JPH0723409Y2 - Structure of synthetic resin drum mouth - Google Patents

Description

TECHNICAL FIELD The present invention relates to the structure of the mouth of a synthetic resin drum.

2. Description of the Related Art Conventionally, as an example of the structure of the mouth of a synthetic resin drum,
There is a partial cross-sectional view shown in FIG. 3 of the accompanying drawings. In this conventional example, the mouth portion 30 includes a cylindrical wall portion 31 integrally formed with the ceiling wall 1A so as to surround the wall portion of the drum, for example, the opening portion 2A of the ceiling wall 1A. There is. The cylindrical wall portion 31 has a female screw portion 32 on the inner peripheral wall. The first sealing surface 33, which is a circumferential surface extending in the screwing direction of the cap 40, is located above the cylindrical wall portion 31.
And an annular second sealing surface 34 extending inwardly from the lower portion of the first sealing surface 33 at a right angle. Second
The sealing surface 35 of the
35 are formed. The cap 40 for closing and sealing the opening 2A is a plug body formed of the same synthetic resin.
The plug main body 41 is provided with a male screw portion 42 that engages with the female screw portion 32 on the outer periphery of the lower portion thereof. A flange portion 43 is formed on the top of the plug body 41, and a lower surface 44 of the flange portion 43 provides a sealing surface.
By making the male screw portion 42 engage with the female screw portion 32 and screwing the cap 40, the sealing packing 45 becomes
First sealing surface 33 and second sealing surface 34, and sealing surface
By being brought into close contact with 44, the opening 2A is closed and sealed to the outside.

Further, as another conventional example of the structure of the mouth portion of the synthetic resin drum, there is a partial sectional view shown in FIG. 4 of the accompanying drawings. In this conventional example, the mouth portion 30A is
A wall portion of the drum, for example, a cylindrical wall portion integrally formed with the ceiling wall 1B so as to surround the opening 2B of the ceiling wall 1B.
It has 31A. The cylindrical wall portion 31A has a female screw portion 32A on the inner peripheral wall. A curved sealing surface 34A is formed on the inner periphery of the upper portion 33A of the cylindrical wall portion 31A. The cap 40A for closing and sealing the opening 2B has a stopper body 41A formed of the same synthetic resin, and the outer periphery of the lower portion of the stopper body 41A engages with the female screw portion 32A. A male screw portion 42A is formed. A flange portion 43A is formed on the top of the stopper body 41A, and the flange portion 4A is formed.
The lower surface 44A of 3A provides a sealing surface. The sealing packing 45A can be brought into close contact with the curved sealing surface 34A and the sealing surface 44A by screwing the cap 40A so that the male screw portion 42A is engaged with the female screw portion 32A. Thus, the opening 2B is closed and sealed to the outside.

Further, as still another conventional example of the structure of the mouth portion of the synthetic resin drum, there is a partial sectional view shown in FIG. 5 of the accompanying drawings. In this conventional example, the mouth portion 30
B includes a cylindrical wall portion 31B integrally formed with the ceiling wall 1C so as to surround the wall portion of the drum, for example, the opening portion 2C of the ceiling wall 1C. The cylindrical wall portion 31B has a female screw portion 32B on the inner peripheral wall. The inner peripheral wall of the cylindrical wall portion 31B below the female screw portion 32B has a conical sealing surface 34B.
Are formed. The cap 40B for closing and sealing the opening 2C is a stopper body 4 made of the same synthetic resin.
1B, and the female screw part 3
A male screw portion 42B that engages with 2B is formed. And
A first seal surface 43B and a second seal surface 44B are formed in the lower portion of the plug body 41B, and in order to prevent the sealing packing 46B from falling in the lower portion of the first seal surface 43B. The packing drop prevention protrusion 45B is formed. The male packing 42B is engaged with the female fitting 32B, and the cap 40B is screwed into the sealing packing 46B.
Is brought into close contact with the conical surface 34B and the first sealing surface 43B and the second sealing surface 44B, so that the opening 2C is closed and sealed to the outside.

Problems to be Solved by the Invention The conventional structure of the mouth portion as described above is the packing for the seal.
When the material of 45, 45A, 46B is rubber, sufficient sealing property can be obtained, and there is no particular problem. However, depending on the type of liquid contained in the drum, the rubber seal packing will corrode and the sealing performance will be impaired. Therefore, use a synthetic resin sealant with chemical resistance as the seal packing. You may want to. If the sealing packing is made of a hard synthetic resin, the chemical resistance will be good, but with the conventional mouth structure as described above, if the sealing packing synthetic resin used is hard, However, there was a problem that the sealing property deteriorates. This is because the sealing surfaces, to which the sealing packing must adhere, do not become sufficiently smooth due to residual stress when the synthetic resin drum is formed by blow molding. This is because the hard seal packing cannot sufficiently adhere to the insufficient sealing surface. In order to make the sealing surfaces smooth enough, it is only necessary to apply smoothing to the sealing surfaces after blow molding. In practice, however, such smoothing requires precise processing. However, the number of man-hours is increased, the machining time is required, and the cost is increased, which is not a practical solution.

On the other hand, it is conceivable to screw the caps 40, 40A, 40B strongly in order to improve the sealing property. However, in such a method, particularly in the case of the structure of the conventional example shown in FIG. 3 and FIG. Will cause problems such as. That is, the more the screwed in the cap 40 or 40A, the more the flange portion 43 or 43A of the cap is warped, and
The pressure applied to the seal surface 34 or the seal surface 34A increases, and the outer peripheral wall 31 or 31A of the mouth portion opens outward due to the influence of the pressure. Therefore, the degree of adhesion between the sealing packing 45 or 45A and each sealing surface does not increase only by screwing the cap, and conversely, the mouth portion is deformed, and the sealing performance deteriorates. In some cases, it may happen.

An object of the present invention is to provide a structure of a mouth portion of a synthetic resin drum which can solve the above-mentioned problems of the prior art.

According to the present invention, in the structure of the mouth portion of the synthetic resin drum that is closed and sealed by the screw cap, the mouth portion is formed integrally with the wall portion of the synthetic resin drum. A cylindrical wall portion that surrounds and has a threaded portion, the inner wall of the cylindrical wall portion below the threaded portion has a first sealing surface that extends downward in the screwing direction of the screw cap. A second seal surface extending inside a plane substantially orthogonal to the lower part of the first seal surface inside the first seal surface, and inside the first seal surface and the second seal surface. An edging groove extending downward from the second sealing surface along the outside of the sealing surface, wherein the threaded cap has a threaded portion that engages with the threaded portion of the cylindrical wall portion. A stopper body for closing the mouth, The outer peripheral wall below the threaded portion of the main body, when the threaded portion of the plug body is screwed into the threaded portion of the cylindrical wall portion, the outer peripheral wall and the first sealing surface of the cylindrical wall portion, Second
A third seal surface which is in close contact with the seal packing interposed between the third seal surface and the first seal surface and the second seal surface. The width and depth of the edging groove are
Sufficient to ensure that the deformation of the cylindrical wall does not substantially affect the second seal surface and the pressure exerted on the second seal surface does not substantially affect the first seal surface. It is supposed to be.

Action When the threaded portion of the plug body of the screw cap is screwed into the threaded portion of the cylindrical wall that surrounds the mouth of the synthetic resin drum, the third sealing surface of the plug body is attached to the sealing packing. Closely attach this sealing packing to the first
By closely contacting the seal surface and the second seal surface, the mouth of the synthetic resin drum is closed and sealed by the screw cap. At this time, the edging groove existing between the first sealing surface and the second sealing surface serves to prevent the deformation of the cylindrical wall portion from affecting the second sealing surface, The function of preventing the influence of the pressure applied to the first seal surface from affecting the first seal surface.

Embodiment Next, the present invention will be described in more detail with reference to FIGS. 1 and 2 of the accompanying drawings.

FIG. 1 is a partial cross-sectional view showing a structure of a mouth portion of a synthetic resin drum as an embodiment of the present invention before screwing the gap, and FIG. 2 is a structure of FIG. FIG. 6 is a partial cross-sectional view showing a state in which the cap of FIG. As shown in FIGS. 1 and 2, the structure of the mouth portion 10 of the drum of this embodiment is formed integrally with the ceiling wall 1 of the drum so as to surround the opening portion 2 and the female screw portion 12. Cylindrical wall part having
Equipped with 11. An inner side wall of the cylindrical wall portion 11 below the female screw portion 12 is a circumferential first sealing surface 13 extending downward in a screwing direction of a screw cap 20 made of a synthetic resin as described later. An annular second sealing surface 14 extending inward from the lower portion of the first sealing surface 13 at a right angle, and an edging groove provided between the first sealing surface 13 and the second sealing surface 14. Have 15 and.

The screw cap 20 includes a plug body 21 that has a male screw portion 22 that engages with the female screw portion 12 of the cylindrical wall portion 11 and closes the opening 2. The outer peripheral wall of the stopper body 21 below the male screw portion 22 has a conical shape, and has a first sealing surface 13 and a second seal surface 13 formed on the inner wall of the mouth portion 10 below the cylindrical wall portion 11. A third sealing surface 23 is provided which acts to bring the sealing packing 27 into close contact with the sealing surface 14. Furthermore, a straight portion 24 that extends linearly downward is formed in the lower portion of the conical outer peripheral wall that provides the third sealing surface 23, and in the lower portion of the straight portion 24, the straight portion 24 is formed. A packing drop-out preventing projection 25 is provided to prevent the seal packing 27 from falling from the portion 24. Further, on the upper portion of the straight portion 24, a stopper surface 26 that acts as described later is formed.

The sealing packing 27 mounted around the straight portion 24 of the plug body 21 may be made of rubber or hard synthetic resin, and in this embodiment, it is an annular body having a circular cross section. When the sealing packing 27 is attached to the straight portion 24, the gap between the outer peripheral surface of the straight portion 24 and the inner peripheral surface of the sealing packing 27 is equal to the first inner wall of the cylindrical wall portion 11 of the mouth portion 10. An eccentricity between the sealing surface 13 and the second sealing surface 14 is sufficient. On the other hand, seal packing
The outer diameter of 27 is preferably substantially the same as the diameter of the first sealing surface 13 of the cylindrical wall portion 11 of the mouth portion 10. The height of the straight portion 24 is set to an appropriate height so that the sealing packing 27 can freely move.

The height of the first sealing surface 13 formed on the cylindrical wall portion 11 of the mouth portion 10 is preferably ½ or more of the diameter of the circular cross section of the sealing packing 27.

Further, one of the important functions of the edging groove 15 formed between the first sealing surface 13 and the second sealing surface 14 is as follows. That is, when the mouth portion 10 is integrally blow-molded together with the drum body, the cylindrical wall portion 11 is deformed in any direction with the passage of time due to residual stress,
It is very difficult to maintain a perfect circle. Even if the cylindrical wall portion 11 is deformed in this way, if the edge cut groove 15 is provided, the second sealing surface 14 is not affected by the deformation of the cylindrical wall portion 11 and maintains a perfect circle. be able to.

Next, the operation when the cap 20 is screwed into the mouth 10 to close and seal the opening 2 will be described. When the male screw portion 22 of the stopper body 21 is engaged with the female screw portion 12 of the cylindrical wall portion 11 and the cap 20 is screwed into the mouth portion 10, the sealing packing 27 naturally becomes It hits the second sealing surface 14 and is sandwiched between the second sealing surface 23 and the third sealing surface 23 to be brought into close contact with the first sealing surface 13. Since the second sealing surface 14 is held in a perfect circle as described above,
Since there is no distortion, and therefore, the sealing packing 27 easily comes into close contact with the second sealing surface 14, the torque applied at this time is very small, and the cylindrical wall portion 11 has the cap 20.
It will not be deformed by strong screwing. Further, since the edging groove 15 is provided between the second seal surface 14 and the first seal surface 13, the pressure applied to the second seal surface 14 is directed toward the first seal surface 13. The first sealing surface 13 and the sealing packing 27 without any influence.
It does not cause a decrease in the degree of adhesion with. Therefore, the closing seal of the opening 2 can be completed without screwing the cap 20 too strongly. When the cap 20 is screwed into the mouth portion 10 in this way, the sealing packing 27 comes into contact with the stopper surface 26 provided on the upper portion of the conical sealing surface 24 to prevent further movement upward. Because of the limitation, it is possible to prevent the deformation of the mouth portion 10 and the damage of the sealing packing 27 due to the screwing of the cap 20 too much. FIG. 2 shows the cylindrical wall of the mouth 10.
The cap 20 is screwed into the inside 11 to show such a closed seal state.

Effect of the Invention According to the structure of the mouth portion of the synthetic resin drum of the present invention, even if the sealing packing made of the hard synthetic resin having excellent chemical resistance is used, or the cap has a very small screwing force, A complete seal, or occlusive seal, can be achieved.

[Brief description of drawings]

FIG. 1 is a partial sectional view showing a structure of a mouth portion of a synthetic resin drum as an embodiment of the present invention before screwing the cap, and FIG. 2 is a cap having the structure shown in FIG. 3 is a partial cross-sectional view showing a state in which a screw is screwed in, FIG. 3 is a partial cross-sectional view showing a structural example of a mouth portion of a conventional synthetic resin drum, and FIG. 4 is the same as FIG. 3 showing another conventional example. Partial sectional view of the fifth
The drawing is a partial cross-sectional view similar to FIG. 3 showing still another conventional example. 1 ... Synthetic resin drum ceiling wall, 2 ... Opening, 10 ...
… Mouth, 11 …… Cylinder wall, 12 …… Female thread, 13 …… First
Seal surface, 14 …… second seal surface, 15 …… edge cut groove,
20 …… Cap, 21 …… Bag body, 22 …… Male thread, 23…
… Third seal surface, 24 …… Straight part, 25 …… Protrusion, 26 …… Stopper surface, 27 …… Seal packing.

Claims (2)

[Scope of utility model registration request] 1. A structure of a mouth portion of a synthetic resin drum which is closed and sealed by a screw cap, is integrally formed with a wall portion of the synthetic resin drum, surrounds the mouth portion, and has a screw portion. A cylindrical wall portion, the inner wall of the cylindrical wall portion below the threaded portion having a first sealing surface extending downward in the screwing direction of the screw cap; and the first sealing surface. A second seal surface extending inwardly in a plane substantially orthogonal to the lower part of the first seal surface, and a second seal surface inside the first seal surface and outside the second seal surface. And a rim groove extending downward from the second sealing surface of the lever, and the threaded cap has a threaded portion that engages with the threaded portion of the cylindrical wall portion and closes the mouth portion. And a threaded portion of the stopper body. The outer peripheral wall below the outer peripheral wall and the first sealing surface and the second sealing surface of the cylindrical wall portion when the screw portion of the plug body is screwed into the screw portion of the cylindrical wall portion. A third sealing surface which is in close contact with the sealing packing interposed between the first sealing surface and the second sealing surface. The width and depth of the edging groove are such that the influence of the deformation of the cylindrical wall portion does not substantially affect the second seal surface and the influence of the pressure applied to the second seal surface is the first. Structure of the mouth of a synthetic resin drum, characterized in that it is sufficient to substantially not reach the sealing surface. 2. The third sealing surface is provided by a conical outer peripheral wall of a lower portion of the stopper body, and a straight portion extending downward in a substantially linear shape is provided at a lower portion of the conical outer peripheral wall. A portion is formed, and at the lower part of the straight portion, there is provided a packing slip-out preventing projection for preventing the seal packing from falling from the straight portion, and with the inner circumference of the seal packing. The structure of the mouth portion of the synthetic resin drum according to claim 1, wherein a gap corresponding to the eccentricity of the second sealing surface is provided between the straight portion and the outer periphery of the straight portion.