JPH0522397Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention uses a heated liquid medium to encapsulate powder of metal, ceramics, etc. in a mold made of a rubber bag, etc. This invention relates to improvements in heat insulating cylinders used in pressure molding equipment.

(Prior Art) A warm isostatic pressurizing device (abbreviation: MWPS) is a device in which metal powder or ceramic powder is enclosed in a molding mold such as a rubber bag, which is then housed in a molding vessel together with a heat insulating cylinder, heated by a heating liquid medium (50-400°C) supplied into the molding vessel, and pressure molding is performed by increasing the pressure of the heating liquid medium or using a pressure piston.
As is well known, the WIP equipment is widely used along with the hot isostatic press equipment (abbreviated as HIP equipment) and the cold isostatic press equipment (abbreviated as CIP equipment). Here, an example of a piston type WIP equipment is described. That is, in FIG. 2, a high-pressure seal portion 3 is provided at the axial upper opening of the forming vessel 4.
A pressurizing piston 2 having a lower end is provided so as to be pressurized and raised and lowered by a press drive source such as a hydraulic cylinder 7, and a lower cover 5 is detachably fitted to and liquid-tightly closed at the axial lower opening. Water, castor oil,
A heating medium 22 such as silicon oil is fed to a heat medium heating unit 6 including a liquid medium tank 10, a supply pump, a supply pipe 12 equipped with a heater 8, and a recovery pipe 13.
In this piston type WIP device, the workpiece, which is a rubber bag or other mold 14 containing a desired powder 15, is placed in the molding vessel 4 through a heat insulating cylinder 11, and the heating liquid medium 22 supplied to the molding vessel 4 is heated.
When the required temperature is reached, the heat medium heating unit 6 is removed from the forming vessel 4 side, the pressurizing piston 2 is lowered to the required pressure, and the object is pressurized and molded through the compression of the heating medium 22. Of course, in a warm isostatic pressing device, it is common to use a top cover that is removably fitted and liquid-tightly closed at the axial upper opening instead of the pressurizing piston 2 described above, and to pressurize the heating medium to pressurize the object.
An example of this method is disclosed in Japanese Patent Application Laid-Open No. 61-2003.
The details of this can be found in the publication, but in this WIP device, an upper lid and a lower lid are fitted detachably and liquid-tightly to the upper and lower axial openings of a forming vessel, a forming mold filled with a powder to be formed is inserted into the forming vessel through a bucket (insulating tube), and the liquid is heated by a heating medium, and then the liquid is pressurized to perform pressure forming. In order to improve the heat exchange efficiency of the heating medium in the bucket (insulating tube), the heating medium is introduced into the inside from the lower part of the bucket (insulating tube), and is further circulated and discharged through the gap between the bucket (insulating tube) and the forming vessel. In any type of WIP device, such a cylindrical insulating tube is necessary for the insulation effect of preventing a drop in the heating medium temperature, and for preventing uneven heating caused by heat transfer due to the mold being in close contact with the forming vessel, thereby ensuring uniform pressure forming.

(Problems to be solved by the invention) The conventional heat insulating cylinder described above has the following problems. That is, the bucket (insulated cylinder) disclosed in the aforementioned Japanese Patent Application Laid-Open No. 126998/1988 is different from the conventional simple insulation cylinder in its internal and external circulation structure for the heating liquid. When a tube (tube) is used as a heat insulating tube, the insulation effect can only be expected depending on its wall thickness and material. In other words, as long as the heated liquid medium existing around the outer circumference of the bucket (insulated cylinder) is flowing, it will not have any insulation effect. However, it only has an insulating effect. Additionally, this type of heat insulating cylinder can be used only when the length inside the molded container is constant; however, in the piston type WIP device illustrated in Fig. 2, the pressurizing piston 2
The depth of entry of the piston into the molded container 4 changes depending on the size of the downward stroke of the molded container 4. Therefore, the length of the heat insulating cylinder 11 should be long enough to cover the entire length of the molded container 4 from both the upper and lower ends. It is not possible. That is, increasing the thickness of the heat insulating cylinder 11 (the same applies to the bucket) has the disadvantage of increasing the dead space of the molded container 4, and there is also a limit to the materials that can be used in the heated liquid medium. However, there are many things that lead to increased costs.
Metal-based materials are said to be optimal, but since metal-based materials generally have high thermal conductivity, a heat-insulating cylindrical structure that relies on the material and wall thickness cannot be expected to have much of a heat-insulating effect. Also, the piston type shown in Figure 2
In the WIP device, space is required for the downward movement of the piston during pressurization, and the length of the heat insulating cylinder 11 is shortened and the upper part is opened as shown in the figure at the initial stage of setting, so the heat insulating effect on the heated liquid medium 22 is We cannot expect it.

(Means for Solving the Problems) The present invention is a heat insulating cylinder used in such a warm isostatic pressurizing device, by making the heat insulating cylinder divided into upper and lower halves and having a movable structure, regardless of whether it is a piston type or an upper and lower lid type. It can be used because it has a length that can cover the entire inside length of the molded container, and by preventing convection of the heated liquid medium between the molded container and the insulating cylinder, the heated liquid medium can be heated as an insulating material. Specifically, it can be used as a molded container to which a heated liquid medium is supplied, an upper lid or pressurizing piston provided at the upper opening of the container, and a lower lid provided at the lower opening of the container. In the warm isostatic pressurizing apparatus, a mold in which the object to be processed is sealed is accommodated in the molding container via a heat insulating cylinder, and the warm isostatic pressurizing apparatus performs pressure molding via the heated liquid medium or the pressurizing piston. The insulating cylinder is divided into an upper and a lower insulating cylinder to cover the entire length of the molded container, and the upper insulating cylinder and the lower insulating cylinder are fitted to be relatively slidable, and the insulating cylinder has a pressure introduction hole that communicates the inside and outside of the insulating cylinder. is provided.

(Function) According to the present invention, a mold in which the object to be processed is sealed is housed in a molding container via a heat insulating cylinder, and the object is pressurized using a heated liquid medium or a pressure piston.

When performing pressure molding via the pressure piston, the pressure piston is inserted into the container from the upper opening of the container, pressurizes the heated liquid medium, and presses the heat insulating cylinder.

At this time, since the upper heat insulating cylinder and the lower heat insulating cylinder are fitted to be relatively slidable, the upper heat insulating cylinder slides downward relative to the lower heat insulating cylinder as the pressurizing piston approaches and descends.

At this time, the heated liquid medium inside the heat insulating cylinder and the heated liquid medium between the outer periphery of the heat insulating cylinder and the inner periphery of the container are maintained in equilibrium via the pressure introduction hole.

As described above, the present invention eliminates the need to match the length of the heat insulating cylinder and the piston stroke.

(Embodiment) A suitable embodiment of the invention will be described with reference to FIG. In the same figure, a molded container 4 in a piston-type WIP device using a pressurizing piston 2 is illustrated. In this case, the upper opening of the molded container 4 is closed with an upper lid, and the heated liquid medium is passed through the lower lid or the upper lid. A type of WIP that uses one or both to supply and discharge into the molding container 4, and that after heating the heating liquid medium, it is pressurized by a high-pressure pump and press-molded.
It goes without saying that the present invention is also applicable to the molded container 4 of the device. The insulating tube of the present invention covers the entire length of the molded container 4 with both the upper insulating tube 16 and the lower insulating tube 17, and in this case, the upper insulating tube 16 and the lower insulating tube 17 can be slid relative to each other. and is fluid-tightly fitted via a seal 18. In the embodiment, a spring 19 is elastically supported between the lower end of the upper heat insulating cylinder 16 and a flange 17a formed in a projecting shape at the lower end of the lower heat insulating cylinder 17. Corresponding to the flange 17a of the lower insulating cylinder 17, a flange 16a is also formed at the upper end of the upper insulating cylinder 16 in an overhanging manner.
By being liquid-tightly inscribed through seals 20 and 21 such as rings, the heating liquid medium 22 supplied into the upper and lower insulation cylinders 16 and 17 is heated between the upper and lower insulation cylinders 16 and 17 and the container 4. Convection is prevented. However, a pressure introduction hole 23 for balancing the pressure between the upper and lower insulating cylinders 16, 17 and the molded container 4 with the pressure inside the container is formed in a part of the circumferential side of the lower insulating cylinder 17, and 24 is for inflowing heating liquid medium. It shows. By sealing the upper and lower ends of the upper and lower heat insulating cylinders 16 and 17 as described above and preventing convection from occurring in the heating liquid medium 22, the heating liquid medium 22 itself can be used as a heat insulating material (layer). Water, castor oil, silicone oil, etc. are currently used as heating liquid media.
Silicone oil is currently the most suitable in terms of heat resistance.

In other words, the thermal conductivity of silicone oil is about 1/100 that of iron, and in detail, silicone oil has a thermal conductivity of 0.126Kcal/mh℃, while iron has a thermal conductivity of 58Kcal/mh℃, so it can be used as a sufficient heat insulating material (layer). be. Therefore, as a result of this, the wall thickness of the upper and lower insulation cylinders 16 and 17 has little effect on the insulation effect, so the thickness of the insulation cylinder can be made thinner, which reduces the weight of the insulation cylinder. , its handling and operability will also be improved.

When using the heat insulating tubes with the upper heat insulating tube 16 and the lower heat insulating tube 17 of the embodiment, as shown in the first figure, the lower lid 5 is placed concentrically in the molded container 4, and this heat insulating tube is Required mold 14 inside the cylinder
In the case of the illustrated piston-type WIP device, a known object to be processed with the required powder 15 sealed therein is charged and set concentrically, and in the case of the illustrated piston-type WIP device, it is placed in the molded container 4 using the heating medium heating unit 6 illustrated in FIG. The heating liquid medium 22 is supplied and heated to a predetermined temperature, and then the pressure piston 2 is lowered under pressure to perform pressure molding of the object to be processed in a warm region. First published in 1986
A normal type with upper and lower lids as described in Publication No. 126998.
In the case of a WIP device, a heated liquid medium is supplied into the molding container 4 through a supply/discharge passage provided in the lid, and after being heated to a predetermined temperature, the heated liquid medium is pressurized and molded.

According to the embodiment, the heat insulating cylinders 16 and 17 are disposed inside the pressure vessel 4 in a liquid-tight manner, so that no convection of the heating liquid medium 22 occurs between the molded vessel 4 and the heating liquid medium 22. The liquid medium 22 is a heat insulating material (layer)
It can be used as In addition, compared to the insulation effect caused by the material of the insulation cylinder and its wall thickness, for example, if silicone oil is used as the liquid medium, the insulation effect is much more sufficient, and there is no risk of temperature drop in the warm range, and it is possible to maintain a suitable temperature. It is possible to obtain inter-isostatic pressure treatment.

(Effect of the invention) Unlike the conventional single cylindrical structure, the heat insulating cylinders 16 and 17 of the present invention have a structure divided into upper and lower halves, and the upper insulating cylinder 16 is vertically slidable relative to the lower insulating cylinder 17. By making a movable elastic fit, not only can the entire length of the molded container 4 be easily covered as shown in FIG. Since the upper heat insulating cylinder 16 descends together with the pressurizing piston 2 without having to shorten the upper part of the cylinder to prepare for the piston entry, it is possible to eliminate the loss of insulation effect caused by shortening the heat insulating cylinder. Therefore, it can be used for both general WIP and piston type WIP.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view of an embodiment of the present invention, and FIG. 2 is a front view of an example of a piston-type WIP device. 4... Molded container, 5... Lower lid, 16... Upper heat insulating tube, 17... Lower heat insulating tube, 18, 20, 21...
... Seal, 19 ... Spring, 22 ... Heating liquid medium.

Claims (1)

[Claims for Utility Model Registration] Consisting of a molded container 4 into which a heated liquid medium 22 is supplied, an upper lid or pressurizing piston 2 provided at the upper opening of the container 4, and a lower lid 5 provided at the lower opening of the container 4. , the mold 14 in which the object to be processed 15 is enclosed is accommodated in the molding container 4 through a heat insulating tube, and the warm isostatic pressurization is carried out through pressure molding through the heated liquid medium 22 or the pressurizing piston 2. In the apparatus, the heat insulating cylinder is divided into upper and lower heat insulating cylinders 16 and 17 to cover the entire length of the molded container 4, and the upper heat insulating cylinder 16 and the lower heat insulating cylinder 17 are fitted so as to be relatively slidable, and the heat insulating cylinder A warm isostatic pressurizing device characterized in that a cylinder is provided with a pressure introduction hole 23 that communicates the inside and outside of the cylinder.