JP4773552B2 - Vacuum exhaust head - Google Patents

Description

  The present invention relates to a vacuum exhaust head having a product exhaust port sealing mechanism.

  In the manufacturing process of a plasma display panel or the like, it is necessary to evacuate the air inside the product, seal the exhaust port of the product by sealing the gas if necessary. In order to achieve a high vacuum, it is necessary to evacuate the product while heating. As a method for sealing the exhaust port, there are a method of fusing a tip tube attached to the exhaust port and a method of bonding a lid member to the exhaust port with a hot-melt adhesive (such as molten metal).

  The vacuum exhaust heads described in Patent Documents 1 to 3 have an internal space that is sealed by being in close contact with the periphery of the exhaust port of the product, and the product is evacuated by evacuating the internal space. can do. In addition, these vacuum exhaust heads include a rod that holds the lid member in the internal space and presses the lid member against the exhaust port of the product after evacuation, but it is difficult to seal the shaft of the sliding portion of the rod. When the product is evacuated, it is necessary not to heat the shaft seal of the rod.

  For this reason, in the evacuation apparatus of Patent Documents 1 to 3, the entire evacuation head cannot be heated in the furnace, and evacuation is performed while the shaft seal portion of the rod is outside the heating furnace (chamber). . Furthermore, these vacuum exhaust devices are provided with a small heater at or near the tip of the rod to melt the adhesive and seal the exhaust port with the lid member. So that no heat is applied.

  On the other hand, in order to increase the efficiency of the evacuation process, as described in Patent Document 4, a cart that holds a large number of products and can press the evacuation head against each product is heated in a heating furnace. Thus, it is preferable to vacuum a large number of products simultaneously.

  However, as described above, if a rod that presses the lid member is provided at the exhaust port, the entire vacuum exhaust head cannot be heated in the furnace for shaft sealing of the rod, so that the production efficiency cannot be increased. It was.

JP-A-6-139935 JP 2001-195983 A JP 2004-55480 A Japanese Patent No. 3866085

  In view of the above problems, an object of the present invention is to provide a vacuum exhaust head capable of sealing an exhaust port by pressing a lid member against the exhaust port of a product in a high-temperature furnace.

  In order to solve the above problems, an evacuation head according to the present invention includes an evacuation space in which an opening is sealed by a product and can be evacuated, and is located on the opposite side of the opening and can be deformed from the evacuation space A head body defined by a partition wall and defining a differential pressure drive space that can be evacuated independently of the vacuum exhaust space; and a sealing member that is supported by the partition wall and seals the exhaust port of the product. And a holding member that is movable toward the opening of the head body by deformation of the partition wall.

  According to this structure, the vacuum exhaust space and the differential pressure drive space are simultaneously evacuated, the gas in the product is evacuated, and air is introduced into the differential pressure drive space. The holding member can be moved toward the product by being expanded, and the lid member can be pressed against the exhaust port of the product to be sealed. Further, in this configuration, since the shaft seal is not necessary for the driving mechanism of the holding member, it can be driven even when the vacuum exhaust head is heated in the furnace.

  In the vacuum exhaust head of the present invention, the holding member is supported by the partition wall and provided at a tip of a rod extending toward the opening, and the rod is axially inserted into the vacuum exhaust space. You may have a guide member hold | maintained so that sliding is possible.

  According to this configuration, since the posture and moving direction of the rod are regulated by the guide member, the movement of the holding member is stable and the exhaust port is reliably sealed.

  In the evacuation head of the present invention, the differential pressure drive space may have a smaller cross-sectional area than the evacuation space.

  According to this configuration, a step is formed at the boundary between the evacuation space and the differential pressure drive space, so that the partition wall can be fixed to the step. In addition, if the vacuum exhaust space and the differential pressure drive space are simultaneously evacuated by reducing the volume of the differential pressure drive space, the internal pressure of the differential pressure drive space is reduced first, so that the product is completely evacuated. Thus, the holding member does not protrude and block the product outlet.

  In the vacuum exhaust head of the present invention, an O-ring that is in close contact with the product may be provided around the opening.

  According to this configuration, airtightness between the vacuum exhaust head and the product can be ensured.

  According to the present invention, the holding member is driven by the deformation of the partition inside the vacuum exhaust head, and the lid member that seals the exhaust port of the product is pressed against the product, so that the holding member and the drive mechanism of the holding member are completely evacuated. It is housed inside the exhaust head. For this reason, the shaft seal of the drive mechanism is unnecessary, and there is no heat-sensitive portion, so that the entire vacuum exhaust head can be exposed to a high temperature in the heating furnace. This makes it possible to simplify the evacuation process and increase the processing capacity.

It is sectional drawing of the vacuum exhaust head of 1st Embodiment of this invention. It is sectional drawing at the time of the exhaust port sealing of the vacuum exhaust head of FIG. It is a processing cart provided with many vacuum exhaust heads of FIG. It is sectional drawing of the vacuum exhaust head of 2nd Embodiment of this invention.

  Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 shows an evacuation head 1 according to a first embodiment of the present invention. The evacuation head 1 is for connecting a hollow product 2 such as a plasma display panel and a vacuum source 3 and evacuating and sealing the gas inside the product 2.

  The evacuation head 1 has a substantially bottomed cylindrical head body 4 with an open top. The internal space of the head body 4 is divided into a vacuum exhaust space 5 having a large upper sectional area and a differential pressure driving space 6 having a smaller sectional area on the lower side (opposite the opening) by a rubber partition 7. It is divided. The diaphragm 7 is bonded and fixed to a step portion between the vacuum exhaust space 5 and the differential pressure drive space 6.

  A rod 8 extending vertically toward the opening of the head body 4 is fixed at the center of the diaphragm 7. The rod 8 has a table-like holding member 11 that holds a lid member 10 for sealing the exhaust port 9 of the product 2 at the upper end. The rod 8 is slidably held by a plate-shaped guide member 12 disposed in the evacuation space 5. The guide member 12 has a hole 12a that allows air to pass therethrough.

  The head body 4 has exhaust passages 13 and 14 that open to the vacuum exhaust space 5 and the differential pressure drive space 6, respectively. The evacuation space 5 and the differential pressure drive space 6 are connected to a vacuum circuit 17 for supplying a vacuum pressure (evacuation) from the vacuum source 3 via pressure-resistant hoses 15 and 16, respectively.

  Further, an O-ring 18 is provided at the upper end so as to surround the opening, and the product 2 is hermetically adhered. Further, the head body 4 has a cooling flow path 20 for circulating the cooling water supplied from the cold water source 19.

  The vacuum circuit 17 connects the vacuum exhaust space 5 to the vacuum source 3 via the vacuum shut-off valve 21 and the flow rate control valve 22, and includes a pipe line including a pressure switch 23 for detecting the internal pressure of the vacuum exhaust space 5, and a vacuum A pipe branched from the pipe connected to the exhaust space 5 and connected to the differential pressure drive space 6 via the communication valve 24 and provided with a pressure switch 25 for detecting the internal pressure of the differential pressure drive space 6; Have.

  The pipe connected to the vacuum exhaust space 5 is provided with a vacuum exhaust space release valve 26 for opening the vacuum exhaust space 5 to the atmosphere, and the pipe connected to the differential pressure drive space 6 has a differential pressure drive. A differential pressure drive space release valve 28 that opens the space 6 to the atmosphere via a flow rate adjustment valve 27 is provided.

  The vacuum circuit 17 also includes pressure gauges 29 and 30 so that an operator can visually check the internal pressures of the vacuum exhaust space 5 and the differential pressure drive space 6.

  When the product 2 is evacuated by the vacuum exhaust head 1, the lid member 10 coated with the adhesive 31 is placed on the holding member 11 of the rod 8. The rod 8 evacuates the product 2 in which the holding member 11 is held in the evacuating space 5 and the lid member 10 is disposed on the evacuating head 1 in a state where the evacuating space 5 and the differential pressure driving space 6 are opened to the atmosphere. Separate sufficiently from the mouth 9. At this time, the diaphragm 7 is slightly bent toward the differential pressure drive space 6 due to the weight of the rod 8 and the holding member 11.

  While the vacuum exhaust head 1 and the product 2 are placed in a heating furnace and heated, the communication valve 24 of the vacuum circuit 17 is opened, and then the vacuum shut-off valve 21 is opened, so that the vacuum exhaust space 5 and the differential pressure are opened. The drive space 6 is evacuated simultaneously. The vacuum exhaust head 1 is in close contact with the product 2 by an O-ring 18, and the gas in the product 2 passes through the exhaust port 9 of the product 2, the hole 12 a of the guide member 12 disposed in the vacuum exhaust space 5, and the exhaust path 13. Is exhausted to the vacuum circuit 17.

  At this time, since the vacuum exhaust space 5 communicates with the internal space of the product 2, the volume is large, and the differential pressure drive space 6 having a small volume is first evacuated. For this reason, the rubber partition 7 is elastically deformed so as to protrude toward the differential pressure drive space 6 and lowers the rod 8. Thereby, before the evacuation of the product 2 is completed, the rod 8 is not raised and the adhesive 31 is not brought into contact with the product 2.

  When the evacuation of the product 2 is completed, the pressure difference between the evacuation space 5 and the differential pressure drive space 6 disappears, so that the partition wall 7 is located at substantially the same position as when the evacuation space 5 and the differential pressure drive space 6 are opened to the atmosphere. The rod 8 is supported.

  The vacuum circuit 17 has a gas supply path so that after the product 2 is evacuated, a small amount of gas such as a luminescent gas for a plasma display panel can be introduced into the product 2 through the vacuum exhaust space 5. May be.

  When the evacuation of the product 2 is completed (the pressure switch 23 detects a predetermined vacuum pressure) and the gas is supplied to the product 2 as necessary, the communication valve 24 of the vacuum circuit 17 is closed and then the differential pressure is driven. The space release valve 28 is opened to open only the differential pressure drive space 6 to the atmosphere. Then, since the internal pressure of the differential pressure drive space 6 becomes higher than the internal pressure of the vacuum exhaust space 5, the partition wall 7 protrudes toward the vacuum exhaust space 5 and pushes up the rod 8 as shown in FIG. As a result, the holding member 11 moves toward the opening of the head body 4, presses the lid member 10 against the product 2, and covers the exhaust port 9 with the lid member 10.

  The head body 4 is cooled by cooling water circulating in the cooling flow path 19 to maintain the rubber partition wall 7 and the O-ring 18 at a heat resistant temperature or lower. Since the temperature around the exhaust port 9 of the product 2 that is not directly cooled by the cooling water increases as the furnace temperature rises, the adhesive 31 applied to the pressed lid member 10 is melted.

  Thereafter, the internal pressure of the differential pressure driving space 6 is maintained higher than that of the vacuum exhaust space 5 and the lid member 10 is pressed and the temperature inside the furnace is lowered to solidify the adhesive 31, thereby closing the lid member 10 of the exhaust port 9. Ensuring sealing with.

  Subsequently, after the vacuum exhaust head 1 is taken out together with the product 2 from the furnace, the vacuum shut-off valve 21 is closed, and then the vacuum exhaust space release valve 26 is opened to open the vacuum exhaust space 5 to the atmosphere. Then, the pressure difference between the evacuation space 5 and the differential pressure drive space 6 disappears again, so that the partition wall 7 is lowered and the rod 8 is retracted. At this time, since the evacuation space 5 is at atmospheric pressure, the adhesion of the O-ring 18 is lost, and the evacuation head 1 and the product 2 can be separated and the product 2 can be sent to the next process. .

  In the vacuum exhaust head 1, the partition wall 7 is accommodated in the head main body 4 cooled by the cooling water, and is not directly exposed to the heat of the heating furnace. For this reason, even if the partition wall 7 is inferior in heat resistance, the partition wall 7 can expand and contract without breaking in a state where the vacuum exhaust head 1 is disposed in the heating furnace. Note that other types of cooling fluid may be used instead of the cooling water.

  Further, in the vacuum exhaust head 1, if the air release speed of the differential pressure drive space 6, that is, the air supply speed to the differential pressure drive space 6 is adjusted by the opening degree of the flow rate control valve 27, the rising speed of the rod 8. And the scattering of the adhesive 31 can be prevented.

  Since the vacuum exhaust head 1 of the present invention is small and can be heated together with the product 2 in a furnace, it is attached in parallel to a cart 32 holding a large number of products 2 as shown in FIG. 2 can be evacuated and sealed simultaneously.

  FIG. 4 shows an evacuation head 1a according to a second embodiment of the present invention. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  In the vacuum exhaust head 1a, a disc 33 is provided at the lower end of the rod 8, and a differential pressure driving space 6 is defined by a metal bellows 34 sealed at both ends by the bottom wall of the head body 4 and the disc 33. Has been. That is, in the present embodiment, the bellows 34 is a partition wall that divides the vacuum exhaust space 5 and the differential pressure drive space 6.

  Also in this evacuation head 1a, the bellows 34 can be expanded and contracted and the rod 8 can be moved up and down by the pressure difference between the evacuation space 5 and the differential pressure drive space 6.

  In the above embodiment, the guide member 12 regulates the posture and moving direction of the rod 8, but the guide member 12 may be omitted as long as the expansion and contraction of the partition wall is stable, and accordingly the head You may make the height of the main body 4 low.

  Further, in the pipe line connected to the differential pressure driving space 6 of the vacuum circuit 17 of the present embodiment, compressed air adjusted in pressure by a regulator 36 is supplied from a compressed air source 35 such as an air compressor through a compressed air supply valve 37. Can be supplied.

  By supplying the compressed air to the differential pressure drive space 6 after the differential pressure drive space 6 is opened to the atmosphere or with the communication valve 24 and the differential pressure drive space release valve 28 closed with the release of the atmosphere omitted. The lid member 10 can be pressed by the product 2 with a stronger force. Thereby, even when the cross-sectional area of the differential pressure drive space 6 is small, it is possible to ensure the close contact of the lid member 10 with the product 2.

  Further, when the vacuum exhaust head 1a and the product 2 are separated, the vacuum exhaust space 5 can be supplied by opening the communication valve 24 and supplying the compressed air to the vacuum exhaust space 5 without opening the vacuum exhaust space release valve 26. The air can be quickly supplied to the vacuum exhaust head 1a from the product 2 quickly. This is particularly effective when the diameter of the conduit of the vacuum circuit 17 and the pressure-resistant hoses 15 and 16 are small and the path length is long.

DESCRIPTION OF SYMBOLS 1 ... Vacuum exhaust head 2 ... Product 3 ... Vacuum source 4 ... Head main body 5 ... Vacuum exhaust space 6 ... Differential pressure drive space 7 ... Bulkhead 8 ... Rod 9 ... Exhaust port 10 ... Lid member 11 ... Holding member 12 ... Guide member 13 , 14 ... Exhaust passage 17 ... Vacuum circuit 18 ... O-ring 19 ... Cold water source 20 ... Cooling passage 31 ... Adhesive 32 ... Cart 33 ... Disc 34 ... Bellows (partition wall)

Claims (4)

The opening is sealed by a product and can be evacuated, and is located on the opposite side of the opening and is divided by the evacuated space and a deformable partition, and is evacuated independently of the evacuated space. A head body defining a possible differential pressure drive space;
And a holding member that is supported by the partition wall and holds a sealing member that seals an exhaust port of the product, and is movable toward the opening of the head body by deformation of the partition wall. head. The holding member is supported by the partition wall and is provided at a tip of a rod extending toward the opening,
The vacuum exhaust head according to claim 1, further comprising a guide member that holds the rod slidably in the axial direction in the vacuum exhaust space.   The vacuum exhaust head according to claim 1, wherein the differential pressure driving space has a smaller cross-sectional area than the vacuum exhaust space.   The vacuum exhaust head according to claim 1, further comprising an O-ring that is in close contact with the product around the opening.

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