JP2002035995A - Isotropic pressure forming method and its forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten cycle time in an apparatus to heat, pressuring and form an article, by high temperature liquid in a pressure vessel. SOLUTION: At a carrying in and out station 10, a work composed of a plate and material piled in layers on it (an article to be pressurized) is put into a basket. The basket holding the work is transferred to a preheat station 12 and preheated there. Then it is sent to a pressure forming station to be charged into the pressure vessel. The pressure vessel, filled with high temperature water, heats, pressurizes and forms the article. After forming, the basket is returned to the carrying in and out station 10 and the work is taken out from the basket.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for forming an object to be pressed by heating and isostatic pressing by using a high-temperature liquid.

[0002]

2. Description of the Related Art There is known an apparatus in which an object to be pressurized is housed in a pressure vessel, a liquid is supplied in a state where the pressure vessel is sealed, and pressure is applied to the object to be pressurized via the liquid to form the object. I have. In this case, isostatic pressurization can be realized by pressurizing through the liquid. Further, if the temperature of the liquid is high, it is possible to perform pressure while heating. Such a device that performs isotropic pressurization while heating is used, for example, in Japanese Utility Model 4
No. 44358.

[0003] Using such an apparatus, a multilayer electronic component such as a multilayer capacitor is formed. The multilayer capacitor is manufactured by alternately laminating a conductor sheet and a ceramic green sheet having a predetermined shape, applying pressure, heating at the same time to harden the binder between the layers, and firing the ceramic. The conductor having a predetermined shape becomes an electrode, and the fired ceramic layer becomes an insulator. Actually, this is cut into a predetermined shape and used as a circuit element. When the conductor sheet and the ceramic green sheet are laminated, the green sheet is soft and the shape is not constant. Therefore, the laminate of the conductive sheet and the green sheet is placed on the plate member, and heating and pressing are performed in this state.

[0004]

As described above, a workpiece having an irregular shape before processing requires a holding means for holding the workpiece in a predetermined shape until the processing is completed. In the case of the above-mentioned laminate, a plate-like member is used as the holding means. The workpiece is housed in a pressure vessel together with the holding means, where the temperature is raised to a predetermined temperature during processing. At this time,
It is also necessary to increase the temperature of the holding means to a predetermined temperature at the time of processing, and therefore, it takes time to increase the temperature before pressing,
Prolonged use of pressure vessel. Since the tact time is determined by the time during which the pressure vessel is used, there is a problem that the tact time cannot be shortened, that is, the productivity cannot be increased.

The present invention has been made to solve the above-mentioned problems, and has as its object to provide a molding method and apparatus capable of shortening a processing time.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, an isotropic pressure molding method according to the present invention comprises a holding means for holding an object to be pressed in a predetermined shape before being housed in a pressure vessel. Is preheated. In the heating before storing the pressure vessel, the holding means can be heated while holding the object to be pressed. In this case, the object to be pressed is heated together with the holding means or indirectly heated by the heated holding means. Since the holding means is housed in the pressure vessel in a heated state, the time required for the temperature rise in the pressure vessel is reduced. Therefore, the time for using the pressure vessel can be reduced, and the tact time can be reduced. Specifically, while the pressure molding is being performed in the pressure vessel, the object to be pressed next to be molded next is preheated in a place different from the pressure vessel in parallel with this.

Further, in the isotropic pressure molding apparatus according to the present invention, at least a holding means for holding the object to be pressed in a predetermined shape is heated in advance before pressure molding. A preheating device is provided separately from the pressure vessel.
By separately providing the preheating device, the pressure molding and the preheating can be performed in parallel, and the tact time can be reduced.

[0008]

Embodiments of the present invention (hereinafter referred to as embodiments) will be described below with reference to the drawings. FIG.
It is a top view showing arrangement of a device of this embodiment. The apparatus includes a loading / unloading station 10 for placing a workpiece before molding on a basket and removing a workpiece after molding from the basket, and a preheating station 12 for preheating the workpiece placed on the basket before pressure molding. When,
It has a press forming station 14 that presses the preheated work while heating it. Guide rails 16 and 18 are provided between these stations, and the basket on which the work is placed moves along the guide rails.

FIG. 2 is a front view showing the carry-in transfer station 10 and the preheating station 12 in more detail. The pressure forming station 14 is located in the depth direction of the drawing, but is omitted in the drawing. Inside the basket 20, there are provided shelves or trays (hereinafter simply referred to as shelves) 24 on which the works 22 are placed. After the work 22 is mounted, the basket 20 moves on the guide rail 16 and is sent to the preheating station 12. Preheating station 12
, A preheating case 26 is disposed, and the conveyed basket 20 is sent into the case. Then, the opening of the preheating case is closed by the shut 28. In this state, warm air is sent from the warm air blower 32 through the duct 30 into the preheating case 26. The temperature of the hot air is determined in consideration of the heat-resistant temperature of the work and the like.

FIG. 3 shows the work 22 in detail. The laminate 34 to be subjected to pressure molding is a material for a multilayer capacitor, and is formed by alternately laminating a conductive sheet and a ceramic green sheet having a predetermined shape. Since the laminate 34 is soft, the shape of the laminate 34 alone cannot be maintained, and the laminate 34 is placed on the plate 36 in advance. The plate 36 is made of stainless steel, but any other material may be used as long as it has sufficient rigidity, good thermal conductivity, and corrosion resistance. Further, the laminate 34 and the plate 36 on which the laminate 34 is mounted are sealed by a film 38.

FIG. 4 is a side view showing the pressure forming station 14 in more detail. After preheating, basket 20
Is sent to the pressure forming station 14 by the guide rails 16 and 18. At the press forming station 14,
The basket 20 is hung on the lid 42 of the pressure vessel 40. On the other hand, the pressure vessel 40 is immersed in warm water in a thermostat 44. The hot water in the constant temperature bath 44 is sent into the pressure vessel 40 through the pipes 48 and 50 by the circulation pump 46. The hot water overflowing from the pressure vessel 40 is stored in a thermostat 44. The hot water is maintained at a temperature suitable for processing the laminate 34 by a heating means (not shown). The basket 20 suspended by the lid 42 is lowered together with the lid 42 and is charged and stored in the pressure vessel 40. Lid 42 is pressure vessel 4
When closing the opening of No. 0, the pin 52 penetrates the lid 42,
As shown in FIG. 5, the lid 42 and the pressure vessel 40 are connected.

FIG. 5 is an explanatory view of the step of pressure molding.
The work (not shown) placed on the basket 20 is housed in the pressure vessel 40. The temperature of the work 22 is raised by the preheating described above, and the pressurization can be started early after the work 22 is immersed in the hot water. Valve 54
, The pressure pump 56 is driven, and the hot water in the thermostatic bath 44 is further fed into the pressure vessel 40 through the pipes 48 and 50 to increase the pressure in the vessel. When the predetermined pressure is reached, this pressure is maintained for a predetermined time. During this time, the ceramic green sheet is pressure-formed by heating and pressing with warm water,
To cure. After a predetermined time has elapsed, the valves 54 and 58 are opened,
The pressure in the pressure vessel 40 is released.

After the pressure is released, the pin 52 is removed, the lid 42 is raised, and the basket 20 is placed on the guide rail 18. And it is sent on the guide rails 18 and 16,
Sent to the loading / unloading station where the basket 20
The work 22 after the pressure molding is taken out from the apparatus.

FIG. 6 is a diagram showing the movement of the basket 20. This apparatus has two baskets, and is denoted by reference numerals 20A and 20B in the figure. By providing two baskets, different processes can be performed in parallel, respectively, so that the tact time can be shortened as a whole. In (a), the basket 20A is in a state of being recovered from the pressure vessel 40 after the completion of the pressure molding. On the other hand, the basket 20B is in a state where the preheating is completed.
First, the basket 20A is sent to the loading / unloading station 10 as shown in (b), and then the basket 20B is sent to the pressure forming station 14 as shown in (c).

The work 22 is carried into the basket 20A sent to the carry-in / out station 10. As shown in (d), when the loading is completed, the basket 20A is sent to the preheating station 12, where the work 22 is heated. On the other hand, in parallel with this, the basket 20B is put into the pressure vessel 40, and after the work 22 is heated to a predetermined temperature, pressure molding is started. After the pressure is raised to a predetermined pressure, the pressure is maintained for a predetermined time, and then the pressure is released. When the basket 20B is recovered from the pressure vessel 40 and the heating of the work of the basket 20A is completed, the basket 20A and the basket 20B shown in FIG.

As described above, by preheating the work in the basket 20A while performing the pressure forming on the work mounted on the basket 20B, the heating performed before the pressurization in the pressure vessel is performed. Can be omitted or shortened. Therefore, the tact time can be reduced.

In the above-described embodiment, the preheating is performed by hot air. However, it is also possible to provide a tank in which a high-temperature liquid is stored, and to immerse the liquid in the basket together with the preheating. In this case, the temperature unevenness in the work can be easily reduced as compared with the preheating by the warm air. Further, as the high-temperature liquid, hot water stored in a thermostatic bath 44 of the pressure molding apparatus can be used.

Further, in the case of the present embodiment, the above-described effect can be obtained even with a preheating method in which the heat capacity of the plate 36 is large with respect to the laminated body 34 and only the plate 36 is heated. . As such a heating method, it is conceivable to arrange a heater using Joule heat, a heater using induction current, or the like in the preheating case 26 so as to face the lower surface of the plate 36, and perform heating by using the heater. Furthermore, the object to be pressed and the member holding the object are not limited to the flat plate shape, and may have any shape.

Further, more than two baskets may be provided. In this way, for example, in the above-described embodiment, three baskets can be used, and the baskets can be arranged at the transport / intake station, the preheating station, and the pressure molding station, and work can be performed in three places in parallel. In this case, it is necessary to extend the guide rail toward the opposite side of the pressure forming station to provide a retracted position of the basket.

FIG. 7 shows another example of the arrangement of each station. (A) is a plan view, and (b) is a front view. The press forming apparatus main body 100 includes a press forming station 114. Loading / unloading station 110
Is located at a position lower than the position for inputting to the pressure molding station 114 (the position indicated by reference numeral 113 in the drawing). The preheating station 112 is arranged at substantially the same height as the loading / unloading station 110.

At the loading / unloading station 110, a work is placed at a predetermined position on the basket. The basket is moved along the guide rail or the like to the preheating station 112.
Sent to In the preheating station 112, the workpiece is heated in the manner described above. When the heating is completed, the basket is lifted to a loading standby position 113 by a lift or the like, and from there, the basket 11 is pressed.
4 After the completion of the pressure molding, the basket is returned to the loading standby position 113, and is sent to the unloading standby position 111 along a guide rail or the like. The loading standby position 113 and the unloading standby position 111 are located at approximately the same height. The basket descends from the carry-out standby position 111 by a lift and is sent to the carry-in / carry-out station 110.

According to this configuration, the height of the loading / unloading station is adjusted by adjusting the height of the pressure molding apparatus main body, especially the loading standby position 113.
Can be set separately, and the workability can be improved. In addition, the basket is loaded at the loading / unloading station 11.
0, it rotates in one direction between the preheating station 112, the input standby position 113, and the unload standby position 111. Therefore, it can be seen that there is no need to provide a new configuration as compared with the above-described embodiment in which a position for evacuation had to be provided when there were three baskets.

FIG. 8 shows another example of the arrangement of each station. (A) is a plan view, and (b) is a front view. The press forming apparatus main body 200 includes a press forming station 214. Loading / unloading station 210
Is disposed at a position lower than the position for inputting the pressure into the pressure molding station 214 (the position indicated by reference numeral 213 in the figure).

At the loading / unloading station 210, a work is placed at a predetermined position on the basket. After being lifted by a lift or the like, the basket is sent to the preheating station 212 along a guide rail or the like. In the preheating station 212, the workpiece is heated by the method described above. When the heating is completed, the basket is moved along the guide rail to the loading standby position 113, where it is sent to the pressure forming station 214. After the completion of the pressure molding, the basket is returned to the loading standby position 213, from which the basket is returned along the guide rail or the like.
11 is sent. Loading standby position 213 and unloading standby position 2
11 are located at approximately the same height. The basket is lowered by the lift from the unloading standby position 211 and sent to the loading / unloading station 210.

According to this configuration, the height of the loading / unloading station is adjusted by adjusting the height of the pressure molding apparatus main body, especially the loading standby position 213.
Can be set separately, and the workability can be improved. Further, the installation area of the entire apparatus can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic arrangement of an apparatus according to an embodiment.

FIG. 2 is an explanatory view of a transfer carrying-in station and a preheating station.

FIG. 3 is a diagram showing details of a work.

FIG. 4 is an explanatory view of a pressure forming station.

FIG. 5 is an explanatory diagram of a pressure forming station and a pressure forming step.

FIG. 6 is an explanatory diagram of the operation of the device of the present embodiment.

FIG. 7 is a diagram showing another example of the arrangement of each station.

FIG. 8 is a diagram showing still another example of the arrangement of each station.

[Explanation of symbols]

10 loading / unloading station, 12 preheating station, 14 pressure molding station, 20 baskets,
22 work, 26 preheating case, 32 hot air blower,
34 laminated body (pressurized object), 36 plate (holding means), 40 pressure vessel, 42 lid, 46 circulation pump, 56 pressurizing pump.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01G 4/30 311 B28B 11/00 Z F term (Reference) 4E090 AA07 AB03 CA06 DA03 HA10 4F204 FA13 FB01 FN07 FN11 FN15 FQ01 4G054 AA05 AB01 AC04 BA03 4G055 AA07 AC09 BA22 5E082 AB03 EE03 EE11 EE23 FF05 FG06 FG26 FG54 LL02 MM22 MM24

Claims (5)

[Claims] A preheating step of preheating a holding means for holding the object to be pressed in a predetermined shape; and after the preheating step, the object to be pressed is held in the holding means. And a heating step of injecting a high-temperature liquid into the pressure vessel and heating, and performing isotropic pressurization through the liquid. And heating the object to be pressed in the preheating step. 2. The isotropic pressing method according to claim 1, wherein in the preheating step, the holding unit is heated while holding the object to be pressed. Press forming method. 3. The isotropic press forming apparatus according to claim 2, wherein the preheating step performs heating by sending a high-temperature gas. 4. The isotropic pressure molding apparatus according to claim 2, wherein the preheating step is performed in a preheating tank storing a high-temperature liquid.
An isotropic pressure molding apparatus for performing heating by immersing at least the holding means. 5. An isotropic method in which a high-temperature liquid is injected into a pressure vessel containing an object to be pressurized, heated by the liquid, and isotropically pressed through the liquid to form the object. A pressure forming apparatus, wherein the object to be pressed is charged into the pressure vessel while being held by holding means for holding the object in a predetermined shape, and before being charged into the pressure vessel. An isotropic pressure molding device, comprising: a preheating device for heating at least the holding means in advance.