EP0873220B1 - Modular abrasive medium water jet cutting head - Google Patents

Abstract

PCT No. PCT/DE97/02290 Sec. 371 Date Jun. 4, 1998 Sec. 102(e) Date Jun. 4, 1998 PCT Filed Oct. 4, 1997 PCT Pub. No. WO98/15385 PCT Pub. Date Apr. 16, 1998A modular abrasive agent water jet cutting head (1) has a nozzle (4) issuing a high-speed water jet (16), a mixing chamber (10) through which the high speed water jet passes (16), an abrasive agent supply line (14), and a focussing nozzle (15) forming the outlet of the mixing chamber (10). A dosing unit (12) has an axial passage of the high-speed water jet (16). The passage (18) has one or more expansions or channels (11) extending radially and which are of reduced cross section at the passage. There are preferably in each case are formed as a slits, which are only slightly wider than the diameter of the thickest abrasive particle. The expansion or channel (11) is closely connected to the passage of the high-speed water jet (16) and introduces the abrasive agent into a chordal section of the water jet (16) which is oriented in the direction of the cutting action. From there the high-speed water jet (16) receives a track of abrasive agent on its surface.

Description

The invention relates to a modular abrasive water jet cutting head with targeted addition of abrasive (see e.g. DE-A-4 313 704).

It is known to use an abrasive in the cutting water jet Mix grenade or corundum to achieve the cutting action of the Enlarge cutting water jet. This is the abrasive in a mixing chamber through which the water jet flows vertically is, the water jet from the side as possible on the entire circumference fed evenly (EP 221236).

To prevent scouring in the mixing chamber by the abrasive avoid it is known to do this through deposited abrasive to protect (DEOS 3844344), so that the abrasive by Wash water directly into the water jet becomes. To reinforce this, the abrasive is accelerated at an acute angle (GM 9402936.9) and under Pressure (DE-OS 4005691) placed in the mixing chamber.

To the focusing nozzle before the action of the abrasive protect, the cutting jet is covered with a water jacket (DE-OS 4005691). For better mixing of the abrasive in the water jet is known, the focusing nozzle is funnel-shaped to expand on the inlet side (EP 110529).

According to OS-DE 3516103 is a uniform with abrasive particles loaded cutting beam condition for a clean, uniform cut. With unilateral, uneven distribution the particles in the mixing chamber and therefore the untargeted ones Particle supply to the circumference of the central flowing through the mixing chamber Water jet of the cutting heads described above results no uniform particle beam as desired is. An asymmetrically loaded mixed jet can be an uneven one Cut and one-sided wear of the focusing nozzle cause.

Exact investigations have shown that only those on the surface abrasive particles located in the cutting direction of the mixed jet bring a cutting performance. The inside of the Cutting beam or on the side facing away from the cutting direction abrasive particles in the jet do not bring any Cutting performance.

Purpose and object of the invention is to the surface of the Cutting jet in the respective cutting direction abrasive particles to reduce cutting performance increase the use of abrasives.

According to the invention, the object is characterized by the characteristic features of the 1st claim solved. Advantageous designs the invention are the subject of the dependent claims.

The realization that only those on the surface of the cutting beam effective abrasive particles in the cutting direction be leads to the fact that the previously known mixing chamber with a Dosing insert is filled, the bore of which runs through the Cutting beam is to which an expansion nestles laterally. From this expansion, there will be a relationship of the diameter of the abrasive particles to that of the cutting jet of about 1: 4 on the surface of the cutting beam in one Traces of 30 ° to 60 ° wide abrasive particles applied. By a rotation of the controlled according to the cutting parameters Cutting head or the dosing insert around the axis of the cutting beam there occurs the exit of the coated with abrasive Trace out of the focusing nozzle at the cutting direction Side of the cutting beam. By using a dosing insert with several widenings evenly distributed around the cutting beam for feeding the abrasive particles, each of which only the expansion (s) approximately in the cutting direction is / are loaded with abrasive particles, the angle of rotation for the cutting head is reduced or the cutting head is rigidly fastened become. In the modular abrasive water jet cutting head there is an adjustment element with which individually and / or completely to ensure the alignment of the beam guiding elements and thus to ensure a collimation of the beam-forming Head components an adjustment of these parts takes place.

Fig. 1

einen Längsschnitt durch einen modularen Schneidkopf im Prinzip

Fig. 2

einen Dosiereinsatz im Längsschnitt

Fig. 3

einen Dosiereinsatz im Querschnitt

The invention will be explained in more detail below using an exemplary embodiment. The associated drawing shows in

Fig. 1

a longitudinal section through a modular cutting head in principle

Fig. 2

a dosing insert in longitudinal section

Fig. 3

a dosing insert in cross section

A modular cutting head 1 is attached to a collimation tube 2 a high pressure connection 3 connected. Before the end of the collimation tube 2 is a nozzle block 4. Starting from nozzle block 4 runs through the entire modular cutting head 1 whose central axis 5 is a central channel 6. The modular cutting head 1 is encased by a housing 7, which with a focusing nozzle holder 8 is completed. The 9 screws modular cutting head 1 supported.

In the interior of the housing 7 there is a mixing chamber 10, the one with a widening 11 metering insert 12th contains. With a spacer 13, the dosing insert 12 positioned in the mixing chamber 10. Opens into the mixing chamber 10 an abrasive feed line on the side 14. Before the abrasive feed line 14 is the widening 11. To the mixing chamber 10 closes in the axial direction of the modular cutting head 1 a focusing nozzle 15 held by the focusing nozzle holder 8 on. A high-speed water jet generated by the nozzle block 4 16 flows in the axial direction along the central axis 5 the modular cutting head 1 in the central channel 6. In the dosing insert 12 is on a jacket section of the high-speed water jet 16 applied a trace of abrasive. To there is a bore 18 in the middle of the dosing insert 12, which is fixed by means of a groove 17. The bore 18 has one approximately the strength of the high speed water jet 16 corresponding diameter. The wall of the bore 18 is through the expansion 11 cut open. The abrasive is only on the jacket section of the High speed water jet 16 applied. The modular Cutting head 1 is rotated during cutting so that the Focusing nozzle 15 always the trace of the abrasive on the in Cutting direction of the side of the high-speed water jet 16 exits.

List of the reference symbols used:

1

cutting head

2

collimation

3

High-pressure connection

4

nozzle block

5

central axis

6

Central channel

7

casing

8th

Fokussierdüsenhalter

9

screw

10

mixing chamber

11

widening

12

proportioning

13

spacer

14

Abrasivmittelzuleitung

15

focusing nozzle

16

Hochgeschindigkeitswasserstrahl

17

groove

18

drilling

Claims (10)

1. Modular abrasive agent water jet cutting head (1) with a nozzle (4) issuing a high-speed water jet (16), a mixing chamber (10) through which the high-speed water jet (16) passes, an abrasive agent supply line (14) and a focussing nozzle (15) forming the outlet of the mixing chamber (10), wherein a dosing unit (12) with a hole (18) for receiving the high-speed water jet (16) is located in the mixing chamber (10), the hole (18) of which has an expansion (11) laterally, which is joined closely with the passage for the high-speed water jet (16) and from which a track of abrasive agent emerging on the focussing nozzle (15) on the side of the high-speed water jet (16) located in the cutting direction is given.
2. Modular abrasive agent water jet cutting head (1 ) in accordance with Claim 1, wherein the expansion (11) is narrowed to a slit, which is only slightly wider than the diameter of the thickest particle of abrasive agent.
3. Modular abrasive agent water jet cutting head (1) in accordance with Claim 1, wherein the cutting head (1) can be turned around the axis of the high-speed water jet (16).
4. Modular abrasive agent water jet cutting head (1) in accordance with Claim 1, wherein the dosing unit ( 12) can be rotated around the axis of the high-speed water jet (16).
5. Modular abrasive agent water jet cutting head (1) in accordance with Claim 1, wherein the dosing unit (12) has several expansion (11) distributed around the passage of the high- speed water jet (16), of which expansions in each case only one is charged with abrasive agent in a controlled fashion.
6. Modular abrasive agent water jet cutting head (1 ) in accordance with Claims 1 and 5, wherein in the dosing unit (12) alternatively only one expansion located approximately in the direction of cutting is opened in a controlled fashion.
7. Modular abrasive agent water jet cutting head (1 ) in accordance with Claims 1 and 5, wherein several expansions in the dosing unit (12), located approximately in the cutting direction, are opened individually in sequence or simultaneously.
8. Modular abrasive water jet cutting head (1 ) in accordance with Claim 1, wherein a vibration source is connected to the dosing unit (12).
9. Modular abrasive agent water jet cutting head ( 1 ) in accordance with Claim 1, wherein a guide groove corresponding with the expansion (11) in the dosing unit (12) is located in the focussing nozzle (15).
10. Modular abrasive agent water jet cutting head (1) in accordance with Claim 1, wherein it contains an adjusting element for aligning the jet-guiding elements.

Images