CN109093236B

CN109093236B - Plasma cutting method and plasma cutting machine

Info

Publication number: CN109093236B
Application number: CN201811299838.XA
Authority: CN
Inventors: 请求不公布姓名
Original assignee: Hugong Intelligent Technology Suzhou Co ltd; Shanghai Acetylene Welder Factory Co ltd
Current assignee: Hugong Intelligent Technology Suzhou Co ltd; Shanghai Acetylene Welder Factory Co ltd
Priority date: 2018-11-02
Filing date: 2018-11-02
Publication date: 2023-03-28
Anticipated expiration: 2038-11-02
Also published as: CN109093236A

Abstract

The invention discloses a plasma cutting method and a plasma cutting machine, and relates to the technical field of plasma cutting. The plasma cutting method comprises the following steps: when the cutting gun stretches into the underwater cutting, compressed air is injected into the water, so that the volume concentration of hydrogen on the water surface is smaller than the designated concentration. In the plasma cutting method, the concentration of hydrogen on the water surface can be reduced by injecting compressed air into water, and hydrogen combustion is avoided, so that water surface combustion is avoided.

Description

Plasma cutting method and plasma cutting machine

Technical Field

The invention relates to the technical field of plasma cutting, in particular to a plasma cutting method and a plasma cutting machine.

Background

As shown in fig. 1, when the plasma cutting machine performs underwater cutting, the cutting torch 1 'extends into the water tank 2' to cut the workpiece 3 ', and water near the cutting torch 1' is electrolyzed to generate a certain amount of hydrogen and oxygen. When the hydrogen and the oxygen overflow from the water surface, the volume concentration of the hydrogen near the water surface is increased, and the water surface can generate the combustion phenomenon of the hydrogen after meeting sparks generated by cutting.

Disclosure of Invention

One object of the present invention is to provide a plasma cutting method that can avoid hydrogen combustion on the water surface.

In order to achieve the purpose, the invention adopts the following technical scheme:

a plasma cutting method comprising the steps of:

when the cutting gun stretches into the underwater cutting, compressed air is injected into the water, so that the volume concentration of hydrogen on the water surface is smaller than the designated concentration.

Wherein the compressed air is distributed with the cutting gun as a center.

Wherein the specified concentration is 4%.

And when the cutting gun is positioned on the water surface for a specified distance, blowing air to the water surface below the cutting gun.

Wherein the specified distance is 3-5cm.

Another object of the present invention is to provide a plasma cutting machine capable of preventing hydrogen from burning on the water surface.

a plasma cutting machine comprising a cutting gun, the plasma cutting machine further comprising:

a first nozzle connected with the cutting gun; and

and the air supply device is connected with the first nozzle and used for providing compressed air.

Wherein the first nozzle is an annular nozzle, and the annular nozzle is arranged coaxially with the cutting gun.

Wherein, the plasma cutting machine further comprises:

the adjusting part, the adjusting part respectively with annular nozzle with the cutting torch is connected, the adjusting part can adjust annular nozzle with the relative position of cutting torch, so that annular nozzle with the coaxial setting of cutting torch.

Wherein the adjustment assembly comprises:

one end of the first connecting piece is connected with the annular nozzle, and the other end of the first connecting piece is provided with a waist-shaped hole which extends along the radial direction of the cutting gun;

the cutting gun is provided with an installation frame, and a bolt penetrates through the waist-shaped hole and the installation frame and then is connected with a nut.

Wherein, the plasma cutting machine further comprises:

first gas supply line, first gas supply line respectively with annular nozzle with air feeder intercommunication, first gas supply line with the cutting torch is connected.

The first connecting piece is clamped and fixed on the first gas supply pipeline, and the first gas supply pipeline can rotate and slide up and down relative to the first connecting piece.

Wherein, be provided with first ooff valve and first flow valve on the first air supply line.

Wherein, the plasma cutting machine further comprises:

the second nozzle, the second nozzle set up in cutting gun one side, just the second nozzle orientation the below of cutting gun sets up, the second nozzle with the air feeder intercommunication.

Wherein, the plasma cutting machine further comprises:

and the second gas supply pipeline is communicated with the second nozzle and the gas supply device respectively.

And a second switching valve and a second flow valve are arranged on the second gas supply pipeline.

Wherein, the plasma cutting machine further comprises:

a detection assembly for detecting the distance of the end of the cutting gun from the water surface; and

the controller, the controller with the detection component electricity is connected, is used for control the air feeder to first nozzle with the air feed of second nozzle.

Has the advantages that: the invention provides a plasma cutting method and a plasma cutting machine. In the plasma cutting method, the concentration of hydrogen on the water surface can be reduced by injecting compressed air into water, and hydrogen combustion is avoided, so that water surface combustion is avoided.

Drawings

FIG. 1 is a schematic diagram of a prior art plasma cutter;

FIG. 2 is a schematic structural view of the plasma cutting machine provided by the present invention, without showing the machine body and the controller;

fig. 3 is a schematic structural view of the plasma cutting machine provided by the present invention, without showing the machine body, the cutting gun and the mounting bracket.

Wherein:

1. cutting the torch; 2. a first nozzle; 21. spraying a hole; 3. a second nozzle; 4. a mounting frame; 5. a first gas supply duct; 51. a first on-off valve; 52. a first flow valve; 6. a second gas supply duct; 61. a second on-off valve; 62. a second flow valve; 7. a gas supply device; 81. a first connecting member; 811. a waist-shaped hole; 82. a first bolt; 83. a second connecting member; 9. a controller;

1', a cutting gun; 2', a water tank; 3', and a workpiece.

Detailed Description

In order to make the technical problems solved, the technical solutions adopted and the technical effects achieved by the present invention clearer, the technical solutions of the present invention are further described below by way of specific embodiments with reference to the accompanying drawings.

The embodiment provides a plasma cutting method which can be suitable for high-power plasma underwater cutting. When the plasma underwater cutting is carried out, the cutting gun extends below the water surface, so that smoke dust and arc light generated by cutting can be completely absorbed by water.

During cutting, water near the cutting gun is electrolyzed to generate a certain amount of hydrogen and oxygen. When the hydrogen and the oxygen overflow from the water surface, the concentration of the hydrogen near the water surface is increased, and the hydrogen is burnt on the water surface after encountering sparks generated by cutting, so that the cutting effect is influenced.

In order to solve the above problem, in the plasma cutting method provided in this embodiment, compressed air is injected into water while the cutting gun is inserted into the water for cutting, and the compressed air and hydrogen generated by electrolysis overflow the water surface together. Due to the dilution effect of the compressed air, the volume concentration of the hydrogen on the water surface can be reduced to be below the specified concentration. Wherein the designated concentration is the critical concentration of hydrogen gas burning in fire. In this embodiment, the specified concentration may be 4%. By reducing the volume concentration of hydrogen below the critical concentration, the phenomenon of hydrogen burning on the water surface can be avoided.

For better dilution of the hydrogen concentration, the compressed air can be distributed around the axis of the cutting gun, so that the compressed air is uniformly distributed on the cutting gun accessory, and the hydrogen concentration is better diluted.

When the cutting gun cuts workpieces such as steel plates, granular scum can be generated and is suspended on the water surface, and the scum can easily enter a nozzle of the cutting gun, so that the cutting gun is damaged, the normal use and the service life of the cutting gun are influenced, and the plasma cutting cost is improved.

In order to avoid the dross to enter into the cutting torch, when the cutting torch removed the appointed distance to the surface of water, blown on through the surface of water to the cutting torch below for the dross is kept away from the cutting torch, avoids the dross to stretch into in the in-process entering cutting torch under the surface of water at the cutting torch, thereby prevents that the cutting torch from blockking up impairedly, guarantees cutting torch's normal use and life-span.

Optionally, the specified distance may be determined according to actual needs, and in this embodiment, the specified distance is selected to be 3-5cm, for example, 3cm, 3.5cm, 4cm, 4.5cm, and 5cm.

The embodiment also provides a plasma cutting machine, which can be applied to the underwater plasma cutting technology and can avoid the problem of hydrogen water surface combustion.

As shown in fig. 2, the plasma cutting machine includes a machine body and a cutting torch 1 disposed on the machine body, and the cutting torch 1 can move up and down and horizontally relative to the machine body, so that the cutting torch 1 cuts a workpiece according to a preset trajectory. Specifically, be provided with lifting unit, translation subassembly and mounting bracket 4 on the organism, cutting torch 1 installs on mounting bracket 4, and lifting unit and translation subassembly are connected with mounting bracket 4 for drive mounting bracket 4 removes, thereby drive 1 lift of cutting torch or translation.

When the plasma cutting machine works, a workpiece to be cut is placed in the water tank, and the lifting assembly drives the mounting frame 4 to move downwards, so that the end part of the cutting gun 1 extends into the position below the water surface. Then, the translation assembly drives the cutting gun 1 to move in the horizontal direction so as to cut the workpiece.

In the cutting process, water near the cutting torch 1 is electrolyzed to generate hydrogen and oxygen. After the hydrogen overflows the water surface, the hydrogen concentration on the water surface is obviously increased. Due to the characteristic that hydrogen is extremely easy to burn, the hydrogen burns after contacting sparks generated when the hydrogen is cut by the cutting gun 1, the phenomenon of burning on the water surface occurs, normal cutting is influenced, and the safety of equipment and workers is damaged.

In order to avoid the problem of water surface burning, the plasma cutting machine further comprises a first nozzle 2 and a gas supply device 7. The first nozzle 2 is connected to the cutting torch 1 and is located near the end of the cutting torch 1. The first nozzles 2 are in communication with an air supply 7, which air supply 7 can supply compressed air to the first nozzles 2. When the cutting gun 1 is extended below the water surface, the first nozzle 2 is also located below the water surface. When the cutting gun 1 is used for cutting, the first nozzle 2 injects compressed air into water, and the atomized compressed air disturbs the water and overflows the water surface together with hydrogen and oxygen generated by water electrolysis. Compressed air dilutes the volume concentration of hydrogen above the water surface, and the volume concentration of hydrogen can be controlled to be at the critical concentration of burning in fire by controlling the flow of the compressed air, so that the hydrogen burning on the water surface is avoided, and the normal work of the plasma cutting machine is ensured.

In order to better dilute the concentration of hydrogen and avoid hydrogen combustion, the first nozzle 2 can be an annular nozzle, and the cutting torch 1 is arranged in the annular nozzle in a penetrating manner, and the annular nozzle and the cutting torch 1 are coaxially arranged. Evenly be provided with a plurality of openings orifice 21 down along circumference on the annular nozzle to inject compressed gas around to cutting gun 1 uniformly, make the hydrogen concentration of near cutting gun 1 near each department of surface of water top dilute evenly, avoid appearing the problem of local hydrogen burning.

The annular nozzle and the cutting gun 1 are coaxially arranged, and the opening of the spray hole 21 faces downwards, so that the injected compressed air can be prevented from influencing the normal cutting of the cutting gun 1.

As shown in fig. 2 and 3, the plasma cutting machine further includes a first gas supply duct 5, and the first gas supply duct 5 may be vertically disposed, and has an upper end communicating with the gas supply device 7 and a lower end communicating with the annular nozzle through an elbow so as to supply gas into the annular nozzle.

In order to ensure that the annular nozzle and the cutting gun 1 are coaxially arranged, the plasma cutting machine further comprises an adjusting assembly, and the adjusting assembly can adjust the relative positions of the annular nozzle and the cutting gun 1 so as to ensure that the annular nozzle and the cutting gun 1 are coaxially arranged.

Specifically, the adjusting assembly includes a first connecting member 81, one end of the first connecting member 81 is connected to the first gas supply duct 5, the other end is provided with a waist-shaped hole 811, a connecting hole is provided on the mounting bracket 4, and a first bolt 82 passes through the waist-shaped hole 811 and the connecting hole and then is screwed with a first nut, thereby connecting the first connecting member 81 to the mounting bracket 4. By adjusting the position of the first bolt 82 in the kidney hole 811, the relative position of the annular nozzle and the cutting gun 1 can be adjusted. In this embodiment, the waist-shaped hole 811 extends along the radial direction of the cutting torch 1, and when the position of the first bolt 82 in the waist-shaped hole 811 changes, the distance between the inner side of the annular nozzle and the axis of the cutting torch 1 can be adjusted.

In this embodiment, the first connecting member 81 and the first air supply duct 5 are fixed in a clamping manner, and the connecting position of the first connecting member 81 and the first air supply duct 5 can also be adjusted. Specifically, the first connecting part 81 is provided with a first clamping hole, the diameter of the first clamping hole is slightly smaller than the diameter of the first air supply pipeline 5, the first clamping hole extends to the end of the first connecting part 81 along the radial direction to form a notch, and two opposite sides of the notch are respectively provided with a through hole. When the first connecting piece 81 is connected with the first gas supply pipeline 5, the first gas supply pipeline 5 penetrates through the first clamping hole, and the second bolt sequentially penetrates through the two through holes and then is screwed and fixed with the second nut, so that the first gas supply pipeline 5 is clamped and fixed in the first clamping hole, and the first gas supply pipeline 5 and the first connecting piece 81 are fixed.

Before the first air supply duct 5 is clamped and fixed, the position of the annular nozzle can be adjusted by rotating the first air supply duct 5 so that the axis of the annular nozzle and the central axis of the kidney-shaped hole 811 are located in the same vertical plane. Since the waist-shaped hole 811 extends along the radial direction of the cutting gun 1, the connection line of the center of the annular nozzle and the axis of the cutting gun 1 in the horizontal direction can be ensured to be consistent with the extending direction of the waist-shaped hole 811, and then the annular nozzle and the cutting gun 1 can be ensured to be coaxial only by adjusting the position of the first bolt 82 in the waist-shaped hole 811.

In addition, the first air supply pipeline 5 is clamped and fixed, and the first air supply pipeline 5 can also slide up and down relative to the first connecting piece 81, so that the distance between the annular nozzle and the end part of the cutting gun 1 is adjusted, and the injection depth of compressed air under water is adjusted.

In order to control the opening and closing of the annular nozzle and the flow rate of the compressed air conveniently, a first switch valve 51 and a first flow valve 52 may be further disposed on the first air supply pipeline 5. The first on-off valve 51 is used to control the opening and closing of the first air supply duct 5, and the first flow valve 52 is used to control the flow rate of the compressed air supplied from the annular nozzle.

In order to prevent scum generated during cutting from entering the cutting torch 1, the plasma cutting machine is further provided with a second nozzle 3. The second nozzle 3 is arranged on one side of the cutting gun 1, and the second nozzle 3 is arranged towards the lower part of the cutting gun 1 and communicated with the air supply device 7.

When cutting gun 1 was located the surface of water top assigned distance, the second nozzle 3 was blown to the surface of water of cutting gun 1 below, promoted the dross on the surface of water of cutting machine below to far away to guarantee that cutting gun 1 is not contacting with the dross in-process under stretching into the surface of water, thereby avoid dross to block up cutting gun 1, guarantee cutting gun 1's normal use and life-span.

Alternatively, the second nozzle 3 and the first nozzle 2 may share the same air supply device 7, or different air supply devices 7 may be connected to each other.

As shown in fig. 3, an air supply device 7 is connected to each of the second nozzle 3 and the first nozzle 2, and the second nozzle 3 communicates with the air supply device 7 through a second air supply duct 6. The second air supply duct 6 may be vertically disposed, and the second air supply duct 6 is connected with the first air supply duct 5 through the second connection member 83, thereby fixing the first and

second nozzles

2 and 3.

The second connecting member 83 connects the first air supply duct 5 and the second air supply duct 6 by clamping. Specifically, the second connecting member 83 includes a first clamping head and a second clamping head which are symmetrically arranged, and a second clamping hole for clamping the first gas supply pipe 5 and a third clamping hole for clamping the second gas supply pipe 6 are arranged between the first clamping head and the second clamping head. And the third bolt penetrates through the first chuck and the second chuck and then is in screwed fit with the third nut, so that the first chuck and the second chuck are fixed, and the first air supply pipeline 5 and the second air supply pipeline 6 are connected.

Before the third bolt and the third nut are tightened, the second gas supply duct 6 can rotate and slide up and down relative to the second connecting member 83, and the height of the second nozzle 3 and the orientation of the second nozzle 3 can be adjusted by the rotation and the sliding of the second gas supply duct 6, so that the gas ejected from the second nozzle 3 blows off the scum below the cutting gun 1.

In order to adjust the opening and closing of the second nozzle 3 and the flow rate of the air flow, a second opening and closing valve 61 and a second flow rate valve 62 may be provided on the second air supply duct 6. The second on-off valve 61 is used for controlling the on-off of the second gas supply duct 6, and the second flow valve 62 is used for controlling the flow rate of the gas supplied from the second nozzle 3.

In order to improve the automation degree of the plasma cutting machine, the plasma cutting machine further comprises a controller 9 and a detection assembly. The detection assembly can detect the distance from the end of the cutting gun 1 to the water surface, and the controller 9 is electrically connected with the detection assembly, the first switch valve 51, the first flow valve 52, the second switch valve 61 and the second flow valve 62 respectively. The controller 9 may control the air supply device 7 to supply air to the first and

second nozzles

2 and 3 according to the detection result of the detection member.

In particular, the detection assembly may comprise a distance sensor, for example a laser ranging sensor, detecting the distance between the cutting gun 1 and the water surface. When the detection assembly detects that the height of the cutting gun 1 above the water surface is equal to the designated distance, the detection assembly sends an electric signal to the controller 9, the controller 9 controls the second switch valve 61 to be opened according to the received electric signal, and adjusts the second flow valve 62 according to the requirement, so that the second nozzle 3 blows air to the water surface to blow away floating slag. Then, the cutting gun 1 continues to move towards the water surface and extends below the water surface. When the cutting torch 1 starts cutting, the controller 9 controls the first on-off valve 51 to be opened, and adjusts the first flow valve 52 as needed so that the first nozzle 2 injects compressed air into the water to prevent combustion of hydrogen.

The above description is only a preferred embodiment of the present invention, and for those skilled in the art, the present invention should not be limited by the description of the present invention, which should be interpreted as a limitation.

Claims

1. A plasma cutting machine comprising a cutting gun (1), characterized in that it further comprises:

a first nozzle (2), the first nozzle (2) being connected with the cutting gun (1); and

the air supply device (7) is connected with the first nozzle (2) and used for supplying compressed air;

the first nozzle (2) is an annular nozzle, the annular nozzle and the cutting gun (1) are coaxially arranged, and the cutting gun (1) penetrates through the annular nozzle;

the plasma cutter further includes:

the second nozzle (3) is arranged on one side of the cutting gun (1), the second nozzle (3) faces the lower part of the cutting gun (1), and the second nozzle (3) is communicated with the gas supply device (7);

the plasma cutter further includes:

the adjusting component, the adjusting component respectively with annular nozzle with cutting gun (1) is connected, the adjusting component can adjust annular nozzle with the relative position of cutting gun (1), so that annular nozzle with cutting gun (1) coaxial setting.

2. The plasma cutter of claim 1, wherein the adjustment assembly comprises:

the cutting gun comprises a first connecting piece (81), wherein one end of the first connecting piece (81) is connected with the annular nozzle, the other end of the first connecting piece is provided with a waist-shaped hole (811), and the waist-shaped hole (811) extends along the radial direction of the cutting gun (1);

be provided with mounting bracket (4) on cutting torch (1), the bolt passes waist shape hole (811) with be connected with the nut behind mounting bracket (4).

3. The plasma cutter of claim 2, further comprising:

first gas supply line (5), first gas supply line (5) respectively with annular nozzle with air feeder (7) intercommunication, first gas supply line (5) with cutting gun (1) is connected.

4. The plasma cutting machine according to claim 3, characterized in that the first connecting member (81) is fixed to the first gas supply duct (5) in a clamping manner, and the first gas supply duct (5) can rotate and slide up and down relative to the first connecting member (81).

5. The plasma cutting machine according to claim 3, characterized in that the first gas supply duct (5) is provided with a first on-off valve (51) and a first flow rate valve (52).

6. The plasma cutter according to any one of claims 1 to 5, further comprising:

a second gas supply duct (6), the second gas supply duct (6) being in communication with the second nozzle (3) and the gas supply device (7) respectively.

7. Plasma cutter according to claim 6, characterized in that the second gas supply duct (6) is provided with a second on-off valve (61) and a second flow valve (62).

8. The plasma cutter of claim 1, further comprising:

a detection assembly for detecting the distance of the end of the cutting gun (1) from the water surface; and

a controller (9), controller (9) with the detection component electricity is connected, is used for control air feeder (7) to first nozzle (2) with second nozzle (3) air feed.