WO2018189441A1

WO2018189441A1 - Fluid tank having an external pipe held by a clip

Info

Publication number: WO2018189441A1
Application number: PCT/FR2018/050626
Authority: WO
Inventors: Sebastien Hureaux
Original assignee: Psa Automobiles Sa
Priority date: 2017-04-11
Filing date: 2018-03-15
Publication date: 2018-10-18
Also published as: MA50281A; FR3065026B1; FR3065026A1; EP3610140A1

Abstract

The invention relates to a fluid tank (1) equipped on its external periphery with at least one branch-off and with a flexible cable or pipe (3), a coupling (2a) of the said at least one branch-off to the tank (1) being situated near the pipe (3) held on the external periphery of the fluid tank (1) by a clip (4), secured to the tank (1) and gripping the pipe (3). A reel (5) surrounds a longitudinal portion of the pipe (3), being partially inserted and held in the clip (4) by clip-fastening means (5a) on the reel (5) collaborating with complementary clip-fastening means (4b) borne by the clip (4), a longitudinal part (5b) of the reel (5) extending externally beyond the clip (4) and being long enough to hold the pipe (3) at a distance of at least 20 mm away from the coupling (2a).

Description

FLUID RESERVOIR HAVING EXTERNAL PIPE

RETAINED BY A CLAMP

The invention relates to a fluid reservoir provided on its outer periphery of at least one tubing and a hose or flexible cable retained by a clamp secured to the outer periphery of the tank. A connection of said at least one tubing on the reservoir is close to the pipe held on the outer periphery of the fluid reservoir by a clamp, integral with the reservoir, enclosing the pipe. The fluid reservoir may be a consumable fluid reservoir. In particular, but without being limiting, the fluid reservoir may be a reducing agent reservoir for a selective catalytic reduction system also called RCS system, which name may be used in the following to designate it as well as for designate its constituent parts as RCS reservoir for the reducing agent reservoir. However, in the automotive field, the tank according to the present invention may be a fuel tank or any other type of tank containing a fluid.

Thus, in what follows, it will be taken the example of a RCS tank to describe the present invention. This is not limiting and the present invention may relate to any fluid reservoir provided with a hose or flexible cable and a tubing, the hose to interfere with the tubing by bending, this even in a field other than the field automobile.

Such a reservoir may have one or more conduits, for example inlet or outlet conduits of the fluid that the reservoir contains. It can be a filler neck connected to the tank, a tank fluid outlet pipe or a degassing pipe. These ducts are generally rigid and not subject to bending.

For example, in the non-limiting case of a reducing agent tank RCS, it has been developed filling channels which will be housed by a small hatch located on the side of the vehicle, as well as RCS tanks located in the lower part of the underbody of the vehicle. As pollution control standards become more stringent, the RCS tank is condemned to be filled more and more frequently. By cons, other pipes or cables connected to the tank may be flexible. This is the case of an electrical bundle wrapped in a flexible sheath that can bend and interfere with one or more tubings present on the outer periphery of the tank on the same side of the tank. Still taking as an example a RCS tank, most diesel vehicles currently manufactured will include at least one RCS tank. The tubing or pipes, and at least the filler neck, can be monoblock with the reservoir. Alternatively, they can be manufactured independently of the tank and have to be returned to the tank later, by an operation known as sleeving.

The tank thus equipped is then mounted on the vehicle, in the terminal plant, by a so-called styling operation, consisting in depositing the tank and its tubings on a plate, also called sled, arranged under the vehicle basement, then to mount the assembly on the vehicle. During the sled preparation operation, the RCS tubing is mounted snapped on the RCS tank. Then, it is the turn of the RCS pipe to be snapped onto the tank. On a rear panel of the tank, a clamp, preferably C, must fix the electrical harness of the RCS heating pipe relative to the tank. The surrounding area is very compact, having to renew the state of the RCS tubing and not to degrade the capacity of the tank for its autonomy, it was not possible to move the location of certain electrical connectors.

[001 1] Referring to Figures 1 and 2, these figures show an RCS tank front 1 carrying an electrical connector 14 of heating pipe bundle, the beam 3 having been removed in Figure 1 but being visible in Figure 2 The tank front RCS 1 carries a degassing tubing RCS 2, only visible in Figure 2, connecting to the RCS tank front 1 by a connector 2a, preferably a quick connect coupling 2a. The tank front 1 also comprises a RCS 13 filling pipe, visible only in FIG. 2, with its connection 13a to the tank front RCS 1.

This RCS 2 filling pipe is disposed relatively spaced from the beam 3 and the beam 3 does not present any risk of interference with the tubing of RCS 13 filling and in particular with its connection 13a. As can be seen in FIG. 2, the electrical harness 3 is held locally in a clamp 4 secured to the RCS tank front 1.

For ergonomic reasons teminale factory, two electrical connectors 14, 14a which are present on the front of the tank RCS 1 must be left accessible in the upper part to be able to connect the power harness of a passenger compartment of the vehicle and the electrical wiring harness 3 RCS RCS 1.

As can be seen in FIG. 2, in this case for the electric harness 3 of the heating pipe which goes down slightly below the level of the upper face of the tank RCS 1, the electrical harness passes close to the coupling 2a. the degassing tubing 2 RCS, this proximity may vary from 0 to 10mm. It is therefore known to ensure the path of the electrical harness with a flexible mechanical protection sheath by a clamp 4 C placed at the joint plane. In this configuration, there is nevertheless a very significant risk of collapse by gravity of the electrical harness 3 of the heating pipe, this bundle 3 being relatively flexible and subject to bending, on the connection 2a of the degassing pipe 2 RCS tank. In FIG. 2, the zone encircled and referenced Z is the most probable zone of interference between the electrical harness 3 and the connection 2a of the degassing pipe 2 of the RCS reservoir.

In addition, the mechanical tension exerted on the electrical harness 3 does not control its course and therefore its sagging in the duration. This may result in contact between the electrical harness 3 and the degassing pipe 2 of the RCS tank instead of having a spacing of 1 to 10 mm between these two elements. In the case of a contact between these two elements, the sheath of the electrical harness 3 of the heating pipe of the RCS tank can abrade by abrasion the connection 2a of the degassing pipe 2, preferably a quick-connect coupling, This may cause a risk of SCR tank reducing agent leakage. More or less abrasive contact on such a quick-connect coupling is to be avoided. FR-A-3 034 052 discloses a set of fluid reservoirs, a first chute is attached to a second chute in the filling area by fixing means comprising a first portion attached to the first chute and integrally connected to a second part in the form of clamps gripping the second chute on half of its periphery. The clip-shaped portion has a C shape and snaps into force around the periphery of the second chute.

This document therefore reproduces the state of the art relating to the use of a clamp but it has been found that the use taken in isolation of a clamp is not sufficient to prohibit any bending of the electrical harness. and its interference with the degassing tubing.

Therefore, the problem underlying the present invention is, for a fluid reservoir comprising at least one tubular connected to the outer periphery of the tank and a hose or flexible cable that may interfere with said at least one tubing by bending, to avoid such interference.

To achieve this objective, there is provided according to the invention a fluid reservoir provided on its outer periphery of at least one tubing and a hose or flexible cable, a connection of said at least one tubing on the reservoir located near the pipe held on the outer periphery of the fluid reservoir by a clamp, integral with the reservoir and locally enclosing the pipe, characterized in that a coil surrounds a longitudinal portion of the pipe being partially inserted and retained in the clamp by snap-fastening means carried by the winding cooperating with complementary snap-fastening means carried by the clamp, a longitudinal part of the spool protruding outwardly from the clamp being of sufficient length to hold the pipe at a distance from the equal connection at least 20 mm, in particular at least 30 mm. This prevents any contact between the pipe and the fitting.

The technical effect is to obtain a better hold against the bending or collapse of the hose or flexible cable that could interfere with the connection of the tubing. The reel serves as a holding sleeve for the hose or flexible cable while being snapped with the clamp, hence maintaining the winding optimal and easy to achieve by pressing the reel in the clamp.

The bobbin is a simple but effective way to combat bending or collapse of the hose or flexible cable, this in addition to maintaining the hose or flexible cable by the clamp. The reel, independent of the tank before attachment with the clamp, is an insert and its presence requires no specific adaptation around the tank. It is nevertheless possible to raise the position of the clamp on a front of the tank carrying it but this is not mandatory. Advantageously, the bobbin is of cylindrical shape having, on its outer periphery to a longitudinal end portion, a radial groove received in the clamp, the groove forming the latching means of the bobbin. The snapping of the winder is done by pressure exerted by an assembler on the winding in the direction of the clamp, which is a solidarization operation easy to implement.

Advantageously, the clamp comprises two arms defining between them an internal space receiving the bobbin, the two arms leaving between their free ends an opening, the free ends of the arms being bent towards the internal space, these free ends of the arms realizing the complementary snap-fastening means by fitting into the throat of the bobbin. This is the restoring force due to the elasticity of the arm resembling the free ends of the arms towards one another which closes the free ends of the arms in the groove of the winder.

This snapping is done automatically when the bobbin is pressed into the inner space of the clamp, the free ends of the arm first apart from each other and then being recalled in close positions one on the other when the groove of the reel is opposite the circumference of the internal space of the clamp.

Advantageously, the clamp has, on the one hand, a shape of C, the inner space having a substantially circular section and, on the other hand, a connecting member solidarisant the C shape with the outer periphery of the tank , the connecting element being in the form of a square whose one branch bears against the outer periphery of the tank.

The connecting element, advantageously in one piece with the arms, provides the connection between the clamp and the tank and its square shape with the support of a branch of the bracket on the outer periphery of the tank makes this connection stronger, the winding and the pipe or cable, although a light weight, overhanging relative to the outer periphery of the tank being kept at a distance from this periphery.

Advantageously, the bobbin is made of high density polyethylene or polyamide 6.6. These materials are sufficiently rigid to be non-flexible under the weight of the pipe. The spool thus forms a non-deformable sleeve under the pressure of the pipe or cable, which prevents the pipe or cable from bending or sagging. The snap is made reliable by the use of a rigid plastic bobbin. The risk of Disengagement is removed with a rigid interface between plastic bobbin. The clamp can be obtained by injection on the tank.

Due to the rigid nature of the plastic material of the winder, it is obtained a better feeling in the assembly by a snap more snug in the clamp carried by the tank and durable in the duration, this in contrast to the hose or flexible cable, by a protective sheath of an electrical harness, which can be brought out of the clamp in time and by vibration.

Advantageously, the reel is in two parts hinged together by a hinge extending in a length of the reel, the hinge allowing the reel to take an open position in which the two hinged parts are open by being arranged l next to one another and a closed position in which the two hinged parts are folded against each other to form a closed assembly, one of the two hinged parts having at least one protruding lug and penetrating into a groove carried by the other portion in the closed position of the bobbin, a longitudinal median passage being formed between the two portions for receiving the pipe. This makes it easy to return the hose or flexible cable into the winder, the reel then being in the open position. Then, the reel is put in the closed position by completely surrounding the pipe or cable.

Advantageously, the pipe is a power supply harness of the reservoir surrounded by a flexible sheath and the connection of said at least one pipe is a quick-connect coupling. A power harness is a generally flexible element and requires the use of the spool to be held in position and not to bend.

Advantageously, the clamp is disposed near an upper rounded edge of the tank, the pipe forming a bend at one end of the outer coil to the clamp. The elbow can then bear against the upper face of the reel. It is advantageous to position the reel towards the highest portion of the hose or flexible cable so that it can combat any deflection of the hose or flexible cable. Positioning the winder halfway up the hose or flexible cable could not guarantee such protection against bending. Advantageously, the reservoir is a reducing agent reservoir for a selective catalytic reduction system in a motor vehicle, the pipe being a power supply beam for heating a reducing agent pipe and said at least one a tubing being a degassing tubing of the agent reservoir reducer. It is also possible that the tank is a fuel tank or other liquid used in the motor vehicle.

The invention also relates to a method of mounting such a pipe or such a flexible cable held on an outer periphery of a fluid reservoir, the method having the following steps:

- mounting a winding around a length portion of the pipe,

- introduction of the winder, enclosing the portion of the pipe in its interior, in a clip secured to the outer periphery of the tank, a longitudinal portion of the bobbin protruding from the clamp,

- Snap the bobbin into the clamp.

According to the invention, it is obtained firstly a technical gain due to the securing of the distance between tubing and hose or flexible cable with an increase in the proximity distance equal to at least 30mm. Another technical gain relates to the assembly and the controlled installation of the reel which is moreover now the competence of the supplier of the hose or flexible cable, thus a discharge of the work of an operator in the assembly workshop of the tank. Finally, the snap-in represents a simple fastening of implementation obtained by a simple pressure of the bobbin in the internal space of the clamp.

Another gain obtained is the reliability against leakage of the connection of the tubing that is no longer likely to be in contact with the hose or flexible cable. It is also obtained an improvement of the functional quality gain with a reduction of the risk of degradation and leakage of fluid contained in the reservoir, for example a reducing agent, on elements located near the connection of the tubing.

Finally, it is afforded an economic gain for a motor vehicle, because during the passage in the concession of the vehicle, it will no longer be necessary to check whether the pipe or cable is always latched on the clamp. This control operation can be deleted and also simplifies the work of the operator in after-sales.

Other features, objects and advantages of the present invention will appear on reading the detailed description which follows and with reference to the accompanying drawings given by way of non-limiting examples and in which:

FIGS. 1 and 2 are diagrammatic representations in perspective of a RCS tank facade according to the state of the art with an electrical harness and a degassing nozzle located close to one another, FIGS. 3 to 6 are diagrammatic representations of perspective views at different angles of a RCS tank facade according to the present invention, an electric harness carrying a coil being partially introduced into the holding clip of the electric harness,

FIGS. 7 and 8 are schematic representations of perspective views respectively in the closed position and in the open position of an embodiment of a coil used around an electrical harness in a RCS tank facade according to FIG. present invention.

It is to be borne in mind that the figures are given by way of examples and are not limiting of the invention. They constitute schematic representations of principle intended to facilitate the understanding of the invention and are not necessarily at the scale of practical applications. In particular, the dimensions of the various elements illustrated are not representative of reality.

In what follows, reference is made to all the figures taken in combination. When reference is made to one or more specific figures, these figures are to be taken in combination with the other figures for the recognition of the designated reference numerals.

In what follows, we understand the terms "upper", "lower", and other references to spatial positioning with reference to components positioned in their operating position and normal use, especially when the reservoir is disposed vertically, advantageously a RCS tank in a motor vehicle lying on a horizontal plane.

[0043] FIGS. 1 and 2 have already been described in the introductory part of the present application. Referring to Figures 3 to 8, the present invention relates to a fluid reservoir 1 provided on its outer periphery of at least one tubing 2 and a hose 3 or flexible cable. The fact that this pipe or cable is illustrated in these figures as an electric harness is not limiting in the context of the present invention. In general, the tubing and the hose or flexible cable extend on the same face or front of the reservoir 1 of fluid.

This hose 3 or flexible cable is flexible enough to be able to flex and change from its original position to a lower curved position vertically. Cable means in particular electrical cable surrounded by a sheath that can be abrasive on said at least one pipe 2 in case of collapse of the sheath, but this is not limiting.

This reservoir 1 of fluid is in Figures 3 to 6 in the form of a reservoir RCS, which is not limiting but merely illustrative. There could then be interference between the pipe 3 or the flexible cable and a connection 2a of the at least one pipe 2 on the tank 1 located near the pipe 3.

As illustrated in FIGS. 1 and 2 and in FIG. 3, the periphery of the tank 1 according to the present invention can also receive a RCS 13 filling pipe provided with its connection 13a and carry a second electrical connector 14a, advantageously for a power supply to the passenger compartment of the vehicle. These characteristics are however not essential for the implementation of the present invention.

To prevent any displacement of the pipe 3 or flexible cable relative to the tank 1, the pipe 3 or cable is held on the outer periphery of the fluid reservoir 1 by a clamp 4, secured to the tank 1 and enclosing the pipe 3 or cable. This is known from the state of the art but has proved insufficient.

To improve the strength of the pipe 3 or cable, the present invention provides that a winding 5 surrounds a longitudinal portion of the pipe 3. The winding 5 is partially inserted and retained in the clamp 4 by latching means 5a carried by the bobbin 5 cooperating with complementary latching means 4b carried by the clamp 4.

However, a longitudinal portion 5b of the winder 5 protrudes externally of the clamp 4 by being of sufficient length to maintain the pipe 3 at a distance from the connection 2a equal to at least 30 mm thus preventing any contact between the pipe 3 and the connection 2a. This longitudinal part 5b of the winding 5 protruding from the clamp 4 exerts a resistance of the pipe 3 or cable which it encloses a longitudinal portion. The pipe 3 or cable is less likely to bend or sag with this additional support, equivalent to a corset or local stiffening sleeve.

The bobbin 5 may be of cylindrical shape having, on its outer periphery towards a longitudinal end portion, a radial groove 5a received in the clamp 4, the groove 5a forming the latching means 5a of the bobbin 5. The bobbin 5 can be pierced right through its longitudinal median axis and around this axis longitudinal median of a median passage for the reception of a portion of pipe 3 or cable inside the coil 5.

The longitudinal portion 5b of the coil 5 protruding externally of the clamp 4 has a length equivalent to two to three times the width of the groove 5a, or more. This is not limiting.

In one embodiment of the clamp 4, the clamp 4 may comprise two arms 4a terminated by free ends 4b defining between them an internal space receiving the bobbin 5. The two arms 4a can leave between their free ends 4b a opening. The arms 4a may advantageously be elastic while being brought against each other while respecting between the free ends 4b a predetermined opening. The free ends 4b of the arms 4a can be bent towards the internal space of the clamp 4, these free ends 4b of the arms 4a providing the complementary latching means 4b by penetrating into the groove 5a to effect the latching. This can be seen in particular in Figure 4. The clamp 4 may have, on the one hand, a shape of C, the inner space having a substantially circular section. On the other hand, the clamp 4 may have a connecting element 4c solidifying the C-shape with the outer periphery of the tank 1. The connecting element 4c, which can be in one piece with the arms 4a, can be in the form of a bracket whose branch bears against the outer periphery of the tank 1.

The bobbin 5 may be high density polyethylene or polyamide 6.6. These materials are sufficiently rigid, therefore stiffer than the hose or cable, to be non-flexible under the weight of the hose 3 or cable. The position in position of the pipe 3 or the cable against bending or sagging is reinforced. The bobbin 5, in two longitudinal parts or not, may be transparent plastic material.

As shown in Figures 7 and 8, the reel 5 may be in two parts 6a, 6b hinged together by a hinge 7 extending over a section of the length of the reel 5, at least partially with respect to the length 5. The hinge 7 can extend over less than half of the total length of the winder 5, this on a section of the winding 5 not bearing the groove 5a.

The hinge 7 may allow the bobbin 5 to take an open position, visible in Figure 8, wherein the two articulated portions 6a, 6b are open by being arranged next to each other and a closed position, as shown in Figure 7 in which the two parts 6a, 6b hinged are folded against each other to form a closed assembly.

Particularly visible in Figure 7, one 6a of the two parts 6a, 6b hinged together may have at least one lug 8 projecting and can penetrate into a groove 9 carried by the other part 6b in the position of closing the spool 5, the groove 9 serving as a housing for said at least one lug 8. In the closed position, a median longitudinal passage 10 is delimited by the inside of the two parts 6a, 6b hinged together to receive the pipe 3 or cable flexible. The lug 8 can snap into the groove 9.

In a preferred application, the pipe 3 or the cable may be a power supply beam of the tank 1 surrounded by a flexible sheath and the connection 2a of said at least one pipe 2 is a connection 2a with quick connection. The flexible sheath may nevertheless be abrasive with respect to the quick-connect fitting 2a and cause leakage of the liquid contained in the tank 1.

The clamp 4 may be disposed near a rounded upper edge 1 1 of the tank 1, the pipe 3 forming a bend 12 at one end of the outer coil 5 to the clamp 4. It is possible or even advantageous to change the position of the clamp 4 already present on a tank 1 of the state of the art without reel 5 and enhance it within the scope of the present invention. The clamp 4 is then close to the rounded edge 1 1 of the tank 1 being secured to a substantially flat surface of the periphery of the tank 1 for better fastening. The upper end of the longitudinal portion 5b of the winder is then substantially at the level of the electric beam 14, as can be seen in particular in FIG. 5. In the preferred application of the present invention, the tank 1 can be a reducing agent tank 1 for a selective catalytic reduction system in a motor vehicle. In this case, the pipe 3 or cable may be a power supply bundle for heating a reducing agent pipe and said at least one pipe 2 may be a degassing pipe 2 of the reducing agent tank 1, these two elements being close to each other on the same facade of the tank 1.

The invention also relates to a method of mounting such a pipe 3 or such a flexible cable held on an outer periphery of a fluid reservoir 1. The process comprises the step of mounting a reel 5 around a length portion of the pipe 3 followed by a step of introducing the reel 5, enclosing the portion of the pipe 3 in its interior, in a clamp 4 secured to the periphery outside of the tank 1, a longitudinal part 5b of the spool 5 protruding from the clamp 4. The method finally comprises a step of snapping the spool 5 into the clamp 4.

The bobbin can be mounted on the hose or flexible cable at the supplier, which will secure the voltage and travel of the pipe or flexible cable, preferably a RCS electrical pipe.

The invention is not limited to the described and illustrated embodiments which have been given only as examples.

Claims

Reservoir (1) of fluid provided on its outer periphery with at least one tubing (2) and a hose (3) or flexible cable, a connection (2a) of said at least one tubing

(2) on the reservoir (1) located near the pipe (3) held on the outer periphery of the reservoir (1) of fluid by a clamp (4), integral with the reservoir (1) and locally clamping the pipe (3). ), characterized in that a reel (5) surrounds a longitudinal portion of the pipe (3) by being partially inserted and retained in the clamp (4) by latching means (5a) carried by the cooperating bobbin (5) with complementary locking means (4b) carried by the clamp (4), a longitudinal part (5b) of the winder (5) protruding outwardly from the clamp (4) being of sufficient length to hold the pipe

(3) at a distance from the connector (2a) equal to at least 20 mm, in particular at least 30 mm.

Tank (1) according to claim 1, wherein the bobbin (5) is of cylindrical shape having, on its outer periphery towards a longitudinal end portion, a radial groove (5a) received in the clamp (4), the groove (5a) embodying the latching means (5a) of the spool (5).

Tank (1) according to claim 2, wherein the clamp (4) comprises two arms (4a) delimiting between them an internal space receiving the bobbin (5), the two arms (4a) leaving between their free ends (4b) a opening, the free ends (4b) of the arms (4a) being curved towards the internal space, these free ends (4b) of the arms (4a) providing the complementary latching means (4b) by fitting into the groove ( 5a) of the bobbin (5).

Tank (1) according to claim 3, wherein the clamp

(4) has, on the one hand, a shape of C, the inner space having a substantially circular section and, on the other hand, a connecting element (4c) solidarizing the C shape with the outer periphery of the tank ( 1), the connecting element (4c) being in the form of a bracket whose branch bears against the outer periphery of the tank (1) -

Tank (1) according to any one of the preceding claims, wherein the bobbin

(5) is made of high density polyethylene or polyamide 6.6.

6. Tank (1) according to any one of the preceding claims, wherein the bobbin (5) is in two parts (6a, 6b) hinged together by a hinge (7) extending in a length of the bobbin (5). ), the hinge (7) allowing the bobbin (5) to take an open position in which the two articulated portions (6a, 6b) are open by being arranged next to each other and a closed position wherein the two articulated portions (6a, 6b) are folded against each other to form a closed assembly, one (6a) of the two parts (6a, 6b) hinged together having at least one lug (8 protruding into a groove (9) carried by the other part (6b) in the closed position of the spool (5), a longitudinal median passage (10) being formed between the two parts (6a, 6b) for receive the hose (3).

7. Tank (1) according to any one of the preceding claims, wherein the pipe (3) is an electrical power supply of the reservoir (1) surrounded by a flexible sheath and the connection (2a) of said at least a tubing (2) is a quick-connect fitting (2a).

8. Tank (1) according to any one of the preceding claims, wherein the clamp (4) is disposed near a rounded edge (1 1) of the upper tank (1), the pipe (3) forming a bend (12) at one end of the bobbin (5) external to the clamp (4).

9. Tank (1) according to any one of the preceding claims, which is a reservoir (1) of reducing agent for a selective catalytic reduction system in a motor vehicle, the pipe (3) being a beam of electric power supply for heating a reducing agent pipe and said at least one pipe being a degassing pipe (2) of the reducing agent tank (1).

10. A method of mounting a pipe (3) or a flexible cable held on an outer periphery of a fluid reservoir (1) according to any one of the preceding claims, the method having the following steps:

- mounting a reel (5) around a length portion of the pipe (3),

- Introducing the winding (5), enclosing the portion of the pipe (3) in its interior, in a clamp (4) secured to the outer periphery of the tank (1), a longitudinal portion (5b) of the winding (5) protruding from the clip (4),

- snap the bobbin (5) in the clamp (4).