JP6379360B2 - Shield cup and cutting torch - Google Patents

Description

  The present disclosure relates to a plasma cutting torch used for cutting metal or the like and a shield cup attached to the plasma cutting torch, and more particularly to a shape of the shield cup.

  A conventional plasma cutting using a plasma cutting torch described in Patent Document 1 will be described with reference to FIG. FIG. 4 is a cross-sectional view at the tip of a conventional plasma cutting torch.

  As shown in FIG. 4, a conventional plasma cutting torch 100 includes a body fitting 101, an electrode 102, a tip 103, an orifice 104, a nozzle 105, a working gas introduction pipe 106, a screw fitting 107, and an insulating material. 108. The electrode 102 is fixed to the main body fitting 101 by a collar portion 109 of the electrode 102 and a screw 110 at the tip of the main body fitting 101. The electrode 102 has an inner recess 111 opened upward, a cathode material 112 at the tip, and a groove 113 formed in the flange 109. The working gas introduction pipe 106 has a hole 115 in the in-electrode working gas introduction pipe 114 which is the tip. An annular path 116 is provided between the in-electrode working gas introduction pipe 114 and the electrode 102. The chip 103 and the nozzle 105 are fixed to a screw fitting 107.

  The conventional plasma cutting torch 100 generates a pilot arc between the electrode 102 and the tip 103, and then generates a plasma arc, which is a main arc, between the electrode 102 and a base material (not shown). In addition, the working gas introduced from the working gas introduction pipe 106 and passing through the hole 115, the annular path 116, the opening of the main body fitting 101, and the opening of the orifice 104 flows into the space between the electrode 102 and the tip 103. 103 is ejected from the tip opening. Further, the working gas introduced from the working gas introduction pipe 106 and passing through the hole 115, the annular path 116, the opening of the main body 101, the opening of the orifice 104, and the opening of the screw fitting 107 is transferred between the tip 103 and the nozzle 105. And is ejected from the tip opening of the nozzle 105. In this way, the working gas that flows through the plasma cutting torch 100 and jets cools the electrode 102 and the tip 103, and contracts the plasma arc.

  In the conventional plasma cutting torch 100, the tip of the chip 103 and the base material are separated by 5 mm and the base material is cut.

JP-A-3-114677

  The conventional plasma cutting torch 100 has an insulating nozzle 105 in order to prevent the chip 103 to which a voltage is applied from coming into contact with an operator or a peripheral one. However, in order to avoid a short circuit between the tip 103 and the operator's finger, the tip 103 protrudes slightly from the nozzle 105. This makes it difficult for the operator to confirm the tip of the tip 103 and the state of the plasma arc during cutting of the base material, and the workability is reduced.

  The present disclosure corresponds to the shield cup (the “nozzle 105” of the prior art of the present disclosure) in which the visibility of the plasma arc during cutting is improved while maintaining safety by avoiding a short circuit between the tip and the operator's finger. ) And cutting torch.

  In order to solve the above-described problem, the shield cup of the present disclosure is detachable at the distal end of the main body portion of the cutting torch, and the first opening is provided at the distal end, and the second opening is provided on the side surface. The shield cup surrounds the side of the tip provided at the tip of the main body of the cutting torch, and the tip of the tip protrudes from the first opening of the shield cup toward the tip of the cutting torch. In addition, it can be attached to the tip of the main body of the cutting torch.

  In addition, the cutting torch of the present disclosure includes a main body portion, an electrode, a chip, and a shield cup. The electrode is attached to the center of the tip of the main body. The chip is attached to the tip of the main body so as to surround the side of the electrode. The shield cup is attached to the tip of the main body so as to surround the side of the chip. The shield cup can be attached to and detached from the tip of the main body. A first opening is provided at the tip of the shield cup, and a second opening is provided on the side surface of the shield cup. The tip of the tip protrudes from the first opening of the shield cup in the direction of the tip of the main body.

  According to the shield cup and the cutting torch of the present disclosure, the visibility of the plasma arc during cutting can be improved while maintaining safety by avoiding a short circuit between the chip and the operator's finger.

FIG. 1 is a diagram showing a schematic configuration of a plasma cutting torch in the embodiment. FIG. 2 is a diagram illustrating a shield cup in the embodiment. FIG. 3 is a view showing a shield cup in a modification of the embodiment. FIG. 4 is a cross-sectional view at the tip of a conventional plasma cutting torch.

(Embodiment)
A plasma cutting torch and a shield cup according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram showing a schematic configuration of a plasma cutting torch 1 in the present embodiment. FIG. 2 is a diagram showing the shield cup 7 in the present embodiment.

  As shown in FIG. 1, the plasma cutting torch 1 (cutting torch) is located on a main body portion 4 including a main portion 2 and a cover portion 3, an electrode 5, a chip 6 covering the electrode 5, and an outer side of the chip 6. And a shield cup 7 to be used. The electrode 5 is attached to the center of the tip of the main body 4 (particularly the main part 2) of the plasma cutting torch 1. The chip 6 is physically and electrically separated from the electrode 5, and is attached to the tip of the main body 4 (particularly the main part 2) of the plasma cutting torch 1 so as to surround the side of the electrode 5. ing. The electrode 5 and the chip 6 are made of a conductor, and a voltage can be applied to each of them via the main part 2. The shield cup 7 is physically separated from the chip 6 and attached to the tip of the main body 4 (particularly, the cover 3) of the plasma cutting torch 1 so as to surround the side of the chip 6. The shield cup 7 is made of an insulator and can be attached to and detached from the plasma cutting torch 1. The shield cup 7 prevents the chip 6 from coming into contact with the operator's finger.

  Moreover, the main part 2 of the plasma cutting torch 1 is provided with a gas flow path through which gas flows, and the gas flows as shown by arrows in FIG. As shown in FIG. 1, the gas flowing through the gas flow path of the main part 2 is divided into a working gas 11 and a shield gas 12 and is ejected from the plasma cutting torch 1 toward the base material 20.

  The working gas 11 is ejected from the opening at the tip of the chip 6 via the gap between the electrode 5 and the chip 6. The working gas 11 is ejected from the opening at the tip of the tip 6 while vortexing, and thereby the plasma arc generated between the electrode 5 and the base material 20 is mechanically throttled to the base material 20 as a high-temperature plasma arc. Induce. The working gas 11 also has an effect of blowing off the melt of the base material 20 melted by the plasma arc.

  The shield gas 12 is ejected from the opening (first opening) at the tip of the shield cup 7 via the space between the chip 6 and the shield cup 7. The shield gas 12 has the effect of assisting the straightness of the plasma arc and cooling the tip 6.

  Next, a method for cutting the base material 20 using the plasma cutting torch 1 will be described. First, a voltage is applied to the electrode 5 and the chip 6 while causing the working gas 11 and the shielding gas 12 to be ejected (a potential difference is generated between the electrode 5 and the chip 6), and the electrode 5 and the chip 6 are interposed. Generate a pilot arc. When the pilot arc is generated, a voltage is further applied to the base material 20 (a potential difference is generated between the electrode 5 and the base material 20), and the voltage applied to the chip 6 is stopped. Thus, the pilot arc shifts to a plasma arc (main arc) formed between the electrode 5 and the base material 20. With this plasma arc and the aforementioned working gas 11, the base material is melted and blown off, and the base material 20 is cut.

  Next, the shield cup 7 of the present embodiment will be specifically described with reference to FIGS. 1 and 2. As shown in FIGS. 1 and 2, the shield cup 7 has a front opening 71 and a side opening 72, and the rear end is connected to the cover portion 3 of the plasma cutting torch 1. The opening 71 is a hole provided at the tip of the shield cup 7 so that the shield gas 12 is ejected and the chip 6 protrudes toward the base material 20. The opening 72 has a cutout shape connected to the opening 71, and extends toward the rear end of the shield cup 7 (above the plasma cutting torch 1). In other words, the opening 72 has a concave shape opened at the tip of the shield cup 7.

  The opening 72 will be described more specifically with reference to FIG. The opening 72 is formed in such a size that the test finger 30 stipulated in JIS standard C0920 (IEC 60529) does not come into contact with the chip 6, that is, the operator's finger does not touch the chip and safety is ensured. ing. In particular, it is desirable that the test finger 30 does not contact the chip 6 even when the tip of the chip 6 and the base material 20 are separated from each other by about 5 mm, which is the same state as actual non-contact plasma cutting. The plasma cutting and the opening 72 are formed so that the tip of the chip 6 that is not visible to the operator during the cutting of the base material 20 can be seen through the opening 72. In particular, when the plasma cutting torch 1 is held vertically with respect to a horizontally disposed base material, it is desirable that the opening 72 is formed so that the tip of the chip 6 can be seen from the operator even at a depression angle of 45 degrees. . That is, it is preferable that an angle formed by a straight line from the tip of the chip 6 toward the upper end of the opening 72 and a straight line in the upward direction of the axis of the plasma cutting torch 1 is 45 degrees or less. Thereby, the operator can directly check the state of the plasma arc ejected from the tip of the tip 6 toward the base material, and can improve the processing quality (the state of the cut surface).

(Modification of the embodiment)
Next, a modification of the present embodiment will be described with reference to FIG. FIG. 3 is a view showing the shield cup 73 in this modification. The same components as those in FIG. 2 are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 3, the shield cup 73 of this modification has an opening 74 (second opening) on the side surface of the shield cup 73. The opening 74 is a window-like opening separated from the opening 71, and the outer periphery of the tip of the shield cup 73 is completely connected. Thereby, since the strength is higher, the width and length of the opening 74 can be set with a high degree of freedom, and the operator can more easily check. Moreover, since the opening 74 is independent, the operator's finger is more difficult to enter, and the risk of the operator touching the chip 6 can be further reduced.

  As described above, according to the shield cups 7 and 73 of the present disclosure and the plasma cutting torch 1 using the same, the plasma arc during cutting while ensuring safety by avoiding a short circuit between the tip and the operator's finger. Visibility can be improved.

  The shield cup and the plasma cutting torch of the present disclosure are industrially useful because they can improve the visibility of the plasma arc during cutting while ensuring the safety of the operator.

DESCRIPTION OF SYMBOLS 1 Plasma cutting torch 2 Main part 3 Cover part 4 Main body part 5 Electrode 6 Tip 7 Shield cup 11 Working gas 12 Shield gas 20 Base material 30 Test finger 71, 72, 74 Opening 73 Shield cup

Claims (6)

A shield cup made of an insulator that is detachable at the tip of the main body of the cutting torch for cutting the base material , has a first opening at the tip, and has a second opening at the side,
The tip of the tip protrudes from the first opening of the shield cup toward the tip of the cutting torch so as to surround the side of the tip provided at the tip of the main body of the cutting torch. Can be attached to the tip of the body portion of the cutting torch ,
The cutting torch is held vertically with respect to the base material, and the tip of the chip and the base material are separated by 5 mm, and between the shield cup and the base material, according to JIS standard (IEC 60529). When the specified test finger is sandwiched, the test finger and the tip do not contact,
A shield cup in which an angle formed by a straight line from the tip of the chip toward the upper end of the second opening and a straight line in the upward direction of the axis of the cutting torch is 45 degrees or less . The shield cup according to claim 1, wherein the second opening has a notch shape connected to the first opening. The shield cup according to claim 1, wherein the second opening has a window shape separated from the first opening. A cutting torch for cutting a base material,
The main body,
An electrode attached to the center of the tip of the main body,
A tip attached to the tip of the main body so as to surround a side of the electrode;
A shield cup made of an insulator attached to the tip of the main body so as to surround a side of the chip;
The shield cup is detachable at the tip of the main body,
A first opening is provided at a tip of the shield cup, and a second opening is provided on a side surface of the shield cup;
Distal end of the tip, protruding from the first opening of the shield cup in the direction of the distal end of said body portion,
The cutting torch is held vertically with respect to the base material, and the tip of the chip and the base material are separated by 5 mm, and between the shield cup and the base material, according to JIS standard (IEC 60529). When the specified test finger is sandwiched, the test finger and the tip do not contact,
The cutting torch, wherein an angle formed by a straight line from the tip of the tip toward the upper end of the second opening and a straight line in the upward direction of the axis of the cutting torch is 45 degrees or less . The cutting torch according to claim 4 , wherein the second opening has a notch shape connected to the first opening. The cutting torch according to claim 4 , wherein the second opening has a window shape separated from the first opening.

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