JP2005271136A - Peening method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To apply residual compressive stress to the surface of a treated part of an engine part by causing pulse-like discharge between a discharge electrode and the surface of an energizing tape to make plasma collide with the surface of the energizing tape. <P>SOLUTION: An insulating tape 29 is stuck to a metallic product 1 to cover a treated part 5a, the energizing tape 31 is stuck to the insulating tape 29 to be aligned with the surface shape of the treated part 5a, and pulse-like discharge D is caused between the discharge electrode 23 and the energizing tape 31 in insulating working liquid L, whereby plasma P is explosively generated, and while the plasma P is sealed not to be released to the outside by the working fluid L, it is collided with the surface of the energizing tape 31. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a peening method for applying a residual compressive stress to a treated portion of a metal product such as an engine component in a gas turbine engine, for example.

  For example, in the field of gas turbine engines, it is common to increase the fatigue strength by applying a residual compressive stress to the pressure surface of the rotor blade dovetail and the pressure surface of the rotor disk dovetail groove. On the other hand, as a peening method for giving residual compressive stress to the processing part of the engine part such as the pressure surface of the dovetail of the rotor blade, the pressure surface of the dovetail groove of the rotor disk, etc., a method by shot particle injection, There is a method using laser light emission.

  Here, the former peening method uses a high-pressure facility in a factory to inject the shot particles from a shot nozzle, thereby causing the shot particles to collide with a portion to be processed of the engine component, and the engine. This is a method of applying a residual compressive stress to a part to be processed. In the latter peening method, a laser beam oscillated by a laser oscillator is emitted from a laser head through a photoconductive system to generate an explosion explosively, and a residual compressive stress is applied to a portion to be processed of the engine part. Is a way to give

In addition, there exist some which are shown to patent document 1 and patent document 2 as a prior art relevant to this invention.
JP 2001-277118 A JP 2000-246468 A

  By the way, since the high-pressure equipment is used in the former peening method, there are many restrictions on the layout of the processing line when installing a processing line equipped with a peening line process in a factory. Therefore, there is a problem that it is not easy to effectively use the space in the factory.

  Moreover, since the laser oscillator and the photoconductive system are required to implement the latter peening method, the apparatus that performs the peening method becomes a large-scale and the cost required to implement the peening method increases. There is.

In the invention according to claim 1, in the peening method for applying residual compressive stress to the processing target portion of the metal product,
Using an insulating tape having insulating properties, an insulating tape attaching step of attaching the insulating tape to the metal product so as to cover the portion to be processed;
An energizing tape affixing step for affixing the energizing tape to the insulating tape so as to match the surface shape of the treated portion, using an energizing tape having conductivity;
After the insulating tape attaching step and the energizing tape attaching step are completed, using the discharge electrode, a pulsed discharge is generated between the discharge electrode and the surface of the energizing tape in an insulating working fluid. A discharge step of causing the plasma to collide with the surface of the energizing tape while generating the plasma explosively and sealing the plasma so as not to escape to the outside by the processing liquid;
It is characterized by comprising.

Here, the location where energization has once occurred in the energizing tape is vaporized and is not energized (discharged) again. Therefore, the plasma can be made to collide substantially uniformly over the entire surface of the energizing tape.
Note that the order of the energizing tape attaching process may be after the insulating tape attaching process or before the insulating tape attaching process. Moreover, as long as the said insulating tape is affixed so that the said to-be-processed part may be covered, it is not necessary to affix so that it may match with the surface shape of the said to-be-processed part.

In the invention according to claim 2, in the peening method for applying the residual compressive stress to the treated portion of the metal product,
Using a peening tape having a conductive layer having electrical conductivity on the front side and an adhesive layer having insulating properties on the back side, the peening tape is affixed to the metal product so as to match the surface shape of the processing target portion Tape attaching process;
After the tape application step is completed, the discharge electrode is used to explode by generating a pulsed discharge between the discharge electrode and the surface of the peening tape in an insulating working fluid. A discharge step of causing the plasma to collide with the surface of the peening tape while generating plasma and sealing the plasma so as not to escape to the outside by the processing liquid;
It is characterized by comprising.

Here, the location where energization has once occurred in the energization layer of the peening tape is vaporized and is not energized (discharged) again. Therefore, the plasma can be collided substantially uniformly over the entire surface of the peening tape.
The invention according to claim 3 is characterized in that the metal product is an engine part in a gas turbine engine, in addition to the matters specifying the invention according to claim 1 or claim 2.

  According to the first aspect of the present invention, the metal product is produced by causing the plasma to collide with the surface of the energizing tape by generating a pulsed discharge between the discharge electrode and the surface of the energizing tape. Since a residual compressive stress can be given to the surface of the to-be-processed part, the peening method can be carried out with a simple apparatus without using the high-pressure equipment in the factory. Therefore, when a processing line equipped with a peening line process is installed in a factory, restrictions on the layout of the processing line are reduced, and effective use of space in the factory can be facilitated, and a peening method The cost required for the implementation can be reduced.

  Further, after the current-carrying tape is affixed to the insulating tape so as to match the surface shape of the treated portion of the metal product, the plasma may collide substantially uniformly over the entire surface of the current-carrying tape. Therefore, the residual compressive stress can be applied substantially uniformly over the entire surface of the treated portion of the metal product, and the fatigue strength of the treated portion of the metal product is further improved.

  According to the second aspect of the present invention, the metal product is caused to collide the plasma with the surface of the peening tape by generating a pulsed discharge between the discharge electrode and the surface of the peening tape. Since a residual compressive stress can be given to the surface of the to-be-processed part, the peening method can be carried out with a simple apparatus without using the high-pressure equipment in the factory. Therefore, when a processing line equipped with a peening line process is installed in a factory, restrictions on the layout of the processing line are reduced, and effective use of space in the factory can be facilitated, and a peening method The cost required for the implementation can be reduced.

  Further, after the peening tape is pasted so as to match the surface shape of the treated portion of the metal product, the plasma may collide substantially uniformly over the entire surface of the conductive layer of the peening tape. Therefore, the residual compressive stress can be applied substantially uniformly over the entire surface of the treated portion of the metal product, and the fatigue strength of the treated portion of the metal product is further improved.

  According to invention of Claim 3, there exists an effect similar to the effect of the invention of Claim 1 or Claim 2.

  An engine component to be subjected to the peening method according to the best mode of the present invention, an electric discharge machine according to the best mode of the present invention, a first peening method according to the best mode of the present invention, and the best mode of the present invention The 2nd peening method concerning a form is demonstrated with reference to FIGS. 1-4.

  Here, FIG. 1 is a schematic diagram illustrating a first peening method according to the best mode of the present invention, and FIG. 2 illustrates a second peening method according to the best mode of the present invention. FIG. 3 is a schematic front view of an electric discharge machine according to the best mode of the present invention. FIG. 4 shows a moving blade as an example of an engine component of a gas turbine engine. It is a schematic diagram which shows a part of rotor disk.

  As shown in FIG. 4, the metal mechanical parts to be subjected to the peening method according to the best mode of the present invention are engine parts of a gas turbine engine such as a moving blade 1 and a rotor disk 3. By executing the peening method according to the best mode of the present invention, residual compressive stress is applied to the pressure surface 5 a of the dovetail 5 of the rotor blade 1 and the pressure surface 7 a of the dovetail groove 7 of the rotor disk 3.

  As shown in FIG. 3, an electric discharge machine 9 according to the best mode of the present invention uses a bed 11 as a machine base, and a bed 13 is provided on the bed 11 and the table 13 is an X-axis. It can be moved in the X-axis direction (left and right in FIG. 3) by driving a servo motor (not shown) and can be moved in the Y-axis direction (front and back in FIG. 3) by driving a Y-axis servo motor (not shown). Is possible.

  The table 13 is provided with a processing tank 15 for storing a processing liquid L such as insulating oil, and a support plate 17 is provided in the processing tank 15. The support plate 17 is provided with a fixture 19 for mounting engine parts (the moving blade 1, the rotor disk 3, etc.).

  A processing head 21 is provided above the bed 11 (upper in FIG. 3) via a column (not shown). The processing head 21 is driven in the Z-axis direction (not shown) by driving a Z-axis servo motor (not shown). It can move in the vertical direction in FIG. The machining head 21 is provided with an electrode holder 25 that holds the discharge electrode 23.

  The electrode holder 25 and the fixture 19 are electrically connected to a power source 27.

  As shown in FIG. 1, the first peening method according to the best mode of the present invention applies residual compressive stress to the parts to be processed of engine parts such as the pressure surface 5a of the rotor blade 1 and the pressure surface 7a of the rotor disk 3. It is a method for giving, Comprising: It consists of the following insulating tape sticking processes, an energizing tape sticking process, and a discharge process.

Insulating Tape Affixing Step The insulating tape 29 is affixed to the rotor blade 1 so as to cover the pressure surface 5a using an insulating tape 29 having an insulating property (see FIG. 1A).

  In addition, as long as the insulating tape 29 is affixed so that the pressure surface 5a may be covered, it is not necessary to affix so that it may match the surface shape of the pressure surface 5a.

Current-carrying tape affixing process After the insulating tape affixing process is completed, the current-carrying tape 31 is affixed to the surface of the insulating tape 29 so as to match the surface shape of the pressure surface 5a by using a current-carrying tape 31 having conductivity. (See FIG. 1 (b)).

  In addition, the said electrically-conductive tape sticking process may be before the said insulating tape sticking process.

Discharge process After the current-carrying tape attaching process is completed, the table 13 is moved in the X-axis direction by driving the X-axis servo motor and the Y-axis servo motor in a state where the moving blade 1 is attached to the fixture 19. By moving in the axial direction (at least in any direction), the moving blade 1 is positioned so that an appropriate region on the pressure surface 5a is located below the discharge electrode 23 (downward in FIG. 3) (see FIG. 3). ). Then, while the discharge electrode 23 is moved integrally with the machining head 21 in the Z-axis direction by driving the Z-axis servo motor (see FIG. 3), a pulse is generated between the discharge electrode 23 and the energizing tape in the machining liquid L. -Like discharge D is generated (see FIG. 1C). As a result, the plasma P is explosively generated, and the plasma P is sealed so as not to escape to the outside by the working liquid L, and is collided with the surface of the current-carrying tape 31 to remain in the appropriate region on the pressure surface 5a. A compressive stress can be given (refer FIG.1 (d)). The above operation is repeated until residual compressive stress is applied to the entire area of the pressure surface 5a.

  Here, the portion of the energizing tape 31 once energized is vaporized and is not energized (discharged) again. Therefore, the plasma P can be made to collide substantially uniformly over the entire surface of the energizing tape 31.

  In addition, although the residual compressive stress can be given to the pressure surface 5a of the moving blade 1 by implementation of the 1st peening method concerning the best form of this invention by the above, other engines, such as the pressure surface 7a of the rotor disk 3, etc. Residual compressive stress can also be applied to the part to be processed by performing the first peening method.

  As described above, according to the first peening method according to the best mode of the present invention, the pulsed discharge D is generated between the discharge electrode 23 and the surface of the current-carrying tape 31, thereby Since the plasma P is caused to collide with the surface, residual compressive stress can be applied to the surfaces of the processing parts of the engine parts (the pressure surface 5a of the rotor blade 1, the pressure surface 7a of the rotor disk 3, etc.). The first peening method can be implemented with a simple device without using pressure equipment. Therefore, when a processing line equipped with a peening line process is installed in the factory, restrictions on the layout of the processing line are reduced, and effective use of the space in the factory can be facilitated. The cost required for the implementation of the first peening method can be reduced.

  In addition, the plasma P can collide substantially uniformly over the entire surface of the energizing tape 31 after the energizing tape 31 is attached to the insulating tape 29 so as to match the surface shape of the processed part of the engine component. The residual compressive stress can be applied substantially uniformly over the entire surface of the treated part of the engine part, and the fatigue strength of the treated part of the engine part is further improved.

  As shown in FIG. 2, the second peening method of the present invention is a method for applying residual compressive stress to the parts to be processed of engine parts such as the pressure surface 5 a of the rotor blade 1 and the pressure surface 7 a of the rotor disk 3. Thus, the process includes a tape attaching process and a discharging process as described below.

Tape Affixing Step Using the peening tape 33, the peening tape 33 is affixed to the rotor blade 1 so as to match the surface shape of the pressure surface 5a (see FIG. 2A).

  Here, a current-carrying layer 35 having electrical conductivity is provided on the front side (upper side in FIG. 2) of the peening tape 33, and an insulating adhesive is provided on the back side (lower side in FIG. 2) of the peening tape 33. A layer 37 is provided.

Discharge process After the tape attaching process is completed, the table 13 is moved in the X-axis direction and the Y-axis by driving the X-axis servo motor and the Y-axis servo motor with the moving blade 1 attached to the fixture 19. The moving blade 1 is positioned so that an appropriate region on the pressure surface 5a is located below the discharge electrode 23 by moving in the direction (at least in any direction) (see FIG. 3). Then, the discharge electrode 23 is moved integrally with the machining head 21 in the Z-axis direction by driving the Z-axis servo motor (see FIG. 3), and between the discharge electrode 23 and the peening tape 33 in the machining liquid L. A pulsed discharge is generated (see FIG. 2B). Accordingly, the plasma P is explosively generated, and the plasma P is sealed so as not to escape to the outside by the processing liquid L, while being collided with the surface of the current-carrying layer 35 of the peening tape 33, and the pressure surface 5a Residual compressive stress can be applied to the region as appropriate. The above operation is repeated until residual compressive stress is applied to the entire area of the pressure surface 5a.

  Here, the location where energization has once occurred in the energization layer 35 of the peening tape 33 is vaporized and is not energized (discharged) again. Therefore, the plasma P can be collided substantially uniformly over the entire surface of the conductive layer 35 of the peening tape 33.

  Although the residual compressive stress can be applied to the pressure surface 5a of the rotor blade 1 by the second peening method according to the best mode of the present invention as described above, other engine parts such as the pressure surface 7a of the rotor disk 3 can be applied. Residual compressive stress can also be applied to the portion to be processed by performing the second peening method.

  As described above, according to the second peening method according to the best mode of the present invention, the peening tape 33 is energized by generating a pulsed discharge D between the discharge electrode 23 and the surface of the peening tape 33. Since the surface of the layer 35 is made to collide with the plasma P, residual compressive stress can be applied to the surfaces of the parts to be processed (the pressure surface 5a of the rotor blade 1, the pressure surface 7a of the rotor disk 3, etc.) of the engine component. The second peening method can be carried out with a simple device without using the high-pressure equipment. Therefore, when a processing line equipped with a peening line process is installed in the factory, restrictions on the layout of the processing line are reduced, and effective use of the space in the factory can be facilitated. The cost required for implementing the peening method 2 can be reduced.

  Further, since the peening tape 33 is affixed to the engine part so as to match the surface shape of the portion to be processed, the plasma P can collide substantially uniformly over the entire surface of the conductive layer 35 of the peening tape 33. The residual compressive stress can be applied substantially uniformly over the entire surface of the treated part of the engine part, and the fatigue strength of the treated part of the engine part is further improved.

  The present invention is not limited to the description of the best mode of the invention described above, and can be implemented in various other modes by making appropriate modifications.

It is a schematic diagram explaining the 1st peening method concerning the best form of this invention. It is a schematic diagram explaining the 2nd peening method concerning the best form of this invention. 1 is a schematic front view of an electric discharge machine according to the best mode of the present invention. FIG. 2 is a schematic diagram showing a part of a rotor blade and a rotor disk as an example of an engine component of a gas turbine engine.

Explanation of symbols

D discharge L machining fluid P plasma 1 rotor blade 3 rotor disk 5 dovetail 5a pressure surface (processed part)
7 Dovetail groove 7a Pressure surface (processed part)
9 Electrical Discharge Machine 23 Discharge Electrode 29 Insulating Tape 31 Current Tape 33 Peening Tape 35 Current Layer 37 Adhesive Layer

Claims (3)

In a peening method for applying residual compressive stress to a treated part of a metal product,
Using an insulating tape having insulating properties, an insulating tape attaching step of attaching the insulating tape to the metal product so as to cover the portion to be processed;
An energizing tape affixing step for affixing the energizing tape to the insulating tape so as to match the surface shape of the treated portion, using an energizing tape having conductivity;
After the insulating tape attaching step and the energizing tape attaching step are completed, a pulsed discharge is generated between the discharge electrode and the energizing tape in the insulating working liquid using the discharge electrode. A discharge step of causing the plasma to explode and causing the plasma to collide against the surface of the energizing tape while sealing the plasma so that it does not escape to the outside;
A peening method comprising: In a peening method for applying residual compressive stress to a treated part of a metal product,
Using a peening tape having a conductive layer having electrical conductivity on the front side and an adhesive layer having insulating properties on the back side, the peening tape is affixed to the metal product so as to match the surface shape of the processing target portion Tape attaching process;
After the tape attaching step is completed, by using a discharge electrode, a pulsed discharge is generated between the discharge electrode and the surface of the peening tape in an insulating working fluid, thereby explosively. A discharge step of causing plasma to collide with the surface of the current-carrying tape while sealing the plasma so as not to escape to the outside by the working liquid;
A peening method comprising:   The peening method according to claim 1, wherein the metal product is an engine component in a gas turbine engine.

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