阅读说明：本技术 密闭型套管 (Closed casing ) 是由 裵昌焕 李孝相 于 2017-02-07 设计创作，主要内容包括：本发明提供一种密闭型套管,该套管为密封结合具备第一外径及第一内径的第一管和具备第二外径及比第一外径大的第二内径的第二管,在上述第一管和上述第二管相互插入结合的状态下,设置于插入结合部位的密闭型套管,包括：主体,具备主体中心轴且呈柱状；贯通孔,在上述主体上,以上述主体中心轴为中心轴形成,并具备在安装状态下作为上述第二管一侧的开口的入口部,及在安装状态下作为上述第一管一侧的开口的出口部；其中,上述贯通孔在内壁的一个部位形成用于向上述插入结合部位施加密封压力的加压部,而作为上述加压部的内径的加压部内径小于上述第二外径。本发明提供的套管,通过优化加压部的长度,从根本上解决了制冷剂泄露及截面断裂的问题。(The present invention provides a sealed casing pipe in which a first pipe having a first outer diameter and a first inner diameter and a second pipe having a second outer diameter and a second inner diameter larger than the first outer diameter are sealingly joined, and which is provided at an insertion joint portion in a state where the first pipe and the second pipe are inserted and joined to each other, the sealed casing pipe including: a main body having a columnar shape and a main body central axis; a through hole formed in the body with the central axis of the body as a central axis, and including an inlet portion serving as an opening on the second pipe side in an attached state and an outlet portion serving as an opening on the first pipe side in an attached state; wherein the through hole has a pressurizing portion formed at one portion of an inner wall thereof for applying a sealing pressure to the insertion-coupling portion, and an inner diameter of the pressurizing portion is smaller than the second outer diameter. The sleeve provided by the invention fundamentally solves the problems of refrigerant leakage and section fracture by optimizing the length of the pressurizing part.)

1. A sealed sleeve having a first tube having a first outer diameter and a first inner diameter and a second tube having a second outer diameter and a second inner diameter larger than the first outer diameter, the sealed sleeve being provided at an insertion joint portion in a state where the first tube and the second tube are inserted into and joined to each other, the sealed sleeve comprising:

a main body having a columnar shape and a main body central axis;

a through hole formed in the body with the central axis of the body as a central axis, and including an inlet portion serving as an opening on the second pipe side in an attached state and an outlet portion serving as an opening on the first pipe side in an attached state;

wherein the through hole has a pressurizing part formed at one portion of the inner wall thereof for applying a sealing pressure to the insertion-bonding portion,

and a pressing portion inner diameter as an inner diameter of the pressing portion is smaller than the second outer diameter.

2. The hermetically sealed bushing of claim 1 wherein: the pressurization portion is formed near the outlet portion.

3. The hermetically sealed bushing of claim 2 wherein: the pressure section maintains the same inner diameter of the pressure section at all points from a second boundary section of the pressure section located at the corner of the outlet section to a first boundary section of the pressure section located at a predetermined position inside the through hole.

4. The hermetically sealed bushing of claim 3 wherein: the length of the pressurizing portion from the first boundary portion to the second boundary portion may be 20 to 40% of the length of the main body in the central axis direction.

5. The hermetically sealed bushing of claim 3 wherein: the through hole includes a pressurization introduction portion having an inner diameter gradually decreasing in a region from the inlet portion to the pressurization portion first boundary portion, so that a pressure applied to the second pipe by the sealed sleeve gradually increases as the sealed sleeve is gradually inserted into the second pipe side in the process of mounting the sealed sleeve.

6. The hermetically sealed bushing of claim 5 wherein: the inner wall of the through hole constituting the pressure introduction portion is formed of a curved surface.

7. The hermetically sealed bushing of claim 6 wherein: the outer peripheral line of the cross section of the pressure introduction part on the basis of the plane including the center axis of the main body is a convex arc having a constant radius of curvature.

8. The hermetically sealed bushing of claim 1 wherein: the pressurizing part includes a front-end pressurizing part and a rear-end pressurizing part, and the inner diameter of the front-end pressurizing part, which is the inner diameter of the front-end pressurizing part, is larger than the inner diameter of the rear-end pressurizing part, which is the inner diameter of the rear-end pressurizing part.

9. The hermetically sealed bushing of claim 1 wherein: the main body has a recognition structure that can recognize the directions of the inlet and outlet portions from each other by tactile sensation.

10. A method of using the hermetically sealed bushing of any of claims 1-9 comprising:

i) inserting the hermetically sealed sleeve into the first tube so that the inlet portion is close to the insertion coupling portion;

ii) inserting the first tube into the second tube with the hermetically sealed sleeve inserted;

iii) inserting the end of the second pipe end into the inlet side of the sealed sleeve;

iv) a step of inserting the second pipe along the curved surface of the pressure introduction part with the pressure being applied to the outlet part side end part of the sealed type sleeve so that the tip of the second pipe end part reaches the first boundary part of the pressure section;

v) a step of, as pressure is applied to the outlet portion side end portion of the hermetically sealed sleeve, causing the tip of the second pipe end portion to reach the second boundary portion of the pressurization portion;

vi) the pressurization part applies sealing pressure to the insertion joint part to complete the mutual sealing connection of the first pipe and the second pipe.

Technical Field

The present invention relates to a sealed bushing for use in household, industrial, commercial, and vehicular air conditioning systems and refrigeration/freezing systems using refrigerant lines, and more particularly, to a sealed bushing which is provided on an outer circumferential surface thereof so that an operator can easily recognize a direction, has a length of a pressurization part optimized to improve sealing performance, and has a certain curved surface formed at one portion inside a through hole to prevent a defect during installation, and which is capable of easily connecting lines having different sizes.

Background

In a household, industrial, commercial, and vehicle air conditioning system (air conditioner) and a household, industrial, and commercial refrigerating/freezing system (refrigerator, freezer, etc.), a refrigerant filled at high pressure is used, and a pipe line forming a flow path of the refrigerant needs to be tightly sealed at a joint seam, and a sealed sleeve is used as a member for the sealed joint.

Korean registered patent No. 20-0369210 (title of the invention: improved structure of sleeve for air-conditioning refrigerant line, hereinafter referred to as "prior art 1") discloses an improved structure of a sleeve for air-conditioning refrigerant line, in which an introduction part is connected to a sleeve for wall, a sleeve for balcony wall and an arc-shaped pipe are connected by a connection pipe, and in the sleeve for air-conditioning refrigerant line, which is connected between the other end of the arc-shaped pipe and the sleeve for wall by an extension pipe, the sleeve for wall is integrally formed with support legs at upper and lower parts on both sides thereof, and is provided with extension pipe parts each protruding outward, the pipe formed in the middle part thereof is divided into two pipes which are inserted and slid into each other and have a variable length, the pipe located on the indoor side is inserted into the inner surface of the pipe located on the outdoor side to be varied, the two ends of the arc-shaped pipe are extended and divided into two pipes which are inserted and slid into each other and have a variable length, and the upper and lower surfaces of the arc-shaped pipe located on the outer side, the supporting legs with a certain height along the length direction are integrally formed, the two ends of the sleeve for the balcony wall are cut off at an angle of 45 degrees and are inserted into and slide with each other, the length of the sleeve is variable, the supporting legs with a certain height along the length direction are integrally formed on the upper surface and the lower surface of the sleeve positioned on the outer side, and the covers with protruding ends with fixing holes are integrally formed on the outer side in a detachable insertion mode on the expanding pipe parts on the two ends.

Disclosure of Invention

Problems to be solved by the invention

The technical problem to be solved by the invention is as follows: the first problem is that the above-described mounting work takes too much time; the second problem is that when pipes with different inner and outer diameters are connected, the sealing and the combination are inconvenient; the third problem is that it is difficult for the operator to distinguish the direction of the sleeve.

Technical problems to be solved by the present invention are not limited to the above technical problems, and other technical problems not mentioned will become apparent to those skilled in the art from the following.

Means for solving the problems

In order to solve the above-described problems, the present invention provides a sealed sleeve pipe which is provided at an insertion joint portion in a state where a first pipe having a first outer diameter and a first inner diameter and a second pipe having a second outer diameter and a second inner diameter larger than the first outer diameter are sealingly joined to each other, the sealed sleeve pipe including: a main body having a columnar shape and a main body central axis; a through hole formed in the body with the central axis of the body as a central axis, and including an inlet portion serving as an opening on the second pipe side in an attached state and an outlet portion serving as an opening on the first pipe side in an attached state; wherein the through hole has a pressurizing portion formed at one portion of an inner wall thereof for applying a sealing pressure to the insertion-coupling portion, and an inner diameter of the pressurizing portion is smaller than the second outer diameter.

In addition, the pressurizing portion is formed near the outlet portion.

The pressure section maintains the same inner diameter of the pressure section at all points from a second boundary section of the pressure section located at the corner of the outlet section to a first boundary section of the pressure section located at a predetermined position inside the through hole.

The length of the pressurizing portion from the first boundary portion to the second boundary portion may be 20 to 40% of the length of the main body of the pressurizing portion in the central axis direction.

The through hole includes a pressurization introduction portion having an inner diameter gradually decreasing in a region from the inlet portion to the pressurization portion first boundary portion, so that a pressure applied to the second pipe by the sealed sleeve gradually increases as the sealed sleeve is gradually inserted into the second pipe side in the process of installing the sealed sleeve.

Further, the inner wall of the through hole constituting the pressure introduction portion is formed by a curved surface.

Further, a cross-sectional peripheral line of the pressure introduction portion based on a plane including the central axis of the main body is a convex arc having a constant radius of curvature.

The pressurizing section includes a front end pressurizing section and a rear end pressurizing section, and the front end pressurizing section has an inner diameter larger than the rear end pressurizing section.

The main body has a recognition structure that can recognize the directions of the inlet and outlet portions by tactile sensation.

The identification structure is formed of a male engraved structure that protrudes relatively to the surface of the body or a female engraved structure that is recessed relatively to the surface of the body.

In addition, the positive-engraving structure or the negative-engraving structure has a step difference of 0.2-2 mm with respect to the surface of the main body.

The difference between the inner diameter of the pressurizing part and the second outer diameter is 5-15% of the second outer diameter.

The difference between the inner diameter of the front end pressurizing part and the inner diameter of the rear end pressurizing part is 1-10% of the inner diameter of the rear end pressurizing part.

The use method of the sealed casing of the present invention includes: inserting the sealed sleeve into the first tube so that the inlet portion is close to the insertion joint portion; inserting and coupling the first tube to the second tube in a state where the sealed sleeve is inserted; inserting the end of the second pipe into the inlet of the sealed casing pipe; a step of inserting the second pipe along the curved surface of the pressurization introduction part by applying pressure to the outlet part side end part of the sealed sleeve pipe so that the end of the second pipe end part reaches the first boundary part of the pressurization part; applying pressure to the outlet-side end portion of the sealed sleeve so that the end of the second pipe end portion reaches a second boundary portion of the pressurization portion; the pressing part applies a sealing pressure to the insertion joint part, thereby completing the mutual sealing connection of the first pipe and the second pipe.

Effects of the invention

According to the embodiment of the present invention, there is a first effect of fundamentally solving the refrigerant leakage and the cross-sectional fracture by optimizing the length of the pressurization part; a second effect of minimizing the defect of the cross-sectional fracture by optimizing the shape of the pressure introduction part which is an excessive section from the inlet part to the pressure part; a third effect that an operator can easily recognize the direction of the sleeve by the recognition structure, thereby reducing errors in judging the use of the sleeve in the front-rear direction by mistake; fourth effect, the closed type casing can be quickly installed by using the jig.

The effects of the present invention are not limited to the above-described effects, and may include all effects that can be derived from the detailed description of the present invention or the claims.

Drawings

Fig. 1 is a schematic view showing a cross section of a center shaft of a hermetically sealed bushing including an embodiment of the present invention;

FIG. 2 is a longitudinal cross-sectional view of the hermetically sealed bushing in accordance with one embodiment of the present invention;

fig. 3 is a sectional view showing a state where the hermetically sealed grommet according to the embodiment of the present invention is inserted and coupled and two pipes having different outer diameters and inner diameters are sealed;

fig. 4 is a longitudinal sectional view showing a state where the pressing portion of the sealed bushing according to the embodiment of the present invention includes a front end pressing portion and a rear end pressing portion;

fig. 5 is a sectional view of the identification structure of the hermetically sealed bushing according to an embodiment of the present invention, which is formed by engraving.

Reference character

10: closed casing

20: first pipe

30: second pipe

100: inlet section

200: outlet section

300: through hole

310: pressurization part

311: front end pressurizing part

312: rear end pressing part

330: first boundary part of pressurization part

320: second boundary part of pressurizing part

340: pressure introduction part

400: identification structure

Detailed Description

The present invention will be described below with reference to the accompanying drawings. The present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to more clearly explain the present invention, the contents irrelevant to the explanation are omitted, and the same or similar structures are given the same reference numerals throughout the specification.

In the present invention, the term "a part" is "connected (connected, contacted, or combined) with another part" includes not only a case of "direct connection" but also a case of "indirect connection" through another member. In the specification, when a part "includes" a certain component, other components may be included instead of excluding the certain component unless the contrary description is expected.

The terminology used in the description is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Where the context does not differ significantly, singular references include plural references. In the present specification, terms such as "including" or "having" or the like indicate that there are features, numbers, steps, actions, structures, components, or combinations thereof described in the specification, but do not preclude the presence or addition of one or more other features, numbers, steps, actions, structures, components, or combinations thereof.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

The sealed casing pipe of the present invention includes a first pipe having a first outer diameter and a first inner diameter and a second pipe having a second outer diameter and a second inner diameter larger than the first outer diameter, which are hermetically joined to each other, and is provided in a shape of an insertion joint portion in a state where the first pipe and the second pipe are inserted and joined to each other. The insertion joint portion indicates a portion where the first tube and the second tube are joined and contacted and an adjacent region.

A hermetically sealed bushing comprising: a main body having a columnar shape and a main body central axis; an inlet part formed on the main body by using the central axis of the main body as a central axis and used as an opening on one side of the second pipe in a mounting state; and a through hole having an opening serving as the first pipe side in an attached state. The main body may be a columnar body, and may include not only a column, a hexagonal column, and a square column, but also a column having various cross sections.

In addition, the through hole has a pressurizing portion formed at one portion of the inner wall thereof for applying a sealing pressure to the insertion bonding portion.

The inner diameter of the pressurizing part is smaller than the second outer diameter. The pressurized inner diameter portion is larger than the first outer diameter, which is related to the installation process of the sealed sleeve, specifically, the sealed sleeve is first inserted into the first tube, then the first tube and the second tube are combined, and then the sealed sleeve is pushed toward the insertion combination position for installation.

The pressurizing portion is formed adjacent to the outlet portion. In the process of pushing the sealed casing toward the insertion joint portion to install the sealed casing, considering that the inlet portion first enters the insertion joint portion and the outlet portion finally enters the insertion joint portion, the sealing performance of the sealed casing is improved only by forming the pressurizing portion at a portion adjacent to the outlet portion.

The pressure section maintains the same inner diameter of the pressure section at all points from a second boundary section of the pressure section located at the corner of the outlet section to a first boundary section of the pressure section located at a predetermined position inside the through hole. In general, if the pressure portion is formed obliquely in consideration of the fact that the outer diameters of the first pipe and the second pipe are the same at all points, the sealing performance cannot be formed in a wide range. The second boundary part of the pressurizing part and the first boundary part of the pressurizing part are formed along the inner wall of the through hole.

The length of the pressing portion in the central axis direction of the main body (pressing portion length) is defined as the length from the second boundary portion of the pressing portion to the first boundary portion of the pressing portion, and preferably, the length of the pressing portion is 20 to 40% of the length of the main body in the central axis direction of the main body (main body length). If the length of the pressurizing portion is less than 20% of the length of the main body, the pressurizing portion is broken during use to cause leakage, and if the length of the pressurizing portion exceeds 40% of the length of the main body, the length of the pressurizing introduction portion is finally shortened, which increases the impact force applied to the pressurizing introduction portion, and may cause breakage of the sealed conduit.

Best mode for carrying out the invention

The best embodiment of the present invention is as follows:

a hermetic bushing provided at an insertion joint portion in a state where a first tube having a first outer diameter and a first inner diameter and a second tube having a second outer diameter and a second inner diameter larger than the first outer diameter are joined to each other in a sealing manner, the hermetic bushing comprising:

a main body having a columnar shape and a main body central axis;

a through hole formed in the body with the central axis of the body as a central axis, and including an inlet portion serving as an opening on the second pipe side in an attached state and an outlet portion serving as an opening on the first pipe side in an attached state;

the through hole is provided with a pressurizing part which is formed on the inner wall from a pressurizing part second boundary part positioned at the edge of the outlet part to a pressurizing part first boundary part positioned at a certain position in the through hole and applies sealing pressure to the insertion and combination part;

a pressurizing portion inner diameter that is an inner diameter of the pressurizing portion is smaller than the second outer diameter and is maintained the same at all points from the pressurizing portion second boundary portion to the pressurizing portion first boundary portion;

a pressure introduction portion having an inner diameter gradually decreasing in a region from the inlet portion to the first boundary portion of the pressure portion, so that a pressure applied to the second pipe by the sealed sleeve gradually increases as the sealed sleeve is gradually inserted into the second pipe during the installation of the sealed sleeve;

the inner wall of the through hole forming the pressure introduction part is formed by a curved surface;

the outer peripheral line of the cross section of the pressure introduction part on the basis of the plane including the central axis of the main body is a convex arc having a constant radius of curvature.

Next, examples and experimental examples will be explained.

< example 1>

A first pipe having a first outer diameter and a first inner diameter and a second pipe having a second outer diameter and a second inner diameter larger than the first outer diameter are prepared, a length of the pressurization part is set to 20% of a length (10mm) in a central axis direction of the main body to manufacture a sealed sleeve, the sealed sleeve is connected to the first pipe, and the first pipe is inserted into the second pipe, thereby realizing insertion coupling and sealing of the first pipe and the second pipe.

< example 2>

The insertion bonding and sealing of the hermetically sealed sleeve and the first and second tubes were achieved in the same manner as in example 1, except that the length of the pressurizing portion was made 30% of the length in the central axis direction of the main body.

< example 3>

The insertion bonding and sealing of the hermetically sealed sleeve and the first and second tubes were achieved in the same manner as in example 1, except that the length of the pressurizing portion was 40% of the length in the central axis direction of the main body.

< comparative example 1>

The insertion bonding and sealing of the hermetically sealed sleeve and the first and second tubes were achieved in the same manner as in example 1, except that the length of the pressurizing portion was set to 15% of the length in the central axis direction of the main body.

< comparative example 2>

The insertion bonding and sealing of the hermetically sealed sleeve and the first and second tubes were achieved in the same manner as in example 1, except that the length of the pressurizing portion was set to 45% of the length in the central axis direction of the main body.

< Experimental example 1>

In the state where the sealed type bushings of examples 1, 2, 3, 1, and 2 and the first and second pipes (second outer diameter: 5.6mm) were connected, the sealed type bushings and the first and second pipes were sealed by inserting and joining them with a hydraulic jig, and after sealing, a refrigerant (under the supply pressure of a normal refrigerant used in an automobile, an air conditioner, and a refrigerator) was supplied to the line pipe and the state of the sealed type bushings was observed. The results are shown in Table 1.

[ Table 1]

	Sealing state
		Example 1 (20%)	OK
Example 2 (30%)	OK
		Example 3 (40%)	OK
Comparative example 1 (15%)	Leakage occurs
		Comparative example 2 (45%)	Occurrence of fracture

As shown in the results of table 1, the first tube and the second tube sealed by the hermetically sealed sleeves of examples 1 to 3 of the present invention did not crack or leak the fluid. However, in the case of comparative example 1, a fluid leakage phenomenon occurs, and in the case of comparative example 2, a cross-sectional fracture phenomenon of the sealed casing tube occurs during sealing.

In order that the pressure applied to the second pipe by the sealed sleeve gradually increases as the sealed sleeve is gradually inserted into the second pipe during the installation of the sealed sleeve, the pressure introduction portion includes a through hole, and the inner diameter of the through hole gradually decreases in a region from the inlet portion to the first boundary portion of the pressure portion. With the above configuration, the change in the pressure applied to the main body of the sealed sleeve by the second tube can be gradually changed in the pressure introduction portion from the initial stage of installation until the distal end portion of the second tube reaches the pressure portion, and it is possible to prevent the second tube and the sealed sleeve from colliding with each other and receiving a large impact force during installation.

The inclination (gradient) of the gradual decrease may be proportional (linear function) to the length of the body in the central axis direction, but it is preferable that the inner wall of the through hole constituting the pressure introduction portion is formed in a curved surface.

Further, a cross-sectional peripheral line of the pressure introduction portion based on a plane including the center axis of the main body is a convex arc having a constant radius of curvature. With the above configuration, the rate of increase in pressure increases as the sealed sleeve moves in the main body center axis direction at the initial stage of installation (the pressure applied to the second tube by the sealed sleeve is small), and the rate of increase in pressure at which the sealed sleeve continues to move in the main body center axis direction decreases after installation (the state in which the pressure applied to the second tube by the sealed sleeve has already increased). The above process can reduce the defects of the closed sleeve such as section fracture. In addition, the sectional peripheral line of the pressure introduction part according to the plane including the central axis of the body may be designed to be a convex curve.

In contrast, when the cross-sectional peripheral line of the pressure introduction portion according to the plane including the central axis of the body is designed to be concave, such a structure can lead to a cross-sectional fracture (a defective rate of 10%) of the closed type bushing. This occurs because the pressure change becomes large instead after the middle of the mounting process (the state in which the pressure applied by the sealed sleeve to the second tube has become large), and the impact force to which the sealed sleeve is subjected only becomes large.

When the cross-sectional peripheral line of the pressure introduction portion from the plane including the central axis of the main body is designed to be a straight taper shape, the sealed bushing has a lower defect rate (5%) than the case of the concave arc, but has a higher defect rate than the case of the convex arc (0%).

In this case, the radius of curvature of the arc may be determined by the length of the pressure introduction portion, the introduction contact depth (the distance from the position where the inner wall of the pressure introduction portion and the second pipe are in first contact (in a state where no pressure is generated) to the inlet portion), and the radial distance (the difference in pressure level, the difference in second outer diameter and pressure inner diameter) from the introduction contact depth to the first boundary portion.

The curvature decreases (the radius of curvature increases) as the length of the pressure introduction portion increases.

When the introduction depth is increased, the curvature is increased (the radius of curvature is decreased) in the second tube having the same size.

When the pressure step becomes large, the curvature becomes large (the radius of curvature becomes small) in the second pipe of the same size.

Meanwhile, the length, introduction depth, and pressure step of the pressure introduction portion become factors that determine the overall size (length and width) of the sealed bushing of the present invention.

In the present invention, the curvature of the peripheral line of the cross section according to the plane including the central axis of the main body is not limited to a specific case, because such curvature may vary according to the overall size of the hermetic sleeve.

The inner diameter of the inlet part is related to the introduction depth, and when the inner diameter of the inlet part is increased, the introduction depth is increased.

The pressure step difference (difference between the inner diameter of the pressurizing portion and the second outer diameter) is the most important factor that determines the force applied to the seal joint portion by the hermetically sealed bushing of the present invention. The pressure step difference can be set to be 5-15% of the second outer diameter. If the pressure step difference is too large, the outer shape of the sealed sleeve becomes unnecessarily long because the pressure introduction portion becomes longer, and if the pressure step difference becomes smaller, the sealing pressure becomes smaller.

Next, examples and experimental examples will be explained.

< example 4>

A first pipe having a first outer diameter and a first inner diameter and a second pipe having a second outer diameter and a second inner diameter larger than the first outer diameter are prepared, the length of a pressurization part is 30% of the length of a main body in a central axis direction, a closed sleeve having a pressure step difference of 5% of the second outer diameter is manufactured, the closed sleeve is connected to the first pipe, and the first pipe is inserted into the second pipe, thereby realizing insertion coupling and sealing of the first pipe and the second pipe.

< example 5>

Insertion bonding and sealing of the hermetically sealed sleeve and the first and second tubes were achieved in the same manner as in example 4, except that the pressure step difference was formed to be 10% of the second outer diameter.

< example 6>

Insertion bonding and sealing of the hermetically sealed sleeve and the first and second tubes were achieved in the same manner as in example 4, except that the pressure step difference was formed to be 15% of the second outer diameter.

< comparative example 3>

The insertion bonding and sealing of the hermetically sealed sleeve and the first and second tubes were achieved in the same manner as in example 1, except that the length of the pressurizing portion was set to 3% of the length in the central axis direction of the main body.

< comparative example 4>

The insertion bonding and sealing of the hermetically sealed sleeve and the first and second tubes were achieved in the same manner as in example 1, except that the length of the pressurizing portion was 20 times the length in the central axis direction of the main body.

< Experimental example 2>

In the state where the sealed type sleeves of example 4, example 5, example 6, comparative example 3, and comparative example 4 and the first and second pipes were connected, the sealed type sleeves and the first and second pipes were sealed by inserting and joining them with a hydraulic jig, and after sealing, refrigerant was supplied to the line pipes and the state of the sealed type sleeves was observed. The results are shown in Table 2.

[ Table 2]

As shown in the results of table 2, the first tube and the second tube sealed by the hermetically sealed sleeves of examples 4 to 6 of the present invention did not crack or leak the refrigerant fluid. However, in the case of comparative example 3, a fluid leakage phenomenon occurs, and in the case of comparative example 4, a cross-sectional fracture phenomenon of the sealed sleeve occurs during sealing.

The pressurizing part includes a front-end pressurizing part and a rear-end pressurizing part (defined as the front-end pressurizing part being closer to the inlet part than the rear-end pressurizing part), and an inner diameter of the front-end pressurizing part, which is an inner diameter of the front-end pressurizing part, may be larger than an inner diameter of the rear-end pressurizing part, which is an inner diameter of the rear-end pressurizing part. Preferably, both the rear end pressing portion and the front end pressing portion are formed in a flat shape. When the closed type pressurizing portion is provided with the pressurizing portion composed of the front end pressurizing portion and the rear end pressurizing portion, the contact between the outer surface of the second tube and the front end pressurizing portion is not released when the end of the second tube enters the rear end pressurizing portion through the front end pressurizing portion during the mounting process, because the second tube is plastically deformed, the outer diameter of the rear end pressurizing portion becomes smaller than that of the front end pressurizing portion, and the pair of front end pressurizing portion and rear end pressurizing portion of the second tube maintains the overall contact.

In view of this, the difference between the inner diameter of the front end pressurizing part and the inner diameter of the rear end pressurizing part may be set to be 1 to 10% of the inner diameter of the rear end pressurizing part. If the difference between the inner diameter of the front end pressurizing part and the inner diameter of the rear end pressurizing part is larger than 10% of the inner diameter of the rear end pressurizing part, the possibility that the contact between the outer surface of the second pipe and the front end pressurizing part is released becomes large, or the amount of impact applied to the sealed type sleeve during the installation becomes large, and if the difference between the inner diameter of the front end pressurizing part and the inner diameter of the rear end pressurizing part is smaller than 1% of the inner diameter of the rear end pressurizing part, the advantage of the pressurizing part structure of the two-stage structure will disappear.

The main body according to an embodiment of the present invention has a recognition structure that can recognize the directions of the inlet and outlet by touch. With the identification structure, the operator can easily identify the direction of the sealed casing even when the operator is free-handed or wearing gloves.

The identification structure can be formed relative to a positive carving structure protruding relatively or a negative carving structure sinking relatively outside the main body, and the positive carving structure or the negative carving structure can have a step difference of 0.2-2 mm relative to the surface of the main body. If the step difference of the identification structure with respect to the outer surface of the main body is less than 0.2mm, it is difficult to identify the identification structure in a state where the worker is working with gloves, and if the step difference is more than 2mm, it is disadvantageous in terms of cost. In addition, the length of the recognition structure in the longitudinal direction is not limited.

The identification structure is preferably mounted on one of the inlet portion and the outlet portion in a concentrated manner without being restricted in position by the inlet portion or the outlet portion. At the same time, the tip of the identification feature need not be aligned with an inlet or outlet side end surface.

Next, a method of using the sealed type bushing according to the embodiment of the present invention will be described.

First, the sealed sleeve is inserted into the first tube so that the inlet is close to the insertion joint. Second, the first tube is inserted into the second tube with the hermetically sealed sleeve inserted. And thirdly, inserting the end of the second pipe end into the inlet side of the closed sleeve. Fourth, as pressure is applied to the outlet portion side end portion of the sealed type sleeve, the second pipe is inserted along the curved surface of the pressurization introduction portion, and the tip end of the second pipe end portion reaches the pressurization portion first boundary portion. Fifth, the tip of the second pipe end reaches the second boundary of the pressurization part as the pressure is applied to the outlet-part-side end of the sealed sleeve. Sixthly, the pressurizing part applies sealing pressure to the insertion joint part to complete the mutual sealing connection of the first pipe and the second pipe. Of course, the method of use is not limited by the above examples.

The above-described embodiments are intended to be illustrative only and not limiting, and it will be appreciated by those of ordinary skill in the art that changes, modifications, and equivalents may be made. But rather should be construed to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. For example, the individual components may be dispersed and the dispersed components may be combined.

The scope of the present invention is defined only by the appended claims, which are not limited to the above detailed description, and all changes and modifications derived from the meaning and scope of the claims and equivalents are included in the scope of the present invention.