JP3119550U - Gas cutting crater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas cutting crater capable of concentrating a flame formed by a mixed gas of a fuel gas and preheated oxygen on a steel material to be cut and thereby making a cutting speed remarkably high.
SOLUTION: A barrel middle part 1, an inner cylinder part 2 and an outer cylinder part 3 are provided, and a crater tip surface 2b and a crater tip surface 3b are arranged in substantially the same plane, and a first sheet 1a of the barrel middle part 1 is cut oxygen. Around the cutting oxygen introduction port 4a, a plurality of preheating oxygen introduction ports 4a are introduced into the second sheet 1b of the middle cylinder 1 and a plurality of fuel gases are introduced into the second sheet 1b or the third sheet 1c of the middle cylinder 1 Each of the ports 6 is formed, a gas mixing passage 7 of preheated oxygen and fuel gas is formed downstream of each fuel gas inlet 6, and a cut oxygen passage formed in the center of the cut oxygen inlet 4 a and the inner cylinder portion 2. 4c is communicated, and a mixed gas passage 9 and a tapered slit 8 are formed in this order between the inner cylinder part 2 and the outer cylinder part 3, and the inclination angle of the slit 8 is defined as the central axis of the crater. The angle was set to 10 to 20 degrees, preferably 15 to 20 degrees.
[Selection] Figure 1

Description

  The present invention relates to a gas cutting crater that heats a steel material to be cut by a flame formed by a mixed gas of fuel gas and preheated oxygen and injects cutting oxygen to cut it.

  In gas cutting, after preheating by injecting a flame toward the steel to be cut, cutting oxygen is injected toward the preheated portion to burn the steel to be cut, and at the same time, combustion products are excluded from the base material, and this reaction is performed. By moving the gas cutting crater in a continuous state, a continuous groove is formed along the moving path to cut the target shape.

As this type of gas cutting crater, for example, the one shown in Patent Document 1 is known. As shown in FIG. 4, the inner cylinder part 2 is coaxially connected to one end of the trunk middle part 1, and the outer cylinder part 3 is externally fitted to the inner cylinder part 2. The crater front end surface 3b of the outer cylinder part 3 is arranged in substantially the same plane, the cutting oxygen introduction port 4a is provided in the first sheet 1a of the cylinder middle part 1, and the second part of the cylinder middle part 1 around the cutting oxygen introduction port 4a. A plurality of preheated oxygen inlets 5 are formed in the seat 1b, a plurality of fuel gas inlets 6 are formed in the second sheet 1b or the third sheet 1c of the trunk middle portion 1, and preheated downstream of each fuel gas inlet 6 A gas mixing path 7 of oxygen and fuel gas is formed, a cutting oxygen introduction port 4a formed in the middle cylinder portion 1 and a cutting oxygen passage 4c formed in the central portion of the inner cylinder portion 2 are communicated, and the inner cylinder portion 2 and the outer cylinder portion 3 are formed with a mixed gas passage 9 and a tapered slit 8 in order, and formed by a mixed gas of fuel gas and preheated oxygen. It is configured to cut by ejecting cutting oxygen while heating the cut steel flame.
JP 2003-314808 A

According to the above prior art, the time required for piercing can be shortened while maintaining the perpendicularity of the upper edge of the cut surface. However, when hydrogen-based fuel gas having a high combustion rate is used, the flow rate of the mixed gas of fuel gas and preheated oxygen from the slit 8 to the tip surface 3b of the crater is slower than the combustion rate of the fuel gas. There is a risk of generating backfire due to the reason, and since there is little radiant heat, the combustion heat per mole cannot be concentrated and applied to the heat input part of the cutting part about 1/8 of hydrogen compared to propane. If the fuel gas is not supplied in a large amount, there is a problem that the cutting speed is not improved.

The present invention has been made as a result of earnest research to solve the above-mentioned problems, and is thus constructed as described below.
In other words, the invention described in claim 1 has the above-described conventional basic configuration in which the inner cylindrical portion 2 is coaxially connected to one end of the trunk middle portion 1 and the outer cylindrical portion 3 is connected to the inner cylindrical portion 2. The outer end part 2b of the inner cylinder part 2 and the crater front end face 3b of the outer cylinder part 3 are arranged in substantially the same plane, and the cut oxygen inlet 4a is formed in the first sheet 1a of the trunk middle part 1 Around the cutting oxygen inlet 4a, a plurality of preheated oxygen inlets 5 are formed in the second sheet 1b of the middle cylinder 1, and a plurality of fuel gas inlets 6 are formed in the second sheet 1b or third sheet 1c of the middle cylinder 1, respectively. In addition, a gas mixing path 7 of preheated oxygen and fuel gas is formed downstream of each fuel gas inlet 6, and is formed at the center of the cut oxygen inlet 4 a formed in the trunk middle portion 1 and the inner cylinder portion 2. A structure in which the cut oxygen passage 4c is communicated, and the mixed gas passage 9 and the tapered slit 8 are sequentially formed between the inner cylinder portion 2 and the outer cylinder portion 3. In the gas cutting tip having a preferably 10-20 degrees inclination angle of the tapered-off slit 8 with respect to the crater of the central axis, characterized in that it comprises a structure set at 15 to 20 degrees.

The invention described in claim 2 relates to the gas cutting crater according to claim 1, characterized in that a mixed gas of hydrogen and petroleum gas or a mixed gas of hydrogen and natural gas is used as the fuel gas. To do.

  In the device according to claim 1, in the gas cutting crater having the above-mentioned conventional basic configuration, the inclination angle of the tapered slit 8 is set to 10 to 20 degrees with respect to the central axis of the crater, preferably 15 to 20 degrees. Therefore, the flame formed by the mixed gas of the fuel gas and the preheated oxygen can be concentrated on the steel material to be cut, so that the cutting speed can be remarkably increased.

  Further, in the invention described in claim 2, by using a mixed gas of hydrogen and petroleum gas or a mixed gas of hydrogen and natural gas as the fuel gas, the flow velocity due to the rapid throttling effect of the channel cross-sectional area is increased. Combined with the effect of the increase phenomenon, backfire does not occur, and the cutting speed can be significantly increased.

  Hereinafter, a preferred embodiment of the gas cutting crater (hereinafter abbreviated as a crater) will be described with reference to the drawings. 1 is a front view showing a partial cross section of a crater according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of an inner cylinder in the crater shown in FIG. 1, (A) is a front view showing a partial cross section, and (B) is a left side. FIG. 3C is a sectional view taken along the line aa in FIG. 2A, and FIG. 3 is a front view showing a partial sectional view of the outer cylinder.

  The crater shown in FIGS. 1 to 3 was developed to use hydrogen, which has a higher combustion rate than propane gas, as a fuel gas, and when a mixed gas of fuel gas and preheated oxygen is injected and ignited. The formed flame is concentrated at one point, and the heat energy is concentrated at the cutting point.

  As shown in FIG. 1, the crater includes a cylinder middle part 1 having a function of mixing fuel gas and preheated oxygen, an inner cylinder 2 that is fastened to the cylinder middle part 1 and integrally formed, and an inner cylinder 2. And an outer cylinder 3 that is externally fitted. The trunk middle portion 1 has a function of receiving cutting oxygen, preheated oxygen and fuel gas supplied from a cutting torch (not shown) in a state where leakage is prevented and mixing the preheated oxygen and fuel gas inside. For this reason, sheets 1 a to 1 c that are connected to the sheet portion of the cutting torch and seal each gas are formed in the trunk middle portion 1.

  As shown in FIGS. 1 and 2, a cutting oxygen introduction port 4a for supplying cutting oxygen is formed at the center of a sheet 1a formed in the cylinder middle portion 1, and a female screw is provided at the other end of the cutting oxygen introduction port 4a. Part 4b is formed. A plurality of preheated oxygen inlets 5 for supplying preheated oxygen to the seat 1b are formed, and a fuel gas inlet 6 for supplying fuel gas to the seat 1c is further formed. The fuel gas introduction port 6 is connected to the preheating oxygen introduction port 5 through a gas mixing path 7 formed in the inside of the trunk 1, and when the preheating oxygen and the fuel gas are supplied, both gases are passed through the gas mixing path 7. It is comprised so that it can mix well.

  A male screw portion 2a is formed at the base end portion of the inner cylinder 2, and the other end side (crater tip end face 2b side) is once reduced in outer diameter and then increased in outer diameter, and then toward the tip portion. A tapered tip end taper portion 2c is formed. The taper angle is set in a range of 10 ° to 20 ° with respect to the central axis. Further, a cutting oxygen passage 4c for supplying cutting oxygen is formed at the center in the axial direction of the inner cylinder 2 with a predetermined length. The cutting oxygen passage 4c has a crater front end surface 2b side corresponding to the thickness of the steel plate. A cut oxygen spout 4d having a different diameter is formed. A plurality of slits 8 are formed on the outer periphery of the tip side taper portion of the inner cylinder 2. The body middle part 1 and the inner cylinder 2 are integrally formed by fastening the male thread part 2 a to a female thread part 4 b formed in the body middle part 1.

  As shown in FIG. 3, the outer cylinder 3 has a body portion 3 a having an inner diameter larger than the outer diameter of the inner cylinder 2, and the crater tip surface 3 b side has an angle substantially equal to the tip taper portion 2 c of the inner tube 2. It is formed in a taper shape. Further, when the outer cylinder 3 is externally fitted to the inner cylinder 2, the crater front end surface 3 b and the crater front end surface 2 b of the inner cylinder 2 are configured to be in substantially the same plane. When the inner cylinder 2 is fastened to the middle cylinder 1 and the outer cylinder 3 is externally fitted to the inner cylinder 2, a mixed gas passage 9 is formed between the inner cylinder 2 and the inner surface of the trunk 3a of the outer cylinder 3. . Further, the slit 8 formed in the tip tapered portion 2c of the inner cylinder 2 is regulated by a tapered surface formed on the crater tip surface 3b side of the outer cylinder 3 and constitutes an independent mixed gas injection port.

  In the crater, the outer diameter is once reduced on the crater tip surface 2b side of the inner cylinder 2, and the outer diameter is increased again, and then a tip tapered portion 2c having a taper angle toward the crater tip surface 2b side is formed. . The tip tapered portion 2c has a taper angle of 10 ° to 20 ° with respect to the central axis of the crater, and the axial length is substantially equal to or slightly shorter than the outer diameter of the inner cylinder 2, In the present embodiment, the size of the tip tapered portion 2c is 8 mm from the crater tip surface 2b side, and the diameter of the crater tip surface 2b is 7 mm.

  In the crater configured as described above, when preheating oxygen is supplied to a cutting torch and hydrogen or hydrogen / petroleum gas mixed gas, hydrogen / natural gas mixed gas is supplied as fuel gas, and preheated oxygen is supplied. After being mixed in the gas mixing path 7 in the middle cylinder 1 and flowing into the mixed gas passage 9, it is injected from the slit 8. When the mixed gas is ignited in this state, a flame is formed from the slit 8. Therefore, it is possible to preheat the steel sheet by arranging the steel sheet facing the crater.

  When a hydrogen or hydrogen / petroleum gas mixed gas, a hydrogen / natural gas mixed gas and a preheated oxygen mixed gas are injected from the crater and ignited, a white flame is formed slightly toward the central axis of the crater. For this reason, it has the function of preheating by concentrating one point on the steel sheet, and it is possible to concentrate the thermal energy at the cutting location compared to the conventional gas cutting crater using propane gas as the fuel gas, cutting speed It is possible to speed up.

  Here, the heat energy can be concentrated on the cut portion because the width of the hydrogen flame is small and has straightness, and the shape of the tip tapered portion 2c having a taper angle tapered toward the tip of the crater tip surface 2b. It seems to be due to. More specifically, since the hydrogen flame is small in width and straight, the turbulence is smaller than the flame in the case of using propane gas as the fuel gas for the cut oxygen ejected from the cut oxygen ejection port 4d, and the inner cylinder Centered on the hydrogen flame formed by the mixed gas injection port which is regulated by the slit 8 formed in the tip tapered portion 2c of 2 and the taper surface formed on the tip side 3b side of the outer cylinder 3 Thermal energy concentrates toward the shaft side. In other words, it seems that the cutting speed increases because the influence on the disturbance of the flow of cutting oxygen is small. Moreover, it seems that the cutting speed is increased because the tip surfaces 2b and 3b of the inner cylinder 2 and the outer cylinder 3 are located in substantially the same plane.

  A comparison between a comparative example (sample No. 1) of a crater based on the prior art (Japanese Patent Laid-Open No. 2003-314808) and a cutting result (sample No. 2 to 5) actually performed using the above crater. They are shown in Table 1, Table 2 and Table 3, respectively.

As is apparent from these results, the cutting speed is obtained by using the above-mentioned crater according to the present invention in which the inclination angle of the tapered slit is within a range of 10 to 20 °, preferably 15 to 20 ° during the groove cutting. Is confirmed to improve.

It is a partial sectional view front view of the gas cutting crater according to the embodiment of the present invention. It is explanatory drawing of the inner cylinder in the gas cutting crater shown in FIG. 1, (A) is a front view showing a partial cross section, (B) is a left side view, and (C) is a view taken along line aa in FIG. It is sectional drawing. It is a partial sectional view front view of an outer cylinder similarly. It is a fragmentary sectional front view of the conventional gas cutting crater.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Middle body part, 1a * 1b * 1c ... sheet | seat, 2 ... Inner cylinder part, 2a ... Male screw part, 2b ... Tinder tip surface, 2c ... Tip taper part, 3 ... Outer cylinder part, 3a ... Trunk part, 3b ... Front end surface of crater, 4a ... cutting oxygen introduction port, 4b ... female screw part, 4c ... cutting oxygen passage, 4d ... cutting oxygen jet port, 5 ... preheating oxygen introduction port, 6 ... fuel gas introduction port, 7 ... gas mixing passage, 8 ... slit, 9 ... mixed gas passage.

Claims (2)

An inner cylinder part (2) is coaxially connected to one end of a cylinder middle part (1) for mixing fuel gas and preheated oxygen, and an outer cylinder part (3) is externally fitted to the inner cylinder part (2). The front end surface (2b) of the inner tube portion (2) and the crater front end surface (3b) of the outer tube portion (3) are arranged in substantially the same plane, and are formed on the first sheet (1a) of the trunk middle portion (1). The cutting oxygen inlet (4a) is connected to the second sheet (1b) of the cylinder middle part (1) around the cutting oxygen inlet (4a) with a plurality of preheated oxygen inlets (5). A plurality of fuel gas inlets (6) are respectively formed in the second sheet (1b) or the third sheet (1c), and gas mixture of preheated oxygen and fuel gas is provided downstream of each fuel gas inlet (6). A passage (7) is formed, and a cutting oxygen introduction port (4a) formed in the trunk middle portion (1) communicates with a cutting oxygen passage (4c) formed in the central portion of the inner cylinder portion (2), and Between the tube portion (2) and the outer tube portion (3), a mixed gas passage (9) and a tapered slit (8) are sequentially formed. In the configuration gas cutting tip forms,
A gas cutting crater characterized in that the angle of inclination of the tapered slit (8) is set to 10 to 20 degrees, preferably 15 to 20 degrees with respect to the central axis of the crater.   2. The gas cutting crater according to claim 1, wherein a mixed gas of hydrogen and petroleum gas or a mixed gas of hydrogen and natural gas is used as the fuel gas.