DE29905322U1 - Hydraulically unlockable 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

GRÜNEECKER,

VNfS ₁ LT SS*OZ Tt TAT'

LAW FIRM MAXIMILIANSTRASSE 58 D-80538 MUNICH GERMANY

Applicant:

HEILMEIER & WEINLEIN FABRIK F. OEL-HYDRAULIK GMBH & CO. KG STREITFELDSTRASSE 25 81673 MUNICH

LAWYERS

MUNICH

DR. HELMUT EICHMANN

GERHARD BARTH

OR. ULRICH BLUMENRÖDER, LL.M.

CHRISTA NIKLAS-FALTER

DR. MICHAEL SCHRAMM, DIPL-PHYS.

DR. MAXIMILIAN KINKELDEY. LLM.

OFCOUNSEL
PATENT ATTORNEYS

AUGUST GRÜNEECKER
DR. GUNTER BEZOLD
DR. WALTER LANGHOFF

DR. WILFRIED STOCKMAIR (-19961

PATENT ATTORNEYS

EUROPEAN PATENT ATTORNEYS

MUNICH

DR. HERMANN KINKELDEY

DR. KLAUS SCHUMANN

PETER H. JAKOB

WOLFHARD MEISTER

HANS HILGERS

DR. HENNING MEYER-PLATH

ANNE EHNOLD

THOMAS SCHUSTER

DR. KLARA G0LD8ACH

MARTIN AUFENANGER

GOTTFRIED KLITSCH

DR. HEIKE VOGELSANG-WENKE

REINHARD KNAUER

DIETMAR KUHL

DR. FRANZ-JOSEF ZIMMER

BETTINA K. REICHELT

DR. ANTON K. PFAU

DR. UDO WEIGELT

RAINER BERTRAM

JENS KOCH, MS (UofPA) MS (ENSPM)

COLOGNE

DR. MARTIN DROPMANN

YOUR REF.

OUR REF.

G 4065-25/Dr DATE

23.03.99

Hydraulically unlockable filling valve

MAXIMILIANSTRASSE 58 D-80538 MUNICH

TEL 089/21 23 50 FAX (Gr.3) 089 / 22 02 87, (Gr.4) 089 / 21 86 92 93 http://www.grunecker.de - e-mail: postmaster@grunecker.de KAISER-WILHELM-RING 13 D-50672 KÖLN

TEL 0221 /94 97 22 0 FAX (Gr.3) 0221/94 97 22 2

e-mail: dropmann@grunecker.de

DEUTSCHE BANK MUNICH NO. 17 51734 BLZ 700 700 10 SWIFT: DEUT DE MM

Hydraulically unlockable filling valve

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

In the case of such a filling valve, known from previous use in practice (Fig. 4), the counter-stop connected to the shaft strikes the stationary stop with a hard metallic impact during hydraulic unlocking as soon as the valve element reaches the fully open position. The area of the unlocking piston is approximately one quarter of the cross-sectional area of the valve seat of the filling valve. The return spring that acts on the unlocking piston in the return direction, i.e. opposite to the opening stroke of the filling valve, is relatively strong. Since less than a second is available for the opening stroke of, for example, 50 mm or more, the valve element may be held on the valve seat by residual pressure before the pressure medium is pushed out, and the mass of the valve element with its shaft, nut and unlocking piston is considerable, considerable energy must be consumed within a very short time when the unlocking pressure is relatively high. A similarly large impact energy can also occur during filling. Despite design measures, such as an expansion section in the shaft, stresses occur in the shaft or in the connection area between the nut and the shaft, which can lead to breakage, which then causes expensive repairs and downtime for the hydraulic press. This risk increases the larger the valve seat diameter is chosen, which is crucial for quickly filling or emptying the press cylinder.

The invention is based on the object of creating a filling valve of the type mentioned at the beginning in which the risk of damage to the shaft or the connection area of the nut with the shaft is eliminated, particularly during rapid filling cycles.

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

The impact damping device acting between the counter stop and the stop results in a "softer" impact, so that more time is available to absorb the impact energy and the load in the shaft or connection area
between the nut and the shaft is reduced. This is advantageous for large valve seat diameters and when filling or pushing out.

According to claim 2, it is expedient to allow the impact damping device to be effective only within a stroke oversize of the shaft. It is important that the valve element reaches the fully open position as quickly as possible,
to achieve the maximum flow area for the pressure medium as quickly as possible
possible to clear.

According to claim 3, the impact damping device has no influence on the adjustment of the valve element into the closed position, so that a relatively low restoring force on the shaft is sufficient to adjust the valve element into the closed position after filling or pushing out.

Since the interior of the adjustment device is usually filled with pressure medium,
According to claim 4, a hydraulic impact damping device is provided which comes into effect depending on the stroke of the shaft.

Alternatively, according to claim 5, a mechanical impact damping device can be used which has an elastically deformable damping element. However,
also combinations of a hydraulic and a mechanical impact damping device
possible.

According to claim 6, the nut forming the counter-stop no longer acts directly on the stop, but indirectly via the impact damping device in order to absorb at least part of the impact energy.

According to claim 7, the displacement projection pushes pressure medium out of the immersion recess over a narrow cross-section in order to dampen. The suction check valve ensures that no braking effect of the impact damping device occurs when the shaft is lifted in the closing direction. The damping effect or damping characteristics can be adjusted by dimensioning the immersion recess and/or the throttle cross-section for displacing the pressure medium.

According to claim 8, only minor structural modifications compared to known design principles are necessary to accommodate the damping element. It is particularly expedient to position the damping element on an intermediate ring that can be moved on the shaft, which does not follow the stroke of the shaft and holds the damping element in a position that is favorable for impact damping.

In a structurally simple manner, according to claim 9, at least one O-ring positioned in an annular groove is used, which protrudes beyond the annular groove in the stroke direction and is deformed upon impact. Several O-rings could be connected in parallel, which protrude the same or different distances or have different hardnesses. Furthermore, other ring-shaped damping elements with non-circular cross-sections could be used. The use of at least one spring or several springs distributed in the circumferential direction around the shaft is also conceivable.

According to claim 10, the suction spring required to adjust the valve element to the closed position is additionally used to position the intermediate ring in a ready position and, if necessary, to pre-tension the damping element. This also ensures that the intermediate ring does not follow the stroke movements of the shaft.

Finally, according to claim 11, the centering flange ensures that the intermediate ring is displaced in a predetermined manner upon impact and, above all,

does not exert any harmful forces on the shaft 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 provide a similar impact damping device for the closing movement, even though the impact energy in the closing direction is lower than in the opening direction.

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

Fig. 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 in the closed position, each in an axial section,

Fig. 2 shows an enlarged section of Fig. 1,

Fig. 3 shows an enlarged section of another embodiment,

Fig. 3A is an enlarged detail of another embodiment, and

Fig. 4 shows an axial section of a known filling valve in the closed position.

First, a hydraulically unlockable filling valve F of a known design that has been used for years in practice for high-performance presses is explained using Fig. 4.

The filling valve F in Fig. 4 has a disk-shaped solid housing 1 in which an annular valve seat P is formed between a filling chamber K and a working chamber A. A valve element V works together with the valve seat P in the manner of a seat valve, which has a disk-shaped base body pointing upwards.

the central shaft 4. The working chamber A communicates with a cylinder chamber (not shown) of a press piston (not shown), which can be moved from a basic position near the filling valve F, e.g. in the direction of the shaft 4, towards a pressing position. The filling chamber K is delimited by a filling chamber wall W, which extends to a shaft passage 3 and runs approximately parallel to the top of the valve element V. Part of the filling chamber wall W is an end wall 2 of an adjustment device E integrated into the housing 1, in which a release drive for the valve element V is provided. The adjustment device E is supported in the housing 1 by several support webs T running from the outside to the inside, between which several passages D are formed in the housing 1, which begin at the top of the housing 1 and open into the filling chamber wall W. The passages D are kidney-shaped. Part of the adjustment device E is a housing 5 placed on top, into which the shaft 4 of the valve element V extends. In the housing 5, a release piston 6 with seals 7 is slidably guided, which can be hydraulically actuated via an release channel 8 running through a support web T in order to move the valve element V downwards from the closed position shown into the fully open position not shown. The release piston 6 is loaded by a strong return spring 9, which is supported in the adjustment device E. On the shaft 4 there is a nut 10, which is expediently screwed to the shaft 4 and secured by a lock 11. The nut 10 is loaded by a weak suction spring 12 in the closing direction of the valve element V. A counter stop R is provided on the nut 10, which is aligned with a stationary stop S of the adjustment device E.

When the press piston (not shown) moves from its basic position, the valve element V is moved from the closed position shown to the fully open position, in which the nut 10 with its counter stop R hits the stop S. Pressure medium then flows through the passages D ₁ , 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 there is a large pressure difference between the passages D and the working chamber A,

has taken place immediately, the valve element V is moved back into the closed position by the suction spring 12. A pressing cycle is then carried out, which is controlled by means not shown, whereby the filling valve F remains in its closed position. In order to then return the press piston to the basic position, the release piston 6 is hydraulically actuated from the release channel 8, if necessary after a pressure reduction via a relief 20, in order to move the valve element V into the open position via the nut 10 and against the forces of the springs 9, 23. The pressure medium from the press cylinder is pushed out through the valve seat S, the filling chamber K and the passages D. The release piston 6 is then relieved of pressure and reset by the return spring 9. The suction spring 23 then guides the valve element back into the closed position.

When the valve element V reaches the open position, the counter stop R makes a hard impact 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 greater the larger the diameter of the valve seat P is selected. Since there is a tendency for ever larger valve seat diameters of the filling valve F for large high-performance presses and for the fastest possible press cycles, this load represents an acute danger to the functional reliability of the filling valve.

In the filling valve according to the invention as shown in Figs. 1, 2, 3 and 3A, this danger from the hard impact is eliminated in order to eliminate the functional reliability of the filling valve even with large valve seat diameters and many working cycles with high frequency. For this purpose, an impact damping device G is provided, which causes a softer impact and allows the impact energy to be consumed more slowly.

Components equivalent to components of the known filling valve (Fig. 4) are provided with the same reference numerals in Figs. 1 - 3A, so that a separate description should be unnecessary.

In the embodiment of the filling valve F according to the invention according to Figs. 1 and 2, the nut 10 is connected to the shaft 4 via a threaded connection 13, which is secured by the safety device 11. In addition, an expansion taper 12 is formed in the shaft 4, which serves as a flanking measure to protect the shaft 4 or the connection between the shaft 4 and the nut 10. The impact damping device G is arranged between the counter stop R of the nut 10 and the stationary stop S of the adjustment device E. In the embodiment shown, the shaft 4 is surrounded by an intermediate ring 14, which can be easily moved on the shaft 4 and contains an elastically deformable damping element 15, which works together with the stationary stop S to dampen the impact.

In Fig. 2 it can be seen that an inner bore 16 of the intermediate ring 14 surrounds the shaft 4 with radial play, but with a centering flange 17 engages over a circumferential shoulder 18 of the stop S in order to keep the shaft 4 free from braking friction forces. An annular groove 19 is formed in an underside 29 of the intermediate ring 14, in which the damping element 15 is positioned. The damping element 15 is ring-shaped and expediently consists of an O-ring that protrudes over the underside 29. The desired stroke of the shaft 4 until the fully open position is reached is indicated at X. The length of the nut 10 or the intermediate ring 14 is selected so that when the damping element 15 is largely relaxed, there is a stroke excess y within which the impact damping device G comes into effect. The suction spring 23 rests on a shoulder 21 of the intermediate ring 14 in order to secure it in the standby position shown and, if necessary, to slightly preload the damping element 15. The interior space designated 28 in the housing 5 is filled with pressure medium.

If the valve element is moved from the closed position shown in Fig. 2, right half, to the fully open position (left half), either by applying pressure to the release piston 6 or under the suction effect when moving the press piston (not shown) or by applying pressure on the side of the passages D, then

When the fully open position is reached, the counter stop R hits the intermediate ring 14, whereby the latter is adjusted via the stroke excess y until it stops on the stop S. The damping element 15 is elastically deformed in order to dampen the impact. As soon as the impact energy is used up, the damping element 15 can deform again and return the intermediate ring 14 to the standby position shown in Fig. 2, left side, in which the valve element V is in the fully open position. If the valve element V is then moved back to the closed position, the intermediate ring 14 remains in the standby position shown. Figs. 1 and 2 illustrate a mechanical impact damping device G.

In the embodiment of Fig. 3 of the filling valve according to the invention, a hydraulic impact damping device G is provided. For this purpose, a displacement projection 24 is provided on the nut 10, which simultaneously defines the counter-stop R. At the stationary stop S of the adjustment device E, an immersion recess 22 is formed for the displacement projection 24, which is connected to the chamber 28 via a connection 25 with a suction check valve 26 arranged therein. The outer diameter of the displacement projection 24 is matched to the inner diameter of the immersion recess 22 so that when the displacement projection 24 penetrates (Fig. 3, left half), pressure medium enclosed therein is pushed out upwards and throttled in the process until finally the counter-stop R hits the stop S. The impact energy is at least partially consumed. The suction check valve 26 blocks in this flow direction. If the valve element is subsequently to be moved back into the closed position, then the displacement projection 24 is pulled out of the immersion recess 22, whereby this movement is not slowed down by opening the suction check valve 26.

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

In the embodiment of the filling valve in Fig. 3A, a simple mechanical impact damping device G is provided without the intermediate ring 14 shown in Figs. 1, 2. The annular groove 19 is formed in the stop S, which positions the damping element 15 designed as an O-ring, which protrudes by the stroke excess y over the stop S in the direction of 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 to provide a damping element 15 on both the counter stop R and the stop S.

Claims (11)

Expectations 1. Hydraulically releasable filling valve (F) for a hydraulic press, with a valve element (V) ₁ which is adjustable relative to a valve seat (P) and has a shaft (4), the shaft (4) of which is arranged in an adjusting device (E) and can be brought by an unlocking drive against a restoring force from a closed position into a predetermined open position and with a counter-stop (R) provided on the shaft (4) against a stationary stop (S), characterized in that an impact damping device (G) is provided in the adjusting device (E) between the counter-stop (R) on the shaft (4) and the stop (S). 2. Filling valve according to claim 1, characterized in that the stop (S) is arranged offset from a desired stroke (X) of the shaft (4) between the closed and the open position (Vl ₁ VII) by a predetermined stroke excess (y) beyond the open position, and that the impact damping device (G) is effective exclusively within the stroke excess (y). 3. Filling valve according to claim 1, characterized in that the impact damping device (G) is effective exclusively in the stroke direction of the shaft (4) to the open position. 4. Filling valve according to claim 1, characterized by a hydraulic impact damping device (G). 5. Filling valve according to claim 1, characterized by a mechanical impact damping device (G) having at least one elastically deformable damping element (15). 6. Filling valve according to claim 1, characterized in that a nut (10) arranged on the shaft (4) can be brought into engagement with the stop (S) via the impact damping device (G) as a counter stop (S). 7. Filling valve according to at least one of the preceding claims, characterized in that an immersion recess (22) for a displacement projection (24) provided on the stop or the nut is arranged on the nut (10) or the stop (S), and that a suction check valve (26) is arranged between the immersion recess and a chamber (28) filled with pressure medium provided in the adjusting device (E). 8. Filling valve according to at least one of the preceding claims, characterized in that the elastically deformable damping element (15) is positioned on the nut (10), on the stop (S) or on an intermediate ring (14) displaceable on the shaft (4). 9. Filling valve according to claim 5, characterized in that the damping element (15) is annular, preferably as an O-ring inserted into an annular groove (19). 10. Filling valve according to claim 8, characterized in that the nut (10) is acted upon by a suction spring (23) in the direction of movement of the shaft (4) to the closed position, and that the suction spring (23) is supported on the intermediate ring (14) and secures the latter in a preferably pre-tensioned ready position positioning the damping element (15) at the stop (S). 11. Filling valve according to claim 8, characterized in that the intermediate ring (14) has a centering flange (17) which overlaps the stop (S).