CH639464A5 - HYDRAULIC PISTON CYLINDER DEVICE, IN PARTICULAR FOR DRIVING A FLOOR CLOSURE FOR METAL MELT CONTAINING vessels AND METHOD FOR PRODUCING THE SAME. - Google Patents

Description

639464 2

PATENT CLAIMS and coil core in the corresponding relative setting

1. Hydraulic piston-cylinder device, especially attached to the cylinder.

dere for driving a bottom closure for molten metal 13. The method according to any one of claims 10 to 12,

Containing vessels, with a position measuring device, characterized in that for fixing the induction coil

a rigid element connected to the stationary cylinder, in the corresponding relative position between induction coil element, which extends into the hollow piston rod, and coil core on the induction coil.

Induction coil element connected to an electrical control has a suitable number of spacers arranged.

element and one in the interior of the induction coil network.

elements arranged coil core, which is immovably connected to the piston rod, thereby marked io

net that the induction coil element (16) at one end

The invention relates to a hydraulic piston, as well as a stop surface (34), which is used for the position cylinder device, in particular for operating a base of the induction coil element (16) direct closure for vessels containing molten metal, according to or via at least one spacer (33) on one end face, the preamble of claim 1, and on a surface of the cylinder cover (20). drive to their manufacture.

2. Device according to claim 1, characterized in, In such designed devices, such as in DE-that the coil core (18) at the free end of a rod (17) is shown -AS 1299 432, the problem of the simple is brought up, which befe- at the other end on a stopper (19) -adjustment by Position measuring device is dependent, which is screwed into a thread in the hollow piston rod (6) 2 <> regardless of the piston position in such a way, against a shoulder formed therein. that there is a linear relationship over the entire stroke

3. Device according to claim 1 or 2, characterized thereby of piston position and signal strength is retained. This means in particular that the coil core (18) in the central opening is connected in particular if a plurality of position measuring devices are connected to one of the housings (27) of the induction coil element (16) by a single control, the signals of which process signals, for example, made of polytetrafluoroethylene .

piece (18a), which is connected to the wall of the device.

house is in sliding engagement. Drawing solved in claim 1 and in claim 10.

4. Device according to claim 3, characterized in the following an embodiment of the invention that the guide piece (18a) has a multi-wing shape with the help of the drawing. In it is:

passages lying between the wings. 30 Fig. 1 is a schematic representation of a metal casting

5. Device according to claim 3 or 4, characterized in that the slide closure of a casting vessel shows that, in the assembled state, the guide means (18a) is fitted between a shoulder (17a) by a hydraulic piston-cylinder device which is actuated by the spool, which in turn is controlled electrically, the rod (17) carrying the links (18) being formed, and the hydraulic piston-cylinder device with a position opposite end of the bobbin core (18) below - 35 tion measuring device is provided,

correct axial pressure is arranged. 2 is a sectional view held on an enlarged scale

6. Device according to claim 5, characterized in that the hy-provided with the position measuring device, that the coil core (18) on the end of the rod (17) -draulent piston-cylinder device,

screwed and secured in position. Fig. 3 is held on a further enlarged scale

7. Device according to one of claims 1-6, characterized 40 view of a part of the position measuring device, characterized in that the position device (15) is electrically coupled to a Fig. 4 an enlarged-scale sectional display instrument (10a). looks at a guide piece according to the invention,

8. Device according to claim 7, characterized in that: FIG. 5 is a view similar to FIG. 3, on the basis of which the display instrument (10a) is explained with a push button socket, a calibration of the position measuring device. (10) is physically united. 45 Figure 1 shows a slide closure designated 1

9. Device according to one of claims 1 to 8, characterized in a liquid metal container 2, from which a metal characterized that the position measuring device (15) flows with jet 3, for example, in a continuous casting mold 4. Which is electrically coupled to a recorder (11). Slider closure has a linearly movable slider part

10. A method for producing a hydraulic Kol- on the, via a releasable clutch with ben-cylinder device, not shown, according to claim 1, wherein the induct 50 of the piston rod 6 a double-acting hydraulic tion coil element (16) and the coil core (18) Matching piston-cylinder device 7 is preferably non-positively connected to the position measuring device to the actuating stroke of the cylinder and axially without play. A control slide 8 ensures that its position relative to one another is set, so that connection with an electrohydraulic drive device is characterized by the fact that the path-voltage curve of the device for the desired allocation of kinetic energy, position measuring device over the entire adjustment range 55, i.e. of hydraulic pressure medium to which the hydraulic pressure is determined and compared with a nominal profile, where the piston-cylinder device 7 (hereinafter referred to simply as the determined displacement of these profiles in terms of stroke as the hydraulic cylinder). The electrohydrau direction by appropriate setting of the relative position of the drive device has, among other things, According to the representation of the induction coil element (16) and coil core (18), a signal converter 9 and a push button socket 10 with display are equalized. 60 instrument 10a and a pen 11, the following

11. The method according to claim 10, characterized in be described in detail.

The position measuring device, as shown in FIG. 2 and the coil core of the coil core, is held in the hollow piston rod 6 of the hydraulically stationary and the induction coil element is missed piston for adjusting the relative position. Cylinder device 7 (hereinafter referred to as the plunger is referred to as hydraulic cylinder for the sake of simplicity)

12. The method according to claim 11, characterized in brought. At its right end according to FIG. 2 is the posinet that the position measuring device is connected to a line 12 after the unit measuring device 15 has been executed, and the position of the relative position between induction coil elements is in turn connected to the signal converter 9. The signal

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transducer 9 is with the push button socket 10 and with the display between the outer surface of the induction coil element 16

instrument 1 Oa connected and feeds the latter with signals and the wall of the passage 14 can enter pressure medium

depending on the received via the line 12, which through the opening 21 in the hydraulic signals. These signals have in turn reached the working position of the lik cylinder 7.

movable slide part 5 proportional. The display 5 The pressure medium opening 21 is eccentrically strument 10a in the cylinder 20 and is advantageously formed in the usual push button socket, and it is arranged with a central recess 20a in FIG. 10, which the pourer has for manual control of the connection, which in the exemplary embodiment shown is in a slide closure serves. the surface of the cylinder cover facing the piston 23. The piston rod 6 is formed on its left 20 according to FIG. 2. The recess 20a could alternatively also have a driver 13 at its end, which is a component of the coupling mentioned above in the surface of the piston 23 facing the cover 20, which forms a coupling in the axial direction. It serves to ensure, in the case of the eccentric pressure medium practically play-free connection between the piston rod 6 supply, that the pressure medium supplied serves itself and the movable slide part 5. The clutch is evenly distributed in such a way that concentric force is exerted on the exact match of the respective working pistons 23 (FIG. 2).

would be the movable slide part 5 and the piston rod 6. As can be seen in particular from FIG. 2 and already above

Described in a central longitudinal bore 14 of the piston rod 6, the induction coil element 16 is accommodated centrally in the position measuring device 15. The Posi cylinder cover 20 screwed in. As a result, the annular gap measurement device 15 has an induction coil element between the outer surface of the induction coil element 16

16 (FIG. 3), which is fastened at the right end according to FIG. 2 to one and the inner wall of the bore 14 to the cover 20 of the hydraulic cylinder 7 according to FIG. 2, and the front right face of the piston 23 is open, so that a direct one is screwed into an opening of the cover. The pressure medium connection between the said annular gap induction coil element 16 surrounds a coil core 18, which and the opening 21. It can be seen that the size is fastened to a rod 17, which in turn is attached to it according to the annular gap between the outer surface of the induction

Fig. 2 left end is attached to a plug 19. The coil element 16 and the inner surface of the piston rod

Plug 19 is fixed in the piston rod 6. The 25 bore 14 is essentially only critical in that the

Plug 19 is preferably screwed into a thread seen in the piston rod 6 to allow pressure medium to pass through the annular gap. For exact positioning.

tion of the plug 19 and thus the coil core 18 is formed in the pressure medium from the annular gap between the piston rod 6, a shoulder 19a, against which the outer surface of the induction coil element 16 and the InStop 19 is screwed, as can be seen from Fig. 2. 30 inner wall of the bore 14 into the interior of the induction coil element. With this design, not only does an exact positioning 16 flow, since this ensures that the coil core 18 is lined according to FIGS. 2 and 3, but also bends End is open, and because the bobbin 18 carries quemes exchanges. Rod 17 has a diameter which is smaller than the inner

The hydraulic cylinder 7 has a diameter of the hollow cylindrical induction coil element in its cover 20

Pressure fluid opening 21. In the same way, the Hy- 3516 is.

2 at its left end according to FIG. 2. It should also be noted that the hydraulic cylinder 7 is

Pressure medium opening 22. The pressure medium openings 21 cools. A cooling jacket 24 is provided for this purpose,

and 22 stand with the inside of the hydraulic cylinder 7 in the with inlet and outlet openings 25 and 26 for the

Connection, and by appropriate control which is provided with the coolant.

Connections connected to openings 21 and 22 (FIG. 1) can 40. The induction coil element 16 has a housing 27

Movement of the piston 23 within the cylinder causes corrosion-resistant to the pressure medium used.

will call. digematerial, e.g. made of non-magnetic, stainless steel

It can be seen that with each movement of the piston 23, by means of which the coils are hermetically sealed.

also the piston rod 6 and thus the coil spools. This means that the housing 27 so the coils

core 18 supporting rod 17 moves. This results for 45 probably on the outside as well as on the inside

each movement of the piston 23 surrounds or closes a relative movement in between.

see the coil core 18 and the coil device 16. In the embodiment shown, the inductor has

Accordingly, each working position of the movable tion coil element 16 corresponds to three coils 28, 29 and 30, which

Slider part 5 are arranged a certain relative position of the coil side by side and the total in the

core 18 and induction coil element 16. 50 housing 27 fixed in position by means of a casting compound

The induction coil element 16 points according to the figures. The middle coil 29 is the excitation coil, while the position has several individual coils. Preferably, the coil-side coils 28 and 30 are receiver coils, len device 16 is an induction coil combination, which is for the electrical connections of the coils 28 to 30 to each position of the coil core 18 relative to it a certain end of the induction coil element on the right according to FIG. proportional induced voltage. This voltage 55 tes 16 in an appropriate manner with pins 31a is connected via line 12 as a signal to the signal converter 9 of a plug part 31, which is applied in an opening of the G, which evaluates this signal accordingly. housing 27 is inserted and which can be connected with a corresponding piston rod 6 is practically permanently connected by pressure connector 31b which surrounds the end of the cable. This results in that provided within the colation 12.

The position measuring device 15 arranged on the rod 6 has a 60. As can further be seen, the housing 27 has a temperature-stabilizing effect in the area, so that the reference temp. according to FIG.

rature of the position measuring device 15 even during operation, no means which the induction coil element 16 experiences as a result of the large fluctuations. This in turn results in FIG. 2 right side in the cover 20 of the hydraulic cylinder

a comparatively high measuring accuracy. ders 7 can be screwed.

In addition, the position measuring device 15 is directly from 65. The coil core 18 preferably consists of a nickel

Pressure fluid is washed around because the diameter of the induction iron alloy is high permeability. The coil core 18 is guided coil element 16 smaller than the diameter of the bore via a guide piece 18a, which is inside the

14 is the piston rod 6. Housing 27 is arranged in the remaining annular gap and with the wall of the housing.

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ses 27 is in sliding engagement. The guide piece 18a can consist, for example, of polytetrafluoroethylene or the like.

The guide piece 18a has a multi-wing shape, and in the embodiment shown (FIG. 4) three wings 18b are provided. The wings 18b each lie with their outer surface against the wall of the inner opening of the housing 27. The wings 18b leave passages or openings between them through which pressure medium can pass.

The guide piece 18a is pushed onto the free end of the rod 17, and in the assembled position it is under a predetermined axial pressure between a shoulder 17a formed on the rod 17 and the opposite end of the coil core 18. The predetermined axial pressure is obtained in that the guide piece 18a is compressed between the rod shoulder 17a and the coil core 18. For this purpose, the coil core 18 is screwed onto the free end of the rod 17 to an appropriate extent. Due to the predetermined axial compression of the guide piece 18a, the outer surfaces of the wings 18b are pressed slightly against the wall of the inner opening of the housing 27, which in turn ensures that the coil core 18 is held in the desired position within the housing 27.

The diameter of the rod 17 carrying the coil core 18 is not critical. However, it should be smaller than the diameter of the guide piece 18a in order to avoid contact between the rod 17 and the interior of the housing 27.

It should be noted that the induction coil device can also be constructed differently than shown. It is only important that a specific output signal is obtained on line 12 for the entire stroke of piston 23 for each relative position between coil core 18 and induction coil element 16.

Various favorable effects are achieved by the arrangement described.

A first advantage is that very precise measured values are obtained, since the movement of the movable slide part 5 is used directly to generate measured values. This results from the fact that on the one hand the movable slide part 5 is connected directly to the piston rod 6 of the hydraulic cylinder via a practically backlash-free coupling, and that on the other hand the movable part of the position measuring device 15 is immovably connected to the piston rod 6.

Another advantage is that the position measuring device 15 can be conveniently installed and removed without dismantling the cylinder, so that it can be easily replaced.

The position measuring device 15 is not subjected to large temperature fluctuations during normal operation, so that the output signals can be used directly.

Finally, there is the advantage that the position measuring device can be arranged in a mechanically protected manner, since it is practically completely housed within the cylinder of the piston-cylinder device.

It should also be noted that the axial length of the position measuring device 15 and in particular of the induction coil element 16 is shorter than the axial length of the cylinder of the piston-cylinder device 7. Denncch is achieved that 23 linear proportionality of the output signals is obtained over the entire stroke of the piston.

It should also be noted that the illustration of the induction coil element 16 in FIG. 3 is a schematic illustration.

In practical embodiments, the different coils can overlap and in each other, for example

To be wound in accordance with the respectively desired control characteristic.

When using the invention to operate a bottom closure for vessels containing molten metal, considerable advantages are achieved because it is now possible to use an electrical control system by means of which control and monitoring of casting processes can be considerably facilitated. For example, it is possible to provide the display instrument already mentioned and to use it to clearly display the respective position of the movable slide part for the operator. At the same time, the positions of the movable slide part can be recorded with a pen, which enables a subsequent control of the casting process, for example including the control of plate wear.

It is also particularly advantageous if the display instrument 10a is physically coupled to the pushbutton socket 10. As can be seen in FIG. 1, the pushbutton socket 10 contains a plurality of actuation buttons which serve to cause desired movements of the movable slide part 5. If the display instrument 10a practically forms a physical unit with the push button socket 10, the operator can directly and immediately track and control the movements of the movable slide part 25 5 caused by actuating corresponding buttons by viewing the display instrument 10a.

It is also possible, with knowledge of the bath height in the pouring vessel, to bring the movable slide part 5 exactly into a position which corresponds to a desired outflow quantity per time unit.

In the case of continuous casting, the inflow of melt to the mold or to the tundish can be regulated in a simple and stable manner by feeding back the signal supplied by the position measuring device 15 to the control circuit, with which a setpoint value depending on the fill level in the mold or in the tundish Actual value comparison is made. This creates a comparatively simple path-dependent control.

Furthermore, a minimum step length can advantageously be introduced into the control in such a way that a predetermined movement length of the movable slide part 5 is produced each time the corresponding push button is actuated, however briefly. The minimum step length can be made adjustable.

Another advantage is that a memory can be provided in a simple manner, in which certain positions of the movable slide part can be stored. It is then possible to call up such specific positions of the movable slide part as required. This enables the use of programs for these processes.

It is also possible in a simple manner to provide a safeguard against the movable slide part being closed completely.

55 The use of the push button socket with display instrument allows the operator to be in any suitable place. The operator is therefore able to stay at a safe distance from the casting device, possibly even within a protected cabin.

In the described and illustrated embodiment, the position measuring device is located in the pressure medium flow. However, it is also possible to provide a dry arrangement of the induction coil element 16 in the piston rod 65 6, in which case seals are arranged between the outer surface of the induction coil element 16 and the wall of the piston rod bore 14. In addition, ventilation openings would have to be provided in this case.

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hen the space in which the position measuring device according to the present invention, however, it is preferred

device 15 is arranged, connect to the environment. Such, the coil device 28 to 30 relative to the coil

Vent openings could practically be shifted at the core 18 in FIG. 3 and fixed in the shifted position.

reproduced coil device 16 in the gen according to the figure. For this purpose, the coil housing 27 is provided on its right end part in such a way that it has a stop surface 34 on the inside of the 5 right end according to FIG. 5

Housing 27, in which the coil core 18 is arranged, which in the embodiment shown three distance

connect with the outside environment. Disks 33 are arranged loosely.

When using devices according to the inven- Is - still in the example shown -

There is still a problem with linearity that the shift of the zero point

the signals over the adjustment path of the position measuring device corresponds to x and x = 5 min, so it is around the zero point. It has already been said that it is desirable to align them with the ideal zero point,

Position measuring device inside the hydraulic piston required, with the position of the coil core 18 unchanged, to arrange the ben-cylinder device in order to position the housing 27 of the coil device 16 by 5 mm according to FIG. 5

essentially move the measuring device to the right in front of the harmful exterior. This is achieved in that

Protect influences, and to add a total of 33 additional washers to the existing spacers.

to get easy execution. However, this means again adding a total thickness of 5 mm,

um, that the length of the actual position measuring device On the other hand, it is assumed (not shown) that practically no longer than the actuating stroke of the piston-cylinder- the displacement in a practical position measuring device

It can be a device, if one does not want to extend the piston rod and device by about 5 mm compared to the ideal zero point afterwards, so that the cylinder is more understandable - it would be necessary to have the housing 27

wise is undesirable. Here, however, it is difficult to move the induction coil element 16 by 5 mm according to FIG. 5

relatively short length of the position measuring device to shift linearity to the left. This would be realized in the illustrated of the signals. In fact, this is only achieved by executing that - under the prerequisite -

reached the coil design as described here. tion that the spacers have a thickness of 2.5 mm

But even in this case the achievable linear loading corresponds to 25 - two of these disks 33 would be removed.

range is the maximum length of the stroke. After such a shift through relative movement

In the manufacture of position measuring devices between the coil core 18 and the induction coil element 16, however, there are unavoidable tolerances, specifically ensuring that the linear range of the position measuring devices

which corresponds in terms of the exact arrangement of the coils 28 to 30 direction 15 with the actuating stroke of the device,

and with regard to the magnetic properties of the coil 30, so that linearity of the signals

cores 18. This results in practice when a finished product is manufactured.

Device usually small axial displacements of the II. It must also be noted that in FIG.

near area. However, this means that a voltage-distance diagram is shown in the area of a hand. In

At the end of the travel range, the signals are no longer linear - this diagram shows the increase in line 3 due to the

are available. The present invention reproduces the sensitivity of the position measuring device,

have been proposed to ensure that the use of devices according to the

Most of the time, linearity of the signals over the entire actuating stroke, it may be desirable to have several such devices. to be controlled from a single control unit. In this case

In Fig. 5 the ideal zero line is denoted by 0, i.e. it is necessary that all position measuring devices not the line which, when corrected by the center of the induction 40 only with regard to the zero point, but rather

Coil element 16 and through the center of the permanent magnet also have the same sensitivity. According to one

18 goes, ideally the zero position of the position measurement in the preferred embodiment is carried out by

direction 15 represents. that a plurality of position measuring devices

1 and 2 are used to select the two ideal or theoretical lines that have similar

nien designated, which have the lateral boundary lines for 45 sensitivity. The sensitivities of the position measuring devices selected for the linear measuring range of the position measuring device 15 are then compared to one another.

represent. The sensitivity curve is labeled 3, fits so that they are essentially the same. This will

and it can be seen from FIG. 5 that this curve 3 is carried out within that the position measuring

Limits 1 and 2 is a straight line, so that in this area line device with the lowest sensitivity used preserves nearness of the signals. Turns 50. The sensitivity of the other position measuring devices

In practice, however, these ideal conditions can be reduced by the fact that the length of the spool

is not reached, and in FIG. 5 an steering core 18 is shortened as an example, preferably material possible deviation - according to manufacturing tolerances - evenly removed at both ends of the spool core 18 by corresponding broken lines 0 ', 1', 2 'and 3 'will. This ensures that the center of the measure

posed. It can be seen that in the case of the deviation which remains unchanged in a 55 gnet field and the field as a whole is

corresponds to practical execution, the zero point is changed compared to metric.

the ideal zero point by an amount of x according to FIG. 5. The working method for correcting or shifting the shifted to the left. In practice, this would mean the zero point of a position measuring device is as follows:

5 in the area of the right end of the actuating housing according to FIG. In order to avoid this prescribed means in a position measuring device, according to the invention a special measure-voltage-displacement diagram according to FIG. 5 is used. The linear range is shifted in such a way that it coincides with the diagram then with the range due to the constructive ideal. For the present case management of the ideal position measuring device that would mean that between the coil device 28 theoretical voltage-path diagram compared and the to 30 and the coil core 18 a relative movement by 65 deviation, expressed as a shift in the zero-point amount x must be caused. In general, it is possible to ascertain. This deviation (which lies on the path axis of the loan to leave the induction coil element stationary and lies in the diagram) then represents the measure for the coil core to be moved. In a practical embodiment, axial relative movement between induction coil

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element and coil core. The position measuring device is then arranged in the corrected relative position between the induction coil element and coil core on or in the hydraulic piston-cylinder device. As already explained above, the desired corrected relative position between the induction coil element and the coil core is achieved by correspondingly adding or removing spacers.

In order to be able to correct the relative position mentioned in both directions, the practical implementation of the position measuring device is such that the relative position between the induction coil element and the coil core, which corresponds to the ideal theoretical zero position, has already been achieved by using or arranging some spacers. Accordingly, to bring about a correction of this relative position, spacers can either be removed or spacers added.

5 As can be seen from FIG. 5, the stop surface is formed on a collar 35 which, as can be seen from FIG. 2, lies against the end face of the cover 20 when the induction coil element is attached, if there are no spacers 33. If spacers 33 are present, as is usually the case, the spacer 33 which is furthest away from the stop surface 34 lies with its free surface against the end face of the cover 20 when the coil device 16 is on the piston-cylinder device is arranged. 2, the distance plates 33 are not shown.

C.

4 sheets of drawings