EP1039146A1 - 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 unlockable filling valve in the preamble of Claim 1 specified type.

In the filling valve known from prior use in practice (Fig. 4), the hydraulic unlocking of the counter stop connected to the shaft metallic hard on the stationary stop when the valve element is in the full open position reached. The area of action of the unlocking piston corresponds approximately a quarter of the cross-sectional area of the valve seat of the filling valve. The unlocking piston opposite to the opening stroke of the filling valve Return spring is relatively strong. As for the opening stroke of 50 mm, for example or more than a second is available, the valve element before Ejecting the pressure medium may be held at the valve seat by residual pressure and the mass of the valve element with its stem, the nut and the unlocking piston is considerable when being hit with a relatively high release pressure inside considerable energy was consumed in a short time. A similarly strong service can also occur during filling. Despite constructive protective measures, for example an expansion section in the shaft, occur in the shaft or in the connection area loads between the nut and the shaft that lead to breakage can, which requires expensive repairs and downtimes of the hydraulic press. The greater the valve seat diameter, the greater the risk it is crucial for the quick filling or emptying of the press cylinder.

The invention has for its object a filling valve of the type mentioned to create, in which the risk of damage in the The shaft or connection area of the nut with the shaft is minimized.

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

The impact damping device effective between the counter-stop and the stop leads to a "softer" serve, so that the serve energy is consumed more time is available and the load in the shaft or connection area between the mother and the shaft is reduced. This is great Valve seat diameter and advantageous when filling or pushing out.

The impact damping device is useful only within an excess stroke of the shaft effective. It is important that the valve element is so reaches the full open position as quickly as possible to achieve the maximum flow cross-section to clear the pressure medium as quickly as possible.

The impact damping device should not influence the adjustment of the valve element have in the closed position, so that a relatively low restoring force on Shaft is sufficient to the valve element after filling or pushing out into the To adjust the closed position.

Since the interior of the adjustment device is usually filled with pressure medium, offers a hydraulic impact damping device, depending on the stroke of the Shaft comes into effect.

Alternatively, a mechanical impact damping device can be used, the one has elastically deformable damping element. However, combinations are also possible from a hydraulic and a mechanical impact damping device.

The mother who forms the counter-stop no longer comes directly to the stop to attack, but indirectly via the impact damping device to at least one Consume part of the impact energy.

Furthermore, for damping by the displacement projection pressure medium from the Immersion recess pushed out over a narrow cross section. The suction check valve ensures that when the shaft is moved in the closing direction, the impact damping device does not brake. By dimensioning the immersion recess and / or the throttle cross-section for displacing the pressure medium, the Set the damping effect or characteristic.

There are only minor structural modifications compared to known construction principles necessary to accommodate the damping element. Will be expedient the damping element is positioned on an intermediate ring which is displaceable on the shaft, that does not follow the stroke movement of the shaft and the damping element in one Holds position that is favorable for damping.

In terms of construction, at least one O-ring positioned in an annular groove is used, which protrudes in the stroke direction over the ring groove and is deformed when it is impacted. It several O-rings could be connected in parallel, the same distance or different protrude far or have different hardness. Other ring-shaped ones could also be used Damping elements with non-circular cross sections can be used. It is also conceivable the use of at least one spring or more in the circumferential direction around the Distributed spring shaft.

The suction spring required to adjust the valve element to the closed position is also used to position the intermediate ring in a standby position, and prestress the damping element if necessary. This ensures that the intermediate ring does not follow the stroke movements of the shaft.

The centering flange ensures that the intermediate ring shifted 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 element. However, it is conceivable to use a similar one for the closing movement Impact damping device to be provided, 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.

Embodiments of the subject matter of the invention and a known embodiment of a filling valve are described with reference to the drawings. Show it:

Fig. 1

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

Fig. 2

2 shows an enlarged detail from FIG. 1,

Fig. 3

an enlarged section of another embodiment,

Figure 3A

an enlarged section of a further embodiment, and

Fig. 4

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

4, a hydraulically unlockable filling valve F is a known one and embodiment used for years for high performance presses explained.

The filling valve F in Fig. 4 has a disk-shaped solid housing 1 in which between a filling chamber K and a working chamber A, an annular valve seat P is shaped. A valve element V works with the valve seat P in the manner of a seat valve together, the one pointing upwards from a disk-shaped base body, has central shaft 4. Working chamber A does not communicate with you Shown cylinder space of a press piston (not shown), which consists of a Basic position near the filling valve F, e.g. towards the shaft 4, towards a press position is movable. The filling chamber K is limited by a filling chamber wall W, which extends up to a shaft passage 3 and approximately parallel runs to the top of the valve element V. Is part of the filling chamber wall W. an end wall 2 of an adjusting device E integrated into the housing 1, in which a Unlocking drive for the valve element V is provided. The adjustment device E is supported in the housing 1 on external webs T extending between which several beginning at the top of the housing 1 and in the Füllkammerwandung W opening kidney-shaped passages D are formed. In a Housing 5 placed on top protrudes shaft 4 of valve element V. In housing 5 is an unlocking piston 6 with seals 7 slidably guided by a a supporting web T extending unlocking channel 8 is hydraulically applied to the Valve element V from the closed position shown in the fully open position, not shown to move down. The unlocking piston 6 is 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 screwed to the shaft 4 and by a fuse 11 is secured. The nut 10 is in the closing direction by a weak suction spring 12 of the valve element V loaded. On the nut 10 is a counter stop R provided, which is aligned with a stationary stop S of the adjusting device E. is.

When the press piston, not shown, moves from its basic position is the valve element V from the closed position shown in the full open position moves, in which the nut 10 hits the stop S with its counter stop R. Pressure medium flows through the passages D, the filling chamber K and the valve seat S. along the top of the valve element V into the working chamber A and to the press piston. As soon as the press piston reaches the desired position and between A large pressure equalization took place in the passages D and the working chamber has, the valve element V by the suction spring 12 in the closed position adjusted. Then a press cycle is carried out by means not shown is controlled, the filling valve F remains in its closed position. Around the plunger in the basic position, if necessary after a pressure reduction Via a discharge 20, the unlocking piston 6 is hydraulically actuated in order to the valve element V via the nut 10 and against the forces of the springs 9, 23 in the Move open position. The pressure medium from the press cylinder is through the Valve seat S, the filling chamber K and the passages D pushed out. After that the unlocking piston 6 is depressurized and reset by the return spring 9. The Suction spring 23 then leads the valve element back into the closed position.

When the open position of the valve element V is reached, there is a hard Impact of the counter stop R on the stationary stop S. This means considerable Loads for the supporting webs P of the housing 1, the shaft 4 and the Connection area between the nut 10 and the shaft 4, which become the larger, the larger the diameter of the valve seat P. As for large high-performance presses and for the fastest possible press cycles the tendency towards bigger and bigger ones Valve seat diameters of the filling valve F, 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 functional reliability of the filling valve even with large valve seat diameters and work cycles with high frequency improve. An impact damping device G is provided which has a softer one Impact causes and the impact energy slowly consumes.

Components with the known filling valve (FIG. 4) are equivalent components 1 - 3A with the same reference numerals, so that a separate one Description may be unnecessary.

In the filling valve F according to the invention in FIGS. 1 and 2, the nut 10 with the Shank 4 connected via a threaded connection 13, which is secured by the fuse 11 is. In addition, an expansion taper is in the shaft 4 as a flanking measure 12 shaped. Between the counter stop R of the nut 10 and the stationary one Stop S of the adjusting device E is the impact damping device G. The shaft 4 is surrounded by an intermediate ring 14, which is on the shaft 4 is displaceable and contains an elastically deformable damping element 15 which for Impact damping works together 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 a radial Game. The intermediate ring 14 engages with a centering flange 17 over a circumferential one Shoulder 18 of the stop S to the shaft 4 from braking frictional forces keep clear. In an underside 29 of the intermediate ring 14 there is an annular groove 19 molded in which the damping element 15 is positioned. The damping element 15 is circular, e.g. an O-ring and projects over the bottom 29. The target stroke of the Shaft 4 until the full opening position is reached is X. The length of the nut 10 or the intermediate ring 14 is selected so that when largely relaxed Damping element 15 is a stroke oversize y, within which the impact damping device G comes into effect. The suction spring 23 is supported on a shoulder 21 of the intermediate ring 14 to close this in the standby position shown secure, and if necessary, slightly bias the damping element 15. The designated interior space 28 in the housing 5 is filled with pressure medium.

If the valve element is in the closed position shown in FIG. 2, right half, either when the unlocking piston 6 is acted upon or under suction Method of the press piston, not shown, or by pressurizing the passages D, moved to the full open position (left half), then meets in the open position the counter stop R on the intermediate ring 14, whereby this over the Excess stroke y is adjusted up to the stop on 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 and the intermediate ring 14 again in the standby position shown in Fig. 2, left side reset in which the valve element V is in the fully open position. Will then the valve element V moves 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. On the mother 10, a displacement projection 24 is provided, which defines the counter stop R. At the stationary stop S of the adjusting device E there is an immersion recess 22 formed for the displacement projection 24, which has a connection 25 with a Post-suction check valve 26 is connected to the chamber 28. The outside diameter of the displacement projection 24 is so on the inner diameter of the Immersion recess 22 matched that when the displacement protrusion penetrates 24 (Fig. 3, left half) pressure medium enclosed therein pushed out upwards and is throttled until the counter stop R meets the stop S. The Impact energy is at least partially consumed. The suction check valve 26 blocks in this flow direction. Subsequently, the valve element is back in the To move the closed position, then the displacement projection 24 from the immersion recess 22 pulled out, this movement by opening the suction check valve 26 is not braked.

It is conceivable to use the mechanical impact damping device G, for example of FIGS. 1, 2 to combine the hydraulic impact damping device G of FIG. 3, for example by inserting a damping element 15 into the stop S.

3A is a simple mechanical one 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 is designed as an O-ring Damping element 15 positioned, the stroke S over the stroke oversize y protrudes towards the counter stop R on the nut 10. The damping element 15 could, however, also be provided on the counter stop R. It is also conceivable at least one damping element each on the counter stop R and on the stop S. 15 to be provided.

1 to 3, the inlet area to the passages is relatively high. It it is possible to make the inlet area as shallow as that with the dashed line in FIG. 1 horizontal line is indicated.

Claims (11)

Hydraulically unlockable filling valve (F) for a hydraulic press, with a valve element (V) which is adjustable relative to a valve seat (P) and has a stem (4), the stem (4) of which is arranged in an adjusting device (E) and is counteracted by an unlocking drive Restoring force can be brought from a closed position into a predetermined open position and with a counter-stop (R) against a stationary stop (S), characterized in that an impact damping device (between the counter-stop (R) and the stop (S) in the adjusting device (E) G) is provided. Filling valve according to claim 1, characterized in that the stop (S) with respect to a desired stroke (X) of the shaft (4) between the closed and the open position is offset by a predetermined stroke oversize (y) beyond the open position, and that the impact damping device (G) is effective within the stroke oversize (y). Filling valve according to claim 1, characterized in that the impact damping device (G) is effective for the open position in the stroke direction of the shaft (4). Filling valve according to claim 1, characterized by a hydraulic impact damping device (G). Filling valve according to claim 1, characterized by a mechanical impact damping device (G) having at least one elastically deformable damping element (15). Filling valve according to claim 1, characterized in that a nut (10) arranged on the shaft (4) as the counter-stop (S) can be brought to bear on the stop (S) via the impact damping device (G). Filling valve according to at least one of the preceding claims, characterized in that an immersion recess (22) is arranged on the nut (10) or the stop (S) for a displacement projection (24) provided on the stop or the nut, and that between the immersion recess and a suction check valve (26) is arranged in a chamber (28) provided in the setting device (E) and filled with pressure medium. Filling valve according to at least one of the preceding claims, characterized in that an elastically deformable damping element (15) on the nut (10), on the stop (S) or on an intermediate ring (14) displaceable on the shaft (4) or on at least two of these Components is positioned. Filling valve according to claim 5, characterized in that the damping element (15) is annular, preferably as an O-ring inserted in an annular groove (19) with the stroke cover dimension (y) axially projecting. Filling valve according to claim 8, characterized in that the nut (10) in the direction of movement of the shaft (4) to the closed position is acted upon by a suction spring (23), and that the suction spring (23) is supported on the intermediate ring (14) and this in one securing the damping element (15) at the stop (S), preferably preloaded, in the ready position. Filling valve according to claim 8, characterized in that the intermediate ring (14) has a centering flange (17) which overlaps the stop (S).

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