EP0637473B1 - Device for crimping a metallic ring to a cilindrical body and its use for fixing a flexible conduit for an automobile vehicle engine - Google Patents

Description

The invention relates to a crimping device a metal ring on a cylindrical body, adaptable to parts of variable diameter and whose operation is perfectly controlled.

Various industries, especially industry automotive use crimping devices metal rings on a cylindrical body and in particular on a flexible connection pipe such as rubber or plastic conduit in the circuit for cooling a motor vehicle engine. The fixing by crimping of metallic annular parts on a connecting pipe is used for example to make a tight connection between the flexible duct and a rigid tubular tip which can be for example integral with the radiator of the motor vehicle.

Such joining devices can be also used to connect the device ducts for heating the passenger compartment of the vehicle.

In published patent application FR-A-2,704,296 after the filing date of this application, it has been proposed such a sealed junction device between a flexible conduit and a rigid tubular end piece and installation mounting of this device. The device Junction has an outer ring and an inner ring between which the connection end of the flexible duct, a seal and a clip for retain the end of the conduit on which the rings are crimped onto the rigid end piece.

The device mounting installation includes in particular a crimping unit comprising a frame fixed, crimping jaws mounted mobile on a support integral with the frame and a jaw displacement cylinder, so that they come together to perform the crimping. The jaws are also moved in the opposite direction to ensure the loosening of the parts which have just been crimped, via elastic return pieces or springs.

To crimp rings on flexible hydraulic circuits for high pressure (50 to 200 bars), we generally use crimping systems offered by manufacturers machines for various uses and for crimping of parts with a very different structure that of vehicle cooling fittings automobiles, for example rubber tubes having internal metal cladding.

These installations are therefore not perfectly suitable for crimping small diameter flexible conduits such as cooling system conduits of motor vehicles. In particular, these machines do not provide perfect amplitude adjustment movements of the clamping jaws and precise steering of the forces involved during the crimping.

In addition, the crimping systems according to the prior art does not allow very easily and very quickly adaptations to pieces of variable diameters.

In the case of applications in the field of automotive construction it may be necessary to perform successively crimping series of parts with different diameters.

It is therefore desirable to have facilities which can be quickly modified and adapted to a new part diameter.

In GB-A-2,059,840, a device is proposed crimping according to the preamble of claim 1 comprising a fixed cylinder body which carries removably jaw actuation means, a jaw support being removably mounted on the cylinder rod which is movable relative to the body of cylinder. This device, because the jaws and their support are attached to the movable cylinder rod and because it does not has no means of precise adjustment of the conditions of the crimping, does not guarantee operation perfect, after a change of the crimping jaws.

The object of the invention is therefore to propose a device for crimping a metal ring on a cylindrical body, adaptable in diameter, comprising a fixed frame, a crimping block itself comprising a jaw support, at least two jaws mounted mobile on the support towards each other to perform the crimping and in reverse for loosening the jaws, the support constituting with the jaws a crimping block removable and a jaw displacement cylinder, to realize crimping, via an actuating means having an actuating surface intended to engage with a corresponding surface of the jaws for their displacement in a radial direction of the support, this device can be easily adapted to rings and cylindrical bodies of variable diameter and being equipped with a device for precise adjustment of the conditions of crimping.

For this purpose, the crimping device according to the invention is characterized in that the jaw displacement cylinder comprises a cylinder body of movable tubular shape and a piston secured to a cylinder rod fixed to the frame, the body of a cylinder defining a chamber in which the piston is engaged and being mounted sliding on the piston and on the cylinder rod,
that the support of the generally cylindrical crimping jaws is fixed on the frame in a removable manner in the axial alignment of the rod of the jack,
that the jaw actuating means is removably attached to one end of the cylinder body for the movement of the jaws in the radial direction of the support, by displacement of the cylinder body in the axial direction, and that the crimping device comprises moreover a force sensor interposed, in an axial direction space, between the crimping block and the cylinder rod and a displacement sensor fixed to the fixed frame comprising a feeler element cooperating with a stop integral with the cylinder body.

In order to clearly understand the invention, we will now describe, as an example, by referring to the appended figures, an embodiment of the crimping device according to the invention and its use to crimp a ring external on a flexible connection of a cooling circuit of a motor vehicle.

Figure 1 is a sectional view of a fitting for flexible duct of a cooling circuit, such that described and claimed in patent application FR-A-2,704,296.

Figures 2A and 2B are sectional views axial of a following crimping device an embodiment of the invention, in the loose position and in the crimp position, respectively.

Figure 3 is an enlarged sectional view scale of the removable crimping block of the crimping shown in Figure 2.

In Figure 1, the part is shown end of a flexible conduit engaged between a ring external and an internal ring, before crimping the conduit flexible between the two rings, by deformation of the ring external, in a crimping installation.

The end portion of the flexible conduit and the external and internal rings are part of the elements of the waterproof junction device described in the French patent application FR-A-2,704,296.

The flexible conduit 1 can be a conduit in rubber or other elastomeric material constituting a hose from a cooling circuit of a motor vehicle.

The outer ring 2 has an inner diameter substantially equal to the nominal diameter of the duct flexible 1, in the non-deformed state, in its posterior part 2a inside which the flexible conduit 1 is engaged up to come into abutment on legs or lugs 3 constituted each by a part of the wall of the ring 2 pushed inward.

The inner ring 4 has a diameter substantially equal to the nominal inside diameter of the duct flexible in the undeformed state, in its part which is engaged inside the flexible duct 1.

The inner ring 4 has a housing in which is arranged a seal 5.

In Figure 1, there is shown the conduit flexible 1 and the rings 2 and 4 in their front position crimping of the flexible conduit 1 between the rings 2 and 4, by deformation in radial compression of the outer ring 2, in its anterior zone 2a engaged on the surface outside of flexible duct 1.

The radial compression forces required to crimp the outer ring 2 have been conventionally represented by arrows 7.

The position of the internal surface of the part 2a of the ring 2 after crimping has been shown on the Figure 1, by the dotted lines 2'a.

As described in the French patent application FR-A-2.704.296, after crimping the outer ring 2 on the end of the flexible conduit 1 bearing on the ring internal 4, a clip is engaged in the slots such that 6 crossing the wall of the outer ring 2 following part of its circumference.

The assembly formed by the end of the conduit flexible, rings 2 and 4 fixed by crimping and clip inserted into the slots 6 is engaged on the end part of a rigid end piece comprising a part projecting radially outwards which is intended to cooperate with the clip to ensure the retention of the outer ring 2 on the rigid end piece. The seal 5 comes to bear on the outer surface of the nozzle rigid, so as to ensure a tight junction.

Vehicle cooling systems modern designed automobiles are subject to service, at an internal pressure of the coolant which is much higher than atmospheric pressure, however, this pressure is generally less than 4 bars, the corresponding coolant temperature being of the order of 117 ° C.

It is therefore necessary to provide a junction resistant and perfectly sealed between the conduits cooling system hoses and connection which are for example integral with the radiator of the vehicle. To ensure perfect safety of the junction, it is necessary that the crimping of the ring external on the flexible duct bearing on the ring be carried out in such a way as to ensure perfect held when the cooling circuit is subjected to its working pressure.

We know crimping machines allowing assembling flexible pipes to metal parts annular, these pipes must resist very high pressures of the order of 50 to 200 bars. These crimping devices which are caused to respond to a entirely different problem from that of the crimping of engine cooling circuits motor vehicle are poorly suited for crimping parts as shown in Figure 1.

Known machines are rarely adapted to case of the crimping of flexible conduits such as engine cooling system ducts.

In addition, the known machines are hardly adaptable to the production of parts that can present variable diameters.

In FIGS. 2A and 2B, a crimping device generally designated by the reference 10 which can be associated with an installation of assembly as described in FR-A-2.704.296 and which is suitable for crimping the outer ring of a junction device as shown in Figure 1.

The device 10 comprises a fixed frame 11 which may consist of part of the installation frame mounting, a removable crimping block 12 comprising mobile crimping jaws and a displacement cylinder 13 jaws of the crimping block between a position loose and a tight crimp position, by through an actuating means 14 of form annular.

In FIG. 2A, the elements of the device 10 have been shown in the jaw open position and in FIG. 2B, in the crimp position by jaw tightening.

The actuating cylinder 13 comprises a rod cylinder 15 of tubular shape which is fixed to the frame 11 and which carries the piston 16 of the cylinder mounted inside a chamber 17 formed inside the cylinder body 18 of annular shape.

The cylinder rod 15 of tubular shape comprises two guide bearings 19a and 19b in its bore internal. A nut sleeve 20 is screwed in 19c to the block of removable crimp 12, so that the sleeve nut 20 and cylinder rod 15 are rigidly secured of the frame 11.

The piston 16 is screwed onto a threaded part of the outer surface of the cylinder rod 15 until it comes in abutment on an annular projecting part of the rod cylinder, so that the piston 16 is fixed on the actuator rod 15 and secured to the frame 11. The tightness between the piston 16 and the cylinder rod 15 is provided by an O-ring 21.

The piston 16 is mounted sealed in the chamber 17 formed inside the cylinder body 18, by means of segment seals 22.

The cylinder body 18 is mounted sliding and tight on the piston rod 15, by means of seals 23, 23 'and sliding rings 24 and 24 'and on the piston 16, via the seals segments 22, inside the chamber 17.

The cylinder body 18 consists of three parts 18a, 18b, 18c attached and fixed to each other the others by means of screws. Parts 18a and 18b of the cylinder body 18 delimit between them the chamber cylinder 17 in which the piston 16 is mounted.

The means 14 for actuating the jaws of the block of crimping 12 is fixed by screws at the outer end of part 18c of the cylinder body 18, that is to say opposite the fixed frame 11 and the chamber 17.

On the part 18b of the cylinder body 18 are fixed supply and purge nozzles 25a and 25b of the two parts 17a and 17b of the chamber 17 of the jack, of on either side of the piston 16.

We will now describe, with reference to the assembly of FIGS. 2A, 2B and 3, the crimping block 12 which comprises a jaw support 26 of tubular shape on which eight jaws such as 27a and 27b are mounted in positions located at 45 ° from each other around the axis of the tubular support 26. The jaws such as 27a and 27b are mounted movable in radial directions by compared to tubular support 26, thanks to slides respective 28a and 28b fixed on a support piece 29 fixed by means of a nut 29 'screwed onto the tubular support 26.

The jaws such as 27a and 27b have other share a notch which is engaged for guiding the corresponding jaw on a projecting part 27c of the support tubular 26. The jaws 27a and 27b are thus perfectly guided as they move in one direction radial, either in the direction of the axis of the support 26, or in the opposite direction.

Jaws 27a and 27b are likely to be move in the radial direction between a position loosened shown in Figure 2A and a position corresponding to the end of a crimping operation, shown in Figure 2B.

Jaws 27a and 27b have parts of crimping respectively 30a and 30b projecting towards inside, towards the axis of the support 26. The crimping of the outer ring as shown in Figure 1 is produced by the parallel bearing surfaces to the axis of the tubular support 26 directed inwards, crimping parts 30a and 30b.

Between the support 26 and the inner surface of the jaws such as 27a and 27b, at the bottom of the notch of guide, are arranged elastic return means 31 which are compressed, when the jaws such as 27a and 27b move inward to the crimp position shown in Figure 2B and which allow, made of their elasticity, the return of jaws 27a and 27b in their loose position as shown in the Figure 2A, after the crimping operation.

The jaws can also be recalled in loosened position by springs inserted between the bit.

At one end of the tubular support 26 is fixed between the jaws such as 27a and 27b, a cuff 32 for receiving an external ring to be crimped onto a flexible duct.

The support 26 has a threaded portion 33 and a rotation stop groove 34.

The support 26 is fixed to the frame 11, via of the nut sleeve 20 which has a part tapped at its end remote from the frame which can be screwed onto the threaded part 33 of the support 26 which is blocked in rotation around its axis through a key 35 or key engaged in a notch in the cylinder rod 15 and in the groove 34 of the support 26.

The cylinder rod 15, the nut sleeve 20 and the tubular support 26 are arranged coaxially, their common axis 36 also being the actuation axis of the hydraulic cylinder 13.

The jaws such as 27a and 27b have a respective external actuating surface 37a and 37b of frustoconical shape intended to cooperate with a surface internal frustoconical shape of the actuating means 14 annular integral with the end portion of the portion 18c of the cylinder body 18.

When the cylinder body 18 moves by compared to the cylinder rod 15 and the piston 16, the surface internal actuation of the annular actuation means 14 slides on the actuating surfaces such as 37a and 37b of the crimping jaws.

The sliding of the corresponding actuation surfaces on top of each other is facilitated by a lubrication device 38 for sending a lubricant on tapered actuation surfaces via a substantially directional channel 39 radial.

One or more force sensors 40 are arranged between support pieces 41 and 42 interposed between the support 29 of the jaws such as 27a and 27b and the cylinder rod 15.

Support pieces 41 and 42 lock by tightening the force sensor (s) via a threaded part 44 screwed onto the cylinder rod 15.

In addition, the threaded piece 44 makes it possible to obtain an axial preload of the force sensor 40, preload necessary for its operation.

A displacement sensor 43 is fixed on the upper part of the frame 11 and comprises a rod probe 43a in contact with a stop 45 fixed by a screw on the rear part of the cylinder body 18.

The sensors 40 and 43 make it possible to determine the forces and displacements involved during crimping and therefore very precisely control the operation crimping.

We will now describe, with reference to Figures 2A, 2B and 3, a crimping operation of a flexible pipe such as flexible pipe 1 between a ring outer 2 and an inner ring 4, as shown in the figure 1.

At first, an external ring such that the ring 2 is inserted inside the cuff receiving 32 whose inside diameter is substantially equal to the outer diameter of the ring external 2 in its insertion part of the flexible pipe 1.

Satisfactory positioning of the ring external 2 in the axial direction is ensured by setting in abutment of the inner end of the ring 2 on the anterior face of the support 26. The posterior end 2a of the outer ring 2 intended to receive the flexible hose 1 is then protruding at the front of the reception cuff 32, between the protruding parts of the crimping jaws such as 27a and 27b.

A flexible pipe such as 1 is brought and introduced, preferably automatically, inside of the rear part of the outer ring 2, by the front end of the crimping device 10, between the jaws such as 27a and 27b.

At the end of the introduction and implementation, the end of the flexible conduit 1 abuts on the lugs 3 of the outer ring 2 folded inwards.

An internal ring such as 4, possibly fitted with a seal 5, can be inserted inside of the bore of the nut sleeve 20, through the rear end of the crimping device 10 and pushed inside of the bore of the nut sleeve 20 and of the support 26, up to engage inside the end of the flexible pipe 1, as shown in Figure 1.

This operation of introduction and implementation place of the inner ring 4 is preferably made of automatically. It can be performed using a internal ring support, the support passing through the sleeve nut 20 and crimping block 12.

The fitting of the inner ring 4 can also be performed automatically outside the crimping head and the device described, inside of the flexible conduit 1, before its introduction inside of the rear part of the outer ring 2.

The device is then ready to carry out the crimping proper.

We supply the part 17a of the chamber 17 of the cylinder 13 located at the rear of the piston 16 in hydraulic fluid, so that the cylinder body 18 moves towards the rear between its position shown in Figure 2A and its position shown in Figure 2B.

During the displacement of the cylinder body 18, the hydraulic fluid contained in part 17b of the chamber 17 located at the front of the piston 16 is driven out by through the nozzle 25a.

The rearward movement of the cylinder body 18 and actuating means 14 of annular shape produces displacement in radial directions and inwards, i.e. towards axis 36 of the support 26, jaws 27a and 27b and in particular of their part crimping projecting inwards.

The crimping parts of the jaws 27a and 27b in inward projection come into contact with the posterior part of the outer ring 2 and exert compression forces on this posterior part, like represented by the arrows 7 in figure 1. The forces 7 radial direction compression deformation of the rear part 2a of the ring external 2 following corresponding successive sectors each has a crimping jaw, so that the surface inside of the rear part of the ring 2 sinks inside the flexible material of the duct 1 as represented by the dotted line 2'a on the figure 1.

The crimping of the flexible conduit 1 is ensured by compression of this conduit between the deformed outer ring and the inner ring. During crimping, the effort exerted by the jaws such as 27a and 27b on the ring external 2 and on the flexible conduit 1 can be measured and recorded by the force sensor 40. The movement of bit which is proportional to the displacement of the body of cylinder 18 can also be measured and recorded using the displacement sensor 43.

The crimping operation is thus perfectly controlled.

Before carrying out crimping operations in series on identical parts, a presetting of the crimping device by determining precisely the force and the displacement to put in works during the crimping operation to achieve a satisfactory fixing of the flexible conduit between the rings external and internal.

For this we carry out qualification tests such as tests for resistance to hot pressure and to cold of the connection obtained and measures of pull-out force flexible duct, on different connections made under a crimping effort and with a displacement that have been measured. We can thus define for a manufacturing given, the ideal crimp conditions.

Indeed, the efforts and displacements necessary for the implementation of a good crimp quality depend on different parameters related to elements of the fitting to be made. These parameters are in particular relating to the malleability of the outer ring metallic crimp which characterizes the ability to deform plastic of the outer ring during crimping, the structure of the flexible connector to be assembled, the thickness and variations in thickness of flexible conduits depending on the manufacturing technique of the conduits flexible, for example by extrusion and with characteristics of compression of the material constituting the flexible conduit.

When the crimping effort has been determined and displacement corresponding to ideal conditions for the manufacturing to be undertaken, we start manufacturing and we set the cylinder supply conditions for obtain the required crimping force. This setting can be done manually by monitoring the value displayed by the force sensor 40 or even so fully automatic using control means electronic cylinder connected to the force sensor 40.

The displacement sensor 43 makes it possible to determine the position of the cylinder body 18 at the end of the stroke crimping. The force sensor controls the stopping of the crimping, when the setpoint previously entered, is reached by reversing the feed direction of the hydraulic cylinder 13. The cylinder body 18 returns then forward and the jaws 27a and 27b are recalled in radial directions outward by the devices return bands 31.

The displacement sensor allows you to check whether the correlation force and displacement is correct compared to the results obtained during the development.

The assembled fitting is ejected, preferably from automatically, through the front of the device crimp 10.

The crimping device is ready for operation following crimping which can be performed from the as described above.

At the end of a production, to carry out the crimping of parts with characteristics different from those of the first production, we can perform new calibration and adjustment operations to obtain the efforts and displacements necessary to new manufacturing.

In case the diameters of the parts to be crimped are significantly different from one production to the next, it may be necessary to change the jaws of crimping carried by the support 26.

We then perform a complete block change crimping 12 formed by the support 26 and the jaws such as 27a and 27b.

This change can be made very quick by dismantling the actuating part 14 by simple unscrewing the connecting screws to the front part 18c of the cylinder body 18.

We then unscrew the nut sleeve 20 to release the crimping block 12. The crimping block 12 can then be extracted by simple pull in the axial direction 36, insofar as the key 35 is slidingly mounted in groove 34 ensuring retention in rotation of the support 26.

A replacement crimp block suitable for new part dimensions is then introduced in the device 10, so that its groove 34 comes to engage on the key 35 of the cylinder rod 15.

The nut sleeve 20 is replaced by screwing inside the bore of the cylinder rod 15 and on the threaded part of the support 26 of the crimping block of substitution.

The annular actuating means 14 is then replaced and fixed by screws on the end part front of the cylinder body 18.

The change of crimping tools is therefore extremely fast and requires no adjustment other than the usual calibration of crimping conditions for carry out a new manufacturing.

The device according to the invention therefore allows a very rapid adaptation to manufacturing concerning pieces of different diameters.

In addition, this device has a very large precision and allows crimping in perfectly defined conditions, to ensure characteristics wanted crimped parts.

The invention is not limited to the embodiment which has been described, but includes all of the embodiments which do not depart from the scope of the invention as claimed.

This is how we can consider using crimping blocks with a variable number of jaws whose forms may be significantly different from shapes described and shown.

Likewise, the structure of the cylinder and the part actuation may be significantly different from those that have been described.

Any type of sensor can be used to measure forces and displacements during crimping.

Finally, the invention applies not only to case of making connections for cooling circuit motor vehicle but still to realize any crimping of a metal ring on a cylindrical body, in any form of industry.

Claims (9)

1. Device for crimping a metallic ring (2) to a cylindrical body (1), of adjustable diameter, comprising a fixed frame (11), a crimping unit (12) itself comprising a jaw support (26), at least two jaws (27a, 27b) mounted to move on the support (26), towards each other in order to carry out the crimping and in the opposite direction for the release of the jaws (27a, 27b), the support (26) constituting with the jaws (27a, 27b) a removable crimping unit and a jack (13) for moving the jaws (27a, 27b) in order to carry out the crimping, through the intermediary of actuating means (14) comprising an actuating surface intended to come into engagement with a corresponding surface (37a, 37b) of the jaws (27a, 27b) for their movement in the radial direction of the support (26), characterized by the fact that the jack (13) for moving the jaws (27a, 27b) comprises a movable jack body (18) of tubular shape and a piston (16) integral with a jack rod (15) fixed to the frame (11), the jack body (18) defining a chamber (17) in which the piston (16) is engaged and mounted to slide on the piston (16) and on the jack rod (15), that the support (26) for the crimping jaws (27a, 27b) of general cylindrical shape is fixed to the frame (11) in a detachable manner, in axial alignment with the jack rod (15), that the means (14) for actuating the jaws (27a, 27b) are detachably fixed to one end of the jack body (18), for the movement of the jaws (27a, 27b) in the radial direction of the support (26), by movement of the jack body (18) in the axial direction and that in addition it comprises a force sensor (40) interposed, in a space of axial direction, between the crimping unit (12) and the jack rod (15) and a movement sensor (43) fixed to the fixed frame (11) comprising a feeler member (43a) cooperating with an abutment (45) integral with the jack body (18).
2. Crimping device according to Claim 1, characterized by the fact that the jack rod (15) is made in a tubular shape and that a nut sleeve (20) of tubular shape is mounted inside the jack rod (15) and comprises at one end, a tapped internal part (19a) for fixing a threaded part (33) of the support (26) for the jaws (27a, 27b), the internal bore of the nut sleeve (20) and the internal bore of the support (26) constructed in a tubular shape forming an extension (1) of the other.
3. Device according to Claim 2, characterized by the fact that the tubular support (26) for the jaws (27a, 27b) comprises a groove (34) in its outer surface, for the engagement of a key (35) for preventing rotation, engaged and fixed in the jack rod (15).
4. Device according to one of Claims 1 to 3, characterized by the fact that the means (14) for actuating the jaws (27a, 27b) are of annular shape and comprise an inner surface of substantially frustoconical shape, the jaws (27a, 27b) comprising corresponding actuating surfaces (37a, 37b) of frustoconical shape on their outer surface.
5. Device according to one of Claims 1 to 4, characterized by the fact that the jaws (27a, 27b) comprise a crimping part (30a, 30b) projecting inwards, i.e. towards the axis (36) of the support (26).
6. Device according to one of Claims 1 to 5, characterized by the fact that the support (26) for the jaws (27a, 27b) comprises a sleeve (32) for receiving a metal ring (2) at one of its ends disposed between the jaws (27a, 27b).
7. Device according to Claim 1, characterized by the fact that the force sensor (40) is interposed between the jack rod (15) and at least one support member (41, 42) locked by a threaded part (44) itself in abutment against the support (26) for the jaws (27a, 27b) ensuring the pre-stressing of the force sensor (40).
8. Device according to one of Claims 1 to 7, characterized by the fact that means (14) for actuating the jaws (27a, 27b) are fixed by screws to an end part (18c) of the jack body (18).
9. Use of a device according to one of Claims 1 to 7, for fixing one end of a flexible conduit (1) of an automobile vehicle engine between an inner ring (4) and an outer ring (2) which is deformed by crimping on the flexible pipe (1).

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