KR100554348B1 - Methode for measuring suction pressure of reaction gas in core and measurement using the same - Google Patents

Abstract

The present invention is made of a structure in which the core can be drawn in and the internal and external segregation is possible, and a pressure gauge for measuring the internal pressure, and a part of the wall surface is opened if the internal vacuum degree is greater than or equal to the size selected by the user. The chamber comprising a solenoid valve for sealing the wall if the degree of vacuum is less than the size selected by the user; Suction means for discharging air inside the chamber to the outside of the chamber and discharging air inside the core to the outside of the chamber; A measuring means comprising a back pressure sensor configured to be in close contact with the surface of the core or inserted into the middle of the core to measure suction pressure generated inside the core, and a sensor holder for mounting the back pressure sensor; It comprises a recorder for recording the suction pressure measured by the measuring means, the reaction gas inside the core that can measure the suction pressure generated in each part of the core according to the change in the suction pressure magnitude and the suction position of the reaction gas Provide a suction pressure measuring device.

Core, casting, reaction gas, suction pressure, measurement, sensor

Description

Method for measuring suction pressure of reaction gas in core and measurement using the same}

1 is a flow chart of the method for measuring the inside pressure of the reaction gas inside the core according to the present invention.

2 is a perspective view of the middle gas inside reaction gas suction pressure measuring apparatus according to the present invention.

3A to 3C are a perspective view, a front view, a side view, and a rear view, respectively, of a shape in which measuring means are mounted in a chamber applied to the present invention.

4 illustrates a shape in which a back pressure sensor is coupled to a core used when manufacturing a water jacket.

5A to 5E illustrate changes in suction pressure inside the core according to a change in a junction point and a reaction gas suction point between the upper and lower cores.

<Description of the symbols for the main parts of the drawings>

100: chamber 110: opening and closing door

112: clamp 120: chamber inlet

130: middle suction port 140: sensor connector

150: pressure gauge 160: solenoid valve

200 suction means 210 first suction hose

220: second suction hose 230: third suction hose

240: dust collector 250: vacuum pump

300: measuring means 310: back pressure sensor

320: sensor cradle 400: recorder

500: Computer 600: Middle

610: the bottom plate core 620: the top plate core

The present invention relates to a measuring method for measuring the pressure to suck the reaction gas in order to discharge the reaction gas ejected from the molten metal during the casting process and a measuring device for measuring the reaction gas suction pressure.

When casting a metal product, a large amount of reaction gas containing harmful components such as carbon monoxide, carbon dioxide, methane, phenol, etc. is generated by the reaction between the molten metal and the core material. When such a reaction gas flows into the mold, the molten metal hardens. As the chemical reaction between the reaction gas and the melt occurs, not only the solidification of the melt does not work normally, but also the defective parts are generated because the melt is not normally filled in the area where the gas is located.

In order to solve such a problem, a device for inhaling the reaction gas and discharging it to the outside has been devised and commercialized. At this time, the pressure for sucking the reaction gas has not been designed based on accurate experimental data, but has been mainly set by experience. The position at which the reaction gas is sucked is also arbitrarily selected by the manufacturer.

In the case where the core has a simple shape, even if the suction pressure or the suction position of the reaction gas is arbitrarily selected, the reaction gas is smoothly discharged, so that product shape defects do not occur. However, when the shape of the core is fine and complicated, the reaction gas is not completely discharged when the suction pressure becomes too low, and when the suction pressure is excessively high, the molten metal is hardened to an abnormal shape by being affected by the suction pressure. There is a problem that you lose. In addition, in the case where the shape of the core is complicated, there is a difficulty in selecting the reaction gas suction position accurately so that a constant suction pressure is generated at each portion of the core.

Therefore, the manufacturer should accurately determine the suction pressure or suction position of the reaction gas based on the experimental data, and measure the magnitude of suction pressure generated in each part according to the suction pressure magnitude and the change in suction position of the reaction gas. Since there is no equipment to perform, there is a problem that data for calculating the suction pressure and the suction position cannot be obtained.

The present invention has been made in order to solve the above problems, by calculating the suction pressure and suction position of the reaction gas by measuring the suction pressure generated in each part of the core according to the change in the suction pressure size and the suction position of the reaction gas. An object of the present invention is to provide a method and apparatus for measuring a reaction gas suction pressure inside a core capable of obtaining data.

In order to achieve the above object, the method for measuring the reaction gas suction pressure inside the core according to the present invention includes: a first step of placing the core in a chamber; A second step of continuously discharging air inside the chamber to form a degree of vacuum in the chamber; A third step of discharging air inside the core to the outside of the chamber; A fourth step of measuring a suction pressure generated at one or more inner core points selected by a user's selection; And a fifth step of recording the pressure value measured in the fourth step.

The second step includes the step 2-1 of measuring the degree of vacuum in the chamber; And a step 2-2 of opening a part of the chamber when the vacuum degree inside the chamber is greater than or equal to the size selected by the user, and closing the chamber when the vacuum degree inside the chamber is less than the size selected by the user.

In the third step, the pressure for discharging air inside the core to the outside of the chamber is set to be greater than the pressure for discharging air inside the chamber. At this time, the pressure to discharge the air inside the core to the outside of the chamber is 10 to 30 mbar, the pressure to discharge the air inside the chamber is preferably set to 30 to 70 mbar.

In addition, it is preferable that a plurality of points for sucking air inside the core in the third step are selected.

Reaction gas suction pressure measuring apparatus inside the middle of the core according to the present invention, the chamber can be drawn in and the internal and external structure is configured to be separated; Suction means for discharging air inside the chamber to the outside of the chamber and discharging air inside the core to the outside of the chamber; Measuring means which is introduced into the chamber and measures the suction pressure inside the core; And a recorder for recording the suction pressure measured by the measuring means.

The chamber includes a pressure gauge for measuring the pressure inside the chamber; When the degree of vacuum inside the chamber is larger than the size selected by the user, a part of the chamber is opened, and when the degree of vacuum inside the chamber is less than the size selected by the user is configured to include a solenoid valve.

The measuring means comprises: a back pressure sensor configured to have a measuring portion in close contact with the surface of the core or inserted into the middle of the core to measure suction pressure generated inside the middle of the core; It is configured to include a sensor holder for mounting the back pressure sensor.

In addition, the chamber is provided with an opening / closing door having a size capable of drawing in and out of the core on one side wall, and the chamber suction port, the core suction port, and the sensor connector are formed on the rear wall. At this time, the suction means, the first suction hose one end is coupled to the chamber suction port, the second suction hose one end is coupled to the core seated inside the chamber through the middle suction port, the first suction hose and the second suction hose It is configured to include a vacuum pump connected to the other end of the suction hose to generate the suction pressure.

In addition, the chamber is formed in a box shape with an empty inside to enable the seating of the core, the suction hose coupling port is formed on one side, the seating table is formed on the upper side is formed with one or more suction ports on the site where the core is seated It is provided on the side; The suction means further includes a third suction hose, one end of which is coupled to the suction hose coupler, and the vacuum pump is connected to the other end of the third suction hose to generate the suction pressure.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the reaction gas suction pressure measuring method and measuring apparatus inside the core according to the present invention.

1 is a flow chart of the method for measuring the inside pressure of the reaction gas inside the core according to the present invention.

As shown in FIG. 1, the method for measuring the middle gas inside reaction gas suction pressure according to the present invention includes a core inside a chamber equipped with a first suction hose for air suction inside the chamber and a second suction hose for air suction inside the core. After positioning the first step (S10) for coupling the back pressure sensor and the second suction hose to the core for measuring the pressure change inside the core; A second step (S20) of forming a vacuum degree of a predetermined size inside the chamber by continuously discharging the air in the chamber to the outside by driving the vacuum pump connected to the first suction hose; A third step (S30) of discharging air inside the core to the outside of the chamber by driving a vacuum pump connected to the second suction hose; A fourth step (S40) of applying an operation signal to the back pressure sensor to measure the suction pressure generated at the inner point of the core to which the back pressure sensor is coupled; And a fifth step (S50) for recording the suction pressure value measured by the back pressure sensor in the fourth step (S40).

In addition, the second step (S0), the step 2-1 to measure the degree of vacuum in the chamber; And a step 2-2 of opening a part of the chamber when the vacuum degree inside the chamber is greater than or equal to the size selected by the user, and closing the chamber when the vacuum degree inside the chamber is less than the size selected by the user. Therefore, air is introduced into the chamber from the outside as much as the air inside the chamber exits to the outside of the chamber, so that the degree of vacuum in the chamber is maintained.

In addition, in the third step, the pressure for sucking the air inside the core is set to be greater than the pressure for discharging the air inside the chamber to the outside of the chamber, so that the reaction gas generated inside the core is the pressure for sucking the air inside the core and the inside of the chamber. The air is discharged out of the chamber through the second suction hose to a size equal to the pressure difference that discharges the air out of the chamber. At this time, since the core is formed by hardening after making the sand into a predetermined shape, when the core vacuum pressure exceeds 70 mbar, the shape of the core may be broken.

Therefore, the core vacuum pressure for discharging air inside the chamber is set to 30 to 70 mbar, and the chamber vacuum pressure for discharging air inside the core to the outside of the chamber is preferably set to 30 mbar or less.

In addition, it is preferable that a plurality of points for sucking air inside the core in the third step are selected.

Figure 2 is a perspective view of the middle gas inside reaction gas suction pressure measuring apparatus according to the present invention.

As shown in Figure 2, the reaction gas suction pressure measuring apparatus inside the core according to the present invention, the core can be drawn in and formed in a box shape that can be separated from the inside and outside, the introduction and withdrawal of the core on one side wall The chamber is formed in a possible size is provided with the opening and closing door 110 is configured to be locked by the clamp 112, the chamber suction port 120, the middle suction port 130 and the sensor connector 140 is formed on the rear wall 100; A first suction hose 210 having one end coupled to the chamber suction opening 120 and one side to discharge the air inside the chamber 100 to the outside of the chamber and to discharge the air inside the core to the outside of the chamber 100, and one side of the chamber 100. A second suction hose 220, the end of which penetrates the middle suction port 130 and is coupled to the middle seat seated inside the chamber 100, a third suction hose 230 connected to the bottom of the core, and each suction hose ( Suction means 200 including a dust collecting cylinder 240 coupled to the other end of the 210 ~ 230 to filter dust and various foreign matter, and a vacuum pump 250 coupled to the dust collecting cylinder 240 to generate a suction pressure and; Measuring means 300 including a back pressure sensor 310 introduced into the chamber 100 and coupled to a part of the core, and a sensor mounting base 320 for mounting the back pressure sensor 310; A recorder 400 connected to the back pressure sensor 310 through the sensor connector 140 to record and record the suction pressure measured by the back pressure sensor 310; And a computer 500 for storing data output from the recorder 400.

In the present embodiment, the second suction hose 220 and the third suction hose 230 are combined into one and connected to the vacuum pump 250, but the second suction hose 220 and the third suction hose 230 are respectively separately. It may be configured to be connected to the vacuum pump 250. At this time, the outside of the chamber 100 through the first pressure control valve 212, the second suction hose 220 and the third suction hose 230 for adjusting the suction pressure through the first suction hose 210. Preferably, the second pressure control valve 222 for adjusting the suction pressure is further provided.

In addition, when the recorder 400 is provided with a function of data storage, the recorder 400 and the computer 500 may be integrated into one.

The chamber 100 includes a pressure gauge 150 for measuring a pressure inside the chamber 100; The solenoid valve for opening a part of the chamber 100 when the vacuum degree inside the chamber 100 is greater than or equal to the size selected by the user, and sealing the chamber 100 when the vacuum degree inside the chamber 100 is less than the size selected by the user ( 160).

When the driving of the vacuum pump 250 continues, a vacuum degree is formed in the chamber 100. When it is determined that the vacuum degree formed in the chamber 100 by the pressure gauge 150 is formed to a predetermined size or more, the solenoid valve In order to reduce the degree of vacuum inside the chamber 100, the air outside the chamber 100 is opened to draw into the chamber 100. At this time, in order to prevent the vacuum degree inside the chamber 100 from being lost, the solenoid valve 160 is closed to block the inside and the outside of the chamber 100 when the vacuum degree inside the chamber 100 is lowered to a predetermined size or less. . Therefore, the vacuum degree inside the chamber 100 is constantly maintained by the pressure gauge 150 and the solenoid valve 160.

When the air in the chamber 100 is sucked through the first suction hose 210 and a vacuum pressure of a predetermined size is formed in the chamber 100, even if the air inside the core is sucked, the abnormal flow is inside the chamber 100. Since the steady state is not generated, the user can more accurately measure the suction pressure generated inside the core.

In addition, when a vacuum pressure of a predetermined size is formed in the chamber 100, a suction pressure of a vacuum pressure magnitude is applied to the middle element seated inside the chamber 100, so that the second suction hose 220 is applied. In case of inhaling the air inside the core, the pressure of the air sucked through the second suction hose 220 is substantially equal to the difference between the suction pressure of the second suction hose 220 and the suction pressure of the first suction hose 210. Will have the size of. Therefore, when the air inside the core is to be sucked through the second suction hose 220, the suction pressure of the second suction hose 220 must be greater than the suction pressure of the first suction hose 210.

At this time, the core 600 may be damaged if the pressure applied to a part is repeatedly changed. Therefore, when the user wants to experiment while changing the air suction pressure inside the core, the user may suck the air inside the core. The suction pressure of the suction hose 220 is kept constant and the suction pressure of the first suction hose 210 which sucks the air in the chamber 100 is preferably changed and the experiment is performed.

3A to 3C are a perspective view, a front view, a side view, and a rear view, respectively, of a shape in which measuring means are mounted in a chamber applied to the present invention.

As shown in Figure 3a to 3c the chamber 100 is applied to the present invention, the seating surface 170 for seating the middle of the core is provided on the bottom surface, the shape of the middle is seated inside the second suction hose It is preferable that the shape 220 is coupled to the core, and the mounting shape and position of the back pressure sensor 310 may be made of a transparent material so that it can be seen from the outside.

The seating unit 170 is formed in a box shape having an empty inside, and a suction hose coupler 172 which is coupled to the end of the third suction hose 230 is formed at one side thereof, and the middle is seated at the upper side. One or more inlets 174 are formed in the site.

The reaction gas generated inside the core is discharged to the outside through the third suction hose 230 through the suction port 174 and the suction hose coupler 172.

4 illustrates a shape in which a back pressure sensor is coupled to a core used when manufacturing a water jacket.

As shown in FIG. 4, the core 600 used in manufacturing the water jacket is formed in a plate shape having a length in left and right directions, and irregularities are formed in accordance with the shape of the water jacket, and the reaction gas is sucked in the longitudinal direction at the left and right ends. Lower plate core 610 is provided with a lower plate suction portion 612 for, and formed in the shape that can be seated on the upper surface of the lower plate core 610, the upper plate for sucking the reaction gas therein in a direction perpendicular to the longitudinal direction at one end The upper plate core 620 is provided with a suction unit 622.

A plurality of coupling protrusions 614 and a connection portion 616 are formed on the upper side of the lower plate core 610, and the coupling protrusions are formed on the lower side of the upper plate core 620 of the portion corresponding to the coupling protrusion 614. Coupling groove 624 is formed to be recessed so that a portion of the end of the 614 is drawn.

In the present embodiment, six coupling protrusions 614 and six coupling grooves 624 are formed, and two connecting portions 616 are formed, so that the upper plate core 620 is seated on the upper surface of the lower plate core 610. The core 620 and the lower plate core 610 are in contact with a total of eight places. At this time, since the core 600 is made of mold sand, even if a separate exhaust passage is not formed, the reaction gas flow is possible between the mold sand particles, and when contacted with another core, the contact portion is contacted. Internal reaction gas is delivered. Therefore, when the reaction gas suction pressure is applied to the upper plate suction unit 622, the reaction gas formed in the lower plate core 610 moves to the upper plate core 620 through the coupling protrusion 614 and the connection unit 616 to absorb the upper plate. When the reaction gas suction pressure is applied to the lower plate suction unit 612, the reaction gas formed inside the upper plate core 620 may be coupled to the coupling protrusion 614 and the connection unit 616. By moving to the lower plate core 610 through it can be discharged to the outside through the lower plate suction portion 612.

In addition, the core 600 is formed with a concave groove-shaped sensor engaging holes 626A to 626E to be coupled to the back pressure sensor 310. In this embodiment, a total of five sensor coupling holes 626A to 626E are formed at equal intervals on the top plate core 620, and the formation position and number of the sensor coupling holes 626A to 626E can be freely changed according to a user's selection. Can be.

5A to 5E illustrate changes in suction pressure inside the core according to a change in a junction point and a reaction gas suction point between the upper and lower cores.

The upper plate core 620 and the lower plate core 610 are bonded to one or more coupling protrusions 614 and coupling grooves 624 so that the mutual coupling position is not changed during the injection of the molten metal. Since the reaction gas is not moved to the portion to be bonded, the adhesive coating point is preferably set to a minimum within the limit that the coupling of the upper plate core 620 and the lower plate core 610 is not released.

FIG. 5A is a graph showing experimental results showing the magnitude of the reaction gas suction pressure generated in each of the sensor coupling holes 626A to 626E as the suction time is sucked only through the upper plate suction unit 622.

At this time, each graph shown in Figure 5a is a graph showing the magnitude of the reaction gas suction pressure generated in each sensor coupling port (626A ~ 626E) of the upper plate suction portion 622, the closer to the upper plate suction portion 622 It can be seen that a large reaction gas suction pressure is generated.

In this case, when the reaction gas is sucked only into the upper plate suction unit 622, it can be seen that a non-uniform reaction gas suction pressure is generated at each part of the sensor coupling holes 626A to 626E at the beginning of the reaction gas suction.

Figure 5b shows the magnitude of the reaction gas suction pressure generated in each sensor coupling as the suction time when the adhesive is applied to the coupling protrusions and coupling grooves of six places and the suction gas is sucked into the upper plate suction part and the lower plate suction part. The experimental results graph.

When the reaction gas is sucked into the upper plate suction part 622 and the lower plate suction part 612 at the same time, the suction pressure is simultaneously applied to each of the sensor coupling holes 626A to 626E in the up, down, left and right directions, as shown in FIG. 5B. The reaction gas suction pressure generated in each of the sensor coupling holes 626A to 626E forms a uniform size than when the reaction gas is sucked only through the upper plate suction part 622.

Figure 5c shows the magnitude of the reaction gas suction pressure generated in each sensor coupling as the suction time when the adhesive is applied to the three coupling protrusions and the coupling groove and the suction gas to the upper plate suction portion and the lower plate suction portion The experimental results graph.

When the adhesive is applied only to the three coupling protrusions 614 and the coupling grooves 624 among the six coupling protrusions 614 and the coupling grooves 624, the remaining three coupling protrusions 614 to which the adhesive is not applied. And since the reaction gas can be moved through the coupling groove 624, when the adhesive is applied to the three coupling protrusions 614 and the coupling groove 624, six coupling protrusions (as shown in Figure 5c ( 614 and a reaction gas suction pressure greater than that of applying the adhesive to the coupling groove 624 is formed.

Figure 5d is applied to the adhesive projections and coupling grooves of the six places and when the suction of the reaction gas to the suction port of the upper plate suction unit 622 and the lower plate suction unit and the seating, generated in each sensor coupling port as the suction time elapsed It is a graph of experimental results showing the magnitude of the reaction gas suction pressure.

When the reaction gas is sucked into not only the upper plate suction part 622 and the lower plate suction part 612 but also the suction port 174 of the seating table 170, the reaction gas is provided only by the upper plate suction part 622 and the lower plate suction part 612. The reaction gas suction pressure is formed larger than that of suction (see FIG. 5B).

At this time, as the reaction gas suction pressure direction is also added to the bottom direction, the reaction gas suction pressure generated in each of the sensor coupling holes 626A to 626E is formed to have a more uniform size.

FIG. 5E shows a reaction gas inhalation generated in each sensor coupling hole as the suction time passes when the adhesive is applied to the three coupling protrusions and the coupling grooves and the suction gas is sucked into the upper plate suction unit, the lower plate suction unit, and the seating inlet. It is a graph of experimental results showing the magnitude of pressure.

Even if the reaction gas suction point is additionally selected, when the adhesive is applied to the three coupling protrusions 614 and the coupling groove 624, the six coupling protrusions 614 and the coupling groove 624 are illustrated in FIG. 5E. ), The reaction gas suction pressure is greater than that of the adhesive (see FIG. 5D).

As such, when the reaction gas suction pressure measuring device inside the core according to the present invention is used, it is possible to repeat the experiment by changing the reaction gas suction position and the measurement position, and thus find the most suitable reaction gas suction point according to the shape of the core. There is an advantage that it can.

As mentioned above, although this invention was demonstrated in detail using the preferable embodiment, the scope of the present invention is not limited to a specific embodiment and should be interpreted by the attached claim. In addition, those skilled in the art should understand that many modifications and variations are possible without departing from the scope of the present invention.

By using the reaction gas suction pressure measuring method and measuring device inside the core according to the present invention, the suction pressure generated in each part of the core according to the change in the suction pressure magnitude and the suction position of the reaction gas, the reaction gas It is an advantage that accurate data for calculating suction pressure and suction position can be obtained.

Claims (10)

Placing the core 600 in the chamber 100 (S10); A second step (S20) of forming a vacuum pressure having a predetermined size in the chamber 100 by continuously inhaling air in the chamber 100 and discharging it to the outside of the chamber 100; A third step (S30) of sucking the air inside the core 600 and discharging it to the outside of the chamber 100; A fourth step (S40) of measuring suction pressure generated at one or more inner points of the core 600 selected by the user's selection; A fifth step (S50) of recording the magnitude of the suction pressure measured in the fourth step (S40); Reaction gas suction pressure measurement method of the middle (600) inside, characterized in that comprising a. The method of claim 1, The second step (S20), Step 2-1 of measuring the vacuum pressure inside the chamber (100); When the vacuum pressure inside the chamber 100 is greater than or equal to the size selected by the user, a part of the chamber 100 is opened. When the vacuum pressure inside the chamber 100 is less than the size selected by the user, the chamber 100 is opened. Step 2-2 to seal the; Reaction gas suction pressure measurement method of the middle (600) inside, characterized in that comprising a. The method according to claim 1 or 2, In the third step (S30), the vacuum pressure to suck the air inside the core 600, Reaction gas suction pressure measurement method of the inside of the core (600), characterized in that it is set larger than the vacuum pressure to suck the air in the chamber (100). The method of claim 3, wherein The vacuum pressure to suck the air inside the core 600 is 30 to 70 mbar, Reaction gas suction pressure measuring method of the inside of the core 600, characterized in that the vacuum pressure for sucking the air in the chamber 100 is 30 mbar or less. The method according to claim 1 or 2, In the third step (S30) the point of sucking the air inside the core 600, Reaction gas intake pressure measurement method of the inside of the core 600, characterized in that a plurality selected. A chamber 100 capable of retracting the core 600 and configured of an internal and external isolation structure; The air in the chamber 100 is sucked and discharged to the outside of the chamber 100 to form a vacuum pressure inside the chamber 100, and the air inside the core 600 is sucked out of the chamber 100. Suction means for discharging to 200; Measuring means (300) drawn into the chamber (100) to measure suction pressure inside the core (600); A recorder 400 for recording the suction pressure measured by the measuring means 300; Reaction gas suction pressure measuring device of the inside of the middle character 600, characterized in that comprises a. The method of claim 6, The chamber 100, A pressure gauge 150 for measuring internal pressure; A solenoid valve 160 which opens a part of the wall surface when the internal vacuum pressure is greater than or equal to the size selected by the user, and seals the wall surface when the internal vacuum pressure is less than the size selected by the user; Reaction gas suction pressure measuring device of the inside of the middle character 600, characterized in that comprises a. The method according to claim 6 or 7, The measuring means 300, A back pressure sensor 310 configured to be in close contact with the surface of the core 600 or inserted into the core 600 so as to measure suction pressure generated inside the core 600; A sensor cradle 320 for mounting the back pressure sensor 310; Reaction gas suction pressure measuring device of the inside of the middle character 600, characterized in that comprises a. The method according to claim 6 or 7, The chamber 100, An opening and closing door 110 having a size capable of drawing in and out of the core 600 on one side wall, and a chamber suction port 120, a middle suction port 130, and a sensor connector 140 formed on the rear wall; The suction means 200, A first suction hose 210 having one end coupled to the chamber suction port 120 and a second suction hose 220 having one end coupled to the core 600 seated inside the chamber by passing through the middle suction port 130. And a vacuum pump 250 connected to the other ends of the first suction hose 210 and the second suction hose 220 to generate suction pressure. Gas suction pressure measuring device. The method according to claim 6 or 7, The chamber 100, The core 600 may be seated and formed in a box shape with an empty inside, and a suction hose coupler 172 may be formed at one side thereof, and at least one suction hole at a portion contacting the core 600 at an upper side thereof. 174 is provided with a seating surface 170 is formed on the bottom surface; The suction means 200, One end is further provided with a third suction hose 230 is coupled to the suction hose coupler 172; The vacuum pump 250, Reaction gas suction pressure measuring device inside the jungja 600, characterized in that configured to generate a suction pressure is connected to the other end of the third suction hose (230).

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