EP1039146B1 - Pilot operated filling valve - Google Patents

Abstract

The filling valve (F) has a valve element (V) with a shaft (4), adjustable relative to a valve seat (P). The shaft is in a setting device (E). It can be moved by the unlocking drive against a return force from a closed position to a preset open position, bringing a counter-stop (R) on the shaft against a fixed stop (S). An impact damping device (G) is fitted in the setting device between the counter-stop and the stop.

Description

The invention relates to a hydraulically releasable filling valve in the preamble of Claim 1 specified type.

In the known by prior use in practice filling valve (Fig. 4), suggests hydraulic unlocking the counter-stop connected to the shaft metallic hard on the stationary stop when the valve element is in the fully open position arrives. The loading surface of the release piston corresponds approximately a quarter of the cross-sectional area of the valve seat of the filling valve. The the release piston opposite to the opening stroke of the filling valve acted upon Return spring is relatively strong. As for the opening stroke of, for example, 50 mm or more than a second is available, the valve element before the Pushing out the pressure medium optionally held by residual pressure on the valve seat is, and the mass of the valve element with its shaft, the nut and the release piston is considerable, is at impact with relatively high Entsperrdruck within consumed considerable energy in a short time. A similarly strong serve can also occur during filling. Despite constructive protective measures, for example a Dehnabschnitt in the shaft, occur in the shaft or in the connection area between the nut and the shaft loads that lead to a break can, which requires expensive repairs and downtime of the hydraulic press. This danger is greater, the larger the valve seat diameter, in turn It is crucial for the fast filling or emptying of the press cylinder.

In one known from DE 40 35 338 A inlet valve of an internal combustion engine a hydraulic damping device is provided which is in the final phase of the Valvesschließhubes comes into effect and the impact of the valve disc on the Valve seat dampens. On the valve stem a cup-shaped damping body is displaceable guided, which limits a pressure chamber with a shoulder of the shaft. The damping body serves at the same time as an opponent of the valve closing spring, which in a with Pressure medium filled pressure chamber is arranged. The damping device is dependent from the speed of the motor or the valve closing frequency with respect to the damping stroke adjustable.

In a known from US-A-4,872,638, slow-acting pneumatic valve is a dampening piston is provided on a shaft connected to the valve element, which is sealed displaceable in a fluid-filled chamber and throttle passages contains. Similar to a shock absorber, the fluid between the two Piston sides shifted back and forth, when the damping piston with the valve element emotional. As a result, the movement of the valve element is delayed

In one known from US-A-4 531 542, hydraulic pressure control valve is on a arranged a damping piston with the valve closing element coupled shank, which is reciprocable in a chamber filled with pressure medium and forth. in the Shank are communicating with each other on both sides of the damping piston Throttle openings provided so that the pressure fluid during movements of the damping piston moved back and forth between the sides of the piston and thereby throttled is to dampen the movements of the Ventilschtießelementes.

Further prior art is contained in EP-A 663 270, FR-A-28 7434, GB-A-1 209 088 and DE-U-79 31 561.

The invention is based on the object, a filling valve of the type mentioned to create, especially at rapid filling cycles the risk of damage in the Shank or connecting region of the nut is minimized with the shaft.

The object is achieved according to the invention with the features of claim 1 solved.

The effective between the counter stop and the stop impact damping device leads to a "softer" impact, allowing to consume the impact energy more time is available and the load in the shaft or connecting area between the nut and the shaft is reduced. This is for big Valve seat diameter and when filling or ejection advantageous. The impact damping device should not affect the adjustment of the valve element in the Closed position, so that a relatively small restoring force on the shaft is sufficient around the valve element after filling or pushing out into the closed position to adjust. It comes the counter-attacking mother not directly on Attack to attack, but indirectly via the impact damping device, at least to consume a portion of the impact energy. There are only minor structural Modifications to known design principles necessary to the Accommodate damping element. Appropriately, the damping element is at a on the shank displaceable intermediate ring positioned, the lifting movement of the Shaft does not join and holds the damping element in a position that for damping is cheap.

Suitably, the impact steam device is exclusively within a Hubübermaßes of the shaft. It is important that the valve element is so reaches full open position as quickly as possible to the maximum flow area to clear the pressure medium as quickly as possible.

Since the interior of the adjusting device is usually filled with pressure medium offers a combination of a hydraulic and a mechanical impact damping device at, wherein the hydraulic impact damping device also depending on the stroke of the shaft comes into effect. This is for steaming through the positive displacement projection pressure medium from the immersion well over a cramped Section pushed out. The Nachsaugrückschlagventil ensures that when Stroke of the shaft in the closing direction does not brake the impact damping device. By dimensioning the immersion recess and / or the throttle cross section for Displacement of the pressure medium can be the damping effect or damping characteristic to adjust.

Structurally simple at least one positioned in an annular O-ring is used, which projects in the stroke direction over the annular groove and is deformed during impact. It Several O-rings could be connected in parallel, the same or different protrude far or have different hardness. Furthermore, other, annular Damping elements are used with non-circular cross-sections. It is also possible the use of at least one spring or more in the circumferential direction around the Shank of distributed springs.

The Nachsaugfeder required to adjust the valve element to the closed position is used to position the intermediate ring in a ready position and optionally to bias the damping element. This will achieve that the intermediate ring does not join the strokes of the shaft.

Due to the centering flange ensures that the impact of the intermediate ring displaced in a predetermined manner and no harmful forces on the shaft exercises that could hinder its movement.

The impact damping device is particularly useful for the opening stroke of the Valve member. However, it is conceivable, even for the closing movement a similar To provide impact damping device, although the impact energy in the closing direction is less than in the opening direction.

Fig. 1

eine erste Ausführungsform eines hydraulisch entsperrbaren Füllventils gemäß der Erfindung, in der linken Hälfte in der Offenstellung, in der rechten Hälfte hingegen in der Schließstellung, jeweils in einem Axialschnitt,

Fig. 2

einen vergrößerten Ausschnitt aus Fig. 1,

Fig. 3

einen vergrößerten Ausschnitt einer anderen Ausführungsform,

Fig. 3A

einen vergrößerten Ausschnitt einer weiteren Ausführungsform, und

Fig. 4

einen Axialschnitt eines bekannten Füllventils (Stand der Technik) in der Schließstellung.

With reference to the drawings, embodiments of the subject invention will be described, and a known embodiment of a filling valve. Show it:

Fig. 1

a first embodiment of a hydraulically releasable filling valve according to the invention, in the left half in the open position, in the right half, however, in the closed position, each in an axial section,

Fig. 2

an enlarged detail of Fig. 1,

Fig. 3

an enlarged detail of another embodiment,

Fig. 3A

an enlarged section of another embodiment, and

Fig. 4

an axial section of a known filling valve (prior art) in the closed position.

First, with reference to FIG. 4, a hydraulically releasable filling valve F of a known and embodiment used in practice for high performance presses for years explained.

The filling valve F in Fig. 4 has a disk-shaped solid housing 1, in the between a filling chamber K and a working chamber A an annular valve seat P is shaped. With the valve seat P, a valve element V operates in the manner of a seat valve together, which points upwards from a disc-shaped main body, has central shaft 4. The working chamber A does not communicate with one shown cylinder space of a press piston (not shown), which consists of a Basic position near the filling valve F, e.g. in the direction of the shaft 4, towards a pressing position is movable. The filling chamber K is bounded by a filling chamber wall W, which extends up to a shaft passage 3 and approximately parallel extends to the top of the valve element V. Part of the Füllkammerwandung W is an end wall 2 of an integrated into the housing 1 adjusting E, in a Entsperrantrieb for the valve element V is provided. The adjustment E is in the housing 1 supported on from outside to inside supporting webs T, between which several beginning at the top of the housing 1 and in the Füllkammerwandung W forming kidney-shaped passages D are formed. In one the upper part of the housing 5 projects the shaft 4 of the valve element V. In the housing. 5 is a Entsperrkolben 6 slidably guided with seals 7, which has a through a support bar T extending Entsperrkanal 8 is applied hydraulically to the Valve element V from the closed position shown in the fully open position, not shown to move down. The release piston 6 is replaced by a strong return spring 9 loaded, which is supported in the adjusting device E. On the shaft 4 sits a nut 10 which is bolted to the shaft 4 and a fuse 11th is secured. The nut 10 is connected by a weak Nachsaugfeder 12 in the closing direction the valve element V charged. At the nut 10 is a counter-attack R provided, which is aligned with a stationary stop S of the adjusting device E. is.

During a movement of the press piston, not shown, from its basic position the valve element V from the closed position shown in the fully open position moves, in which the nut 10 meets with its counter-stop R on the stop S. Pressure fluid flows through the passages D, the filling chamber K and the valve seat S. along the top of the valve element V in the working chamber A and the press piston. As soon as the press piston reaches the desired position and between the passages D and the working chamber a substantial pressure equalization took place has, the valve element V by the Nachsaugfeder 12 in the closed position adjusted. Then, a press tact is performed by means not shown is controlled, wherein the filling valve F remains in its closed position. To the plunger reset to the normal position, if necessary after a pressure reduction via a discharge 20, the Entsperrkolben 6 hydraulically applied to the valve element V via the nut 10 and against the forces of the springs 9, 23 in the To move open position. The pressure medium from the press cylinder is through the Valve seat S, the filling chamber K and the passages D ejected. After that will the Entsperrkolben 6 depressurized and reset by the return spring 9. The Nachsaugfeder 23 then performs the valve element back into the closed position.

Upon reaching the open position of the valve element V, it comes to a hard Impact of the counter-attack R on the stationary stop S. This means considerable loads for the support webs P of the housing 1, the shaft 4 and the Connection area between the nut 10 and the shaft 4, which become larger, the larger the diameter of the valve seat P is. As for large high-performance presses and for the fastest possible press cycles the tendency to ever larger ValveiUdurchmessem the filling valve F is present, this load means an acute Danger to the functional safety of the filling valve.

In the filling valve according to the invention according to FIGS. 1, 2, 3 and 3A, this danger removed from the hard impact to the reliability of the filling valve also with large valve seat diameter and high-frequency work cycles improve. It is provided an impact damping device G, which is a softer Serve and consumes the impact energy slowly.

With components of the known filling valve (Fig. 4) are equivalent components in Figs. 1 - 3A provided with the same reference numerals, so that this is a separate Description should be dispensable.

When filling valve F according to the invention in Figs. 1 and 2, the nut 10 with the Shaft 4 connected via a threaded connection 13, which is secured by the fuse 11 is. In addition, in the shaft 4 as an accompanying measure a Dehnverjüngung 12 shaped. Between the counter stop R of the nut 10 and the stationary one Stop S of the adjustment E is the impact damping device G classified The shaft 4 is surrounded by an intermediate ring 14, which on the shaft 4th is displaceable and contains an elastically deformable damping element 15, the Impact damping cooperates with the stationary stop S (mechanical Impact damping device G).

In Fig. 2, an inner bore 16 of the intermediate ring 14 surrounds the shaft 4 with radial Game. The intermediate ring 14 engages with a centering flange 17 via a circumferential Shoulder 18 of the stop S to the shaft 4 of braking frictional forces kept clear. In an underside 29 of the intermediate ring 14 is an annular groove 19th molded, in which the damping element 15 is positioned. The damping element 15 is annular, e.g. an O-ring and jumps over the bottom 29 before. The nominal stroke of the Shaft 4 until reaching the full open position is X. The length of the nut 10 and the intermediate ring 14 is selected so that at largely relaxed Damping element 15 is a stroke oversize y, within which the impact damping device G comes into effect. The Nachsaugfeder 23 is based on a shoulder 21 of the intermediate ring 14 from to this in the standby position shown secure, and possibly slightly bias the damping element 15. Of the 28 designated interior in the housing 5 is filled with pressure medium.

If the valve element from the closed position shown in Fig. 2, right half, either by applying the Entsperrkolbens 6 or under the suction at Method of the press piston, not shown, or by pressurization via the passages D, moves to the full open position (left half), then hits in the fenstellung the counter-attack R on the intermediate ring 14, whereby this over the Stroke excess y is adjusted as far as possible on the stop S. The damping element 15 is elastically deformed to dampen the impact. Once the impact energy is consumed, the damping element 15 can deform back and the intermediate ring 14 back into the ready position shown in Fig. 2, left side reset, in which the valve element V is in the full open position. Will be afterwards the valve element V is moved back into the closed position, then remains the intermediate ring 14 in the standby position shown.

In Fig. 3, a hydraulic impact damping device G is provided. At the mother 10, a positive displacement projection 24 is provided which defines the counter stop R. When stationary stop S of the adjustment E is an immersion well 22 formed for the Verdrängervorsprung 24, which via a connection 25 with a Nachsaugrückschlagventil 26 is connected to the chamber 28. The outer diameter the Verdrängervorsprungs 24 is so on the inner diameter of the Immersion well 22 tuned that when penetrating the Verdrängervorsprungs 24 (Fig. 3, left half) contained therein pressure medium pushed upwards and throttled until the counter-attack R meets the stop S. The Impact energy is at least partially consumed. The suction check valve 26 locks in this flow direction. Is below the valve element back into the To move closed position, then the Verdrängervorsprung 24 from the immersion recess 22 pulled out, this movement by opening the Nachsaugrückschlagventils 26 is not braked.

It is conceivable, the mechanical impact damping device G about the Fig. 1, 2 with the hydraulic impact damping device G of FIG. 3, for example by inserting a damping element 15 in the stop S.

In the embodiment of the filling valve of Fig. 3A is a simple mechanical Impact damping device G without the intermediate ring 14 shown in FIGS. 1, 2 intended. In the stop S, the annular groove 19 is formed, which designed as an O-ring Damping element 15 positioned over the stop S by the stroke oversize y protrudes towards the counter-stop R on the nut 10. The damping element 15 However, could also be provided at the counter stop R. It is also conceivable both at the counter stop R and at the stop S in each case at least one damping element 15 to provide.

In Fig. 1 to 3, the inlet region is formed relatively high to the passages. It is possible to form the inlet area as shallow as in Fig. 1 with the dashed horizontal line is indicated.

Claims (7)

1. Hydraulically releasable filling valve (F) for a hydraulic press, with a valve element (V) which is adjustable in relation to a valve seat (P) and has a shank (4) and the shank (4) of which is arranged in an adjusting device (E) and can be brought by means of a releasing drive, counter to a return force, out of a closing position into a predetermined open position and can be brought, with a counterstop (R) formed by a nut (10) arranged on the shank (4), against a stationary stop (S), characterized in that the adjusting device (E) has provided in it, between the nut (10) and the stop (S), a mechanical impact-damping device (G) having at least one elastically deformable damping element (15), and in that the damping element (15) is positioned on the nut (10) and/or on the stop (S) and/or on an intermediate ring (14) displaceable on the shank (4).
2. Filling valve according to Claim 1, characterized in that the stop (S) is offset by the amount of a predetermined stroke overdimension (y) beyond the open position with respect to a desired stroke (X) of the shank (4) between the closing position and the open position, and in that the impact-damping device (G) is effective within the stroke overdimension (y).
3. Filling valve according to Claim 1, characterized in that the impact-damping device (G) is effective in the stroke direction of the shank (4) towards the open position.
4. Filling valve according to Claims 1 and 2, characterized in that the damping element (5) is of annular design, preferably as an O-ring inserted into an annular groove (19) and projecting axially by the stroke overdimension (y).
5. Filling valve according to Claim 1, characterized in that the nut (10) is acted upon in the direction of movement of the shank (4) towards the closing position by an aftersuction spring (23), and in that the aftersuction spring (23) is supported on the intermediate ring (14) and secures the latter in a preferably prestressed position of readiness positioning the damping element (15) at the stop (S).
6. Filling valve according to Claim 5, characterized in that the intermediate ring (14) has a centring flange (17) engaging over the stop (S).
7. Filling valve according to at least one of the preceding claims, characterized in that the mechanical impact-damping device (G) is combined with a hydraulic impact-damping device which on the nut (10) or the stop (S) has a penetration depression (22) for a displacer projection (24) provided on the stop or the nut respectively, and in that an aftersuction non-return valve (26) is arranged between the penetration depression (22) and a chamber (28) provided in the adjusting device (E) and filled with pressure medium.

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