EP1854558B1 - Valve assembly - Google Patents

Description

The present invention relates to a valve assembly for a high-pressure cleaning device according to the preamble of one of the independent claims, a high-pressure cleaning device with such a valve arrangement and a use of a counter rod for closing force compensation.

High-pressure cleaning devices, also known as high-pressure cleaners, are commonly used for cleaning purposes. A liquid, in particular water, is pressurized by a high-pressure pump and usually discharged via a connected valve gun and nozzle. The high-pressure cleaning devices are usually provided with a valve assembly (unloader), so that when closing the valve gun or nozzle and the pump continues the liquid in the circuit is pumped, so the pump does not work against the closed valve gun or nozzle.

Such a valve arrangement is for example from the DE 198 38 947 C1 which forms the starting point of the present invention. The valve arrangement has a supply line which can be connected on the inlet side to the pump of the high-pressure cleaning device. On the outlet side, a pressure line to a valve gun o. The like. Connected. The supply line is provided with a check valve, which is opened in the conveying operation of the liquid flowing through and closes when closing the valve gun - ie collapse of the liquid flow - also.

Upstream of the check valve branches off a bypass line from the supply line leading to the suction side of the pump or a reservoir for the liquid, so that the liquid is conveyed with open bypass line from the pump in the circuit with low pressure drop.

The bypass line can be blocked by a bypass valve in normal Förderberieb. In particular, the bypass valve has a valve or closing body, act on the fluid pressure in the supply line and the force of a closing spring in the closing direction.

The closing body can be opened by means of an actuating device. The actuating device has a switching piston, which is movable against an adjustable spring force from the outlet pressure of the valve assembly against the closing body in the opening direction.

When the valve gun is closed, liquid flow through the check valve collapses and the check valve closes. At the same time, downstream of the non-return valve, a pressure pulse is generated which acts on the switching piston so that it lifts the closing body away from its associated valve seat, that is, initially opens the bypass valve. Next, the bypass valve is fully opened by a second, the closing body associated actuator. In this bypass mode, the check valve remains closed and the bypass valve remains open and the fluid from the pump is pumped through the bypass line unless it is turned off.

DE 100 33 075 A1 discloses an overflow valve having a valve piston which is withdrawn by fluid pressure from a bypass valve body to open a bypass.

The DE 43 28 382 A1 discloses a pressure washer with a valve assembly wherein a closure piston is opened by application of fluid pressure to a fixedly connected actuator piston to release a bypass.

The present invention has for its object to provide a valve assembly for a high-pressure cleaning device and a high-pressure cleaning device with a valve assembly and a use of a counter rod, wherein the valve assembly is universally applicable, individually configurable and / or customizable.

The above object is achieved by a valve arrangement according to claim 1 or by a high-pressure cleaning device according to claim 5 or by a use according to claim 7. Advantageous developments are the subject of the dependent claims.

One aspect of the present invention is to couple the bypass valve or its closing body with a working against the ambient pressure counter rod for closing force compensation. In particular, the effective cross section of the counter rod and thus the pressure relief to the pressure load or the effective diameter of the closing body or an associated valve seat are adaptable to keep the closing force acting on the closing body in the closed state constant even with different diameters for different flow rates.

This is in turn a universal applicability of the valve assembly conducive, in particular where largely the same parts for different pressures and / or flow rates - especially at different diameters of the sealing seat of the bypass valve - are used,

Fig. 1

eine blockschaltbildartige Ansicht einer vorschlagsgemäßen Ventilanordnung mit einer zugeordneten Hochdrucksreinigungsvorrichtung und einer über eine Druckleitung daran angeschlossenen Ventilpistole; und

Fig. 2

einen schematischen Schnitt der Ventilanordnung im Förderbetrieb.

Further advantages, aspects, features and characteristics of the present invention will become apparent from the claims and the following description of a preferred embodiment with reference to the drawing. It shows:

Fig. 1

a block diagram-like view of a proposed valve assembly with an associated high-pressure cleaning device and a valve connected thereto via a pressure line valve gun; and

Fig. 2

a schematic section of the valve assembly in the conveying operation.

Fig. 1 shows an overview of a proposed valve assembly 1, which is assigned in particular a high-pressure cleaning device 2 in the aforementioned sense. In particular, the valve assembly 1 is connected to the high-pressure cleaning device 2, particularly preferably attached to this or built into this or integrated in any other way.

The valve arrangement 1 is connected to a pump 3, in particular a high-pressure pump, the high-pressure cleaning device 2 for supplying or supplying a liquid 4, in particular water or another cleaning liquid. In principle, the valve arrangement 1 can also be connected to another pump, water supply or the like, and / or also be used for other purposes.

The present invention particularly relates to applications in which the pressure of the liquid 4 or the pump 3 is at least 5 MPa, preferably 10 to 50 MPa, in particular about 30 to 50 MFa, or even more.

The liquid 4 is taken in particular from a reservoir, such as a tank 5, but the liquid 4 can also be pumped in some other way be fed, for example, directly through a water hose, a water network o, the like.

The valve assembly 1 has a supply line 6, on the inlet side of the preferably high-pressure liquid 4 can be fed. In particular, the valve arrangement 1 or supply line 6 is connected to a connection or inlet 7 to the pump 3.

To the supply line 6 is on the outlet side - in particular to an outlet or terminal 8 of the supply line 6 - preferably a pressure line 9, in particular a hose connected, the or the high-pressure liquid 4 of a valve device, in particular a valve gun 10 o. Like., For the output of the liquid 4 preferably via a nozzle 11, in particular in the form of a spray jet, 12 zuleitet.

The valve gun 10 with the nozzle 11 can also be understood as a nozzle head. Further, the nozzle 11 may optionally be directly as in Fig. 1 represented, or in the usual way via a spray lance o. The like. To the valve gun 10 or other suitable valve device, which allows in particular a selective and / or manual opening and closing of the liquid output, be connected.

Fig. 1 shows the liquid dispensing and valve assembly 1 in the normal conveying operation. The liquid 4 is discharged continuously and in particular as a jet 12 via the opened valve device or valve gun 10 and connected nozzle 11.

During the conveying operation, the liquid 4 is discharged at the outlet 8 at a relatively high pressure, which in particular substantially corresponds to the said pump pressure. This outlet pressure is referred to in the conveying operation as working pressure.

In the delivery mode, the valve assembly 1 can serve to set and / or limit the outlet pressure or working pressure. This will be discussed later.

If the output of the liquid 4, in particular by closing the valve gun 10 o. The like. Locked, prevents the valve assembly 1, that the pump 3 operates against the closed valve gun 10 and, if necessary, even lying above the working pressure in the pressure line 9 builds up , This would be very dangerous at pressures of, for example, 50 MPa or more and could lead to injuries, in particular in the case of an unwanted opening of the valve gun 10. Further, this would lead to a very strong and unwanted recoil each time the valve gun is opened. In order to avoid this, the valve assembly 1 with closed valve device or valve gun 10, the liquid 4 supplied from the pump 3 via a bypass or back, in particular in the liquid reservoir or to the inlet or inlet of the pump 3, in particular so that the liquid 4 is preferably conveyed in the circulation with preferably only a low flow resistance. This operation is referred to as bypass operation in the present invention. Accordingly, the valve assembly 1 is often referred to as Bypaßventilanordnung or unloader.

The valve assembly 1 has in the supply line 6, in particular designed as a check valve 13 check valve, which closes or closes automatically in particular when the liquid flow through the supply line 6, in particular by closing the valve gun 10, collapses, ie in the subsequent bypass operation. The check valve ensures that the working pressure or outlet pressure is maintained on the outlet side.

For realizing the bypass, the valve arrangement 1 has, in particular, a bypass line 14 and an associated bypass valve 15. The bypass line 14 branches off upstream of the check valve from the supply line 6, so that the already mentioned return of the pumped from the pump 3 4 liquid in bypass mode and in particular their promotion is made possible in the circulation. For this purpose, the bypass line 14 is connected in the illustrated example, in particular via a return line 16 to the liquid reservoir or the input side of the high pressure pump 3. Alternatively, however, the return line 14 can serve only a derivative of the funded by the pump 3 liquid 4 in the bypass mode, without the derived liquid 4 is conveyed in the bypass operation in the circulation.

The bypass valve 15 is controlled in particular in response to the downstream of the check valve pending outlet pressure, as indicated by the dashed line in FIG Fig. 1 indicated and explained later in more detail.

In particular, the valve assembly 1 is formed such that at the transition from the delivery mode into the bypass mode - ie in particular when closing the valve gun 10 - first the liquid flow through the supply line 6 and through the check valve collapses and the check valve - in particular automatically due to corresponding spring preload o - closes. Next arises in the usually abrupt closing of the liquid output, in particular the valve gun 10, a pressure pulse in the pressure line 9, so a sudden or pulse-like increase of the downstream of the check valve pending pressure or outlet pressure. This pressure increase is preferably used to open the bypass valve 15, in particular at least initially, in order to switch the valve arrangement 1 into the bypass operation or to release the bypass line 14.

If the liquid output - especially the valve gun 10 - is opened again, first the outlet-side pressure (holding pressure) drops significantly, possibly down to 0. This pressure drop preferably leads to the bypass valve 15 - in particular automatically by spring force and / or by the liquid flow or by the fluid pressure in the supply line 6 and / or bypass line 14 - is closed again. Alternatively or additionally, said pressure drop can also be evaluated or detected in order to turn on the high-pressure cleaning device 1 or feed pump 3 again, wherein the bypass valve 15 is then closed again in the sequence.

With closed bypass valve 15, the promotion of the liquid 4 through the pump 3 leads to a quasi-immediate increase in pressure in the supply line 6 and the corresponding opening of the check valve, so that the promotion of the liquid 4 and output via the pressure line 9, valve gun 10 and nozzle 11 starts again , The conveyor operation is thus resumed and the outlet side of the working pressure is reached again.

It should be noted that the supply line 6 is to be understood in particular as a line in the functional sense, ie as a fluidic connection, and in particular from a plurality of channels, passages, bores o. The like. Can be constructed or formed. The same also applies to the bypass line 14 and / or bypass line 18 or other fluidic connections, lines o. The like. The valve assembly 1 and the high-pressure cleaning device. 2

Hereinafter, first, a preferred construction of the proposed valve assembly 1 based on Fig. 2 explained, showing the valve assembly 1 in a schematic section in the conveying operation.

The illustrated valve arrangement 1 has a housing 20, in which preferably all components and components of the valve arrangement 1 are received or to which they are preferably arranged.

The check valve is, as already mentioned, preferably designed as a check valve 13. In the illustrated embodiment, it has a valve body 21 which is biased by an associated spring 22 in the closing direction against a valve seat against the dispensing or main flow direction through the supply line 6. In particular, the check valve is inserted or installed in an outlet 8 forming the bore of the housing 20. Particularly preferably, the check valve or check valve 13 has no seal, but seals directly with its slope of the valve piston directly on the housing.

At the outlet 8 is preferably a connection device, such as a quick coupling, for connecting the pressure line 9, in particular a hose provided.

The valve assembly 1 further comprises an actuating device 23 with an actuator, in particular a switching piston 24, for actuation, in particular for opening a valve or closing body 25 of the bypass valve 15. The actuator or the control piston 24 is preferably independent or separated from the closing body 25 movable, so preferably not fixedly connected to this.

Preferably, the biasing force is adjustable, for example by means of a spindle adjustment, a preferably rotatable handle 27 o. The like. In a withdrawn from the closing body 25 rest position preferably biased by spring force.

The setting of the biasing force is used to set the maximum Beriebsdrucks the valve assembly 1. The adjustment is made in particular by turning the handle 27. Particularly preferred is a backup or a final set by a lock nut, clamping screw o. The like. Possible, as indicated in the drawing.

Between the main spring 26 and the control piston 24, a shim may be provided in particular for compensating lateral forces in the pressure adjustment.

Preferably, the switching piston 24 extends through an actuating chamber 28 and sealed in an adjacent bypass chamber 29 which is fluidly connected to the supply line 6 with open bypass valve 15 and to the preferably transverse to the supply line 6 extending bypass line 16 forms or forms.

The operating space 28 is connected via a control channel 30 to the supply line 6 downstream of the check valve, so that the outlet pressure act on a piston 28 formed in the actuating chamber 28 from the piston 24 piston area and thereby the switching piston 24 in the direction of the bypass valve 15 and closing body 25 against the force the main spring 26 can bias or move.

The bypass valve 15 has, as already mentioned, the movable closing body 25 and an associated valve seat 32 which is formed or arranged in particular at the transition from the supply line 6 to the bypass chamber 29 or at another suitable portion of the bypass line 14.

The bypass valve 15 is in particular inserted or installed in a bore or opening of the housing 20, which extends in particular transversely to the preferably rectilinearly extending through the housing 20 supply line 6 and / or is arranged upstream of the check valve.

Particularly preferably, the bypass valve 15 is formed such that the pressure prevailing in the supply line 6 upstream of the check valve fluid pressure pushes the biasing valve 15 and the closing body 25 in its closed position or position against the valve seat 32 or biases.

The bypass valve 15 preferably has a closure member 25 associated with the closing spring 33, which biases the closing body 25 in the closed position against the associated valve seat 32.

The bypass valve 15 or closing body 25 is assigned as a guiding or adjusting means a counter rod 34, which is preferably fixedly connected to the closing body 25. In the illustrated example, the closing spring 33 surrounds the counter rod 34 peripherally and is, for example, resisted to a housing part 35, which is preferably releasably attached to the housing 20. The article 34 extends from the pressurized by-pass valve 15 or the pressurized supply line 6 out into the outdoor region under ambient pressure, preferably sealed by the housing 20 and the housing part 35 o. The like. Through. The counter rod 34 thus operates against the ambient pressure, so that, depending on their diameter (through the housing 20 or housing part 35 in the outer space), a partial compensation of the force acting on the shooting body 25 by the fluid pressure force or a corresponding reduction of the resulting for the closing force relevant surface (area of the effective sealing seat of the bypass valve 15 minus cross section of the counter rod 34) takes place. The counter rod 34 is preferably exclusively the closing force compensation.

Fig. 2 shows the valve assembly 1 in the conveying operation. The liquid 4 flows through the supply line 6 and is discharged with the working pressure (eg. 30 to 50 MPa) at the outlet 8 to the pressure line 9 and the valve stole 10 and nozzle 11 as a beam 12 output. The check valve is opened by the liquid flow against the force of the spring 22.

The working pressure exerts in the operating chamber 28 a force on the piston portion 31, so that the force of the main spring 26 overcome and the actuator 23 and the switching piston 24 is advanced in the opening direction against the closing body 25 and is. However, the bypass valve 15 (normally) remains closed in the conveying mode, the closing body 25 is not (yet) lifted off its valve seat 32. In particular, the liquid pressure acting on the closing body 25 in the supply line 6 and the closing spring 33, which act in the closing direction, ensure that the bypass valve 15 (normally) remains closed in the conveying mode.

However, when the discharge pressure becomes too high (excessively rising), the actuator 23 applies a correspondingly higher force to the closing body 25, in particular with its switching piston 24, so that the bypass valve 15 is opened and the bypass valve 15 in this case as an overload valve or safety valve can act to limit the pressure.

If the liquid output is blocked, in particular by closing the valve gun 10, a transition or switching from the delivery mode into the bypass mode takes place.

First, the liquid flow breaks through the check valve so that it closes. The blocking of the liquid dispensing or the closing of the valve gun 10 o. The like. Further leads to a pressure pulse (momentary jump in the outlet pressure), so that now the actuator 23 by means of the already applied to the closing body 25 control piston 24, the bypass valve 15 very quickly and / or at least initially opens, whereby the prevailing until then in the bypass valve 15 on the side of the supply line 6 fluid pressure drops very quickly and this leads to an easier further opening of the bypass valve 15. In particular, the actuator 23 causes the complete opening of the bypass valve 15 in the transition to the bypass operation.

Only when the valve gun 10 is opened again does the outlet pressure collapse. This causes the pressure in the operating chamber 28 drops and accordingly the closing body 25 due to the force of the closing spring 33 returns to its closed position, the bypass valve 15 thus closes. The valve device 1 then returns to the in Fig. 2 shown state of the conveying operation back.

The valve arrangement 1 is designed in particular for very high volume flows of, for example, 30 to 60 l / min. This allows universal use for different purposes or with different pumps 3 or high-pressure cleaning devices 2.

At higher flow rates, a larger diameter of the closing body 25 and the associated valve seat 32 and the sealing seat is required, in particular in order to achieve a sufficiently low flow resistance in the bypass operation, in particular at the same opening stroke. However, then correspondingly increases the acting in the closing direction surface of the closing body 25. This normally requires a substantial increase in the opposing effective area of the piston portion 31 and the actuator 23 and / or in particular a much greater dimensioning of the main spring 26 and all components associated with it to withstand the much higher forces.

The present invention now goes another way. By means of working against ambient pressure counter-rod 34 is a compensation.

By increasing the diameter of the counter rod 34, it is namely possible to compensate for an enlarged sealing seat of the bypass valve 15, the area increase, so that the resulting effective in the closing direction surface preferably remains constant or substantially equal. A cross-sectional increase at the sealing seat is thus achieved by a surface corresponding increase in the diameter of the counter rod 34. Accordingly, then a change in the other components, in particular the actuator 23, no longer required. Consequently, with very little effort and using a variety of Similar to a family of valve assemblies 1 are created for different flow rates and / or working pressures.

The valve assembly 1 is particularly preferably designed for working pressures of about 35 to 70 MPa. In Bypaßbetrieb - ie with closed spray or, valve gun - there is a reduction of the pressure in the hose or in the pressure line 9 and in the gun 1 0, for example, at most 5 MPa.

LIST OF REFERENCE NUMBERS

1

valve assembly

2

High-pressure cleaning device

3

pump

4

liquid

5

tank

6

supply line

7

Inlet

8th

outlet

9

pressure line

10

valve gun

11

jet

12

beam

13

check valve

14

bypass line

15

bypass valve

16

return

20

casing

21

valve body

22

feather

23

actuator

24

switching piston

25

closing body

26

mainspring

27

handle

28

operating space

29

Bypaßraum

30

control channel

31

piston section

32

valve seat

33

closing spring

34

counter-link

35

housing part

Claims (7)

1. Valve assembly (1), which can be supplied with a liquid (4) under high pressure, in particular by a high-pressure cleaning device (2) or pump (3), and can be operated selectively in a conveying mode or bypass mode,
   with a supply line (6) which can deliver the liquid (4) on the inlet side, in conveying mode the liquid (4) being dischargeable on the outlet side with a working pressure, in particular via a connectable pressure line (9) or valve device, such as a valve gun (10),
   with a stop valve in the supply line (6), which stop valve in particular is designed as a non-return valve (13) and allows the liquid (4) to flow through in conveying mode and closes in bypass mode,
   with a bypass line (14) which is connected, upstream of the stop valve, to the supply line (6), in order in bypass mode to return the liquid (4), in particular, to the high-pressure cleaning device (2), the pump (3) or a liquid reservoir,
   with a bypass valve (15) having a closing body (25) for shutting of the bypass line (14) in conveying mode, the closing body (25) being prestressed or pressed into the closing position by the liquid pressure,
   with an actuating device (23) for the preferably complete opening of the bypass valve (15) in bypass mode and/or when a maximum outlet pressure of the supply line (6) is overshot in conveying mode,
   characterized in
   that, the valve arrangement (1) has a counteracting rod (34), coupled to the closing body (25), solely for the at least partial compensation of the closing force acting upon the closing body (25) as a result of the liquid pressure, the counteracting rod (34) extending, sealed off, out of the bypass valve (15) which is under liquid pressure into an outside region which is under ambient pressure, and the counteracting rod (34) working counter to the ambient pressure, so that a corresponding reduction in the resultant area relevant for the closing force occurs.
2. Valve assembly according to Claim 1, characterized in that the bypass valve (15) or its closing body (25) is prestressed or pressed into the closing position by a closing spring (33) and/or by the liquid pressure in the supply line (6) upstream of the stop valve.
3. Valve assembly according to one of the preceding claims, characterized in that the actuating device (23) is actuable in the opening direction counter to spring force and/or has a switching piston (24) which is fluidically connected to the supply line (6) in such a way that the said switching piston is moved or prestressed against the closing body (25) of the bypass valve (15) in the opening direction by the working pressure out of a position of rest disengaged from the closing body (25).
4. Valve assembly according to Claim 3, characterized in that the switching piston (24) is prestressed into the position of rest by means of a main spring (26), so that the switching piston (24) is moved back into its position of rest when the outlet pressure falls to the holding pressure.
5. High-pressure cleaning device (2) having a valve assembly (1) according to one of the preceding claims.
6. High-pressure cleaning device according to Claim 5, characterized in that a pressure line (9), in particular a hose, is connected by means of a valve gun (10) to the valve assembly (1), in particular the outlet (8) of the latter.
7. Use of a counteracting rod (34) extending, sealed off, out of a valve (15) which is under liquid pressure, for the at least partial compensation of a closing force acting upon a closing body (25) of the valve (15) as a result of the liquid pressure, into an outside region which is under ambient pressure, so that, in the case of a specific liquid pressure, a specific closing force acts upon the closing body (25), in a valve assembly (1) according to one of Claims 1 to 4, the diameter of a valve seat (32) of the valve (15) and/or the diameter of the closing body (25) being varied as a function of a desired volume flow through the valve (15), and the diameter of the counteracting rod (34) being varied for the adaptation of compensation, so that, in the case of the specific liquid pressure, the closing force at the particular liquid pressure or the resultant area acting in the closing direction remains at least essentially identical.

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