Patent Application
20050061268
The invention relates to the field of adjusted or controlled circulation of gaseous or liquid fluids in at least one circuit or length of pipe, and its subject is a pump/valve assembly and a cooling circuit including such an assembly.
A large number of devices for circulating a fluid in a circuit by controlling the flow rate with more or less precision are already known.
When relatively precise adjustment is required two solutions may be envisaged, namely adjusting the speed or power of the active member (the pump) by providing it with a converter or a drive which is continuously adjustable within the required ranges, or adding a flow-adjusting means with a movable element such as a valve or the like to an active element with limited or crude adjustment capacity (such as a pump operating at constant speed).
The first solution is relatively expensive owing to the type of motor and electronic control means needed for its use and the second solution, although less costly, often fails to provide the required precision in many applications, because the adjusting means used do not take the actual position of the movable element into account and/or do not allow for the physical changes affecting the mechanical parts of the devices.
In the latter case wear on the packing of the movable element and/or the contact surface of that element will lead to a shift in the fully-closed position of the adjusting device which will not be taken into account.
The object of the invention is to overcome the above disadvantages and to provide a high-precision adjusting assembly comprising a pump and at least one adjusting means at relatively low cost.
To this end its subject is an assembly forming part of a circuit for circulating a liquid fluid and comprising a pump and at least one valve unit with proportional control, in which the valve is mounted in series with said pump in that part of the circuit, characterised in that the valve unit comprises, apart from the valve itself, firstly an electrical actuator and a position sensor which are fixed to the movable member sealing the valve for displacement therewith, and secondly a control means controlling the actuator according to the position of the movable member indicated by the sensor and a reference signal, said valve unit being subjected to a procedure indexing the position of the movable member and setting parameters for the control means at the beginning of each new operating cycle of the assembly, and that the pump is rotated at a constant speed, if appropriate selected from a limited number of predetermined speeds, at least during part of each operating cycle of the pump.
The invention will be understood better from the following description which relates to preferred embodiments given as non-restrictive examples. These will be explained with reference to the accompanying diagrammatic drawings, in which:
The assembly as shown in the accompanying drawings comprises a pump 1 driven by a motor 1′ and at least one valve unit 2 with proportional control, in which the valve 3 is mounted in series with said pump in the part of the circuit which receives and is at least partly formed by said pump 1/valve unit 2 assembly.
In accordance with the invention the valve unit comprises, apart from the valve 3 itself, firstly an electrical actuator 4 and a position sensor 5 which are fixed to the movable member 3′ sealing the valve 3 for displacement therewith, and secondly a control means 6 controlling the actuator 4 according to the position of the movable member 3′ indicated by the sensor 5 and a reference signal, said valve unit 2 being subjected to a procedure indexing the position of the movable member 3′ and setting parameters for the control means 6 at the beginning of each new operating cycle of the assembly. The pump 1 is rotated at a constant speed, if appropriate selected from a limited number of predetermined speeds, at least during part of each operating cycle of the pump 1 (
The valve unit 2 will preferably correspond to an adjusting device as described in French patent application No. 0116633 filed 21 Dec. 2001 in Applicants' name, and will advantageously be controlled by a method also described in that application. The full contents of that specification are included herein by reference.
One feature of the invention is that the pump 1 is rotated by an electric motor 1′ with a constant speed or one which can operate at a plurality of predetermined fixed speeds. The prices of the motor 1′ and its supply and control circuits will consequently be lower.
In a preferred embodiment of the invention the pump 1 and valve 3 are incorporated in one and the same structural module 7.
A modular, single-block construction of the pump 1/valve 3 assembly of this type, which can be produced in compact, rigid form at low cost and with resistance to vibration and impact, is described for example in French patent application No. 0013844 of 27 October 2000 in the Applicants' name, and the contents of that application are included in this specification by reference.
The single-block structural module 7 advantageously comprises an intimate assembly of at least two parts made of a thermoplastic material, these parts in particular forming the casing of the pump 1 and the housing of the valve 3.
In an alternative embodiment of the invention shown in
The second valve unit 8 will thus have a construction and mode of operation substantially similar to those of the first valve unit 2.
In order to optimise fluid circulation, use the power consumed by the motor 1′ to the maximum and put the motor under a substantially constant load during its active periods in a given operating cycle, provision may advantageously be made for the first valve 3 and second valve 9 to be controlled so as to counteract each other, in such a way that the total resistance to the flow produced by the two valves 3 and 9 and their respective associated circuits (incorporating those valves) is substantially constant (a substantially constant sum of partial resistances).
As shown in
The movable member 3′ of the first valve 3 and, if appropriate, the movable member 9′ of the second valve 9 are preferably in the form of a butterfly valve or a rotary check valve mounted on a spindle.
As shown by way of example in
In a possible embodiment of the invention the circuit portion 13 including the means 13′ for cooling the engine 14 leads into at least two shunt circuits, namely a shunt circuit 15 incorporating the radiator 16 and the first valve 3 and a shunt circuit 15′ incorporating the heat exchanger 17 for the exhaust fumes and the second valve 9.
Finally, according to an additional feature of the invention, not only the pump 1 and valves 3 and 9 but also the heat exchanger 17, at least part of the circuit portion 13 and at least part of the shunt circuits 15 and 15′ may make up an integral part and be formed by one and the same structural module 18, e.g. comprising an assembly of a plurality of parts made of a thermoplastic material.
A cooling circuit in this form is also described and illustrated in the above-mentioned French patent application No. 0013844.
A circuit of this type may equally include a shunt circuit containing an all-or-nothing valve 19 extending through the liquid and de-gassing tank 20 and another shunt circuit supplying the radiator 21 which heats the body. At least some of these additional members may also be incorporated in the single-block structural module 18 (see
The invention is not of course restricted to the embodiments described and illustrated in the accompanying drawings. These may still be modified, particularly in respect of the structure of the various members or by substituting equivalent techniques, without thereby going beyond the scope of protection of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 0116759 | Dec 2001 | FR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP02/14573 | 12/20/2002 | WO |
