THERMOSTATIC VALVE HAVING A SLEEVE
This invention relates to a thermostatic valve for a fluid circulation circuit, in
particular coolant for a heat engine.
Valves provided with a sleeve for controlling of which the movement is controlled
by a thermostatic element typically equip cooling circuits associated with high-capacity
heat engines, in particular those used in lorries and certain motor vehicles, for which the
flows of coolant required for their operation are higher than those encountered for heat
engines with a lower capacity, for which the thermostatic valves used have flaps.
Indeed, using a sleeve in general makes it possible to have a stopper referred to
as balanced, i.e. a stopper for which the difference in the pressures on either side of the
wall of the sleeve is substantially zero according to the direction of movement of the
sleeve by the thermostatic element, with this direction corresponding in practice to the
axial direction of the sleeve. Inversely, in a thermostatic flap valve, the latter generally
15 extends in a plane perpendicular to the direction of movement of the flap by the
thermostatic element, in such a way that the pressure difference on either side of the flap
according to this direction reaches high values, in particular when the circulation of fluid is
interrupted by the flap. The energy required to separate such a flap from its seat is
therefore often substantial, and this all the more so when the flow of the liquid to be
20 controlled is substantial and flows in the direction of closing of the flap.
That said, current sleeve valves have however limits with regards to their
maximum allowable flow. One of the reasons is linked to a poor peripheral supply of the
sleeve: although in theory, the entire periphery of the sleeve could be made use of in
order to allow the flow of the fluid through this sleeve when the latter is open, it is
25 observed in practice that the _flow of fluid supplying the interior of the sleeve is
"channelled" through the opening of the inlet opening for this fluid into the housing of the
valve. Indeed, when the sleeve is opened, i.e. when the sleeve is separated from its
bearing seat defined by a wall of the valve housing, arranged axially across from the
sleeve, the fluid tends to transit through the sleeve by entirely and exclusively flowing in
30 the extension of the aforementioned opening. As such, EP-A-1 106 883, on which is
based the preamble of claim 1, provides an example of a three-way valve, wherein the
sleeve presses, via one of its axial ends, against a wall of the valve housing, separating
two circulation ducts of the fluid, between which the fluid tends to transit "in a straight line"
when the sleeve is separated from the aforementioned housing wall. The same applies for
35 the valves disclosed in DE-A-44 10 249, US-A-3 734 405, US-A-4 022 377,
FR-A-2 919 704 and US-A-2002/096571.
• 2
The purpose of this invention is to propose a thermostatic sleeve valve, authorising
a substantial maximum flow.
To this effect, the invention has for purpose a thermostatic valve for a fluid
circulation circuit, such as defined in claim 1.
5 The idea at the basis of the invention is to not press the sleeve directly against a
wall of the housing, but to create, according to the flow path of the fluid between the inlet
and outlet openings, a free space between the bearing seat of this sleeve and one of
these openings. This free space in fact allows the fluid to be distributed, inside the
housing, according to the periphery of the sleeve in such a way that, when the latter is
10 open, the fluid flows between this free space and the interior of the sleeve, over the entire
periphery of the latter. In particular, when the aforementioned opening is an inlet opening
for the fluid in the housing, this amounts to saying that the free space is a supply space
upstream of the seat, making it possible to supply the sleeve well over its entire periphery.
According to the invention, this free space is defined using a part qualified as a seat part
15 since it defines the bearing seat of the sleeve, which is fixedly mounted inside the
housing, with axial interposition of the free space. The setting up of this seat part in the
housing is quick and easy, by being for example carried out at the same time as the
setting up of at least one other component of the valve, which does not extend the
assembly duration assembly time of the valve. Thanks to this seat part, more precisely to
20 the free space that is defines axially in alignment with the sleeve, the valve takes in a high
maximum flow of fluid.
25
Additional advantageous characteristics of the valve in accordance with the
invention, taken separately or according to all of the combinations that are technically
possible, are specified in the dependent claims 2 to 10.
The invention shall be better understood when reading the following description,
provided solely by way of example and in reference to the drawings wherein:
- figure 1 is a perspective view of a valve in accordance with the invention, shown
as a half cross-section;
- figure 2 is a cross-section view of the valve of figure 1, in a section plane different
30 to that of figure 1;
35
- figures 3 and 4 are perspective views, under different respective angles, of a seat
part belonging to the valve of figure 1; and
-figure 5 is a perspective view of a part of a retaining part belonging to the valve of
figure 1.
Figures 1 and 2 show a valve 1 adapted to control the circulation of a fluid,
entering into a housing 10 of the valve via an opening 11 and existing from this housing by
3
an opening 12, after having passed through a regulating chamber 13 wherein the
openings 11 and 12 exit. In this chamber 13 are arranged a mobile sleeve 20, a fixed seat
part 30 and a thermostatic element 40 for controlling the movement of the sleeve with
regards to the seat part. The valve 1 is for example used in a cooling circuit of a heat
5 engine of a vehicle.
The sleeve 20 has a generally tubular shape, centred on a longitudinal axis X-X
through which pass the section planes of figures 1 and 2. This sleeve is arranged in the
chamber 13 in such a way that the opening 11 exists into this chamber in a way that is
substantially perpendicular to the axis X-X, while, in the example embodiment being
10 considered here, the opening 12 is globally centred on this axis.
The sleeve 20 comprises a cylindrical main body 21, centred on the axis X-X and
with a circular base, of which the wall is solid over its entire periphery. At the axial end
20A of the sleeve, turned to the side of the opening 11, the body 21 is provided with an
internal peripheral edge 22 from which arms 23 extend rigidly in the direction of the axis
15 X-X. At their free end, these arms 23 are connected fixedly to a heat-conducting cup 41 of
the thermostatic element 40, containing a thermoexpandable material, such as a wax.
This cup 41, which extends in length in a centred manner over the axis X-X, receives
interiorly a rod 42, which itself also extends in length in a centred manner over the axis XX
and which is also able to be deployed and to be retracted, via translation according to
20 this axis, with regards to the interior of the cup 41, under the effect of a variation in the
volume of the thermoexpandable material. In the portion of its end arranged to the exterior
of the cup 41, the rod 42 is fixedly connected to the housing 1 0 by known arrangements,
such as by overmoulding, press fitting and/or gluing, which will not be described any
further herein.
25 Advantageously, in the example embodiment considered here, an electric heating
resistance, not visible in the figures, is arranged inside the rod 42, carried out in this case
in the form of a metal tube, in such a way that this resistance can, when it is supplied with
electricity, heat the thermoexpandable material contained in the cup 41. The housing 1 0 is
then exteriorly provided with a base 14 (figure 2) for connecting an external electrical
30 power source, from which the electrical conductors extend to the terminals of the
aforementioned heating resistance, being for example embedded in a insulating resin 15
added exteriorly to the housing 10.
It is understood that, when the thermoexpandable material contained in the cup 41
is heated up, its expansion causes the translation of the cup 41 along the axis X-X, in the
35 direction opposite to the rod 42, i.e. downwards in figures 1 and 2. Doing this, the cup 41
4
drives according to a corresponding translation movement the sleeve 20, as indicated by
arrow F in figure 2.
According to the axial position of the sleeve 20, controlled by the thermostatic
element 40, the axial end 20A of this sleeve is more or less separated from an associated
5 wall 31 belonging to the seat part 30. More precisely, this wall 31 has the general shape of
a solid disc, centred on the axis X-X and with a circular base that is substantially identical
to that of the body 21 of the sleeve 20. On its surface directed towards the sleeve 20, this
wall 31 defines a peripheral edge constituting a sealed bearing seat 32 for the edge 22 of
the sleeve 20: in the axial position of the sleeve 20 shown in figures 1 and 2, the edge 22
10 is as such pressed against the seat 32 of the wall 31, this edge and this seat thus
cooperating via the complementarity of the shapes along their entire periphery, in such a
way as to cut a flow of fluid between the exterior and the interior of the sleeve 20.
As can be easily seen in figures 3 and 4, the wall 31 has a through bore 33 centred
on the X axis-X and adapted to receive in a sealed manner the rod 42, as shown in figure
15 1. As such, as shown in figures 1 and 2, in the housing 10, the wall 31 is arranged in such
a way that its central region is located axially pressing against an internal allowance 16 of
the housing 10, to which the rod 42 is fixedly connected and through which the electric
heating resistance internal to this rod is supplied with electricity.
On the other hand, the peripheral region of the wall 31 is not pressing against the
20 housing allowance 16, but, on the contrary, is separate, according to the direction of the
axis X-X, from the wall of the housing 10 from which this allowance 16 extends protruding
towards the interior of the chamber 13. In this way, the peripheral region of the wall 31
and the aforementioned wall of the housing 1 0 define between them, according to the
direction of the axis X-X, a free space V, which belongs to the chamber 13, which
25 surrounds the housing allowance 16 and which, in the example embodiment considered
here, has a global annular shape, centred on the axis X-X.
As can be easily seen in figure 1, the opening 11 opens freely into the free space
V: moreover, in the embodiment considered here, the free space Vis located, according
to a direction perpendicular to the axis X-X, in the straight extension on the one hand
30 substantial, approximately half, of the opening of opening 11 into the chamber 13.
Advantageously, the surfaced of the wall 31, which defines the free space V, is provided
with reinforcement ribs 34, easily seen in figure 4.
In service, when the opening 11 is supplied with fluid to be controlled by the valve
1, this fluid penetrates into the chamber 13, filling at least partially the free space V: the
35 fluid is as such distributed over the entire periphery of the sleeve 20 in such a way that,
when this sleeve is moved from its closed position, shown in figures 1 and 2, to an open
5
position in which its end 20A is axially distant from the seat 32, the fluid flows inside the
sleeve 20, passing between the arms 23, and this over the entire periphery of the sleeve.
It is understood that the valve 1 is capable of taking in a substantial flow of fluid passing
through it, with the entire periphery of the sleeve being made use of to authorise the flow
5 of fluid through this valve when the sleeve is in open position. The interest of the ribs 34 is
thus to avoid a significant deformation of the wall 31, under the action of a high flow of
fluid.
Moreover, the seat part 30 advantageously includes a crown 35 which, as can be
easily seen in figures 3 and 4, is co-axial to the wall 31, while being located at a different
10 axial level from the latter. Elbow arms 36, distributed in a substantially regular manner
according to the periphery of the seat part 30, rigidly connect the wall 31 and the crown
35. In the valve 1, as shown in figures 1 and 2, the crown 35 is arranged is such a way, on
the one hand, as to be located axially between the openings 11 and 12 and, on the other
hand, to be radially interposed between the body 21 of the sleeve 20 and the housing 10.
15 According to its external periphery, the crown 35 forms with the housing 10 a fixed
contact, sealed by a seal 37 which, in the example embodiment shown, is retained in a
peripheral gorge 38 of the crown. On its inner periphery, the crown 35 forms with the body
21 of the sleeve 20 an axially sliding contact, sealed by a lip seal 39. This lip seal 39 is
received in a complementary peripheral indentation 310 of the crown 35.
20 As such, the crown 35 insulates in a sealed manner the openings 11 and 12 one in
25
relation to the other, around the sleeve 20. In other words, to the exterior of this sleeve,
the crown 35 compartmentalises the chamber 13 into two separate portions in a sealed
manner, with one of them in free communication with the opening 11 while the other in
communication with the opening 12.
In service, when the opening 11 is supplied with fluid to be controlled by the valve
1, the crown 35 reinforces the effect of the wall 31 described hereinabove, allowing for the
supplying of the sleeve 20 over its entire periphery: indeed, with regards to the radial
dimension of the crown 35, the free space V of peripheral supply of the sleeve 20 is,
somewhat, extended axially all around this sleeve, as such increasing the maximum
30 allowable flow of the valve 1. When the sleeve 20 is in its open position, the fluid
penetrates inside this sleeve, passing between the arms 36, without the latter inducing
any significant resistance to the flow, in light of their low thickness.
In practice, the seat part 30 also has the interest of being able to be mounted
quickly and easily inside the housing 10, provided beforehand with the joint 37 and the lip
35 seal 39. In addition, as in the example embodiment considered in the figures, this seat
part 30 is manufactured beforehand in a single part, in particular via moulding a plastic
• 6
material. In terms of an alternative not shown, the seal 37 and/or lip seal 39 are directly
overmoulded on the seat part 30.
As an advantageous option, the crown 35 incorporates a degassing function. More
precisely, as shown in figure 2, the crown 35, according to the direction of the axis X-X,
5 has a through bore 311 of which the outlet, on the side of the opening 11, can be sealed
with a ball 312. This ball can be moved in relation to the crown 35, being retained by a
cage 313, integral with the crown, here integrally formed with the latter. In this way, when
the opening 11 is supplied with a fluid to be controlled by the valve 1, this fluid presses the
ball 312 against the outlet of the hole 311, thus blocking the latter in a sealed manner. On
10 the other hand, when the air is trapped inside the housing 10, on the side of the opening
12, in particular during the filling under pressure of the circuit wherein the valve 1 is
incorporated, for its initial putting into service or following maintenance intervention, while
the sleeve 20 is in its closed position, the ball 312 allows this trapped air to escape into
the portion of the chamber 13 in communication with the opening 11.
15 Moreover, the valve 1 further comprises a return spring 50 of the cup 41 towards
the rod 42, arranged co-axially around this cup. This spring 50 is retained in relation to the
housing 10 by a part 60 which, advantageously, also provides for the retaining of the seat
part 30.
More precisely, as can easily be seen in figure 5, this retaining part 60 includes an
20 annular crown 61, which is centred on the axis X-X and against which is pressed the end
of the spring 50, opposite that bearing against the cup 41. The retaining part 60 further
comprises two arms 62 which extend from two diametrically opposite zones 62A of the
collar 61. Opposite the crown 61, each arm 62 includes an end portion 628 forming a lug
fixedly connected to the housing 10, being received in a complementary cavity 17 defined
25 interiorly by the housing, as shown in figures 1 and 2. Advantageously, the peripheral
dimension of this end portion 628 is substantially equal to that of the cavity 17 for the
purposes of the relative blocking in rotation around the axis X-X, by adjusting shapes.
Between its end portions 62A and 628, each arm 62 has an elbowed running
portion 62C having globally the shape of a U turned towards the opening 12: the bottom of
30 this U shape is adapted to axially support the crown 35 of the seat part 30,
advantageously by retaining the lip seal 39 in its reception indentation 310. To do this, the
running portion of arm 62C has, on its surface directed towards the opening 11 , a
complementary surface 63 of the surfaces across from the crown 35 and of the lip seal 39.
Advantageously, the aforementioned surface of the crown 35 is arranged at the bottom of
35 an indentation 314 of this crown, of which the peripheral dimension is substantially equal
• 7
to that of the surface 63 of the arm 62 for the purposes of relative blocking in rotation
around the axis X-X, by adjusting shapes.
Of course, U shape of the running portion 62C of the arms 62 is provided in order
to not interfere with the body 21 of the sleeve 20 during translational movements of the
5 latter according to the axis X-X.
In order to facilitate the setting up of the retaining part 60 inside the housing 10,
this part 60 has a capacity of elastic deformation radially to the axis X-X: in practice, in the
example embodiment considered here, this amounts to say that each lug 628 is pulled
back elastically against the running portion 62C during the axial introduction of the part 60
10 inside the housing 10, then, after the release of this lug, the latter is introduced into the
receiving cavity 17, via the elastic return effect.
Various arrangements and alternatives to the thermostatic valve 1 described until
now can moreover be considered. By way of example:
- as a complement or as a replacement to the axial retaining action of the seat part
15 30 by the retaining part 60, the part 30 can be fixed directly to the housing 1 0 by any
suitable mechanical means; in order to show this alternative, figure 1 shows that the
allowance 16 of the housing 10 defines, in its surface against which the wall 31 is
pressing, two holes 18 for receiving fastening screws not shown, noting that these holes
18 are drawn in axial alignment with two socket screws 315 defined in the surface of the
20 wall 31 turned towards the sleeve 20, these socket screws as such making it possible to
locate and to facilitate the setting into place of the aforementioned screws;
- the geometry of the housing 10 can be modified in relation to that considered in
the figures, in particular to adapt to the installation environment of the valve 1 and/or in
order to facilitate the manufacture thereof; moreover, at least one other opening can be
25 provided in addition to the opening 11 in order to supply the valve with fluid; likewise, at
least one other opening than the opening 12 can be provided for the outlet of the fluid; in
this later case, in a manner known per se, the cup 41 of the thermostatic element 40 can
be prolonged by a bar carrying a mobile flap for the purposes of controlling the adjustment
of the circulation of the fluid between the various outlet openings, in particular in order to
30 provide a by-pass function in the cooling circuit of a heat engine;
- the valve 1 can be used in cooling circuits with a direction of circulation of the
fluid that is inversed in relation to that described until now, i.e. with a fluid inlet at least via
the opening 12 and a fluid outlet at least via the opening 11;
-other embodiments than the ball 312 can be considered in order to constitute, on
35 the crown 35, a mobile valve for cutting off the degassing hole 311; and/or
• 8
- the shape and the number of arms 62 of the retaining part 60 are not limited to
those shown in the figures; as such, by way of example, the shape of these arms 62 can
be provided as substantially planar, rather than of a U shape; and/or
- the thermostatic element 40 can be functionally linked to the rest of the valve 1 in
5 a manner that is inverse to that considered in the example shown in the figures; in other
words, in this case, it is the cup 41 which is fixedly connected to the housing 10 while the
rod 42 pushes on the sleeve 20 in order to drive it in movement; such an arrangement can
in particular be considered when it is renounced to control the valve 1 via a electric
heating resistance, internal to the rod 42.

CLAIMS
1. Thermostatic valve (1) for a fluid circulation circuit, in particular of coolant for a
heat engine, comprising:
5 - a housing (10) defining openings (11, 12) for the inlet and outlet of a fluid
circulating through the housing,
- a sleeve (20) for controlling the circulation of the fluid through the housing, this
sleeve defining a central axis (X-X) according to which the sleeve is mobile in relation to
housing between a closed position, wherein an axial end (20A) of the sleeve is pressed in
10 a sealed manner against a fixed seat (32) in relation to the housing in order to cut off a
flow of the fluid between two (11, 12) of the openings, and an open position, wherein the
end of the sleeve is axially separated from the seat in order to authorise the flow, and
- a themnostatic element (40), containing a thermoexpandable material and
comprising a fixed portion (42), which is fixedly connected to the housing (10), and a
15 mobile portion (41) which can be displaced in relation to the fixed portion under the effect
of a variation in the volume of the thermoexpandable material and vWiich is kinetically
linked to the sleeve (20) in such a way as to control the movement of the sleeve between
its closed and open positions,
characterised in that the valve further includes a seat part (30), which is fixedly mounted in
20 the housing (10) and which includes a fluid-tight wall (31), of which one of the two
opposite surfaces extending transversally to the axis (X-X) of the sleeve (20) defines said
seat (32) while the other of these two opposite surfaces defines, between it and a wall of
the housing (1) according to the direction of the axis (X-X) of the sleeve (20), a free space
(V) wherein exits one (11) of said two openings (11, 12) and through which the fluid flows
25 being distributed over the entire periphery of the sleeve (20) when this sleeve is in its
open position.
2. Valve according to claim 1, characterised in that the opening (11) associated
with the free space (V) exits into this free space in a manner that is substantially
perpendicular to the axis (X-X) of the sleeve (20).
30 3. Valve according to one of claims 1 or 2, characterised in that the fixed portion
(42) of the thermostatic element (40) axially passes through in a sealed manner the
sealed wall (31) of the seat part (30).
4. Valve according to any of the preceding claims, characterised in that, in a
transversal cross-section to the axis (X-X) of the sleeve (20), the sealed wall (31) of the
35 seat part (30) and the main tubular body (21) of the sleeve have respective exterior
profiles which are coaxial and substantially identical.
10
5. Valve according to any of the preceding claims, characterised in that the seat
part (30) includes a crown (35), which is located axialiy between said two openings (11,
12) and which is radially interposed between the sleeve (20) and the housing (10) in such
a way as to fonri, according to its external periphery, a sealed fixed contact with the
5 housing as well as, according to its internal periphery, a sliding sealed contact with the
sleeve.
* J, /^' 6. Valve according to claim 5, characterised in that the sealed wall (31) and the
crown (35) of the seat part (30) are coaxial and connected together by elbow arms (36)
distributed in a substantially regular manner around their common axis (X-X).
10 7. Valve according to one of claims 5 or 6, characterised in that the crown (35) is
interiorly provided with a peripheral lip seal (39).
8. Valve according to any one of claims 5 to 7, characterisid in that the crown (35)
defines a degassing hole (311) which passes through the crown according to the direction
of the axis (X-X) of the sleeve (20), and in that the crown is provided with a valve (312) for
15 cutting off the degassing duct, which can be moved in relation to the crown under the
action of the fluid.
9. Valve according to any of the preceding claims, characterised in that it further
comprises a retaining part (60), which is fixedly connected to the housing (10) and which
is adapted to axialiy support both the seat part (30) and a return spring (50) of the mobile
20 portion (41) towards the fixed portion (42) of the thermostatic element (40).
10. Valve according to claim 9, characterised in that the retaining part (60)
includes arms (62) distributed around the axis (X-X) of the sleeve (20), each arm having:
- a first end portion (62A) which absorbs the constra^te produced by the return
spring (50),
25 - a second end portion (62B), opposite the first end portion, which cooperates
mechanically with the housing (10) for the purposes of.fastening, and
- a running portion (62C) globally conformed as a U against the bottom of which
axialiy beats the seat part (30), in particular its crown (35) and/or its lip seal (39).