FR3103029A1 - Electric fluid heating device, in particular intended for a vehicle, and cover for a housing of such a device - Google Patents

Abstract

The present invention relates to an electrical fluid heating device for a motor vehicle, comprising a housing for circulating the fluid, at least one electric heating element, and a cover closing said housing and carrying said one or more electric heating elements. The electric heater is characterized in that the cover is press-fitted to the housing so that the electric heating element (s) extend into the housing. Figure for the abstract: Figure 4.

Description

Electric fluid heating device, in particular intended for a vehicle, and cover for a housing of such a device

The invention relates to a fluid heating device, in particular intended for a vehicle, more particularly for a ventilation, heating and/or air conditioning installation for the passenger compartment of the vehicle and/or the thermo-regulation of a battery. This may include an electric or hybrid vehicle that can be autonomous. The invention also relates to a cover for a housing of such a device.

It is known to ensure the heating of the air intended for the heat treatment of the passenger compartment of a vehicle by heat exchange between a flow of air and a heat transfer liquid, by means of a heat exchanger. In the case of hybrid or electric vehicles, electric heating devices are known which form a source of heat and in which an electric current is circulated to raise the temperature of at least one electric heating element placed in contact with the heat transfer liquid. There is then an exchange of calories between the heating element and the coolant which in turn heats up before heating the passenger compartment thanks to the exchanger.

In particular, a heating device for a hybrid or electric vehicle is known comprising a housing in which the heat exchange takes place between the heating element(s) and the heat transfer liquid. Said box delimits a chamber which is accessible through an opening closed off by means of a lid. In particular, the opening has a side wall as well as a shoulder. The cover comprises a base carrying the heating element or elements, as well as a periphery which extends from said base to a free edge.

The base and the periphery of the cover are respectively in contact with the shoulder and the side wall of the opening of the case. Screws connecting the base of the cover and the shoulder of the opening of the case ensure that said cover is held in position on the case. It is also necessary to ensure a tightness of the case-cover connection. For this, a first option is to use a removable seal placed in a peripheral groove between the box and the cover.

Such a heating device has several drawbacks. First of all, the machining of the groove intended to receive the removable seal, whether it is carried out at the level of the housing or at the level of the cover, represents a cost which necessarily affects the final cost price of the heating device. . Then, for the assembly of this device, the operator first places the seal in its groove, then fits the cover in the box, before fixing the assembly by means of screws. This assembly process presents a complexity related to the relatively large number of components present and the number of steps to be performed. The complexity of the process also lies in the fact that the operator inserts the lid into the opening of the box without being able to check the presence of the seal in its groove. In addition, it often happens that the seal is deformed inappropriately during assembly, thus reducing its performance.

The object of the present invention is to propose a heating device which at least partially overcomes the drawbacks listed above.

To this end, the subject of the invention is an electric fluid heating device, in particular for a motor vehicle, comprising a fluid circulation box, at least one electric heating element, and a cover closing said box and carrying said electric heating elements. According to the invention, the cover is mounted on the casing by force-fitting so that the electric heating element(s) extend into the casing.

The press-fitting of the cover in the box allows assembly of these two parts without the need for an intermediate fixing element. Thus, contrary to the prior art where fixing screws are used between the cover and the housing, the force fitting in the present invention offers the advantage of limiting the number of components as well as the weight of the heating device. . In addition, the press-fitting makes it possible to obtain a seal at the interface between the cover and the box, avoiding the need to use a removable gasket.

The press-fitting leads the cover and the casing respectively into a state of compression and tension, with the setting of said cover and of said casing at a common diameter Df which is between the longest external diameter of said cover before fitting, denoted Dc, and the longest internal diameter of said casing before fitting, denoted Db.

The invention may also include any of the following features, taken individually or in any technically possible combination:

- the cover comprises a base as well as a periphery;

- the base of the cover comprises at its center a counter-shape forming a depression with the periphery of said cover;

- the counter-shape of the cover is configured to receive the electrical heating element(s);

- the housing comprises an opening comprising a side wall and a shoulder;

- the base and the periphery of the cover are in contact respectively with the shoulder and the side wall of the opening of the case;

- the electrical heating element comprises a resistor and at least one electrical connection terminal;

- the resistance of the electrical element extends into the housing;

- the electrical connection terminal(s) extend through the cover on either side thereof;

- the cover and the box form an interface provided at least partially with a sealing element;

- the sealing element at the interface between the cover and the case includes a film of polymeric material;

- the polymer material of the sealing element includes an adhesive;

- the housing defines a fluid circulation chamber;

- the housing comprises at least two fluid connection members intended to supply its chamber;

- the electrical heating element(s) extend into the chamber formed by the casing.

The invention also relates to a cover for a casing of the heating device as described above, said cover comprising a base, a periphery extending from said base, and at least one electric heating element, said base carrying the said element(s). electric heaters. According to the invention, the cover is intended to pass from a first configuration, before assembly, in which said periphery has a flared shape, to a second configuration, after force fitting, in which said periphery has a straightened shape.

The invention will be better understood and other details, characteristics and advantages of the invention will appear on reading the following description given by way of non-limiting example and with reference to the appended drawings, in which:

- FIG. 1 is a view in longitudinal section of an example of a heating device according to the invention comprising a casing, heating elements and a cover force-fitted in said casing;

- Figure 2 is a longitudinal sectional view illustrating a longitudinal end of the housing (Figure 2a) and the cover (Figure 2b) of the device of Figure 1;

- Figure 3 is an enlarged view of Figure 1 illustrating the cover mounted in the housing;

- FIG. 4 represents the steps for assembling the lid in the casing according to a sectional view illustrating: the lid separated from the casing (FIG. 4a); the cover positioned on an edge of an opening of the housing (figure 4b), a detail of figure 4b (figure 4c); the cover fitted into the housing (Figure 4d).

First of all, it should be noted that in all of the figures, elements that are similar and/or fulfill the same function are indicated by the same reference.

By convention, throughout this document, the qualifier "longitudinal" applies to the direction in which the largest dimension of the electric heating device extends, the qualifier "transverse" applies to a direction substantially perpendicular to the longitudinal direction, and the qualifier "vertical" designates the direction perpendicular to both the longitudinal direction and the transverse direction.

Furthermore, with reference to the orientations and directions defined previously, the longitudinal direction will be represented by the Ox axis, the transverse direction will be represented by the Oy axis, and the vertical direction will be represented by the Oz axis. These different axes together define an orthonormal reference Oxyz shown in the figures. In this frame, the qualifiers "high" or "upper" will be represented by the positive direction of the axis Oz, the qualifiers "low" or "lower" being represented by the negative direction of this same axis Oz.

As illustrated in Figure 1, the invention relates to a heating device 1. Said device is used to heat a fluid, in particular a heat transfer liquid. Said device comprises a casing 2 for circulation of the fluid, at least one heating element 4, here three, and a cover 6 closing said casing and carrying the said heating element(s).

In particular, the casing 2 defines a fluid circulation chamber 21 which is arranged to receive the heating element(s) 4 so that the fluid circulating in said casing is brought into contact with said electric heating elements.

To ensure this circulation of the fluid in the chamber 21, the housing 2 comprises at least one first inlet pipe 22 and at least one second outlet pipe 23 in communication with said chamber 21. The pipes 22, 23 are arranged in a same side of housing 2, here at the level of a bottom 10 of chamber 21. Said outlet pipe 23 opens directly into chamber 21. Said inlet pipe 22 opens into chamber 21, via one end of the latter opposite the bottom 10, via a channel 25 running longitudinally along said chamber 21 and opening into the latter through a slot 26.

The housing 2 is formed, for example, by casting aluminum and/or aluminum alloy.

As shown in Figure 2a, the housing 2 has an opening 24 which opens into the chamber 21 opposite the bottom 10, said opening 24 comprises a beveled edge 24a and a shoulder 24b between which extends a side wall 24c. Said shoulder 24b and said side wall 24c forming a recess 24d.

Referring to Figures 2b and 3, the cover 6 comprises a base 61 and a periphery 62 which form at their junction an elbow 63. In particular, the base 61 is provided with openings 61a for mounting the heating element(s) 4. periphery 62 of cover 6 has an inner wall 62a, an outer wall 62b opposite said inner wall and a free edge 62c. It should be noted that the cover 6 illustrated in FIG. 1 is simplified compared to that illustrated in the other figures.

Said cover 6 is formed, for example, by stamping aluminum and/or aluminum alloy.

In relation to FIG. 3, each heating element 4 comprises a shielded resistor 41 as well as at least one connection terminal 42 intended to connect said resistor to a current supply source. In addition, each heating element 4 is mounted in the cover 6 by inserting its terminals 42 into respective openings 61 of said cover. The connection between said terminals 42 and said openings 61 is made in a sealed manner. It should be noted that said heating elements 4 are not illustrated in Figures 2 and 4.

According to the invention, the cover 6 is mounted in the opening 24 of the housing by force fitting. In particular, the base 61 of the cover 6 bears against the shoulder 24b of the opening 24 of the chamber 21. The outer wall 62b of the cover 6 is in contact at least partially with the side wall 24c of the opening 24 of the chamber 21, and extends outward from said chamber. The contact between the outer wall 62b of the cover 6 and the side wall 24c of the opening 24 induces a straightening of the periphery 62 of said cover and a deformation of the material of the casing 2.

In this configuration, the electrical heating elements 4 mounted on the cover 6 are such that the respective resistors 41 extend into the chamber 21 of the box 2, while the respective terminals 42 extend through said cover and open out at the exterior of said chamber.

Advantageously, the base 61 of the cover 6 has in its center a counter-form 64 which deviates from the rest of said base in a direction substantially parallel to the longitudinal axis of the box 2. The counter-form 64 comprises a ramp 64a which extends, here in a cone, from a peripheral part 61b of the base 61, as well as a plate 64a which is arranged at the end of said ramp in a concave manner with respect to the chamber 21.

In this embodiment, the mounting openings 61a of the heating element(s) 4 are formed at the level of the plate 64b.

Furthermore, the ramp 64a is connected to the plate 64b and to the peripheral part 61b of the base 61 respectively by elbows 64c. Furthermore, said ramp 64a has a cone angle αr of between 5° and 175°, and preferably substantially equal to 40°. Finally, said ramp 64a forms with the peripheral part 61b of the base 61 and the periphery 62 an annular depression 65.

Thus, with two distinct zones, namely the counter-form 64 and the depression 65, the cover 6 has a structure capable of withstanding the fitting forces and of preserving the integrity of the connection between the cover 6 and the heating elements 4. Indeed, the elbows 64c formed respectively at the junction between the ramp 64a and the plate 64b and at the junction between the ramp 64a and the peripheral part 61b of the base 61 make it possible to absorb the fitting forces occurring between the periphery 62 of the cover 6 and the casing 2. In addition, said depression 65 defines a zone for applying a fitting tool.

Referring to Figure 2b, the free edge 62c of the periphery 62 is positioned in a plane located above the plane containing the plate 64b of the counter-form 64. However, the edge 62c can be positioned in a plane located at -beneath the plane containing the plate 64b without this embodiment departing from the spirit of the present invention.

Referring to Figure 3, the depression 65 comprises a face 65a formed by the peripheral part 61b of the base 61, an outer wall 65b formed by the periphery 62 of the cover 6 and an inner wall 65c formed by the ramp 64a. The depression 65 has a width Ld which increases between its face 65a and the plate 64b, in relation to the taper of the ramp 64a.

Advantageously, a sealing element 8 is arranged between the cover 6 and the box 2, and in particular at the interface between the base 61 and the shoulder 24b, or at the interface between the periphery 62 and the side wall 24c of the opening 24 of the chamber 21. The sealing element 8 comprises a film of polymeric material which fills in any surface defects present on the respective facing faces of the side wall 24c and of the periphery 62 of the lid.

In particular, the polymer material forming the sealing element 8 advantageously comprises an adhesive which reinforces the resistance of the lid 6 to disengagement.

Referring to Figure 4, the periphery 62 of the cover 6 extends from the base 61 to the free edge 62c of said cover between a first configuration in which said periphery has a flared shape corresponding to the position of said separate cover of said housing (figure 4a) and a second configuration in which said periphery has a straightened shape corresponding to the position of said fitted cover in said housing (FIG. 4d).

Before fitting, the free edge 62c and the base 61 of the cover 6 respectively have an outer diameter Dc1 and an outer diameter Dc2 such that Dc1≥Db and Dc2≤Db, with Db the diameter of the opening 24 of the chamber 21. The periphery 62 of cover 6 thus has a cone angle αp which is between 5° and 175°, and preferably substantially equal to 40°.

To assemble the heating device 1, the operator first applies the sealing element 8 to the side wall 24c of the opening 24 of the chamber 21, for example by depositing an annular bead of material. In a second step, the operator positions the cover 6 above the opening 24 of the chamber 21, and more precisely at the level of the beveled edge 24a of said opening. Finally, comes the step of pushing cover 6 into chamber 21 by means of a fitting tool.

The thrust of the cover 6 in the housing 2 causes the base 61 and the periphery 62 of said cover to come into contact respectively with the shoulder 24b and the side wall 24c of the opening 24 of the chamber 21. A tight fit between the cover 6 and the casing 2, without the need for an intermediate fixing element between said cover and said casing.

In addition, this thrust allows a distribution of the sealing element 8 at the interface between the cover 6 and the housing 2. In fact, the sealing element 8 is spread evenly, in particular between the side wall 24c of the opening 24 and the outer wall 62b of the cover 6, by the movement of said cover in the housing 2. In addition, the sealing element 8 fills the space formed between the recess 24d of the opening 24 and the elbow 63 of the cover 6. Thus, the sealing element 8 makes it possible to fill any surface defects present on the side wall 24c of the opening 24 and the outer wall 62b of the cover 6.

With such a distribution of the sealing element 8, favored by the forced fitting of the cover 6 in the casing 2, the heating device 1 according to the invention allows satisfactory sealing without having to use a removable gasket to compress.

Claims (10)

Electric fluid heating device (1), in particular intended for a vehicle, said device comprising:
- a fluid circulation box (2),
- at least one electric heating element (4),
- a lid (6) closing said box and carrying said electric heating element(s) (4),
characterized in that said cover (6) is mounted on said casing by force fitting so that said at least one electric heating element (4) extends into said casing (2). Heating device (1) according to the preceding claim, in which the cover (6) comprises a base (61) as well as a periphery (62), the said base comprising at its center a counter-form (64) forming with the said periphery depression (65). 3. Heating device (1) according to the preceding claim, wherein the against-form (64) is configured to receive the electrical heating element(s) (4). 4. Heating device according to claim 2 or 3, in which the casing (2) comprises an opening (24) having a side wall (24c) and a shoulder (24b), the base (61) and the periphery (62). of the lid (6) being in contact respectively with said shoulder (24c) and with said side wall (24c). Heating device (1) according to any one of the preceding claims, in which the electrical element (4) comprises a resistor (41) and an electrical connection terminal (42), said resistor (41) extending in the housing (2), said terminal (42) extending through the cover (6) on either side thereof. 6. Heating device (1) according to any one of the preceding claims, in which the cover (6) and the housing (2) form an interface provided at least partially with a sealing element (8). 7. Heating device (1) according to the preceding claim, in which the sealing element (8) comprises a film of polymeric material located at the level of the interface between the cover (6) and the casing (2). Heating device (1) according to the preceding claim, in which the polymeric material comprises an adhesive. 9. Heating device (1) according to any one of the preceding claims, in which the casing (2) defines a fluid circulation chamber (21), the electric heating element(s) (4) extending into said chamber. (21), said housing (2) comprising at least two connection members (22), (23) in fluid communication with said chamber (21). 10. Cover (6) for a casing (2) of a heating device (1) according to any one of the preceding claims, said cover comprising:
- a base (61),
- a periphery (62) extending from said base (61),
- at least one electric heating element (4),
said base (61) carrying the said electric heating element or elements,
characterized in that the cover (6) is intended to pass from a first configuration, before assembly, in which the said periphery has a flared shape, to a second configuration, after fitting in force, in which the said periphery (62) has a straightened form.