JP4267539B2 - Tip structure of ultrasonic peening equipment - Google Patents

Description

  The present invention relates to an ultrasonic peening apparatus for impacting a surface of a metal material with a pin that vibrates with ultrasonic waves and improving the structure and shape of the surface layer of the metal material, specifically, ultrasonic peening. The present invention relates to a tip structure of a processing apparatus.

Fatigue in steel structures, especially steel bridges, several decades after construction, and in ships several years after entry into service, such as welds of steel members of structures and notches formed in steel members The occurrence of cracks due to this is a problem.
Further, in construction machines and the like, the occurrence of fatigue cracks in booms that are exposed to shocking repeated loads during use is a problem. In automobiles, fatigue cracks may be a problem in chassis, drive shafts, and the like.
In this way, when constructing structures and equipment using steel members, the design thickness of the member, welding form, etc. are designed in consideration of degradation of material performance due to fatigue and degradation of welded portion performance, etc. is doing.
Recently, it has been known that by applying ultrasonic peening to the surface of the material, plastic deformation is applied to the surface of the material, the crystal structure of the surface is improved, or the fatigue resistance can be improved by releasing the residual stress. For example, Patent Document 1 proposes a method for setting processing conditions when modifying the surface layer of a metal material.
In addition, ultrasonic peening treatment is applied to welds and notches to improve the structure and the shape of the notches to have a curved shape to reduce stress concentration and fatigue resistance of these parts. Research has been conducted on improving sex.
As such an ultrasonic peening apparatus, for example, Patent Document 2 discloses a transducer that generates ultrasonic waves, a wave guide that guides ultrasonic waves to the tip, and a hammer that is provided at the tip and vibrates by ultrasonic waves. An ultrasonic peening apparatus having a pin for use has been proposed.
JP 2004-169099 A US Pat. No. 6,467,321

Since this ultrasonic peening apparatus is relatively small, it can be processed manually, and has an advantage that only a required part can be processed.
FIG. 12 is a schematic cross-sectional view showing an outline of a conventional ultrasonic peening apparatus, and shows a state in which a peening process is performed at a narrow welded portion. The ultrasonic peening apparatus 1 includes a wave guide 5 including a transducer 2, a horn 3, and a waveguide 4, a striking pin 7, a holder 6 that holds the hitting pin, and a support 12 that supports the holder on the wave guide. Basically composed.
FIG. 13 is a perspective view showing a portion of the ultrasonic peening processing apparatus of FIG. 12, where (a) shows a tip structure, (b) shows a waveguide, and (c) shows a striking pin. However, as shown in FIGS. 12 and 13 (a), since the shaft of the hitting pin is attached in parallel to the direction of vibration propagation of the wave guide, the hitting pin is sufficient for the portion that requires peening. There is a point that should be improved from the viewpoint of giving a good peening effect and working efficiently.
For example, in a welded portion of a steel structure, there is a tensile residual stress corresponding to the yield stress of the material, and the weld toe is a kind of material in which the material surface and the weld metal form an acute angle. This part becomes a stress concentration part because a notch part (notch) is formed, and the fatigue strength is lowered, and a crack is likely to occur.
In order to improve fatigue strength, it is required to perform ultrasonic peening on such places to improve the structure in the vicinity of the weld and reduce the notch shape. Therefore, it is necessary to perform an ultrasonic peening process in a narrow place.
Specifically, the shaft of the striking pin attached to the tip of the ultrasonic peening apparatus is tilted by about 30 to 60 ° with respect to the material surface of the weld, and is swung (weaved) along the weld toe. It is efficient to proceed with the process.
However, as described above, the hitting pin of the conventional ultrasonic peening apparatus is attached so that the axial direction thereof is parallel to the vibration propagation direction of the wave guide (the direction of the wave guide axis or the direction of the main body axis). Therefore, in order to ensure an angle of 30 to 60 ° with respect to the weld toe, it is necessary to incline the processing apparatus main body including the wave guide by 30 to 60 °. However, as described above, it is difficult to ensure such an angle when processing is performed in a narrow place such as a welded portion.
As described above, there is a limitation in giving a sufficient peening effect to a required portion.

Further, as described above, it is preferable that the weld toe is subjected to ultrasonic peening treatment so that the shape of the weld toe has a certain curvature R (for example, R = 3 to 8 mm). However, when such a shape is used, a striking pin with a different diameter (for example, a striking pin diameter of 3 mm, 5 mm, etc.) is used rather than processing with a single striking pin having a curvature at the tip. It has been empirically found that it is efficient to use striking pins with different curvatures R and process them step by step.
However, the hitting pin of the conventional peening processing apparatus has only one type of hitting pin, and therefore, the tip of the peening processing apparatus, that is, the hitting pin, the holder, and the waveguide are exchanged. The striking pin with the required diameter can be used. This replacement takes time, and due to the processing site of the structure, this replacement operation usually has to be performed on a high place or a scaffold, and extremely high attention is required.
As described above, the conventional ultrasonic peening apparatus has a problem in the part to be processed and the work efficiency at the time of the process, and further improvement is required.
In view of the above situation, the present invention provides an ultrasonic peening apparatus that can be used in a wide range of sites and has excellent work efficiency, and in particular, an ultrasonic peening apparatus that has an improved tip structure. It is to provide.

The present invention has been made to solve the above-described problems, and the gist thereof is as follows.
(1) a transducer that generates ultrasonic waves;
Attached to a front of said transducer, and waveguide for guiding an ultrasonic wave to the front,
The tip structure of an ultrasonic peening apparatus having one or more striking pins attached to the tip of the wave guide and vibrated by the ultrasonic wave,
At least one of the striking pin has a tilt oblique angle with respect to the vibration propagation direction of the axial pre-Symbol waveguide,
The wave guide includes a horn attached in front of the transducer and a waveguide that contacts the striking pin,
The surface in contact with the striking pin in front of the waveguide has an inclined angle perpendicular to the axial direction of the striking pin,
The tip structure of the ultrasonic peening apparatus, wherein the bottom surface of the hitting pin is disposed in contact with the inclined surface in parallel .

(2) The tip part structure of the ultrasonic peening apparatus according to (1), wherein the plurality of hitting pins are all arranged with the same inclination angle.

(3) The tip structure of the ultrasonic peening apparatus according to (1), wherein the plurality of hitting pins are arranged with different inclination angles.

(4) The tip end structure of the ultrasonic peening apparatus according to any one of (1) to (3), wherein the plurality of hitting pins have different outer diameters.

(5) The tip end structure of the ultrasonic peening apparatus according to any one of (1) to (4), wherein the inclination angle of the hitting pin is 20 to 45 °.

  In the ultrasonic peening apparatus according to the present invention, in the structure of the tip portion, the shaft of the hitting pin is disposed with an inclination angle with respect to the vibration propagation direction of the wave guide. That is, the axis of the striking pin can be positioned at an angle of 30 to 60 ° with respect to the processing surface without greatly tilting the main body axis. Therefore, even in a narrow processing place, it is possible to perform effective processing with good workability on a welded portion, a cutout portion, or a sheared cross-sectional portion of a metal material.

  Preferably, in the tip structure, the plurality of striking pins are all arranged with the same inclination angle, so that processing can be efficiently performed even in a narrow processing place.

  Preferably, in the tip structure, a plurality of striking pins are arranged with different inclination angles, so that different angles can be obtained without replacing the tip structure with striking pins having different angles. Therefore, the processing work can be performed on the processing points in the area, and the work efficiency is improved.

  Preferably, in the tip structure, the plurality of striking pins have different outer diameters, so that a striking pin having an appropriate diameter can be selected according to the situation of the processing location without changing the tip structure. The peening process can be continued and the work efficiency is improved.

  Preferably, in the tip structure, by setting the angle of inclination of the striking pin to 20 to 45 °, an appropriate processing angle is taken with respect to the material surface of the processing location without significantly inclining the apparatus main body. Therefore, the degree of freedom in processing application and workability are improved.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic cross-sectional view showing an outline of an ultrasonic peening apparatus according to an embodiment of the present invention. The ultrasonic peening processing apparatus 1 is basically composed of a transducer 2, a horn 3, a waveguide 4, a striking pin 7, and a holder 6 that holds this.
In FIG. 1, description will be made assuming that the waveguide side is the front or front surface, the transducer side is the rear or rear surface, the direction perpendicular to the paper surface is left and right, and the up and down direction in the figure is up and down.
The longitudinal axes of the transducer 3, the horn 4, the waveguide 4, and the holder 6 are arranged so as to be coaxial C in this order toward the front.
The horn 3 and the waveguide 4 are also referred to as a wave guide 5. Further, the coaxial central axis C is a vibration propagation direction as described later, and is also referred to as a main body axis or a wave guide axis.
The tip portion structure of the present invention means a structure including a wave guide, a holder, and a striking pin, as will be described in detail.

The transducer 2 is composed of a magnetostrictive body 8 such as a permendur and a coil 9 wound around the magnetostrictive body 8, and generates vibration in the axial direction by electric energy from the power source 10. The horn 3 attached to the front of the transducer 2 has a front cross-sectional area that is smaller than a rear cross-sectional area, and amplifies vibration from the transducer.
A flange 11 is provided on a neutral shaft (node) in the axial direction of the horn 3, and the horn 3 is connected and fixed by a ring 20 with a case 20 and a support 12 described later through this flange.

  The waveguide body 4 has a cylindrical base portion and a flat front end portion formed by cutting both side surfaces of the cylinder from the base portion toward the front end, and a screw 13 provided on the base portion is connected to the horn 3. It is screwed and connected to the tip. An inclined surface 16 having an inclination angle with respect to the direction of the main body axis is formed at the distal end portion of the waveguide 4, and this inclined surface 16 has a relationship that is substantially perpendicular to the axial direction of a hitting pin 7 to be described later. And is in contact with the bottom surface of the striking pin 7 substantially in parallel.

  The support 12 is a cylindrical body having a flange at the rear end and having the front opened. As described above, the rear end flange is connected and fixed to the flange 11 of the horn 3 together with the case described later by the ring screw 14. A holder 6 which will be described later is inserted into the distal end portion of the support 12 and fixed and supported by a tightening ring 15 provided on the outer periphery of the support.

The holder 6 is a cylindrical member that includes a support portion 6a at the front and is open at the rear, and the support portion 6a of the holder is provided with a through-hole 18 that supports the striking pin.
The through hole 18 is provided so that its axis is in the same direction as the direction of the axis P of the striking pin. That is, the axis of the through hole 18 is provided so as to have an inclination angle with respect to the direction of the main body axis C, whereby the axis of the striking pin has an inclination angle with respect to the main body axis.
In terms of the relationship with the waveguide 4, the axis of the through hole 18, that is, the axis P of the hitting pin, has an angle substantially perpendicular to the inclined surface 16 on the front surface of the waveguide. That is, by making the relationship between the inclination angle formed by the main body axis and the inclined surface of the waveguide and the inclination angle formed by the main body axis and the axis of the striking pin, vibration energy efficiently propagates to the striking pin. preferable.
As described above, the holder 6 is inserted inside the support 12 and supported and fixed by the tightening ring 15 provided around the support 12. Thereby, the hitting pin 7 of the holder 6 is arranged in a state where its axis is perpendicular and close to the inclined surface 16 in front of the waveguide, that is, with an inclination angle with respect to the axial direction of the main body. It becomes a state.

  The striking pin 7 is usually composed of a material having excellent characteristics such as wear resistance, hardness, toughness, etc., for example, a rod-shaped member such as cemented carbide, and the rear end has a locking portion 19 formed flat. ing. The shape of the tip is not particularly defined, but is usually a downward convex shape with a curvature. Depending on the requirements of the shape of the processing location, a concave tip shape may be used. Further, the cross-sectional shape perpendicular to the axis of the striking pin is not limited to a circle and may be an ellipse.

  The cylindrical case 20 accommodates the horn 3, the lance reducer 2, and the like, the rear end thereof is sealed, and a handle 21 is attached to the outer surface thereof. The case can be filled with a coolant in order to cool the transducer or the like (for example, cooling water is circulated in and out of the case 20).

  Due to the electrical energy from the power source, the axial vibration generated by the transducer propagates to the horn, is amplified, propagates to the waveguide in front of the vibration propagation direction (the direction of the main body axis C), and The inclined surface is vibrated. This vibration is transmitted to the striking pin arranged close to the inclined surface, and the striking pin vibrates ultrasonically. As a result, the ultrasonic peening target object on the front surface, for example, a weld or notch of a metal structure is hit, the metal surface structure is modified, and the residual stress of the weld is reduced or released. The effects such as can be given.

As described above, the structure of the tip portion of the ultrasonic peening apparatus according to the present invention is such that the axial direction of the hitting pin has an inclination angle with respect to the vibration propagation direction. Thus, it is possible to efficiently perform the ultrasonic peening process in a narrow place where it is difficult to change the angle of the processing apparatus main body in order to obtain an appropriate angle.
Hereinafter, the tip structure of the present invention will be described more specifically with reference to the schematic views showing the tip structure of the ultrasonic peening apparatus of the present invention shown in FIGS.

2A and 2B are schematic views of another embodiment of the tip structure of the ultrasonic peening apparatus according to the present invention, in which FIG. 2A is a side sectional view and FIG. 2B is a perspective view showing the waveguide of FIG. It is.
In the embodiment of FIG. 2, the plurality of striking pins 7 is an example in which the axis P is arranged in the holder 6 with an inclination angle α ₁ downward with respect to the direction of the main body axis C. Although the downward direction is used, this is because, as described with reference to FIG. 1, this relationship is a vertical relationship in FIG. 1, and in FIG. 2, this corresponds to the downward direction.

Further, as shown in FIG. 2 (b), the inclined surface 16 is formed on the front surface of the waveguide 4 in the downward direction with respect to the direction of the main body axis in the same manner as the axial direction of the impact pin with respect to the direction of the main body axis C. It is formed to have a tilt angle beta _1. As described above, it is desirable that α ₁ and β ₁ have a reciprocal relationship, and the axis of the inclined surface 16 of the waveguide body and the striking pin disposed on the holder having the inclined angle are substantially perpendicular to each other. Built in.
Thereby, vibration energy is efficiently transmitted to the striking pin 7 having an inclination angle with respect to the main body axis C, and an ultrasonic peening process can be performed on a narrow portion.
In this embodiment, the shaft of the hitting pin is arranged with a downward inclination angle, but it goes without saying that it can be turned upward. Needless to say, the number of hitting pins is not limited to a plurality, and only one hitting pin may be provided.

3A and 3B are schematic views of another embodiment of the tip structure of the ultrasonic peening apparatus according to the present invention, in which FIG. 3A is a side sectional view and FIG. 3B is a perspective view showing the waveguide of FIG. It is.
In the embodiment of FIG. 2, the example in which the plurality of hitting pins 7 are arranged in the holder 6 with the axial direction having an inclination angle in the vertical direction with respect to the direction of the main body axis C is shown in FIG. 3. in embodiments, an example in which a plurality of blow pins 7 whose axes are arranged in the holder 6 has an inclination angle alpha ₂ in the right direction with respect to the direction of the body axis.
Although the rightward direction is used, this is because, as described in FIG. 1, this relationship is a left-right relationship in FIG. 1, and in FIG.

Further, as shown in FIG. 3B, the inclined surface 16 of the waveguide 4 is inclined in the right direction with respect to the direction of the main body axis in the same manner as the axial direction of the hitting pin with respect to the direction of the main body axis C. It is formed to have a beta _2. As described above, it is desirable that α ₂ and β ₂ have a reciprocal relationship, and the axis of the inclined surface 16 of the waveguide body and the striking pin disposed on the holder having the inclined angle substantially correspond to the axis. Built in.
Thereby, vibration energy is efficiently transmitted to the striking pin 7 having an inclination angle with respect to the main body axis, and an ultrasonic peening process can be performed on a narrow portion. In this example, the striking pin axis is arranged with a rightward inclination angle, but it goes without saying that it can be leftward.
3 shows an example in which a plurality of hitting pins are provided, it is needless to say that only one hitting pin may be provided.

  In the embodiment of FIGS. 2 and 3, the example in which the axes P of the plurality of hitting pins 7 are all arranged with the same inclination angle, for example, in the vertical or horizontal direction with respect to the direction of the main body axis C, In the following embodiments, a plurality of striking pins are arranged at different inclination angles so as to be able to cope with a wider range of situation fluctuations in the processing location.

4A and 4B are schematic views of another embodiment of the tip structure of the ultrasonic peening apparatus according to the present invention, in which FIG. 4A is a side sectional view and FIG. 4B is a perspective view showing the waveguide of FIG. It is.
In the embodiment of FIG. 4, among the plurality of hit pins, the shaft of one or more hit pins 7 has an inclination angle α ₃ downward with respect to the direction of the main body axis C, and the other hit pins 7 ′ In this example, the axis P is arranged in the holder 6 without having an inclination angle with respect to the main body axis C. Although the downward direction is used, this is because, as described with reference to FIG. 1, this relationship is a vertical relationship in FIG. 1, and in FIG. 4, this corresponds to the downward direction.

As shown in FIG. 4B, the front surface of the waveguide 4 has an inclined surface 16 formed so as to have a downward inclination angle β ₃ with respect to the direction of the main body axis, and the main body axis. Two surfaces of the vertical surface 17 formed perpendicular to the direction are formed. As described above, α ₃ and β ₃ are preferably in a relationship of a reciprocal angle, and the inclined surface 16 and the vertical surface 17 of the waveguide are formed by the striking pin 7 and the inclined surface arranged with an inclination angle. Needless to say, they are incorporated so as to correspond substantially perpendicularly to the axes P and P ′ of the striking pin 7 ′ arranged without an angle.
Accordingly, vibration energy is efficiently transmitted to the striking pin 7 having an inclination angle with respect to the main body axis and the striking pin 7 'having no inclination angle. And since it has the hit | damage pin 7 'of the impact pin 7' which has an inclination angle with respect to a main body axis | shaft, and the impact pin 7 'which does not have an inclination angle, it is an ultrasonic peening with respect to a narrow location. As a matter of course, the ultrasonic peening process can be continuously performed on an object in a direction perpendicular to the main body axis by simply changing the working posture without replacing the striking pin. .

In this example, a part of the plurality of striking pins is arranged such that the shafts of some striking pins have a downward inclination angle, but conversely, they can be arranged with an upward inclination angle. Further, in this example, the striking pin having an inclination angle with respect to the main body axis and the striking pin having no inclination angle are arranged, but the striking pin having the upward inclination angle and the impacting angle having the downward inclination angle are arranged. Needless to say, the pins may be arranged.
The number of striking pins having an inclination angle and striking pins having no inclination angle can be arbitrarily selected.

FIG. 5 is a schematic diagram of another embodiment of the tip structure of the ultrasonic peening apparatus according to the present invention, where (a) is a side sectional view and (b) is a perspective view showing the waveguide of (a). It is.
In the embodiment of FIG. 5, among the plurality of hit pins, the axial direction P of one or more hit pins 7 has an inclination angle α ₄ in the right direction with respect to the direction of the main body axis C, and the other hit pins 7. 'Is an example in which the direction of the axis P' is arranged on the holder 6 without having an inclination angle. Although the right direction is used, this is because, as described with reference to FIG. 1, this relationship is a left-right relationship in FIG. 1, and in FIG.

Further, as shown in FIG. 5B, the front surface of the waveguide 4 has an inclined surface 16 formed so as to have an inclination angle β ₄ in the right direction with respect to the direction of the main body axis C, and the main body axis. Two surfaces of the vertical surface 17 formed perpendicularly to the direction are formed. As described above, it is desirable that α ₄ and β ₄ have a complementary angle relationship, and the inclined surface 16 and the vertical surface 17 of the waveguide 4 are provided with the hitting pin 7 and the inclined angle arranged with an inclined angle. Needless to say, they are incorporated so as to correspond substantially perpendicularly to the axes of the striking pins 7 ′ arranged without having the axes P and P ′.
Accordingly, vibration energy is efficiently transmitted to the striking pin 7 having an inclination angle with respect to the main body axis and the striking pin 7 'having no inclination angle. And since it has the hit | damage pin 7 'of the impact pin 7' which has an inclination angle with respect to a main body axis | shaft, and the impact pin 7 'which does not have an inclination angle, it is an ultrasonic peening with respect to a narrow location. As a matter of course, the ultrasonic peening process can be continuously performed on an object in a direction perpendicular to the main body axis by simply changing the working posture without replacing the striking pin. .

In this example, among the plurality of striking pins, some striking pin shafts are arranged so as to have an inclination angle in the lower right direction, but conversely, they can be arranged with an inclination angle in the left direction. . Further, in this example, the striking pin having an inclination angle with respect to the main body axis and the striking pin having no inclination angle are arranged. However, as shown in FIG. Needless to say, a pin and a striking pin having a leftward inclination angle may be arranged.
The number of striking pins having an inclination angle and striking pins having no inclination angle can be arbitrarily selected.

6A and 6B are schematic views of another embodiment of the tip structure of the ultrasonic peening apparatus of the present invention, where FIG. 6A is a side sectional view and FIG. 6B is a perspective view showing the waveguide of FIG. It is.
6 embodiment, among the plurality of blow pins, the direction of the axis P1 of one or more of the striking pin 7-1 has a inclination angle alpha ₅ in the right direction with respect to the direction of the body axis C, also have axes P2 of more than one of the striking pins 7-2 the inclination angle alpha ₆ in the left direction with respect to the direction of the body axis C, and the other blow pin 7 'is its axis P' is the direction of inclination This is an example in which the holder 6 is arranged without an angle. Note that the right direction and the left direction indicate that this relationship is a left-right relationship in FIG. 1 and corresponds to the left and right in FIG. 5 as described in FIG.

Further, as shown in FIG. 6 (b), the front face of the waveguide 4, an inclined surface 16-1 which is formed to have an inclination angle beta ₅ in the right direction with respect to the direction of the body axis C, the body an inclined surface 16-2 which is formed to have an inclination angle beta ₆ in the left direction with respect to the direction of the axis C, three aspects of a vertical plane 17 formed perpendicularly to the direction of the body axis C is formed ing. alpha ₅ and beta _5, and alpha ₆ beta ₆ as described above, desirably in a relation of complementary angle, rightist slope 16-1 waveguide 4, left inclined plane 16-2 and the vertical plane 17, the holder The striking pin 7-1 is disposed with a rightward tilt angle, the striking pin 7-2 is disposed with a leftward tilt angle, and the striking pin 7 is disposed without a tilt angle. Needless to say, they are incorporated so as to correspond substantially perpendicularly to the 'axis P1, P2, P'.
Thus, the striking pin 7-1 having a rightward tilt angle with respect to the main body axis, the striking pin 7-2 having a leftward tilt angle with respect to the main body axis, and a tilt angle are provided. Vibration energy is efficiently transmitted to the non-striking pin 7 '. And since it has three-way striking pins, striking pins 7-1 and 7-2 having a right and left tilt angle with respect to the main body axis and a striking pin 7 'having no tilt angle, The scope of application can be further expanded from the embodiment shown in FIG. 5, and the ultrasonic peening process can be applied to a narrow portion. The ultrasonic peening process can be continuously performed only by changing the working posture without replacing the striking pin.

As described above, the axial direction of the striking pin in the tip structure of the ultrasonic peening processing apparatus of the present invention has, for example, an α _{1 to} α ₆ inclination angle with respect to the direction of the main body axis. This should be set in consideration of the situation. Usually, the inclination angle is preferably 20 to 45 °. By having this inclination angle, it is possible to perform peening processing on a required part without significantly tilting the ultrasonic peening processing apparatus body when performing ultrasonic peening processing on a normal narrow portion. Become.

  By the way, in the tip part structure of the conventional ultrasonic peening processing apparatus, the diameter of the striking pin is usually around 3 to 5 mm, and when a plurality of striking pins are arranged, from the viewpoint of increasing the processing area, It was mainly to arrange a plurality of pins having the same diameter within a range of diameters. However, in particular, in order to alleviate the stress concentration at locations where the angle of the weld toe or notch changes abruptly, apply ultrasonic peening to make the location with a gentle curvature. In this case, if the diameter of the hitting pin is one type, it is difficult to form a required ratio at the location, and the work efficiency must be reduced by replacing the hitting pin with a different diameter.

FIG. 7 is a side sectional view of another embodiment of the tip structure of the ultrasonic peening apparatus of the present invention. That is, in the embodiment of FIG. 7, a plurality of striking pins having different diameters, a small striking pin 7-3, a medium striking pin 7-4, and a large striking pin 7 at the tip of the ultrasonic peening apparatus. This is an example in which the above point is improved by arranging −5.
In this example, as shown in FIG. 3, a plurality of blow pins are disposed have the same inclination angle alpha ₂ in the right direction with respect to the body axis, each striker has diameter each different . In addition, what is necessary is just to select the diameter of a different striking pin in consideration of the shape of the process site | part of a process target object, and it is preferable to set it as a different diameter normally in the range of 3-5 mm. Moreover, even when the tip structure described in FIGS. 1 to 6 is provided with a plurality of hitting pins, it goes without saying that hitting pins having different diameters can be arranged.

FIGS. 8A to 8D are schematic cross-sectional views showing a situation in which an ultrasonic peening process is performed on a weld toe by a peening apparatus having a tip structure of the present invention.
As shown in FIG. 8 (a), the cross-sectional shape of the weld toe 23 of the welded portion 22 changes abruptly between the material surface and the tensile residual stress is concentrated, which tends to be a starting point for fatigue cracks. . In order to prevent this, an ultrasonic peening treatment is performed to obtain a cross-sectional shape having a curvature. First, as shown in FIG. 8B, a striking pin having a large diameter, for example, as shown in FIG. An ultrasonic peening process is applied to the periphery of the toe portion 23 by the striking pin 7-5, so that the peripheral portion has a gentle curvature. Next, as shown in FIG. 8 (c), the toe portion is subjected to ultrasonic peening with a small diameter striking pin, for example, a striking pin 7-3 as shown in FIG. Then, as shown in FIG. 8 (d), the cross-sectional shape having one curvature is formed at the toe portion and the periphery thereof in a continuous manner with the curvature of the toe portion and the periphery thereof. Note that this processing order is not limited to that shown in FIG. 8, and it is needless to say that (b) and (c) may be reversed, and may be further multi-staged.
Thus, according to the ultrasonic peening apparatus having the tip structure of the present invention, since the diameters of the plurality of striking pins are different, it is possible to select and use the striking pins necessary to form the desired curvature. Therefore, it is not necessary to replace the striking pin each time, the work can be performed continuously, and the work efficiency is extremely high.

  In the description of the tip structure of the ultrasonic peening apparatus according to the present invention, the hitting pins are shown in a line in the left-right direction or the up-down direction. FIG. 9 is a front view showing another example of the tip structure of the ultrasonic peening apparatus according to the present invention. As shown in FIG. Needless to say, it may be arranged.

Hereinafter, the present invention will be described more specifically with reference to examples.
[Example 1]

  FIG. 10 is a perspective view showing an embodiment showing a situation in which ultrasonic welding peening is performed on a welded portion of a structure by a peening treatment apparatus having a tip structure of the present invention, and an example of a steel girder 24 for an overhead crane. It is. As shown in FIG. 10, the upper and lower flanges 25u and 25l and the front and rear webs 26f and 26b connecting the upper and lower sides are basically constructed by welding (inner dimensions of the girder: height 2,200 mm × A width of 900 mm, a rib interval: 500 mm, an upper flange length of 30 m), and the wheel of the crane body travels on the upper flange in the direction of the girder axis (the direction of the arrow in the figure). Therefore, the rib 27 for preventing local deformation of the upper flange is welded to the lower surface of the upper flange 25u and the webs 26f, 26b. In addition, the distance in the beam axis direction is 500 mm from the structural design. Even in such a structure, fatigue cracks may occur in the welded portion 28 between the rib 27 and the lower surface of the upper flange 25u and the webs 26f and 26b due to long-term use. Conventionally, after a crack is generated, a detailed investigation is performed to confirm the size of the crack, and the repair is performed by grinding and re-welding the cracked part, and the work load is extremely large.

For this reason, the application of ultrasonic peening treatment, which has a great effect as a fatigue improvement measure, has been studied. However, since the distance between the steel spar 24 ribs 27 is 500 mm, the conventional ultrasonic peening treatment apparatus uses a welded portion 28 around the ribs. It turned out that it was difficult to hit the hitting pin along with. Therefore, the tip of the present invention provided with a holder provided with one striking pin having an inclination angle of 30 ° with respect to the main body axial direction of the ultrasonic peening processing apparatus as shown in FIG. 10 and a waveguide corresponding thereto. A partial structure was prepared, and this was attached to the tip of the ultrasonic peening apparatus 1 for processing.
As a result, ultrasonic peening can be applied to the welded portion, weld toe portion, and the like in narrow places that could not be processed by conventional devices, and fatigue measures can be taken over 30 m of steel girders. did it.
Conventionally, inspections and repairs were required every few years, but since this ultrasonic peening process could be performed, it is considered that inspections and repairs every several decades are sufficient.
[Example 2]

FIG. 11 is a perspective view showing another embodiment in which ultrasonic welding peening is performed on a welded portion of a structure by a peening apparatus having a tip structure according to the present invention, and is a jacket-type structure used for a pier on the coast. 29 examples. As shown in FIG. 11, the steel pipe is assembled by welding to a frame structure.
Since this structure receives an external load due to wave force, fatigue countermeasures for welds are a major issue. Conventionally, the structure type is designed to reduce the stress generated at the welds, and the thickness of the steel pipe is increased. Selected.
In the case of the structure of the embodiment shown in FIG. 11, the fatigue design stress is increased on the premise that the welded portion 32 is subjected to ultrasonic peening, and the vertical member 30 has an outer diameter of 800 mm and a wall thickness. Each of the 12 mm and diagonal members 31 was a steel pipe having an outer diameter of 600 mm and a thickness of 9 mm.
In the conventional structural design, on the premise that such ultrasonic peening treatment cannot be performed, the thickness of the steel pipe is designed to be large, the thickness of the vertical member 30 is 19 mm, and the thickness of the oblique member 31 is 12 mm. Become.
As can be seen from FIG. 11, the welded portion 32 of the vertical member 30 and the oblique member 31 has an angle formed by the shafts of both steel pipe members of about 30 °. And the welding part of the narrow part 33 used as the base end part cannot perform sufficient peening process with the conventional ultrasonic peening processing apparatus.

Therefore, one striking pin having an inclination angle of 30 ° with respect to the main body axis direction of the ultrasonic peening apparatus as shown in FIG. 11 and two parallel to the main body axis direction, that is, no inclination angle. A tip structure of the present invention having a holder having a total of three striking pins and a corresponding waveguide is prepared, and this is attached to the tip of the ultrasonic peening apparatus 1 for processing. It was.
In other words, depending on the situation of the treatment site, either a striking pin having an inclination angle or a striking pin having no inclination angle can be selected to perform the peening process.
In the form of this embodiment, by providing two types of hitting pins, those having an inclination angle and those not having such an inclination angle, the tip surface shape corresponding to the shape of the holder can be changed in addition to the middle replacement of the holder. It is not necessary to replace the waveguide that is provided, and the working efficiency can be further improved by 30% or more compared to the case of having only one kind of inclination angle.
It should be noted that since the space between the outer surfaces of both the steel pipe members is widened at a portion other than the narrow portion, peening is performed even in an ultrasonic peening apparatus having a striking pin that is parallel to the main body axial direction, that is, has no inclination angle. Processing can be performed.

It is a cross-sectional schematic diagram which shows the outline | summary of the ultrasonic peening processing apparatus of one Embodiment of this invention. It is a schematic diagram of other embodiment of the front-end | tip part structure of the ultrasonic peening processing apparatus of this invention, (a) is a sectional side view, (b) is a perspective view which shows the waveguide body of (a). It is a schematic diagram of other embodiment of the front-end | tip part structure of the ultrasonic peening processing apparatus of this invention, (a) is a sectional side view, (b) is a perspective view which shows the waveguide body of (a). It is a schematic diagram of other embodiment of the front-end | tip part structure of the ultrasonic peening processing apparatus of this invention, (a) is a sectional side view, (b) is a perspective view which shows the waveguide body of (a). It is a schematic diagram of other embodiment of the front-end | tip part structure of the ultrasonic peening processing apparatus of this invention, (a) is a sectional side view, (b) is a perspective view which shows the waveguide body of (a). It is a schematic diagram of other embodiment of the front-end | tip part structure of the ultrasonic peening processing apparatus of this invention, (a) is a sectional side view, (b) is a perspective view which shows the waveguide body of (a). It is a sectional side view of other embodiment of the front-end | tip part structure of the ultrasonic peening processing apparatus of this invention. (A)-(d) is a schematic diagram which shows the condition where the welding toe part is ultrasonically peened by the peening process apparatus provided with the front-end | tip structure of this invention. It is a front view which shows the other example of the front-end | tip part structure of the ultrasonic peening processing apparatus of this invention. It is a perspective view which shows one Example which shows the condition where the welding part of a structure is ultrasonically peened by the peening process apparatus provided with the front-end | tip structure of this invention. It is a perspective view which shows the other Example about the condition which carries out the ultrasonic peening process of the welding part of a structure with the peening process apparatus provided with the front-end | tip structure of this invention. It is a cross-sectional schematic diagram which shows the whole conventional ultrasonic peening processing apparatus together with the condition of performing ultrasonic peening processing in the narrow part of a structure. It is a perspective view which shows the part of the conventional ultrasonic peening processing apparatus of FIG. 12, (a) is a front-end | tip part structure, (b) is a waveguide body, (c) shows an impact pin.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ultrasonic peening processing apparatus 2 Transducer 3 Horn 4 Waveguide 5 Wave guide 6 Holder 6a Holder support part 7, 7 ', 7 ", 7-1 to 7-5 Impact pin 8 Magnetostrictive body 9 Coil 10 Power supply 11 Flange 12 Support 13 Screw 14 Ring screw 15 Tightening ring 16, 16-1, 16-2 Inclined surface 17 Vertical surface 18 Through hole 19 Locking portion 20 Case 21 Handle 22 Welding portion 23 Welding toe end 24 Steel girder 25u Top Flange 25l Lower flange 26f Front web 26b Rear web 27 Rib 28 Welded portion 29 Jacketed structure 30 Vertical member 31 Diagonal member 32 Welded portion 33 Narrow portion α, α _{1 to} α ₆ Inclination angle of striking pin β, β _{1 to} β ₆ Inclination angle of inclined surface C Body shaft (wave guide shaft)
P, P ′, P ″, P1, P2 Stroke pin axis T Object to be treated

Claims (5)

A transducer that generates ultrasound,
Attached to a front of said transducer, and waveguide for guiding an ultrasonic wave to the front,
The tip structure of an ultrasonic peening apparatus having one or more striking pins attached to the tip of the wave guide and vibrated by the ultrasonic wave,
At least one of the striking pin has a tilt oblique angle with respect to the vibration propagation direction of the axial pre-Symbol waveguide,
The wave guide includes a horn attached in front of the transducer and a waveguide that contacts the striking pin,
The surface in contact with the striking pin in front of the waveguide has an inclined angle perpendicular to the axial direction of the striking pin,
The tip structure of the ultrasonic peening apparatus, wherein the bottom surface of the hitting pin is disposed in contact with the inclined surface in parallel .   The tip structure of the ultrasonic peening apparatus according to claim 1, wherein the plurality of hitting pins are all arranged with the same inclination angle.   The tip structure of the ultrasonic peening apparatus according to claim 1, wherein the plurality of hitting pins are arranged with different inclination angles.   The tip portion structure of an ultrasonic peening apparatus according to any one of claims 1 to 3, wherein the plurality of striking pins have different outer diameters.   The tip portion structure of an ultrasonic peening apparatus according to any one of claims 1 to 4, wherein the inclination angle of the hitting pin is 20 to 45 °.

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