JPH06257573A - Impeller flaw detecting device - Google Patents

Abstract

(57) [Summary] [Structure] In this flaw detection device, a flaw detection liquid coating layer B for making visible the cracks formed is formed in advance on a predetermined portion of the impeller 1. The upper surface of the flaw detection liquid coating layer B was covered with a resin coating layer C through which the flaw detection liquid coating layer B can be seen. [Effect] Since the flaw detection liquid is applied in advance, there is no need to apply it when checking for cracks. It can be inspected in a short time. The resin coating layer C can prevent the flaw detection liquid coating layer B from peeling off. It is possible to detect flaws even after long-term use.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impeller flaw detector for checking cracks generated in an impeller of a turbo compressor.

[0002]

2. Description of the Related Art Impellers of turbo compressors that have been used for a long period of time are subject to cracks, especially at the blade inlets and back, due to repeated start and stop and abnormal vibrations. Is likely to occur. Therefore, usually every year, the turbo compressor is disassembled, the impeller is removed, and the presence or absence of cracks is checked by using a stress paint or a penetrant flaw detection liquid.

In the case of the stress paint, after the stress paint was applied, it had to be naturally dried for about 28 hours, and the turbo compressor had to be stopped for a long time. Even in the case of penetrant flaw detection, the steps of pretreatment-penetration treatment-washing treatment-development treatment-development treatment-inspection must be performed, and similarly, it is necessary to stop the turbo compressor for a long time. there were.

Further, since it is an overhaul and inspection, there is a problem that the refrigerant is discharged, and it is not possible to perform it very often, and there is a problem in safety and reliability. An object of the present invention is to solve the above technical problems and to provide an impeller flaw detector which can check the presence or absence of cracks in a short time.

Another object of the present invention is to provide an impeller flaw detector which can check the occurrence of cracks in a short time without disassembling.

[0006]

According to a first aspect of the present invention, there is provided a flaw detector for an impeller according to claim 1, wherein a flaw detection liquid is applied to a surface of a predetermined portion of an impeller of a turbo compressor so that a crack can be visually recognized. It is characterized in that a layer and a resin coating layer which covers the upper surface of the flaw detection liquid coating layer and is transparent to the flaw detection liquid coating layer are formed in advance.

In order to achieve the above other object, the impeller flaw detector according to claim 2 has an introduction hole in the housing of the turbo compressor for introducing an optical fiber member for observing a predetermined portion of the impeller. It is characterized by being provided. In this case, it is preferable that the introduction hole is provided with a seal member that allows the introduction of the optical fiber member while maintaining the airtightness inside the housing.

[0008]

According to the structure of the invention as set forth in claim 1, since the flaw detection liquid is previously applied to a predetermined portion of the impeller, it is not necessary to apply it at the time of inspection. Further, since the flaw detection liquid coating layer is covered with the resin coating layer, the flaw detection liquid coating layer does not peel off even if the impeller is used for a long period of time.

According to the structure of the second aspect of the invention, by introducing the optical fiber member for observation through the introduction hole, it is possible to observe whether or not a crack has occurred without disassembling. In this case, by providing the seal member in the introduction hole, the optical fiber member can be introduced while maintaining the airtightness inside the housing.

[0010]

Embodiments will be described in detail below with reference to the accompanying drawings showing embodiments. FIG. 1 is a sectional view of a surface portion of an impeller for explaining a flaw detector for an impeller according to an embodiment of the present invention, FIG. 2 is a schematic sectional view of the impeller, and FIG. 3 is a schematic sectional view of a turbo compressor. .

Referring to FIG. 3, this turbo compressor is used for a refrigerator of an air conditioner, etc., and compresses a high-temperature refrigerant gas vaporized by taking latent heat from the outside by an evaporator (not shown). The high-temperature high-pressure refrigerant gas is supplied to a condenser (not shown), and a hub is provided at the center of the housing 14 via a speed increasing device 15 that is linked to a motor (not shown). The impeller 1 having 1c is rotatably supported, and the outlet 1b of the impeller 1 faces the diffuser A. At the inlet 1a side of the impeller 1, a guide vane 16 is blown by a motor 17 to blow air. The interior is adjustable. When the impeller 1 is rotationally driven at high speed, the refrigerant gas sucked into the impeller 1 is given a centrifugal force when passing between the hub 1c and the shroud 1d, and is guided to the scroll 4 via the diffuser A. . In this way, velocity energy is applied to the sucked refrigerant gas by centrifugal force, and this velocity energy is converted into pressure energy, whereby compression of the refrigerant gas is achieved.

At the blade inlet portion P and the back surface portion Q (see FIG. 2) of the impeller 1, a flaw detection liquid coating layer B and a resin coating layer C covering the flaw detection liquid coating layer B as shown in FIG. 1 are provided. It is applied and formed in advance before the assembly of the turbo compressor. The material for forming the flaw detection liquid coating layer B may be a known stress paint or a known penetration flaw detection liquid. Further, as the resin coating layer C, for example, a fluororesin or the like, which is transparent or translucent, has excellent chlorofluorocarbon resistance and has little friction, can be exemplified.

In addition, an optical fiber member L for observing the blade inlet portion B of the impeller 1 is introduced into the suction side portion of the housing 14 from the outside so that the optical fiber member L faces the blade inlet portion B. Are formed. In addition, an introduction hole 19 for introducing the optical fiber member L for observing the back surface portion Q of the impeller 1 from the outside and facing the back surface portion Q is provided in the shroud side wall portion of the diffuser A of the housing 14. Has been formed.

FIG. 4 and FIG. 5 show the seal structure of the inlet portion of the introduction hole 18. Referring to these figures,
The housing 14 is formed with a boss 20 having a threaded portion 20 a on the outer periphery at the peripheral portion of the introduction hole 18. The threaded portion 20a of the boss 20 has a tubular coupler nut 2
1 is screwed in, and in this state, the coupler nut 2
Reference numeral 1 denotes a cylindrical holder 22 that guides the optical fiber member L into the introduction hole 18 while holding the optical fiber member L.
Is connected to the boss 20. In this seal structure, by tightening or loosening the coupler nut 21, the seal member S1 made of a thin rubber plate or the like having the slit portion S1a in the introduction hole 18 is opened and closed, and the optical fiber member L is opened in the open state. Is allowed to be introduced. The outer periphery of the seal member S1 is fitted and fixed to the inner peripheral surface of the introduction hole 18 by an elastic repulsive force, and the seal member S1 will be described later on the holder 22 as the holder 22 enters the introduction hole 18. The slit S1a is opened by being pushed by the tip diameter reducing portion 22a.

The tip end reduced diameter portion 22a of the holder 22 is fitted in the introduction hole 18 in a slidable manner in the axial direction. An elastically compressible seal member S2 made of an annular thick rubber plate or the like is interposed between the end surface of the boss 20 and the tip shoulder portion 22b of the holder 22 that is continuous with the tip reduced diameter portion 22a. There is. Further, the rear end reduced diameter portion 22c of the holder 22 is
The coupler nut 21 is loosely fitted to the inner periphery of the rear end flange portion 21a, and the relative movement of the coupler nut 21 and the holder 22 in the axial direction enables the rear end flange portion 21a to contact the rear end shoulder portion 22d. Has become. Furthermore, the holder 2
On the inner peripheral surface of 2, the O that seals between the optical fiber member L and
A ring 24 is provided.

In this seal structure, the coupler nut 21
When tightening, the rear end flange portion 21a of the coupler nut 21 pushes the rear end shoulder portion 22d of the holder 22. As a result, the seal member S1 causes the reduced diameter portion 22 of the tip of the holder 22.
the slit S1a is pushed by the optical fiber member L
Is opened so that the seal member S2 is compressed and the sealing performance is improved.

According to this embodiment, the stress paint or the like is previously applied to the blade inlet portion P and the back surface portion Q of the impeller 1 which are easily damaged, so that it is not necessary to apply the stress paint at the time of inspection. As a result, the presence or absence of cracks can be checked in a short time. Further, since the flaw detection liquid coating layer B made of stress paint or the like is covered with the resin coating layer C, peeling of the flaw detection liquid coating layer B is prevented, and as a result, even if the impeller 1 of the turbo compressor is used for a long period of time, The function as a flaw detector is not lost.

Moreover, by introducing the optical fiber member L for observation through the introduction hole 18, it is possible to observe whether or not a crack is generated in a short time without disassembling. In addition, the seal members S1 and S2 provided in the introduction hole 18 can maintain the airtightness inside the housing 14 when the optical fiber member L is introduced, and can reliably prevent the refrigerant from being discharged.

The present invention is not limited to the above-mentioned embodiments, but various changes can be made without changing the gist of the present invention.

[0020]

As described above, according to the flaw detection device for an impeller according to the first aspect, since the flaw detection liquid coating layer is formed in advance on a predetermined portion of the impeller, it is not necessary to apply the flaw detection liquid for inspection. As a result, the presence or absence of cracks can be checked in a short time. Further, since the flaw detection liquid coating layer is covered with the resin coating layer, peeling of the flaw detection liquid coating layer is prevented, so that the function as the flaw detection device is not lost even if the impeller of the turbo compressor is used for a long period of time.

According to the second aspect of the invention, by introducing the optical fiber member for observation through the introduction hole, it is possible to observe the presence or absence of cracks in a short time without disassembling. In this case, by providing a seal member in the introduction hole, it is possible to maintain the airtightness of the inside of the housing when introducing the optical fiber member, and it is possible to reliably prevent the refrigerant from being discharged.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a main part of an impeller showing a flaw detection device for an impeller as an embodiment of the invention according to claim 1.

FIG. 2 is a schematic sectional view of an impeller.

FIG. 3 is a schematic cross-sectional view of a turbo compressor.

FIG. 4 is an enlarged sectional view of an essential part showing an introduction hole portion of an optical fiber member.

FIG. 5 is an enlarged sectional view of an essential part showing an introduction hole portion of an optical fiber member.

[Explanation of symbols]

 1 Impeller B Flaw Detection Liquid Coating Layer C Resin Coating Layer 14 Housing 18, 19 Inlet Hole L Optical Fiber Member S1, S2 Sealing Member

Claims (3)

[Claims] 1. A flaw detection liquid coating layer (B) for visually recognizing a crack generated on a predetermined portion (P, Q) surface of an impeller (1) of a turbo compressor, and the flaw detection liquid coating layer (B). An impeller flaw detection device characterized in that a resin coating layer (C) which covers the upper surface and is transparent to the flaw detection liquid coating layer (B) is formed in advance. 2. An introduction hole (18, 19) for introducing an optical fiber member (L) for observing a predetermined portion (P, Q) of the impeller (1) into a housing (14) of a turbo compressor.
The flaw detector for an impeller according to claim 1, further comprising: 3. A seal member (S1, S2) for allowing the introduction of the optical fiber member (L) while maintaining the airtightness of the housing (14) is provided in the introduction hole (18, 19). The flaw detection device for an impeller according to claim 2.