ES2421457B1 - Isostatic punch holder for molds for the manufacture of ceramic pieces - Google Patents

Abstract

Isostatic punch-holder device for molds for the manufacture of ceramic pieces comprising a base plate (1) with a first face (1a) provided with a plurality of recesses (8, 8 ’) with base paths (8a, 8a’) and internal perimeter walls (8b, 8b ’), two punch-holder blocks (2, 2’) each partially housed in one of the recesses (8, 8 ’), presenting each punch-holder block (2, 2’) a widened base (2a, 2a ’) guided in the first part of the inner perimeter wall (8b, 8c) and a horizontal outer step (2b) on which an elastic joint (5, 5’) sits hugging the carrier block punches (2, 2 ’), an isostatic chamber (10, 10’) defined between the inside face of the punch holder block (2, 2 ’) and the base (8th, 8th’) of the recess (8, 8 ’) filled with an incompressible liquid, the isostatic chambers (10, 10 ’) interconnected with each other to allow the passage of the liquid, and elastic retraction means to retract each punch holder block (2, 2 ’) towards the base (8a, 8a’) of the recess (8, 8 ’) in which it is housed, in which each internal perimeter wall (8b, 8b’) of the recess ( 8, 8 ’) has a horizontal internal step (8c) so that the recess (8, 8’) has a first part close to its base (8a, 8a ’) and a widened second part, in which a clamping flange (6, 6 ’) seated in said internal step (8c) and enclosing said elastic joint (5, 5’).

Description

ISOSTATIC PUNCH HOLDER DEVICE FOR MOLDS FOR THE

MANUFACTURE OF CERAMIC PARTS

TECHNICAL FIELD OF THE INVENTION

The present invention falls within the technical field of the devices of

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molding and, particularly of isostatic molds, for the manufacture of articles

Ceramics, such as tiles.

BACKGROUND OF THE INVENTION

In the manufacture of flat ceramic articles, such as tiles, slabs and

tiles, it is usual to use penetrating molds composed of two semi-molds, one

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male provided with a plurality of upper punches, and another female with a die

of housings or alveoli, in which a ceramic material, for example earth or

clay that may be present in powder form, from which they are formed,

by the press action of the upper punches, compacted pieces that

subsequently undergo further treatments, such as enamelling,

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decoration and cooking to obtain the corresponding flat ceramic articles.

For the realization of the compacted parts in such penetrating molds,

requires a homogeneous load of the ceramic material in the cavities of the matrix to

obtain a pressed body as homogeneous as possible, for which there are several

systems. However, in industrial practice it is very difficult to get a load

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totally homogeneous ceramic material in all the alveoli of the mold matrix

female. That lack of homogeneity in the loading of the ceramic material in the alveoli

It implies the problem that, when the ceramic material present in the alveoli is submitted

when pressing with the same pressure, different bulk densities occur than

they can cause and, in fact cause, after cooking the pressed pieces,

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these present defects such as, for example, variations in their size and appearance.

To avoid the generation of different densities in the pressed parts, they have been

Designed isostatic punch systems to try to regulate material pressing

ceramic loaded in the alveoli equalizing the pressures, such as those described,

for example, in European Patent Application EP1403017 A2 and comprising

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a motherboard with a first face provided with a plurality of recesses with

paths bases and internal perimeter walls, two separate punch-holder blocks

each partially in one of the recesses, presenting each carrier block

punches an outer face with coupling means for at least one punch, and a

inner face facing the base of the recess in which it is housed, the block being

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  orthogonally movable punch holder relative to the base of the recess, a

isostatic chamber defined between the inside face of the punch holder block and the base of the

filled with an incompressible liquid, the isostatic chambers being

intercommunicated with each other to allow the passage of liquid, as well as retraction means

elastic to retract each punch holder block towards the base of the recess in which

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It is hosted.

However, these types of punch systems always suffer from one part.

of the isostatic punch which is rigid namely its outer edge whose stiffness limits the

isostatic compensation capability of the punch system and therefore fails

completely solve the problem of variant densities in

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compressed parts from loads of non-homogeneous materials in the alveoli of

the matrix of the female half-mold.

DESCRIPTION OF THE INVENTION

The present invention aims to overcome the drawbacks of the state of the

technique detailed above, by means of an isostatic punch device for

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molds for the manufacture of flat ceramic pieces comprising

a motherboard with a first face provided with a plurality of recesses

with paths and inner perimeter walls;

two punch-holder blocks each partially housed in one of the

recessed, each punching block presenting an outer face with means of

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coupling for at least one punch, and an inner face facing the base of the

recessed in which it is housed, being the punch block orthogonally

movable with respect to the base of the recess;

a defined isostatic chamber between the inside face of the punch holder block and

the base of the re-sunk filled with an incompressible liquid, the chambers being

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isostatic intercommunicated with each other to allow the passage of liquid;

elastic retraction means to retract each punch block towards the

base of the recess where it is housed;

characterized because

each punch holder block comprises a widened base guided in the

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first part of the inner perimeter wall and a horizontal outer step in which

seat an elastic joint hugging the punch holder block;

each internal perimeter wall has a horizontal internal step so

that the recess has a first part near the base of the recess and a

second part widened;

a flange is immobilized on the widened part of the inner perimeter wall

clamping seated in said internal step that hugs the punch holder and encloses

said elastic seal.

The clamping flange supports the strength of the elastic seal inside

that by the action of the flange and the elastic joint, the punch holder block is

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subjected to a pushing force directed towards the base of the recess. This flange can

have a cross section in L between whose branches the elastic seal is arranged.

Isostatic cameras can be intercommunicated through a camera

distribution located on the motherboard above the bases of the recesses and communicated

with isostatic chambers through through holes. The motherboard can also be

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equipped with heating means and an inlet / outlet for the incompressible liquid and a

safety valve to avoid overpressures in isostatic chambers.

To guide the movement of the punch-holder blocks and avoid their

offset in the recesses, the punch holder device may be provided with

two guide bands, immobilized respectively between the widened base of each

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punch holder block and the respective first part of the inner perimeter wall of the

sunk The guide bands also facilitate the sliding of the carrier blocks.

punches The guide band can be mounted on a peripheral throat in the part

widening of the punch holder block.

To prevent the release of incompressible fluid from isostatic chambers, they can

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be provided with internal sealing gaskets, such as o-rings

arranged perimetrically respectively between the base of the recess and the inner face

of the punch holder block. The internal joints can be arranged in respective

starters provided at the base of the recesses and jo on the internal faces of the blocks

punch holder

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Preferably, the punch holder device according to the invention

it also includes a bellows with a horizontal section fixed on the first

face of the base plate and a vertical section fixed peripherally to the punch holder block.

The horizontal section of the bellows is attached to the clamping flange. This

shape, the system is protected against the entry of dust and other foreign bodies

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position between the punch holder block and the corresponding recess wall.

In accordance with the foregoing, the present invention exceeds

the drawbacks of the state of the art by a robust, reliable and reliable device

simple to manufacture

BRIEF DESCRIPTION OF THE FIGURES

Aspects and embodiments of the invention are described below on the basis

of schematic drawings, in which Figure 1 is a bottom perspective view of a punch holder device

according to an embodiment of the invention; Figure 2 is a bottom plan view of the device shown in Figure 1; Figure 3 is an exploded view of the device shown in Figure 1; Figure 4 is a sectional view along the line A-A marked in Figure 2 and of a

enlarged detail view. In these figures numerical references appear that identify the following

elements:

one

motherboard

the

first face

2, 2 '

punch holder block

2nd, 2nd '

widened base

2b

outer step

3.3 '

internal seal

4, 4 '

guide band

H.H'

elastic joint

6, 6 '

clamping flange

7, 7 '

dust boot

7a

horizontal section

7b

vertical section

8.8 '

sunk

8th, 8th '

base

8b, 8b '

internal perimeter wall

Be

internal step

9

distribution chamber

9a

passage hole

10, 10 '

isostatic chamber

11.11 '

electromagnetic coil

MODES OF CARRYING OUT THE INVENTION

The isostatic punch-holder device for molds for the manufacture of ceramic pieces whose embodiment is shown in the figures, comprises a base plate -1-with a first face -the-provided with a plurality of recesses -8, 8'-with paths bases -8a, 8a'-and internal perimeter walls -8b, 8b'-, as well as two punch-holder blocks -2, 2'-each partially housed in one of the recesses -8, 8'-.

Each punch holder block -2, 2'-has an outer face with means of

U-shaped coupling of electromagnetic coils for at least one punch -no

shown in the figures-, and an inner face facing the base -Ba, Ba'-del rehundido -B,

B'-in which it is hosted. Each punch holder block -2, 2'-is orthogonally

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movable with respect to the base -Ba, Ba'-del rehundido -B, B'-corresponding.

Each punch holder block -2, 2'-is retained in the recess -B, B'-in which

it is housed by elastic retraction means that retract the block

punch holder -2, 2'-towards the base -Ba, Ba'-. This is achieved thanks to one part.

widened -2, 2a-of the punch holder block -2, 2'-guided in the first part of the

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internal perimeter wall -Bb, Be-y an outer step -2b-horizontal block

punch holder -2-on which an elastic joint sits -5, 5'-hugging the block

punch holder -2, 2'-, and an internal step -Be-horizontal on the perimeter wall-Bb, Bb'-

of the recess -B, B'-which in this way presents a first part close to the base -Ba,

Ba'-del rehundido -B, B'-and a second widened part, and a clamping flange -6, 6-of

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L-cross section immobilized on the widened part of the perimeter wall

internal -Bb, Bb'-, seated on said internal step -Be-and that hugs the punch holder-

2-and encloses said elastic seal -5, 5'-. The clamping flange -6, 6'-supports inside the

force of the elastic joint -5, 5'-so that by the action of the flange -6, 6'-and the joint

elastic -5, 5'-, the punch holder block -2, 2a-is subjected to a pushing force

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directed towards the base -Ba, Ba'-del rehundido -B, B-.

The punch holder device further comprises a dust boot -7, 7'-

with a horizontal section-7a-fixed on the first face -the-of the motherboard -1- and a section

vertical -7b-fixed peripherally to the punch holder block -2, 2'-, and because the section

horizontal-7a-of the bellows -7-bellows is attached to the clamping flange.

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Between the base -Ba, Ba'-del rehundido -B, B'-and the inside face of the block

punch holder -2, 2'-an internal sealing gasket -3, 3'- is arranged perimetrically,

specifically an O-ring, while between the widened base -2a, 2a'-del

punch holder block -2, 2'-and the first part of the inner perimeter wall -Bb, Bb'-

of the recess -B, B'-a guide band immobilized in a throat is arranged

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peripheral in the widened base -2a, 2a'-of the punch holder block -2, 2'-.

As you can see, between the inside face of the punch holder block -2, 2'-y

the base -Ba, Ba'-del rehundido -B, B'-an isostatic chamber -10, 10'-fillable is defined

of an incompressible liquid, the isostatic chambers being -10, 10'-intercommunicated

each other to allow the liquid to pass through a distribution chamber -9-

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  located on the base plate -1-above the bases -Ba, Ba'-de los rehundidos -B, B'-y

communicated with isostatic chambers -10, 10'-through through holes -11-. This allows the punch holder device according to the present invention to function as follows:

In an initial phase or resting phase, the inner faces of the punch-holder blocks -2, 2'-are, separated by the incompressible liquid present in the isostatic chambers -10, 10'-, at equal distances from the bases - 8a, 8a'-of the recesses -8, 8'-corresponding. When the punch-holder device is lowered towards the socket array -not shown in the figures- in which the powder of ceramic material to be pressed is found. When one of the punches connected to their respective punch-holder block -2'-contacts the ceramic material, it exerts a pressure on the incompressible fluid contained in the isostatic chamber -lO-corresponding, so that a part of the incompressible liquid contained in that isostatic chamber -10, -is displaced, through the distribution chamber -9-, towards the other isostatic chamber -10'-whose punch is not yet in contact with the ceramic material present in the other socket of the matrix. When the other punch comes into contact and presses the ceramic material present in another socket of the die, it exerts pressure on the other punch holder blocks -2'-so that a part of the incompressible liquid present in the corresponding isostatic chamber - 10'-is moved to the other isostatic chamber -10-, achieving, in accordance with Pascal's Law, that the pressures in the chambers -10, 10'-are equalized, thus achieving a compensation of the pressures exerted by the punches on the respective ceramic materials and, thus, that the pressed ceramic pieces all have basically the same apparent density and the consequent advantages in the quality of the cooked ceramic pieces.

Claims (1)

a motherboard a motherboard 1. Isostatic punch holder for molds for manufacturing parts ceramics that comprises base (Ba,