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US-20260126820-A1 - THERMOSTATIC VALVE HAVING A SLEEVE

US20260126820A1US 20260126820 A1US20260126820 A1US 20260126820A1US-20260126820-A1

Abstract

A valve includes a thermostatic element made of thermally expandable material, including a fixed part, fixedly connected to a housing, and a movable part, movable along an axis. The valve further includes a plug movable axially relative to a plug seat, fixedly supported by the housing, to control a flow of fluid between two chambers of the housing. The valve further includes a sleeve movable along the axis between a first configuration, wherein the sleeve is pressed against a sleeve seat fixedly supported by the housing distinctly from the plug seat, to prevent the fluid from flowing between the two chambers, and a second configuration, wherein the sleeve is moved away from the sleeve seat. The plug is connected to the movable part and to the sleeve so that during the expansion of the thermally expandable material, the movable part opens the plug to an intermediate position.

Inventors

  • Guillaume Gautier Graindorge
  • Thierry Maraux

Assignees

  • VERNET

Dates

Publication Date
20260507
Application Date
20230628
Priority Date
20220629

Claims (11)

  1. 1 . A thermostatic valve comprising: a housing inside which are arranged first and second chambers which are configured to be directly connected to each other so that a fluid flows inside the housing and are each configured to be connected directly to an outside of the housing so that a fluid enters the housing and/or leaves the housing via the chambers concerned, wherein said housing fixedly supports two distinct seats namely a plug seat, and a first sleeve seat; a thermostatic element, which includes a fixed part fixedly connected to the housing, and a movable part movable along an axis relative to the fixed part, the fixed part and movable part axially moving away from each other under an action of an expansion of a thermally expandable material of the thermostatic element; a plug which is movable along the axis relative to the housing in order to change between a closed configuration, wherein the plug is axially pressed against the plug seat, so as to prevent the fluid from flowing between the first and second chambers, by passing through the plug seat, and an open configuration wherein the plug is moved away from the plug seat so as to let the fluid flow between the first and second chambers by passing through the plug seat; and a sleeve which is movable along the axis relative to the housing to change between a first configuration, wherein the sleeve is pressed axially against the first sleeve seat, so as to prevent the fluid from flowing between the first and second chambers by passing through the first sleeve seat, and a second configuration, wherein the sleeve is moved away from the first sleeve seat so as to let the fluid flow between the first and second chambers by passing through the first sleeve seat, wherein the plug is connected to the movable part of the thermostatic element and to the sleeve so that during the expansion of the thermally expandable material; the movable part drives the plug along the axis with respect to the housing from the closed configuration to the open configuration, until the plug occupies a predetermined intermediate position, whereas the sleeve is immobile with respect to the housing, staying in the first configuration thereof, then the plug in the open configuration is driven along the axis with respect to the housing by the movable part beyond the predetermined intermediate position, while driving the sleeve along the axis with respect to the housing from the first configuration to the second configuration.
  2. 2 . The thermostatic valve according to claim 1 , wherein, in orthogonal projection onto a geometric plane perpendicular to the axis, the plug seat is inscribed inside the first sleeve seat.
  3. 3 . The thermostatic valve according to claim 1 , wherein the plug is fixedly connected along the axis to the movable part of the thermostatic element, and wherein the sleeve is assembled with the plug freely slidable along the axis when the plug is driven between the closed configuration and the predetermined intermediate position, and fixedly along the axis when the plug in the open configuration is driven beyond the predetermined intermediate position.
  4. 4 . The thermostatic valve according to claim 3 , wherein the plug has an armature which is directly mounted around a movable part of the thermostatic element securely along the axis, and wherein the sleeve includes an armature which is mounted around the armature of the plug so as to leave freely sliding, along the axis, the armature of the sleeve and the armature of the plug one with respect to the other when the thermostatic valve is driven between the closed configuration and the predetermined intermediate position, and to connect fixedly along the axis the armature of the sleeve and the armature of the plug one to the other, by axial bearing when the thermostatic valve in the open configuration when the thermostatic valve is driven beyond the predetermined intermediate position.
  5. 5 . The thermostatic valve according to claim 1 , wherein the thermostatic valve further includes: a first return spring, which is compressed along the axis and which is interposed, directly or indirectly, between the housing and the plug so as to drive the plug from the open configuration to the closed configuration during a contraction of the thermally expandable material, and a second return spring, which is compressed along the axis and which is interposed, directly or indirectly, between the housing and the sleeve so as to drive the sleeve from the second configuration to the first configuration during the contraction of the thermally expandable material.
  6. 6 . The thermostatic valve according to claim 5 , wherein the thermostatic valve includes a support bracket against which the first return spring and the second return spring are axially pressed, said support bracket being fixedly connected to the housing and extending substantially parallel to the axis from the housing inside the sleeve.
  7. 7 . The thermostatic valve according to claim 5 , wherein the housing incorporates a support part against which the first return spring and the second return spring are axially pressed, said support part extending transversely to the axis and being arranged entirely outside the sleeve.
  8. 8 . The thermostatic valve according to claim 1 , wherein the housing is provided with at least one orifice which: connects the second chamber and the outside of the housing along a direction substantially radial to the axis (X-X), is left uncovered by the sleeve in the first configuration so as to allow the fluid to flow radially to the axis between the second chamber and the outside of the housing via said at least one orifice, and is covered, along the direction substantially radial to the axis, by the sleeve in the second configuration so as to prevent the fluid from flowing radially to the axis between the second chamber and the outside of the housing via said at least one orifice.
  9. 9 . The thermostatic valve according to claim 8 , wherein the housing fixedly supports a second sleeve seat, wherein the sleeve in the first configuration is moved away from the second sleeve seat, and wherein, during the expansion of the thermally expandable material, the sleeve in the second configuration is axially driven relative to the housing by the plug until bearing axially against the second sleeve seat so as to prevent the fluid from flowing through at least one second chamber and said at least one orifice by passing through the second sleeve seat.
  10. 10 . The thermostatic valve according to claim 9 , wherein the thermostatic valve includes an overtravel system which, during the expansion of the thermally expandable material, allows the movable part to move away from the fixed part of the thermostatic element while the sleeve is axially pressed against the second sleeve seat.
  11. 11 . The thermostatic valve according to claim 1 , wherein the housing is provided with a deflector which breaks fluid flows grazing the plug seat transversally to the axis.

Description

The present invention relates to a thermostatic sleeve valve. Thermostatic sleeve valves are valves with a sleeve, which controls the flow of a fluid through the valve housing and is controlled in displacement by a thermostatic element designed to move and thereby mechanically drive the sleeve depending on the temperature to which the thermostatic element is subject. Thermostatic sleeve valves typically equip cooling circuits belonging to motorizations of large cubic capacities, in particular same used in trucks and certain motor vehicles, for which the flow-rates of cooling fluid necessary for the operation thereof are higher than same encountered for motorizations of smaller cubic capacities, for which the thermostatic valves used are rather plug valves. In fact, the sleeve is a so-called balanced shutter, i.e. a shutter for which the difference in the pressures prevailing on either side of the tubular body of the sleeve is substantially zero according to the direction of displacement of the sleeve by the thermostatic element. On the other hand, the flap is a shutter, the generally flat body of which extends generally perpendicular to the direction of displacement of the plug by the thermostatic element, so that the difference in the pressures prevailing on either side of the flap along said direction reaches high values, especially when the flow of fluid is interrupted by the plug. Thereof being said, existing thermostatic sleeve valves have the drawback that, at the opening thereof, i.e. when the sleeve is driven by the thermostatic element from a closed configuration, where the sleeve is pressed axially against a seat to prevent fluid flow from passing through the seat, to an open configuration, where the sleeve is moved away from the seat to allow fluid to flow through the seat, the fluid flow-rate suddenly changes from a zero value to a substantial value. Such a variation in flow downstream of the seat associated with the sleeve can be detrimental to regulation by the thermostatic element and, more generally, to the stability of flows in the cooling circuit to which the valve belongs. In other words, the opening of thermostatic sleeve valves is not gradual or is just slightly gradual. To overcome such problem, a well-known solution is to reduce as much as possible the speed of displacement of the sleeve by the thermostatic element when the sleeve changes from the closed configuration to the open configuration, but it is difficult to control the speed of displacement precisely, especially since the diameter of the tubular body of the sleeve can be large. It is also possible to envisage a solution with throttling, i.e. with a passage section with progressive opening as a function of the travel of the sleeve, which is expensive to implement and limited in terms of result. Another solution is to dispense with the use of a sleeve in favor of plurality of staged plugs, which nevertheless induces economic constraints, as well as constraints in the design of the valve. U.S. Pat. No. 2017/220056 discloses a thermostatic valve having a geometric longitudinal axis. The valve comprises both a thermostatic element, including a movable piston and a fixed thermosensitive body, and two valve units, namely a first valve unit and a second valve unit, which are axially movable relative to each other. More precisely, the first valve unit comprises a first tubular body, which is centered on the axis and which, at one of the axial ends thereof, fixedly supports a first seat. The first valve unit further comprises a first shutter, which is movable in translation along the axis relative to the first tubular body so as to bear against/move away from the first seat to respectively interrupt/allow a first fluid flow. To this end, the first shutter is fixedly connected to the piston of the thermostatic element, whereas a first return spring is interposed axially between the first shutter and the first tubular body, so that the first shutter moves away from the first seat when the thermostatic element deploys, overcoming the resistance of the first return spring. The second valve unit comprises a second tubular body, which is centered on the axis and which fixedly supports a second seat. The second valve unit further comprises a second shutter which is axially movable in translation relative to the second tubular body so as to bear against/move away from the second seat to correspondingly interrupt/permit a second flow of fluid which is different from the first flow of fluid. To this end, provision is made for (i) the second tubular body to be fixedly connected to the thermosensitive body of the thermostatic element, (ii) the second shutter to be fixedly connected to the first tubular body of the first valve unit, (iii) the first tubular body to be mounted so as to be movable in translation along the axis inside of the second tubular body of the second valve unit, and (iv) a second return spring to be axially interposed between