JP5208070B2 - Water jet peening method and apparatus - Google Patents

Description

  The present invention relates to a water jet peening method and an apparatus therefor, and more particularly, to a water jet peening method suitable for improving tensile residual stress of a structure in a nuclear reactor to compressive residual stress by water jet peening. And an apparatus for the same.

  When residual stress exists near the surface of the welded part and heat-affected zone of the components of the nuclear reactor, water jet peening (hereinafter referred to as WJP) is applied to the welded zone and the heat-affected zone. Thus, the tensile residual stress existing in the vicinity of the surface of the component member is improved to the compressive residual stress. WJP is performed by injecting a high-pressure water flow from a nozzle in water in a state where a component for improving residual stress is immersed in water. A shock wave is generated by crushing bubbles contained in the jetted water flow. When this shock wave collides with the surface of the constituent member in water, the tensile residual stress near the surface of the constituent member is improved to the compressive residual stress. For this reason, generation | occurrence | production of the stress corrosion crack (SCC) in a structural member is suppressed. The stress improvement method by WJP is described in, for example, Japanese Patent No. 2841963, Japanese Patent No. 3530005, Japanese Patent Laid-Open No. 8-71919, and Japanese Patent Laid-Open No. 6-47668.

  In the construction of WJP on components, methods for confirming the state of construction of WJP are proposed in Japanese Patent Laid-Open Nos. 8-71919 and 6-47668.

  In JP-A-8-71919, WJP is applied to a conduit that is attached to the bottom of a reactor pressure vessel and passes through the bottom. This WJP is applied to the portion of the conduit inside the reactor pressure vessel. A high-pressure water flow is jetted from a nozzle existing in the water near the WJP construction target portion of the conduit, and a shock wave generated by collapsing bubbles contained in the water flow collides with the surface of the conduit in the reactor pressure vessel. Acoustics generated when an AE sensor (acoustic emission) attached to the outer surface of the conduit outside the reactor pressure vessel collides with a portion of the conduit inside the reactor pressure vessel during WJP construction. The signal is detected and an AE signal (sound power) is output. Based on the AE signal, it is confirmed whether or not the residual stress has been sufficiently improved for the conduit subjected to WJP. When the residual stress is not sufficiently improved, the injection condition (injection pressure) of the injected water flow is controlled and the nozzle position is adjusted.

  Japanese Patent Laid-Open No. 6-47668 describes that a piezoelectric ceramic (PZT) sensor is installed on a nozzle in the vicinity of an injection port of a nozzle that injects a high-pressure and high-speed water flow during WJP construction. When a high-pressure water flow is jetted from the nozzle, the PZT sensor detects an impact pulse (cavitation occurrence event) generated in the nozzle. The frequency distribution of the signal output from the PZT sensor based on the detected shock pulse is analyzed by a frequency analyzer. A determination device that inputs the analysis result of the frequency distribution outputs a control signal based on the dominant frequency obtained from the frequency distribution and the comparison result between the amplitude and these set values. The distance between the nozzle and the surface of the WJP work object is adjusted based on the dominant frequency, and the discharge pressure of the pump that supplies water to the nozzle is adjusted based on the amplitude of the dominant frequency.

Japanese Patent No. 2841963 Japanese Patent No. 3530005 JP-A-8-71919 Japanese Patent Laid-Open No. 6-47668

  In the WJP described in Japanese Patent Laid-Open No. 8-71919, an acoustic signal (elastic wave) generated when a shock wave collides with a portion in a reactor pressure vessel of a conduit at the time of WJP construction is generated. It is detected by an AE sensor attached to the outer surface of the conduit on the outside. However, this AE sensor is not only based on the elastic wave generated in the conduit by the shock wave generated by the collapse of bubbles contained in the water flow injected from the nozzle, but also by the impact force when the injected water flow directly collides with the conduit. Elastic waves generated in the conduit are also detected. By the way, the shock wave generated by the collapse of the bubbles greatly contributes to the improvement of the tensile residual stress existing near the surface of the conduit to the compressive residual stress. For this reason, the elastic wave generated by the impact force when the jetted water stream directly collides with the conduit reduces the reliability of the determination result of whether the improvement of the residual stress of the conduit by WJP is sufficient. In addition, when there are a plurality of conduits and WJP is applied to these conduits in order, it is necessary to change the conduit where the AE sensor is installed in accordance with the conduit where the WJP is applied. That is, it takes time and effort to remove the AE sensor from the conduit where the WJP construction has been completed, and then attach the AE sensor to the conduit where the WJP is constructed.

  In the WJP described in Japanese Patent Laid-Open No. 6-47668, since the PZT sensor is attached to the nozzle used for the construction of WJP, the above-mentioned problems caused by the WJP described in Japanese Patent Laid-Open No. 8-71919 are solved. The However, since the PZT sensor is attached to the nozzle, the WJP described in Japanese Patent Laid-Open No. 6-47668 has the following new problem. Since the PZT sensor is provided in the nozzle, this PZT sensor detects an elastic wave based on the flow vibration of high-pressure water containing bubbles passing through a narrow injection port. That is, in the WJP described in Japanese Patent Laid-Open No. 6-47668, the detected elastic wave is strongly influenced by the number of bubbles contained in the high-pressure water flow passing through the injection port.

  As will be described later, when a high-pressure water flow is jetted from the nozzle toward the surface of the WJP construction object, the high-pressure water flow containing a large number of bubbles passes through a narrow injection port formed in the nozzle. Large flow noise (elastic wave) is generated even if the material does not collapse. The PZT sensor provided in the nozzle also detects the flow noise. However, not all bubbles contained in the high-pressure water flow passing through the injection port are necessarily crushed after the water flow is injected from the nozzle. In Japanese Patent Laid-Open No. 6-47668, flow noise generated at a nozzle due to bubbles that do not collapse (bubbles that do not generate shock waves) is also detected. For this reason, even in Japanese Patent Laid-Open No. 6-47668, the effect of improving the residual stress in the WJP construction target cannot be confirmed with high accuracy.

  The objective of this invention is providing the water jet peening method and its apparatus which can confirm the improvement effect of the residual stress in a water jet peening execution target object more accurately.

  A feature of the present invention that achieves the above-described object is that a shock wave generated by collapsing bubbles contained in water jetted from a nozzle is detected by a plurality of shock wave detection devices arranged in the water, and a certain shock wave is detected. Based on the difference in shock wave detection time between the device and other shock wave detection devices, the shock wave generation position was obtained, and based on the shock wave generation position, it was set in a direction away from the surface of the water jet peening object. The purpose is to determine the frequency of occurrence of shock waves for each of a plurality of sections.

  Since the occurrence frequency of shock waves is determined for each of multiple sections set in the direction away from the surface of the water jet peening object, the frequency of occurrence of shock waves in any section in the direction away from the surface of the water jet peening object is high. I can understand. For this reason, the shock wave which has contributed to the improvement of the residual stress of the water jet peening object can be grasped, and the improvement effect of the residual stress in the water jet peening object can be confirmed with higher accuracy.

  The above-mentioned purpose is to detect a plurality of shock waves generated by crushing bubbles contained in water jetted from the nozzle by a plurality of shock wave detection devices arranged in the water, and one shock wave detection device and another shock wave. Obtain the shock wave generation position based on the difference in the detection time of the shock wave with the detection device, and obtain the energy of the multiple shock waves generated based on the detection signal of the shock wave detected by the multiple shock wave detection devices. This can also be achieved by determining the energy received by the water jet peening object by the plurality of shock waves based on the energy of the plurality of shock waves and the positions where the plurality of shock waves are generated.

  ADVANTAGE OF THE INVENTION According to this invention, the improvement effect of the residual stress in a water jet peening construction target object can be confirmed more accurately.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram of the water jet peening apparatus used for the water jet peening method of Example 1, which is a preferred embodiment of the present invention. It is a flowchart which shows the control and determination procedure at the time of using the water jet peening apparatus shown in FIG. It is explanatory drawing which shows an example of the display information displayed on the display apparatus shown in FIG. It is explanatory drawing which shows typically the form of the bubble in the water flow injected from the nozzle. It is explanatory drawing of the detection concept of the shock wave using two AE sensors, (A) is explanatory drawing which shows the example of arrangement | positioning of two AE sensors which detect a shock wave, (B) Two AE sensors were arrange | positioned It is explanatory drawing of the one-dimensional approximation model of the propagation path of a shock wave in the case. It is explanatory drawing of the detection concept of the shock wave using three AE sensors, (A) is explanatory drawing which shows the example of arrangement | positioning of three AE sensors which detect a shock wave, (B) Three AE sensors were arrange | positioned It is explanatory drawing of the one-dimensional approximation model of the propagation path of a shock wave in the case. It is explanatory drawing which shows an example of the display information which showed the generation frequency of the shock wave for every position from the surface of a structural member in the state in which the stress improvement effect of the structural member is acquired. It is explanatory drawing which shows an example of the display information which showed the generation frequency of the shock wave for every position from the surface of a structural member in the state where the stress improvement effect of the structural member is insufficient. It is a block diagram of the water jet peening apparatus used for the water jet peening method of Example 2 which is another Example of this invention. It is a flowchart which shows a part of control and determination procedure at the time of using the water jet peening apparatus shown in FIG. It is a flowchart which shows the remaining part of the control and determination procedure at the time of using the water jet peening apparatus shown in FIG. It is explanatory drawing which shows the waveform of the shock wave detected by the three AE sensors shown in FIG. It is an enlarged view of the waveform of each shock wave shown in FIG. It is explanatory drawing which shows an example of the display information which showed the generation frequency distribution of the shock wave in the state where the stress improvement effect was insufficient created with the display information creation apparatus shown in FIG. It is explanatory drawing which shows an example of the display information which showed the generation frequency distribution of the shock wave in the state with which the stress improvement effect was acquired created with the display information creation apparatus shown in FIG. It is explanatory drawing which shows the change of the shock wave generation frequency in the state in which the water jet peening method of Example 1 is performed. It is a block diagram of the water jet peening apparatus used for the water jet peening method of Example 3 which is another Example of this invention. It is a perspective view of the turntable vicinity of the water jet peening apparatus shown in FIG. It is an enlarged view of the moving apparatus provided with the nozzle of the water jet peening apparatus shown in FIG. It is an enlarged view near the nozzle of the water jet peening apparatus shown in FIG. It is a block diagram of the water jet peening apparatus used for the water jet peening method of Example 4 which is another Example of this invention. It is a block diagram of the signal processing apparatus of the water jet peening apparatus used for the water jet peening method of Example 5 which is another Example of this invention. It is explanatory drawing which shows an example of the display information which showed the generation frequency distribution of the shock wave in the state with which the stress improvement effect was acquired created with the display information creation apparatus shown in FIG. It is explanatory drawing which shows an example of the display information which showed the generation frequency distribution of the shock wave in the state where the stress improvement effect was insufficient created with the display information creation apparatus shown in FIG. It is a block diagram of the signal processing apparatus of the water jet peening apparatus used for the water jet peening method of Example 6 which is another Example of this invention. It is explanatory drawing which shows an example of the display information which showed the generation frequency distribution of the shock wave in the state with which the stress improvement effect was acquired created with the display information creation apparatus shown in FIG. It is explanatory drawing which shows an example of the display information which showed the generation frequency distribution of the shock wave in the state where the stress improvement effect is insufficient created with the display information creation apparatus shown in FIG. It is a block diagram of the signal processing apparatus of the water jet peening apparatus used for the water jet peening method of Example 7 which is another Example of this invention. It is explanatory drawing which shows an example of the display information which produced | generated with the display information creation apparatus shown in FIG. 28, and showed the generation frequency distribution of the shock wave in the state in which the stress improvement effect is acquired. It is explanatory drawing which shows an example of the display information which showed the generation frequency distribution of the shock wave in the state where the stress improvement effect was insufficient created with the display information creation apparatus shown in FIG. It is a block diagram of the signal processing apparatus of the water jet peening apparatus used for the water jet peening method of Example 8 which is another Example of this invention.

  The residual stress of the component due to WJP is not improved only by the impact force when the high-pressure water flow injected from the nozzle directly collides with the surface of the component, but the bubbles contained in the injected water flow are crushed. The shock wave generated in this way is greatly improved by colliding with the constituent members.

  The improvement of the residual stress of this component will be described in more detail. A high-pressure water stream ejected from a nozzle disposed in the water contains a large number of bubbles. The bubbles are not only contained in the high-pressure water stream ejected from the nozzle, but are also generated in the water stream ejected from the nozzle into the water. When a high-pressure water stream is ejected from nozzles placed in the water, a large number of vortices are generated by the shear force generated at the boundary between the static water around the nozzles and the water stream ejected from the nozzles. Local pressure fluctuations occur. At this time, bubbles are generated in a region where a negative pressure is locally generated.

  Bubbles contained in the high-pressure water flow at the time of injection from the nozzle and bubbles generated in the water flow after the injection grow under a negative pressure and contract under a positive pressure. When the positive pressure further increases, the generated bubbles are crushed. When a bubble collapses, a very large shock wave is emitted. This process of bubble generation, growth / shrinkage, and crushing is called cavitation. When cavitation occurs, a large shock wave is emitted, and the shock wave collides with the component member, whereby the tensile residual stress near the surface of the component member is improved to the compressive residual stress.

  FIG. 4 schematically shows a state from when bubbles are generated in the jetted water flow until they are crushed. High pressure water 38 is supplied from a pump (not shown) to the nozzle 6 disposed in the water 3. When the high-pressure water 38 is jetted into the water from the jet port 37 of the nozzle 6, a cavitation cloud 39 is generated in which a large number of minute bubbles are generated in the water to form a lump. When one or several bubbles are crushed in the generated plurality of cavitation clouds 39, several shock waves are emitted. When these shock waves repeatedly strike the surface of the component member, the residual stress existing near the surface of the component member is improved. When one or several bubbles are crushed and a shock wave is generated in the jetted water flow, a large number of bubbles existing around the bubble are swept away by the shock wave. For this reason, the vortex cavitation 40 in which the group of bubbles to be washed away is continuous is formed. Furthermore, a spot 41 that looks as if the bubble has disappeared because the bubble has been swept away is observed. In FIG. 4, 42 is a rough bubble.

  It is a shock wave generated by collapsing bubbles that brings about the stress improving effect of the constituent members. The inventors have found that the stress improvement effect is not due to the number of bubbles contained in the water stream ejected from the nozzle and the number of bubbles present in the water into which the water stream is ejected, but to the collapsed bubbles per unit time. (The frequency with which the bubbles collapse), that is, the number of shock waves generated per unit time (the frequency with which shock waves are generated). The inventors, in particular, accurately grasp the degree of improvement in residual stress near the surface of the component member by determining the number of shock waves generated per unit time for each position (distance) from the surface of the component member. I also found that I can do it. The present invention has been made based on these findings.

  The concept of the present invention based on these findings will be described using one specific example shown in FIG. The nozzle 6 and the support member 17 are attached to the moving device 19, and two AE sensors (shock wave detecting devices) 16A and 16B are installed at intervals in the axial direction of the nozzle 6 (see FIG. 5A). The nozzle 6 and the AE sensors 16A and 16B are disposed in the water, and the component 2 that is a WJP construction target is also disposed in the water. The nozzle 6 faces the surface of the component 2 on which WJP is applied. The AE sensor 16 </ b> A is disposed near the surface of the component member 2, and the AE sensor 16 </ b> B is disposed at a position slightly away from the surface of the component member 2 than the tip of the nozzle 6. Shock wave conversion plates 33A and 33B are provided on the support member 17 and attached to the front surfaces of the AE sensors 16A and 16B. As the shock wave detection device, a pressure sensor, an acceleration sensor, and an underwater microphone may be used in addition to the AE sensor.

  When the bubbles 35 contained in the high-pressure water stream 34 ejected from the nozzle 6 are crushed, a shock wave 36 is generated. The shock wave 36 is converted into a sound wave in the shock wave conversion plate 33A through the propagation path 43A and is transmitted to the AE sensor 16A. The shock wave 36 is converted into a sound wave in the shock wave conversion plate 33B through the propagation path 43B and transmitted to the AE sensor 16B. In this way, the AE sensors 16A and 16B each detect a shock wave and output a shock wave detection signal.

  The propagation speed of the shock wave 36 in water is V (m / s), and the sensor (for example, the AE sensor 16A) located near the position of the sound source (the position where the bubble 35 is crushed, that is, the generation position of the shock wave 36). The coordinate value in the Z direction is z1 (m) (see FIG. 5B), the coordinate value in the Z direction of a sensor (for example, the AE sensor 16B) located far from the position of the sound source is z2 (m), and a close position. T (s) is the propagation time of the shock wave to the AE sensor existing in the AE sensor, and T1 (s) is the time difference between the detection time of the shock wave in the AE sensor existing in the position close to the detection time of the shock wave. To do. A one-dimensional approximation model of a shock wave propagation path in the Z direction (axial direction of the nozzle 6) can be expressed as shown in FIG. 5B, and shock waves from a sound source to each shock wave detection device, for example, the AE sensors 16A and 16B. The propagation time of is expressed by the equations (1) and (2).

V × t = (z0−z1) (1)
V × (t + T1) = (z2−z0) (2)
t (s) cannot actually be measured, and the time difference T1 (s) can be measured. When the propagation velocity V (m / s) of the shock wave in water is known (for example, underwater sound velocity 1500 (m / s)), the coordinate value (position of the sound source in the Z direction) z0 of the sound source (M) is a shock wave generation position and can be calculated by the equation (3).

z0 = (z1 + z2) / 2−V × T1 / 2 (3)
When the propagation velocity V (m / s) of the shock wave in water (sound velocity in water) is unknown, by providing three shock wave detection devices, for example, AE sensors 16A, 16B and 16C, The generation position can be specified. The identification of the shock wave generation position in this case will be described with reference to FIG. An AE sensor 16 </ b> C is provided on the support member 17. A shock wave conversion plate 33C is provided on the support member 17 and attached in contact with the front surface of the AE sensor 16C (see FIG. 6A). The AE sensor 16 </ b> C is disposed in water and is disposed at a position farther from the surface of the component member 2 than the AE sensor B. The AE sensors 16A, 16B and 16C are arranged substantially in a straight line. The coordinate values z0, z1, and z2 in the Z direction represent distances from the surface in the Z direction, that is, the direction perpendicular to the surface of the component 2.

  The shock wave 36 generated by the collapse of the bubble 35 is detected by the AE sensor 16C via the propagation path 43C and the shock wave conversion plate 33C. The coordinate value in the Z direction of the sensor that detects the shock wave first (for example, the AE sensor 16A) is z1, the coordinate value in the Z direction of the sensor that detects the shock wave (for example, the AE sensor 16B) is z2, and the shock wave is 3 The coordinate value in the Z direction of the second detected sensor (for example, the AE sensor 16C) is set to z3 (see FIG. 6B). The coordinate value z3 in the Z direction also represents the distance from the surface in the direction perpendicular to the surface of the component 2. The sound velocity of the shock wave is Vz (m / s), the time when the shock wave generated by the sound source is detected by the closest sensor is t (s), and the time when the shock wave is detected by the second closest sensor from the position of the sound source is the closest. The time difference between the detection times of the shock waves in the sensor is T1 (s), and the time difference between the detection time of the shock waves in the sensor farthest from the position of the sound source and the detection time of the shock waves in the nearest sensor is T2 [s]. The one-dimensional approximation model of the shock wave propagation path at this time can be expressed as shown in FIG. 6B, and the propagation time of the shock wave from the sound source to each shock wave detection device, that is, the AE sensors 16A, 16B and 16C is (4 ), (5) and (6).

Vz × t = (z0−z1) (4)
Vz × (t + T1) = (z2−z0) (5)
Vz × (t + T2) = (z3−z0) (6)
t (s) cannot actually be measured, and the time differences T1 (s) and T2 (s) can be measured. The sound source position z0 (m) and the propagation velocity Vz [m / s] of the shock wave projected in the Z direction can be calculated based on the equations (7) and (8).

z0 = {z1 + z2-T1 × (z3-z2) / (T2-T1)} / 2 (7)
Vz = (z3-z2) / (T2-T1) (8)
As described above, by obtaining the position of the sound source from the surface of the component member that is the WJP construction object, that is, the generation position of the shock wave, The number of shock waves generated per unit time at the position (frequency of shock wave generation) can be obtained. For example, in a direction perpendicular to the surface of the component member 2, the space between this surface and the tip of the nozzle 6 is divided into a plurality of sections with a predetermined width, and the frequency of occurrence of shock waves is obtained for each of these sections.

  FIG. 7 and FIG. 8 both organize the relationship between the position from the surface and the frequency of shock wave generation in the direction perpendicular to the surface of the component 2 based on the determined shock wave generation position. The distribution of the frequency of occurrence of shock waves between the surface and the tip of the nozzle 6 in the direction perpendicular to the surface of the component 2 is shown. 7 and 8, the space between the surface of the component member 2 and the nozzle 6 is divided into 15 positions (sections) in a direction perpendicular to the surface of the component member 2.

  In the distribution example of the shock wave occurrence frequency shown in FIG. 7, two peaks are observed: an occurrence frequency peak 44 near the nozzle 6 and an occurrence frequency peak 45 near the surface of the component 2. . The position where the occurrence frequency peak 45 occurs is close to the surface of the constituent member 2, and the occurrence frequency peak 45 has a high occurrence frequency of shock waves. For this reason, in this distribution example of the shock wave generation frequency, the shock wave 36 generated by the collapse of the bubbles 35 contained in the jetted water flow 34 collides with the surface of the component member 2 efficiently. The residual stress existing near the surface is sufficiently improved.

  In the distribution example of the shock wave occurrence frequency shown in FIG. 8, the occurrence frequency peak 46 is observed at a position close to the nozzle 6, but the occurrence frequency peak is not observed at a position close to the surface of the component member 2. In this shock wave generation frequency distribution example, since the position of the generation frequency peak 46 is too far from the surface of the component member 2, the energy of each generated shock wave is weakened until it collides with the surface of the component member 2, The effect of improving the residual stress existing near the surface of the component 2 cannot be expected.

  When a distribution of shock wave occurrence frequency such that the shock wave occurrence frequency is small is obtained near the surface of the component member 2 as shown in FIG. 8, (a) the nozzle 6 is moved closer to the surface of the component member 2 and the nozzle 6 And (b) increase the pressure of water supplied to the nozzle 6 (increase the pressure of the water flow ejected from the nozzle 6), and (c) It is necessary to change the construction condition of WJP by performing at least one operation of increasing the flow rate of water supplied to the nozzle 6 (increasing the flow rate of the water flow ejected from the nozzle 6). Further, change of standoff, calculation of shock wave generation position, counting of shock waves generated at each position in the direction perpendicular to the surface of the component 2, and frequency of shock wave generation in the direction perpendicular to the surface of the component 2 By repeating the display of the distribution, it is possible to obtain the optimum standoff value when the injection conditions such as the pressure and flow rate of the injected water flow are made constant.

  Examples of the present invention will be described below.

  A water jet peening method according to embodiment 1, which is a preferred embodiment of the present invention, will be described with reference to FIGS.

  Before describing the water jet peening method of this embodiment, a water jet peening apparatus (hereinafter referred to as a WJP apparatus) 1 used in this embodiment will be described with reference to FIG. The WJP device 1 includes a nozzle 6, a water supply device 7, a nozzle scanning device 10, AE sensors (shock wave detection devices) 16A and 16B, a signal processing device 20, a nozzle scanning control device 27, and a pump control device 28.

  The nozzle scanning device 10 includes a column 11, moving devices 12, 14, 19, a first arm 13, and a second arm 15. The support | pillar 11 is attached to the base 32, and is extended in the up-down direction. A moving device 12 that moves in the vertical direction is movably provided on the column 11. A first arm 13 extending in the X direction in the horizontal direction is installed on the moving device 12. A moving device 14 that moves in the X direction along the first arm 13 is movably installed on the first arm 13. A second arm 15 extending in the Y direction perpendicular to the X direction in the horizontal direction is attached to the moving device 14. The moving device 19 is movably installed on the second arm 15, and the nozzle 6 is attached to the moving device 19. The base 32 is installed on the floor on which the water tank (container) 4 is installed.

  The water supply device 7 includes a high pressure pump 5, a water supply hose 8, and a high pressure hose 9. A water supply hose 8 is attached near the bottom of the water tank 4 and connected to the high-pressure pump 5. A high pressure hose 9 is connected to the high pressure pump 5 and the nozzle 6.

  The signal processing device 20 includes an A / D converter 21, a time difference calculation device 22, a position calculation device 23, a shock wave counting device 24, and a display information creation device 25. A time difference calculation device 22 is connected to the A / D converter 21 and the position calculation device 23. A shock wave counting device 24 connected to the position calculating device 23 is connected to the display information creating device 25. An A / D converter 21 and a display device 25 are connected to the display information creation device 25.

  AE sensors 16A and 16B, which are shock wave detection devices, are installed on a support member 17 that is attached to the moving device 19 and extends downward. The AE sensor 16B is disposed near the tip of the nozzle 6 in the axial direction of the nozzle 6, and the AE sensor 16A is disposed at a position away from the tip of the nozzle 6 in the axial direction. Shock wave conversion plates 33A and 33B are provided on the support member 17 and attached to the front surfaces of the AE sensors 16A and 16B. Amplifiers 18 A and 18 B are attached to the moving device 19. The AE sensor 16A is connected to the amplifier 18A, and the AE sensor 16B is connected to the amplifier 18B. The amplifiers 18A and 18B are connected to the A / D converter 21.

  An operation panel 29 is connected to the nozzle scanning control device 27 and the pump control device 28. A display device 26 is provided on the operation panel 29. A nozzle scanning control device 27 is connected to the moving devices 12, 14 and 19, and a pump control device 28 is connected to the high-pressure pump 5. A pressure gauge 31 and a flow meter 30 attached to the high pressure hose 9 are connected to the pump control device 28. The signal processing device 20 and the display device 26 are installed on the operation panel 29.

  The water jet peening method of this embodiment performed using the WJP apparatus 1 will be described. In the water jet peening method of this embodiment, the operation or processing of each step shown in FIG. 2 is performed.

  The water 3 is filled in the water tank 4, and the constituent member 2 that is a WJP construction target object is installed in the water 3 in the water tank 4. This component 2 is a component installed in a plant, for example, a nuclear plant to be constructed. Alternatively, the component 2 is a component of a nuclear plant that has undergone operation, and the WJP using the WJP device 1 is used for the component in a pool filled with water that is located in the management area of the nuclear plant. May be constructed. In FIG. 1, the component member 2 is schematically shown in a simplified shape.

  The nozzle is moved to the WJP start position (step S1). The operator inputs the position information for starting WJP, that is, the position information of the injection port of the nozzle 6 to the operation panel 29. The position information of the nozzle 6 is indicated by coordinate values in the X direction, the Y direction, and the Z direction (up and down direction). The nozzle scanning control device 27 drives the moving devices 12, 14, and 19 based on the input position information. The tip of the nozzle 6 is positioned at the coordinate value in the Z direction by the movement of the moving device 12, the coordinate value in the X direction by the movement of the moving device 14, and the coordinate value in the Y direction by the movement of the moving device 19. The distance between the nozzle 6 and the component member 2, that is, the distance at which the standoff is set is held by the coordinate value in the Z direction. The AE sensor 16A is disposed nearer the component member 2 in water than the AE sensor 16B.

  After the nozzle 6 is set at the WJP start position, the high-pressure pump is activated (step S2). A pump activation signal is input from the operation panel 29 to the pump control device 28 by the operation of the operator. At this time, the pump control device 28 starts the high-pressure pump 5. The high pressure pump 5 is operated under the initial operating conditions. When the high-pressure pump 5 is activated, the water 3 in the water tank 4 is guided to the high-pressure pump 5 through the water supply hose 8. The pump control device 28 controls the pressure and flow rate of water discharged from the high-pressure pump 5 based on the measured values of the pressure gauge 31 and the flow meter 30.

  The water 3 discharged from the high-pressure pump 5 is supplied to the nozzle 6 through the high-pressure hose 9 with the initial pressure and flow rate, and is jetted into the water in the water tank 4 from the nozzle 6 as a high-pressure water flow 34. A shock wave 36 is generated by the collapse of the bubbles 35 in the jetted water stream 34 in the water. The shock wave 36 collides with the component member 2 and is detected by the AE sensors 16A and 16B.

  The shock wave detection signals output from the AE sensors 16A and 16B that have detected the shock wave 36 are amplified by the amplifiers 18A and 18B, and then input to the A / D converter 21. The A / D converter 21 converts each shock wave detection signal, which is an analog signal, into a digital signal and outputs it to the time difference calculation device 22 and the display information creation device 25. The display information creating device 25 creates shock wave detection signal display information for each AE sensor 16A, 16B based on each shock wave detection signal. The shock wave detection signal display information is displayed on the display unit 38 of the display device 26 (see FIG. 3). In FIG. 3, “16A” indicates the shock wave detection signal output from the AE sensor 16A, and “16B” indicates the shock wave detection signal output from the AE sensor 16B. In these shock wave detection signals, a sharp waveform with a large wave height generated irregularly represents a shock wave 36 generated when the bubble 35 is crushed. The display information creation device 25 stores each shock wave detection signal output from the A / D converter 21 in a storage device (not shown) of the signal processing device 20.

  The generation position of the shock wave is calculated, and the shock wave is counted (step S3). The time difference calculation device 22 calculates a time difference T1 between a certain shock wave detection time in the AE sensor 16B and this shock wave detection time in the AE sensor 16A based on each input shock wave detection signal. The position calculation device 23 expresses the time difference T1, the coordinate value z1 (m) in the Z direction of the AE sensor 16A, the coordinate value z2 (m) in the Z direction of the AE sensor 16B, and the propagation of the shock wave in water. The velocity V (m / s) (for example, underwater sound velocity 1500 (m / s) is substituted to calculate the shock wave generation position z0. The coordinate value z1 (m), the coordinate value z2 (m), and the shock wave in water Is a known value, and the coordinate values z1 (m) and z2 (m) are Z-directions of the nozzle nozzle 6 input from the operation panel 29 by the operator in step S1. The shock wave generation position can be determined for all generated shock waves.

  The shock wave counting device 24 is in a direction perpendicular to the surface on which the WJP of the component member 2 is applied, and for each position (section) set by dividing the surface from the surface to the tip of the nozzle 6 by a predetermined width, Using the information on the occurrence position of each shock wave calculated by the position calculation device 23, the number of occurrences of shock waves is counted. The predetermined width is, for example, 10 mm, and each position is set every 10 mm from the surface of the component member 2 on which WJP is applied. The number of occurrences of each shock wave per unit time (frequency of occurrence of each shock wave) obtained for each position is input from the shock wave counting device 24 to the display information creating device 25. Although the measurement width of the shock wave generation position is 10 mm, since the tolerance of the proper stand-off range of WJP is wide, a sufficient stress improvement effect can be achieved even with an adjustment width of about 10 mm.

  The display information creation device 25 creates display information representing the frequency of occurrence of shock waves for each position in a direction perpendicular to the surface of the component member 2 on which WJP is applied. This display information indicates the distribution of shock wave occurrence frequency in the direction perpendicular to the surface of the component member 2 and is displayed on the display unit 39 of the display device 26. The display information creating device 25 stores the information on the occurrence position of each shock wave, the occurrence frequency of the shock wave for each position, and the distribution information of the shock wave occurrence frequency in the storage device.

  It is determined whether there is an effect of improving the residual stress on the WJP construction object (step S4). The operator views the information (distribution of shock wave occurrence frequency in the direction perpendicular to the surface of the component member 2) displayed on the display unit 39 of the display device 26, so that the tensile residual stress existing in the component member 2 is reduced. It can be determined whether the compressive residual stress is improved. When the distribution of the shock wave occurrence frequency displayed on the display unit 39 has the distribution shown in FIG. 7, the determination in step S4 is “Yes”, that is, “the effect of improving the residual stress is sufficient”. In the distribution shown in FIG. 7, a shock wave generation frequency peak 45 exists near the component 2, and the shock wave generation frequency at the generation frequency peak 45 is large. When the distribution of the shock wave generation frequency is the distribution shown in FIG. 8 where the peak 46 of the shock wave generation frequency exists at a position close to the nozzle 6, the determination in step S4 is “No”, that is, “improvement of residual stress”. The effect is insufficient. "

  It is determined whether the confirmation of the standoff change has been completed (step S5). The operator determines whether the confirmation of the standoff change has been completed. When this determination is “No”, the standoff is changed (step S6). The operator inputs the changed coordinate value in the Z direction from the operation panel 29 in order to change the standoff, for example, to shorten the standoff. The nozzle scanning control device 27 lowers the moving device 12 based on the coordinate value in the Z direction, and the tip of the nozzle 6 is positioned at a predetermined position in the Z direction.

  Thereafter, the water flow 34 is jetted from the nozzle 6, and the signal processing device 20 executes the process of step S <b> 3. When the determination in step S4 is “No” and the determination in step S5 is “Yes”, the operator has determined that a condition for improving the residual stress cannot be found only by changing the standoff. At this time, the operating condition of the high-pressure pump is changed (step S7). The operator operates the operation panel 29 to change the operating condition of the high pressure pump 5 (the set value of the discharge pressure of the high pressure pump 5 (or the set value of the discharge flow rate)). For example, the set value of the discharge pressure (or discharge flow rate) is increased. The pump control device 28 controls the high-pressure pump 5 based on the changed operating condition. Water whose pressure has been increased by the high-pressure pump 5 is jetted from the nozzle 6. When the process in step S3 is executed and the determination in step S4 is “Yes”, the preparation for WJP construction is completed.

  When the determination in step S4 is “Yes”, nozzle scanning is started (step S8). The nozzle 6 is scanned in the set direction. In this scanning, the operator inputs a nozzle scanning start position (hereinafter referred to as a scanning start position), a scanning direction (X direction or Y direction), and a nozzle scanning end position (hereinafter referred to as a scanning end position) to the operation panel 29. Done. When the nozzle scanning control device 27 inputs such information from the operation panel 29, it outputs a scanning start signal to the corresponding moving device (the moving device 14 or the moving device 19). For example, when the scanning direction input to the operation panel 29 by the operator is the X direction, the moving device 14 moves along the first arm 13 and moves the nozzle 6 from the scanning start position to the scanning end position in the X direction.

  The scanning start signal output from the nozzle scanning control device 27 is also input to the pump control device 28. The pump control device 28 drives the high-pressure pump 5 based on the scanning start signal. For this reason, while the nozzle 6 is moving in the X direction by the movement of the moving device 14, a high-pressure water flow 34 is jetted from the nozzle 6 toward the component member 2. While the nozzle 6 moves in the X direction, a shock wave 36 generated by collapsing the bubbles 35 in the jetted water flow 34 is sequentially applied to the surface of the component 2. Since the movement of the nozzle 6 is performed along one welded portion that exists in the component 2 and extends in the X direction, the shock wave 36 exists near the surface of the welded portion and its heat affected zone. The tensile residual stress is improved to the compressive residual stress.

  The AE sensors 16A and 16B also move in the X direction together with the nozzle 6. While moving, the AE sensors 16A and 16B detect the shock wave 36 and output a shock wave detection signal. As described above, these shock wave detection signals are amplified by the amplifiers 18A and 18B and then input to the A / D converter 21. The display information creation device 25 creates shock wave detection signal display information for each of the AE sensors 16A and 16B based on the digital signal of each shock wave detection signal output from the A / D converter 21. The shock wave detection signal display information is displayed on the display unit 38 of the display device 26 (see FIG. 3).

  Furthermore, while the nozzle 6 that jets the water flow 34 is moved, the generation position of the shock wave is calculated, and the shock wave is counted (step S9). The processing in step S9 is performed by the time difference calculation device 22, the position calculation device 23, the shock wave counting device 24, and the display information creation device 25 of the signal processing device 20, and is the same as the processing in step S3. The display information creating device 25 creates display information representing the shock wave occurrence frequency for each position in the direction perpendicular to the surface of the component member 2. This display information is displayed on the display unit 39 of the display device 26.

  When the nozzle reaches the scanning end position, scanning of the nozzle is stopped (step S10). When the nozzle 6 reaches the scanning end position in the X direction described above, the nozzle scanning control device 27 outputs a stop signal to the moving device 14. The moving device 14 is stopped by the output of the stop signal, and the scanning of the nozzle 6 in the X direction is completed. The nozzle scanning control device 27 inputs an output signal of an encoder (not shown) provided in the moving device 14, and determines that the nozzle 6 has reached the scanning end position in the X direction based on this output signal.

  It is determined whether there is an effect of improving the residual stress on the WJP construction object (step S11). The determination in step S11 is performed similarly to the determination in step S4. The operator sees the information (distribution of shock wave occurrence frequency in the direction perpendicular to the surface of the component member 2) displayed on the display unit 39 of the display device 26, so that the tensile residual stress existing in the structural member 2 is Determine whether the compressive residual stress has been improved. When the determination in step S11 is “Yes”, the high-pressure pump 5 is stopped (step S14). Based on the pump stop command input by the operator from the operation panel 29, the pump control device 28 stops the high-pressure pump 5. Thereby, construction of WJP along one welding part formed in component 2 is completed.

  When the determination in step S11 is “No”, the standoff (or the operating condition of the high pressure pump) is changed (step S12). The operator operates the operation panel 29 to change the coordinate value in the Z direction of the nozzle 6 (or the operating condition of the high pressure pump 5 (the set value of the discharge pressure or the discharge flow rate of the high pressure pump 5)). Then, the nozzle scanning direction is changed to the reverse direction (step S13). The operator operates the operation panel 26 to set the scan end position in a certain direction (for example, the X direction) set in step S8 as the scan start position, and the scan start position set in step S8 as the scan end position. Set.

  Thereafter, the scan in step S8 is performed. The nozzle scanning control device 27 moves the moving device 14 in the direction opposite to the previous time based on the position information set in step S13. The nozzle 6 injecting the high-pressure water stream is moved from the scanning start position set in step S13 to the scanning end position. When the nozzle 6 reaches the scanning end position, the scanning of the nozzle 6 is stopped (step S10). The operator sees the distribution of the shock wave occurrence frequency displayed on the display unit 39 of the display device 26, and makes the determination in step S11. When this determination is “Yes”, the operation of step S14 stops the high-pressure pump 5 as described above.

  In the component 2, when another welded part exists in the X direction and when a welded part also exists in the Y direction, scanning is sequentially started for each welded part and the heat affected part in step S8. Set the position and the scanning end position, and construct WJP sequentially. When the construction of WJP for all the welds and the like existing in the constituent member 2 is completed, the construction of WJP for the constituent member 2 is completed.

  In this embodiment, a high-pressure water stream 34 is ejected from the nozzle 6 and a shock wave 36 generated by collapsing bubbles 35 in the water stream 34 is applied to the surface of the component member 2 while WJP is applied to the component member 2. The AE sensors 16A and 16B detect the shock wave 36. The shock wave 36 is generated from the collapsed bubble 35 and is not generated from the bubble 35 that was not collapsed. Therefore, in the present embodiment, the AE sensors 16A and 16B detect the bubble 35 that generated the shock wave 36, that is, the bubble 35 that contributed to the WJP construction. The AE sensors 16A and 16B do not detect the bubbles 35 that are not crushed. By detecting the collapsed bubbles 35 that contributed to the WJP construction, the degree of improvement in the residual stress of the component 2 can be grasped with higher accuracy.

  In particular, in the present embodiment, based on the time difference T1 of the detection time of the shock wave 36 in each of the AE sensors 16A and 16B, the generation position of each shock wave 36 in the direction perpendicular to the surface of the component member 2 on which the WJP is applied is obtained. In addition, the number of shock waves generated is counted for each position set by dividing the distance from the surface to the tip of the nozzle 6 in the vertical direction, using the information on the position where each shock wave is generated. ing. Therefore, the occurrence frequency of the shock wave 36 can be obtained for each position set in the vertical direction, and the distribution of the occurrence frequency of the shock wave in the vertical direction can be grasped. Therefore, the improvement effect of the residual stress existing in the component 2 can be grasped with higher accuracy based on the position in the vertical direction where the peak of the shock wave occurrence frequency occurs and the occurrence frequency of the shock wave at this peak position. Can do. If the position of the peak of the shock wave occurrence frequency exists near the component 2 and the shock wave occurrence frequency at the peak position is equal to or higher than the set value of the occurrence frequency, there is an effect of improving the residual stress in the component 2. It will be.

  In the present embodiment, the improvement effect of the residual stress existing in the component member 2 can be grasped with higher accuracy. Therefore, when the improvement effect is insufficient, the operating conditions of the standoff or the high-pressure pump 5 are changed. The WJP can be reconstructed immediately.

  In the present embodiment, even when the nozzle 6 is scanned while jetting the water flow 34, the construction effect of WJP on the component 2 can be confirmed with higher accuracy.

  In this embodiment, the AE sensors 16 </ b> A and 16 </ b> B are attached not to the nozzle 6 but to the support member 17 provided in the moving device 19. For this reason, the detection of the elastic wave based on the flow vibration of the high-pressure water containing the bubbles passing through the injection port of the nozzle 6 by the AE sensors 16A and 16B is remarkably suppressed. This also contributes to the fact that the effect of improving the residual stress in the WJP construction object can be confirmed with higher accuracy.

  In particular, since the information on the distribution of shock wave occurrence frequency in the direction perpendicular to the surface of the component member 2 is displayed on the display device 21, the operator can easily grasp the effect of improving the residual stress in the WJP work target.

  Since the present embodiment can accurately confirm the effect of improving the residual stress in the WJP work target based on the frequency of occurrence of shock waves, the margin for evaluation for confirming the effect of improving the residual stress can be reduced. . For this reason, the capacity | capacitance of the high pressure pump 5 which supplies high pressure water to the nozzle 6 can be made small by the part which can make the margin small.

  When the capacity of the high-pressure pump 5 is not reduced, the moving speed of the nozzle 6 can be increased as much as the margin can be reduced. For this reason, the construction time of WJP can be further shortened.

  The nozzle scanning control device 27 and the pump control device 28 may be a single control device. The AE sensors 16A and 16B may be replaced with any of a pressure sensor, an acceleration sensor, and an underwater microphone, respectively.

  A water jet peening method according to embodiment 2, which is another embodiment of the present invention, will be described with reference to FIGS. 9, 10 and 11. FIG.

  Before explaining the water jet peening method of this embodiment, a WJP apparatus 1A used in this embodiment will be described with reference to FIG. The WJP apparatus 1A automates control of the high-pressure pump 5 and the nozzle scanning apparatus 10 by replacing the signal processing apparatus 20 with the signal processing apparatus 20A in the WJP apparatus 1 used in the first embodiment. In the present embodiment, one control device 47 that integrates the nozzle scanning control device 27 and the pump control device 28 used in the first embodiment is provided, and three AE sensors and three amplifiers are provided. Other configurations of the WJP apparatus 1A are the same as those of the WJP apparatus 1.

  In the WJP apparatus 1A, a configuration different from the WJP apparatus 1 will be described. The signal processing device 20A has a configuration in which a peak position calculation device 48 is added to the signal processing device 20 used in the first embodiment. A peak position calculation device 48 is connected to the shock wave counting device 24 and the display information creation device 25. A storage device 49 of the signal processing device 20A is connected to the A / D converter 21, the position calculation device 23, the shock wave counting device 24, the peak position calculation device 48, and the display information creation device 25.

  AE sensors 16A, 16B, and 16C are attached to the support member 17. A shock wave conversion plate 33C provided on the support member 17 is attached in contact with the front surface of the AE sensor 16C. The AE sensors 16A, 16B, and 16C are separately connected to the amplifiers 18A, 18B, and 18C provided in the moving device 19, and the amplifiers 18A, 18B, and 18C are connected to the A / D converter 21.

  The control device 47 is connected to the operation panel 29 and the storage device 49. The control device 47 is also connected to the high-pressure pump 5, the moving devices 12, 14 and 19, the flow meter 30 and the pressure gauge 31. The control device 47 has a threshold value for changing the operating condition of the high-pressure pump 5 (hereinafter referred to as an operating condition change threshold value) and a threshold value for determining an improvement effect of residual stress (hereinafter referred to as an improving effect determination threshold value) ), And the maximum value, minimum value, and change pitch of the standoff are stored in advance in a storage device (not shown) of the control device 47. These values are input from the operation panel 29 to the control device 47 by the operator. The operating condition change threshold value and the improvement effect determination threshold value are also stored in the storage device 49 from the control device 47.

  In the water jet peening method of the present embodiment, the controller 47 controls the steps S1, S2, S6 to S8, S10, S14, S16 to S19 and S21 to S26 described in FIG. 10 and FIG. Make a decision. The water jet peening method of the present embodiment performed using the WJP apparatus 1A will be described based on the steps described in FIGS.

  A component 2 of a nuclear power plant is installed in a water tank 4 filled with water 3 and disposed in water. This component 2 is a component installed in a plant, for example, a nuclear plant to be constructed. Moreover, you may construct WJP using the WJP apparatus 1 in the pool filled with water located in the management area of a nuclear power plant with respect to the component 2 of the nuclear power plant which experienced operation. Before the control of step S <b> 1 is performed, the operator starts the scan start position and the scan end position with respect to the plurality of welds formed in the component member 2 installed in the water tank 4 and extending in the X direction (or Y direction). Is input to the operation panel 29 in advance. Each of the input information of the scan start position and the scan end position is stored in the storage device of the control device 47.

  For example, it is assumed that WJP is applied to a certain welded portion formed in the component member 2 and extending in the X direction. When the operator inputs the WJP start command input to the operation panel 29 by the operator, the control device 47 starts the control in step S1. Under the control of step S1, the moving devices 12, 14 and 19 are driven, and the injection port of the nozzle 6 is positioned at the WJP start position with respect to the welded portion extending in the X direction. At this time, the tip of the nozzle 6 is separated from the surface of the component member 2 on which WJP is applied so that the standoff has a minimum value.

  The control device 47 executes the control in step S2. The high-pressure pump 5 is driven, and a high-pressure water stream 34 is jetted from the nozzle 6. The shock waves 36 generated by the collapse of the bubbles 35 included in the water flow 34 are detected by the AE sensors 16A, 16B, and 16C, respectively.

  After the high-pressure water stream 34 is ejected from the nozzle 6, the value of the monitoring index is calculated by the signal processing device 20A (step S15). The monitoring index in this embodiment is the peak position of the shock wave occurrence frequency, and the operating condition change threshold value and the improvement effect determination threshold value in this embodiment are threshold values for the peak position of the shock wave occurrence frequency. The processing content of step S15 will be specifically described below.

  The shock wave detection signals output from the AE sensors 16A, 16B, and 16C that have detected the shock wave 36 are amplified by the amplifiers 18A, 18B, and 18C, and then input to the A / D converter 21. The A / D converter 21 converts each shock wave detection signal of the analog signal into a digital signal, and outputs each shock wave detection signal converted into the digital signal to the display information creation device 25. The display information creation device 25 creates shock wave detection signal display information for each AE sensor 16A, 16B, 16C based on each shock wave detection signal. The shock wave detection signal display information is displayed on the display device 26 (see FIG. 12). In FIG. 12, “16A” is the shock wave detection signal output from the AE sensor 16A, “16B” is the shock wave detection signal output from the AE sensor 16B, and “16C” is the shock wave output from the AE sensor 16C. This is a detection signal. In these shock wave detection signals, a sharp waveform with a large wave height generated irregularly represents a shock wave 36 generated when the bubble 35 is crushed. Each shock wave detection signal converted from a digital signal output from the A / D converter 21 is stored in the storage device 49.

  FIG. 13 shows a sharp waveform portion having a large wave height shown in FIG. 12 with the horizontal axis (time axis) enlarged. The waveform 50a shown in FIG. 13 is included in the shock wave detection signal output from the AE sensor 16A when one shock wave 36 is detected. The waveform 50b is included in the shock wave detection signal output from the AE sensor 16B when the same single shock wave 36 is detected. The waveform 50c is included in the shock wave detection signal output from the AE sensor 16C when the same single shock wave 36 is detected. Since there is a time difference in the detection times of the waveforms 50a, 50b, 50c, the generation position of the one shock wave 36 can be specified as will be described later.

  Based on each shock wave detection signal output from the A / D converter 21, the time difference calculation device 22 calculates a time difference T1 (waveform 50b) between a certain shock wave detection time in the AE sensor 16B and this shock wave detection time in the AE sensor 16A. And the time difference T2 between the detection time of the shock wave in the AE sensor 16C and the detection time of the shock wave in the AE sensor 16A (time difference between the waveform 50c and the waveform 50a). The position calculation device 23 calculates the time differences T1 and T2, the coordinate value z1 (m) in the Z direction of the AE sensor 16A, the coordinate value z2 (m) in the Z direction of the AE sensor 16B, and the AE sensor. By substituting the coordinate value z3 (m) in the Z direction of 16C, the shock wave generation position z0 is calculated. The propagation velocity Vz of the shock wave in water can be obtained by substituting the time differences T1 and T2 and the coordinate values z2 and z3 into the equation (8).

  The shock wave counting device 24 uses, for each position (section) set in the direction perpendicular to the surface of the component member 2 on which WJP is applied, information on the occurrence position of each shock wave calculated by the position calculating device 23. Count the number of shock waves generated. The peak position calculation device 48 has the maximum occurrence frequency of shock waves based on the number of occurrences of each shock wave per unit time (occurrence frequency of each shock wave) obtained by the shock wave counting device 24. Is determined (hereinafter referred to as a peak position). The shock wave generation position calculated by the position calculation device 23, the shock wave generation frequency at each set position obtained by the shock wave counting device 24, and at least one shock wave obtained by the peak position calculation device 48 Each piece of information on the position where the occurrence frequency reaches the peak is stored in the storage device 49.

  The display information creation device 25 is obtained by the shock wave occurrence frequency, the operating condition change threshold value and the improvement effect determination threshold value, and the peak position calculation device 48 which are taken in from the storage device 49 and are set at the respective positions. Based on each information on the peak position, display information of the distribution of the frequency of occurrence of shock waves in the direction perpendicular to the surface of the component 2 on which the WJP is applied is created. This display information is displayed on the display device 26 and stored in the storage device 49. Examples of display information displayed on the display device 26 are shown in FIGS. Examples of the display information include an operating condition change threshold value 51 and an improvement effect determination threshold value 52. The operating condition change threshold value 51 and the improvement effect determination threshold value 52 used in this embodiment are for the peak position of the shock wave occurrence frequency, which is a monitoring index. Furthermore, the example of each display information shown by FIG.14 and FIG.15 contains the display symbol of the peak position of the shock wave generation frequency shown by 53A, 53B, and 53C. The operator can grasp the effect of improving the residual stress in the component member 2 by looking at the information displayed on the display device 26.

  After the injection of the water flow 34 from the nozzle 6 in step S2 is continued for a predetermined time, the control device 47 determines whether the standoff is maximum (step S16). When this determination is “No”, the standoff is increased by one pitch (step S6). The control device 47 outputs a 1 pitch increase command to the moving device 12 based on the stored standoff change pitch. The moving device 12 is moved based on the one pitch increase command, and the tip of the nozzle 6 is separated from the surface of the component 2 by one change pitch. The tip of the nozzle 6 is intermittently separated from the surface of the component 2 until the standoff reaches the maximum value. Each time the tip of the nozzle 6 is separated from the surface of the component member 2, the signal processing device 20A performs the process of step S15. Each information obtained by the A / D converter 21, the position calculation device 23, the shock wave counting device 24, and the peak position calculation device 48 is stored in the storage device 49 in association with the standoff value.

  When the determination in step S16 is “Yes”, the stand-off when the value of the monitoring index reaches the most desirable value is searched (step S17). In this embodiment, the most desirable value of the monitoring index is the peak position of the shock wave occurrence frequency that is closest to the surface of the component 2. The control device 47 has a stand-off corresponding to the most desirable monitoring index value, that is, the peak position of the most desirable shock wave occurrence frequency (the peak position of the shock wave occurrence frequency closest to the surface of the component 2). OFF) is retrieved from the storage device 49. It is determined whether the most desirable monitoring index value is less than or equal to the operating condition change threshold value (step S18). In the control device 47, it is determined whether the peak position of the shock wave occurrence frequency obtained by the peak position calculation device 48 is equal to or less than the operating condition change threshold value. When this determination result is “No”, it is determined that “the stress improvement effect is sufficiently increased, but if the injection is continued under the current conditions, the stress improvement effect may shift to an insufficient state”. The operating conditions of the high pressure pump are changed (step S7). The control device 47 changes the set value of the operating condition of the high-pressure pump 5 (the discharge pressure of the high-pressure pump 5 (or the set value of the discharge flow rate)). The setting value is changed by, for example, adding one pitch increase to the current discharge pressure setting value based on the one pitch increase of the discharge pressure stored in the storage device 49. The value with the minutes added becomes the new setting value. Then, the process of step S15 is performed, and when the determination of step S16 becomes “Yes”, steps S17 and S18 are executed.

  When the determination in step S18 is “Yes”, nozzle positioning is performed based on the searched standoff (step S19). The control device 47 controls the moving device 12 based on the searched standoff, and positions the tip of the nozzle 6 so that only the searched standoff is separated from the surface of the component 2. Thereafter, nozzle scanning is started (step S8). After the positioning of the tip of the nozzle 6 is completed, the control device 47 outputs a scanning start signal to the moving device 14 in order to apply WJP to, for example, a weld that extends in the X direction. The moving device 14 moves along the first arm 13 to move the nozzle 6 from the scanning start position to the scanning end position. The control device 47 also outputs the scanning start signal to the high-pressure pump 5 to drive the high-pressure pump 5. For this reason, the nozzle 6 is moved in the X direction while jetting the water flow 34 toward the component member 2. While the nozzle 6 moves in the X direction, a shock wave 36 generated by collapsing the bubbles 35 in the jetted water flow 34 is sequentially applied to the surface of the welded portion of the component member 2. By the shock wave 36, the tensile residual stress existing in the vicinity of the surface of the welded portion and the heat affected zone thereof is improved to the compressive residual stress.

  The AE sensors 16A, 16B, and 16C moving together with the nozzle 6 respectively detect the shock waves 29 propagating through the water 3, and output a plurality of shock wave detection signals. Specifically, the AE sensor 16A detects a sound wave generated in the shock wave conversion plate 33A due to the collision of the shock wave 36, and outputs a shock wave detection signal. The AE sensors 16B and 16C similarly output a shock wave detection signal.

  While the nozzle 6 is moving while jetting the water flow 34, the value of the monitoring index is calculated by the signal processing device 20A (step S20). Since the process of step S20 is the same as the process of step S15, detailed description is abbreviate | omitted. The shock wave detection signals output from the AE sensors 16A, 16B, and 16C are amplified by the amplifiers 18A, 18B, and 18C, and then input to the A / D converter 21. Here, based on each shock wave detection signal converted into a digital signal, the time difference calculation device 22 calculates time differences T1 and T2. The position calculation device 23 uses the time differences T1 and T2 to calculate the shock wave generation position in the same manner as in step S15. The shock wave counting device 24 uses the calculated information on the occurrence position of each shock wave for each position (section) set in the direction perpendicular to the surface of the component 2 on which the WJP is to be applied. Is counted. The peak position calculation device 48 obtains the peak position of the occurrence frequency of shock waves based on the occurrence frequency of each shock wave at each set position. The display information creation device 25 creates display information of the distribution of shock wave occurrence frequency and outputs it to the display device 26 as in step S15.

  It is determined whether the value of the monitoring index is equal to or less than the operating condition change threshold (step S21). While the nozzle 6 is moving toward the scanning end position while jetting the water stream 34, the control device 47 reads the latest peak position value from the storage device 49, and this peak position value changes the operating condition. Determine if it is below threshold. For example, when the peak position 53A shown in FIG. 14 is acquired from the storage device 49, the determination in step S21 is “No” because the peak position 53A is larger than the operating condition change threshold value. In this case, it is determined whether the value of the monitoring index is equal to or less than the improvement effect determination threshold value (step S22). The determination in step S22 performed by the control device 47 is “No” because the peak position 53A is larger than the improvement effect determination threshold value. The nozzle is moved to the scanning start position (step S24). When the determination in step S22 is “No”, there is a portion where the effect of improving the residual stress is insufficient in the component member 2 in the scanning process of the nozzle 6, that is, the tensile residual stress is changed to the compressive residual stress. It shows that there is a part that has not been improved sufficiently. For this reason, it is necessary to return the nozzle 6 to the scanning start position with respect to the welding part which is constructing WJP. The control device 47 outputs a return command to the moving device 14 when the determination in step S22 is “No”. The moving device 14 having received this command moves in the reverse direction, and returns the nozzle 6 to the scanning start position for the corresponding welded portion. After the nozzle 6 is returned to the scanning start position, the nozzle scanning speed (or the operating condition of the high-pressure pump) is changed (step S23). The control device 47 outputs a deceleration command to the moving device 14. The moving device 14 moves so that the scanning speed of the nozzle 6 becomes slow based on the deceleration command. For this reason, the number of shock waves colliding with the component member 2 increases, and the effect of improving the residual stress existing in the component member 2 increases. The controller 47 may increase the water discharge pressure (or water discharge flow rate) from the high-pressure pump 5 instead of decelerating the scanning speed of the nozzle 6. This also increases the effect of improving the residual stress of the component member 2.

  In step 24, the nozzle 6 is not at the scan start position, but at a position at which the determination in step 22 is “No” (a position where the peak position of the shock wave occurrence frequency is larger than the improvement effect determination threshold). The nozzle 6 may be returned to a slightly previous position, and the WJP may be restarted by slowing the scanning speed of the nozzle 6 from this position.

  If the determination in step S22 is “Yes”, the control in step 23 is executed by the control device 47.

  With the scanning speed of the nozzle 6 slowed down, the signal processing device 20A executes the process of step S20. When the control device 47 makes the determination in step S21, for example, it is assumed that the peak positions 53B and 53C shown in FIG. These peak positions are positions where the occurrence frequency of shock waves is maximized. When there are a plurality of peak positions, the determination in step S21 is “Yes” when the peak position closest to the component 2, that is, the peak position 53B is equal to or less than the operating condition change threshold value. For this reason, determination of step S21 in the control apparatus 47 becomes "Yes." The presence of a shock wave peak position below the operating condition change threshold means that there are many shock waves generated near the surface of the component 2 and that the effect of improving the residual stress of the component 2 is great. ing.

  When the determination in step S21 is “Yes”, it is determined whether the frequency of occurrence of shock waves is greater than or equal to a set value (step S25). In the control device 47, it is determined whether or not the shock wave occurrence frequency at the peak position of the shock wave occurrence frequency stored in the storage device 49 is equal to or higher than a set value. This set value is larger than the set value of the shock wave occurrence frequency for determining the residual stress improvement effect (hereinafter referred to as the second set value of the shock wave occurrence frequency), and changes the operating conditions of the high-pressure pump 5. This is a set value (hereinafter referred to as a first set value of shock wave occurrence frequency). The shock wave generation frequency at the peak position of the shock wave generation frequency is obtained by counting the number of shock waves generated at each position set in the direction perpendicular to the surface of the component 2 by the shock wave counting device 24.

  In step S25, instead of the shock wave generation frequency at the peak position of the shock wave generation frequency, the shock wave generation frequency generated between the position of the improvement effect determination threshold 52 and the surface of the component 2 is used. The frequency may be compared with the first set value of the corresponding shock wave occurrence frequency. The occurrence frequency of the shock wave generated between the position of the improvement effect determination threshold value 52 and the surface of the component 2 is determined by the shock wave counting device 24 between the position of the improvement effect determination threshold value 52 and the surface of the component member 2. It is obtained by counting the number of shock waves generated between the two.

  As shown in FIG. 16, when the shock wave generation frequency 55 at the peak position of the shock wave generation frequency becomes smaller than the first set value 56 of the shock wave generation frequency, the determination in step S25 becomes “No”. The determination in step S25 is performed while the nozzle 6 is moving toward the scanning end position. 16 shown in FIG. 16 is the second set value of the shock wave occurrence frequency. When the determination in step S25 is “No”, “the stress improvement effect is sufficiently increased, but if the injection is continued under this condition, the stress improvement effect may shift to an insufficient state”. The determination is made and the control in step S23 is performed to slow down the moving speed of the moving device 14. Instead of slowing down the moving speed, the discharge pressure (or discharge flow rate) of the high-pressure pump 5 may be increased. By reducing the moving speed of the moving device 14, that is, the scanning speed of the nozzle 6, the number of shock waves generated per unit moving distance of the nozzle 6 is increased, which substantially corresponds to an increase in the frequency of generating shock waves. To do.

  When the determination result of step S25 is “Yes”, the controller 47 determines whether the nozzle has reached the scanning end position (step S26). When the determination in step S26 is “No”, it is determined that nozzle scanning is continuing, and the determination or control after step S21 is executed in the control device 47. When the nozzle reaches the scanning end position and the determination in step S26 is “Yes”, the control in step S10 is executed.

  When the nozzle reaches the scanning end position, scanning of the nozzle is stopped (step S10). Based on an output signal from an encoder (not shown) provided in a motor (not shown) that moves the moving device 14, the control device 47 scans the end position of one weld where the nozzle 6 extends in the X direction. When it is determined that the movement has been reached, a drive stop signal is output to the motor to stop the movement of the moving device 14 and stop the scanning of the nozzle 6.

  The high pressure pump is stopped (step S14). The drive stop signal output from the control device 47 is input to the high pressure pump 5, and the high pressure pump 5 stops. Thereby, the WJP construction along one welded portion extending in the X direction of the component member 2 is completed. By this WJP construction, the tensile residual stress existing in the vicinity of the surface of the welded part and its heat-affected zone is improved to a compressive residual stress.

  In the case where another welded portion exists in the component member 2, as described above, WJP is applied to the welded portion.

  In the present embodiment, each effect produced in the first embodiment can be obtained. In the present embodiment, each moving device of the WJP device 1A and the high-pressure pump 5 can be automatically controlled by the control device 47 instead of the operator, so that the burden on the operator at the time of WJP construction is reduced. Further, in this embodiment, the effect of improving the residual stress existing in the component member 2 can be grasped with higher accuracy, so that the effect of improving the residual stress can be achieved by changing the standoff little by little. For this reason, the WJP can be constructed with the standoff set to the optimum standoff.

  A water jet peening method according to a third embodiment which is another embodiment of the present invention will be described with reference to FIGS. 17, 18, 19 and 20. The water jet peening method according to the present embodiment is performed on, for example, an in-reactor structure installed in a reactor pressure vessel of a boiling water nuclear plant. This in-furnace structure is, for example, a core shroud.

  The structure near the nuclear reactor of the boiling water nuclear power plant will be described with reference to FIG. A nuclear reactor 75 of a boiling water nuclear power plant includes a reactor pressure vessel (hereinafter referred to as RPV) 76, a core shroud 77, a core support plate 79, an upper lattice plate 80, and a jet pump 81. The core shroud 77, the core support plate 79, the upper lattice plate 80 and the jet pump 81 are installed in the RPV 76. In the core shroud 77 surrounding the core, a core support plate 79 located at the lower end of the core is installed, and an upper lattice plate 80 located at the upper end of the core is installed. A plurality of jet pumps 81 are disposed in an annular downcomer 82 formed between the RPV 76 and the core shroud 77.

  The WJP apparatus 1B used in the water jet peening method of the present embodiment has a configuration in which the nozzle scanning apparatus 10 in the WJP apparatus 1 used in the first embodiment is replaced with a nozzle scanning apparatus 10A. Other configurations of the WJP apparatus 1A are the same as those of the WJP apparatus 1.

  The nozzle scanning device 10A will be described. As shown in FIGS. 17, 18, and 19, the nozzle scanning device 10 </ b> A includes moving devices 58 </ b> A and 58 </ b> B, a post member 62, an elevating body 63, and a turntable 65. The turntable 65 is rotatably installed on an annular guide rail 66 installed on the upper surface of the upper flange 78 of the core shroud 5277. Although not shown, the turntable 65 is provided with a plurality of wheels that contact the upper surface of the guide rail 66. A motor (not shown) that rotates at least one wheel (not shown) is provided on the turntable 65. Moving devices 58A and 58B are installed on the turntable 65.

  The moving devices 58A and 58B having the same configuration will be described by taking the moving device 58A as an example. As shown in FIG. 19, the moving device 58 </ b> A includes a device main body 59, two arms 60, and a ball screw 72. Two arms 60 pass through the casing of the apparatus main body 59 and are slidably attached to the casing. Both ends of the two arms 60 are connected by connecting members 61A and 61B. A ball screw 72 passing through the casing of the apparatus main body 59 is rotatably attached to the connecting members 61A and 61B. Although not shown, a motor is installed in the casing of the apparatus main body 59, and a gear (not shown) attached to the rotation shaft of the motor meshes with a gear (not shown) that meshes with the ball screw 72. Yes. The gears are rotated by driving the motor, and the ball screw 72 is moved in the radial direction of the RPV 76. A post member 62 extending in the axial direction of the RPV 76 is attached to the connecting member 61B. The elevating body 63 is attached to the post member 62 so that it can move along the post member 62. A motor 64 that moves the elevating body 63 up and down is provided at the upper end of the post member 62.

  The nozzle 6, the AE sensors 16 </ b> A and 16 </ b> B, and the monitoring camera 67 are installed on the lifting body 63.

  In this embodiment, WJP is applied to the outer surface of the upper end portion of the core shroud 77. In this embodiment, the core shroud 77 is a WJP construction target object. After the operation of the boiling water nuclear power plant is stopped, the upper lid of the RPV 76 is removed, and the steam dryer and the steam separator installed in the RPV 76 are removed and carried out of the RPV 76. These are carried out using an overhead crane (not shown) in the reactor building where the RPV 76 is installed. When performing these removal and unloading operations, water 3 is filled in the reactor well 68 located immediately above the RPV 76.

  The guide rail 66 is transferred onto the upper flange 78 using the overhead crane and installed on the upper flange 78. The turntable 65 on which the moving devices 58 </ b> A and 58 </ b> B are installed is transported by the overhead crane and installed on the guide rail 66. The post member 62 to which the elevating body 63 is attached is installed in each of the moving devices 58A and 58B before the turntable 65 is conveyed. When the turntable 65 is installed on the guide rail 66, the post member 62 provided on each of the moving devices 58 </ b> A and 58 </ b> B is disposed in the downcomer 82.

  The high pressure pump 5 and the operation panel 29 are placed on the operation floor 69 in the reactor building, and the signal processing device 20, the nozzle scanning control device 27, the pump control device 28 and the display device 26 are provided on the operation panel 29. The operation floor 69 surrounds the reactor well 68. Two high-pressure hoses 9 connected to the high-pressure pump 5 are respectively attached to the moving devices 58A and 58B, and are separately connected to the nozzle 6 provided in the moving device 58A and the nozzle 6 provided in the moving device 58B. Yes.

  In the moving device 58A, the amplifiers 18A and 18B, which are waterproofed, are installed on the elevating body 63 (see FIG. 20). AE sensors 16A and 16B provided on the lifting body 63 of the moving device 58A are separately connected to the amplifiers 18A and 18B. Two signal lines 70 separately connected to the amplifiers 18A and 18B are connected to the A / D converter 21 of one signal processing device 20. The display information creation device 25 of the signal processing device 20 is connected to the display device 26.

  Also in the moving device 58 </ b> B, amplifiers 18 </ b> A and 18 </ b> B that are waterproofed are installed on the lifting body 63. AE sensors 16A and 16B provided on the lifting body 63 of the moving device 58B are separately connected to the amplifiers 18A and 18B. Two signal lines 70 separately connected to the amplifiers 18A and 18B are connected to the A / D converter 21 of the other signal processing device 20. The display information creation device 25 of the signal processing device 20 is connected to another display device 26.

  A control signal line 71 connected to the control device 22 is provided on the motor 64 provided in each of the moving devices 58A and 58B, the motor provided in the casing of the device main body 59, and the turntable 65. Are connected to motors that rotate the wheels. Each motor is provided with an encoder (not shown), and each encoder detects a moving distance of a member moved by the motor, that is, a position after the member moves.

  Also in the water jet peening method of the present embodiment, each operation or process shown in FIG. In the core shroud 77, there are a plurality of welds extending in the axial direction in the circumferential direction of the core shroud 77, and there are a plurality of welds extending in the circumferential direction in the axial direction of the core shroud 77. In the present embodiment, WJP is applied along these welds.

  For example, it is assumed that WJP is applied along a certain welded portion extending in the circumferential direction of the core shroud 77. In step S1, each nozzle 6 provided in the moving devices 58A and 58B is moved to the WJP start position. The operator inputs positional information of the core shroud 77 in the circumferential direction, axial direction, and radial direction from the operation panel 29. The control device 22 drives three motors provided in the WJP device 1A based on the position information, and positions the nozzle 6 at a scanning start position designated so as to face the one welded portion. The ball screw 72 is rotated by driving a motor provided in each device main body 59 of the moving devices 58A and 58B, and each post member 62 is moved in the radial direction of the core shroud 77. By this movement of the post member 62, the distance between the nozzle 6 and the outer surface which is the WJP construction surface of the core shroud 77, that is, the standoff is set to the set value. By driving the motor 64, the elevating body 63 moves along the post member 62 in the axial direction of the core shroud 77, and the nozzle 6 is positioned at a predetermined position in the axial direction of the core shroud 77.

  Thereafter, the operation of step S2 is executed. The high-pressure pump 5 is driven, and the pressurized high-pressure water is supplied through the high-pressure hose 9 to each nozzle 6 provided in the moving devices 58A and 58B. High pressure water is jetted from each nozzle 6 toward the outer surface of the welded portion of the core shroud 77 in the vicinity of the upper grid plate 80 at the initial pressure and flow rate. Shock waves 36 generated by the collapse of the bubbles 35 contained in the jetted water flow are detected by the AE sensors 16A and 16B. The shock wave detection signals output from the AE sensors 16A and 16B by the detection of the shock wave are input to the A / D converter 21. In each signal processing device 20, the processing in step S3 is performed in the same manner as in the embodiment. Display information that is generated by the display information generating device 25 and that represents the shock wave frequency for each position in the direction perpendicular to the surface of the component 2 is displayed on the display device 26.

  The determination in step S4 is performed by the operator as in the first embodiment. When the determination in step S4 is “No”, it is determined that “the effect of improving the residual stress is insufficient”, and the determination in step S5 is performed. When this determination is “No”, the standoff is changed in step S6. The operator inputs the coordinate value in the radial direction of the RPV 76 changed from the operation panel 29 in order to change the standoff, that is, to shorten the standoff. The nozzle scanning control device 27 drives the motor provided in the device main body 59 to rotate the ball screw 72 based on the coordinate values in the radial direction. As a result, the nozzle 6 is moved in the radial direction of the RPV 76 and the nozzle 6 is positioned in the radial direction.

  When the determination in step S5 is “Yes”, the discharge pressure (or discharge flow rate) of the high-pressure pump 5 is increased in step S7.

  In step S3, for each position (section) set in a direction perpendicular to the surface of the component member 2 on which WJP is applied, the number of generated shock waves is calculated using information on the calculated occurrence positions of the respective shock waves. Counting is performed, and display information of the distribution of shock wave occurrence frequency in the direction perpendicular to the surface of the component 2 is created. This display information is displayed on the display device 26. When the determination in step S4 is “Yes”, nozzle scanning is started (step S8).

  Each nozzle 6 provided in the moving devices 58 </ b> A and 58 </ b> B moves along a certain welded portion extending in the circumferential direction of the core shroud 77 while jetting a high-pressure water flow. This movement is performed by turning the turntable 65 along the guide rail 66 under the control of the nozzle operation control device 27. WJP for the welded portion and the heat affected zone is applied. In the present embodiment, since the two nozzles 6 are positioned in opposite directions of 180 °, when each nozzle 6 moves in the circumferential direction, for example, 190 °, the operation in step S10 is performed, and the nozzle 6 is scanned. Stopped. While the nozzle 6 is being scanned in the circumferential direction of the core shroud 77, the processing of step S9 is performed by each signal processing device 20.

  The determination in step S11 is performed based on the display information of the distribution of shock wave occurrence frequency obtained by the process in step S9 and displayed on the display device 26. When the determination in step S11 is “No”, it is determined that “the effect of improving the residual stress is insufficient”, and the control in step S12 is changed from the operation panel 29 by the operator. Is performed by the nozzle scanning control device 27 on the basis of the operating conditions). Then, the nozzle scanning direction is changed to the reverse direction (step S13). The operator operates the operation panel 29 to set the scan end position in a certain direction (for example, circumferential direction) set in step S8 as the scan start position, and the scan start position set in step S8 as the scan end position. Set. Thereafter, the scanning in step S8 is performed in the reverse direction. When the nozzle 6 reaches the scanning end position, the scanning of the nozzle 6 is stopped (step S10).

  The WJP is similarly applied to another welded portion formed in the core shroud 52 in the circumferential direction and a welded portion formed in the core shroud 52 in the axial direction.

  Also in this embodiment, each effect produced in the first embodiment can be obtained.

  A water jet peening method according to embodiment 4, which is another embodiment of the present invention, will be described with reference to FIG. The water jet peening method according to the present embodiment is performed on an in-furnace structure installed in an RPV of a boiling water nuclear plant, for example. This in-furnace structure is, for example, a core shroud.

  The WJP apparatus 1C used in the water jet peening method of the present embodiment is the same as that of the WJP apparatus 1B used in the third embodiment, in which the signal processing device 20, the nozzle scanning control device 27, and the pump control device 28 are used in the second embodiment. The configuration is changed to the device 20 </ b> A and the control device 47. Other configurations of the WJP apparatus 1C are the same as those of the WJP apparatus 1B. As in the second embodiment, the control device 47 executes control or determination of each of steps S1, S2, S6 to S8, S10, S14, S16 to S19, and S21 to S26 described in FIG. 10 and FIG. To do.

  As in the second embodiment, the control device 47 stores the operating condition change threshold value, the improvement effect determination threshold value, the standoff maximum value, the minimum value, and the change pitch in the storage device of the control device 47 in advance. doing.

  Also in the water jet peening method of the present embodiment, each control or process shown in FIGS. 10 and 11 is executed as in the second embodiment. In this embodiment, WJP is applied along a plurality of welds formed in the core shroud 77. For example, WJP is applied along a certain welded portion extending in the circumferential direction of the core shroud 77.

  In step S1, the control device 47 controls the moving devices 58A and 58B, respectively, similarly to the third embodiment, and positions the nozzles 6 provided in both moving devices at predetermined positions. In step S2, the high-pressure pump 5 is driven, and a high-pressure water stream 34 is ejected from each nozzle 6. In step S15, as in the second embodiment, the AE sensors 16A, 16B, and 16C each detect the shock wave 36, and the peak position of the occurrence frequency of the shock wave is obtained by each signal processing device 20A. The determination in step S16, the search in step S17, the determination in step S18, and the control in steps S6 and S19 are performed by the control device 47 as in the second embodiment. The control in steps S6 and S19 is performed by driving a motor provided in each device main body 59 of each of the moving devices 58A and 58B to rotate the ball screw 72.

  After the control in step S19 is executed, nozzle scanning is started (step S8). In order to apply WJP to one weld that extends in the circumferential direction, the control device 47 outputs a scanning start signal to the nozzle scanning device 10A. Based on this scanning start signal, the turntable 65 is turned along the guide rail 66. The two nozzles 6 move along one weld extending in the circumferential direction while jetting the water flow 34. While the nozzle 6 is moving, in step S20, as in step S15, the signal processing device 20A obtains the peak position of the occurrence frequency of shock waves and the like.

  Similarly to the second embodiment, the control device 47 performs the determination in step S21. When the determination in step S21 is “No”, “the stress improvement effect is sufficiently improved, but the injection is performed under the same conditions. If it is continued, there is a possibility that the stress improvement effect may shift to an insufficient state ”, and the determination of step S22 is performed. The monitoring index in this embodiment is a peak position. When the determination in step S22 is “No”, there is a portion where the effect of improving the residual stress is insufficient in the component member during the scanning of the nozzle 6, that is, the tensile residual stress is sufficiently improved to the compressive residual stress. It indicates that there is a part that is not. For this reason, the drive of the turntable 65 is controlled by the control apparatus 47 similarly to Example 2, and control of step S24, S23 is performed. When the determination in step S21 is “Yes”, the determinations in steps S25 and S26 are performed. When the determination in step S26 is "Yes", the control in steps S10 and S14 is executed, and the construction of WJP for one welded portion is completed.

  The WJP is similarly applied to another welded portion formed in the core shroud 52 in the circumferential direction and a welded portion formed in the core shroud 52 in the axial direction.

  Also in this embodiment, each effect produced in the third embodiment can be obtained. In the present embodiment, as in the second embodiment, an optimal standoff can be selected and WJP can be applied.

  Examples 3 and 4 can be applied to the construction of WJP for other in-core structures in the RPV 76 of the boiling water nuclear power plant.

  A water jet peening method according to embodiment 5 which is another embodiment of the present invention will be described with reference to FIG. The WJP apparatus 1D used in the water jet peening method of the present embodiment has a configuration in which the signal processing apparatus 20A in the WJP apparatus 1A used in the second embodiment is replaced with the signal processing apparatus 20B shown in FIG. Other configurations of the WJP apparatus 1D are the same as the configuration of the WJP apparatus 1A. The signal processing device 20B has a configuration in which the peak position calculation device 48 of the signal processing device 20A is replaced with an average value calculation device 85. The other configuration of the signal processing device 20B is the same as that of the signal processing device 20A. The average value calculation device 85 is connected to the shock wave counting device 24, the display information creating device 25, and the storage device 49.

  Also in the water jet peening method of this embodiment, the control or determination of each step of steps S1, S2, S6 to S8, S10, S14, S16 to S19 and S21 to S26 described in FIG. 10 and FIG. 47, and the processing of steps S15 and S20 is executed by the signal processing device 20B. Under the control of the control device 47, WJP is applied to the component member 2 as in the second embodiment.

  In the water jet peening method of the present embodiment, portions different from the second embodiment will be described. The average value calculating device 85 calculates the average value of the shock wave occurrence frequency based on the number of occurrences of each shock wave per unit time (occurrence frequency of each shock wave) obtained by the shock wave counting device 24. Ask for. The average value of the shock wave occurrence frequency is an average value for all the set positions. This average value is stored in the storage device 49.

  The display information creation device 25 is obtained by the shock wave occurrence frequency, the operating condition change threshold value and the improvement effect determination threshold value, and the average value calculation device 85 at each set position fetched from the storage device 49. Based on each piece of information on the average value of the shock wave occurrence frequency, display information of the distribution of the shock wave occurrence frequency in the direction perpendicular to the surface of the component 2 on which the WJP is applied is created. This display information is displayed on the display device 26 and stored in the storage device 49. Examples of display information displayed on the display device 26 are shown in FIGS. Examples of the display information include an operating condition change threshold value 90 and an improvement effect determination threshold value 91. The operating condition change threshold value 90 and the improvement effect determination threshold value 91 used in this embodiment are for the average value of the shock wave occurrence frequency. Furthermore, the example of each display information shown by FIG.23 and FIG.24 contains the display symbol of the average value of the shock wave generation frequency shown by 92A and 92B.

  The monitoring index in this embodiment is an average value of the shock wave occurrence frequency. Each determination of steps S18, S21, and S22 of the present embodiment is performed using the average value of the shock wave occurrence frequency fetched from the storage device 49.

  In the present embodiment, each effect produced in the second embodiment can be obtained.

  In the WJP apparatus 1C, the signal processing apparatus 20A can be changed to the signal processing apparatus 20B used in this embodiment. The water jet peening method of the fourth embodiment may be executed using the WJP apparatus 1C in which the signal processing apparatus 20A is replaced with the signal processing apparatus 20B. In this case, the effect produced in the fourth embodiment can be obtained.

  A water jet peening method according to embodiment 6, which is another embodiment of the present invention, will be described with reference to FIG. The WJP apparatus 1E used in the water jet peening method of the present embodiment has a configuration in which the signal processing apparatus 20A in the WJP apparatus 1A used in the second embodiment is replaced with a signal processing apparatus 20C shown in FIG. Other configurations of the WJP apparatus 1E are the same as the configuration of the WJP apparatus 1A. The signal processing device 20C has a configuration in which the shock wave counting device 24 of the signal processing device 20A is replaced with a shock wave counting device 24A, and a scanning distance conversion device 86 is further added. The other configuration of the signal processing device 20C is the same as that of the signal processing device 20A. The shock wave counting device 24 </ b> A is connected to the scanning distance conversion device 86 and the storage device 49. The scanning distance conversion device 86 is connected to the display information creation device 25 and the storage device 49.

  Also in the water jet peening method of this embodiment, the control or determination of each step of steps S1, S2, S6 to S8, S10, S14, S16 to S19 and S21 to S26 described in FIG. 10 and FIG. 47, and the processing of steps S15 and S20 is executed by the signal processing device 20C. Under the control of the control device 47, WJP is applied to the component member 2 as in the second embodiment.

  In the water jet peening method of the present embodiment, portions different from the second embodiment will be described. Similarly to the second embodiment, the shock wave counting device 24A uses the information on the position where each shock wave is generated for each position (section) set in the direction perpendicular to the surface of the component 2 to generate the shock wave generation frequency. Ask for. Further, the shock wave counting device 24A uses the shock wave generation frequency for each set position (section) to determine the effective per unit time generated between the position of the threshold 93 and the surface of the component member 2. The frequency of occurrence of a shock wave (hereinafter referred to as the first effective shock wave frequency) is obtained. The generation frequency of the first effective shock wave is stored in the storage device 49 and input to the scanning distance conversion device 86. The scanning distance conversion device 86 converts the first effective shock wave generation frequency output from the shock wave counting device 24A into an effective shock wave generation frequency per unit scanning distance of the nozzle 6 (hereinafter referred to as a second effective shock wave generation frequency). To do.

  The operator inputs a display information selection command to the operation panel 29 before construction of WJP. This display information selection command is input from the operation panel 29 to the display information creation device 25. The display information creation command is either (a) creation of display information using the first effective shock wave occurrence frequency, or (b) creation of display information using the second effective shock wave occurrence frequency.

  It is assumed that, for example, creation of display information (a) is selected by the display information creation command. The display information creating device 25 is configured based on the information on the occurrence frequency of shock waves per unit time at each set position fetched from the storage device 49, the threshold 93, and the first effective shock wave occurrence frequency. Display information of the distribution of the frequency of occurrence of shock waves in the direction perpendicular to the surface of the member 2 on which WJP is applied is created. This display information is displayed on the display device 26 and stored in the storage device 49. Examples of display information displayed on the display device 26 are shown in FIGS. These display information examples include a threshold value 93. Furthermore, the example of each display information shown by FIG.26 and FIG.27 contains the value of the 1st effective shock wave generation frequency.

  26 and 27, the shock wave generated at the position on the surface side of the structural member 2 from the position of the threshold value 93 is an effective shock wave that contributes to the improvement of the residual stress of the structural member 2. Further, the shock wave generated at the position on the nozzle 6 side from the position of the threshold value 93 is an invalid shock wave that does not contribute much to the improvement of the residual stress of the structural member 2. The first and second effective shock wave generation frequencies are effective shock wave generation frequencies that contribute to the improvement of residual stress. The threshold value 93 is determined by confirming the boundary between a region where an effective shock wave is generated and a region where an invalid shock wave is generated by an experiment or the like.

  When the creation of display information in (b) is selected, in the example of each display information in FIG. 26 and FIG. 27, the horizontal axis indicates the shock wave occurrence frequency per unit scanning distance, and the second effective shock wave occurrence frequency. The value of is included.

  The monitoring index in this embodiment differs when (a) creation of display information is selected and when (b) creation of display information is selected. When (a) is selected, the monitoring index is the first effective shock wave occurrence frequency, and the operating condition change threshold value and the improvement effect determination threshold value are respectively for the first effective shock wave occurrence frequency. When (b) is selected, the monitoring index is the second effective shock wave occurrence frequency, and the operating condition change threshold value and the improvement effect determination threshold value are respectively for the second effective shock wave occurrence frequency.

  Since (a) is selected, each determination of steps S18, S21, and S22 of the present embodiment is performed using the first effective shock wave occurrence frequency fetched from the storage device 49. When (b) is selected, the respective determinations in steps S18, S21 and S22 of this embodiment are made using the second effective shock wave occurrence frequency fetched from the storage device 49.

  In the present embodiment, each effect produced in the second embodiment can be obtained. When effective shock wave generation frequency per unit scanning distance is used, the improvement effect of residual stress in the WJP work target can be confirmed more accurately than when effective shock wave generation frequency per unit time is used. be able to.

  In the WJP apparatus 1C, the signal processing apparatus 20A can be changed to the signal processing apparatus 20C used in this embodiment. The water jet peening method of the fourth embodiment may be executed using the WJP apparatus 1C in which the signal processing apparatus 20A is replaced with the signal processing apparatus 20C. In this case, the effect produced in the fourth embodiment can be obtained.

  A water jet peening method according to embodiment 7, which is another embodiment of the present invention, will be described with reference to FIG. The WJP apparatus 1F used in the water jet peening method of the present embodiment has a configuration in which the signal processing apparatus 20A in the WJP apparatus 1A used in the second embodiment is replaced with the signal processing apparatus 20D shown in FIG. The other configuration of the WJP apparatus 1F is the same as that of the WJP apparatus 1A. The signal processing device 20D has a configuration in which the shock wave counting device 24 of the signal processing device 20A is replaced with a shock wave counting device 24B, and a scanning distance conversion device 86 is further added. The other configuration of the signal processing device 20C is the same as that of the signal processing device 20A. The shock wave counting device 24B is connected to the scanning distance converting device 86 and the storage device 49. The scanning distance conversion device 86 is connected to the display information creation device 25 and the storage device 49.

  Also in the water jet peening method of this embodiment, the control or determination of each step of steps S1, S2, S6 to S8, S10, S14, S16 to S19 and S21 to S26 described in FIG. 10 and FIG. 47, and the processing of steps S15 and S20 is executed by the signal processing device 20D. Under the control of the control device 47, WJP is applied to the component member 2 as in the second embodiment.

In the water jet peening method of the present embodiment, portions different from the second embodiment will be described. Similarly to the second embodiment, the shock wave counting device 24B uses the information on the position where each shock wave is generated for each position (section) set in the direction perpendicular to the surface of the component member 2 to generate a unit per unit time. Find the frequency of shock waves. Furthermore, the shock wave counting device 24 </ b> A corrects the occurrence frequency of shock waves per unit time for each set position based on the distance from the surface of the component member 2. When the distance between the surface of the component 2 and the set position is L, and the number of shock waves generated at the set position is n, the corrected shock wave generation frequency per unit time at the set position The SF (hereinafter referred to as the first corrected shock wave occurrence frequency) is obtained by n / L ² . The first corrected shock wave occurrence frequency is stored in the storage device 49 and input to the scanning distance conversion device 86. The scanning distance conversion device 86 converts the first corrected shock wave generation frequency output from the shock wave counting device 24B into a corrected shock wave generation frequency per unit scanning distance of the nozzle 6 (hereinafter referred to as a second corrected shock wave generation frequency).

  Also in the present embodiment, as in the sixth embodiment, the display information selection command is input from the operation panel 29 to the display information creating device 25. The display information creation command is either (c) creation of display information using the first corrected shock wave occurrence frequency or (d) creation of display information using the second corrected shock wave occurrence frequency.

  It is assumed that, for example, creation of display information (c) is selected by the display information creation command. The display information creation device 25 calculates the WJP of the component 2 based on the information on the occurrence frequency of the shock wave per unit time and the first corrected shock wave occurrence frequency at each set position fetched from the storage device 49. Display information on the distribution of shock wave frequency in the direction perpendicular to the surface to be constructed. This display information is displayed on the display device 26 and stored in the storage device 49. Examples of display information displayed on the display device 26 are shown in FIGS. 29 and 30. In the example of the display information described in FIGS. 29 and 30, the horizontal axis represents the corrected shock wave occurrence frequency per unit time. In FIG. 29, 94A shows the corrected shock wave generation frequency for each distance L from the surface of the component member, and 95A shows the corrected shock wave generation frequency 98A when all L are integrated. In FIG. 30, 94B shows the corrected shock wave generation frequency for each distance L from the surface of the component member, and 95B shows the corrected shock wave generation frequency 98B when all Ls are integrated. Further, the display information examples 95A and 95B include an operating condition change threshold value 97 and an improvement effect determination threshold value 98, respectively.

  The monitoring index in the present embodiment is different when the creation of display information (c) is selected and when the creation of display information (d) is selected. When (c) is selected, the monitoring index is the first corrected shock wave occurrence frequency, and the operating condition change threshold value and the improvement effect determination threshold value are respectively for the first corrected shock wave occurrence frequency. When (d) is selected, the monitoring index is the second corrected shock wave occurrence frequency, and the operating condition change threshold value and the improvement effect determination threshold value are respectively for the second corrected shock wave occurrence frequency.

  Since (c) is selected, each determination of steps S18, S21, and S22 of this embodiment is performed using the first corrected shock wave occurrence frequency fetched from the storage device 49. When (d) is selected, each determination of steps S18, S21, and S22 of this embodiment is performed using the second corrected shock wave occurrence frequency fetched from the storage device 49.

  In the present embodiment, each effect produced in the second embodiment can be obtained. When the corrected shock wave generation frequency per unit scanning distance is used, the improvement effect of the residual stress in the WJP work target can be confirmed with higher accuracy than when the corrected shock wave generation frequency per unit time is used. it can.

  In the WJP apparatus 1C, the signal processing apparatus 20A can be changed to the signal processing apparatus 20D used in this embodiment. The water jet peening method according to the fourth embodiment may be executed using the WJP apparatus 1C in which the signal processing apparatus 20A is replaced with the signal processing apparatus 20D. In this case, the effect produced in the fourth embodiment can be obtained.

  A water jet peening method according to embodiment 8, which is another embodiment of the present invention, will be described with reference to FIG. The WJP apparatus 1G used in the water jet peening method of the present embodiment has a configuration in which the signal processing apparatus 20A in the WJP apparatus 1A used in the second embodiment is replaced with the signal processing apparatus 20E shown in FIG. The other configuration of the WJP apparatus 1G is the same as that of the WJP apparatus 1A. The signal processing device 20E has a configuration in which the shock wave counting device 24 and the peak position calculation device 48 are removed from the signal processing device 20A, and a first energy calculation device 87, a second energy calculation device 88, and a scanning distance conversion device 86 are added. Have. The other configuration of the signal processing device 20E is the same as that of the signal processing device 20A. The first energy calculation device 87 is connected to the A / D converter 21 and the second energy calculation device 88. The second energy calculation device 88 is connected to the position calculation device 23, the scanning distance conversion device 86, and the storage device 49. The scanning distance conversion device 86 is connected to the display information creation device 25 and the storage device 49.

  Also in the water jet peening method of this embodiment, the control or determination of each step of steps S1, S2, S6 to S8, S10, S14, S16 to S19 and S21 to S26 described in FIG. 10 and FIG. 47, and the processing of steps S15 and S20 is executed by the signal processing device 20E. Under the control of the control device 47, WJP is applied to the component member 2 as in the second embodiment.

In the water jet peening method of the present embodiment, portions different from the second embodiment will be described. The first energy calculation device 87 calculates the energy of each shock wave based on the shock wave detection signals of the AE sensors 16A and 16B input from the A / D converter 21. The calculation of the energy of the shock wave will be specifically described using a shock wave detection signal shown in FIG. The heights of the waveform 50a, which is the output of the AE sensor 16A, and the waveform 50b, which is the output of the AE sensor 16B, are proportional to the energy of the shock wave. Waveforms 50a and 50b are generated by detecting one shock wave. The first energy calculation device 87 calculates energy Ea ₁ based on the height of the waveform 50a, and calculates energy Ea ₂ based on the height of the waveform 50b.

The calculated energy Ea ₁ , Ea _2, etc. and the shock wave generation position obtained by the position calculation device 23 are input to the second energy calculation device 88. When the distance between the shock wave generation position and each of the AE sensors 16A and 16B is La ₁ and La ₂ , the energy E of the shock wave generated at the generation position is {(Ea ₁ / La ₁ ² ) + ( Ea ₂ / La ₂ ² )} / 2. Further, the second energy calculation device 88 calculates the total energy ΣE received by the component member 2 by each shock wave. When the distance between the shock wave generation position and the surface of the component member 2 is L, the total energy ΣE received by the component member 2 is calculated by the equation (9).

ΣE = Σ (E _i / L _i ² ) (9)
Here, i is the number of shock waves generated per unit time.

  The calculated ΣE is stored in the storage device 49 and input to the scanning distance conversion device 86. The energy ΣE received by the component member 2 per unit time calculated by the second energy calculation device 88 is referred to as first energy for convenience. The scanning distance conversion device 86 converts the input first energy into energy per unit scanning distance of the nozzle 6 (hereinafter referred to as second energy).

  Also in the present embodiment, as in the sixth embodiment, the display information selection command is input from the operation panel 29 to the display information creating device 25. The display information creation command is either (e) creation of display information using the first energy, or (f) creation of display information using the second energy.

  It is assumed that, for example, creation of display information (e) is selected by the display information creation command. The display information creation device 25 creates the display information of the energy received by the component 2 based on the first energy information taken from the storage device 49. This display information is displayed on the display device 26 and stored in the storage device 49.

  When creation of display information in (f) is selected, the display information creation device 25 creates display information based on the second energy.

  The monitoring index in the present embodiment is different when the creation of display information (e) is selected and when the creation of display information (f) is selected. When (e) is selected, the monitoring index is the first energy, and the operating condition change threshold value and the improvement effect determination threshold value are for the first energy, respectively. When (f) is selected, the monitoring index is the second energy, and the operating condition change threshold value and the improvement effect determination threshold value are respectively for the second energy.

  Since (e) is selected, each determination of steps S18, S21 and S22 of this embodiment is performed using the first energy taken from the storage device 49. When (f) is selected, each determination of steps S18, S21 and S22 of this embodiment is performed using the second energy taken from the storage device 49.

  In the present embodiment, each effect produced in the second embodiment can be obtained. When the energy received by the structural member 2 per unit scanning distance is used, the effect of improving the residual stress in the WJP work object is confirmed with higher accuracy than when the energy received by the structural member 2 per unit time is used. can do.

  In the WJP apparatus 1C, the signal processing apparatus 20A can be changed to the signal processing apparatus 20E used in this embodiment. The water jet peening method of the fourth embodiment may be executed using the WJP apparatus 1C in which the signal processing apparatus 20A is replaced with the signal processing apparatus 20E. In this case, the effect produced in the fourth embodiment can be obtained.

  When the effects of Example 2 and Examples 5 to 8 are compared, the following can be said. The accuracy with which the improvement effect of the residual stress in the WJP construction object can be confirmed is the peak position of the shock wave frequency (for example, Example 2), the average value of the shock wave frequency (for example, Example 5), the effective shock wave frequency ( For example, in the order of Example 6), shock wave generation frequency corrected based on the distance (for example, Example 7) and energy received by the structural member 2 (for example, Example 8), the latter increases as the latter. The processing time in the signal processing apparatus is the energy received by the component 2 (for example, Example 8), the shock wave generation frequency corrected based on the distance (for example, Example 7), and the effective shock wave generation frequency (for example, Example 6). ), The average value of the shock wave generation frequency (for example, Example 5) and the peak position of the shock wave generation frequency (for example, Example 2), in order, the shorter the latter.

  Examples 1 to 8 described above can be applied to the improvement of the residual stress in the components of the pressurized water nuclear plant. Further, Examples 1, 2, and 5 to 8 described above are applied to the improvement of the stress of a steel rod immersed in seawater of a ship that is difficult to pull up from the sea to the land, and the dropping of a light spot attached to the steel plate. can do. 1, 2, and 5-8 may be applied to surface modification of automobile parts.

  The present invention can be applied to the improvement of the residual stress of the constituent members.

  1, 1A, 1B, 1C, 1D, 1E, 1F, 1G ... Water jet peening device, 4 ... Water tank, 5 ... High pressure pump, 6 ... Nozzle, 9 ... High pressure hose, 10, 10A ... Nozzle scanning device, 12, 14 , 19, 58A, 58B ... moving device, 13 ... first arm, 15 ... second arm, 16A, 16B, 16C ... AE sensor, 20,20A, 20B, 20C, 20D, 20E ... signal processing device, 22 ... time difference Calculation device, 23 ... Position calculation device, 24, 24A, 24B ... Shock wave counting device, 25 ... Display information creation device, 27 ... Nozzle scanning control device, 28 ... Pump control device, 35 ... Bubble, 36 ... Shock wave, 47 ... Control Device: 48 ... Peak position calculation device, 60 ... Arm, 62 ... Post member, 63 ... Elevator, 65 ... Turntable, 76 ... Reactor pressure vessel, 77 ... Core shura De, 85 ... mean value calculating apparatus, 86 ... scanning distance converter, 87 ... first energy calculating unit, 88 ... second energy calculating unit.

Claims (18)

  Water that is supplied from a pump is jetted from the nozzle into the water in which the nozzle is present, the nozzle that is jetting the water is scanned along the water jet peening object to be present in the water, and the nozzle A shock wave generated by collapsing bubbles contained in the water jetted into the water is applied to the water jet peening object, and the shock wave is detected by a plurality of shock wave detection devices arranged in the water, Based on the difference in detection time of the shock wave between one shock wave detection device and another shock wave detection device, the shock wave generation position is obtained, and based on the generation position, the surface of the water jet peening object The frequency of occurrence of the shock wave is obtained for each of a plurality of sections set in a direction away from the water jet pini. Grayed way.   The water jet peening method according to claim 1, wherein a monitoring index value is obtained based on the occurrence frequency of the shock wave for each of the plurality of sections.   The water jet peening method according to claim 2, wherein the monitoring index value is one of a value per unit time and a value per unit scanning distance of the nozzle.   When the value of the monitoring index is equal to or less than the first set value, the nozzle is scanned in a state where the scanning speed of the nozzle is reduced, and the value of the monitoring index of the water jet peening object is at least The water jet peening method according to claim 2 or 3, wherein the shock wave is applied to a portion that is equal to or less than a first set value.   When the value of the monitoring index is equal to or less than a second setting value that is greater than the first setting value and the value of the monitoring index is equal to or more than the first setting value, the nozzle is moved in a state where the scanning speed of the nozzle is reduced. The water jet peening method according to claim 2 or 3, wherein scanning is performed.   When the value of the monitoring index is equal to or less than a first set value, the nozzle is scanned in a state where either the pressure or the flow rate of the water discharged from the pump and supplied to the nozzle is increased, 4. The water jet peening method according to claim 2, wherein the shock wave is applied to a portion of the water jet peening object to which the value of the monitoring index is at least the first set value or less.   The water that is discharged from the pump and supplied to the nozzle when the value of the monitoring index is equal to or less than a second setting value that is greater than the first setting value and the value of the monitoring index is equal to or greater than the first setting value. The water jet peening method according to claim 2 or 3, wherein the nozzle is scanned in a state in which either the pressure or the flow rate is increased.   The monitoring index is a position where the occurrence frequency of the shock wave is maximized, the average value of the occurrence frequency of the shock wave, the occurrence frequency of the shock wave that contributes to the improvement of the residual stress existing in the water jet peening object, and the water jet peening 8. The corrected occurrence frequency obtained by correcting the occurrence frequency of the shock wave in consideration of the distance between the surface of the construction object and the generation position of the shock wave. 9. The water jet peening method described in 1.   The water jet peening method according to claim 1, wherein display information including information on occurrence frequency of shock waves for each of the plurality of sections is created, and the display information is displayed on a display device.   Water that is supplied from a pump is jetted from the nozzle into the water in which the nozzle is present, the nozzle that is jetting the water is scanned along the water jet peening object to be present in the water, and the nozzle A plurality of shock waves generated by collapsing bubbles contained in the water jetted into the water from the water jet peening object, and the plurality of shock waves detecting devices arranged in the water Based on the difference in detection time of the shock wave between one shock wave detection device and the other shock wave detection device, the occurrence position of each shock wave is obtained and detected by the plurality of shock wave detection devices The energy of each of the plurality of shock waves is obtained based on the detection signal of the shock wave, and the energy of the plurality of shock waves and the plurality of shock waves Based on the occurrence position of 撃波, water jet peening wherein said water jet peening object and obtains the energy received by the plurality of shock waves.   A nozzle for injecting water, a pump for supplying water to the nozzle, a nozzle scanning device to which the nozzle is attached to scan the nozzle, and a plurality of shock wave detection devices attached to the nozzle scanning device, Based on the difference in the detection time of the shock wave between the shock wave detection device and the other shock wave detection device, the generation position of the shock wave is obtained, and based on the generation position of the shock wave, the surface is separated from the surface of the water jet peening object. A water jet peening apparatus, comprising: a signal processing apparatus that obtains the frequency of occurrence of the shock wave for each of a plurality of sections set in a direction.   The water jet peening apparatus according to claim 11, further comprising: a display information generation apparatus that generates display information including information on the occurrence frequency of the shock wave for each of the plurality of sections; and a display apparatus that displays the display information.   The water jet peening device according to claim 11, further comprising the signal processing device that obtains a value of a monitoring index based on the occurrence frequency of the shock wave for each of the plurality of sections.   When the monitoring index value is less than or equal to a first set value, the nozzle scanning device is controlled to reduce the scanning speed of the nozzle, and when the scanning speed is reduced, the nozzle scanning device is controlled. The water jet peening apparatus according to claim 13, further comprising a control device that scans the nozzle at a location where the monitoring index value of the water jet peening object is at least a first set value or less.   When the monitoring index value is less than or equal to the second setting value, which is greater than the first setting value, and the monitoring index value is greater than or equal to the first setting value, the nozzle scanning device is controlled to reduce the nozzle scanning speed. The water jet peening apparatus according to claim 13, further comprising a control device that scans the nozzle in a state in which the nozzle is moved.   When the value of the monitoring index is equal to or lower than a first set value, the pressure of the water that is discharged from the pump and supplied to the nozzle by controlling the pump is increased. And when the flow rate is increased, the nozzle scanning device is controlled so that the nozzle of the water jet peening object is at a position where the value of the monitoring index is at least the first set value or less. The water jet peening device according to claim 13, further comprising a control device that scans the water.   When the value of the monitoring index is less than or equal to a second setting value greater than the first setting value and the value of the monitoring index is greater than or equal to the first setting value, the pump is controlled and discharged from the pump to the nozzle. 14. The apparatus includes a control device that increases either the pressure or the flow rate of the supplied water and controls the nozzle scanning device to scan the nozzle when either the pressure or the flow rate is increased. The water jet peening apparatus described in 1.   A nozzle for injecting water, a pump for supplying water to the nozzle, a nozzle scanning device to which the nozzle is attached to scan the nozzle, and a plurality of shock wave detection devices attached to the nozzle scanning device, A shock wave generation position is obtained based on a difference in shock wave detection time between the shock wave detection device and the other shock wave detection devices, and the shock wave detection signals detected by the plurality of shock wave detection devices are used to determine the shock wave detection position. A signal processing device that obtains energy of each of the plurality of shock waves and obtains energy received by the plurality of shock waves by the water jet peening object based on the energy of the plurality of shock waves and the generation positions of the plurality of shock waves. A water jet peening apparatus characterized by that.

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