JP2003039159A - Supplying device for molten metal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a molten metal intruding in a valve box and a supplying path to be easily discharged in a molten metal furnace in drawing up a supplying device from the molten metal furnace while enabling a molten metal having less possibility of entraining a metallic oxide to be sucked in a cylinder case, with simple construction. SOLUTION: A suction path 22 is penetrally formed on the valve box 19 so as to open on a valve body transfer space 24 at the higher position than that of a discharge path 23, and a fitting part 32, for internally fitting freely inserting/pulling out a supplying path forming member 30 formed with a supplying path 2 into a base material 29 provided with a cylinder case 4, is formed. The discharge path is communicated with the inside of the fitting part, and the discharge path is provided so as to communicate with the supplying path in the state that the supplying path forming member is internally fitted. And on the bottom part of the fitting part, a communication path 33, capable of communicating with the molten metal furnace D at the position lower than that of the discharge path, is penetrably formed, and a closing member 36 capable of closing the communication path accompanying internally fitting the supplying path forming member against the fitting part, is provided integrally with the supplying path forming member.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for connecting a molten metal suction / exhaust passage to the inside of a cylinder case, and moving a piston in the cylinder case to one side so that the molten metal in a molten metal furnace is passed through the suction / exhaust passage. Provided is a molten metal pump that can be sucked into the cylinder case and that can discharge the molten metal in the cylinder case through the suction / discharge passage by moving the piston to the other side, and cast the molten metal discharged through the suction / discharge passage. A suction passage communicating with the melt furnace, a discharge passage communicating with the supply passage, and a suction suction passage extending into the valve body moving space; A suction position that communicates with the suction / discharge path to block communication between the discharge path and the suction / discharge path;
A switching valve equipped with a valve body that can be moved up and down at a discharge position that connects the discharge passage to the suction and discharge passages and blocks the communication between the suction passage and the suction and discharge passages. Is provided so as to open into the metal melt of the melt furnace, and the metal melt in the melt furnace is moved to one of the pistons while the valve body is moved to the suction position. A metal configured to discharge the molten metal in the cylinder case to the supply path by an operation of moving the piston to the other while the valve body is sucked in and the valve body is moved to the discharge position. The present invention relates to a molten metal supply device.

[0002]

2. Description of the Related Art In a conventional apparatus for supplying molten metal, a suction passage communicating with a melting furnace is formed through the bottom of a valve box, and a suction port of the suction passage opens into the molten metal near the bottom of the melting furnace. Is provided.

[0003]

Therefore, there is a problem that it is easy to suck the molten metal mixed with the metallic oxide accumulated at the bottom of the melting furnace into the cylinder case, and such metallic oxide is mixed. In order to allow the molten metal to be sucked into the cylinder case with a low risk, in order to provide the suction port of the suction passage so that it opens into the molten metal at a high position in the melting furnace, the pipe for sucking the molten metal should be used as the suction passage. There is a drawback that the structure becomes complicated because it is necessary to connect separately and to provide the inlet of the pipeline as a suction port at a high position in the melt furnace.

Further, if a pipe for sucking molten metal is separately connected to the suction passage and the inlet of the pipe is provided at a high position in the melting furnace as a suction port, the feeder is used for maintenance and inspection. When pulled up from the furnace, there is also a drawback that it is difficult to discharge the molten metal that has entered the valve box or the supply passage into the molten metal furnace.

The present invention has been made in view of the above-mentioned circumstances, and has a simple structure so that a metal melt which is less likely to be mixed with a metal oxide can be sucked into a cylinder case and a supply device is used to melt the metal melt. An object of the present invention is to enable the molten metal which has entered the valve box or the supply passage to be easily discharged into the molten metal furnace when the metal molten metal is pulled up from the furnace.

[0006]

According to the characterizing feature of the invention described in claim 1, in the molten metal furnace, the suction and discharge passage of the molten metal is communicated with the inside of the cylinder case, and the piston in the cylinder case is moved to one side. Is provided with a molten metal pump capable of sucking the molten metal in the cylinder case through the suction and discharge passages and discharging the molten metal in the cylinder case through the suction and discharge passages by moving the piston to the other side. A supply path for supplying the molten metal discharged through the path to the casting apparatus is provided, and an intake path communicating with the melt furnace, an exhaust path communicating with the supply path, and an intake / exhaust path are opened in the valve body moving space. In the valve box, there is a suction position in which the suction passage communicates with the suction and discharge passage to block the communication between the discharge passage and the suction and discharge passage, and the suction passage communicates with the suction and discharge passage. A switching valve provided with a valve body that can be operated to move up and down at a discharge position that cuts off the communication between the passage and the suction and discharge passage, so that the suction port of the suction passage opens in the molten metal of the melting furnace. When the valve body is moved to one of the pistons while the valve body is moved to the suction position, the molten metal in the melting furnace is sucked into the cylinder case and the valve body is moved to the discharge position. A molten metal supply device configured to discharge the molten metal in the cylinder case to the supply path by a moving operation of the piston to the other side in a moved state, wherein the suction path is A supply path forming member having the supply path formed on a base material which is formed through the valve box and has the cylinder case so as to open to the valve body moving space at a position higher than the discharge path. Fitting part that fits in and out freely from above The discharge passage is formed to communicate with the inside of the fitting portion, and the discharge passage is provided to communicate with the supply passage in a state where the supply passage forming member is fitted inside the fitting portion, At the bottom of the fitting part,
A communication passage that can communicate with the molten metal furnace is formed at a position lower than the discharge passage, and the communication passage can be closed as the supply passage forming member is fitted into the fitting portion. The member is provided integrally with the supply path forming member.

[Operation] Since the suction passage is formed through the valve box so as to open in the valve body moving space at a position higher than the discharge passage, the pipe for sucking the molten metal is sucked in as in the conventional case. It is possible to provide the suction port of the suction passage so as to open into the molten metal at a high position in the molten metal furnace without separately connecting to the passage.

Then, a fitting portion is formed on the base material provided with the cylinder case so that the supply passage forming member having the supply passage can be inserted and removed from above, and the discharge passage is provided inside the fitting portion. Since the discharge passage is provided so as to communicate with the supply passage in a state where the supply passage forming member is fitted in the fitting portion, when the supply device is pulled up from the melting furnace, the supply passage forming member is By pulling out upward from the fitting part, the molten metal that has entered the supply passage formed in the supply passage forming member can be discharged into the melt furnace, and the inside of the valve box communicates with the melt furnace through the discharge passage. Then, the metal melt that has entered the valve box can be discharged into the melt furnace through the discharge passage.

Further, a communication passage that can communicate with the molten metal furnace is formed through the bottom portion of the fitting portion at a position lower than the discharge passage, and the supply passage forming member is fitted in the fitting portion. Since the closing member that can close the communication passage is provided integrally with the supply passage forming member, by pulling the supply passage forming member upward from the fitting portion, the closing of the communication passage is released, and the fitting portion is released. When the cylinder case is pulled up from the molten metal furnace and the bottom portion of the metal plate is communicated with the molten metal furnace through the communication passage, there is little possibility that the molten metal will remain in the fitting portion.

[Effect] With a simple structure in which the intake passage is formed through the valve box so as to open in the valve body moving space at a position higher than the discharge passage, there is little possibility that metal oxides are mixed. When pulling up the supply device from the melting furnace while allowing the molten metal to be drawn into the cylinder case,
It is possible to easily discharge the molten metal that has entered the valve box or the supply passage into the molten metal furnace.

According to a second aspect of the present invention, the suction and discharge passage of the molten metal is communicated with the cylinder case, and the piston in the cylinder case is moved to one side to suck and discharge the molten metal in the melting furnace. A metal pump capable of being sucked into the cylinder case through a passage and discharging the metal melt in the cylinder case through the suction and discharge passages by moving the piston to the other side, and the metal discharged through the suction and discharge passages. A supply path for supplying molten metal to the casting apparatus is provided, and a suction path communicating with the melt furnace, a discharge path communicating with the supply path, and a valve box having the suction and discharge path opened in the valve body moving space, An intake position that communicates the suction passage with the suction passage to block the communication between the discharge passage and the suction passage, and a suction position that communicates the discharge passage with the suction passage through the suction passage and the suction passage. A switching valve provided with a valve body that can be moved up and down freely at a discharge position that shuts off the communication of the valve body so that the suction port of the suction passage opens into the molten metal of the melting furnace. When the piston is moved to one of the pistons in the suction position, the molten metal in the melting furnace is sucked into the cylinder case, and the valve body is moved to the discharge position. A molten metal supply device configured to discharge the molten metal in the cylinder case to the supply path by moving the piston to the other side, wherein the suction path is higher than the discharge path. A fitting portion is formed through the valve box so as to open into the valve body moving space at a position, and a base member provided with the cylinder case is formed with a fitting portion into which the valve box can be inserted and removed from above. , Connecting the supply passage to the inside of the fitting part And so that the supply passage communicates with the discharge passage in a state where the valve box is fitted in the fitting portion, and the molten metal furnace is provided at a position lower than the supply passage at a bottom portion of the fitting portion. And a closing member capable of closing the communication passage when the valve housing is fitted in the fitting portion. It is in.

[Operation] Since the suction passage is formed so as to penetrate through the valve box so as to open in the valve body moving space at a position higher than the discharge passage, the pipe for sucking the molten metal is sucked as in the conventional case. It is possible to provide the suction port of the suction passage so as to open into the molten metal at a high position in the molten metal furnace without separately connecting to the passage.

A fitting portion is formed on a base material provided with a cylinder case so that the valve box can be inserted and removed from above, and the supply path is communicated with the inside of the fitting section to fit the valve box. Since the supply passage is provided so as to communicate with the discharge passage in the state of being fitted in the joint part, when pulling up the supply device from the molten metal furnace, by pulling out the valve casing from the fitting portion, The molten metal entering inside can be discharged into the melting furnace through the discharge passage, and the supply passage communicates with the inside of the melting furnace at the fitting part, and the molten metal entering inside the supply passage is discharged into the melting furnace. be able to.

Further, a communication passage is formed through the bottom of the fitting portion so as to be able to communicate with the molten metal furnace at a position lower than the supply passage, and as the valve box is fitted into the fitting portion, the communication passage is formed. Since the closing member that can close the valve box is provided integrally with the valve box, by pulling the valve box upward from the fitting portion, the closing of the communication passage is released, and the bottom portion of the fitting portion passes through the communication passage. When communicating with the melting furnace and pulling up the cylinder case from the melting furnace,
There is little risk of molten metal remaining in the fitting part.

[Effect] With a simple structure in which the intake passage is formed through the valve box so as to open in the valve body moving space at a position higher than the discharge passage, it is less likely that metal oxide is mixed. When pulling up the supply device from the melting furnace while allowing the molten metal to be drawn into the cylinder case,
It is possible to easily discharge the molten metal that has entered the valve box or the supply passage into the molten metal furnace.

According to a third aspect of the present invention, the communication passage is formed so as to vertically penetrate along the insertion / extraction direction of the supply passage forming member or the valve box, and the supply passage forming member or the valve box is formed. There is a point that the closing member is provided so as to be fitted into the communication passage as it is fitted into the fitting portion.

[Operation] By the operation of fitting the supply passage forming member or the valve box into the fitting portion from above, the closing member is also fitted into the communication passage and the opening thereof is closed. By the operation of pulling the valve box upward from the fitting portion, the closing member is also pulled out from the communication passage and the closing is released.

[Effect] The operation of inserting and removing the supply passage forming member or the valve box in the up and down direction with respect to the fitting portion can be easily performed.
The communication passage can be closed or released.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. [First Embodiment] FIG. 1 shows a supply device A for supplying a molten metal C of a magnesium alloy as an example of a molten metal to a casting device B. The molten metal pump 1 and the molten metal C are supplied to a mold B1 of the casting device B. And a switching valve 3 for switching the flow path between a state in which the molten metal C in the molten metal furnace D can be sucked into the molten metal pump 1 and a state in which the molten metal C sucked into the molten metal pump 1 can be discharged into the supply channel 2. And the molten metal C discharged from the molten metal pump 1
Can be supplied to the mold B1 through the supply path 2.

The molten metal pump 1 is formed integrally with a cylinder case 4 made of ceramic (silicon nitride), a piston 5 made of ceramic (silicon nitride) reciprocally movable up and down in the cylinder case 4, and a piston 5. And a pneumatic cylinder 7 for driving a piston for vertically reciprocating a piston rod 6 provided therein. The suction / discharge passage 8 for the molten metal C is communicated with the cylinder case 4 near the bottom thereof, and the piston 5 is moved upward to move the molten metal. The molten metal C in the furnace D can be sucked into the cylinder case 4 through the suction / discharge passage 8, and the molten metal C in the cylinder case 4 can be discharged through the suction / discharge passage 8 by moving the piston 5 downward.

In the cylinder case 4, the lower opening of the cylinder chamber forming through hole 10 formed in the ceramic case body 9 is closed by a ceramic lid plate 11 to form a cylinder chamber 12, and the furnace of the melting furnace D is used. The base plate 14 detachably fixed to the lid 13 and the outer peripheral side of the case body 9 are connected by a connecting arm 15 made of ceramic (silicon nitride), and the entire cylinder case 4 is filled with the molten metal C in the melting furnace D. A support table 17 which is fixed so as to be submerged in the molten metal C at a position lower than the range of elevation of the liquid level and supports the pneumatic cylinder 7 for piston drive and the pneumatic cylinder 16 for valve operation, is a column 18.
It is fixed to the base plate 14 with.

As shown in FIG. 2, the switching valve 3 has a valve box 19 formed in the case body 9 so that the entire valve box 19 is lower than the liquid level elevation range of the molten metal C in the molten metal furnace D. A ceramic (silicon nitride) valve body 21 which is provided below the liquid surface and integrally formed with a valve rod 20 is mounted on the valve box 19 so as to be vertically movable, and communicates with the melt furnace D. The suction passage 22, the discharge passage 23 communicating with the supply passage 2, and the suction and discharge passage 8
And are formed so as to open in the valve body moving space 24.

In the valve body moving space 24, as shown in FIG. 2, a cylindrical valve body mounting hole 25 into which the valve body 21 can be inserted / removed is formed in the case body 9, and an upper portion of the valve body mounting hole 25 is formed. The sleeve 26 can be inserted in and removed from the inner peripheral surface so that it can be inserted and fixed.
It is formed in the valve body mounting hole portion below the sleeve 26.

The discharge passage 23 is formed at the lower end of the valve body moving space 24 so as to open upward, and a suction through hole 27 extending between the case body 9 and the sleeve 26 is formed so that the discharge passage 23 is higher than the discharge passage 23. A suction passage 22 that opens downward at the upper end of the valve body moving space 24, which is the position, is formed by the suction through hole 27 and the inside of the sleeve 26, and the suction port of the suction passage 22 is opened in the molten metal of the melting furnace D. In addition, the valve rod 20 is provided with a closing member 28 that closes the gap between the valve rod 20 and the sleeve 26 while sliding on the inner surface of the sleeve 26.

The discharge passage 23 is formed in a discharge passage forming member (an example of a base material) 29 made of ceramic (silicon nitride) and fixed to the case body 9 by bolts so as to open at the bottom of the valve body moving space 24. And a cylindrical supply pipe made of ceramic (an example of the supply passage forming member) provided in the discharge passage forming member 29.
30 is connected to connect the supply passage 2 to the discharge passage 23, and the supply pipe 30 is covered with a heat-resistant heat insulating material 31 over substantially the entire length thereof.

As shown in FIG. 2A, the valve body 21 has an intake position where the intake passage 22 communicates with the intake / exhaust passage 8 to block the communication between the exhaust passage 23 and the intake / exhaust passage 8, and FIG. As shown in (b), the discharge path 23 is connected to the suction / discharge path 8 so as to be vertically movable at a discharge position where the suction path 22 and the suction / discharge path 8 are blocked from each other. As shown, valve body 2
1 is moved to the suction position, the operation of moving the piston 5 upward causes the molten metal C in the molten metal furnace D to move to the cylinder case 4.
2B, the molten metal C in the cylinder case 4 is supplied to the supply path 2 by the downward movement operation of the piston 5 with the valve body 21 moved to the discharge position, as shown in FIG. It is configured to discharge.

As shown in FIG. 3, the discharge path forming member 29.
A circular fitting hole (an example of a fitting portion) 32 is formed on the inner surface of the supply pipe 30 so that the supply pipe 30 can be inserted and removed from above in a positioned state, and the discharge path 23 is provided inside the fitting hole 32. In addition to communicating with each other, a fitting hole 32 is formed so as to vertically penetrate along the insertion / extraction direction of the supply pipe 30, and a communication path that can communicate with the molten metal furnace D at a position lower than the discharge path 23 at the bottom of the fitting portion 32. 33
Has been formed.

A ceramic (silicon nitride) pipe end closing member 34 for closing the lower end of the supply pipe 30 is integrally formed, and a through hole 35 is formed in a pipe wall near the pipe end closing member 34 to form a supply pipe. The discharge passage 23 is provided so as to communicate with the supply passage 2 in a state in which 30 is fitted in the fitting hole 32.

The lower end 36 of the supply pipe is connected to the supply pipe 30.
Is fitted into the fitting hole 32, is fitted into the communication passage 33, and is integrally provided in the supply pipe 30 as a closing member capable of closing the communication passage 33.

[Second Embodiment] FIG. 4 shows another embodiment of a supply device A for supplying a molten metal C of a magnesium alloy to a casting device B as an example of a molten metal, and the supply device shown in the first embodiment. Portions different from A will be described.

As shown in FIGS. 5 and 6, the switching valve 3 is provided so that it can be inserted into and removed from the case body 9 from above, and a discharge passage 23 communicating with the supply passage 2 and an intake and discharge passage 8 are provided in the valve body moving space. 24
A suction passage 22 communicating with the molten metal furnace D is formed through the valve box 19 opened at the lower part of the above so as to open at the upper part of the valve body moving space 24 which is higher than the discharge passage 23.

A circular fitting hole (an example of a fitting portion) 38 is formed in the base material 37 extending from the lower part of the case body 9 so that the valve box 19 can be inserted and removed from above in a positioned state. Then, the midway of the suction / discharge path 8 is communicated with the inside of the fitting hole 38, and the supply path forming member 39 made of ceramic (silicon nitride) is bolted to the base material 37 to fix the supply path 2 to the fitting hole 38. The suction / discharge passage 8 communicates with the cylinder chamber 12 and the valve body moving space 24, and the supply passage 2 discharges with the valve box 19 fitted in the fitting hole 38 in a positioned state. It is provided so as to communicate with the passage 23.

At the bottom of the fitting hole 38, a communication passage 40 that can communicate with the molten metal furnace D at a position lower than the supply passage 2 is provided.
Are formed so as to vertically penetrate along the insertion / extraction direction of the valve box, and are fitted into the communication passage 40 at the lower end of the valve box 19 as the valve box 19 is fitted into the fitting hole 38. A closing member 42 capable of closing 40 is provided in a protruding manner. Other configurations are similar to those of the first embodiment.

[Other Embodiments] 1. In the apparatus for supplying molten metal according to the present invention, a communication passage capable of communicating with the melting furnace may be laterally formed at the bottom of the fitting portion. 2. The apparatus for supplying molten metal according to the present invention may supply the molten metal to a ladle provided in the casting apparatus. 3. The apparatus for supplying a molten metal according to the present invention may supply a molten metal such as aluminum, zinc or tin.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional side view of an apparatus for supplying molten metal.

FIG. 2 is a partial cross-sectional side view of a main part.

3A is a perspective view of a main part, and FIG. 3B is a partial cross-sectional side view of the main part.

FIG. 4 is a partial cross-sectional side view of a molten metal supply apparatus showing a second embodiment.

FIG. 5 is a partial cross-sectional side view of a main part showing the second embodiment.

FIG. 6 is a partial cross-sectional side view of a main part showing a second embodiment.

[Explanation of symbols] 1 molten metal pump 2 supply paths 3 switching valve 4 cylinder case 5 pistons 8 suction and discharge 19 valve box 21 valve 22 Inhalation route 23 discharge path 24 Valve body moving space 29 Base material 30 supply path forming member 32 Fitting part 33 passages 36 Blocking member 37 Base material 38 Fitting part 40 passages 41 Blocking member B casting equipment C molten metal D Melting furnace

Continued front page    (72) Inventor Hiroshi Yamaguchi             2-47 Shikitsuhigashi, Naniwa-ku, Osaka-shi, Osaka               Kubota Corporation

Claims (3)

[Claims] 1. A metal melt suction / exhaust passage is communicated with the cylinder case, and a piston in the cylinder case is moved to one side, whereby the metal melt in the melting furnace can be sucked into the cylinder case through the suction / discharge passage. And a supply path for supplying the molten metal discharged through the suction / discharge passage to the casting apparatus by providing a molten metal pump capable of discharging the molten metal in the cylinder case through the suction / discharge passage by moving the piston to the other side. An intake passage communicating with the melt furnace, a discharge passage communicating with the supply passage, and an intake / exhaust passage communicating with the valve box having the valve body moving space opened, and the intake passage communicating with the intake / exhaust passage. And a suction position that blocks communication between the discharge passage and the suction and discharge passage, and a discharge position that communicates the discharge passage with the suction and discharge passage and blocks communication between the suction passage and the suction and discharge passage. A switching valve equipped with a valve body that can be freely moved downward is provided so that the suction port of the suction passage opens into the molten metal of the melting furnace, and the valve body is moved to the suction position. In the operation of moving the piston to one of the pistons, the molten metal in the melting furnace is sucked into the cylinder case, and the operation of moving the piston to the other while moving the valve body to the discharge position is performed. A molten metal supply device configured to discharge the molten metal in the cylinder case to the supply passage, wherein the suction passage is opened to the valve body moving space at a position higher than the discharge passage. As described above, a fitting portion that is formed so as to penetrate through the valve box and that has the cylinder case is provided with a fitting portion that internally fits the supply passage forming member that forms the supply passage from above. , The discharge passage communicates with the inside of the fitting part With the supply passage forming member fitted in the fitting portion, the discharge passage is provided so as to communicate with the supply passage, and the bottom portion of the fitting portion is provided at a position lower than the discharge passage. A communication passage that can communicate with the melt furnace is formed so as to penetrate therethrough, and a closing member that can close the communication passage when the supply passage forming member is fitted into the fitting portion is provided in the supply passage forming member. A device for supplying molten metal, which is integrally provided in the. 2. A metal melt suction / exhaust passage is communicated with the cylinder case, and a piston in the cylinder case is moved to one side so that the metal melt in the melt furnace can be sucked into the cylinder case through the suction / discharge passage. And a supply path for supplying the molten metal discharged through the suction / discharge passage to the casting apparatus by providing a molten metal pump capable of discharging the molten metal in the cylinder case through the suction / discharge passage by moving the piston to the other side. An intake passage communicating with the melt furnace, a discharge passage communicating with the supply passage, and an intake / exhaust passage communicating with the valve box having the valve body moving space opened, and the intake passage communicating with the intake / exhaust passage. And a suction position that blocks communication between the discharge passage and the suction and discharge passage, and a discharge position that communicates the discharge passage with the suction and discharge passage and blocks communication between the suction passage and the suction and discharge passage. A switching valve equipped with a valve body that can be freely moved downward is provided so that the suction port of the suction passage opens into the molten metal of the melting furnace, and the valve body is moved to the suction position. In the operation of moving the piston to one of the pistons, the molten metal in the melting furnace is sucked into the cylinder case, and the operation of moving the piston to the other while moving the valve body to the discharge position is performed. A molten metal supply device configured to discharge the molten metal in the cylinder case to the supply passage, wherein the suction passage is opened to the valve body moving space at a position higher than the discharge passage. As described above, a fitting portion for penetrating the valve box and having the cylinder case provided therein is formed with a fitting section for internally fitting the valve box so that the valve box can be inserted / removed from above, and the supply path is provided with the fitting section. The valve box to the fitting part. In a fitted state, the supply passage is provided so as to communicate with the discharge passage, and a communication passage that is capable of communicating with the molten metal furnace at a position lower than the supply passage is formed at the bottom portion of the fitting portion, A device for supplying molten metal, wherein a closing member capable of closing the communication passage when the valve box is fitted into the fitting portion is integrally provided in the valve box. 3. The communication passage is formed so as to vertically penetrate along the insertion / extraction direction of the supply passage forming member or the valve box, and the supply passage forming member or the valve box is internally fitted to the fitting portion. The supply device for molten metal according to claim 1 or 2, wherein the closing member is provided so as to fit into the communication passage.