JPH10183087A - Repairing of mechanical component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for repairing a mechanical component which can prevent thermal deformation around a repair portion and has no adverse effect on the sliding property. SOLUTION: This method for repairing a mechanical component comprises the steps of: cutting-out a defect portion 3 generated in the sliding portion of a mechanical part component 1; blasting the bottom of a recess; degreasing the blasted area; coating the recess 4 with an epoxy resin adhesive 5 blended with molybdenum disulfide; and conducting finishing upon curing of the adhesive by cutting out the adhesive-coated face so as to render the level of the coated face identical to the level of the mechanical component in its surface around the coated face. If necessary, a reinforcing fiber is incorporated into the adhesive.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a repair method for repairing a defective portion generated in a sliding portion of a machine component.

[0002]

2. Description of the Related Art For example, while supporting a shaft rotating at high speed for a long period of time, a bearing such as a gear box, which is an auxiliary component of a gas turbine, has cracks and holes due to wear and corrosion. May occur. If such a defective portion is left as it is, the shaft cannot be smoothly supported. Therefore, when a defective portion is found, it is necessary to immediately repair the corresponding mechanical part or replace it with a new mechanical part.

Conventionally, when repairing the above-mentioned mechanical parts, generally, a build-up welding technique by TIG welding is used.

[0004]

By the way, the conventional TI
The method of repairing mechanical parts using overlay welding by G welding has the following disadvantages. That is, when the mechanical part is made of, for example, an aluminum alloy, the heat conductivity is good, so that a large amount of heat escapes to the surroundings, so that a large amount of heat needs to be applied to the welded portion, resulting in a large thermal deformation around the repaired portion. was there. Also, due to the effect of heat or the addition of welding material, the structure of the repaired part is different from the structure of other parts of the machine part, and the coefficient of friction between the repaired part and other parts is reduced. On the contrary, there is also a disadvantage that this has a bearing on slidability.

[0005] The present invention has been made in view of such circumstances, and it is possible to prevent thermal deformation in the vicinity of a repaired part, and in addition, to repair mechanical parts that do not impair slidability. The aim is to provide a method.

[0006]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a defect removing step for removing a defect generated in a sliding portion of a mechanical component, And applying an epoxy resin-based adhesive containing molybdenum disulfide to the recesses to be formed. In the invention according to claim 2, after the adhesive application step, when the adhesive is hardened, a finishing step of shaving off the adhesive applied surface so as to be flush with the surface of the surrounding mechanical parts is provided. It is characterized by. In the invention according to claim 3, between the defect removing step and the adhesive applying step, a blast step of roughening the bottom surface of the concave portion,
Thereafter, a degreasing step of removing grease from the roughened surface is provided. In the invention described in claim 4, the content of molybdenum disulfide is 5 as the adhesive.
-15% by volume. The invention according to claim 5 is characterized in that reinforcing fibers are mixed into the adhesive in addition to molybdenum disulfide.

According to the present invention, repair is basically performed using an epoxy resin-based adhesive, and the repair is performed without applying heat. Prevention of the occurrence of thermal deformation of the portion and, in addition, the addition of molybdenum disulfide to the epoxy resin adhesive ensure good lubrication even after repair.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows steps of a method for repairing mechanical parts according to the present invention, and FIG. 2 is a cross-sectional view showing how a mechanical part is actually repaired by the method. In FIG. 2, reference numeral 1 denotes a part of a metal mechanical component 1 such as aluminum used for a bearing portion of a gear box or the like, which is an auxiliary component of a gas turbine. The mechanical component 1 has a circular hole 2 formed at a substantially central portion, and the shaft 2 (not shown) is rotatably supported by the circular hole 2. Therefore, the inner peripheral portion 2a of the circular hole 2 is a sliding portion that moves relatively to the shaft.

Due to the fact that the above-mentioned shaft is supported for a long time on the inner peripheral portion 2a of the circular hole 2 of the mechanical component 1, FIG.
A defective portion 3 as shown in FIG.
Hereinafter, a method of repairing the defective portion 3 will be specifically described.

<Cleaning Step> In order to repair the defective portion 3, as shown in FIG. 1, first, the defective portion 3 and its peripheral portion are cleaned. As a cleaning method, there is a method of using a water flow jetted with a strong pressure, a method of using a mixed flow of water and bubbles, a method of jetting a cleaning liquid to the defective portion 3 in advance or at the same time as jetting water. .

<Inspection Step> Although dust and the like adhering to the defective portion 3 are removed in the above-described process, the defective portion 3 after cleaning is removed.
Inspect its properties in detail. Through this inspection, the size or depth of the defect 3 can be ascertained, and the amount of cutting of the defect 3 to be performed in the next process is determined based on the size or depth.

<Defective portion removing step> The defective portion 3 and its surroundings are cut or ground to remove the defective portion 3 and the like. At this time, the area around the defect 3 is also removed.
This is because the boundary of the defective portion 3 is uncertain, and a portion where the defective portion 3 is likely to be removed is also removed. Then, as a result, the defective portion 3
The concave portion 4 is formed at and around the location where there is. In order to remove the defective portion 3, for example, a milling machine, a drilling machine, a grinding machine, or the like is used.

<Blasting Step> The bottom surface of the concave portion 4 formed in the defect removing step is subjected to sandblasting for roughening. At this time, masking may be performed in advance to protect the periphery of the recess 4.

<Degreasing Step> Next, in order to remove the grease from the inner peripheral surface of the recess 4, the grease is removed using a solvent or the like.

<Preheating Step> Next, the area around the recess 4 is heated. The purpose of this heating is to shorten the solidification time of an adhesive 5 to be applied to the recess 4 described later.

<Adhesive Application Step> Next, the heated recess 4
Then, an epoxy resin-based adhesive 5 containing molybdenum disulfide is applied to the inside thereof, and the mixture is built up. At this time, the content of molybdenum disulfide in the adhesive 5 is such that the friction coefficient (including both dynamic and static) of the solidified adhesive after the buildup is substantially equal to the friction coefficient of the base material of the mechanical member 1. It is determined to be. Normally,
The content of molybdenum disulfide is determined within the range of 5 to 15% by volume. When the content is 5% by volume or less, it is difficult to exhibit the good lubricating performance of molybdenum disulfide. On the other hand, when the content is 15% by volume or more, the adhesive force of the adhesive itself may decrease. This is because both lubricity and adhesiveness can be satisfied. Further, reinforcing fibers may be mixed into the epoxy resin adhesive 5 as needed. Glass fibers,
Examples include carbon fiber, boron fiber, aramid fiber, and metal fiber.

<Finishing Step> When the applied adhesive is hardened, the upper part of the surface to which the adhesive 5 is applied is scraped so as to be flush with the surface of the surrounding mechanical parts. Thereby, the sliding surface A having the same shape as before the repair is obtained.

According to the above-mentioned repair method, the repair is performed using the epoxy resin adhesive 5, and the repair is performed without applying heat. It is possible to prevent a situation where a portion is thermally deformed.
Since molybdenum disulfide is added to the steel, good lubricity can be ensured even after repair.

FIG. 3 shows another embodiment of the mechanical part 1 repaired by the method of the present invention. In this form,
The concave portion 10 formed when the defective portion 3 is removed has a dovetailed groove shape, and the epoxy resin-based adhesive 5 containing molybdenum disulfide is applied to the inside of the dovetailed concave portion 10 and is built up. Since the concave portion 10 is formed in a groove shape as described above, even when the bonding strength between the bottom surface or the side surface of the concave portion 10 and the epoxy resin adhesive 5 is weak, the epoxy resin adhesive 5 does not come out of the concave portion 10. Can be prevented.

The scope of the present invention is not necessarily limited to engine accessory parts of gas turbines, but may be applied to any mechanical parts having sliding parts.

[0021]

As described above, the present invention has the following excellent effects. Basically, it is a method of repairing using epoxy resin adhesive, and it is a method of repairing without applying heat. Can be prevented. In addition, since molybdenum disulfide is mixed with the epoxy resin-based adhesive, good lubricity can be ensured even after repair. Also, between the defect removing step and the adhesive applying step,
By providing the blasting step and the degreasing step, the adhesive strength of the epoxy resin-based adhesive to the base material of the machine component can be increased. Further, the content of the molybdenum dihydrate is set to 5 to 5.
When the content is 15% by volume, both lubricity and good adhesiveness of the adhesive can be satisfied. Furthermore, if reinforcing fibers are mixed into the adhesive, the strength of the repaired portion can be further increased.

[Brief description of the drawings]

FIG. 1 is a process chart showing an embodiment of the present invention.

FIG. 2 is a sectional view of a main part of a mechanical part for explaining a process of a repair method according to the present invention.

FIG. 3 is a sectional view of a main part of a mechanical part showing another example of the repair method according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mechanical part 2 Circular hole 2a Inner peripheral part 3 Defect part 4 Concave part 5 Adhesive 10 Concave part A Lubrication surface

Claims (5)

[Claims] 1. A step of removing a defective part (3) generated in a sliding part of a mechanical part (1), and an epoxy resin system containing molybdenum disulfide in a concave part (4) formed by said step. An adhesive application step of applying an adhesive (5). 2. The method according to claim 1, further comprising the step of finishing the adhesive applied surface so as to be flush with the surface of the surrounding mechanical parts when the adhesive is cured after the adhesive applying step. The method for repairing mechanical parts according to claim 1. 3. A step of providing a blast step of roughening the bottom surface of the concave portion and a subsequent degreasing step of removing grease from the roughened surface between the defect removing step and the adhesive applying step. The method for repairing mechanical parts according to claim 1 or 2, wherein: 4. The method according to claim 1, wherein the adhesive has a content of molybdenum disulfide of 5 to 15% by volume. 5. The method for repairing mechanical parts according to claim 1, wherein a reinforcing fiber is mixed in the adhesive in addition to molybdenum disulfide.