FR2525957A2 - Foamed polyurethane bored pressure medium adaptor blocks - produced in multi-impression mould with mould pins used as inserts - Google Patents

Abstract

Parent patent mould produced foamed polymer adapter blocks with holes for pressure medium, namely surface channels connected by holes through at right angles. In this addn. the mould pins are now used as inserts, the mould can have multiple impressions ie. produce several blocks at once. Polyurethane is pref. used for the foam. The method eliminates problems of the parent invention e.g. excessive pressure on the ribs to mould the surface channels, or encapsulation of the ends of the pins; visual inspection is enough, the method eliminates need for perforated plates for locating the pins.

Description

Device and method for forming adapter blocks having pressurized fluid channels and method for manufacturing the device "
The invention relates to a method for manufacturing adapter blocks having pressurized fluid passage channels which have surface channels not extending in one surface of the block and connecting holes extending perpendicular to this surface, method in which a foam material with integrated skin is foamed and solidified in a negative ioule of the adapter block and, after the curing of the integral skin foam, the surface of the adapter block which exhibits the surface channels and the connection surface of the adapter block which is opposite this first surface. The invention also relates to the advantageous configuration of the foaming wheel, that is to say of a device which is particularly well suited for the ease of carrying out the above process. This mold is composed of a first mold end part which bears negative impressions for the surface channels of the adapter block1 of a second mold end part which carries receptor housings for cores representing the negatives of the connection bores of the desired adapter block, as well as. of core rods which are embedded in the second end part of the ioule and that of an intermediate part with a strong frame which can be further tightened with a watertight joint between the two end parts of the ioule. Finally, the invention also relates to the rational production of this device.

 The present invention is based on measurements as they are illustrated by the main patent also filed by the applicant. Such an adapter block for pneumatic and / or hydraulic components comprising integrated connections is composed of at least two layers of which at least one layer is made of cough; moreover, in the fist a layer contains conduits presented in the form of channels and / or through holes which cross the layer transversely and end at least partially in a channel; on the block itself, control elements may be mounted or glued (in the static, semi-static, dynamic core); finally, the pressing block means for the connection of fluid conduits such as, for example, fittings for pipe threads, multipolar connection elements, which are, for example glued in the block or on this block, force-fitted or An adapter block is therefore composed of several blocks or plates provided with integrated connections and on which pneumatic or hydraulic elements can be mounted and which have been connected by means of elementary connections or multipole connections to the supply. and / or at the periphery. The manufacturing of the adapter blocks which serve to establish the connection of standardized pressurized fluid connections with active or passive pressurized fluid components is carried out as follows: the foam With skin integrated into a foam of suitable configuration and, after hardening, the connecting surfaces of the adap block are machined This process sl4mine the compact sound, that is to say the region which is immediately added to the foaming foam, is removed so that the surface is now formed by the small structure that under them. -Jacente of the material, which gives rise to a roughness and facilitates the deposition of the adhesive. At the same time1 a flat surface is formed. The connection between the pressurized fluid connections and the pressurized fluid components is obtained by the formation, according to an appropriate mode of surface channels and possibly of connection bores in at least one plate of the block.

This is obtained by an appropriate configuration of the foaming ioule and, in particular, in the case of connection bores, by the installation of core rods in the negative mold, which can advantageously be carried out by arrangement of these rods. in a predetermined template. Previous practical experience has shown that, on the one hand, it was possible to criticize considerably the cost of manufacturing adapter blocks while improving quality at the same time and that, on the other hand, new process developments. manufacturing and mold of moussa go, would make further decisive improvements.

The present invention therefore aims to improve and improve the characteristics described in the main patent filed by the applicant. These efforts concern both measures aimed at perfecting the foaming mold and the manufacture of the adapter block and the foaming mold.
This problem is solved, as regards the improvement of the foaming mold, by the fact that rods are used as core rods, one end of which is produced in the form of an anchoring end. This characteristic widens the tolerance range to be observed for preparation work for the manufacture of the casting mold. Initially, the core rods, which would later give birth in the adapter plate to the connections between the channels and the underlying plane, risked exerting too great pressure on the ribs provided for molding the channels of the negative mold, or not to touch those ribs. In the latter case, this results in the formation of separating skins which had to be eliminated in a separate working phase, so as not to oppose the passage of air subsequently. Not only does the use of such anchoring rods safely remove any rework that may be necessary, but in practice it also eliminates the inspection of foam blocks because the through holes may be missing or incomplete if the mold has an extremely visible deterioration which, from its catie would be recognized automatically and inevitably at the time of the opening of the mold. Remains, this way we eliminate disadvantages which, Up to now, resulted from the fact that the stems had to be put in place in the mold by means of perforated plates, entailing as a consequence an increase in the coat of the press as well as relatively long transformation times. In this case, a separate perforated plate had to be provided for each template and the work was relatively random when it was necessary to form through holes of a section which was different from that for which the gauge was p reviewed,
On the contrary, the anchor bolts are independent of any size and gllas allow to modify in a very convenient way the section of the through openings and their shape.
The invention further proposes to produce the foaming mold so that it is caiupsiee of several adapter blocks, this resulting in consequence the possibility of simultaneously making several adapter blocks in a single pass. The advantage of this characteristic consists in the reduction of manufacturing costs since these are essentially determined by the time spent by the foaming mold in the press. The production of several elementary plates at the same time would eliminate the additional investment for the purchase of other presses. In addition, we would obtain a simplification of storage and handling and we could automatically manufacture a large number of parts from each individual copy.

 In addition, it is advantageous to choose for the total thickness of a plate or a layer approximately 1.5 to 2 times the depth of the channels in the case of surface channels present on a single face and 2.5 3 times the depth of the channels in the case of surface channels provided on both sides. The products produced in this way have sufficient solidity.

 In an advantageous embodiment of the invention, a layer or plate has a thickness of 6 to 8 mm if it has only superficial channels on one side. If, on the contrary, it is provided with superficial channels on the soft faces, the thickness should advantageously be chosen at a value of 10 to 12 mm. The downward limitation results from the flow behavior of the mold mass during its introduction into the mold and during the subsequent swelling which occurs during foaming.

Under the effect of the ridges of the foaming mold which are used for molding the channels, the liquid introduced has only a limited passage section and sudden changes in section occur at the same time. under this effect, higher flow rates and turbulences are inevitably produced, which involves a risk of air inclusions. Practical experience has shown that, in the case of 6 mm thick plates (in general, the depth of the channels is approximately 4 mm) the scrap rate is negligible.

 Comparatively, a plate thickness of 8 mm has other advantages if there is a considerable reduction in the flow speed, it is not necessary to provide a second plate thickness for the assembly carried out with bars. socket connection and the maximum size of the product to be manufactured is increased to 200 x 300 bones or more. An increase in the thickness of the plate beyond the values indicated leads to a considerable lengthening of the manufacturing cycles. An effort must be made to reduce the duration of the cycles to as small a value as possible because it is one of the sensory bone parameters of this manufacturing level. The indications available up to now have concerned only the layers or plates which are provided with superficial channels only on one side. On the contrary, in the case of plates which sense surface channels on both sides, the parameters influencing factors already exposed above give an optimum interval of 10 to ta mm for thickness.

 In one embodiment, it is intended that the negatives of the connection holes have a conical shape.

The advantage of such a characteristic is revealed in particular in the case of the use of a sealing plate - this expression will be explained below - which is provided with tubular formations.

 Furthermore, it is advantageous to manufacture the foaming mold from a plastic material which can be cast, which makes it possible to obtain lower cost prices and greater ease of handling, compared with metal molds. Added to this is the fact that the compact zone has a thin thickness so that, advantageously, it suffices to grind it to obtain a sufficiently rough surface. This surface improves adhesion and widens the tolerances to be observed for the deposition of the adhesive.

 According to another characteristic of the invention, it is proposed to carry out the manufacture of the foaming mold by driving anchor rods of an appropriate length into the holes of the original positive so that, when the negative mold is cast , these rods are embedded in the mass of flowing by their anchoring end. According to a simpler method, the negative mold is manufactured by means of anchoring rods, replacement of the core rods which are generally arranged in a standard template. The use of anchoring rods offers a whole range of advantages, as already mentioned above. It is desirable to carry out the casting of the original mold, that is to say the manufacture of the negative mold under empty, and to provide the angles and arguments of the original positive with a resin to be poured using a brush before casting. This feature prevents bubble inclusions.

 The CHARACTERISTICS proposed in the following relate to improvements in the process for manufacturing adapter blocks having pressurized fluid channels as defined in claims t A 3 of the main patent. First, it is recommended to proceed with the casting of the foam-generating material with skin integrated in the foaming mold from below and / or along a longitudinal side. This has the effect of keeping the flow rate relatively low. , so that there is practically no more fear of turbulence nor, consequently, of risk of air inclusions and that the rate of rejects can thus other maintained at a low level. This method of manufacturing makes it possible to manufacture adapter blocks with a minimum thickness, which is of decisive importance due to the fact that the thickness of the plate or layer largely determines the time of exposure in the press. during manufacturing and the fact that this time has a significant impact on the level of manufacturing coatis. These costs are therefore particularly low when the thickness is reduced as much as possible.

 While the foaming process requires a relatively low closing pressure, around 5 bar, relatively low temperature conditions, maximum 60 C, as well as relatively low flow forces inside the mold, the material special polynrethane proves to be particularly advantageous for different reasons. Polyurethane is very resistant to glycerine and mineral oil, including benzene, as well as vegetable oils and ozone. This material has advantageous mechanical properties: sufficient mechanical resistance and elasticity and the absence of internal tensions, a weak influence of temperature, in particular at low temperatures, and the absence of embrittlement by aging. This results in specifications for the strength of the foaming mold which can be satisfied relatively simply, with a relatively low cost.

 According to the invention, a particularly advantageous embodiment of the process for manufacturing the adapter blocks consists in producing at least one of the connection surfaces so that the fittings and / or components to be mounted on the block can be mounted by means of '' a seal and removing the basic phenolic resin pads that were stuck on the blocks so far.The previous solution fully satisfied deny the specifications from a technical point of view but it had the disadvantage of being relatively expensive because the cost of these basic inserts is about the same as that of the adapter block and, moreover, their presence increases the labor cost by around 5 to 25% . Normally, a sealing plate must be subjected to a relatively high pressure to be fully effective, in particular in the case of certain components. In this case, one is exposed to the risk of seeing the sealing plate producing in the imprint layer. which can lead to leaks after a certain time and, moreover, the mounting screws must find a sufficiently solid anchorage due to the forces exerted.

 The sealing plate can advantageously be provided on both sides with tbular formations, more precisely at the places where the holes open. During the mounting of the sealing plate on an adapter block, the tubular formations then engage in the holes of the adapter block and, in addition or as a variant, in the holes of the component under pressurized fluid which it 8 2a- tit to fix. Here, the tubular formations must be dimensioned so as to undergo an elastic preload after having been engaged in the bores. In this case, it is advantageous that the holes have a conical shape, as has already been claimed. On the one hand, this facilitates the introduction and, on the other hand, the possible defects of pitch do not have 'effect. In response to the application of pressure, the tubular formation is even more strongly compressed against the walls of the conical holes, which leads to an increase in the sealing effect (positive sealing) due to the elastic prestressing of the formations. The tubular shape of the sealing plate and, especially in the case of tapered holes, it is possible to cover in a relatively simple manner the differences in positioning in space of the aligned holes. The conical contiguity of the holes further simplifies the 'introduction of the tubular formations of the sealing plate.

 As materials for the manufacture of the sealing plate, it is advantageous to use, apart from the widely used elastomers such as, for example, perbunan and neoprene, a polyurethane elastomer. This material is able, both to allow relatively small elastic deformations of the tubular formations of the sealing plate and to ensure sufficient stability in the presence of oil, good sliding behavior and a temperature range. relatively broad allowable.

 The invention will be described in more detail below with reference to the drawing which reproduces only one embodiment. This drawing represents in a sectional view a part of an adapter block, with a sealing plate and a component mounted on this plate. In this construction, the reference numbers of the main patent have been used as far as possible, possibly supplementing them.

 In the section shown in the drawing, the adapter block (10), which is advantageously made of polyurethane, has two connecting holes (O, 32) which are conical in shape. Since the adapter block (10) is shown in the assembled state, the drawing also shows the pressurized fluid component (42). This component also has holes (75) which are aligned with the connection holes (32 ) of the adapter block Liter the adapter block (lo) and the component A pressurized fluid (42), there is a sealing plate which is provided on both sides with tubular formations (74), which are dimensioned so as to s 'Engage in the connection bores (30, 32) as well as in the corresponding bores (75) of the pressurized fluid component (42).

Here, the tubular formations (74) are dimensioned so that after having been engaged in the connecting holes (30, 32) of conical shape and in the holes (75), they undergo at their ends a slight pre-stress which initially determines the tightness. In the presence of pressure, the tubular formations (7i) therefore apply directly against the internal walls of the connection bores (30, 32) and the bores (75), so that one can obtaining an optimal and positive seal In this constitution, the seal plate (73) is directly applied to the center of the connection face (34) of the adapter block (10).

 This direct application of the sealing plate (73) A seal on the connection surface (34) of the adapter block (10) or the connection surface of the control element (82) is not necessary. This follows from the fact that with a sufficient material thickness, the tubular formations <74) can cover a limited distance to their root without bursting. The calculation of the material thickness of the tubular formations (74) must therefore guarantee a sufficient mechanical strength At the root of these formations and sufficiently easy deformability at their ends.

 The proposed embodiment which is shown in the drawing allows the use of connection elements which, with the exception of the numbering, are entirely identical in the case of a arrangement of the fittings in a single row.

 The fact that the watertight seal is produced at the ends of the tubular formations (74) substantially limits the forces which tend to separate the component from the block or to separate two connecting elements, to the sum of the free sections of the connections which belong to a item or connection. Not only does the total force action have only a value considerably lower than the pressure forces exerted on a larger surface, which are manifested in the case of conventional seals, but also it represents only a fraction of the force which is necessary to deform the conventional seals enough to be effective in all respects, so the necessary mounting forces are reduced to values that can be easily reached in polynrethane foam by means of plate screws Clamping.

 The polyurethane foaming process was adopted because it was felt that there was a possibility of reducing the cost of manufacturing the mounting plates and blocks with integrated connecting members, and of simultaneously improving the quality. Previous efforts have focused on this use; other possibilities of use are already being revealed, which extend to the manufacture of pneumatic components via the manufacture of protective caps for control units provided with integrated connections.

 The considerations given above are mainly related to the possibility of manufacturing plates of different thicknesses and different formats, the construction of molds and bonding. The following discussion highlights some of the most important points.

 a) Thickness and format of the plates s the initial tests were based on plate thicknesses between 6 and 8 mm The limitation is given by the behavior of the mass to be transformed into foam during its introduction into the mold and during subsequent swelling which occurs during foaming. Compared to the manufacture of conventional elements, such as, for example, shoemakers of similar wall thickness, we encounter special difficulties which result from the relatively high ribs of the mold which are intended for molding the channels: the liquid does not have that of a limited passage (for example thickness of the plate 6 mm - depth of the channels 4 rz 2 mm) and, at the same time, the section presents rapid variations. The great velocities of flow and the turbulences which result from these circumstances contain in themselves the risk of air inclusions.

 According to the current state of knowledge, the following indications can be given: a format of i60 x 220 mm can be produced with a negligible reject rate with a plate thickness of 6 mm (channel depth of 4 mm). One condition is that the pouring takes place from below and along a longitudinal side, in order to keep the speed of the flow at a low value. Naturally, a condition to be fulfilled is that the adjustment quantities calculated at the outset must be met with precision. Similarly, a plate thickness of 7 mi brings the significant advantages, the flow speed is reduced by 33% and it is no longer necessary. to provide a second thickness of plate for mounting blocks having front connection strips with sockets. Given that we have been able to carry the thickness of the plates to 7 mi ltium, nothing stands in the way of this solution. In all likelihood, the maximum size can be carried by hand to 200 x 300 mm (approximately A4) without the setting of the machine or the external conditions becoming particularly critical.

The advantage of using larger formats of plates lies in the fact that the time spent in the press represents a significant proportion of the cost price of the plates. We should therefore obtain a significant reduction in costs if we could foam all the elementary plates in a single work pass, at least for the blocks of small dimensions. In particular, this would not require new investments in the form of additional presses. Furthermore, we would obtain a simplification of the storage and handling of the molds and we could manufacture, from each individual plate, a large number of parts which would be automatically identical. Furthermore, the introduction of a standardized plate thickness of 7 mi exerts a favorable influence on the possibility of simultaneous foaming of all the individual plates in a single pass, in the sense that the shape and the positioning of the core rods (insofar as they are still necessary, see below), are simplified
A plate thickness of more than 10 to 12 mi leads to considerably elongated cycles. It is for this reason that mounting blocks furnished on one side and fitted with front connection bars are frequently fitted with a special lower plate: indeed, if the lower extracted channel plane is at the level of the row bottom of the nozzles, the lower extracted plate must have a thickness of 14 mm, which exceeds the value indicated above. For this reason, on the underside, most of the surface is hollowed out to a depth sufficient for the the remaining thickness now only represents about 7 This should preferably be produced with prefabricated unit elements because, subsequently, during bonding, it is again necessary to have underlying elements to give support
The indications given so far relate to plates provided with channels on only one face t currently, there is no experience on the extent to which the conditions change when one makes use of the possibility, also interesting in many cases , to use plates provided with channels on both sides. It is assumed that the minimum thickness of 10 mm would barely suffice for the maximum format cited last. However, since the thickness of the area which does not have channels can be easily increased to 6 mi, it is possible to assume that it would be possible to produce plates provided with channels on the soft sides and of the aforementioned maximum format in a total thickness of between 10 and 12 mm.

b) Construction of the molds: the polyurethane foaming process offers the best conditions for an advantageous manufacture of the molds
1. Low closing pressure required, around 5 bar
2. Low temperature requirements r maximum 600C and
3. Low flow force inside the mold.

Owing to this situation, in fact, the actual molding elements can be produced without difficulty from plastics to be cast, so that, compared to metal molds, there is still obtained the shrinking of a small thickness. the compact zone in the case of an integrated skin foam. The small thickness of the compact zone is advantageous in that only a small thickness has to be removed by molding in order to obtain a porous surface. This allows large tolerances to be adopted when depositing adhesive and improves the colla go. From the beginning and until recently, universal molds have been used exclusively. The corresponding process is the subject of a patent application where it is described in detail. The advantage lay in the absence of risks and in the precision of the positions of the holes present in the plates formed by foaming. The disadvantage lies in the relatively long tool transformation times and in the increase in the cost of the press which results from the perforated counting plate and the numerous rods. In addition, for each gauge (for example in the system t 000, Mfit etc ...), a separate perforated plate must be provided and the use of elements having different basic templates on one and the same block can only be carried out without special provision on one side of a block fitted on both sides. Finally, there are additional difficulties when it is necessary to provide through holes with a section greater than that which corresponds to the gauge used (the sections of the channels can naturally be always chosen at will).
The most recent development consists in working with a mold construction in which the holes made in the channel plates are produced by rods which are fixed in the mold plate. To this end, rivets of an appropriate length are driven into the holes of the original positive and, during the casting of the negative mold, these rivets are embedded by their test in the mass being cast.

 This process eliminates on the one hand all the disadvantages already mentioned of the initial process and, on the other hand, it allows to adopt wider tolerances during the preparation work for the manufacture of the casting mold. Indeed, initially, there was the risk that either the core rods placed in the foam plate exert too great pressure on the ribs present in the negative mold for molding the channels, or that they do not touch these ribs. the second case, the consequence would be the formation of separating skins which would prevent or hinder the passage of air if they were not removed during a separate work phase.

 Not only does the new technique avoid with certainty any rework that may be necessary but, in practice, it even avoids the inspection of foamed sheets since the through holes cannot be missing or Other incomplete only if the mold has an extra visible defect . Such a defect would be automatically and inevitably recognized when the mold is opened.

 Other experiments have shown that it is possible to mold directly into the plates by foaming the throttles and ejectors provided for approximately t to 6 bars, and of very small diameter of at least 0.5 mi, by fitting corresponding rods. . A mold fitted with a rod of this nature resisted without difficulty the molding of a series of fifty pieces.

 The volumes intended for the distribution of the supply air, or even to extend the times of the timing devices can be formed by foaming without difficulty when this is provided for a network of coherent channels, for example a multiple network . In this case, the width of the channels should not be greater than the thickness of the plate and the solid parts should have a minimum width of 2.5 mi and make it possible to obtain a proportion of bonding surface of at least minus 25%. At least in the case of the formats used up to now, the extraction of the plates formed by foaming from their molds, with the channels and the rods, is carried out using the conical edge of the frame plate as well as, probably, thanks to what can be called the bonding of the foam plate on the base plate of the press, which is due to the presence of the release agent and which only acts during a short time.

 c) Manufacture of the original mode and casting of the molds: the manufacture of the original model does not present any particular difficulty: the milling of the channels and the drilling of the holes is carried out advantageously by optical guidance from a scale drawing about 2: i, on an engraving machine. The pneumatic remote control for lowering the cutter with the possibility of adopting an automatic mechanism for drilling the holes proves to be advantageous.

 Delrin plates have been found to be the most suitable starting material because this material allows a high speed of advance, it does not oppose significant resistance to the movement of the pantograph and it gives rise to very clean canal surfaces and edges. Another advantage that may be mentioned is that, during the subsequent casting of the negative molds by means of a casting resin of the polynrethane type (with two components), the Delrin does not require a release agent.

 Whereas, for the initial process, pre-printed templates were used on a special paper undergoing only variations in length as small as possible in the presence of variations in humidity and temperature, it is used for the new technique of preprinted connection diagrams with assembly plans for the components used. Thanks to their small format, large variations in relative length can be allowed for these pre-prints; however, as in the prior art, they should be mounted on a support as invariant as possible.

 The original mold must be poured under vacuum to avoid the formation of bubbles. In critical places, if necessary, apply a resin to be poured in with a brush, to avoid air inclusions.

 From an original model, repetitive molds can be poured. In all likelihood, we should be able to obtain more than one hundred copies. According to the format, the cost price of a casting reaches about 80 DX to iao DM. Based on current experience, a minimum lifetime of 200 to 300 foam plates is expected for a mold casting.

 d) Sealing device: the current state of development seems to be far from the objective which may have been achieved. On the one hand, the properties of the material used up to now are not recognized as still good enough to realize without risk, possibly, ideas that exist and can Other implemented today, one regarding the simplification of the construction of blocks with integrated link and, on the other hand, we already have concrete ideas on the way in which a further reduction in cost price could be achieved by modifying the sealing device for a new generation of elements and connecting parts.

 Up to now, we have stuck on the blocks basic plates in phenolic resin, special for the elements to be assembled. Over the whole of the temperature range in question, the plates undergo no deformation under the effect of the forces which are developed in the direction of the screwing of the elements. At the same time, the tensile forces exerted by the mounting screws are distributed over a relatively large area.

 However, this solution, which is interesting from a qualitative point of view, is relatively expensive: the costs of the basic plates are about the same order of magnitude as the foam plates and, moreover, their use increases the labor costs. still works about 5 to 25%.

 At present, there is hope, but still no certainty, to be able to dispense with basic platelets.

The main obstacle which opposes it lies in the fact that the seal, especially that of the MA5 elements, must otherwise be subjected to a relatively high pressure for another fully effective. On the one hand, this entails the risk that the seal may form imprints in the foam plate and therefore lead in the long run to a leak due to the reduction in the application pressure, d On the other hand, it is necessary that the mounting screws find in the polyurethane plates a mounting sufficiently solid to correspond to the forces exerted.

Currently, the tests undertaken so far are not yet conclusive; it has been shown that 2.9 clamping plate screws already have sufficient strength at a screw depth of about 6.5 mm in the foam to break under the effect of a force of traction too high. However, stability is not known, especially over a relatively large temperature range, and for a relatively long time. The observation is valid for the impressions resulting from the rubber seals
The purely pneumatic forces which tend to separate an element from the mounting plate are relatively small. If we consider four pressure fittings with a cross-section of 12.5 2, only a force of 30 X is manifested at a pressure of 6 bars. A force of this order of magnitude, distributed over two screws, can be mastered without problem over an extended period. The question is therefore to realize a possibility of mounting and sealing for a pressure force which exceeds the upper value only to the lowest possible extent. Both the element to be mounted and the base plate have clearly conical holes in which the tubular formations of the sealing plate are engaged. The diameter of these tubular formations is calculated so that there is a slight prestress, in the elastic range in the terminal region of these formations, after their introduction into the conical bores. When the connection considered is stressed by pressure , the tubular formation expands, it is pressed more strongly against the wall of the conical bores and thus improves the sealing effect (positive sealing effect).

 The conical configuration of the holes is of interest in several aspects: firstly, this configuration facilitates the introduction of the tubular formations of the sealing plate; then there is an elastic prestressing area which is not excessively large and which varies according to the position in the tolerance range, and finally, it is possible to cover in this way the differences in division pitch without elastic deformation of the plate sealing or only with a slight elastic deformation of this plate.

 The tapered holes can be formed directly in the polyurethane plates during the foaming process, and the same is true for the core hole holes for the fixing plates or for the Parker screws used to fix the control elements . Naturally, the baffles necessary to ensure that the elements can only be placed in one orientation will also be molded during the foaming process.

 Since the tubular formations of the sealing plate only have to undergo a slight elastic deformation, a polyurethane elastomer can be used as the material for the sealing gasket. The advantageous characteristics of this elastomer are the resistance to the action of the oil, the good sliding behavior and the relatively large admissible temperature range.

 The sealing device shown in the drawing is also suitable for multipole connecting elements. For a multipolar connection with 22 blades, 22 male sockets and fittings are replaced, provided with the corresponding O-rings and 44 stop rings, by 44 simple male fitting fittings, of the type of elements 207 339 or 215 579, these fitting fittings being put in place during the molding of the connection strips by injection or by compression. Apart from the number of connections, the two sides of a multipole connection are identical and can only be fitted in one way, however.

 There are already currently, in the form of socket bars P and i, connection elements with 22 connectors, which can be connected and sealed, in all likelihood, by an inexpensive elastomeric seal, as proposed. . This is how, for example, the 96 double male fittings each provided with two O-rings, the 5 retaining tabs and the 10 special screws, which are still currently required to connect the universal connection plate to the slide-out control drawer step FS-10 and to the power supply / display module, and for the connection of the function plug-in plate, can be replaced by only 5 gaskets of this kind. The same observation applies to the connection of plates with program plug-in (for example on the order of programmable commissioning devices) which require 22 or 44 double male fittings with all their accessories.

 However, with regard to the perspectives thus offered, it should not be forgotten that, particularly when developing a new set of control elements, many other conditions must still be fulfilled to facilitate the study and manufacture of blocks mounting with integrated links. This problem can only be solved in close and long-term collaboration between the development departments of control components and those of the integration technique.

 Finally, it should also be emphasized that it would be wrong to limit the foaming technique to the manufacture of channel plates. A first breakthrough has already been made outside the initial field of use by making polyurethane foam with skin integrated, on the one hand the accumulator volume in the power supply / display module for step-by-step control and, on the other hand, a case for a control block comprising integrated connections. The two solutions prove to be very economical, in particular in terms of the cost price of the molds and they have, apart from a remarkable solidity, a total absence of corrosion.

 In order to be able to absorb the cost price of molds for shoemakers even better, research has already been undertaken to standardize, at least in groups, the formats of control circuits with integrated links, so that the same shoemaker can be used for several circuits different.

 Tests carried out at temperatures down to below -28C have shown that no appreciable wetting occurs, which also applies to the channel plates. The test pieces presented only insignificant imprints, without cracking or bursting phenomenon, after having been projected in the cooled state on stone slabs. The bonding areas also remained intact.

Claims (4)

- CLAIMS 1 - Foaming mold for the manufacture of adapter blocks having channels of pressurized fluids, which has surface channels s extending in one surface of the block and connecting bores which extend perpendicularly to this surface, in accordance to one of claims 5 to 10 of the main patent, characterized in that the core rods (58, 60, 62) are anchoring rods.  2. - Mold according to claim 1, characterized in that the foaming mold is composed of several adapter blocks (10).  3. - Swell according to one of claims 1 and 2, ca characterized in that the total thickness of a plate or layer represents approximately t, s at 2 times the depth of the channels for the case of surface channels on one side and 2.5 to 3 times this Depth for the surface channels provided on both sides.  4. - Mold according to one of claims t to 3, ca acterized in that the plate or layer having superficial channels (38, 40) on one side has a thickness of 6 to 8 mm.  5. - A mold according to any one of claims i to 4, characterized in that the plate or layer having surface channels (38, i0) on both sides has a thickness of 10 to ta mm.  6. - Mold according to any one of claims t to 5, characterized in that the negatives of the connecting holes (28, 30, 32) have a conical shape.  7. - Mold according to any one of claims i to 6, characterized in that the foaming mold is composed of plastic material moldable by casting.  8. - A method of manufacturing the foam mold according to any one of claims i to 7, characterized in that the rods are anchored with an anchor of an appropriate length in the holes of the original positive and that then, we manufacture the negative mold by casting in such a way that the anchoring rods are embedded by their rods in the casting mass  9. - Method according to claim 8, characterized in that the casting of the negative mold is carried out under vacuum  10. - Method according to one of claims 8 and 9 characterized in that before casting, a resin is deposited to be poured into the corners and the edges of the initial positive.  tt. - A method of manufacturing adapter blocks according to any one of claims 1 to 3 of the main patent, characterized in that the casting is carried out in the foaming mold from below and / or along the longitudinal side of this mold.  12 - Process according to claim tt and / or according to any one of claims t to 3 of the main patent, characterized in that, for casting, polyurethane material is used.  13 - Method for manufacturing adapter blocks according to any one of claims tt and t2 and / or according to claim t of the main patent, characterized in that a sealing plate (73) is mounted on the surface (s) ( s) connection (ta, 34).  14 - Method according to claim i3, characterized in that the sealing plate is provided with tubular formations (74) which project on one side or on both sides and which engage in the connection holes (30, 32).  15. - Method according to claim 14, characterized in that the tubular formations (74) are dimensioned in such a way as to be subjected to an elastic preload after having been engaged in the connection bores (30, 32)  16 - Method according to one of claims 12 to 14, characterized in that one uses for the sealing plate (73) a polyurethane elastomer.