Nozzle for cutting steel workpieces

Abstract

The invention relates to a nozzle (1) for cutting steel workpieces and workpieces made of iron alloys, comprising a nozzle body (2), wherein the nozzle body (2) has two cutting-oxygen bores (5, 5a), which extend from an inlet side (6) of the nozzle body (2) to an outlet side (8) of the nozzle body (2) in order to form two cutting jets (10, 10a). The double cutting flame cuts the steel more strongly in the so-called groove trail. The cut is thus more effective. This permits an increased cutting speed, which in turn causes a reduction in the heating-gas consumption.

Claims

1. Nozzle for cutting steel workpieces and workpieces made of ferrous alloys with: a) a nozzle body; b) wherein the nozzle body has at least two cutting oxygen bores, which extend from an inlet side of the nozzle body towards an outlet side of the nozzle body to form at least two cutting jets; c) wherein the nozzle body has a free space, which is bounded by the outlet side and into which the cutting oxygen bores open; and with d) a plurality of heating oxygen bores and heating gas bores, which are arranged in concentric circles around the two cutting oxygen bores; and with e) an inner annular groove formed in the wall of the free space, the groove including an outlet-side wall which is at an angle of 45° with respect to the centre axis of the nozzle, and into which the heating oxygen bores open.

2. Nozzle according to claim 1, characterised in that the two cutting oxygen bores are funnel-shaped and open at an angle of 6 to 8° at the outlet side.

3. Nozzle according to claim 1, characterised in that the inlet side has a recess from which the two cutting oxygen bores extend.

4. Nozzle according to claim 3, characterised in that the recess has a diameter of at least 6 mm.

5. Nozzle according to claim 1, characterised in that the diameter of the inlet openings of the two cutting oxygen bores is 2.75 mm.

6. Nozzle according to any of claims 1-5, characterised in that the diameter of the outlet openings of the two cutting oxygen bores is 4.5 mm.

7. Nozzle according to claim 1, characterised in that the free space is concavely cup-shaped.

8. Nozzle according to claim 7, characterised in that the nozzle body is partially surrounded peripherally by a hexagonal nut for screwing the nozzle onto a cutting torch; and the cup-shaped free space and the hexagonal nut are integrally formed.

9. Nozzle according to claim 7, characterised in that the bottom of the cup-shaped free space is concavely conical.

10. Nozzle according to claim 9, characterised in that a cone angle of the cup-shaped free space is 116° to 118°.

11. Nozzle according to claim 1, characterised in that a connecting channel is formed between a heating oxygen bore and a heating gas bore; wherein the connecting channel has a diameter of 0.8 to 1.2 mm and is at an angle of 45° to the centre axis of the nozzle, extending in such a way from the heating gas bore to the heating oxygen bore that heating gas passes from the heating gas bore to the heating oxygen bore in a metered fashion.

12. Nozzle according to claim 1, characterised in that the free space opens towards the outlet side with an opening angle of 6.5 to 7.5°.

Description

(1) The embodiments are shown schematically in the figures. The same reference numerals in the individual figures denote identical elements or elements that are functionally identical in terms of their functions. Specifically:

(2) FIG. 1 shows an outlet-side end view of a first embodiment of the nozzle;

(3) FIG. 2 shows a sectional view of the first embodiment of the nozzle taken along line A-A in FIG. 1;

(4) FIG. 3 shows an inlet-side end view of the nozzle of the first embodiment shown in FIG. 1;

(5) FIG. 4 shows an outlet-side end view of a second embodiment of the nozzle;

(6) FIG. 5 shows a sectional view of the second embodiment of the nozzle taken along line B-B in FIG. 4;

(7) FIG. 6 shows an inlet-side end view of the nozzle of the second embodiment shown in FIG. 4; and

(8) FIG. 7 shows a sectional view of the second embodiment of the nozzle taken along line A-A in FIG. 6.

FIRST EMBODIMENT

(9) The nozzle 1 according to FIGS. 1 to 3 has an integrally-formed nozzle body 2. The nozzle body 2 is partially provided peripherally with a hexagonal nut 3 in order to attach this to a cutting torch (not shown) by means of an appropriate tool. Another section of the outer periphery of the nozzle body 2 is provided with an outer thread 4, in order to screw the nozzle 1 on a cutting torch.

(10) The nozzle body 2 has a diameter of typically 30 mm and a height of typically 35 mm and is integrally formed from copper.

(11) Two axial bores 5, 5a for the cutting oxygen are formed at the centre of the nozzle body 2, and extend from the inlet side 6 to a cup-shaped cylindrical space 7 on the outlet side 8 of the nozzle body 2. The outlet side 8 and the cup-shaped cylindrical free space 7 are directly defined and limited by the hexagonal nut 3. The cup-shaped cylindrical free space 7 typically has a depth of 10 mm and a diameter of 20 mm.

(12) The inlet side 6 has a recess 12 out of which two cutting oxygen bores 5, 5a extend. The recess 12 has a diameter of 6 mm and a depth of typically 3-5 mm. There is an impact loss of the cutting oxygen upon entering the axial bores 5, 5a. This impact loss decreases the pressure, wherein the velocity of the gas is increased according to the Bernoulli principle in order to increase efficiency on cutting the steel.

(13) The diameter of the inlet openings of the two cutting oxygen bores 5, 5a is 2.7 to 2.75 mm. There is a substantially parallel throat 14 adjoining the inlet openings of each of the axial bores 5, 5a. The throat leads to another pressure loss and thus to a further increase in the speed of the cutting oxygen.

(14) Following the throat, the two axial bores 5, 5a have a funnel-shaped or conical expansion 9 at the end facing the cup-shaped cylindrical space 7 by means of which the cutting oxygen flowing through the axial bores 5, 5a is accelerated. The conical expansions open at an angle of 6 to 8°, preferably 7°, at the outlet side.

(15) The diameter of the outlet openings of the two cutting oxygen bores 5, 5a is 4.5 mm. The cutting jets 10, 10a are formed at the outlet end of the axial bores 5, 5a as shown in FIG. 2.

(16) The part of the outlet side 8 lying within the cup-shaped cylindrical free space 7 is concavely conically shaped, wherein the cone angle is 118°. In addition, a step 16 is formed at the outlet end of the cup-shaped cylindrical free space 7. The step 16 typically has a depth of 3-5 mm and a width of 1.5-2 mm. The expanding gases bounce off this step to become more focused and prevent slag deposits on the wall of the cup-shaped cylindrical free space 7.

(17) The nozzle 1 comprises a plurality of, typically sixteen, heating oxygen bores 11 which are arranged in an outer concentric circle around the axial bore 5, 5a and not quite parallel to the axial bores 5, 5a and extending from the inlet side 6 of the nozzle 1 to the cup-shaped cylindrical free space 7 of the nozzle body 2. The heating oxygen bores 11 are arranged in an annular channel 18 which is delimited by an outer sealing ring 20 and a central sealing ring 22. The annular channel 18 for the heating oxygen has a width of typically 2.5 mm and a depth of 0.8 mm with respect to the sealing rings ending in a common plane. The sealing rings have a width of typically 1 mm.

(18) Furthermore, a plurality of, typically eight, heating gas bores 13 are arranged in an inner concentric circle around the axial bore and are likewise not quite parallel to the axial bores 5, 5a extending from the inlet side 6 of the nozzle 1 to the cup-shaped cylindrical free space 7 of the nozzle body 2. The heating gas bores 13 are arranged in an annular channel 24 which is delimited by the central sealing ring 22 and an inner sealing ring 26. The annular channel 24 for the heating gas likewise has a width of typically 2.5 mm and a depth of 0.8 mm with respect to the sealing rings ending in a common plane. The elevated sealing rings form a gasket and are pressed against a correspondingly configured flat gas supply.

(19) Each of the bores, namely the axial bores 5, 5a, the heating gas bores 13 and the heating oxygen bores 11 open into the cylindrical free space 7 in which the cutting jets are formed.

SECOND EMBODIMENT

(20) FIGS. 4 to 7 show a second embodiment of the nozzle 1. The matching elements of the nozzle 1 in the two embodiments are identified with identical reference numerals and will not be described again. Only the differences between the two embodiments will be described.

(21) FIG. 5 shows the main innovations of the second embodiment.

(22) On the one hand, a connecting channel 28 can be seen in FIG. 5, which runs between the heating oxygen bore 11 and the heating gas bore 13. The connecting passage has a diameter of 1 mm and extends at an angle of 45° in the direction of the flow from the heating gas bore 13 to the heating oxygen bore 11. The heating gas passes through the connecting channel 28 from the heating gas bore 13 into the heating oxygen bore 11 in a metered fashion.

(23) In this second embodiment, the heating oxygen bore 11 opens into an inner annular groove 30 formed in the wall of the free space 7, wherein the outlet-side wall forms an angle of 45° with respect to the centre axis of the nozzle 1. The inner annular groove 30 directs the heated mixture at an angle of typically 45° inwards into the free space 7. As a result, the heated mixture flows uniformly around the trailing edges of the nozzle body 2. This leads to a significant reduction in noise.

(24) Furthermore, it can be seen in FIG. 5 that the free space 7 opens to the outlet side 8 at an opening angle of 6.5 to 7.5°. In preferred embodiments of FIG. 5, the opening angle is 6.5° corresponding to 3.25° respectively on all sides.

REFERENCE NUMERALS

(25) 1 Nozzle 2 Nozzle body 3 Hexagonal nut 4 External thread 5 First axial bore 5a Second axial bore 6 Inlet side 7 Free space 8 Outlet side 9 Conical expansion 10 Cutting jet 10a Cutting jet 11 Heating oxygen bores 12 Recess 13 Heating gas bores 14 Throat 16 Step 18 Annular channel 20 Outer sealing ring 22 Central sealing ring 24 Annular channel 26 Inner sealing ring 28 Connecting channel 30 Inner annular groove