CN111336159B

CN111336159B - Plug for blocking fluid

Info

Publication number: CN111336159B
Application number: CN201911317501.1A
Authority: CN
Inventors: 车载玉; 金钟基; 裵亨燮
Original assignee: Joint Stock Co Motuole
Current assignee: Joint Stock Co Motuole
Priority date: 2018-12-19
Filing date: 2019-12-19
Publication date: 2022-10-21
Anticipated expiration: 2039-12-19
Also published as: CN111336159A; JP6924254B2; KR102281979B1; KR20200076530A; JP2020101285A

Abstract

The present invention provides a fluid-blocking plug which is coupled to a fluid hole formed in a hydraulic device, and which may include: a head portion having a predetermined diameter and a threaded portion formed on a peripheral surface thereof; and a seal portion extending from a lower end of the head portion and at least partially pressed against an inner peripheral surface of the fluid hole, wherein the seal portion may include a first seal portion disposed to form a predetermined angle with respect to a plane perpendicular to a central axis of the head portion, and a second seal portion disposed between the first seal portion and the head portion.

Description

Plug for fluid occlusion

Technical Field

The present invention relates to a fluid-blocking plug, and more particularly, to a fluid-blocking plug for preventing fluid leakage from a hydraulic device.

Background

Most of the devices or mechanisms using fluid force have a structure for storing fluid inside the device.

In general, a hydraulic device or a machine using a high hydraulic pressure is provided with a blocking cap for blocking a fluid guide hole after machining, so as to prevent an internal fluid from being exposed to the outside.

However, in the case of the screw type cover member, a pushing force (thrustload) is generated in a part due to a fastening torque transmitted to the screw, and there is a structural limitation in increasing the fastening torque for achieving a greater airtightness. Further, there is a problem that the airtightness performance varies depending on the machining accuracy of the screw.

Disclosure of Invention

Technical subject

The present invention has been made to solve the above problems, and an object of the present invention is to provide a fluid-blocking plug for preventing oil leakage from a hydraulic apparatus.

Technical scheme

The fluid-blocking plug of various embodiments of the present invention is coupled to a fluid hole formed in a hydraulic device, and may include: a head portion having a predetermined diameter and a threaded portion formed on a peripheral surface thereof; and a seal portion extending from a lower end of the head portion and at least partially pressed against an inner peripheral surface of the fluid hole, wherein the seal portion may include a first seal portion arranged to form a predetermined angle with respect to a plane perpendicular to a central axis of the head portion, and a second seal portion arranged between the first seal portion and the head portion.

Preferably, the second sealing surface of the second sealing portion may form an angle with respect to a plane perpendicular to the central axis of the head portion that is smaller than or equal to an angle formed by the first sealing surface of the first sealing portion with respect to a plane perpendicular to the central axis of the head portion.

Preferably, the fluid blocking plug may include: and an application member applied to the threaded portion of the head.

Preferably, the sealing portion may include a recess formed to be recessed upward from a central portion of the lower end surface.

Preferably, the head portion may include a tool coupling groove portion formed in a substantially star shape including six edge portions in cross section, and the six edge portions are respectively formed in a rounded shape.

Preferably, the fluid hole may include an inner screw part screw-coupled to the head and a press-contact part formed at a lower end portion of the inner screw part and having an inner circumferential surface with a wide top and a narrow bottom, and the first sealing part and the second sealing part may be respectively press-contacted to the inner circumferential surface of the press-contact part as the head is screwed along the screw formed at the inner screw part, thereby sealing the fluid hole.

The hydraulic apparatus sealing structure of various embodiments of the present invention includes the above-described fluid blocking plug, and the angle formed by the pressure contact portion and the center axis may be formed smaller than the angles formed by the first inclined portion of the first seal portion and the second inclined portion of the second seal portion and the center axis, respectively.

ADVANTAGEOUS EFFECTS OF INVENTION

The fluid-blocking plug of the various embodiments of the present invention may enhance the sealing effect by the first sealing portion and the second sealing portion.

Further, by providing the head with the screw, the sealing effect can be improved as the tightening force of the head is increased.

Further, since the diameter of the head portion and the diameter of the seal portion are formed substantially similarly, there is an effect that the depth of the bonding tool groove portion can be formed deep.

Drawings

Fig. 1 is a diagram illustrating a fluid blocking plug of various embodiments of the present invention.

Fig. 2 is a diagram illustrating a tool coupling groove portion of a fluid blocking plug according to various embodiments of the present invention.

Fig. 3 is a diagram illustrating a seal portion of a fluid-blocking plug according to various embodiments of the present invention.

Fig. 4 is a diagram conceptually illustrating fluid apertures in combination with the fluid blocking plug of various embodiments of the present invention.

Description of the symbols

100: head, 110: thread part, 150: tool-joining groove portion, 151: ridge, 152: valley portion, 200: sealing portion, 260: buffer, 220: first inclined portion, 210: first sealing surface, 240: second inclined portion, 230: second sealing surface, 250: recess, 300: hydraulic equipment, 301: fluid holes, 310: inside threaded portion, 330: and a crimping part.

Detailed Description

Hereinafter, for convenience of description, some embodiments of the present invention will be described with reference to the accompanying exemplary drawings. When reference numerals are given to components in each drawing, the same components are denoted by the same reference numerals as much as possible even when denoted by different drawings.

The terms or words used in the present specification and claims should not be limited to general or dictionary meanings, but should be interpreted as meanings and concepts conforming to the technical idea of the present invention on the basis of the principle that the inventor can appropriately define the concept of the terms in order to explain his own invention in an optimum manner. In addition, in the description of the constituent elements of the embodiments of the present invention, terms such as first, second, a, B, and the like may be used. Such terms are only used to distinguish one constituent element from another constituent element, and the nature, order, sequence, or the like of the constituent elements is not limited by the terms. When it is stated that a certain component is "connected" or "coupled" to another component, it is to be understood that the component may be directly connected or coupled to the other component, but another component may be "connected" or "coupled" to the other component.

Therefore, the embodiments described in the present specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention, and therefore, it should be understood that various equivalents and modifications which can replace the embodiments may be possible at the time of the present application. In addition, detailed descriptions of well-known functions and configurations which may unnecessarily obscure the gist of the present invention are omitted.

Hereinafter, the direction in which the tool is inserted into the head 100 may be described as an upper or upper side, and the opposite direction, i.e., the direction toward the inside of the fluid hole 301 may be described as a lower or lower side.

The fluid-blocking plug according to various embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 is a diagram illustrating a fluid-blocking plug according to various embodiments of the present invention, fig. 2 is a diagram illustrating a tool coupling groove portion 150 of the fluid-blocking plug according to various embodiments of the present invention, fig. 3 is a diagram illustrating a seal portion of the fluid-blocking plug according to various embodiments of the present invention, and fig. 4 is a diagram conceptually illustrating a fluid hole 301 to which the fluid-blocking plug according to various embodiments of the present invention is coupled.

The fluid blocking plug according to various embodiments of the present invention is used to seal a hole (fluid hole 301) that is open to the inside or outside of the fluid device 300 in a fluid (oil or gas) flow path formed in the fluid device 300. The present invention can be applied to most fields of apparatuses or machines using fluid force, and more particularly, to a field of machine element technology in which a blocking cover is used to block a fluid guide hole formed in the outside to prevent the internal fluid from being exposed to the outside in a hydraulic apparatus 300 or a machine using a high hydraulic force.

Referring to fig. 1 to 4, a fluid blocking plug of various embodiments of the present invention may include a head portion 100 and a sealing portion 200. The fluid-blocking plug may include a head portion 100 and a seal portion, and may be formed to extend in an axial direction (vertical direction) by a predetermined length. In one embodiment, the axial length L of the fluid-blocking plug may be formed such that when a dimensionless value of the axial length L of the fluid-blocking plug obtained by dividing the axial length L of the fluid-blocking plug by the nominal diameter M of the threaded portion of the head portion 100 is 0.1 to 1.0, a value of the axial length L1 of the seal portion to be described later is added to the dimensionless value.

The head portion 100 constitutes a predetermined region of the upper end portion of the fluid-blocking plug. A screw part 110 may be formed on the circumferential surface of the head part 100. The threaded portion 110 formed at the head 100 may include external threads. Such a threaded portion 110 of the head 100 may be threadedly coupled with the inner threaded portion 310 of the fluid hole 301. The head 100 may be cylindrical in shape with a prescribed diameter M.

A coating member (not shown) may be applied to the threaded portion 110. By such a coating member, an additional sealing effect may be provided together with the first and

second sealing parts

210 and 220 and 230 and 240. The coating member may include an Ethylene Glycol Dimethacrylate (EGDMA) material, but is not limited thereto.

A tool coupling groove portion 150 formed to be recessed downward may be disposed on an upper end surface of the head portion 100. A tool can be inserted into the tool coupling groove portion 150, and the tool can be tightened with a predetermined torque, thereby providing a tightening force for screw coupling between the screw portion 110 of the head portion 100 and the inner screw portion 310 of the fluid hole 301.

Referring to fig. 2, the tool coupling groove portion 150 may be formed in a substantially star shape having 6 ridge portions 151 in a cross section. This is to minimize face pressure when tightening the tool. In this case, each of the ridge portions 151 may be formed to be rounded at a predetermined radius of curvature R2, and valley portions 152 formed to be rounded at a predetermined radius of curvature R1 may be disposed between the ridge portions 151.

In one embodiment, the distance A1 between the ridge portions 151 that are symmetrical to each other may be formed such that a dimensionless value of the distance A1 between the ridge portions 151 that are symmetrical to each other, which is obtained by dividing the distance A1 between the ridge portions 151 that are symmetrical to each other by the nominal diameter M of the screw part, is 0.15 to 0.96.

When the value of the distance A1 between the ridge portions 151 is less than 0.15, it is difficult to maintain a fastening torque force for maintaining sufficient air-tightness of the plug, and when the value of the distance A1 between the ridge portions 151 exceeds 0.96, there is a problem that it is difficult to smoothly perform tool coupling.

At this time, the distance A2 between the mutually symmetrical trough portions 152 may be formed such that a dimensionless value of the distance A2 between the mutually symmetrical trough portions 152 divided by the value of A1 calculated above is 0.21 to 1.2.

Further, the depth H of the tool coupling groove portion 150 may be formed such that a dimensionless value of the depth H of the tool coupling groove portion 150 obtained by dividing the depth H of the tool coupling groove portion 150 by the value of A1 is 0.15 to 1.5.

Further, the curvature radius R1 of the trough 152 may be set such that the dimensionless value of the curvature radius R1 of the trough 152 obtained by dividing the curvature radius R1 of the trough 152 by the value A1 is 0.10 to 0.31, and the curvature radius R2 of the ridge 151 may be set such that the dimensionless value of the curvature radius R2 of the ridge 151 obtained by dividing the curvature radius R2 of the ridge 151 by the value A1 is 0.01 to 0.2.

That is, in the present invention, the tool coupling groove portion 150 formed in the head portion 100 is formed in a substantially star shape, and the depth H and the curvature radii R1 and R2 of the shape are set with reference to the longest distance (the distance between the ridge portions 151, A1), so that the maximum tightening torque can be defined and the surface pressure when tightening the tool can be minimized.

As the screw portion 110 of the head 100 is tightened to the inner screw portion 310 of the fluid hole 301 by a tool, as will be described later, the first and second seal portions may be pressed against the crimping portion 330 of the fluid hole 301 to induce plastic deformation or mutual contact, and by such deformation, at least surface contact or line contact may be formed between the first and second seal portions and the inner circumferential surface of the crimping portion 33.

Referring to fig. 3, the fluid blocking plug of various embodiments of the present invention may include a sealing portion 200. The sealing part 200 may be formed to extend downward from a lower end of the head part 100. The seal portion may be arranged coaxially with the head portion 100. The sealing portion 200 may be formed in a substantially wide-top and narrow-bottom shape. The sealing part 200 may include a buffer part 260, first sealing

parts

210, 220, and second sealing

parts

230, 240. The first and second sealing

parts

210 and 220 and 230 and 240 may be plastically deformed or contacted as the crimping part 330, which is pressed to the fluid hole 301 by tightening the head 100 with a tool, is pressed. In an embodiment, the axial length L1 of the sealing part 200 may be formed such that a dimensionless value of the axial length L1 of the sealing part 200, which is obtained by dividing the axial length L1 of the sealing part 200 by the nominal diameter M of the threaded part 110 of the head part 100, is 0.1 to 0.9.

The buffer part 260 may be formed to extend from a lower end of the head part 100 by a predetermined length. The buffer 260 may have a cylindrical shape with a predetermined diameter. The diameter D of the buffer portion 260 may be formed smaller than the nominal diameter of the threaded portion 110 of the head portion 100. In one embodiment, the diameter D of the buffer part 260 may be formed such that a dimensionless value of the diameter D of the buffer part 260, which is obtained by dividing the diameter D of the buffer part 260 by the nominal diameter M of the threaded part 110 of the head part 100, is 0.5 to 0.9. The

second sealing parts

230 and 240 may be formed to extend downward of the buffer part 260.

The

second sealing portion

230, 240 may include a second inclined portion 240 and a second sealing surface 230. The second inclined portion 240 may be formed to be inclined inward in the radial direction as it goes downward. That is, the diameters of the upper end portions of the

second sealing portions

230 and 240 may correspond to the diameter of the buffer portion 260, and may be formed to be wider at the top and narrower at the bottom as it goes downward. In this case, the side surfaces of the

second sealing parts

230, 240 may be described as the second inclined parts 240.

The second inclined part 240 may be formed to be inclined at a set angle θ 4 with respect to the central axis CL. This is to enable the second sealing part to contact the crimping part 330. In an embodiment, the second inclined portion 240 may be formed to be inclined at about 15 degrees with respect to the central axis.

The

second sealing portion

230, 240 may include a second sealing surface 230. The second sealing surface 230 may mean a lower end surface of the

second sealing part

230, 240. The second sealing surface 230 may be formed to be inclined at a set angle θ 2 with respect to a plane perpendicular to the central axis CL. This is because when the

second sealing parts

230, 240 for maintaining the sealing performance are in contact with the crimping part 330, the amount of plastic deformation or the timing of line contact of the

second sealing parts

230, 240 can be adjusted.

Further, the angle θ 2 formed by the second sealing surface 230 and a plane perpendicular to the center axis CL may be formed to be smaller than or equal to the angle θ 1 formed by the first sealing surface 210 and a plane perpendicular to the center axis CL.

In an embodiment, the second sealing surface 230 may be inclined at an angle of 5 to 25 degrees with respect to a plane perpendicular to the central axis CL. When the inclined angle θ 2 is less than 5 degrees or more than 25 degrees, the air-tightness may be degraded due to a problem of the amount of plastic deformation and contact timing of the

second sealing parts

230 and 240.

When the

second sealing part

230, 240 is pressed against the crimping part 330 of the fluid hole 301, at least a partial area of the second sealing surface 230 and/or the second inclined part 240 is plastically deformed so as to be in surface contact or line contact with the crimping part 330. The

first sealing part

210, 220 may be formed to extend downward of the

second sealing part

230, 240.

The

first sealing portion

210, 220 may include a first inclined portion 220 and a first sealing surface 210. The first inclined portion 220 may be formed to be inclined inward in the radial direction as it goes downward. The diameter of the upper end of the

first sealing portion

210, 220 may be smaller than the diameter of the lower end of the second sealing portion, and may be formed to be wider at the top and narrower at the bottom as it goes downward. In this case, a side surface of the

first sealing part

210, 220 may be described as the first inclined part 220.

The first inclined portion 220 may be formed to be inclined at a set angle θ 3 with respect to the central axis CL. This is because the initial contact timing of the

first sealing part

210, 220 can be adjusted according to the timing at which the

second sealing part

230, 240 initially contacts the crimping part 330. In an embodiment, the first inclined portion 220 may be formed to be inclined at about 18 degrees with respect to the central axis.

The

first sealing portion

210, 220 may include a first sealing surface 210. The first sealing surface 210 may mean a first seal portion lower end surface. The first sealing surface 210 may be formed to be inclined at a set angle θ 1 with respect to a plane perpendicular to the central axis CL. This is because, when the first sealing

parts

210, 220 are in contact with the crimping part 330, the amount of plastic deformation and the timing of line contact can be adjusted.

Further, the angle θ 1 formed by the first sealing surface 210 and a plane perpendicular to the center axis CL may be formed to be greater than or equal to the angle θ 2 formed by the second sealing surface 230 and a plane perpendicular to the center axis CL. This is because the predetermined deformation amount or the timing of line contact can be adjusted so that the first sealing portion and the second sealing portion maintain the same air-tightness performance.

In an embodiment, the first sealing surface 210 may be inclined at an angle of 5 to 25 degrees relative to a plane perpendicular to the central axis CL. When the inclined angle θ 1 is less than 5 degrees or exceeds 25 degrees, there may be a problem in maintaining the airtight performance due to a problem of the plastic deformation amount or the contact timing of the

first sealing part

210, 220.

Further, in an embodiment, the axial length L2 of the

first seal portion

210, 220 may be formed such that a dimensionless value of the axial length L2 of the

first seal portion

210, 220 obtained by dividing the axial length L2 of the

first seal portion

210, 220 by the nominal diameter M of the threaded portion of the head portion 100 is 0.05 to 0.3.

In an embodiment, the upper end diameter d2 of the first inclined portion 220 may be formed such that a dimensionless value of the upper end diameter d2 of the first inclined portion 220, which is obtained by dividing the upper end diameter d2 of the first inclined portion 220 by the nominal diameter M of the threaded portion of the head portion 100, is 0.16 to 0.98.

Further, in an embodiment, the lower end diameter d1 of the first inclined portion 220 may be formed such that an angle formed by a virtual line connecting the edge F of the second inclined portion 240 and the second sealing surface 230 and the edge E of the first inclined portion 220 and the first sealing surface 210 and a plane perpendicular to the center line CL is 30 to 90 degrees. This is because it is possible to simultaneously bring the first seal portion and the second seal portion into contact with the crimping portion 330 at the same angle or different angles or to change the ratio of the amount of plastic deformation of the first seal portion and the second seal portion to, for example, 5 or 6.

When the

first sealing part

210, 220 is pressed against the crimping part 330 of the fluid hole 301, at least a part of the area of the first sealing surface 210 and/or the first inclined part 220 is plastically deformed so as to be in surface contact with the crimping part 330.

According to various embodiments, the sealing part 200 may include a recess 250 formed to be depressed upward from a central portion of the lower end surface. As the inner circumferential surface of the concave portion 250 is pressurized by the hydraulic pressure acting in the upward direction, the first seal portion and/or the second seal portion can be pressurized radially outward by such hydraulic pressure. Thereby, the sealing efficiency of the sealing portion can be improved by the hydraulic pressure without giving an additional fastening force.

Referring to fig. 1, in an embodiment, the recess 250 may be formed to have a V-shaped cross section, but is not limited thereto, and as shown in fig. 3, the cross section may also be formed in a U-shape or a hemispherical shape.

The fluid-blocking plug according to the various embodiments of the present invention described above may be inserted into the fluid hole 301 formed in the hydraulic device 300 to seal the fluid hole 301.

Referring to fig. 4, the fluid hole 301 may include an inner threaded portion 310 that is threadedly coupled with the threaded portion of the head portion 100 of the fluid-blocking plug. An internal threaded portion corresponding to the threaded portion 110 of the head 100 may be formed at an inner circumferential surface of the inner threaded portion 310. In one embodiment, axial length L3 of internal threaded portion 310 may be formed such that a dimensionless value of axial length L3 of internal threaded portion 310, obtained by dividing axial length L3 of internal threaded portion 310 by nominal diameter M of threaded portion 110 of head 100, is 0.3 to 1.25. This is because, when the fluid-blocking plug is fastened to the fluid hole, it is possible to guide maintenance of a sufficient fastening force and prevention of interference between fastening.

Further, a pressure-bonding section 330 formed in a shape having a wider top and a narrower bottom may be disposed at the lower end of the inner screw portion 310 so as to have a smaller diameter toward the lower side. As the head 100 is tightened by a tool, the

first seal portions

210 and 220 and the

second seal portions

230 and 240 of the seal portion 200 are pressed against the pressure-bonding portion 330. As the first and second sealing

parts

210 and 220 and 230 and 240 are plastically deformed to be in surface contact or line contact with at least a partial region of the pressing part, respectively, a sealing effect can be provided. In an embodiment, an angle formed by the crimping portion and a central axis may be formed to be smaller than or equal to the first inclined portion and the second inclined portion. In an embodiment, the angle θ 5 of the inner circumferential surface of the crimping part 330 may be formed to be inclined by about 25 to 95 degrees with respect to a plane perpendicular to the center axis CL. This is because the ratio of the amount of plastic deformation and the contact timing of the first seal portion and the second seal portion can be changed by adjusting the angle.

As described above, the head 100 of the fluid blocking plug according to various embodiments of the present invention can be tightened with respect to the internal threaded portion 310 of the fluid hole 301 by a tool.

As the screw portion of the head portion 100 is screwed with the inner screw portion 310, the lower end portion of the sealing portion 200 can be moved downward. Further, the tightening of the tool can press at least a part of the

first seal portions

210 and 220 and the

second seal portions

230 and 240 against the pressure-bonding section 330. When the force to be compressed exceeds a predetermined amount, at least a partial region of the first and second sealing

parts

210, 220, 230, 240 may cause plastic deformation, and the portion causing plastic deformation may be in surface-to-surface contact with the inner side surface of the crimping part 330.

In the present invention, the first sealing

parts

210 and 220 are provided at the portions closest to the fluid, so that 1 time of sealing can be performed by plastic deformation of the first sealing

parts

210 and 220. Further, by providing the

second sealing parts

230, 240 on the upper sides of the first sealing

parts

210, 220, 2 times of sealing effect can be provided by plastic deformation of the

second sealing parts

230, 240. Further, by applying an application member to the screw part 110 of the head part 100 disposed above the sealing part, the leaked fluid can be sealed by the first sealing

parts

210 and 220 and the

second sealing parts

230 and 240 finally.

In the present invention, the concave portion 250 is provided at the lower end portion of the

first seal portion

210, 220, and the pressure of the fluid directly pressurizes the inner peripheral surface of the concave portion 250, thereby providing the pressurizing force to the radial direction outside of the

first seal portion

210, 220 or the

second seal portion

230, 240.

Further, by providing the head 100 with a screw portion that applies a tightening force in accordance with tightening of the tool, even if the tightening force continues to increase, tension is not generated between the head 100 and the seal portion, and there is no possibility of breakage.

That is, in addition to the torque generated with the tightening of the tool, an additional pressing force generated by hydraulic pressure may act on the first and/or second seal portions, thereby having an effect of being able to improve the sealing effect.

The above description of the case where all the components constituting the embodiments of the present invention are combined into one or are combined into one to operate does not mean that the present invention is necessarily limited to these embodiments. That is, all the components may be selectively combined and operated by one or more than one, without departing from the object scope of the present invention. In addition, unless otherwise stated to the contrary, the terms "including", "constituting" or "having" described above mean that the constituent element may be included, and thus should be interpreted as including other constituent elements as well, without excluding other constituent elements. Unless otherwise defined, all terms including technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms commonly used as terms defined in dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

The above description is merely an exemplary description of the technical idea of the present invention, and a person having ordinary skill in the art to which the present invention pertains can make various modifications and variations within a scope not departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed herein are intended to illustrate the technical idea of the present invention, and not to limit the technical idea of the present invention, and the scope of the technical idea of the present invention is not limited to these embodiments. The scope of the invention should be construed by the claims that follow, and all technical ideas within the scope of equivalents thereof should be construed to fall within the scope of the claims of the present invention.

Claims

1. A fluid-blocking plug that is coupled to a fluid hole formed in a hydraulic device, the fluid-blocking plug comprising:

a head portion having a predetermined diameter and a threaded portion formed on a peripheral surface thereof; and

a sealing part extending from a lower end of the head part and at least partially pressed against an inner circumferential surface of the fluid hole,

the seal portion includes a first seal portion disposed coaxially with the head portion and a second seal portion disposed between the first seal portion and the head portion,

the first seal portion includes a first inclined portion and a first seal surface, which form mutually different angles with respect to a central axis of the head portion with a first ridge E as a reference boundary line,

the second seal portion includes a second inclined portion and a second seal surface, which form mutually different angles with respect to the central axis of the head portion with a second ridge F formed on the upper side of the first ridge E as a reference boundary line,

the diameter of the upper end portion of the first sealing portion is formed smaller than the diameter of the lower end portion of the second sealing portion.

2. The fluid-blocking plug according to claim 1,

an angle formed by the second sealing surface of the second sealing portion with respect to a plane perpendicular to the central axis of the head portion is smaller than or equal to an angle formed by the first sealing surface of the first sealing portion with respect to a plane perpendicular to the central axis of the head portion.

3. The fluid blocking plug according to claim 1, comprising:

and an application member applied to the threaded portion of the head.

4. The fluid-blocking plug according to claim 1,

the seal portion includes a recess portion formed by being recessed upward from a central portion of the lower end surface.

5. The fluid-blocking plug according to claim 1,

the head portion includes a tool-engaging groove portion,

the tool coupling groove portion is formed such that a cross section thereof includes six edge portions, and the six edge portions are respectively formed as a round.

6. The fluid blocking plug according to claim 1,

the fluid hole includes an inner screw portion screwed to the head portion and a pressure contact portion formed at a lower end portion of the inner screw portion and having an inner circumferential surface that is wide at the top and narrow at the bottom,

as the head portion is screwed along the screw thread formed at the inner threaded portion, the first seal portion and the second seal portion are respectively crimped to the inner peripheral surfaces of the crimping portions, thereby sealing the fluid hole.

7. A hydraulic equipment enclosure structure including the fluid-blocking plug according to claim 6, characterized in that,

the crimping portion is formed to have an angle with a central axis smaller than an angle formed by the first inclined portion of the first sealing portion and the second inclined portion of the second sealing portion with the central axis, respectively.