JPS601534A - Method for checking penetration of air vent in complicated structure - Google Patents

Abstract

PURPOSE:To ensure the checking as to whether an air vent is not obstructed or not, by introducing a magnetic fluid in a structure, wherein bulkheads are provided in the inside and air vent are provided in the bulkheads, moving the fluid before and after the bulkheads by a magnet, and detecting the flow of the magnetic fluid by X-ray projection. CONSTITUTION:A magnetic fluid is introduced in the direction of an arrow A from an air introducing port 12 of a main body of a turbine blade 10. A magnet 32, which is provided at the outside, is moved to the front part of a bulkhead 16 as shown by an arrow B. The magnetic fluid in a main path 14 follows the magnet 32 and passes through an air vent 20. The fluid flows out into a front space 20 as shown by an arrow C. X rays are projected on the main body of the turbine blade 10 at the same time, and the flowing state of the magnetic fluid is confirmed. Thus the penetration state of the titled device is positively checked.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a method for inspecting internal ventilation holes of a complex structure.
In particular, the present invention relates to a penetration inspection method suitable for inspecting whether or not a cooling vent of a turbine can penetrate.

[Prior art]

Generally, a gas turbine blade has a cooling function inside the blade, and a cooling air passage is formed therein.

Examples of the structure of the cooling air passage are not shown in FIGS. That is, an air inlet 12 is formed at the base of the wing body 10, and partition walls 16, 18 are provided before and after the main passage 14 in the center. A plurality of ventilation holes 20 are formed in the partition wall 16 on the front edge side and communicate with a front space 22, and the front space 22 is connected to the outside via a discharge hole 24 opening at the front edge. Further, the partition wall 18 on the rear edge side forms a communication passage 26 with the inner wall of the upper edge, and the main passage 14 and the rear space 28 are communicated with each other. The rear space 28 has a plurality of discharge holes 3 bored at the trailing edge of the wing body 10.
0 communicates with the outside.

By the way, gas turbine blades having such a complicated structure are manufactured by a precision casting method, but if the cooling air passages in the structure are not formed to penetrate as designed, they will be abnormally heated and pose an unexpected danger. For this reason, conventionally, although it is possible to visually check the discharge holes 24 and 30 formed on the upper edge and trailing edge of the wing body 10, it is not possible to visually check the ventilation holes 20 formed in the internal partition wall 16. Therefore, penetration inspection using X-ray projection was performed.

However, if a minute rack occurs in the core that serves as the mold for the vent hole 20, and a thin foil-like flash is formed and the vent hole 20 is blocked, it cannot be detected by conventional inspection methods. There was a problem. This problem is not limited to gas turbine equipment, but also complex equipment with internal ventilation holes ((°
This is common to all four created things.

[Purpose of the invention]

The present invention addresses the above-mentioned conventional problems, and provides an internal ventilation hole penetration system that can reliably inspect the presence or absence of the ventilation hole penetration of a complex structure such as a turbine blade, which has ventilation holes in dark areas that cannot be visually confirmed. The purpose is to provide an inspection method.

[Structure of the invention]

In order to achieve the above object, the present invention provides a method for inspecting the internal ventilation hole of a complex 4 artifact, which has a partition wall inside the structure, such as a turbine blade, and a ventilation hole is bored in the partition wall. A magnetic fluid is introduced into the partition wall, the magnetic fluid is moved forward and backward of the partition wall using an external magnet, and penetration inspection is performed by confirming whether or not the magnetic fluid can flow by using an X-ray projection or the like.
fQ was completed.

With the above configuration, it is possible to confirm whether or not the magnetic fluid flows through the ventilation hole by using an X-ray photograph or directly, and it becomes possible to determine the state of blindness.

[Embodiments of the invention]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific embodiment of the method for inspecting internal ventilation holes in a complex structure according to the present invention will be described in detail below when applied to a gas turbine blade.

As described above, in the gas turbine blade shown in FIGS. 1 and 2, the ventilation hole 20 is formed in the partition wall 16 on the leading edge side in contact with the main passage 14, and the ventilation hole 20 cannot be visually inspected. Therefore, magnetic fluid is introduced as shown by arrow A from the air introduction port 12 provided at the base of the wing body 10. This magnetic fluid may be commercially available, and only a small amount that can fill the area in which the vent hole 20 is formed in the main passage 14 is sufficient.

Further, in order to hold the magnetic fluid in the main passage 141111 in advance, a magnet 32 is placed outside as shown in FIG. The magnet 32 may have a length corresponding to the length of the partition wall 16.

After this preparatory work, the magnet 32 is moved toward the leading edge of the wing body 10 as shown by arrow B. Due to the movement of the magnet 32, the magnetic fluid in the main passage 14 follows the magnet 32, flows through the ventilation hole 20, and flows out into the front space 22 as shown by arrow C. If the vent hole 20 is completely or incompletely blocked by the foil film-like casting flash, the magnetic fluid will not flow or will flow at an extremely reduced flow rate. At the same time as the magnet 32 moves back and forth in the partition wall 16, the turbine blade is X-ray projected and the state of flow of the magnetic fluid to the vent hole 20 before and after the magnet 32 is moved is confirmed directly or photographed to determine the penetration state. can.

The projection can be performed not only by X-rays but also by any other method as long as it can show the flow of magnetic fluid, and non-destructive testing means such as ultrasound can be used.

According to the inspection method according to this embodiment, the penetration inspection of the internal ventilation hole 20 can be directly confirmed, and the presence of a foil film-like blockage can also be confirmed. In addition, if the flow rate is extremely low, this indicates the presence of flash that is close to being blocked, so it is easy to determine whether it is within the allowable range or not, and has the advantage of being able to detect unexpected dangers. be.

Although the long magnet 32 is used in the above embodiment, it is also possible to use a small piece of magnet to pass through each ventilation hole 20 fAf. Alternatively, a method may be adopted in which the magnetic fluid is filled in the cut space 22 in advance.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to very easily inspect the presence or absence of penetration of the ventilation hole in the dark area.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal cross-sectional view of a gas turbine blade, and FIG. 2 is a cross-sectional view thereof. DESCRIPTION OF SYMBOLS 10... Wing body, 16... Partition wall, 20... Ventilation hole, 32... Magnet. Agent Patent attorney Tatsuyuki Unuma (and 1 other person) Figure 1 Figure 2

Claims (1)

[Claims] (1) In a method for inspecting the penetration of an internal ventilation hole of a structure in which a turbine blade or the like has a partition wall inside and a ventilation hole is bored in the partition wall, a magnetic fluid is introduced into the structure;
A 'fJi miscellaneous structure characterized in that the magnetic fluid is moved back and forth between the partition walls using an external magnet, and the penetration inspection is performed by confirming whether or not the magnetic fluid can flow through X-ray projection or the like. A method for inspecting internal ventilation holes of objects.