FR2670267A1 - FLEXIBLE-TUBE CONNECTION, AND METHOD FOR ESTABLISHING THE SAME. - Google Patents

Abstract

In a connection between a hose and a tube, a sealing material (4) interposed between said hose (3) and said tube (1), at least in the region between a retaining rib (2) of the tube and a clamp (5), retains its sealing ability in a temperature range at least between - 40 ° C and + 140 ° C.

Description

i

  FLEXIBLE-TUBE CONNECTION, AND METHOD FOR ESTABLISHING THE SAME

  The present invention relates to a flexible connection

  tube, in which the tube is provided with at least one retaining rib near its end, and the hose is

  threaded on the tube by an extreme region, beyond the nerve

  retainer, then is clamped firmly with a collar

  hose clamp or the like surrounding the hose

  laugh the retaining rib; as well as a process for

blir such a bond.

  In a known flexible-tube connection of this type, in

  which hose consists of an ethylene terpolymer-

  propylene containing a woven inclusion, and the tube consists of a metal, the connection loses its tightness in particular at low temperatures located below the freezing point,

  and under strong internal pressure Experiments

  In a wide range of temperatures and fluid pressures, it can be concluded that, when the temperature drops, the contraction of the material constituting the hose

  results in a loosening of said hose in the region if-

  killed between the clamp and the tube, that is to say that

  the thickness of the material constituting the hose ends up

  cuse a decrease so strong that this material does not exert

  no more back pressure on the hose clamp This collar

  binding is therefore ineffective and, although the hose is

  tightens more firmly around the tube, due to its con-

  traction, it can nevertheless also be flared radially in the vicinity of the collar, when the fluid pressure increases in this hose insofar as its elasticity has not been degraded by cooling -, so that the fluid

  pressurized can escape between the tube and the flexible Cer-

  tes, the material of the hose expands when the

  temperature increases, so this material is particularly

  bind more strongly pressed in the region of the clamp

  ge, from the fact that its volume increases; however, the effect exerted by the high temperature (notably exceeding 900 ° C.) and by a

  strong squeezing pressure can result in deformation

  tion, and therefore by a lack of elasticity of said flexible material, from which it follows that the tightness of the connection also decreases in an average temperature range.

  The object of the invention is to provide a flexible connection

  tube of the aforementioned type, as well as a method for establishing this connection, both having the effect of ensuring a sufficient seal in a higher range of temperatures and

fluid pressures.

  According to the invention, in the flexible-tube connection

  of the type considered, this object is achieved by the fact that a ma-

  sealing material interposed between the hose and the tube, at least in the region between the retaining rib and the clamp, retains its sealing ability at least in a temperature range between 400 C and

+1,400 C.

  Because in this solution the waterproof material

  ment is also located in the axial direction, outside the clamping area of the clamp, the tightness of

  the connection is independent, outside the area of enser-

  rement, of the clamping force applied by said collar Therefore, if the material constituting the hose contracts when the temperature drops, this contributes to sealing

  sufficient, also when the fluid pressure increases

  pectively in the flexible or in the tube, because the presence of the sealing material makes it possible, overall, to have

  more material between the clamp

  rage and the retaining rib The connection likewise retains its tightness in the event of excessive heating: on the one hand to

  because the material of the hose expands

  te in the clamping zone of the collar, with increase

  of its volume, thereby increasing the force to teach-

  rement; and, on the other hand, due to the fact that there is, in the region between the collar and the retaining rib, a greater amount of material which expands upon heating, and increases the pressure sealing

in this region.

  The sealing material is preferably endowed with elastic-

  ticity If the pressure of the medium fluid increases

  flaring the hose when the temperature is constant

  aunt, the elasticity additionally contributes to ensuring a

  tightness due to the fact that, where appropriate, the waterproofing material

  elastically relaxes and thus continues to maintain a filling of material in the intermediate space located between the hose and the tube, in particular in the intermediate space

  adjacent to the base of the retaining rib, without any

terstice neither remains nor is born.

  In addition, it can be made so that the material

  does not adhere to the hose This hose can

  subsequently, if desired, be more easily removed from the tube after loosening the collar -, since the surface generally available for adhesion between the hose and the tube, which can be frequently observed in the long run, is

consequently smaller.

  When the sealant is placed throughout the region between the retaining rib and the end of the

  flexible, this flexible no longer has any adhesion surface

  rence on the tube The hose can therefore, if desired, be removed even more easily from the tube (after

loosening the collar).

  In addition, it is advantageous that the sealing material is an adhesive adhering only to the tube. This has the effect of ensuring an even greater seal since pressurized fluid could not escape, at the very least,

  between the tube and the sealing material.

  Preferably it is made so that the material

  either deposited in a viscous state on the tube, and either

  hardened on this tube In this case, the material

  sealant is applied to the tube in a special way

  completely waterproof, while also compensating for surface roughness of said tube, such as mold release burrs,

  in particular axial release burrs Machining, in part

  particularly a deburring of the tube surface, therefore proves

  quent superfluous. It can, moreover, be made so that the hose consists of EPDM or of silicone rubber, in particular with a woven inclusion, that the tube consists of a metal or of a plastic material, in particular a polyamide, and that the sealing material consists of synthetic rubber,

  in particular a silicone rubber, or a fluorinated elastomer.

  This provides particularly pro-

  parts for hose, sealant and tube.

  The method according to the invention, for establishing the connection

  its, consists in that the sealing material is deposited in the viscous state near the retaining rib, in the form of an accumulation of material surrounding the tube between the

  retaining rib and the clamping area of the clamp

  rage, at least up to the radial height of said retaining rib, and in that the hose is threaded on the front tube

  hardening of the sealing material, beyond the

  retainer and said sealing material In this pro-

  yielded, viscous sealing material facilitates threading

  hose on the tube At the same time, the sealing material

  ment is distributed practically over the entire length of the section of the hose situated between the retaining rib and the threaded end of said hose, without being for the most part repelled

  in front of the end of the hose after it has been threaded

deny.

  A variant of the method for establishing the connection can

  sister in that the sealing material is deposited on the tube in a shaping tool which surrounds said tube, the hose being threaded after the curing of said material

  This authorizes a prior assembly of the connection

  sound, for example when the tube is constituted by a tubular connection whose fixing must take place only on

installation site.

  The invention will now be described in more detail at

  title of examples in no way limiting, opposite the drawing an-

  nexé on which: Figure 1 is a fragmentary illustration, partial-

  ment in axial section, of the tube and hose of a flexible connection

  xible-tube according to the invention, prior to threading

  hose on the tube and with a viscous waterproof material-

  ment accumulated next to the retaining rib of said tube, FIG. 2 is a half-section of a flexible-tube connection according to the invention, in the completed state,

  FIG. 3 is a fragmentary representation of a va-

  laughing of the flexible-tube connection according to FIG. 2, comprising

  both two retaining ribs instead of one; and FIG. 4 shows another variant of the process according to the invention for depositing a viscous sealing material,

  on the tube, using a shaping tool.

  According to Figures 1 and 2, a flexible tube-connection

  form of the invention comprises a tube 1 provided with at least one

  retaining rib 2 at its end; a hose 3; a My-

  sealing material 4; and a locking clamp 5 which consists of a clamping tape 6 with clamping jaws

  7, as well as a clamping screw 8.

  The sealing material 4 is a silicone rubber

  which retains its properties, and therefore also its ability to

  dearly, in a temperature range between about

  800 C and around + 2600 C It can be a rubber if-

  hot cross-linking liconé, which is vulcanized at 200 ° C with peroxides However, it is also possible to use

  cold vulcanizable silicone rubbers

  cold channel pasty and free intermediate products

  of solvents, taking the form of two-component masses which

  closing specific crosslinking agents, or

  mass of a component which crosslinks by the influence of air.

  In the present case, it is a dimethylpolysiloxane asso-

  linked to a crosslinking agent and to specific filler substances. The tube 1 consists of a metal, and the hose 3 consists of an ethylene-propylene terpolymer (EPDM) containing a

woven inclusion.

  According to FIG. 1, the sealing material 4

  is deposited in a viscous state near the rib of re-

  outfit 2, in the form of an accumulation of material surrounding

  the tube 1 between the retaining rib 2 and the wedge area

  clamp 5, at least up to the height

  dial of said rib 2, preferably substantially more

  top In the sequence, the hose 3 is threaded on the tu-

  be before the sealing material 4 has hardened, beyond the retaining rib 2 and of said material 4, as illustrated in FIG. 2 The clamp 5 is put in place

  place and blocked after hardening However, it is also

  LEMENT POSSIBLE TO PLACE AND LOCK SAID COLLAR BEFORE CURING When threading the hose 3, the sealing material 4 is distributed to form a thin film which extends over the entire region between the rib 2 and the end of the hose but which however still has a thicker accumulation in the groove formed by said

  rib 2, between this rib 2 and the collar 5 After hardening

  cementation, the sealing material 4 forms a rubber if

  liconé endowed with elasticity, whose adhesion is relatively

  closes on the outside of tube 1, but barely feels

  visible on the inside of the hose 3.

  The tube 1 is materialized by the connection sleeve

  to the radiator of the internal combustion engine of a motor vehicle

  mobile, and the hose materializes the cooling water hose

  interposition between the radiator and the engine block.

  When the temperature of the flexible tube connection drops

  up to below freezing point (engine stopped in half

  worm), the material constituting the hose contracts (with reduction in its volume), so that the clamping force of the collar without the sealing material 4 would disappear

  lack of back pressure, and that the flexible 3 would be

  just loose between tube 1 and collar 5 Now, however

  dant, the connection remains tight even if the engine is started and if the pressure of the cooling water increases even before this cooling water has warmed up This is due to the presence of the sealing material 4, in

  particularly in the region between the collar 5 and the nerve

  retaining level 2: indeed, even at a very low temperature

  re at which the hose material is almost hard, it

  still retains its elasticity, maintains to a large extent

  on the clamping pressure in the vicinity of the collar 5, and expands radially with relaxation due to its elasticity

  preserved, in the region between the collar 5 and the ner-

  vure 2, with flaring of the hose 3 following the pressure of the

  increasing fluid, so that it continues to provide a tight

  sufficient chewiness The elastic expansion of the sealing material

  chement is then maximum in the region between the collar 5 and the rib 2, because said material 4 has its

  greater thickness in this area.

  An increase in the cooling water temperature

  dissement also implies a heating of the bond De

  this fact, the material constituting the hose expands again

  calf, so that the clamp 5 applies again

  greater clamping force and sufficient sealing

  health is ensured at least in the area around which said collar 5 is clamped, even if the hose 3 is lifted substantially away from the retaining rib 2, in the radial direction, by

increasing internal pressure.

  As long as the sealing material 4 is vis-

  that it compensates for all the surface roughness of the tu-

  be 1, in particular axial demoulding burrs, which dispenses with machining of the surface of said tube 1 In addition, said material 4 adheres firmly to the surface of tube 1, so that, even when there is a very low temperature, the pressurized fluid cannot escape between said material

4 and said tube 1.

  The embodiment according to FIG. 3 differs from that of FIGS. 1 and 2 only by the presence of two retaining ribs 2 and by the fact that the sealing material is deposited in the viscous state, between the rib

  retaining 2 axially internal and the respective corner area-

  cement or clamping of the clamp 5, with accumulation as in the embodiment according to Figure 1

  in this case, the groove or groove located between the two ribs

  res 2 is used mainly to collect material

  excess sealing line 4 ′ which, after the hose 3 has been threaded onto the tube 1 and after the collar 5 has been blocked, is pushed back towards the end of said tube 1 before having hardened, opposite to the direction d threading of said flexible hose 3, so that it does not reach the considered internal space of said

flexible 3 or of said tube 1.

  FIG. 4 illustrates, diagrammatically, a variant of the method intended for depositing the sealing material.

  uses, in this case, a tool 9 for molding or shaping

  me which is largely adapted to the configuration of the tube 1 and to the desired configuration of the hardened material 4, and has circumferential cutting edges 10 and 11 serving to ensure axial sealing; for demolding, tool 9

  then consists of two halves and is coated, on its underside

  dull, of a material preventing adhesion between this tool 9 and the sealing material 4 This material 4 is injected into

  tool 9, in the viscous state, through a discharge orifice

  not illustrated It then remains in the mold until

  that it has hardened At the end of demolding, the hose 3 is

  spun as in FIG. 2, then the hose clamp 5 is put in place and locked around said hose 3 This variant allows the connection to be mounted beforehand when the tube 1 consists of a connection sleeve fixed for example to a

  later stage, at a water pump.

  In all the cases considered, the tube 1 can also consist of a tubular piece of hose coupling, which has at least one respective retaining rib 2 at each end, and is used for securing

two hoses.

  Other modifications of the illustrative examples illus-

  very may consist, for example, in that the hose is also made of silicone rubber containing, in particular, a woven inclusion In addition, the tube can be

  made up not only of a metal, but also of a ma-

  plastic and in particular of a polyamide In addition, the material

  sealant may consist of another syn-

  thetic or in a fluorinated elastomer, for example one of the elas-

  tomers sold by Du Pont de Nemours, under

  the trade name "Teflon" or "Viton".

  It goes without saying that many modifications can be made to the invention as described and shown,

without going beyond its framework.

Claims (10)

-R E V E N D I C A T I O N S-   1 Flexible-tube connection, in which the tube (1) is provided with at least one retaining rib (2) near its end, and the flexible (3) is threaded on the tube (1) by an end region , beyond the retaining rib (2), then is clamped firmly by means of a clamp (5)   or similar element surrounding the hose (3) behind the nerve   retaining frame (2), connection characterized in that a ma-   sealing material (4) interposed between the hose (3) and the tube (1), at least in the region between the retaining rib (2) and the clamp (5), retains its sealing ability 4 ' ai: less in a temperature range between 40 'C and + 140' C.   2 connection according to claim 1, characterized by   that the sealing material (4) is endowed with elasticity.   3 Connection according to claim 1 or 2, characterized in that the sealing material (4) does not adhere to the flexible (3).   4 Link according to any one of claims 1 to   3, characterized in that the sealing material (4) is arranged throughout the region between the rib of   retainer (2) and the end of the hose.   Link according to any one of claims 1 to   4, characterized in that the sealing material (4)   is an adhesive adhering only to the tube (1).   6 Connection according to any one of claims 1 to   , characterized in that the sealing material (4) is deposited in the viscous state on the tube (1), and is stopped by hardening on this tube (1).   7 link according to any one of claims 1 to   6, characterized in that the hose (3) consists of   EPDM or silicone rubber, in particular with an   woven, the tube (1) consists of a metal or a plastic, in particular a polyamide, and the sealing material (4) consists of a synthetic rubber, in particular a rubber   silicone, or a fluorinated elastomer.   8 Method for establishing the connection according to claim   6 or 7, process characterized by the fact that the sealing material   (4) is deposited in a viscous state near the nerve   retaining bar (2), in the form of an accumulation of material surrounding the tube (1) between the retaining rib (2) and the clamping zone of the clamp (5), at least up to   the radial height of said retaining rib (2), and the   xible (3) is threaded on the tube (1) before the sealing material (4) hardens, beyond the retaining rib   (2) and said sealing material (4).   9 Method for establishing the connection according to claim   6 or 7, process characterized by the fact that the sealing material   is deposited on the tube (1) in a setting tool (9)   in shape which surrounds said tube (1), the flexible hose (3) being   spun after hardening of said sealing material (4).