from above, and its peripheral wall 7a
A lid body made of a resin softer than the plug body 6, which is forcibly fitted in the axial direction at the annular forced-fitting portion 8 between the inner peripheral surface of the plug body 6 and the upper side of the side peripheral surface 6 a of the plug body 6 to be integrated with each other. 7 is comprised. Such a hard or soft material relation is mainly caused by the deformation of the lid 7 side, and the forcibly fitted portion 8
The purpose of this invention is to remove the forcible fitting as required and disassemble both to achieve the object of the present invention. The forcible fitting is not limited to this. Can be achieved, and the lid 7 and the plug body 6 can be achieved.
It can be removed by both deformations. The relationship between the hard and soft materials can be freely set depending on which member deformation is used. Further, the plug body 6 may be of a type in which a sealing portion is press-fitted into the mouth 2 and hermetically closed.

An intake hole 4 is provided at two places on the diameter line around the center of the bottom wall 6b of the plug body 6, and the wire body 6 and the lid 7 are provided.
Through the gap of the fitting portion with the outside. The intake valve 5 is made of, for example, an elastic sealing material such as silicon rubber, and has a mounting shaft 5a integrally formed at the center.
Is fitted elastically from below into a mounting hole 6c provided at the center of the bottom wall 6b, and a disc-shaped valve element 5b at the lower end of a mounting shaft 5a is inserted into the intake hole 4 from below, and accordingly, It is formed so that it is normally closed by crimping from the inner side.

As described above, with the simple structure and assembly of the intake hole 4 formed integrally with the bottom wall and the valve body 5b attached to the bottom wall with the mounting shaft 5a with one touch, the outside air accompanying the temperature drop of the liquid content can be obtained. To reduce the internal pressure and prevent the plug 3 from becoming unremovable, thereby reducing the cost. In particular, a panel provided around the mounting shaft 6c Since the pressing force to the bottom wall is stable in any part of the circumferential shape of the valve body 6b in the circumferential direction, the suction function can be stably performed for a long period of time.

The peripheral wall 7a of the lid 7 has a skirt portion 7b which extends L below the forcibly fitted portion 8 with the plug body 6;
A gap S for receiving the port 2 is provided between the skirt portion 7b and the side peripheral surface 6a of the plug body 6.

As described above, the plug according to the present embodiment is located between the upper side of the side peripheral surface 6a of the somewhat rigid plug main body 6 and the inner peripheral surface of the peripheral wall 7a of the lid 7 which is more flexible than the plug main body 6. The forcible fitting at the annular forcible fitting portion 8 firmly integrates. Therefore, the plug body of the present embodiment can be used without any problem without inadvertent detachment, and the skirt portion 7b extending below the forcibly fitted portion 8 of the peripheral wall 7a of the lid body 7 is provided with the plug body 6
A gap S is formed between the skirt portion 7 and the side peripheral surface 6a of the skirt portion 7.
When the skirt portion 7b is squeezed and pressed in the direction of arrow A on the diameter line as shown in FIG. 3A, the skirt portion 7b has the forcibly fitted portion 8 substantially as a fulcrum in this grasping direction, and As shown in the right half of (), the lower end of the skirt portion 7b is a free end and falls inward using the gap S to a position indicated by a virtual line. On the other hand, in conjunction with this, in the direction perpendicular to the gripping direction, the lower end of the skirt portion 7b has an arrow B as shown in the left part of FIG. 3 (c) and FIG. 3 (a).
It easily spreads outward as indicated by.

The lower end of the skirt 7b is crushed into an ellipse as shown in FIG. This deformation has the same tendency, though to a lesser extent, on the forcibly fitted portion 8 on the inner periphery of the peripheral wall 7a of the lid 7, and floats outward from the forcibly fitted portion 8 of the plug body 6 at the portion that expands outward. The forcible fit between the plug body 6 and the plug body 6 comes off as shown in the left and right portions of FIG. Therefore, the lid 7 is not inadvertently removed, but the lid 7 can be reused in a state where it can be reused without damaging each part in the work of grasping and squeezing the lid 7 as described above. 6 can be removed, and even if water accumulates in the plug body, it can be properly treated by discharging or wiping it.

However, since the lid 7 and the plug body 6 need only be separated from the water treatment so that they can be reused as necessary, the present invention is not limited to the above-described separation method in which only the lid is deformed. By forcibly bending a part of the peripheral wall of the plug body 6 at a position irrelevant to airtightness and by expanding and contracting it using the gap S, the forcible fitting of the forcibly fitted portion 8 can be removed. However, if the deformation of both the lid 7 and the plug main body 7 is utilized, it can be more easily removed.

The plug body 6 is screwed into a screw 11 formed on the inner peripheral surface of the mouth 2 of the container 1, and the skirt portion 7b of the lid 7 is
Covers the side peripheral surface 2a of the opening 2 of the container 1, and the opening 2 of the container 1 enters the gap S. Therefore, when the stopper body 6 is screwed into the inner periphery of the mouth 2 of the container 1, the skirt portion 7 b of the lid 7 receives the mouth 2 of the container 1 in the gap S, and
Since it functions as a cover for covering the outer circumference of the camera, a well-sealed plug can be obtained.

The forcibly fitted portion 8 is partially omitted as shown in FIGS. 2 and 3 (d) to form a non-fitted portion 8a. Therefore, when the skirt portion 7b is deformed into an elliptical shape by grasping and squeezing the lid 7, the lid 7
As shown in FIG. 3 (c), the forcible fit between the plug body 6 and the plug body 6 is easily detached, and it becomes easier to disassemble the plug body of the present embodiment by removing the lid body 7. If the direction in which the skirt portion 7b expands due to this elliptical deformation coincides with the position of the non-fitting portion 8a, the forcible fitting is more likely to come off. In this sense, it is preferable that the portion that grips and presses the lid 7 is displaced in the circumferential direction from the position of the non-fitting portion 8b, and is preferably shifted by about 90 °. In order to easily and surely achieve the pressing according to this condition, a concave portion 7c or the like for indicating the pressing position is provided on the side surface of the lid 7. This can also be something else that can be visually displayed, such as characters, patterns, marks, or any suitable combination of these.

Further, the plug body 6 and the lid 7 are connected to each other as shown in FIGS.
As shown in FIG. 2, the rotation preventing member 12 has a rotation preventing engagement portion 12 which engages so as to be able to be disengaged in the axial direction and stops the rotation. Therefore, the engagement between the lid 7 and the plug body 6 can be achieved at the same time as the above-mentioned engagement is achieved, and both can be prevented from rotating without any special work. , And the plug main body 6 can be securely rotated to be detached without any problem, and the non-fitting portion 8a and the gripping direction are specified to specify the non-fitting portion 8.
By using a, it is possible to obtain a positional relationship advantageous for removing the forced fit. The intake hole 41 may be provided in a part of the lid 7, but since the hole of the lid 7 can be seen outside, it is unsightly.

The bottom surface of the bottom wall 6b of the plug body 6 is shown in FIG.
As shown in FIG.
Thereby, even if steam condenses on the lower surface of the bottom wall 6b,
This is transmitted to the outer peripheral portion of the bottom wall 6b according to the curved surface,
Since the water is dropped into the container 1, it is possible to avoid a large amount of dew water 15 remaining on the lower surface of the bottom wall 6b. In addition, the lid 7 removed from the mouth 2 of the container 1 is placed on its back.
As shown in FIG. 5, there is often a primary inclination, but even if the inclination is as shown in FIG. 5, there is little water remaining on the lower surface of the bottom wall 6b. Since it is not necessary to worry about dropping during handling after removal, handling becomes easy.

The container 1 is composed of inner and outer containers 21 and 22 made of stainless steel, and is welded and joined to each other in a state where the upper ends of both mouths are tightly fitted to form the mouth 2 of the container 1. A screw 1 screwed into the mouth 21a of the inner container 21 with a plug body
1 and an annular seal seat surface 24 that abuts a seal member 23 made of silicon rubber or the like fitted into a groove 1d at the lower side of the plug body 6. A shoulder 26 is formed below the mouth of the outer container 22 to form a body of the container 1 flush with the skirt 7b of the lid 7.

The bottom of the outer container 22 is formed by welding another bottom plate 27, and the inner and outer containers 2 are attached to the center of the bottom plate 27.
Suction port 29 for making vacuum insulation space 28 between 1 and 22
Is provided and closed by a lid plate 31 after suction and exhaust, and are joined by brazing. This brazing is used to melt the brazing material by heat during suction and exhaust to join the inner and outer containers 21 and 22 while maintaining a predetermined degree of vacuum. A getter 33 is provided on the inner surface of the bottom plate 27 by a metal fitting 32 welded thereto.
Holding. This is to absorb the gas remaining in the heat-insulated space 28 between the inner and outer containers 21 and 22 which are vacuumed and sealed, or to be subsequently generated for some reason, and to stabilize the gas at a predetermined degree of vacuum.

(Embodiment 2) FIG. 5 shows a second embodiment of the present invention. This embodiment is different from the first embodiment in that the lower surface of the bottom wall 6b of the plug body 6 of the plug is formed flat as shown in FIG. The other components are the same as those of the first embodiment, and therefore, the same members are denoted by the same reference numerals, and overlapping description will be omitted.

In the present embodiment, the shape of the plug can be simple and simple.

However, there is a problem that the dew water condensed on the bottom wall 6b of the plug body 6 does not easily drip into the container 1, is hard to be held when the plug body is tilted as shown in the figure, and easily drops downward.

(Embodiment 3) FIG. 6 shows a third embodiment of the present invention. In the present embodiment, FIG.
As shown in (c), the lid 7 is deformed so that the forcibly fitted portion between the plug body 6 and the plug body 6 can be removed. The first and second points are that two positions on the diameter line different in the circumferential direction from the part where the non-fitting part 8a, a part of which is omitted, are used as pressing parts 7c for deformation. This is different from the second embodiment. Since other structures are the same as those of the first embodiment, the same members are denoted by the same reference numerals, and overlapping description will be omitted.

In the structure according to the present embodiment, the non-fitting portion 8a serves as a relief when the skirt portion 7b of the lid 7 is deformed into an elliptical shape by being pressed by the concave portion 7c showing the pressing portion. Since the allowance is given as shown in FIGS. 6A to 6C, the deformation is facilitated, and the deformation of the lid 7 makes it easy to remove the fitting.

[0038]

According to the plug of the first aspect of the present invention, the plug body and the lid body can be used normally without any problem without being accidentally detached by forcible fitting, and the gap between the lid body and the plug body is utilized. One or both of the deformations can be used to remove the forcible fit without damaging each part and thus separating the parts so that they can be reused. it can. Further, since the skirt portion of the lid functions as a cover for covering the outer periphery of the mouth of the container, a well-sealed state can be obtained.

According to the invention of claim 2, in the invention of claim 1, the skirt portion of the peripheral wall of the lid is squeezed at two locations on the diameter line so that the lower end of the skirt portion is crushed into an elliptical shape. This makes it possible to easily remove the forcible fit in the work of grasping and squeezing the lid as described above.

According to the third aspect of the present invention, in any one of the first and second aspects of the present invention, the lid is screwed and unscrewed with the lid by the detent between the lid and the plug body. As a part, the plug body can be securely rotated to be attached and detached without any problem, and the non-fitting part and the gripping direction of the invention of claim 3 are specified, and the non-fitting part is used to forcibly fit. Can be obtained to obtain an advantageous positional relationship for removing.

According to a fourth aspect of the present invention, in addition to any one of the first to third aspects of the present invention, when the lid is gripped and deformed, the lid and the plug main body are easily detached from each other. It is easier to break down the body.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects of the present invention, there is further provided an outermost lid 1
Since the forcible fit can be disengaged by the two deformations, the separating operation becomes easy.

According to a sixth aspect of the present invention, in the invention of the fifth aspect, when the skirt portion of the lid is deformed into an elliptical shape by the pressing by the pressing portion, the expanded portion of the skirt portion is not fitted to the skirt portion. Since it is hung on the portion, the forcible fit is easily released due to deformation of the lid.

According to a seventh aspect of the present invention, in the fifth aspect of the present invention, the non-fitting portion is provided with a clearance allowance when the skirt portion of the lid is deformed into an elliptical shape by being pressed by the pressing portion. Because of this, the deformation is facilitated, and the forcible fitting is easily released by the deformation of the lid.

According to an eighth aspect of the present invention, in any one of the sixth and seventh aspects of the present invention, in order to further deform the lid,
The pressing portion becomes clear, and the lid and the plug main body can be easily and reliably removed by forcibly fitting the lid to the plug body.

According to a ninth aspect of the present invention, in any one of the first to eighth aspects of the present invention, there is further provided a simple structure having an intake hole formed integrally with the bottom wall and a valve body attached to the bottom wall with one touch. By assembling, the intake function can be satisfied, and the cost can be reduced. In particular, the disc-shaped valve element provided around the mounting shaft can be connected to the bottom wall at any portion in the circumferential direction. Is stable, so that the suction function can be stably performed over a long period of time.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a heat retaining pot equipped with a plug according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of the plug shown in FIG.

FIG. 3 is a cross-sectional view, a cross-sectional bottom view, and a development view of a non-forced fitting portion showing a detached state of a forced fitting portion of the plug of FIG.

FIG. 4 is a perspective view showing a state in which the plug of FIG. 1 is tilted independently.

FIG. 5 is a perspective view showing a state in which a plug according to a second embodiment of the present invention is independently tilted.

FIG. 6 is a cross-sectional view, a cross-sectional bottom view, and a non-forced fitting portion showing a detached state of a forcibly fitted portion of a plug according to a third embodiment of the present invention when viewed from right and left in different directions at right angles. FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Container 2 port 3 Plug body 4 Inlet hole 5 Intake valve 5a Mounting shaft 5b Valve body 6 Plug body 6a Side peripheral surface 6b Bottom wall 6c Mounting hole 7 Lid 7a Peripheral wall 7b Skirt part 7c Recessed part 8a Non-fitting part 8a Fitting part 12 Detent engaging part

Claims (9)

(57) [Claims] 1. A plug body which is inserted into a mouth of a container and hermetically closes the mouth of the container, a lid which covers the plug body from above and is forcibly fitted by a fitting portion, an inside of the plug body and an inside of the container. And a suction valve provided at a portion of the plug body facing the inside of the container so as to communicate with the inside of the container, and closing an intake hole from outside by abutting from the inside of the container, and the peripheral wall of the lid has a skirt portion extending downward. ,
A plug body, wherein a gap is provided between the skirt portion and a side peripheral surface of the plug body to receive a mouth of the container. 2. The plug body is made of a somewhat hard material, and the lid body is forcibly fitted in the axial direction at an annular forcibly fitted portion between an inner peripheral surface of its own peripheral wall and an upper portion of a side peripheral surface of the plug body. The plug according to claim 1, wherein the plug is integrated with each other, and the skirt portion extends below a forcibly fitted portion of the plug main body made of a resin softer than the plug main body. 3. The stopper body according to claim 1, wherein the stopper body and the lid have a detent engaging portion for engaging and disengaging the stopper body in the axial direction so as to prevent rotation of both. A plug according to any of the preceding claims. 4. The plug according to claim 1, wherein a part of the forcibly fitted portion in the circumferential direction is omitted to form a non-fitted portion. 5. The plug according to claim 1, wherein the lid is forcibly fitted into and disengaged from the plug body by deformation of the lid. 6. The lid has a different diameter line in the circumferential direction from the portion where the non-fitting portion in which the forcibly fitted portion between the stopper body and the plug body is partially omitted in the circumferential direction is located. The plug according to claim 5, wherein two positions are formed as pressing portions for deformation. 7. The lid according to claim 5, wherein two positions on the diameter line passing through the non-fitting portion in which the forcibly fitting portion is omitted in a part in the circumferential direction are the pressing portions for deformation. Plug body. 8. The plug according to claim 6, wherein the pressing portion has a visual display portion. 9. An intake valve, comprising: a disc-shaped valve body; and a valve body integrally formed upwardly at the center of the valve body and elastically fitted from below into a mounting hole provided in a bottom wall of a lid body. The plug according to any one of claims 1 to 8, further comprising a mounting shaft for pressing the body against the bottom wall, wherein an intake hole is provided in a portion of the bottom wall where the valve body is pressed around the mounting hole. .