EP2814637B1 - Water abrasive suspension cutting system - Google Patents

Description

The invention relates to a water-abrasive suspension cutting system with the features specified in the preamble of claim 1 (see, for example EP-A-1 199 136 ).

In water-abrasive suspension cutting systems high-pressure water, an abrasive is added. Subsequently, the water is applied with the abrasive as a suspension from a nozzle, wherein the nozzle generates a high-pressure suspension jet, which can be used for cutting a variety of materials, such as steel, concrete, etc. In these systems, there is the problem of introducing the abrasive in the high pressure area of the system. It is known to fill a pressure vessel in the pressureless state with the abrasive and then after closing the pressure vessel to direct the high pressure water through this pressure vessel, which then comes in the pressure vessel to a mixture of water and abrasive. In these systems, there is the problem that after emptying the pressure vessel, the system must be brought into a depressurized state to refill the pressure vessel with abrasive. Ie. it comes here to a business interruption. In this respect, it is desirable to be able to introduce abrasives into the high-pressure region during operation of such a system.

In view of this problem, it is an object of the invention to provide a water-abrasive suspension cutting machine, which has an abrasive agent supply device, which makes it possible in the ongoing Operation to be able to introduce abrasive into the pressure range of the system.

This object is achieved by a water-abrasive suspension cutting system with the features specified in claim 1. Preferred embodiments will become apparent from the subclaims, the following description and the accompanying figures.

The water-abrasive suspension cutting system according to the invention has, in a known manner, a high-pressure source, for example a high-pressure pump, which provides water under high pressure. This is a very high pressure, preferably a pressure of up to 2,500 bar or higher. Furthermore, the system has an outlet nozzle through which the pressurized water mixed with abrasive emerges for cutting. The exit nozzle is connected to the high pressure source via a high pressure line, with an abrasive supply means connected to the high pressure line. Ie. As usual in the suspension cutting process, the mixture between water and abrasive in the high pressure region of the system upstream of the outlet nozzle. For this purpose, for example, at least a portion of the high-pressure water is passed through a pressure vessel in which the abrasive is located. In the pressure vessel then comes to a mixture between water and abrasive. The water flushes the abrasive out of the pressure vessel and carries it up to the exit nozzle where it then exits for cutting along with the abrasive.

The abrasive supply means serves to introduce during operation of the plant abrasive in the high pressure area, ie in the high pressure line without having to take the plant out of operation and in particular without the high pressure area or a part to bring the high-pressure area in a non-pressurized state. In addition, the abrasive supply to the high pressure region is preferably such that no air is introduced into the high pressure region.

According to the invention, the abrasive-supplying device has a lock with a rotary body, which is rotatably driven about an axis of rotation. The rotary body is provided in a circumferentially extending around the axis of rotation, ie a concentric with the axis of rotation peripheral region with a plurality of circumferentially spaced recesses. These depressions serve to receive abrasive or an abrasive-water mixture for supply to the high pressure area. For this purpose, an opening of an abrasive supply line facing the peripheral region. The mouth lies in front of a circumferential line, on which the recesses are arranged. Thus, abrasive can enter from the supply line into a recess, if this has been brought with a corresponding rotation of the rotary body in a position opposite to the mouth. In addition, the said peripheral region faces an inlet opening into the high-pressure line, so that, when a depression of this inlet opening is opposite, abrasive medium can escape from the depression into the inlet opening and into the high-pressure line. The inlet opening and the mouth of the abrasive supply line are the peripheral region and in particular a circumferential line on which the recesses are formed on the peripheral region, so that the depressions by rotating the rotary body about the rotation axis alternately into a position opposite to the mouth and one of Inlet opening opposite position are movable. Upon rotation, thus, a depression first comes in a position opposite the mouth of the abrasive supply line, so that the abrasive can enter the depression. By further rotation becomes Then the same depression is then placed in a position opposite the inlet opening of the high-pressure line, where the abrasive then exits the recess again and enters the high-pressure line.

The inlet and outlet of the abrasive from the wells is preferably carried out by gravity. For this purpose, the mouth of the abrasive supply line is preferably arranged above the rotary body, while the inlet opening is arranged in the high pressure line diametrically opposite below the rotary body. Thus, the abrasive enters a depression when it is located at the top of the rotating body and out of the cavity when the depression is located at the bottom of the rotating body and opened to the bottom, respectively. The axis of rotation preferably extends in the horizontal direction. By continuous or clocking rotation of the rotating body, the plurality of wells are alternately and sequentially in the manner described with the mouth of the abrasive supply line and then brought into line with the inlet so that continuously abrasive in the size of the wells corresponding portions in the high pressure line can be inserted.

The abrasive can be introduced from the abrasive supply line in loose form in the wells. However, it is also conceivable that the abrasive is portioned beforehand and, for example, enters the depressions from the abrasive agent supply line into a mold pressed into frozen or frozen pellets.

The rotary body is particularly preferably spherical. The peripheral region lies on the circumference of the spherical body. When using a spherical body, the recesses are preferably located on a circumferential line of the spherical body with the spherical radius, wherein this circumferential line extends around the axis of rotation. The ball body need not be formed as a full ball, but the rotary body may have only the central region of a ball, two diametrically opposite end portions may be flattened or cylindrical for connection to a drive shaft or for receiving seals and / or bearings. In particular, the spherical body can pass directly into the drive shaft.

More preferably, the mouth of the abrasive supply line is arranged surrounding a voltage applied to the peripheral region of the rotary body seal. This seal preferably seals the high pressure area formed by the high pressure line from the abrasive supply line. Ie. In this embodiment, in the environment of this seal, d. H. the surrounding area of the rotating body are water at said high pressure. A transition into the abrasive supply line is prevented by the seal. Alternatively or additionally, a seal in the peripheral region of the inlet opening in the high pressure line may be arranged so that it comes to rest on the peripheral region of the rotating body. If only one seal is provided in the peripheral region of the mouth, this has the advantage that the high pressure acts on the diametrically opposite side of the rotating body and thus presses against the seal in abutment.

The gasket is preferably configured such that, when a depression of the mouth is opposite, it abuts circumferentially the depression on the surface of the rotating body, ie the peripheral region of the rotating body. Furthermore, the seal preferably has a width which is greater than the width or the diameter of the depressions in the direction of rotation. This ensures that even if a depression passes through the seal, via the wells no connection between the high pressure area and the abrasive supply line.

On the side facing away from the rotary body of the seal, a pressure element is preferably arranged, which holds the seal on the peripheral region of the rotating body in abutment. The pressure element may for example be provided with a spring element in order to generate a contact force which presses the seal against the surface or the peripheral region of the rotary body. Alternatively or additionally, the seal can generate such a contact force due to its own elasticity by compression over the pressure element.

The pressure element is further preferably adjustable in its radial distance from the peripheral region of the rotary body. Ie. the pressure element is radially adjustable relative to the axis of rotation in its distance. Thus, the preload or pressing force with which the seal is pressed against the surface or the peripheral region of the rotary body can be adjusted or adjusted.

Conveniently, the rotary body is attached to a drive shaft extending along the axis of rotation. By rotation or rotation of the drive shaft of the rotary body is rotated in the manner described above.

In this case, the rotary body may be formed integrally with the drive shaft. Thus, a large rigidity of the rotating body and the drive shaft is generated, and the assembly is simplified.

The rotational axis surrounding further preferably on both sides of the peripheral region of the rotary body or the drive shaft shaft seals. These seals seal the high-pressure area in the area of the drive shaft to the outside. The bearings of the drive shaft are preferably outside of the shaft seals, ie outside the high pressure region in a low pressure region. The rotatable mounting of the drive shaft is preferably carried out in sliding or rolling bearings. The bearings are further preferably in the axial direction of the drive shaft of the peripheral region in which the recesses are formed, spaced, in particular so far spaced that between the bearings, a small deformation of the drive shafts is possible, so that these by the high pressure against the seal, which is located circumferentially the mouth of the abrasive supply line, is pressed.

The drive shaft is further preferably connected to a drive motor, in particular an electric drive motor, which rotatably drives the drive shaft.

Preferably, the recesses are arranged in the circumferential region of the rotating body uniformly spaced along a circumferential line. In this way, with constant rotation of the rotary body, a regular or uniform abrasive agent supply is ensured in the high-pressure region.

The depressions are further preferably formed as blind holes or blind holes in the rotary body, preferably conical

As described above, it is advantageous to introduce the abrasive mixed with water in the high-pressure region, since it is ensured that the abrasive is introduced free of air in the high-pressure region. For this purpose, the abrasive supply line can be connected to a mixing area, which is designed to mix abrasive with water. The abrasive-water mixture, ie, the suspension formed, then exits the mouth of the abrasive supply line and into the recesses in the rotating body. Particularly preferably, the rotary body via a drive, for example, an electric motor is rotatably driven, which is adjustable in its speed or clocked operable. For this purpose, a control and / or regulating device can be provided, via which the rotational speed can be adjusted. By adjusting the speed, the amount of abrasive introduced into the high pressure area per unit time can be controlled. Thus, the drive can be controlled, for example, depending on the level of abrasive in a pressure vessel and / or on and off to introduce the currently required Abrasivmittelmenge in the high pressure area. A clocked rotation is possible.

Fig. 1

schematisch den Aufbau einer erfindungsgemäßen Wasser-Abrasiv-Suspension-Schneidanlage,

Fig. 2

eine Schnittansicht einer Abrasivmittel-Zufuhreinrichtung und

Fig. 3

eine Detailansicht aus der Ansicht gemäß Fig. 2.

The invention will now be described by way of example with reference to the accompanying drawings. In these shows:

Fig. 1

1 shows the structure of a water-abrasive suspension cutting system according to the invention,

Fig. 2

a sectional view of an abrasive supply means and

Fig. 3

a detailed view from the view according to Fig. 2 ,

The water-abrasive suspension cutting device according to the invention has, in a known manner, a high-pressure pump 2, which forms a high-pressure source and is connected to a water supply 4. From the high-pressure pump 2, a high-pressure line 6 leads to a cutting or discharge nozzle 8, from which an abrasive-enriched high-pressure water jet 10 for cutting or surface treatment of a workpiece 12 emerges. On the way from the high-pressure pump 2 to the outlet nozzle 8 performs a branch of the high-pressure line 6 by an abrasive supply means 14, in which abrasive agent 16 introduced without air supply in the high pressure line 6 formed by the high pressure line and mixed in the high pressure area with the conveyed in the high pressure line pressurized water, so that it works together with the water jet 10 from the Exit nozzle 8 emerges.

In the example shown here, the unit 18, which is essentially formed by the abrasive supply device 14 and the discharge nozzle 8, is attached to a positioning system 20, which is shown here schematically as a coordinate system with which the discharge nozzle 8 relative to the workpiece 12 can be moved to produce a desired cutting path or processing history in the workpiece 12. The positioning system may be, for example, a robot or another suitable positioning system. Alternatively, however, the abrasive supply means 14 may be set up separately from the discharge nozzle 8 and connected to the movable discharge nozzle via a movable pipe or a pressure hose.

Based on Fig. 2 the exact structure of an abrasive supply means according to the invention will be described. The abrasive supply device shown has a lock, which has as a central element a rotating lock with a rotary body in the form of a spherical body 2. The ball body 22 is arranged on a drive shaft 24. In this case, the ball body 22 is formed in this embodiment in one piece with the drive shaft 24 so that the longitudinal or rotational axis D of the drive shaft 24 extends through the center of the spherical body 2. The drive shaft 24 is rotatably mounted in two bearings 26, which are spaced in the axial direction D of the spherical body 22. At an axial end of the drive shaft 24 is rotatably connected to an electric drive motor 28 which drives the drive shaft 24 and thus the ball body 22 rotating.

The spherical body 22 has a peripheral region 30 which forms the central region of the spherical body 2 in the direction of the longitudinal axis D. In this peripheral region 30, blind holes 32, which are distributed uniformly over the circumference, are introduced along the circumferential line with the largest diameter of the spherical body 2, which holes are open toward the spherical surface.

In the in Fig. 2 shown preferred installation position above the ball body 22 is an abrasive supply line 34 located below the ball body 22 and an outlet line 36 which is connected to the high-pressure line 6 and opens into this. The discharge line 36 opens into a pressure vessel 37. In the pressure vessel 37, the abrasive supplied by the abrasive supply means is stored. A part of the high-pressure line or a branch of the high-pressure line 6 leads through the pressure vessel 37 to the outlet nozzle 8, so that the water, which is passed through the pressure vessel 37, promotes the abrasive to the outlet nozzle 8.

Upstream of the abrasive agent supply line 34 is a mixing region, not shown here, in which the abrasive agent 16 is mixed with water and enters the abrasive supply line 34 as a suspension. The abrasive supply pipe 34 has an orifice 38 facing the peripheral portion 30 in which the blind holes 32 are located. In this case, the mouth 38 is located exactly opposite the circumferential line on which the blind holes 32 are arranged. This makes it possible that with a corresponding rotational position of the drive shaft 24, a blind hole 32 exactly opposite the mouth 38, so that by gravity the abrasive-water mixture can enter into the corresponding blind hole 32. The mouth 38 has for this purpose a diameter which is preferably the same size or larger than the diameter of the blind holes 32.

Surrounding the mouth is a ball seat 40 acting as a seal, which sealingly abuts the surface of the ball body 22. The ball seat 40 is formed annularly with a central opening in the region of the mouth 38. The ring has a width, which is preferably greater than the diameter of the blind holes 32, so that even when the blind holes 32 pass through the ball seat 40 and its sealing surface, no connection between the outside of the ball seat 40 and the mouth 38 are made can.

Directly below the ball body 22, the outlet line 36 has an inlet opening 42, which is opposite to the spherical body 22. When a blind hole 32, which has been filled with abrasive in the above-described manner, is turned down to be on the underside of the ball body 22, the abrasive falls out of the blind hole into the inlet 42 and the outlet 36, from where it is the high pressure line, optionally a pressure vessel in the high pressure line is supplied. By continuous rotation of the drive shaft 24 with the ball body 22 by the drive motor 28 so successively the blind holes 32 can be filled with abrasive or suspension and after rotation of the shaft, when the opening of the blind hole 32 is directed downward, down into the high pressure area , d. H. the inlet opening 42 of the outlet line 36 are emptied out. By changing the rotational speed or timing of the drive motor 28 while the amount of abrasive applied per unit time can be varied.

In order to seal the high-pressure region, to which the outlet line 36 belongs, with respect to the abrasive-medium supply line 34, the ball seat 40, which is part of a seal 44, which acts from above through a pressure element, which is designed as a screw, against the surface of the spherical body 22 is pressed. By rotation of the pressure element 46, through which the abrasive supply line 34 extends, in a thread, this can be moved in the radial direction with respect to the axis of rotation D to the surface of the spherical body 22 towards or away. As a result, the seal 44 is compressed to different degrees and thus the ball seat 40 is pressed against the surface of the ball body 22 to different degrees. Thus, the sealing system of the ball seat 40 can be adjusted. In addition, from below acts on the spherical body 22 of the prevailing in the high pressure line and thus the outlet line 36 high pressure. As a result, a pressure is exerted on the ball body 22, which presses against the ball seat 40. In order to seal the space in which the ball body 22 is located outwardly towards the bearings 26, shaft seals 48 are arranged laterally of the ball body 22 on the drive shaft 24 in the axial direction X.

The pressure vessel 37 has two level sensors 50 and 52, which detect the level with abrasive in the interior of the pressure vessel 32. The level sensors 50, 52 cooperate with a control device for the drive motor in such a way that falls below the level of the level sensor 50, which is located at the location of a minimum level, the drive motor 28 is turned on in the manner described above via abrasive to promote the discharge line 36 into the pressure vessel 37. If so much abrasive is conveyed into the pressure vessel 37 that the upper level sensor 52 is reached, a control device correspondingly turns off the drive motor 28, so that no further abrasive is conveyed into the pressure vessel 37 until the minimum level in the level sensor 50 is reached again ,

LIST OF REFERENCE NUMBERS

2

- high duck pump

4

- Water supply

6

- High pressure line

8th

- outlet nozzle

10

- high pressure water jet

12

- Workpiece

14

- abrasive supply device

16

- abrasive

18

- Unit

20

- Positioning system

22

- spherical body

24

- Drive shaft

26

- Camp

28

- Drive motor

30

- Scope area

32

- Blind holes

34

- abrasive supply line

36

- outlet pipe

37

- Pressure vessel

38

- estuary

40

- Ball seat

42

- entrance opening

44

- Poetry

46

- Pressure element

48

- shaft seals

50.52

- level sensors

D

- Rotary or longitudinal axis

Claims (14)

1. A water-abrasive suspension cutting system with a high-pressure source (2) which provides water at a high pressure, with at least one exit nozzle (8) and with a high-pressure conduit (6) which connects the high-pressure source (2) to the exit nozzle (8), wherein an abrasive agent feed device (14) connected to the high-pressure conduit (6) is provided, characterised in that
   the abrasive agent feed device (14) comprises a lock with a rotary body (22) which is rotatably driven about a rotation axis D,
   the rotary body (22) in a peripheral region (30) extending about the rotation axis D is provided with several recesses (32) which are peripherally distanced to one another, and
   that a run-out (38) of an abrasive agent feed conduit (34), and an entry opening (42) into the high-pressure conduit (6) lie opposite the peripheral region (30), in a manner such that the recesses (32) are alternately movable into a position lying opposite the run-out (38) and a position lying opposite the entry opening (42), by way of rotating the rotary body (22) about the rotation axis D.
2. A water-abrasive suspension cutting system according to claim 1, characterised in that the rotary body (22) is designed in a spherical manner.
3. A water-abrasive suspension cutting system according to claim 1 or 2, characterised in that a seal (40) which bears on the peripheral region (30) of the rotary body (22) is arranged surrounding the run-out (38) of the abrasive agent feed conduit (34).
4. A water-abrasive suspension cutting system according to claim 3, characterised in that a push element (46) which holds the seal (40) in contact on the peripheral region (30) of the rotary body (22) is arranged on the side of the seal (40) which is away from the rotary body (22).
5. A water-abrasive suspension cutting system according to claim 4, characterised in that the push element (46) is adjustable with regard to its radial distance to the peripheral region (30) of the rotary body (22).
6. A water-abrasive suspension cutting system according to one of the preceding claims, characterised in that the rotary body (22) is attached on a drive shaft (24) extending along the rotation axis D.
7. A water-abrasive suspension cutting system according to claim 6, characterised in that the rotary body (22) is designed as one piece with the drive shaft (24).
8. A water-abrasive suspension cutting system according to claim 6 or 7, characterised in that shaft seals (48) bear on the rotary body (22) or the drive shaft (24), in a manner surrounding the rotation axis D on both sides of the peripheral region (30).
9. A water-abrasive suspension cutting system according to one of the claims 6 to 8, characterised in that the drive shaft (24) is rotatably mounted.
10. A water-abrasive suspension cutting system according to one of the claims 6 to 9, characterised in that the drive shaft (24) is connected to a drive motor (28).
11. A water-abrasive suspension cutting system according to one of the preceding claims, characterised in that the recesses (32) in the peripheral region (30) of the rotary body (22) are arranged in a uniformly distanced manner along a peripheral line.
12. A water-abrasive suspension cutting system according to one of the preceding claims, characterised in that the recesses are designed as pocket holes or pocket bores (32).
13. A water-abrasive suspension cutting system according to one of the preceding claims, characterised in that the abrasive agent feed conduit (34) is connected to a mixing region designed for mixing abrasive agent with water.
14. A water-abrasive suspension cutting system according to one of the preceding claims, characterised in that the rotary body (22) is rotatably driven via a drive which in its speed can be set and can be driven in a pulsed manner.

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