FR2659412A1 - Non-return valve device for hydraulic circuits - Google Patents

Abstract

Non-return valve device (1) for hydraulic circuits, including a tubular body (2) containing a valve (3) pushed into abutment on a seat (4) of the body by a spring (5) bearing on a sleeve (7) fixed inside the body, the spring (5) being interposed between the body (2) and the sleeve (7), characterised in that the body (2) and the sleeve (7) are welded together by electron bombardment. This fastening means renders the sleeve/body connection undismantleable and leaktight and therefore guarantees the operational reliability of the valve.

Description

 The subject of the present invention is a static non-return valve for hydraulic circuits, of the type comprising a tubular body containing a valve pushed in purpose on a seat of the body, by a spring bearing on an element fixed internally. to the body.

 F: n if the spring breaks, its debris is then entrained in the hydraulic circuit thus polluted, and can even hoist the pump.

 Polishing solve this problem, it has been proposed to force-fit a sleeve into the end of the body, the spring then being interposed, and trapped, between the latter and the body, bearing on a rim of the sleeve. The socket is fixed to the body by screwing or gluing.

However, it has been found that in the long run such a fastening has insufficient mechanical resistance and resistance, causing after a certain period of service a risk of separation of the sleeve from the body, and the interruption of the valve functioning
In addition, these techniques require the addition of additional parts and therefore complicate the structure of the device.

 The object of the invention is therefore to propose a solution to this problem.

According to the invention, the body and the socket are welded together by electronic bombardment
We obtain. thus a non-removable valve, the hydraulic circuit of which is protected against the consequences of a possible breakage of the spring, which is trapped between the sleeve and the body.

 The implementation of a fixing by welding is not obvious, a priori, because the body and the socket of this device are parts of small dimensions (body having a thickness of Imm for example), therefore difficult to weld. In addition, the usual welding techniques are not satisfactory, since they are too powerful for the size of the socket and of the body. Girls therefore cause a degradation of the mechanical and geometric characteristics of the valve by deformation of the metal of which the latter is made, causing a deterioration of the function.

 Only ultimately proved entirely satisfactory and adapts to the problem posed the technique of electron bombardment welding.

 The invention will now be described with reference to the single appended figure, which is a view in axial section and partial elevation of a nonlimiting embodiment of the valve device according to the invention.

 te non-return valve device 1 illustrated in the drawing is intended for a hydraulic circuit not shown1 for example controls of the control surfaces of an aircraft.

 It comprises a tubular body 2 containing a non-return valve 3 pushed into abutment on an annular seat 4 of the body 1 by a heicoïdaL spring 5 bearing on an annular flange 6 of a socket 7 fixed int.eriellement. body 1.

 The valve 3 has a belt 8 bearing on the seat 4, on either side of which are formed a conical head 9 and recesses 11, facilitating the passage of the hydraulic fluid when the valve 3 is moved away from the seat 4.

 The extremi.te of the spring 5 opposite the flange 6 bears on the periphery of the valve 3 between a flange 12 thereof and the wall of the body 1.

 The annular rim 6 is. engages in abutment against a complementary shoulder 13 of the body 1, and the spring 5 is. therefore trapped between the body 1 and the sleeve 7. On the side of the valve 3, the end 7a of the sleeve 7 is engaged inside the collar 12, which can thus slide around the sleeve 7 during the back and forth comes from the valve 3. An annular shoulder 14 is provided. in the central zone of the sleeve 7, and forms a stop stop for the flange 12 and the valve 13 in the open position of the latter, with correlative compression of the spring 5.

 The end 7b of the sleeve 7 adjoining the end 2a of the body 2 adjacent to the rim 13 is welded at this end 2a along a circular bead S produced by electronic bombardment, by means of an apparatus known per se and not shown. Thus the socket 7 and) e body 2 are secured by constituting a one-piece peak, practically non-removable. In operation of the non-return valve, the sleeve 7 cannot therefore separate from the body 2, which guarantees the operational safety of the valve.

 In the event of a rupture of the return spring 5, the latter remains trapped between the sleeve 7, the body 2 and the valve 3 by virtue of the fitting of the collar 12 and the inner end part 7a of the sleeve 7. this fact its debris cannot be entrained in the hydraulic circuit and pollute it.

 It will be noted that the attachment of the socket 7 to the body 2 by electronic bombardment also has the advantage of making this connection watertight.

Claims (2)

 1. Non-return valve device (1) for hydraulic circuits, comprising a tubular body (2) containing a valve (3) pushed into abutment on a seat (4) of the body by a spring (5) bearing on a bushing (7) fixed internally to the body, the spring (5) being interposed between the body (2) and the sleeve (7), characterized in that the body (2) and the sleeve (7) are welded together by electronic bombardment .  2. Device according to claim 1, characterized in that the sleeve (7) has an annular flange (6) bearing the spring (5) for returning the valve (3), and which is engaged in abutment against a shoulder (13) of the body, and the welding is carried out between the ends (2a, 7b) of the tube (7) and of the body (2) adjacent to said support flange (6) of the spring (5).