CN102744507A - Plasma cutting torch nozzle - Google Patents

Abstract

The present invention relates to a plasma cutting torch, in particular to a nozzle of a plasma cutting torch, a plasma cutting torch nozzle, comprising a nozzle housing (1), and the housing includes a nozzle outer wall (1-4) whose lower part is curved ) and the inner wall of the nozzle (1-5), the shrinkage channel (1-6) connecting the outer wall of the nozzle (1-4) and the inner wall of the nozzle (1-5), sealing the outer wall of the nozzle (1-4) and the The cover plate (1-3) of the nozzle inner wall (1-5), a pair of cooling intervention inlets (1-1) and cooling medium outlets (1-2) arranged relatively on the cover plate (1-3), It is characterized in that: the plasma cutting torch nozzle also includes an annular device (2) arranged inside the inner wall (1-5) of the nozzle, and the top and bottom of the annular device (2) are respectively provided with upper edges (2-2) and the lower edge (2-3), the upper edge (2-2) and the lower edge (2-3) are respectively provided with air inlet holes (2-1) and air outlet holes (2-4). The present invention can avoid the possibility of forming double arcs between electrodes, nozzles and workpieces, has air-cooled and water-cooled nozzle structures, has good cooling effect, long service life and stable cutting performance.

Description

A plasma cutting torch nozzle

technical field

The invention relates to a plasma cutting torch, in particular to a plasma cutting torch nozzle.

Background technique

The nozzle of the plasma cutting torch is one of the main consumable parts of the cutting torch, and its life is directly related to the cutting quality and production efficiency. As shown in Figure 1, the existing common nozzles mainly use copper and copper-based materials to process the nozzles of plasma cutting torches. First, a non-transferred arc is ignited between the electrode and the nozzle. After the channel is compressed, the energy and density of the plasma arc are greatly increased. If the working current is too large, part of the arc energy will be transmitted to the wall of the nozzle hole, which will increase the temperature of the nozzle, and it is easy to form double arcs on the electrode, nozzle and workpiece, which greatly reduces the service life of the nozzle. At the same time, the interruption of the cutting process will cause Reduced cut quality and productivity.

Chinese patent document (ZL200410082549.6) discloses a detachable nozzle structure for a plasma torch, including a water supply pipe for cooling water, a drain pipe for cooling water, an annular waterway arranged around the spray hole, and the water supply pipe and The annular waterway, the drainage pipe, and the annular waterway are a plurality of connecting waterways that are independent and connected. In the nozzle for plasma welding torch described above, the cooling water supplied from the cooling water supply channel is guided into the annular water channel through the connecting water channel, and after sufficiently cooling the periphery of the spray hole of the plasma arc of the nozzle, it is passed through another connecting channel. The waterway is discharged from the cooling water distribution pipe. Even if the connecting waterway and the annular waterway are used, the cooling water can form a flow from the supply path to the discharge path, and the nozzle can be fully cooled. Although the service life of the nozzle is improved, it does not solve the problem in the electrodes and nozzles. The problem of forming a double arc with the workpiece.

Contents of the invention

The object of the present invention is to provide a nozzle of plasma cutting torch which avoids forming double arcs and has air cooling and water cooling at the same time.

In order to achieve the purpose of the above invention, the technical solution of the present invention is as follows: a plasma cutting torch nozzle, including a nozzle housing, the housing includes a nozzle outer wall and a nozzle inner wall whose lower parts are curved surfaces, and a shrinking nozzle connecting the nozzle outer wall and the nozzle inner wall. The hole, the cover plate that seals the outer wall of the nozzle and the inner wall of the nozzle, and a pair of cooling medium inlet and cooling medium outlet arranged on the cover plate; the plasma cutting torch nozzle also includes an annular device, the top and bottom of the annular device are respectively provided with an upper edge and a lower edge, and the upper edge and the lower edge are respectively provided with an air inlet hole and an air outlet hole.

Further, the axis of the air outlet hole is parallel to the tangent of the bottom curved surface of the nozzle.

Preferably, the axis of the air outlet and the axis of the ring device form an angle of 45°.

Preferably, the upper edge and the lower edge are respectively provided with no less than 3 air inlet holes and air outlet holes; 2 to 3 pairs of cooling medium inlets and cooling medium outlets can be provided on the cover plate.

Preferably, the diameters of the cooling medium inlet and the cooling medium outlet are not less than 3 mm; the height of the ring device is not less than 3 mm.

After adopting the invention, the possibility of forming double arcs between electrodes, nozzles and workpieces can be avoided, and the nozzle structure has both air cooling and water cooling, good cooling effect, long service life and stable cutting performance.

Description of drawings

Fig. 1 is the nozzle of existing common plasma cutting torch.

Fig. 2 is a three-dimensional appearance structure of the present invention.

In the figure: 1-1. Cooling medium inlet; 1-2. Cooling medium outlet; 1-3. Cover plate.

Fig. 3 is a schematic cross-sectional structure diagram of the present invention.

In the figure: 1. shell; 1-4. nozzle outer wall; 1-5. nozzle inner wall; 1-6. shrinkage channel; 2. ring device.

Fig. 4 is a structural schematic diagram of the ring device of the present invention.

In the figure: 2-1. Air inlet; 2-2. Upper edge; 2-3. Lower edge; 2-4. Air outlet.

Detailed ways

As shown in Figures 2 to 4, a plasma cutting torch nozzle includes a nozzle housing 1, and the housing includes a nozzle outer wall 1-4 and a nozzle inner wall 1-5 whose lower parts are curved surfaces, connecting the nozzle outer wall 1- 4 and the shrinkage channel 1-6 of the nozzle inner wall 1-5, the cover plate 1-3 that seals the nozzle outer wall 1-4 and the nozzle inner wall 1-5, and the 1 that is relatively arranged on the cover plate 1-3 For the cooling medium inlet 1-1 and the cooling medium outlet 1-2; the plasma cutting torch nozzle also includes an annular device 2 arranged inside the nozzle inner wall 1-5, and the top and bottom of the annular device 2 are respectively provided with upper edges 2-2 and the lower edge 2-3, the upper edge 2-2 and the lower edge 2-3 are respectively provided with an air inlet 2-1 and an air outlet 2-4.

Further, the axis of the air outlet hole 2-4 is parallel to the tangent of the bottom curved surface of the nozzle 1-5, so that the cooling gas forms a laminar flow on the inner wall 1-5 of the nozzle.

Preferably, the axis of the air outlet hole 2-4 is at 45° to the axis of the ring device 2, so that the cooling gas flows in a state of laminar flow on the inner wall 1-5 of the nozzle.

Preferably, the upper edge 2-2 and the lower edge 2-3 are respectively provided with no less than three air inlet holes 2-1 and air outlet holes 2-4; the cooling medium inlet 1 on the cover plate 1-3 -1 and cooling medium outlet 1-2 can be provided with 2 to 3 pairs. The greater the number of air inlet holes 2-1, air outlet holes 2-4, cooling medium inlet 1-1 and cooling medium outlet 1-2, the greater the processing difficulty; the fewer the number, the cooling gas forms a laminar flow on the nozzle inner wall 1-5 The worse the effect is, the less laminar flow protection will be achieved.

Preferably, the diameter of the cooling medium inlet 1-1 and the cooling medium outlet 1-2 is not less than 3mm; the height of the ring device 2 is not less than 3mm; the cooling medium inlet flow rate of 3mm diameter can make the cooling medium fill the closed space, ensuring that the nozzle The cooling effect; the height of the ring device 2 mainly considers the distance from the ring device 2 to the gas distributor, the larger the distance, the greater the amount of gas entering the ring device 2, and the better the laminar flow effect.

The working principle of the present invention is as follows: due to the generation of high-energy plasma fluid on the end face of the hafnium wire of the electrode, the heat generated will be sprayed to the inner wall 1-5 of the nozzle, especially the shrinkage channel 1-6 of the inner cavity of the nozzle, so that the inner wall of the nozzle 1-5 5 and shrinkage channel 1-6 are subjected to high temperature, and the material of the nozzle is generally copper-based material with a melting point of about 1356K, while the temperature of the plasma arc is above 5000K, so it is difficult for the copper-based nozzle to withstand such a high plasma Therefore, it is necessary to have a forced cooling medium to cool the copper-based nozzle so that its temperature drops below the melting point of the copper-based. For the cooling structure of ordinary air-cooled nozzles, when the working current is not very large, for example, the working current below 40A-100A, the energy density of the arc is not very high, and the nozzle can work only with gas cooling. When the operating current exceeds 100A, the nozzle inner wall 1-5 and the shrinkage channel 1-6 need to be cooled to ensure that it is not easy to form a double arc between the electrode, the nozzle and the workpiece. Since the double arc quickly burns the nozzle and scraps it, water-cooled nozzles are usually used at this time. However, when the working current is large, only the cooling structure of the water-cooled nozzle cannot meet the high energy density of the arc fluid temperature. It is necessary to improve the cooling structure to prolong the service life of the nozzle to ensure normal plasma cutting. Work.

As shown in Figure 3, the nozzle of the present invention has an additional annular device 2 on the basis of the existing common water-cooled nozzle, the upper edge 2-2 of the annular device 2 is provided with an air inlet 2-1, and the gas passes through the air inlet 2- 1 Enter the space formed by the ring device 2 and the nozzle inner wall 1-5, the lower edge 2-3 of the ring device 2 is provided with an air outlet 2-4, the axis of the centerline air outlet 2-4 is in line with the curved surface of the nozzle inner wall bottom The tangents are parallel, and the gas flowing out from the air outlet hole 2-4 can cool the inner wall 1-5 of the nozzle and the wall surface of the shrinkage channel 1-6. The cooling medium is passed through the annular channel between the inner wall 1-5 of the nozzle and the outer wall 1-4 of the nozzle, and an annular device is added in the inner wall 1-5 of the nozzle, so that the ion gas is divided into two paths, and one path passes between the annular device 2 and the electrode. The space between forms the plasma gas; the other path enters the space formed by the annular device 2 and the nozzle inner wall 1-5 through the air inlet 2-1 on the upper edge 2-2 of the annular device 2. Due to the increase of the gas volume, the pressure decreases, and then it is output from the shrinkage channel 1-6 below the annular device 2 . Because the output velocity of this airflow is very small, thereby the Reynolds number is small, forming a laminar flow along the nozzle inner wall 1-5 at the nozzle inner wall 1-5. An isolation layer is formed at the shrinkage channel 1-6, which isolates the plasma arc from the surface of the shrinkage channel 1-6, thereby prolonging the life of the nozzle, and also has the advantages of good cutting quality and high work efficiency.

Claims (5)

1. plasma cutting-torch nozzle; Comprise nozzle body (1); Said housing comprise the bottom be nozzle outer wall (1-4) and the nozzle inner walls (1-5) of curved surface, be connected shrinkage cavity road (1-6), sealing said nozzle outer wall (1-4) and the said nozzle inner walls (1-5) of said nozzle outer wall (1-4) and nozzle inner walls (1-5) cover plate (1-3), be oppositely disposed in that 1 couple cooling on the said cover plate (1-3) gets involved inlet (1-1) and cooling medium exports (1-2); It is characterized in that: said plasma cutting-torch nozzle also comprises the ring device (2) that is arranged on nozzle inner walls (1-5) inside; The top of said ring device (2) and bottom are respectively equipped with top edge (2-2) and lower limb (2-3), and said top edge (2-2) and lower limb (2-3) are respectively equipped with air admission hole (2-1) and venthole (2-4).

2. a kind of plasma cutting-torch nozzle according to claim 1 is characterized in that the axis of said venthole (2-4) and the tangent line of said nozzle (1-5) bottom curved surface parallel.

3. a kind of plasma cutting-torch nozzle according to claim 1 is characterized in that the axis of said venthole (2-4) and the axis of ring device (2) are 45 °.

4. according to claim 1 or 2 or 3 described a kind of plasma cutting-torch nozzles, it is characterized in that said top edge (2-2) and lower limb (2-3) are respectively equipped with and be no less than 3 air admission holes (2-1) and venthole (2-4); Cooling on the said cover plate (1-3) gets involved inlet (1-1) and cooling medium outlet (1-2) can be provided with 2～3 pairs.

5. a kind of plasma cutting-torch nozzle according to claim 4 is characterized in that the diameter of said cooling intervention inlet (1-1) and cooling medium outlet (1-2) is not less than 3mm; The height of said ring device (2) is not less than 3mm.

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