Abstract:
A device to recuperate the energy produced during the recoiling of a weapon provided with a hydraulic fluid power circuit, wherein said device comprises an energy recuperating cylinder activated by the recoil of said weapon, a double-acting cylinder comprising two chambers separated by a piston, a first chamber of said cylinder being connected to said hydraulic power circuit of said weapon, said piston of said cylinder pushing said hydraulic fluid in said circuit into a storage accumulator when said weapon recoils. The energy recuperating cylinder comprises a second chamber connected to a recoil mechanism that ensures pressurising of said mechanism.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The technical scope of the invention is that of braking systems for an element in motion, for example a weapon during the recoil caused by firing a projectile, and which allow the energy thus developed to be recuperated. 
     2. Description of Related Art 
     Such devices are known and reference may be made to patent EP-0403452, which describes a device allowing the stored energy to be used to close the breach of a weapon. The device described only allows the energy to be used for a single type of to and fro movement such as, for example, that of the opening/closing of the breech, or else the ejection of thee stub. Generally speaking, the devices proposed do not allow the recuperated energy to be stored for possible use to other ends. 
     Moreover, known energy recuperators do not allow several networks to be powered. 
     The powering of a hydraulic network often requires a hydraulic generator of the engine and pump type whose bulk and mass are problematic and make them difficult to integrate into the frame of the weapon. 
     SUMMARY OF THE INVENTION 
     The aim of the invention is to propose an energy recuperation device that overcomes these drawbacks whilst allowing part of the recoil energy of the weapon to be recuperated and rendered according to the user&#39;s needs. 
     The invention thus relates to a device to recuperate the energy produced during the recoiling of a weapon, wherein it comprises an energy recuperating cylinder activated by the recoil of the weapon, a double-acting cylinder comprising two chambers separated by a piston, a first chamber of the cylinder being connected to a hydraulic power circuit of the weapon, the piston of said cylinder pushing the hydraulic fluid in this circuit into a storage accumulator when the weapon recoils. 
     According to one characteristic of the invention, the energy recuperating cylinder comprises a second chamber connected to a recoil mechanism that ensures its pressurising. 
     According to another characteristic of the invention, the recuperating cylinder incorporates a rod integral with the piston, such rod pushed by the weapon during its counter recoil. 
     According to another characteristic of the invention, the energy recuperating cylinder is connected to the weapon&#39;s hydraulic power circuit by means of main piping divided into at least two secondary pipings provided with first and second valves allowing the passage of a fluid in one direction only, one secondary piping connecting the main piping to the storage accumulator and another secondary piping connecting the main piping to a supercharging accumulator. 
     According to another characteristic of the invention, the first valve is placed between the supercharging accumulator and the main piping, and the second valve is placed between the main piping and the storage accumulator, the first valve being closed and the second valve open when the weapon recoils. 
     The storage accumulator may supply the weapon&#39;s hydraulic network with pressurised fluid via service piping. 
     According to a variant embodiment of the invention, the second chamber of the recuperating cylinder is connected to the nitrogen chanter of the recoil mechanism. 
     According to another variant embodiment of the invention, the second chamber of the recuperating cylinder is connected to the recoil mechanism via an oil circuit delimited on the nitrogen chamber side of the recoil mechanism by a free piston which separates the nitrogen and the oil circuit. 
     According to another variant embodiment of the invention, the second chamber of the recuperating cylinder is connected to the oil chamber of the recoil mechanism. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other characteristics, particulars and advantages of the invention will become more apparent from the additional description given hereafter by way of illustration and in reference to the appended drawings, in which: 
         FIG. 1  schematically illustrates the device according to the invention in its static phase, 
         FIG. 2  schematically illustrates the device according to the invention in its recoil phase, that is, in its energy accumulation phase, 
         FIG. 3  schematically illustrates the device according to the invention in the counter recoil phase, that is, in the supercharging phase of the energy recuperating cylinder, 
         FIG. 4  schematically illustrates a first variant embodiment of the invention, and 
         FIG. 5  schematically illustrates a second variant embodiment of the device according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The upper part of  FIG. 1  shows a weapon  1  whose recoil mass  1   a  is partially schematised. Each time the weapon is fired, and in a known manner, the weapon  1  performs a to and fro motion following arrow F 1 . This weapon  1  is attached to a recoil mechanism  20  comprising a first cylinder  9  whose rod  21  is integral with the recoiling mass of the weapon and a nitrogen chamber  10 . The rod  21  is integral with a piston  32  sliding in the cylinder  9  and delimiting chambers  8  and  23 . The nitrogen chamber  10  is limited by a free piston  7  that is also subjected to the action of a fluid in the cylinder  9  by means of a chamber  22 . When the weapon recoils after firing a round, the weapon moves rapidly in the direction of arrow F 2 . In a known manner, the fluid in cylinder  9  passes through a calibrated opening and supplies chamber  22  thereby causing the nitrogen contained in chamber  10  to be compressed by means of the free piston  7 . The recoil movement of the weapon is, moreover, rapidly braked thanks to a recoil brake (not shown) coupled with the recoil mechanism  20 . 
     The nitrogen compressed in chamber  10  exerts a pressure on piston  7 , which, after recoil, causes the counter recoil of the recoiling mass  1   a , and the return of the rod  21  to its starting position. 
     According to the invention, an energy recuperating device  2  is provided that is connected to the nitrogen chamber  10  and activated by the weapon&#39;s recoil. This device is shown in the lower part of  FIG. 1 . To this end, the device comprises an energy recuperating cylinder  3 , comprising a piston  24  sliding in the cylinder body  3  and integral with a rod  4  pressing at one end against the recoiling mass  1   a  of the weapon  1 . 
     This piston  24  delimits a first chamber  6  and a second chamber  5 . The second chamber  5  of the cylinder  3  communicates with the nitrogen chamber  10  and thus also contains nitrogen. The first chamber  6  communicates with a fluid accumulator assembly  25 . 
     The assembly  25  firstly comprises a supercharging accumulator  15  and secondly a storage accumulator  16 . The accumulator  15  may be supplied with oil by piping  36  bringing the oil back from the different actuators of the hydraulic circuit (not shown). The accumulator may also be supplied using a pump motor  18 . The supercharging accumulator  15  is a low pressure accumulator (pressure at around 3.10 5  Pa to 10 6  Pa). 
     The storage accumulator is in the form of a pressurised oil tank intended to supply one or several apparatus (not shown) by means of service piping  27 . 
     The storage accumulator  16  is a high pressure accumulator (pressure at around 1.5.10 7  Pa to 2.5.10 7  Pa). 
     The chamber  6  of the cylinder  3  communicates with the assembly  25  by main piping  19  that is divided into two branches  11  and  12  each provided with a non-return valve, respectively  13  and  14 . Valve  13  only allows the passage of compressed fluid from the supercharging accumulator  15  towards the cylinder  3 . Valve  14  only supplies the storage accumulator  16  with compressed fluid via a piston  3  (the low pressure of the supercharging accumulator  15  always being lower than the high pressure of the storage accumulator  16 ). 
     The compressed fluid may classically be oil. Each accumulator  15  or  16  will classically incorporate a gas chamber, not shown, isolated from the fluid by means of a membrane and allowing the accumulator to become pressurised. 
       FIG. 2  shows the device according to the invention during an intermediate step in the recoil phase of the weapon, that is, during the energy recuperation phase, the end position of the weapon not being shown since superfluous to understanding the operation. 
     The recoiling mass of the weapon  1  has recoiled a certain distance following arrow F 2  driving with it the rod  21  of the cylinder  9 . The recoil mechanism  20  fulfils its function and the fluid contained in chamber  23  is pushed back into chamber  22  thereby causing the nitrogen contained to chamber  10  to be compressed. The pressure of the nitrogen in chamber  5  increases concomitantly and pushes the piston  24  of the recuperators  3 , thereby pushing back the oil contained in the first chamber  6 . This pressurised oil is conducted by means of the valve  14 , into the high pressure storage accumulator  16 . Thus, part of the energy produced by the weapon&#39;s recoil has been recuperated. This energy is available in the accumulator  16  to be used at any time, for example by means of piping  27 . 
       FIG. 3  shows the device according to the invention during the counter recoil phase of the weapon. It is the pressure of the nitrogen contained in the chamber  10  which, as succinctly explained above, causes this counter recoil movement of the weapon. The recoiling mass of the weapon  1  therefore pushes the rod  4  of the cylinder  3  (and thus the piston  24 ) bringing it back into its starting position as shown in  FIG. 1 . This return movement of the piston  24  causes a depressurising of the oil in the main piping  19  resulting in the opening of valve  13  and the supercharging accumulator  15  ensures the first chamber  6  of the cylinder  3  is filled with oil. The valve  14  remains closed by the high pressure of the storage accumulator  16  which is greater than the pressure supplied by the supercharging accumulator  15 . 
       FIG. 4  illustrates a variant embodiment of the recuperator device according to the invention. 
     In this example, the second chamber  5  of the recuperating cylinder  3  is connected to the recoil mechanism  20  by means of an oil circuit comprising piping  29 . This oil circuit is delimited on the, nitrogen chamber  10  side of the recoil mechanism  20  by a second free piston  17  that isolates the nitrogen and the oil circuit. 
     The chamber  10  containing the nitrogen no longer communicates with the second chamber  5  of the recuperating cylinder  3 . 
     The piston  17  carries a rod  31  whose protrusion from the recoil mechanism  20  allows the oil replenishment level of the system to be visualised. The operating principle remains globally the same, the nitrogen pressure in this case being applied to the piston  24  of the recuperating cylinder  3  by means of another fluid. 
     This embodiment offers the advantage of being safer. Indeed, should the piping  29  rupture accidentally, there would be no leakage of nitrogen and the recoil mechanism  20  would remain operational. Firing would still be possible. 
       FIG. 5  shows another variant embodiment of the recuperation device according to the invention. 
     In this example, the second chamber  5  of the recuperating cylinder  3  is connected to the oil chamber  22  of the recoil mechanism  20  of the weapon by means of piping  30 . Thus, when the weapon  1  recoils, the oil is pushed from chamber  23  to chamber  22  and thus towards the second chamber  5  of the recuperating cylinder  3 . During the counter recoil phase, the nitrogen pressure in the chamber  10  causes the counter recoiling of the weapon&#39;s recoiling mass. The recoiling mass pushes back the rod  4  and the resulting depressurising of the oil in the main piping  19  causes the circuit to be resupplied with oil by the supercharging accumulator  15 . Other variants are naturally possible without departing from the scope of the invention. 
     In all the above Figures, the hydraulic circuit is shown schematically. The relative dimensions and proportions of the different components are thus not respected. 
     Naturally, this circuit also comprises the usual control and safety organs such as manometers and pressure control valves.