EP3380257B1 - Volume flow regulating valve - Google Patents

Description

The invention relates to a volume flow control valve for controlling the volume flow of a fluid medium in two outlet channels. In addition, the invention relates to the use of such a volume flow control valve in a chock for rotatably supporting a roll neck of a roll in a roll stand for rolling preferably metallic rolling stock.

Volume flow control valves are fundamentally known in the prior art. B. from the EP 1 452 381 A1 , the EP 1 653 132 B1 , the GB 815 622 A or the DE 2051 949 A1 .

In particular the last-mentioned German patent application DE 2051 949 A1 discloses a volume flow control valve according to the preamble of claim 1. Specifically, this document discloses a volume flow control valve with a cylinder, in the cavity of which a dumbbell-shaped double piston is axially displaceably guided. The double piston consists of a first and a second piston, which are connected to each other via a tapered center piece. A central pressure chamber of the volume flow control valve is formed in the area of the tapered center piece. Springs are arranged on the end faces of the cylinder, which extend into the interior of its cavity and between which the double piston is held in a central position. A first and a second peripheral pressure chamber of the volume flow control valve are formed in the area of the springs. An inlet channel and a first outlet channel are provided in the cylinder for inlet and outlet of a fluid medium into the cylinder.

In addition to the volume flow control valves described, for. B. from the German patent application DE 103 36 894 A1 also chocks as oil film bearings for roll journals of a roll in a roll stand for rolling metallic rolling stock is known in the prior art. The chock disclosed there comprises a bearing bush which spans a cylindrical receiving space for the roll neck. On its inside, the bearing bush has, for example, two hydrostatic pockets, which are arranged essentially in a common axial line and can be fed with a coolant and / or lubricant via a check valve and through bores running in the bearing bush or the installation piece. Throttles in the bores should ensure optimal hydrostatic support of the roll neck even when the roll neck is inclined in the bearing bush.

The chokes, also called restrictors or orifices, perform precisely this function, but in practice only unsatisfactorily. In concrete terms, the throttles or restrictors are not suitable for distributing the volume flow of fluid medium or coolant and / or lubricant evenly over the two hydrostatic pockets, in particular not when the roll neck is inclined in the receiving space. In addition, the throttles or restrictors show high pressure losses, sometimes over 200 bar.

The German published application 2751082 discloses a volume flow control valve according to the preamble of claim 1.

The invention is based on the object of developing a known volume flow control valve, in particular for use in connection with an installation piece for storing roller journals, in such a way that the volume flow of the fluid medium in the outlet channels of the volume flow control valve also with different pressure ratios in the outlet channels is evened out.

This object is achieved with respect to the control valve by the subject matter of claim 1.

The term middle position also means symmetry position. In the claimed center position or symmetry position of the double piston, the opening cross-sectional areas released by the two outlet channels are greater than zero; ie in this In any case, the fluid medium can flow away from the center or symmetry position; in any case, the drainage channels are not blocked.

This claimed design of the volume flow control valve is the constructive prerequisite for solving the above-mentioned task, namely ensuring that the volume flows in the first outlet channel and in the second outlet channel can each be kept the same, even with different pressure conditions in the outlet channels.

The length L of the center piece of the double piston is, for example, equal to the distance 2d between the center axes of the first and the second outlet channel. Assuming that the first and second pistons of the double piston are cylinders, the end faces of which, also called control edges for the outlet channels, extend perpendicular to the center piece, this claimed length of the center piece ensures that - if the double piston is in the middle position - the first outlet channel through the first piston of the double piston and the second outlet channel through the second piston of the double piston are each only half closed.

To ensure an equal volume flow in both discharge channels even with different pressure ratios in the discharge channels, the double piston, also called valve spool, must be suitably positioned or suitable, i.e. H. depending on the pressure conditions in the drain channels. For this purpose, according to a second exemplary embodiment, the invention provides that a first pressure channel is provided for supplying the static pressure in the first discharge channel to the second peripheral pressure chamber and that a second pressure channel is provided for supplying the static pressure in the second discharge channel to the first peripheral pressure chamber.

In addition, it is provided that a first plunger is axially displaceably mounted in the first peripheral pressure chamber to act on the end face of the first piston of the double piston delimiting the first peripheral pressure chamber, the first plunger being able to act upon the total pressure in the first outlet channel is and that in the second peripheral pressure chamber, a second plunger is axially displaceably mounted to act on the end face of the second piston of the double piston delimiting the second peripheral pressure chamber, wherein the second plunger can be acted upon by the total pressure in the second outlet channel.

By means of the two measures described, namely supplying the static and total pressures to the peripheral pressure chambers, the double piston automatically adjusts itself according to a balance of forces which results from the pressure conditions and preferably also the spring forces in the two peripheral pressure chambers.

By acting on the peripheral pressure chambers with the pressures mentioned, the double piston is automatically positioned in relation to the outlet channels in such a way that the desired volume flow of the same amount is set in the outlet channels.

For the intended use of the volume flow control valve described in the following for chocks for storing support rolls in roll stands, it is advantageous if the volume flow control valve is designed for pressures of up to 2,000 bar.

The above object of the invention is further achieved by a chock according to claim 4. Accordingly, the chock is characterized in that a volume flow control valve according to the invention is provided for controlling the volume flow of the coolant and / or lubricant as a fluid medium in the receiving space of the chock. The first drain channel of the volume flow control valve is then connected to the first feed channel and the second drain channel is connected to the second feed channel for feeding the coolant and / or lubricant into the receiving space of the chock.

This claimed and inventive design of the chock advantageously ensures that even when the roll neck is inclined in the receiving space of the chock, the volume flows of the cooling and / or Lubricant in the two feed channels to the receiving space are always the same size.

In this respect, the advantages of the mounting piece claimed correspond to the advantages mentioned above with reference to the volume flow control valve according to the invention.

Further advantageous refinements of the volume flow control valve and the chock are the subject of the dependent claims.

Figur 1

das erfindungsgemäße Volumenstrom-Regelventil;

Figur 2

eine Detaildarstellung zu Figur 1; und

Figur 3

ein Einbaustück zum drehbaren Lagern eines Walzenzapfens einer Walze in Verbindung mit dem erfindungsgemäßen Regelventil

zeigt.The description is accompanied by 3 figures

Figure 1

the volume flow control valve according to the invention;

Figure 2

a detailed presentation Figure 1 ; and

Figure 3

a chock for rotatably supporting a roll neck of a roll in connection with the control valve according to the invention

shows.

The invention is described in detail below with reference to the figures mentioned in the form of exemplary embodiments. The same technical elements are denoted by the same reference symbols in all the figures.

Figure 1 shows the volume flow control valve 100 according to the invention. It essentially consists of a cylinder 110, in which a dumbbell-shaped double piston 120 is axially displaceably mounted. The term "axial" is used in the sense of the invention for the direction of movement of the double piston. The double piston 120 consists of a first piston 120-1 and a second piston 120-2, which are firmly connected to one another via a tapered central piece 126. The first and second pistons lie as tightly as possible against the cylinder wall. A central pressure chamber 130 of the volume flow control valve 100 is formed in the region of the tapered center piece 126. A first peripheral pressure chamber 150-1 and a second peripheral pressure chamber 150-2 are formed in the end regions of the cylinder, each of which is bounded by the end faces of the first and second pistons facing away from the center piece 126. At a central point, preferably halfway up the cavity of the cylinder 110, an inlet channel 160 is formed for supplying a fluid medium, for example a coolant and / or lubricant, with the aid of a pump device 250 into the central pressure chamber 130. To drain the fluid medium A central outlet chamber 170-1 and a second outlet channel 170-2 are formed in the central pressure chamber 130. The first and the second outlet channels 170-1, 170-2 each have the same axial distance d on both sides of the inlet channel 160. At the same time, the length L of the central piece 126 of the double piston 120 preferably corresponds to the distance 2d of the central axes of the first and the second Drain channel 170-1, 170-2. This ensures that - when the double piston 120 is in a central position - the first outlet channel 170-1 is closed by the first piston 120-1 and that at the same time the second outlet channel 170-2 is closed by the second piston 120-2 are that both share the same opening cross-sectional area.

A spring 140 is preferably arranged in each of the peripheral pressure chambers 150-1, 150-2 in order to hold the double piston in a central position, in particular when the volume flow control valve is not in operation. However, the springs 140 do not prevent the basic possibility of axially displacing the double piston 120 within the cylinder 110.

The above-mentioned object of the invention, namely to ensure the same volume flows in the first and second discharge channels 170-1, 170-2 even with different pressure conditions there, is achieved in particular by the peripheral pressure chambers 150-1, 150-2 of the Volume flow control valve are suitably pressurized with certain pressures. Specifically, the first peripheral pressure chamber 150-1 is subjected to the static pressure in the second drain line 170-2 for this purpose. Analogously, the second peripheral pressure chamber 150-2 is subjected to the static pressure in the first outlet channel 170-1. The application takes place via a respectively provided first and second pressure channel 180-1, 180-2.

Furthermore, a first plunger 190-1 is axially displaceably mounted in the first peripheral pressure chamber 150-1 for acting on the end face of the first piston 120-1 of the double piston delimiting the first peripheral pressure chamber. During the operation of the control valve, the first plunger 190-1 is acted upon by the total pressure in the first outlet channel 170-1 via a pressure channel. Analogously, a second plunger 190-2 is axially displaceably mounted in the second peripheral pressure chamber 150-2 for acting on the second peripheral pressure chamber 150-2 delimiting end face of the second piston 120-2 of the double piston. Again, analogously, the second plunger 190-2 is pressurized with the total pressure in the second outlet channel 170-2 via a pressure channel. The pressure channels are in Figure 1 shown as dashed lines.

Figure 2 shows the connection of the pressure channels for the static and the total pressure to the first or the second discharge channel 170-1, 170-2. Specifically, it can be seen that a fluid medium flows in the discharge channels 170-1, 170-2. This can be a coolant and / or lubricant, which from the central pressure chamber 130 to a consumer, e.g. B. flows a chock for rotatably supporting a roll neck. The fluid medium within the drainage channels shows a speed distribution as shown in Figure 2 is shown with reference number 1. A pitot probe, which is oriented in such a way that the fluid medium flows into the pitot probe, is provided to record the total pressure p _total in the discharge channel. Furthermore, an opening is provided on the wall of the drain channel 170, which represents the end of the first or second pressure channel 180-1, 180-2 for detecting the static pressure p _Stat in the drain channel.

During the operation of the volume flow control valve 100, the double piston 120 adjusts itself automatically or automatically in accordance with a balance of the forces acting on it. This equilibrium of forces is established in particular on the basis of the forces acting on the end faces of the first and second pistons 120-1, 120-2 facing away from the center piece 126. The forces are, on the one hand, the force which results from the action of the static pressures on the end faces of the first and the second piston and the force which is exerted by the tappets on the same end faces. The force exerted by the springs 140 on the same end faces also influences the balance of forces. The balance of forces determines the axial position of the double cylinder and thus also the ratio of the degree of opening of the first outlet channel to the degree of opening of the second drain channel. In accordance with this ratio of the degrees of opening, the volume flows in the first and the second outlet channels 170-1, 170-2 can be set to the same amount.

Figure 3 shows the said application of the volume flow control valve 100 according to the invention in connection with a chock 200. The chock 200 is used for rotatably supporting a roll neck 300 of a roll in a roll stand for rolling rolling stock. The chock 200 has a cylindrical receiving space 210, in which the roll neck 300 is rotatably mounted. The cylindrical receiving space is typically spanned by a bearing bush 220, which is inserted into the chock 200 as a wearing part. On the inner wall of the bearing bush 220, a plurality, typically 2 hydrostatic pockets 2, 3 are formed, through which the coolant and / or lubricant is pumped under high pressure into the receiving space 210, more precisely into the annular gap between the bearing bush 220 and the roll neck 300 becomes. For this purpose, the first outlet channel 170-1 of the volume flow control valve, also called the first feed channel, with the first hydrostatic pocket 2 and the second outlet channel 170-2 of the volume flow control valve, also called the second feed channel, with the second hydrostatic pocket 3 connected.

In particular for the use of the volume flow control valve 100 according to the invention in connection with the chock 200, it is advantageous if the volume flow control valve is designed for pressures up to 2,000 bar.

Reference list

1

Speed profile

2nd

Hydrostatic bag

3rd

Hydrostatic bag

100

Volume flow control valve

110

cylinder

120

Double piston

120-1

first piston

120-2

second piston

126

Centerpiece

130

central pressure chamber

140

feather

150-1

first peripheral pressure chamber

150-2

second peripheral pressure chamber

160

Inlet channel for the central pressure chamber

170-1

first drain channel for fluid medium from the central pressure chamber

170-2

second drain channel for fluid medium from the central pressure chamber

180-1

first pressure channel

180-2

second pressure channel

190-1

first pestle

190-2

second plunger

200

Chock

210

cylindrical recording space

220

Bearing bush

250

Pumping device

300

Roll neck

d

axial distance

L

Length of the middle piece

p _Total

Total pressure

p _Stat

static pressure

Claims (7)

1. Volume flow regulating valve (100), comprising:

   a cylinder (110) with a dumbbell-shaped double piston (120), which is guided in the cavity of the cylinder and which comprises a first piston (120-1) and a second piston (120-2), the pistons being fixedly connected together by way of a narrowed centre member (126),

   wherein a central pressure chamber (130) of the volume flow regulating valve is formed in the region of the narrowed centre member;

   a first peripheral pressure chamber (150-1) and a second peripheral pressure chamber (150-2) in the cylinder of the volume flow regulating valve, the chambers being bounded by the end faces, which are remote from the centre member (126), of the first and second pistons; and

   a feed channel (160) and a first drain channel (170-1) in the cylinder respectively for feeding a fluid medium to and draining a fluid medium from the central chamber (130);

   wherein in addition to the first drain channel (170-1) a second drain channel (170-2) for draining the fluid medium from the central pressure chamber (130) is provided and

   wherein the first and second drain channels (170-1, 170-2) are arranged at the cylinder at such an axial spacing 2d that when the double piston (120) is disposed in a centre setting with respect to the two drain channels the first drain channel (170-1) - preferably with partial covering by the first piston (120-1) - and the second drain channel (170-2) - preferably with partial covering by the second piston (120-2) - respectively free the same opening cross-sectional area;

   characterised in that a first pressure channel (180-1) is provided for supplying the static pressure in the first drain channel (170-1) to the second peripheral pressure chamber (150-2);

   a second pressure channel (180-2) is provided for supplying the static pressure in the second drain channel (170-2) to the first peripheral pressure chamber (150-1);

   a first plunger (190-1) is mounted in the first peripheral pressure chamber (150-1) to be axially displaceable for action on the end face, which bounds the first peripheral pressure chamber, of the first piston (120-1) of the double piston, wherein the first plunger (190-1) can be loaded by the total pressure in the first drain channel (170-1); and

   a second plunger (190-2) is mounted in the second peripheral pressure chamber (150-2) to be axially displaceable for action on the end face, which bounds the second peripheral pressure chamber, of the second piston (120-2) of the double piston, wherein the second plunger (190-2) can be loaded by the total pressure in the second drain channel (170-2).
2. Volume flow regulating valve (100) according to claim 1,
   characterised in that
   the volume flow regulating valve is designed for pressures up to 2,000 bars.
3. Volume flow regulating valve (100) according to any one of the preceding claims,
   characterised in that
   a respective spring (140) between which the double piston is held in the centre setting, but is axially displaceable, is arranged in each of the first and second peripheral pressure chambers (150-1, 150-2).
4. Chock (200) for rotatable mounting of a roll pin (300) of a roll in a roll stand for the rolling of material to be rolled, comprising:

   a cylindrical receiving chamber (210) for receiving the roll pin (300);

   a first feed channel (170-1) and a second feed channel (170-2) for the feed of coolant and/or lubricant to the receiving chamber (210); and

   an element for regulating the volume flow of the coolant and/or lubricant in the feed channels (170-1, 170-2);

   characterised in that

   the element is constructed in the form of a volume flow regulating valve (100) according to any one of the preceding claims;

   the fluid medium is formed as a coolant and/or lubricant; and

   the first drain channel (170-1) of the volume flow regulating valve (100) is connected with the first feed channel of the chock and the second drain channel (170-2) is connected with the second feed channel of the chock.
5. Chock according to claim 4,
   characterised in that
   at least one of the feed channels communicates with a hydrostatic pocket (2, 3) formed at the inner wall of the receiving space.
6. Chock according to claim 5,
   characterised in that
   the receiving space (210) is spanned by a bearing bush (220) inserted into the chock (200) as a wear component; and
   the hydrostatic pocket (2, 3) is formed at the inner side of the bearing bush (220).
7. Chock according to any one of claims 4 to 6,
   characterised in that
   a pump device (250) is provided for feeding the coolant and/or lubricant, preferably at pressures up to 2,000 bars, via the feed channel (160) to the central pressure chamber (130) of the volume flow regulating valve (100).

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