CS196982B1 - Flexible pressing mould for izostatic pressing - Google Patents

Abstract

The flexible mould is for the isostatic pressing of complicated shapes, e.g. electrical isolator guards. The mould has flat supporting webs which connect the shaped areas of the mould, the webs being positioned radially, at angles of 45 deg. A lower retaining flange (8) is located on the same height as the base seal. A thick-walled sealing flange (3) with ring extension (2) consists of the same flexible mould material, and is additionally positioned above the upper retaining flange. The sealing flange renders it unnecessary to have a 100% mechanical support of all areas of the mould.

Description

The invention relates to a flexible mold for isostatic pressing of complex shapes, such as electric shielding insulators made of powdered ceramic mass. In this case, it is desirable to obtain the above-mentioned complex shapes in a single operation without additional processing, and the molds used must at the same time exhibit sufficient shape stability and high flexibility in the removal of the articles from the mold.

In known pressing - forms of these conflicting requirements so far ^AL st es ^p lňovány completely through it tánkostánného ltáova ^ ^p ouzdra ^{(Lou T} {ka tents

1 ... 2 mm (or even less in the form of an air ball) of soft rubber, which has been given strength and shape by various measures. . A particular problem was still the desirable possibility of removing the articles from the mold.

Divisible solid hollow molds are known which perfectly or largely surround and support the flexible mold (see GDR patents 71.071 and 86.771). A disadvantage here is the high cost of manufacturing the hollow molds and the fact that there is a limitation to one shape of the workpiece which allows the article to be removed from the solid hollow mold.

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Tonuto'nedootatku - · yo prevented in a further 'flexible mold, a supporting body which consists of a body of material pěnově- ^- opojenými and other pores (vi endings * ^- Description of DDR 86772}. This has the disadvantage that the die for producing · the housing and the foam body are required, two different, but exactly matching, forms, and that in the structure of the foam there are very slight non-hogenogeneities which result in naturally inhomogeneities in the distribution of pressure and thus in the molding of the compact.

Finally, a mold is known in which a foam body is embedded in a rigid strut - which serves to remove the object from the mold - in a pressure vessel by means of - electromechanical drives for each strut (cf. GDR 120.615). This has the disadvantage of having special drives for removing the articles from the mold.

The invention aims to simplify and zhospodfrní isosteHcké Hsov ^ ^b and productions in the production facilities, for electrical shielding zejnéna isolátoxy.

The present invention is makes a ohetaou íostatioké pressed mold for molding, be inexpensively manufactured in one piece and ^- the working jetasm poctadu ,, ^which, allowing easy removal of the object - the mold while maintaining a high degree of shaping.

They report will sense the task of the invention is solved printed podpěrnými- stiffeners. Joining the creature conditional lining forming bushing arranged - and preferably radially spaced 45 °, the lower clamping ^{Getting b} ou uspoMáanou in síjná - level as ultrasound ^and bolt ^d on, and the sealing flange with an annular boss in the extension of the mold, arranged above and in addition to the known upper clamping flange, entirely in a relatively thick-walled design - of the same flexible material - providing 100% mechanical support for all parts forming sleeve - unnecessary. Due to the flexible support struts placed in the production of the thick-walled molding sleeve, a very high stability of the entire mold is achieved. Opěrné- braces are - on the mold corresponding to the desired manner uspořádány- o ^p Erny functions. Kroró ^t o ^H o umořuj ohehi ^- support ^- ^ VYZ graphite easy removal '''thick-walled articles from a molding - mold, shaped with complex geometry. The effect of spreading is already - under the action of a low vacuum.

Bez-. flexible support stiffeners are not possible to expand the mold by means of a vacuum. For výhodné- je- považováno- use thick-walled - lisovacích- forms combined alpha- flexible supporting struts that provide stability, precision molding, reproducibly and operating ^{b P} ez ecNOS ^t uj and ^{enables even} without auxiliary ^straight í.davných ^p rost ^of edků (for example - sponge rubber or backing-sheath) / removing the articles from the mold by means of a low vacuum.

To prevent penetration of the granulate of the interlocking flange and the retention of this granulate after molding in the mold (risk of cutting the mold when re-pressing with sharp edges), the lower clamping portion of the thick-walled mold is made closed. Here, it is advantageous that the forming sleeve in the lower part is made closed and, in addition to preventing the pressure build-up during isostatic compression, a clamping flange is used to be fastened in the steel support structure.

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In order to prevent the granulate from penetrating between the upper clamping flange and the formation of permanent sharp edges which lead to the cutting of the mold, the mold is extended over the upper clamping flange. closure. It is advantageous in this case that the mold is extended over the clamping flange and that the extension is in a corresponding embodiment (for example, in the form of a round). annular boss / used as seal ·

As an example embodiment, the selected shape of the mold for molding ieostatické by the high-voltage ^f iso ^la tors ·

The mold is made by casting from latex rubber · As the casting mold is used a gypsum · ^Tl ou ^MOT st ^currency thy ^of ec ^¹H o ^p OUZ ^{The hole} 6 of ^regular foam & ^d of about 10 mm · For ^p o ^d e ^p Creating shielding kontuxy ^formyl are ^p o ^l e ^N N ^{e P} forming OUZ ^d rem 6 ^l ity in point ^P with a 45 ^{h under} Ebne Perna stiffeners 7 · ^y X These braces are rigidly connected to the housing forming e. 6 · The bottom of the mold is closed on the lower clamping flange 8 to prevent the formation and dwelling of press residues between the clamping plates 2 »10. In addition, the extended mold is provided with an annular boss 2 at the end. This annular boss 2 allows sealing of the upper closure 1. This may eliminate the conventional sealing of the closure 1.

In order to prevent the pressing pressure in the longitudinal axis, the mold is built into the steel support structure * 11 by means of clamping plates -4, g, 2 »10, which is provided with openings for permitting pressurizing fluid. , which bears firmly on the mold sleeve, has no resistance due to its flexibility - the pressing process and the movement of the flexible mold material · The flexible support struts have a rather stabilizing effect on the entire mold filling and molding process ·

After ukoráení PoC ^h o ^d u Hsování it is preferable, after formation of ^DTL battery ^b taught in the recipient, or in a vacuum vessel k'tomu for forming the flexible sleeve 6 · Here, the extended flexible supporting struts χ uniform expansion of the flexible mold 6; Due to their flexibility, the support struts χ adapt ideally to the expansion process even under a slight vacuum, and the 'flexible forming sleeve' 6 on one side is prevented, making removal of the article from the mold impossible.

Claims (1)

Flexible Molds for ieostatické molded body of complex shape, such as electrical shielding ieolátory, characterized in _ that 'that is provided with a printed circuit supporting struts (7) connecting the shape of' conditional discharge forming box (6), preferably ^a UV radial US ^P ořádání in ^d s ^t u ^P u ⁴ 5 °, ^p oání from ^Ms. NaCl ^Getting ou ^{b '(8)} arranged at Ana ^d - -stejné altitude closure' and the bottom sealing flange (3) with the annular boss (2) 1 Β82 ▼ elongation of the press die through · in addition to the known upper clamping flange, all these parts being in a relatively thick-walled design with the same flexible aaterial making 10C * mechanical support of all parts of the forming sleeve (6) unnecessary.