DE2055882A1 - Longitudinal slide valve - Google Patents

Description

Qw 2224 11.11.70

Patent application

of the company

Union Eisenhütte Westfalia, 4628 Wethmar / Post Lünen

Longitudinal slide valve

The invention relates to a longitudinal slide valve O-ring seal, with the O-rings in groove-like chambers are held and the opening of one or more valve chambers by a relative movement between a slide piston and a valve housing is brought about and the annular gap between the slide piston and the valve housing have different diameters.

The invention has the purpose of using an O-ring to allow sealed longitudinal slide valve of the aforementioned type in the high pressure area.

It is known that when using such valves in the high pressure range the O-ring seals are torn from their seats and destroyed. The O-rings are pulled by the suction effect the flow of operating medium flowing through the valve chambers at high speed from the slot-ready chambers risen. To eliminate this suction effect, various measures have already become known, by means of which a pressure equalization should be reached on both sides of the O-ring seal. This is the case with a known type of Lengs slide valve it of the aforementioned type provided that the O-ring seals Associated with bodies made of porous metal, the

ORIGINAL

209821/0363

the metal bodies associated with the O-ring seals by virtue of their Porosity balances pressure on both sides of the O-ring seal should cause. A sufficient pressure equalization within a sufficiently short time can be achieved by means of porous metal bodies however, can only be achieved in the range of relatively low operating fluid pressures. When using an in this way designed longitudinal slide valve in the high pressure area the porous metal bodies are practically ineffective, as they are not able to equalize the pressure sufficiently Quickly convey why the O-ring seals during of changing course are also torn from their seats and destroyed here. In addition, this known type is liable Longitudinal slide valve still has the disadvantage that the use of sintered metal bodies requires a relatively high manufacturing cost of the longitudinal slide valve conditionally.

The invention is therefore based on the object of providing an O ~ ring sealed Longitudinal slide valve of the type described above to create the stability of its O-ring seals Even in the high-pressure area without use, an additional manufacturing expense is guaranteed means.

This object is achieved according to the invention in that the Zu- ™ and discharge channels are arranged in such a way that the part of the provided with recesses for mounting the O-ring seals Longitudinal slide valve (slide piston or valve housing) opposite the other part when opening relative to this in the direction of pressure moved in the opposite direction, but moved in the pressure direction when closing.

The O-ring seals are advantageously in annular grooves of the slide piston.

The inventive arrangement of the inflow and outflow channels as a function of the direction of movement of the slide piston ensures that the preferably on the spool

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arranged O-ring seal both during the opening as even during the closing phase due to the operating medium pressure prevailing in the valve chamber on the pressure side is held by a seat formed by an annular groove. Since the opening movement of the shut-off part, slide piston or valve housing, takes place against the direction of pressure builds up over the O-ring seal according to the decreasing degree of overlap between the spool or valve housing and the O-ring seal there is an increasing operating fluid pressure, which the O-ring seal holds in its groove-like seat. The reverse remains during the closing movement in the same direction as the pressure direction up to a complete overlap between the O-ring seal and slide piston or valve housing practically receive the full operating fluid pressure as holding force for the O-ring seal.

Of course, the invention is not limited to this in detail the illustrated embodiment is limited, rather the O-ring seal can also be arranged on the other valve part, so that with a displacement of the valve housing in the same Wise and similarly acting holding forces for the O-ring seal can be achieved, as is the case with the sealing arrangement on the slide piston described above.

The invention is described in the following example using two exemplary embodiments shown in the drawing described in detail. In the drawing shows the

Figure 1 is a more or less schematic representation of a longitudinal slide valve with inventive feed and Discharge channel arrangement;

FIG. 2 also shows a more or less schematic representation of a longitudinal slide valve designed according to the invention, However, with a valve housing that can be adjusted with respect to the slide piston.

In the embodiment shown in Figure 1 is in

2.0 ^ 821/0363

11/11/1970

an axial bore 1 of a valve housing 2 a slide piston 3 fitted to be axially displaceable. On both sides of a section of the axial bore 1 forming a valve chamber 4 there is one Inflow channel 5 and an outflow channel 6 are arranged. Which is made up of the arrangement of the inflow 5 and outflow channel it 6 resulting pressure direction of the equipment is indicated by the arrow 7. In the drawing, the slide piston 3 is shown in the open position. The slide piston 3 consists of a guide piston 8, a connecting rod 9 and a closing piston 10 and is adjustable by means of an actuating device 11 axially connected to the closing piston 10. Between the guide 8 and the closing piston 10 and the peripheral wall the axial bore 1 is each a gap 12, which by means of an annular groove 13 or 14 of the guide 8 or closing piston 10 arranged O-ring seal I5 or 16 is sealed.

The function of the longitudinal slide valve according to the invention is the following:

Starting from the open position shown in the exemplary embodiment, the closing piston 10 is opened for the purpose of shutting off the flow of operating medium 7 in the printing direction, i.e. in the direction of the arrow, to shifted to the right, at least until the closing piston 10 has exceeded the full cross section of the inflow channel 5. Included builds up over the O-ring seal 16 according to the decreasing Degree of coverage between valve housing 2 and the closing piston 10 an increasing operating medium pressure, which holds the O-ring seal 16 in its groove-like seat 14. Vice versa the opening movement of the closing piston 10 takes place against the pressure direction 7> wherein the closing piston 10 from its closed position, with regard to the drawing to the left in its illustrated Position, is moved. In the course of this opening movement, the closing piston exceeds 10 and in particular the O-ring seal 16 again the inflow channel 5 »whereby in turn, a pressure medium increasing in accordance with the decreasing degree of overlap between the closing piston 10 and the valve housing 1 the O-ring seal 16 results, which the 0-

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Gw? 2? 4

Ring seal 16 holds in the ring groove 14 forming the inner seat until they exceeded the cross section of the inflow channel 5 Has. The result is the same for both control movements of the closing piston 10 with regard to the O-ring seal 16 Relationships, with an essential factor therein for building up a suitable holding pressure over the O-ring seal 16 it can be seen that the pressurized operating medium has no flow in both directions of movement of the closing piston 10 speed as long as the O-Bing seal 16 located in the area of the inflow opening 5 ·.

In the exemplary embodiment according to FIG. 2, the valve design is reversed shown according to Figure 1, wherein a relative to a slide piston 25 adjustable in an axial bore 21 Valve housing 22, a valve chamber 24 · forming portion is provided. The spool 23 consists of a Closing piston 30, a connecting rod 29 and a guide piston 28, between the circumferential wall of the axial bore 21 and the closing piston 30 or the guide piston 28 in each case a gap 32 is present, which by a in a hanging groove 35 or 36 of the valve housing 22 arranged O-ring seal 37 or 38 is sealed. Inflow 39 and outflow channels 40 are arranged in the closing piston 30, the spacing of which is opposite lying cross-sectional edges of both channels 39 and 40 is smaller than the length of the valve chamber 24.

The function of this embodiment of the invention corresponds to the function of that shown in the first embodiment Embodiment.

For the sake of clarity of the drawing, a longitudinal slide valve is provided for each of the two exemplary embodiments shown with only one valve chamber, but the invention can of course also with longitudinal slide valves an arbitrarily large number of mutually aligned valve chambers can be used, in which case the inflow and outflow channels the valve chambers are arranged alternately one after the other.

2 ^r Ö§821 / 0363

Claims (2)

Γ _γ τ.γ PATENT CLAIMS: 1 .J Longitudinal slide valve with O-ring seal, the O-binge being held in groove-like chambers and the opening of one or more valve chambers being brought about by a relative movement between a slide piston and a valve housing and the annular gaps between the slide piston and the valve housing having different diameters
have, characterized by such an arrangement
the inflow (5> 39) and outflow channels (6.40) that the with
Recesses (14.36) for mounting the O-rings (16.38) provided part (slide piston 3 or valve housing 22) opposite the other part when opening relative to this the
Direction of pressure moves in the opposite direction, when closing, however, in
Print direction moved. 2. Longitudinal slide valve according to claim 1, characterized in that the O-rings (15,16) in annular grooves (13,14) of the slide piston (3) are stored. 209821/0363