FR2722841A1 - HYDAULIC FLUID DISTRIBUTION SYSTEM FOR HYDRAULIC CIRCUIT TESTING AND CHECKING - Google Patents

Abstract

The installation according to the invention comprises an auxiliary circuit for producing pressurized hydraulic fluid (G), the high pressure inlet (DHP) and low pressure return (RBP) ducts of which are connected by means of connecting circuits or more pairs of connectors (CD1, CD2 - C'D1, C'D2 - C "D1, C" D2) to each of which a circuit to be tested can be connected. Each link circuit includes an auxiliary self-pressurized tank comprising a high pressure cylinder (V'H1, V'H2, V'H3), a low pressure cylinder (V'B1, V'B2, V'B3) and a rigid link connecting the pistons of these two jacks (V'H1, V'B1 - V'H2, V'B2, V'H3, V'B3). The invention applies in particular to the control and testing of hydraulic circuits used in combat aircraft.

Description

HYDRAULIC FLUID DISTRIBUTION SYSTEM FOR

  TEST AND CONTROL OF HYDRAULIC CIRCUITS.

  The present invention relates to a hydraulic fluid distribution installation, usable for carrying out tests or checks of hydraulic circuits. It relates more particularly to tests or checks carried out on closed-loop hydraulic circuits, which use self-pressurized hydraulic tanks or "tarpaulins", constituted by at least two jacks respectively placed in the high and low pressure parts of the hydraulic circuit considered. and whose pistons are coupled to each other by a rigid connection so as to obtain the following equilibrium conditions: Ps = pS relation in which P is the high pressure, p is the low pressure, S is the section low pressure cylinder

  and s is the section of the high pressure cylinder.

  Hydraulic systems of this type are commonly used in combat aircraft designed to fly in

- 2 - 2722841

  taking very varied attitudes and which are subject to

  intense omnidirectional accelerations.

  Usually, the ground control of the hydraulic circuits of aircraft of this type is carried out by means of test benches comprising, for each circuit to be tested, an auxiliary hydraulic circuit which can be connected in parallel to the high pressure pump of the circuit to be tested. , so that it can replace the latter. This auxiliary circuit essentially comprises a high-pressure auxiliary pump, filters and a reservoir of hydraulic fluid of sufficient

large volume.

  Test benches of this type make it possible to carry out tests, or even treatments of hydraulic fluid, on aircraft arranged in locations (for example inside premises) which do not allow a

  starting of the aircraft engine.

  In order to reduce costs, it has already been proposed to produce hydraulic fluid distribution installations, comprising an auxiliary circuit of the above type on which several circuits can be connected

  hydraulics that can belong to several aircraft.

  However, it turns out that this solution is only operational in the case where the hydraulic circuits to be tested include atmospheric hydraulic fluid reservoirs at a regulated level. On the other hand, it is not suitable in the case of hydraulic circuits equipped with self-pressurized tanks such as those

previously mentioned.

  In fact, when several circuits to be tested are arranged in parallel on the auxiliary circuit, it can be seen that consumption of fluid by one of the circuits generates disturbances on the others.

- 3 - 2722841

  circuits, so that the whole becomes unstable and subject to possibly harmful uncontrolled phenomena. The invention therefore more particularly aims to solve this problem in order to be able to distribute the hydraulic fluid to several circuits to be tested, from the same auxiliary circuit, and this, avoiding any disturbance of one of the circuits under test. by the

other circuits.

  To this end, it therefore proposes a distribution installation comprising an auxiliary circuit for producing pressurized hydraulic fluid, the high and low pressure ducts of which are connected to a plurality of pairs of high and low pressure connectors by means of circuits for respective link, each pair of connectors can be connected to a circuit to be tested comprising a reservoir

  self-pressurized hydraulic of the above type.

  According to the invention, this installation is characterized in that each connection circuit comprises an auxiliary self-pressurized tank comprising two respective cylinders, namely: a high pressure cylinder, connected to the high pressure circuit of the auxiliary circuit and a low pressure cylinder connected to the low pressure circuit of said auxiliary circuit, the pistons of these two cylinders

  being connected to each other by a rigid connection.

  Advantageously, the ratio of the surfaces of the pistons of the cylinders of the auxiliary self-pressurized tanks is different from that of the cylinders constituting the tanks.

  self-pressurized circuits under test.

  Thus, in the case where the surface ratio of the auxiliary tanks is greater than that of the tanks of the circuits under test, the piston of the jack

- 4 - 2722841

  high pressure of the tanks of the circuits under test is held in high stop, while the piston of the jack

  low pressure is in support in low stop.

  Conversely, the abovementioned surface ratio could be chosen so that the piston of the high pressure cylinder of the tanks of the circuits under test is held in low stop, while the piston of the cylinder

  low pressure is in support in high stop.

  In addition, the flow of hydraulic fluid delivered to the

  low pressure cylinder outlet of each self-contained tank

  pressurized auxiliary can be regulated according to the position of the connecting member connecting the two

pistons.

  An embodiment of the invention will be described below, by way of nonlimiting example, with reference to the appended drawing in which: The single figure is a schematic representation of a hydraulic fluid distribution installation on which are connected three hydraulic circuits that can

  belong to three different aircraft.

  In this example, the three hydraulic circuits under test (blocks B1, B2, B3) include a hydraulic pump P1, P2, P3, a self-pressurized tank comprising a low pressure cylinder VB1, VB2, VB3, a high pressure cylinder VH1, VH2, VH3, and a receiver circuit Ri, R2, R3. The pistons of each of the pairs of cylinders VB1, VH1 - VB2, VH2 - VB3, VH3 which constitute a reservoir

  are connected by a rigid link L1, L2, L3.

  The low pressure cylinder VB1, VB2, VB3 is connected to the intake pipe of the pump Pl, P2, P3 as well as to a connector C'i, C'2, C'3 able to be connected to an element

- 5 - 2722841

  corresponding connection CD2, C'D2, C "D2 of

the ID distribution facility.

  The high pressure cylinder VH1, VH2, VH3 is, for its part, connected to the high pressure outlet of the pump P1, P2, P3 and to a connector C1, C2, C3 capable of being connected to a corresponding connection element CD1, C'D1, C "D1 of

installation ID.

  The receiving circuit Ri, R2, R3 receives the high pressure fluid coming from the high pressure cylinder VH1, VH2, VH3 and returns it, after use, to the low cylinder

pressure VB1, VB2, VB3.

  The distribution installation includes, like a conventional test bench, a hydraulic fluid production circuit comprising a high pressure hydraulic fluid generator G equipped with all the usual accessories. This generator G has been represented diagrammatically in the figure by a high pressure pump HP whose inlet inlet E is connected to a hydraulic fluid tank R supplied by a low pressure return circuit RBP and whose outlet S

  delivers on a DHP high pressure distribution circuit.

  The connection between the high and low pressure circuits DHP, RBP of the installation ID and those of each of the circuits to be tested B1, B2, B3, is carried out by means of an independent connection circuit comprising a self-pressurized tank comprising a high pressure cylinder V'H1, V'H2, V'H3, a low pressure cylinder V'B1, V'B2, V'B3 and a rigid connection L'l, L'2, L'3 connecting the pistons of

  these two cylinders V'B1, V'H1 - V'B2, V'H2 - V'B3, V'H3.

  The inputs of the high pressure cylinders V'H1, V'H2, V'H3 are connected to the high pressure distribution circuit DHP, while their outputs are respectively connected to the intake conduits CAl, CA2, CA3 of the circuits under

- 6 - 2722841

  test B1, B2, B3 by means of connection elements CD1, C'D1, C "D1 coming to connect on the

connectors Ci, C2, C3.

  The connectors C1, C2, C3 as well as the connection elements CD1, CD2, CD3 are provided with normally closed valves opening at the time of connection and being

  then closing, upon disconnection.

  The inputs of the low pressure cylinders V'B1, V'B2, V'B3 are respectively connected to the return conduits CR1, CR2, CR3 of the circuits under test via connection elements CD2, C'D2, C " D2 coming

  connect on connectors C '!, C'2, C'3.

  Each low pressure cylinder V'B1, V'B2, V'B3 is connected, by its output, to the low pressure return circuit RBP via an upstream pressure regulation valve actuated by a corresponding rigid link L ' i, L'2, L'3 by means of a lever LV1, LV2, LV3 articulated on the fixed structure of the bench so as to maintain substantially constant the pressure ratio of the two jacks by causing: - a reduction in the flow output of the low pressure cylinder V'B1, V'B2, V'B3 in response to a decrease in the pressure in the low pressure cylinder V'Bl, V'B2, V'B3 relative to the pressure of the high pressure cylinder

V'H1, V'H2, V'H3,

  an increase in the output flow rate of the low pressure cylinder V'B1, V'B2, V'B3 in the case of an increase in the pressure of the low pressure cylinder V'B1, V'B2, V'B3 relative to the high pressure cylinder pressure

V'H1, V'H2, V'H3.

  This regulation, which takes place here upstream of the valve RD1, RD2, RD3, also has the effect of maintaining

- 7 - 2722841

  the low pressure cylinder V'B1, V'B2, V'B3 at one level

substantially constant.

  Of course, the lever LV1, LV2, LV3 could be replaced by any suitable link or servo which could be mechanical, electromechanical,

  electric, pneumatic or hydraulic.

  As previously mentioned, the ratio between the surfaces of the low pressure pistons V'B1, V'B2, V'B3 and the surfaces of the high pressure pistons V'H1, V'H2, V'H3 of the self-pressurized tanks of the distribution facility is much higher than the corresponding area ratio of self-pressurized tanks of

circuits to be tested.

  In this case, the low pressure cylinder VB1, VB2, VB3 of the self-pressurized tank of the unit under test is

  has a bottom stop. As a result, the auto tank

  The pressurized tank of the unit under test is therefore neutralized, while the corresponding pressurized tank of the distribution installation becomes preponderant. By way of example, the surface area ratio of the cylinders of the circuit to be tested could be 300/6 = 50 and the surface area ratio of the corresponding cylinders of the distribution installation could be 300/3 = 100, i.e. - say equal

  double that of the cylinders of the circuit to be tested.

  An advantage of the solution described above is that it provides in each circuit a self-pressurized tank which can, at any time, absorb the pressure peaks (positive or negative) caused

  by rapid flow changes in the circuits.

- 8 - 2722841

Claims (7)

Claims   1. Hydraulic fluid distribution installation usable for testing or checking hydraulic circuits (B1, B2, B3) including self-pressurized hydraulic tanks   of the type comprising at least two cylinders (VH1, VH2, VH3 -   VB1, VB2, VB3) respectively high and low pressure, the pistons of which are connected to each other by a rigid connection (L1, L2, L3), said installation comprising an auxiliary circuit for producing pressurized hydraulic fluid ( G) whose high pressure intake (DHP) and low pressure return (RBP) conduits are connected to one or more pairs of connectors (CD1, CD2 - C'D1, C'D2 - C "D1, C" D2 ) by means of respective connection circuits, each pair of connectors (CD1, CD2 - C'D1, C'D2 - C "D1, C" D2) can be connected to a circuit to be tested of the above type, characterized in that each connection circuit includes an auxiliary self-pressurized reservoir comprising two respective auxiliary cylinders, namely: a high pressure cylinder (V'H1, V'H2, V'H3) connected to the high pressure intake duct (DHP) of the auxiliary circuit and a low pressure cylinder (V'B1, V'B2, V'B3) connected to the low pressure return circuit (RBP) of said cir auxiliary cooked, the pistons of the two auxiliary cylinders (V'H1, V'Bl - V'H2, V'B2 - V'H3, V'B3) of the same auxiliary tank being connected to each other by a rigid connection (L'i, L'2, L'3).   2. Installation according to claim 1, characterized in that the pistons of the two cylinders (V'H1,   V'B1 - V'H2, V'B2 - V'H3, V'B3) self-contained containers   pressurized tanks have a different surface ratio than that of the cylinders (VH1, VB1 - VH2, VB2 - VH3, VB3) constituting the self-pressurized tanks of the circuits under test. - 9 - 2722841   3. Installation according to claim 2, characterized in that the surface ratio of the auxiliary tanks is greater than that of the tanks of the circuits under test, so that, in the latter, the piston of the high pressure cylinder (VH1, VH2 , VH3) is held in high stop, while the piston of the low pressure cylinder (VB1, VB2, VB3) is in support in bottom stop.   4. Installation according to one of claims   previous, characterized in that the flow rate of hydraulic fluid delivered at the outlet of the low pressure cylinder (V'B1, V'B2, V'B3) of each auxiliary self-pressurized tank is regulated as a function of the position of the member link   (L'i, L'2, L'3) connecting the two pistons.   5. Installation according to claim 4, characterized in that the above flow control is designed so as to maintain a substantially constant level inside the low pressure cylinder (V'B1, V'B2, V'B3).   6. Installation according to one of claims   4 and 5, characterized in that the above regulation is ensured by means of a pressure regulation valve (RD1, RD2, RD3) placed at the outlet of the low pressure cylinders (V'B1, V'B2, V'B3) auxiliary self-pressurized tanks and which is actuated by means of an appropriate connection (LV1, LV2, LV3) from a corresponding rigid connection (L'i, L'2, L'3).   7. Installation according to claim 6, characterized in that the above connection is of mechanical, electromechanical, electrical, pneumatic nature. and / or hydraulic.