WO2017179811A1

WO2017179811A1 - Method for preparing sealing sleeve

Info

Publication number: WO2017179811A1
Application number: PCT/KR2017/001842
Authority: WO
Inventors: 배창환; 전용진; 이종철; 황권웅
Original assignee: (주)하나테크
Priority date: 2016-04-12
Filing date: 2017-02-20
Publication date: 2017-10-19
Also published as: KR101684858B1; CN107530779B; CN107530779A

Abstract

An embodiment of the present invention, in a method for preparing a sealing sleeve, comprises: a preparation step for preparing a metal powder body comprising a molding lubricant and metal powder comprising iron; a molding step for charging the metal powder body into a mold, applying pressure to the metal powder body and thus molding same into a green compact; a sintering step for sintering the green compact and thus forming a sintered compact; a fixing step for applying pressure to the inner side of the sintered compact, forming a predetermined curvature with respect to the inside diameter of a housing, and preparing a fixed compact; an impregnating step for resin-impregnating the fixed compact and thus sealing the micropores of the fixed compact; and a plating step for plating the fixed compact for which resin-impregnation has been performed and thus completing a sealing sleeve.

Description

Manufacturing method of hermetic sleeve

The present invention relates to a method for manufacturing an airtight sleeve for a domestic, industrial, commercial, and automotive air conditioning system and a refrigeration / refrigeration system to which a refrigerant pipe is applied. More specifically, the present invention relates to a powder using a metal powder containing iron powder. The present invention relates to a method of manufacturing a hermetic sleeve by performing molding, sintering, shaping and plating by a metallurgical process.

For home, industrial, commercial, and automotive air conditioning systems (air conditioners) and home, industrial, and commercial refrigeration / freezing systems (refrigerators, freezers, etc.), refrigerants that are charged with high pressure are used. The joints should be tightly sealed, and a hermetic sleeve is used as a component for such a sealing connection.

The hermetic sleeve is important not only for the fastening mechanism for connecting the two tubes, but also for its material and manufacturing process. In terms of materials, corrosion resistance, chemical resistance, rigidity, surface strength, and the like are required, and in terms of manufacturing process, high dimensional accuracy and internal diameter roughness management are required in processing the inner diameter of the hermetic sleeve.

In Korean Patent Laid-Open Publication No. 1997-0073775 (name of the invention: a method for manufacturing a metal pipe, hereinafter referred to as the prior art 1), the work of leveling a flat plate of a raw material of metal is performed and bending both sides of the metal plate by rolling. (Forming) forming process, the method of increasing the curvature gradually to approach the cross section in the direction perpendicular to the tube axis in a circle, the welding process is welded along the seam line in the next process, and then welded cutting process Disclosed is a method of manufacturing a metal pipe comprising a shaping step of quenching (water cooling) and measuring the same, a calibrating step of correcting the warpage of the pipe by a calibrator, and a cutting step of cutting a saw, grindstone, or tip according to the application. have.

In addition, a technique of applying cutting (machining) in order to increase the dimensional accuracy in the inner diameter processing of the sleeve in the shaping process has been disclosed in the related art (hereinafter referred to as the prior art 2).

In the case of the sheet metal forming method of the prior art 1, in order to make the pipe formed in the longitudinal direction to the desired length, it is necessary to be accompanied by a device necessary for cutting, not only to weld the welds, but also to manage the inner diameter roughness of the pipe There were problems such as not being able to.

In addition, as in the prior art 2, when the inner diameter machining of the sleeve is performed by using cutting machining, the roughness of the inner diameter surface cannot be managed well, and the friction caused by friction in the process of mounting the sleeve to the pipe. Problems such as breakage or leakage of fluid occur during use after installation.

In order to achieve the above technical problem, one embodiment of the present invention in the manufacturing method of the hermetic sleeve for sealingly coupling two tubes having through-holes and different sizes, comprising a metal powder and a molding lubricant containing iron A preparation step of preparing a metal powder to form, a molding step of putting the metal powder into a mold and applying pressure to form a green compact, a sintering step of sintering the green compact to form a sintered compact, by applying pressure to the inner wall of the through hole of the sintered compact In the shaping step of manufacturing a shaped body through a shaping process so that the cross-section of the through hole has a predetermined profile, the impregnating step of sealing the pores of the shaped body by impregnating the shaped body, the shaped body subjected to resin impregnation It provides a method of manufacturing a hermetic sleeve comprising a plating step of performing a plating to complete a hermetic sleeve.

In addition, the molding lubricant may be characterized by including 0.2 to 1.5 wt% with respect to the total weight of the metal powder.

In addition, an embodiment of the present invention is a method of manufacturing a hermetic sleeve, the metal powder, copper (Cu) 8wt% or less, nickel (Ni) 5wt% or less, molybdenum (Mo) 2wt% with respect to the total metal powder weight Hereinafter, the composition may be composed of 5 wt% or less of chromium (Cr), 1.5 wt% or less of carbon (graphite), and balance iron (Fe).

In addition, an embodiment of the present invention, in the manufacturing method of the hermetic sleeve, may be characterized in that it further comprises a polishing step and a rust prevention step between the sintering step and the shaping step.

In addition, an embodiment of the present invention, in the method of manufacturing a hermetic sleeve, may be characterized in that the plating is performed after impregnating and curing the resin to fill the pores of the product, before performing the plating step.

In addition, an embodiment of the present invention, in the manufacturing method of the hermetic sleeve, the pressure in the forming step may be characterized in that it is carried out at a pressure of 2 to 10 Ton / cm ² .

In addition, an embodiment of the present invention, in the method of manufacturing a hermetic sleeve, the sintering step may be characterized in that it is carried out at the sintering temperature of 1000 to 1300 ℃.

In addition, an embodiment of the present invention, in the method of manufacturing a hermetic sleeve, the sintering step may be characterized in that it is carried out for 20 to 120 minutes at the sintering temperature.

In addition, an embodiment of the present invention, in the method of manufacturing a hermetic sleeve, the sintering step may be characterized in that it is carried out in an atmosphere of 5 to 75 wt% hydrogen and 25 to 95wt% nitrogen.

In addition, an embodiment of the present invention, in the manufacturing method of the hermetic sleeve, the shaping step may be characterized in that it is carried out at a pressure of 1 to 10 Ton / cm ² .

In addition, an embodiment of the present invention is a method of manufacturing a hermetic sleeve, the impregnation step is a vacuum impregnation step for performing a vacuum impregnation of the molded body in a vacuum state, and curing the molded body at 70 to 200 ℃ for the molded body It may be characterized by including a curing step to perform.

In addition, an embodiment of the present invention is a method of manufacturing a hermetic sleeve, the impregnation step is a dipping step for filling the resin impregnation solution in the pores by dipping the crystals in the resin impregnation liquid with respect to the molded body 70 to 200 It may be characterized in that it comprises a curing step of performing the curing at ℃.

In addition, an embodiment of the present invention may further include a vacuum impregnation step of impregnating a shaped body in a vacuum state between a dipping step and a curing step in the manufacturing method of the hermetic sleeve.

In addition, an embodiment of the present invention is a method of manufacturing a hermetic sleeve, the plating step is characterized in that the plating with one or two or more alloys selected from the group consisting of zinc, nickel and chromium to prevent corrosion of the hermetic sleeve. You can do

According to an embodiment of the present invention, the powder metallurgy process using metal powder has the first effect that the surface roughness is superior to the processed product and has high dimensional accuracy, and the processing cost is lowered because the machining is not performed. Internal effect roughness management can be performed precisely through the shaping process using the second effect, press core, which can be applied to various types of pipes, can increase the tightening force when knuckle (fastening), and improve the sealing reliability Can provide a fourth effect.

The effects of the present invention are not limited to the above-described effects, but should be understood to include all the effects deduced from the configuration of the invention described in the detailed description or claims of the present invention.

1 is a flow chart of a manufacturing method of a hermetic sleeve according to an embodiment of the present invention.

Figure 2 is a graph showing the change in the apparent density of the hermetic sleeve according to the mixing time of the metal powder according to an embodiment of the manufacturing method of the hermetic sleeve of the present invention.

Figure 3 is a schematic diagram showing the shape of the sleeve manufactured according to an embodiment of the manufacturing method of the hermetic sleeve of the present invention.

Figure 4 is a schematic diagram showing an axial cross-sectional view of a sleeve manufactured according to an embodiment of the manufacturing method of the hermetic sleeve of the present invention.

One preferred embodiment of the present invention is as follows.

The first tube and the second tube are mutually inserted to seal the first tube having the first outer diameter and the first inner diameter and the second tube having the second outer diameter and the second inner diameter larger than the first outer diameter. In the hermetic sleeve installed in the insertion coupling portion in the state,

A pillar-shaped main body having a main axis;

In the manufacturing method of the hermetic sleeve for sealing the two pipes of different sizes, the main body through-hole on the main body,

i) preparing a metal powder including iron and a metal powder comprising a molding lubricant;

ii) molding the metal powder into a mold and applying pressure to form the green compact;

iii) sintering the green compact to form a sintered body;

iv) forming a shaped body through a shaping process by applying pressure to an inner wall of the through hole of the sintered body so that the cross section of the through hole has a predetermined profile;

v) an impregnation step of sealing the pores of the form by impregnating the resin; And

vi) a plating step of performing a plating on the resin-impregnated body to complete the hermetic sleeve; and

The hermetic sleeve may be formed in a state in which the first tube having the first outer diameter and the first inner diameter and the second tube having the second outer diameter and the second inner diameter larger than the first outer diameter, which are two tubes having different sizes, are inserted into each other. The first pipe and the second pipe has a shape for being installed in the insertion coupling region which is the contact area,

In the shaping step, the through-hole is installed in the insertion coupling portion, the internal diameter value is gradually increased in the longitudinal direction of the hermetic sleeve in order to increase the clamping force and sealability by increasing the pressure during the mounting process on the insertion coupling portion or Method for producing a hermetic sleeve, characterized in that it is formed to have a gradient to be small.

Hereinafter, with reference to the accompanying drawings will be described the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to be "connected (connected, contacted, coupled)" with another part, it is not only "directly connected" but also "indirectly connected" with another member in between. "Includes the case. In addition, when a part is said to "include" a certain component, this means that it may further include other components, without excluding the other components unless otherwise stated.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. As used herein, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof described on the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

The hermetic sleeve manufactured by the present invention comprises 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 tube having a second inner diameter larger than the first outer diameter. The second pipe has a shape so as to be installed in the insertion coupling portion in the state inserted into each other. The insertion coupling portion indicates a portion and an adjacent region where the first tube and the second tube are coupled to and contacted. In the embodiment shown in FIG. 3 or FIG. 4, a hermetic sleeve with a through hole is shown in a generally cylindrical shape. The through hole is a structure for mounting on the insertion coupling portion, and in order to increase the pressure in the mounting process, the through hole may have a predetermined cross-sectional profile such that the inner diameter value is gradually increased while going from the inlet to the outlet.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In this document, the metal powder is to refer to the object to be loaded into the mold for forming the green compact, the metal powder is formed by adding a molding lubricant to the metal powder. A metal powder shall refer to the powder-like material which contains metals, such as copper, nickel, molybdenum, and chromium, graphite (carbon), etc. based on iron. In the metal powder, copper, nickel, molybdenum, chromium, or the like may be included as an alloy material of iron, or may be present in a powder form independently of the iron powder. In addition, some of copper, nickel, molybdenum and chromium may be present in an alloy phase of iron, and the remainder may be prepared by mixing with an iron alloy powder as a powder. Some of copper, nickel, chromium and molybdenum may be excluded from the composition of the metal powder.

According to one embodiment of the present invention, a method of manufacturing a hermetic sleeve includes preparing a metal powder containing iron and a metal powder comprising a molding lubricant, and putting the metal powder into a mold and applying pressure to the green compact. A shaping step of forming, a sintering step of sintering the green compact to form a sintered body, and a shaping step of manufacturing a shaped body through a shaping process of applying a pressure to an inner wall of the through hole of the sintered body so that the cross section of the through hole has a predetermined profile; It may include an impregnation step of sealing the pores of the molded body by impregnating the molded body, a plating step of performing a plating on the molded body subjected to the resin impregnation to complete the hermetic sleeve.

In addition, an embodiment of the present invention may further include a polishing step and a rust prevention step between the sintering step and the shaping step in the manufacturing method of the hermetic sleeve.

In the preparation step of the metal powder, the molding lubricant may include 0.2 to 1.5 wt% with respect to the total metal powder weight.

In addition, by applying the molding lubricant, the apparent density of the entire metal powder may be increased. As an example of the molding lubricant, zinc stearate, Kenolube, or amide wax may be applied. Preferably, zinc stearate or Kenolube may be applied. Referring to FIG. 2, it can be seen that when zinc stearate or Kenolube is used as the molding lubricant, the apparent density of the metal powder is superior to that of using amide wax as the molding lubricant.

Molding lubricant is a friction with the mold surface when the metal powder in the mold is compressed during molding, this may generate heat and scratch on the mold surface, it can be used to prevent this. However, if it exceeds 1.5 wt%, the compressibility decreases and burn-our during sintering may appear as a defect in the sintered body, and when used below 0.2wt%, it may cause heat generation and scratch on the mold surface. May be unsuitable for

The metal powder is the metal powder, excluding the molding lubricant, and based on the total metal powder weight, copper (Cu) 8 wt% or less, nickel (Ni) 5 wt% or less, molybdenum (Mo) 2 wt% or less, and chromium (Cr) 5 wt% Up to%, up to 1.5 wt% of carbon (graphite) and the balance iron (Fe).

Iron may be a powder prepared by a reduction method or a spraying method, and copper powder may be a powder prepared by a spraying method or an electrolysis method. In addition, the nickel, molybdenum and chromium powders may be alloyed with iron or used by mixing nickel, molybdenum and chromium powders.

Copper serves to increase the ductility and strength of the product at the same time, if the amount of more than 8wt% is deformed during sintering can be lowered the precision of the dimension can be unsuitable for use.

Nickel, molybdenum and chromium powders can serve to enhance the strength of the product. If the nickel powder exceeds 5wt%, the strength of the product is increased but the toughness is lowered, which may cause a problem of brittleness. If the molybdenum is more than 2wt%, the strength is increased but the toughness is reduced, the brittleness is increased. It can cause problems. In addition, even if the chromium powder exceeds 5wt%, the strength of the product is improved but toughness may be unsuitable for use.

Carbon (graphite) reacts with iron during sintering to improve strength, but when it exceeds 1.5 wt%, a problem of sharp embrittlement may occur by generating a structure called cementite in the metal structure.

Physical properties of the required metal powder (metal powder) include apparent density, flowability, and compressibility.

The apparent density is the density in the powder state before forming the green compact, whereby the green compact density is affected. In the present invention, it is proposed to make 2 to 4 g / cm ³ as the apparent density of the metal powder. Apparent density 2 g / cm ³ If less, the green compact density is low, which causes a problem that the density of the final product may also be low.

Flow is a property related to the molding precision, regardless of whether the metal powder moves well to the corner of the mold when the metal powder is charged into the mold.

In the molding step, after forming the green compact, the process of confirming a burr above and below the green compact may be further sprayed to remove air. In addition, the pressure in the molding step may be carried out at a pressure of 2 to 10 Ton / cm ² . If the pressure is less than ² Ton / cm ^2, the compaction density of the green compact may be insufficient, resulting in insufficient strength of the final product.

The sintering step may be performed at 1000 to 1300 ° C. for 20 to 120 minutes. If the sintering temperature is less than 1000 ℃ sintering temperature is too low may not be sintering properly, if the sintering temperature is higher than 1300 ℃, the sintering temperature is too high, the amount of dimensional sintering of the sintered body has a large amount of dimensional deformation is deteriorated, energy efficiency is poor It may not be suitable for use. In addition, if the sintering speed is less than 20 minutes, sintering does not occur sufficiently may be unsuitable in terms of strength, and if it exceeds 120 minutes, the strength is increased but the sintering deformation is not suitable in that the dimensional accuracy is poor. Consider.

In addition, the sintering step may be carried out in an atmosphere of 5 to 75 wt% hydrogen and 25 to 95wt% nitrogen. Such mixed gas may be referred to as AX gas. AX gas is a gas produced by decomposing ammonia, and is composed of nitrogen and hydrogen. It is also possible to use nitrogen further. It may consist of 5 to 75% hydrogen and 25 to 95% nitrogen. Hydrogen reduces the oxide on the metal surface in the sintering step and allows diffusion bonding between metals, and nitrogen serves as an inert gas to prevent oxidation of the sintered body.

After finishing the sintering step, the polishing step may be performed. The polishing step may perform a barrel process, and may remove burrs of the sintered body generated during the sintering process. Preferably, a rotary barrel can be used. Of course, the barrel method using equipment other than a rotary barrel is not excluded.

After finishing the polishing step, the lubricating step may be performed. The lubrication step is to immerse the sintered body in the rusted oil so that the rusted oil exists in the surface and pores of the sintered body to reduce the friction between the product and the mold and act as a lubrication when forming the next process. You can also play a role of rust prevention.

The shaping step may be a process of correcting warpage, dimensions, or shape of the sintered body, and in particular, correcting the shape and dimensions of the inner diameter portion of the sintered body, so that the cross-section of the through hole may have a predetermined profile. The inside of the through hole may have the same inner diameter in the longitudinal direction as shown in FIG. 3 or 4, but in order to increase the fastening pressure, a gradient is obtained in which the inner diameter value gradually increases or decreases when viewed in the longitudinal direction. You can have it.

The sintered compact is mounted on the mold of the press and the product is pressed with a punch. At this time, a shape of the inner diameter can be formed by the core formed in the mold. The press pressure of the shaping step may be performed at 1 to 10 Ton / cm ² . Unlike the shaping process through the shaping process as described above, the inner roughness (surface state) can be made good, and because of the good inner roughness, it can be applied to various kinds of pipes, It is possible to increase the sealing reliability.

There may be a washing and drying step between the shaping step and the impregnation step. In the washing step, it may be desirable to work with the hydrocarbon-based washing liquid, but this does not exclude other methods. The drying step may be carried out in a vacuum atmosphere at a temperature of 80 to 130 ℃.

The impregnation step is to fill the fine pores present in the body with respect to the body body. The impregnation step may include a dipping step, a washing step, and a curing step for the body body.

First, the dipping step of the impregnation step may be a step of dipping a fixed body having pores in the resin impregnation liquid and inducing resin impregnation using air. In addition, the vacuum impregnation step may be further performed after the dipping step, and the process may be performed by omitting the dipping step according to conditions of use and requirements. The resin impregnation liquid may be an organic impregnation agent, but is not limited thereto.

There may be a washing step and a curing step of proceeding washing and curing of the resin-impregnated form. The curing step may be to perform curing at 70 to 200 ℃. If it is less than 70 ℃ hardening may not be made properly, if it exceeds 200 ℃ may not be efficient in terms of process efficiency and may be unsuitable for carrying out the process because of the high energy consumption.

The plating step may plate one or two or more alloys selected from the group consisting of zinc, nickel and chromium to prevent corrosion of the hermetic sleeve. Of course, the plating of metals to prevent corrosion other than zinc is not excluded.

Hereinafter, the effects of the present invention will be described in detail through examples and experimental examples of the present invention. The examples presented are merely illustrative of the invention and are not intended to limit the scope of the invention. According to one embodiment of the present invention, the sleeve manufacturing method may form a predetermined profile on the inner wall of the through hole, and the forming process of the inner wall of the metal powder and the through hole in the shaping step according to the requirements of use, manufacturing needs, and mounting requirements. This can be determined.

Example 1

Metal powders containing 96.4 wt% reduced pure iron powder, 2 wt% copper powder, 0.8 wt% graphite powder and 0.8 wt% zinc stearate were prepared, and the results of measuring the apparent density and flowability of the metal powder are shown in Table 1. .

Apparent density, g/cm³ Apparent density, g / cm ³	Flow, sec/50gFlow, sec / 50g
2.652.65	2929

The apparent density of the metal powder was 2.65 g / cm ³ and the flowability was ^{29 s} / 50 g, which corresponds to a range in which a precise green compact shape and density can be obtained in green compact forming.

In addition, the compressibility of the green compact measured according to the compression pressure is shown in Table 2.

Compacting pressureCompacting pressure	Compressibility, g/cm³(0.8% Zn-st)Compressibility, g / cm ³ (0.8% Zn-st)
300 MPa(21.6 tsi)300 MPa (21.6 tsi)	6.356.35
500 MPa(36.0 tsi)500 MPa (36.0 tsi)	6.916.91
700 MPa(50.4 tsi)700 MPa (50.4 tsi)	7.167.16

This compression density was confirmed to be a value within the range required to satisfy the specifications (strength, rigidity) of the final product.

Metal powder was laminated and a green compact was prepared by applying a pressure of 3 Ton / cm ² using a pressing machine (model name: CP-5). Then, the uniformity of the density was confirmed with respect to the molded green compact and the presence of cracks or surface defects was confirmed.

The measurement results of the green strength of the green compact according to the pressurized pressure are shown in Table 3.

Compacting pressureCompacting pressure	Green strength, MPa(10³psi) (0.8% Zn-st)Green strength, MPa (10 ³ psi) (0.8% Zn-st)
300 MPa(21.6 tsi)300 MPa (21.6 tsi)	7(1.0)7 (1.0)
500 MPa(36.0 tsi)500 MPa (36.0 tsi)	13(1.9)13 (1.9)
700 MPa(50.4 tsi)700 MPa (50.4 tsi)	17(2.5)17 (2.5)

Sintering was performed at a temperature of 1120 ° C. on the green compact from which the burr was removed. After sintering, the sintering was performed for 10 minutes with a rotary barrel, and then dipping was performed for 2 minutes using a rust preventive.

A shaping process for enhancing the dimensional accuracy by shaping the inner diameter of the through-hole by the defined profile was performed using the pressing machine. The green compact and the core were placed in the mold of the press machine, and the pressure was applied.

The washed body was washed and dried with a hydrocarbon-based washing solution, and an automatic vacuum ultrasonic washing dryer was used. After drying, the resin was impregnated into the molded body, and a resin impregnation solution (IP1000) was used. It was dipped in the resin impregnation solution (IP1000) for 10 minutes.

After the resin impregnation, washing and curing were performed, and a sealed sleeve was manufactured by galvanizing.

The foregoing description of the present invention is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is represented by the following claims, and it should be construed that all changes or modifications derived from the meaning and scope of the claims and their equivalents are included in the scope of the present invention.

10: sleeve

Claims

In the method of manufacturing a hermetic sleeve for sealing two pipes of different sizes having a through hole,

i) preparing a metal powder including iron and a metal powder comprising a molding lubricant;

ii) molding the metal powder into a mold and applying pressure to form the green compact;

iii) sintering the green compact to form a sintered body;

iv) forming a shaped body through a shaping process by applying pressure to an inner wall of the through hole of the sintered body so that the cross section of the through hole has a predetermined profile;

v) an impregnation step of sealing the pores of the form by impregnating the resin;

vi) a plating step of performing plating on the resin-impregnated body to complete the hermetic sleeve;

Method of manufacturing a hermetic sleeve comprising a.
The method according to claim 1,

The molding lubricant in step i) is 0.2 to 1.5 wt% of the total weight of the metal powder, characterized in that the manufacturing method of the closed sleeve.
The method according to claim 2,

The metal powder in step i), copper (Cu) 8wt% or less, nickel (Ni) 5wt% or less, molybdenum (Mo) 2wt%, chromium (Cr) 5wt% or less, based on the total metal powder weight (Graphite) A manufacturing method of a hermetic sleeve, characterized in that it is composed of 1.5 wt% or less and the balance iron (Fe).
The method according to claim 1,

The method of manufacturing a hermetic sleeve further comprising a polishing step and a rust prevention step between the sintering step and the shaping step.
The method according to claim 1,

Pressure in the forming step is a manufacturing method of the closed sleeve, characterized in that carried out at a pressure of 2 to 10 Ton / cm 2 .
The method according to claim 1,

The sintering step is a manufacturing method of the hermetic sleeve, characterized in that carried out at the sintering temperature of 1000 to 1300 ℃.
The method according to claim 1,

The sintering step is a manufacturing method of the hermetic sleeve, characterized in that carried out for 20 to 120 minutes at the sintering temperature.
The method according to claim 1,

The sintering step is a manufacturing method of the hermetic sleeve, characterized in that carried out in an atmosphere of 5 to 75 wt% hydrogen and 25 to 95wt% nitrogen.
The method according to claim 1,

The shaping step is a manufacturing method of the hermetic sleeve, characterized in that carried out at a pressure of 1 to 10 Ton / cm 2 .
The method according to claim 1,

The impregnating step may include a vacuum impregnation step for performing vacuum impregnation of the form body with respect to the form body, and a curing step of performing curing of the form body at 70 to 200 ° C. Manufacturing method.
The method according to claim 1,

The impregnation step includes a dipping step of filling the resin impregnation solution in the pores by dipping the form into a resin impregnation solution and a curing step of curing the form at 70 to 200 ° C. Method for producing a hermetic sleeve characterized in that.
The method according to claim 11,

And a vacuum impregnation step of impregnating the shaped body in a vacuum state between the dipping step and the hardening step.
The method according to claim 1,

The plating step is a method of manufacturing a hermetic sleeve, characterized in that the plating with one or two or more alloys selected from the group consisting of zinc, nickel and chromium to prevent corrosion of the hermetic sleeve.