JPH0686873U - Electrodes for plasma arc processing - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an electrode for plasma arc machining having a long service life and a uniform service life. A plasma arc machining electrode (1) having a high melting point insert (3) attached to the tip of an electrode base material (2) made of copper or copper alloy cooled by a fluid supplied to a fluid passage. The mounting hole portion 201 of the body 3 and the fluid passage portion 202 penetrate, the inner diameter of the penetrating portion 203 is formed to be slightly smaller than the inner diameter of the mounting hole portion 201, and the base portion of the penetrating portion 203 and the insert body 3 are inserted. It is characterized in that it comes into contact with the insertion end.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an electrode used in a plasma arc processing torch for welding or cutting a work piece.

[0002]

[Prior art]

 Generally, a plasma arc processing torch is shown in FIG. 3, 1 is a plasma arc processing electrode cooled by a fluid, and this electrode 1 is a hollow electrode substrate made of copper or copper alloy. 21 and a high-melting-point insert 3 such as hafnium or tungsten attached to the tip of the electrode base material 21. 4 is an electrode supporting member made of a conductive material for supporting the electrode 1, 5 is an insulating sleeve provided outside the electrode supporting member 4, 6 is a chip supporting member made of a conductive material provided outside the insulating sleeve 5, A torch body 7 is constituted by the above 4 to 6. Reference numeral 8 denotes a hollow tip supported by the tip of the tip support member 6, and a plasma flow ejection hole 801 is formed at the center of the tip. Reference numeral 9 is an insulating cup, 10 is a cooling water guide tube, and the cooling water introduced from the supply hose 11 cools the electrode 1 and then flows out of the torch through the drainage hose 12 through the passage shown by the arrow.

In the above-mentioned torch, electric power is supplied between the electrode 1 and the work piece, and an appropriate plasma arc forming fluid G such as air, oxygen, nitrogen, or argon is supplied from the plasma jetting hole 801 of the chip 8. A jet is generated to generate a plasma jet, and the workpiece is processed by this plasma jet.

Further, as shown in FIG. 4, the electrode 1 is provided with a recessed portion having a diameter slightly smaller than the outer diameter of the insert 3 at the tip end portion of the electrode base material 21, and a cylindrical insertion portion is inserted into the tip recessed portion 211. The body 3 is driven in and fitted. Further, the cooling water flowing from the cooling water guide pipe 10 circulates in the fluid passage portion 212, and the heat generated at the electrode tip portion is sequentially taken out of the electrode 1.

[0005]

[Problems to be solved by the device]

 By the way, in the electrode 1, since the cylindrical insert body 3 is driven into the tip concave portion and fitted therein, when the insert body 3 is fitted, the air in the tip concave portion 211 seals the insert body 3 as if the insert body 3 were a lid. In most cases, the insertion end surface of the insert body 3 and the bottom surface of the end recess portion 211 are not completely in contact with each other as the insert body 3 is fitted into the end recess portion 211. For this reason, heat is not rapidly transferred from the insertion end surface of the insert body 3 to the bottom surface of the tip recess 211, and as a result, the life of the electrode 1 is short.

[0006] Furthermore, in combination with the fact that the inside of the tip recess 211 becomes a vacuum state when the insert 3 is fitted as described above, the end face machining of the tip recess 211 and the insert 3 is costly and highly accurate. Therefore, the distance from the insertion end surface of the insert body 3 to the bottom surface of the fluid passage portion 212 varies, and thus the cooling of the insert body 3 does not become constant and the life of the electrode 1 varies. there were.

The present invention has been made in view of the above problems, and an object thereof is to provide an electrode for plasma arc machining having a long service life and a uniform service life.

[0008]

[Means for Solving the Problems]

 The present invention is applied to an electrode for plasma arc processing in which a high melting point insert is attached to the tip of an electrode base material made of copper or copper alloy cooled by a fluid supplied to a fluid passage. . The feature is that the mounting hole portion of the insert and the fluid passage portion penetrate, the inner diameter of the through portion is formed slightly smaller than the inner diameter of the mounting hole portion, and the base portion of the through portion and the insertion portion are inserted. That is, the contact is made with the insertion end of the body.

[0009]

【Example】

 Hereinafter, the present invention will be described in detail with reference to illustrated embodiments. In FIG. 1, reference numeral 2 denotes an electrode base material made of copper or copper alloy that is cooled by a fluid, and 3 is an insert having a high melting point, such as hafnium or tungsten, and is formed in, for example, a cylindrical shape. 201 is a hole for mounting the insert body 3, and is formed from the center of the tip of the electrode base material 2 by, for example, drilling. A cooling fluid passage portion 202 is formed, for example, by drilling from the side opposite to the mounting hole 201 and penetrates the mounting hole 201. Reference numeral 203 denotes a penetrating portion formed by processing the mounting hole 201 and the fluid passage portion 202, and the inner diameter of the penetrating portion 203 is formed to be slightly smaller than the inner diameter of the mounting hole 201. The insert 3 is mounted in the mounting hole 201 such that the insertion end of the insert 3 abuts on the base of the penetrating portion 203, and the electrode 1 is constituted by the electrode base 2 and the insert 3. Has been done.

In the electrode 1 having the above structure, when the insert body 3 is driven into the mounting hole 201 of the electrode base material 2 and fitted therein, the air in the mounting hole 201 is such that the insert body 3 fits into the mounting hole 201. As it is inserted, it is sequentially ejected from the penetrating portion 203, so that the inserting body 3 can be smoothly inserted until the circumferential portion of the inserting end surface of the inserting body 3 firmly contacts the base portion of the penetrating portion 203. it can.

Furthermore, since the insertion position of the insert 3 is determined by the contact of the insertion end of the insert 3 with the base of the penetrating portion 203, the insert 3 can be positioned easily and reliably. .

On the other hand, most of the insertion end surface of the insert 3 is in direct contact with the cooling fluid, so that the heat is rapidly transferred from the insertion end surface to the cooling fluid, and the cooling fluid is replaced one after another. By the cooling fluid supplied, the heat generated in the insert 3 during the plasma processing is sequentially taken out of the electrode 1, so that the insert 3 is effectively cooled. That is, the life of the electrode is extended. Moreover, since the electrode 1 is thermally stabilized during plasma processing, the electrode life becomes constant.

Further, since the circumference of the insertion end of the insert 3 is in contact with the end of the penetrating portion 203, the cooling fluid may leak through the gap to the tip side of the electrode 1. Absent.

Further, another specific example will be described. In FIG. 1, the high melting point insert body 3 is formed in a cylindrical shape having a diameter of 1 to 3 mm and a length of 3 to 5 mm, for example. The mounting hole 201 is formed by drilling from the center of the tip of the electrode substrate 2, and its inner diameter is slightly larger than d + Δd, where d is the diameter of the insert body 3. On the other hand, the fluid passage portion 202 is formed by drilling from the side opposite to the mounting hole 201, penetrates the mounting hole 201, and the inner diameter of the penetrating portion 203 is formed to be slightly smaller than the diameter of the insert body 3. ing. The insert body 3 is inserted into the mounting hole 201, and the insert body 3 is pressure-held in the inserting direction so that the insert end surface of the insert body 3 is in close contact with the end surface of the penetrating portion 203. The insert body 3 is mounted in the mounting hole 201 by crimping in the central direction.

In the electrode 1 having the above-described structure, when the insert body 3 is crimped into the mounting hole 201 of the electrode base material 2, the insert end surface of the insert body 3 is brought into contact with the end surface of the penetrating portion 203, whereby the insert body The insertion position of 3 is determined stably, and since the insert 3 is crimped while being pressed and held in the insertion direction, the insert 3 is mounted so that the circumferential part of the insertion end face is in close contact with the end face of the penetration part 203. It Therefore, even if the electrode 1 is heated, the insert body 3 is held by the restraining force at the time of crimping, the insert body 3 is detached, or the circumferential portion of the insert end face of the insert body 3 and the end face of the penetrating portion 203 are separated. The adhesion does not become weak.

That is, when the insert body 3 is crimped, as in the case of inserting the insert body 3, most of the insertion end surface of the insert body 3 is in direct contact with the supplied cooling fluid so as to be replaced one after another. Therefore, the insert 3 is effectively cooled, and the life of the electrode is extended. Moreover, since the electrode 1 is thermally stabilized during plasma processing, the electrode life becomes constant. Furthermore, since the circumference of the insertion end of the insert 3 is in close contact with the penetrating part 203, the cooling fluid does not leak to the tip side of the electrode 1.

2 (A) to 2 (C) are views showing other embodiments of the present invention, respectively, and since the structure of the electrodes is the same as that shown in FIG. However, detailed description is omitted.

In FIG. 2A, the mounting hole 201 is formed by machining or forging so that the bottom surface of the mounting hole 201 is flat, and the fluid passage portion 202 is formed by drilling from the direction opposite to the mounting hole 201. It penetrates the hole 201.

Further, in FIG. 2B, the mounting hole 201 is formed by drilling, and the fluid passage portion 202 is machined or forged so that the bottom surface becomes flatter in the direction opposite to the mounting hole 201. It is formed and penetrates the mounting hole 201.

On the other hand, in FIG. 2C, the mounting hole 201 and the fluid passage portion 202 are formed by machining or forging so that the bottom surfaces of the mounting hole 201 and the fluid passage portion 202 are flat, and the mounting hole 201 and the fluid passage portion 202 are separated from each other. A penetrating portion 203 is provided by drilling so as to penetrate.

In the electrode 1 having the above structure, the insert body 3 is mounted in the mounting hole 201 of the electrode base material 2 so that the circumferential portion of the insertion end face of the insert body 3 is in close contact with the end portion of the penetrating portion 203. As a result, the same effect as that of the above-described embodiment can be obtained.

[0022]

[Effect of device]

 As is clear from the above description, according to the present invention, most of the insertion end surface of the insert body is brought into direct contact with the supplied cooling fluid so that the insert body is effectively cooled. Therefore, the life of the electrode is extended. Moreover, since the electrodes are thermally stable, the electrode life is constant.

Further, since the circumference of the insertion end of the insert is in close contact with the end of the penetrating portion, the cooling fluid travels through the gap between the side surface of the insert and the mounting hole during plasma machining. Since there is no risk of leakage to the tip side of the electrode and the formation of plasma arc can be prevented from being disturbed, stable plasma processing can be performed.

Further, in manufacturing the electrode, in combination with the fact that the positioning of the insertion body at the time of insertion can be performed easily and surely by the end portion of the penetrating portion, the mounting hole portion of the insertion body and the fluid communication hole are inserted. Since the passage penetrates, the inside of the mounting hole does not become a vacuum state when the insert body is attached, so it is easy to manufacture an accurate electrode with a fixed insert position. You can

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a vertical sectional view showing another embodiment of the present invention.

FIG. 3 is a sectional view of a main part of a general plasma arc processing torch.

FIG. 4 is an enlarged cross-sectional view of a main part in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 electrode 2 electrode base material 3 insert body 201 mounting hole portion 202 cooling fluid passage portion 203 penetrating portion

Claims (1)

[Scope of utility model registration request] 1. A plasma arc machining electrode in which a high melting point insert is attached to the tip of an electrode base material made of copper or copper alloy cooled by a fluid supplied to a fluid passage. The mounting hole part of and the passage part for fluid penetrate,
An electrode for plasma arc processing, wherein an inner diameter of the penetrating portion is formed to be slightly smaller than an inner diameter of the mounting hole portion, and a base portion of the penetrating portion and an insertion end portion of the insert contact each other.