JPS6410594B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a radiation bomb spraying method, in particular a method in which a bottomed cylindrical material to be sprayed is used as one electrode, and a spraying material is placed between the other electrode and the material to be sprayed. This invention relates to a wire bomb spraying method in which a desired thermal spray coating is applied by disposing a certain wire and applying a large impact current to the wire.

BACKGROUND ART When thermally spraying the inner surface of a cylindrical material to be thermally sprayed using a beam blasting method, a conventional method is carried out with the configuration shown in FIG. In this configuration, the material to be thermally sprayed and the wire rod which is the thermal spraying material disposed at the center of the inner surface of the material to be thermally sprayed are electrically insulated.

In the conventional method, a wire rod is placed on the inner surface of a cylindrical material to be thermally sprayed, so if the material to be thermally sprayed is a cylindrical shape with an open top, for example a U-shaped bottom, a sufficiently large Unless a hole is made and a wire is passed through, it is impossible to thermally spray the inner surface of the material to be thermally sprayed. However, if a method of inserting an electrode inside, ie, a method of using a coaxial cable as shown in FIG. 2 (Patent No. 720023) is used, it is possible to partially coat the material by thermal spraying. Even in this case, there are drawbacks such as the fact that the deep part of the U-shaped inner diameter of the material to be thermally sprayed cannot be thermally coated because of the electrode 7 connected to the coaxial cable 9, and the thermal spraying efficiency is also poor. Therefore, if the material to be thermally sprayed has a cylindrical shape with an open top, for example, a U-shape with a bottom, it has been impossible to thermally spray the inner surface of the material by the wire bombardment spraying method on an industrial scale.

Problems to be Solved by the Invention The present invention aims to solve the above-mentioned problem, that is, it is not possible to thermally spray coat the inner surface of a cylindrical material to be thermally sprayed which is open at the top and has a bottom. It is something.

Means for Solving the Problems The present invention applies a large shock current to a wire rod, which is a thermal spraying material, placed on the inner surface of a bottomed cylindrical material with one end of the cylinder closed, that is, open at the top. In the wire bomb spraying method for thermally spraying the inner surface of the material to be thermally sprayed, one end of the wire, which is the thermal spraying material, is brought into electrical contact with a required part of the bottom of the material to be thermally sprayed, and the other end of the wire is This method is characterized in that it is placed in an electrically insulated state from the material to be thermally sprayed, and both electrodes are formed by a required portion of the material to be thermally sprayed and the other end of the wire. That is, to explain the structure in detail with reference to FIG. 3, one electrode 13 is electrically insulated around the periphery to prevent electrical discharge with the sprayed material 12, and one end of the wire 5, which is the sprayed material, is covered. It is fixed in contact with the center of the bottom of the thermal spray material 12, and the other end is connected to the electrode 13. That is, the material to be thermally sprayed itself serves as the other electrode. Next, a large impact current necessary and sufficient to melt and explode the wire 5 is applied to achieve the desired thermal spray coating.

Generally, as shown in Figure 1, the wire bomb spraying method is a method in which thermal spraying is performed with the material to be sprayed and the wire rod electrically insulated, so the present invention is essentially different from the conventional method. It is something.

Effect The method of the present invention does not perform thermal spraying while the material to be sprayed and the wire are electrically insulated, as in conventional methods, but the material to be sprayed also serves as one of the two electrodes. Therefore, even if the material to be thermally sprayed has a cylindrical shape with an open bottom, the inner surface of the material can be thermally sprayed.

Example As an example of a material to be thermally sprayed in the shape of a cylinder with an open bottom, the inner surface of a U-shaped part made of aluminum alloy with an inner diameter of 30 mm and a depth of 100 mm is coated with molybdenum. The wire bomb spraying was carried out using the configuration shown in FIG. 3 according to the present invention. The wire blast spraying conditions were as follows: the diameter of the molybdenum wire was 0.8 mm, the distance between the electrodes, that is, the distance between the electrode 13 and the center of the bottom of the material to be sprayed, was 130 mm, the capacitor charging capacity was 100 μF, and the charging voltage was 6 KV. As a result, the inner surface of the U-shaped part could be coated by thermal spraying.

Effects of the Invention It is a feature of the present invention that the material to be thermally sprayed also serves as one electrode, and for this reason, one end of the cylinder is closed, which is impossible with the conventional method, that is, the top is open. It has become possible to thermally spray the inner surface of a bottomed cylindrical material to be thermally sprayed using the wire bombardment spraying method.
An example of this bottomed cylindrical material to be thermally sprayed is a cylinder for an internal combustion engine in which a cylinder head and a cylinder are integrated. Since the present invention can be applied to this type of product, this effect is very large.

[Brief explanation of drawings]

Figure 1 is a diagram showing the configuration of a case in which the inner surface of a cylindrical material to be thermally sprayed is subjected to radiation blast spraying, Figure 2 is a diagram of the configuration in the case of radiation blast spraying to the inner surface of a long cylindrical material to be thermally sprayed, and Figure 3 is a diagram of the main body. FIG. 1 is a configuration diagram of a beam blast spraying method according to the invention. Also, code 1 is a capacitor, 2 is a switch, 3,
4, 7, 8, 13 are electrodes, 5 is a thermal spray wire, 6, 1
2 and 61 represent materials to be thermally sprayed, 9 represents a coaxial cable, and 15 represents an insulator.

Claims (1)

[Claims] 1. By applying a high impact current to a wire that is a thermal spraying material placed on the inner surface of a cylindrical material to be thermally sprayed with one end closed, that is, open at the top, the inner surface of the material to be thermally sprayed is In the wire bomb thermal spraying method, one end of the wire, which is the thermal spraying material, is brought into electrical contact with the required part of the bottom of the material to be thermally sprayed, and the other end of the wire is electrically insulated from the material to be thermally sprayed. A wire blast spraying method characterized in that both electrodes are formed by a desired part of the material to be sprayed and the other end of the wire.