EP0620057B1 - Die out of two pieces for swaging and/or crimping press. - Google Patents

Description

The invention relates to a set of two matrices intended for equip a press to shrink and / or crimp a tubular part according to the preamble of claim 1 (see for example GB-A-987 726).

It is known to crimp a tip, or fitting, arranged in a pipe by means of an outer metal ring which is generally cold shrunk.

The nozzle is generally provided with peripheral bosses, which are thus anchored in the material of the pipe by tightening said outer ring.

To shrink the ring, tools can be used with jaws which tighten radially on the ring.

However, this type of tool is generally quite bulky and expensive. In addition, the ring is not shrunk over its entire circumference, it is driven in by each bit.

To crimp, you can also use a hydraulic press manual or not, which has a head in which there are two facing dies, having a hollow imprint, one being immobilized while the other, movably mounted, is biased by the jack hydraulic press.

We understand that it suffices to have the parts to be crimped between the two dies and operate the press until a tightening is obtained sufficient.

In this way, the aforementioned ends can be crimped in the pipes, but also sockets on cables, etc.

For that, it is enough to use matrices of suitable forms, the two matrices of course not necessarily having the same shape.

However, to crimp by means of a ring as mentioned above, the known matrices can be of the type circular or polygonal (e.g. hexagonal), i.e. the two matrices closed one on the other form a surface cylindrical or polygonal tubular tightened in relation to the shape initial cylindrical of the ring.

We understand, however, that the two matrices are tightening towards each other and that inevitably, in the place that should constitute a junction surface for the matrices, part of the ring material is pinched.

If the hexagonal dies give fairly good results, it is clear that the ring is marked and is not further restricted uniformly.

With dies whose impressions are circular cylindrical (with a diameter of course less than the diameter of the ring), pinching can be very important.

Document DE-B-1096442 describes a set of two matrices intended to equip a press to clamp a part, the dies having each a hollow imprint which extends laterally on each edge by a junction surface of the crenellated matrices forming teeth and gaps transverse to the axis of the impression so that said teeth are provided for overlap each other during translational reconciliation mutual matrices carried out by the press until said dies constitute the closed interior surface desired for the shaped product. This device is intended to tighten a sleeve around of two cables and the footprint of each matrix is a part of polyhedron. The set of two matrices according to the invention is defined in the claim 1. claim 6 relates to a press hydraulic comprising a set of two dies according to the invention and claim 7 the use of such a game to perform a crimping of a cylindrical ring on a pipe.

Such a set of two matrices makes it possible to minimize the pinching phenomenon, which is not besides not the problem to be solved in the aforementioned German document in which, moreover, the teeth of a matrix do not overlap to the bottom of the interstices of the other.

Advantageously, the dimensions of the teeth of each matrix are identical while the central axis of the cylinder part or footprint of each matrix is determined by the intersection of the plane longitudinal of the matrix with the mid-tooth division plane of said dies so that the substantially cylindrical circular surface formed by matrices is obtained when the teeth of a matrix are nested to the bottom of the interstices of the other matrix. This ensures perfect calibration of the diameters to be restricted or crimp, while limiting the crushing of the parts.

Preferably, the two matrices are identical to each other and are intended to be presented from the front, but returned one by relation to the other, so that the teeth of one fit in the interstices of the other.

Advantageously, the teeth are slightly chamfered or rounded as well as the bottom of each gap on its inner edge.

The matrices according to the invention are quite well suited, but not exclusively, to equip a hydraulic press of the type mentioned above and apply in particular to cold crimping a ring as mentioned above, for fixing a nozzle or fitting in a pipe.

• la figure 1 montre une presse hydraulique manuelle pourvue de deux matrices selon l'invention prêtes au serrage,
• la figure 2 montre la tête de la presse de la figure 1 après rapprochement des matrices par l'action du vérin hydraulique,
• la figure 3 montre les pièces avant assemblage prévues pour le sertissage d'un raccord dans un tuyau,
• la figure 4 montre les pièces de la figure 3 assemblées,
• les figures 5, 6 et 7 montrent une matrice selon l'invention respectivement en élévation vue dans la direction de l'axe longitudinal de l'empreinte, en vue de dessus et en élévation transversale.

The invention will be clearly understood on reading the description which follows and which refers to the appended drawings in which:

• FIG. 1 shows a manual hydraulic press provided with two dies according to the invention ready for tightening,
• FIG. 2 shows the head of the press of FIG. 1 after the dies have been brought together by the action of the hydraulic cylinder,
• FIG. 3 shows the parts before assembly provided for crimping a fitting in a pipe,
• FIG. 4 shows the parts of FIG. 3 assembled,
• Figures 5, 6 and 7 show a matrix according to the invention respectively in elevation seen in the direction of the longitudinal axis of the imprint, in top view and in transverse elevation.

In Figure 1, we can see a tool constituting a press hydraulic manual and which is provided with a head 1 in which are mounted two dies 2 and 2 '.

It is understood that the head 1 can open for the establishment matrices, the matrix 2 'being fixed here while the matrix 2 is mobile and can be requested by the piston 3 (figure 2) of a jack hydraulics fitted to the tool.

The two matrices 2 and 2 'are identical and are represented in more detail under reference 2 in Figures 5 to 7.

The matrix thus represented in FIGS. 5 to 7 comprises a tail 4 for mounting in the head 1 and ribs 5a, 5b of guidance.

The matrix 2 has a hollow imprint 6 of cylindrical shape circular which extends on the edges of its opening by a crenellated surface 7a, 7b forming teeth as shown, directed transversely to the axis of the imprint 6. As shown more particularly in FIG. 7, the surfaces crenellated 7a, 7b are therefore constituted by a succession of teeth and interstices. Advantageously, the teeth and the interstices have the same dimensions while each surface is delimited by side by a tooth, for example 8a, 8b (Figures 6 and 7) and on the other side by a recess 8'a, 8'b corresponding to the size of a gap (Figures 5 to 7).

As shown in Figure 5, the surfaces 7a, 7b extend footprint 6 substantially tangentially and we can see also that the teeth have a slight chamfer.

We can also see, still in Figure 5, that the interstices are slightly rounded, as indicated by references R, on the inner side, i.e. on the junction side with the surface of the imprint.

Furthermore, if the plane 9 of FIGS. 5 and 7 represents the plane sharing half-teeth of surfaces 7a, 7b, the intersection of this plane with the longitudinal plane 10 determines the axis 11 (Figure 5) of the cylindrical part or impression 6.

In Figure 1, we can see the axes 11, 11 'respectively cylindrical impressions 6, 6 'of the dies 2 and 2'.

Again in FIG. 1, it is understood that the matrices 2 and 2 ′ are returned relative to each other so that the teeth of one nest in the interstices of the other when the tool is activated and the dies approach one towards the other by a translative movement.

We can thus obtain the clamping position shown on Figure 2, position in which the axes 11 and 11 'coincide.

As this figure 2 clearly shows, the imprints 6 and 6 ' thus connected after joining the crenellated surfaces of each matrix, constitute a surface of generally circular cylindrical shape, the teeth of one of the matrices coming into abutment at the end of race to the bottom of the interstices of the other matrix. However, because from the substantially tangential departure of the crenellated surfaces of the matrices and the fact that the axis 11 of the cylindrical part is in the plane 9 (figure 5) for each matrix, the planes containing the interior faces teeth of a matrix intersect with the corresponding planes of the other matrix at the junction generators by forming very open dihedral angles.

The rounded parts, noted R, of the interstices favor as for them shrinking without tearing material from the part to shape, without causing any rupture or corrosion, and further facilitate dislocation during separation of the dies.

Figures 3 and 4 show a pipe 12 in which we want crimp a ferrule or fitting 13 provided with a loose nut 14.

Conventionally, the connector 13 has bosses for slightly enter the pipe 12.

To perform this crimping, there is a ring 15, a diameter slightly greater than the pipe 12, around the latter, after fitting the end piece 13 and its nut 14 (Figure 4).

It is then enough to use a tool of the type of that of the figure 1 with dies slightly smaller in diameter than of the ring 15 to restrict it.

It is clear that the crenellated surfaces of the matrices which thus overlap promote a substantially uniform shrinkage of the ring 15, the bosses of the connector 13 coming to anchor in the pipe 12.

However, this application is obviously given as example. We can indeed shrink any ring on any other element, or even directly shrink a tubular element.

In addition, if the invention is more particularly intended for to shrink a circular part, this one can present another form.

Claims (7)

1. Set of two dies designed to be fitted to a press for swaging and/or crimping a tubular metal part, the dies (2, 2') each exhibiting a hollow imprint (6, 6') forming a circular cylinder portion which is extended laterally on each edge by a toothed die junction surface (7a, 7b) such that said surfaces are designed to be imbricated in one another at the time of the mutual translatory movement of the dies (2, 2') towards one another produced by the press, while the dimensions of the imprints and the toothed surfaces (7a, 7b) are such that the two completely imbricated dies form an internal surface of substantially circular cylindrical general shape, characterised in that the toothed surfaces (7a, 7b) of each die each form a plurality of teeth and gaps, and extend the hollow imprint (6) substantially tangential to the latter, the planes containing the internal faces of said teeth of one die intersecting with the corresponding planes of the other die forming dihedral angles.
2. Set of two dies according to claim 1, characterised in that the dimensions of the teeth of each die are identical while the central axis (11, 11') of the cylinder portion or imprint (6, 6') of each die is determined by the intersection of the longitudinal plane (10) of the die with the half-tooth dividing plane (9) of said dies such that the substantially circular cylindrical surface formed by the dies is obtained when the teeth of one die are imbricated to the bottom of the gaps of the other die.
3. Set of two dies according to one of claims 1 and 2, characterised in that the two dies (2, 2') are identical and in that their toothed surfaces (7a, 7b) are constituted by a succession of teeth and gaps with the same dimensions and delimited on one side by a tooth (8a, 8b) and on the other by a recess (8'a, 8'b) such that the two dies (2, 2') are designed to face one another, but to be turned one in relation to the other such that the teeth of one fit in the gaps of the other.
4. Set of two dies according to one of claims 1 to 3, characterised in that the teeth are slightly chamfered or rounded.
5. Set of two dies according to one of claims 1 to 4, characterised in that the bottom of each gap is slightly chamfered or rounded (R) on its inner edge.
6. Manual hydraulic press comprising a set of two dies (2, 2') according to one of claims 1 to 5, fitted in a head (1), one (2') of the dies being immobilised while the other die (2), fitted so as to be mobile, is moved by the hydraulic jack of said press.
7. Use of a set of two dies according to one of claims 1 to 6, for effecting crimping by cold swaging of a cylindrical ring (15) on a pipe (12) in which a connector or end piece (13) provided with peripheral bosses is disposed.

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