JP6472020B2 - Pass / fail judgment method and pass / fail judgment device for bar joint surface - Google Patents

Description

  The present invention relates to a quality determination method and quality determination device for a bar joint surface, and particularly relates to a method and apparatus for simply determining the quality of a bonded state of a bar end surface to which another member is bonded using ultrasonic waves. is there.

  For example, a method disclosed in Patent Document 1 has been proposed as a method for determining the quality of a bar joint surface. Here, an ultrasonic wave is transmitted from the direction perpendicular to the bar from the ultrasonic receiver, and the transmitted ultrasonic wave is reflected perpendicularly to the axial direction of the bar by the reflecting surface formed in the positioning part through which the bar is inserted. Then, the ultrasonic wave is vertically incident on the bonding surface, and the reflected ultrasonic wave that is reflected by the bonding surface and returns on the same path is received by the ultrasonic receiving oscillator, thereby determining the quality of the bonding surface. .

JP 2004-233144 A

  The above conventional determination method is useful when performing detailed pass / fail determinations for each region of the joint surface, but it requires time and effort to adjust the positioning portion and adjust the incident angle of the ultrasonic wave on the reflective surface. There has been a problem, and there has been a demand for a method that can easily perform pass / fail judgment of a bar joint surface.

  Accordingly, the present invention has been made in view of such a demand, and an object thereof is to provide a quality determination method and quality determination device for a bar joint surface that can easily perform quality determination of a bar joint surface. .

In order to achieve the above object, in the quality determination method for the bar joint surface according to the first aspect of the present invention, the bar (1) is compared with the bar (1) having the other member (2) joined to one end (12). The ultrasonic receiver / oscillator (4) is brought into contact with one part of the surface to output ultrasonic waves transmitted from the ultrasonic receiver / oscillator (4) in the axial direction of the bar (1), and the base of the other member The outer peripheral surface of the rod (1) on the other end (11) side while gripping the end by the chuck portion (3) of the rotating spindle and rotating the rod (1) around its axis (C). Joining the other member (2) to the other member (2) while applying a predetermined load in the axial direction to cause a bending stress on the joining surface (1a) of the other member (2) and the bar (1) The quality of the joint surface (1a) is determined from the intensity fluctuation of the reflected wave reflected from the surface (1a) and returning to the ultrasonic wave receiving oscillator (4). Here, as the ultrasonic wave transmitted in the axial direction of the bar, surface wave ultrasonic waves or oblique ultrasonic waves can be used.

In the first aspect of the present invention, when the intensity fluctuation of the reflected wave reflected from the joint surface is detected during one rotation of the bar, the intensity fluctuation of the reflected wave from the good joint surface is relatively small, The intensity fluctuation of the reflected wave from the defective joint surface becomes relatively large. Therefore, the quality of the joint surface can be easily and reliably determined from the magnitude of the intensity fluctuation of the reflected wave. When a load is applied to the other end of the bar, bending stress is applied to the joint surface, the joint surface opens and the defect width increases. In this way, the intensity fluctuation of the reflected wave from the good joint surface is almost the same as when no load is applied, while the intensity fluctuation of the reflected wave from the defective joint surface is further increased. Thereby, the quality of a joint surface can be determined still more reliably.

In the quality determination apparatus for the bar joint surface according to the second aspect of the present invention, the bar (1) having the other member (2) joined to one end (12) is placed at one place on the surface of the bar (1). The ultrasonic receiver / oscillator (4) that outputs ultrasonic waves that are contacted and transmitted in the axial direction of the rod (1), and the proximal end of the other member are gripped by the chuck portion (3) of the rotating spindle. Rotation drive means (3) for rotating the rod (1) around its axis (C), and an axial direction in one place on the outer peripheral surface on the other end (11) side of the rod (1) A load application mechanism that applies a predetermined load from the above to generate bending stress on the joint surface (1a) between the other member (2) and the bar (1), and the joint surface (1a) between the other member (2) And determining means for determining the quality of the joint surface (1a) based on the intensity fluctuation of the reflected wave reflected back to the ultrasonic receiving oscillator (4).

In the second invention , the same effect as that of the first invention can be obtained.

  The reference numerals in the parentheses indicate the correspondence with specific means described in the embodiments described later.

  As described above, according to the present invention, it is possible to easily and reliably determine whether or not the bar joint surface is good.

It is a side view of an engine valve to which the present invention is applied. It is a side view of an engine valve showing an ultrasonic transmission path. It is a graph which shows the intensity | strength change of an ultrasonic reflected wave with time. It is a graph which shows the intensity | strength change of the ultrasonic reflected wave from a favorable joint surface at the time of rotating an engine valve once. It is a graph which shows the intensity | strength change of the ultrasonic reflected wave from a bad joint surface at the time of rotating an engine valve once. It is a graph which shows the intensity | strength change of the ultrasonic reflected wave from a favorable joint surface at the time of rotating an engine valve once in the state which applied the load to the engine valve. It is a graph which shows the intensity | strength change of the ultrasonic reflected wave from a defective joint surface at the time of rotating an engine valve once in the state which applied the load to the engine valve.

  The embodiment described below is merely an example, and various design improvements made by those skilled in the art without departing from the gist of the present invention are also included in the scope of the present invention.

  FIG. 1 shows an engine valve E in which the quality of the joint surface is judged by the method of the present invention, and the tip 11 is formed in a trumpet shape. The engine valve E is, as another member made of heat-resistant steel having different components, joined to the distal half 1 of a circular cross-section made of heat-resistant steel as a rod and the base end (one end) 12 thereof by, for example, friction welding. And a proximal half portion 2 having a circular cross section of the same diameter.

  In applying the method of the present invention, the base end side half 2 of the engine valve E is gripped by the chuck portion 3 of the rotation main shaft of the base end 21, and the engine valve E is indicated by a thin arrow in FIG. Is rotated about its axis C. A load applying mechanism (not shown) is brought into contact with the outer peripheral surface near the tip (other end) 11 of the tip half 1 so that a load can be applied from the direction perpendicular to the axis as shown by a thick arrow in FIG. It has become. By applying a load, bending stress is generated in the joint surface 1a, the joint surface opens, the defect width increases, and as described later, the pass / fail judgment of the joint surface 1a is made more than when no load is applied. It can be done easily and reliably.

  A surface wave probe 4 as an ultrasonic receiving oscillator is brought into contact with the outer peripheral surface of the engine valve E through the machine oil applied to the outer peripheral surface of the half portion on the outer peripheral upper surface of the intermediate portion of the tip half 1 of the engine valve E. Yes. The surface wave probe 4 is supported by a support member (not shown) and is stationary with respect to the outer peripheral surface of the rotating engine valve E.

  When determining the quality of the joint surface 1a between the proximal half 1 and the distal half 1 as shown in FIG. 2, the distal half is removed from the piezoelectric vibrator 41 provided in the surface wave probe 4 as shown in FIG. Ultrasonic waves (for example, 5 MHz) are incident obliquely toward the outer peripheral surface of the unit 1. When the incident angle θ at this time is set so that the refraction angle in the material is slightly larger than the critical angle, the outer peripheral surface of the engine valve E is directed toward the joint surface 1a as indicated by the solid line arrow in the figure. Thus, a surface wave transmitted in the axial direction of the engine valve E is generated. The surface wave is reflected by the bonding surface 1a or the like (broken line in the figure) and returns to the piezoelectric vibrator 41. By detecting the intensity fluctuation of the reflected wave, it is possible to determine the quality of the joint surface 1a as described below.

  As shown in FIG. 3, the reflected wave is actually reflected wave Rx on the outer peripheral surface of the engine valve E, that is, the incident surface, or the base end surface 2a of the base end side half 2 in addition to the reflected wave Ra from the joint surface 1a. Therefore, only the reflected wave Ra from the joint surface 1a is detected by setting an appropriate detection window.

  FIG. 4 shows a change in reflected wave intensity from a good joint surface 1a when the engine valve E is rotated once, and FIG. 5 shows a change in reflected wave intensity from a bad joint surface 1a. The reflected wave intensity is obtained by adjusting the receiving sensitivity so that the reflected wave intensity is 60% when a white skin defect having a depth of 0.1 mm is artificially formed on the joint surface 1a. As is apparent from FIGS. 4 and 5, the reflected wave intensity from the good joint surface 1a has a small fluctuation during one rotation of the engine valve E, whereas the reflected wave intensity from the defective joint surface 1a is not the engine. Fluctuates greatly during one rotation of the valve E. Therefore, it is determined that the joint surface is defective when the fluctuation of the reflected wave intensity increases beyond a predetermined threshold.

  FIG. 6 shows a change in reflected wave intensity from the good joint surface 1a when the engine valve E is rotated once with a load of 100 N applied, and FIG. 7 shows a bad joint surface under the same conditions. The change of the reflected wave intensity from 1a is shown. As apparent from FIGS. 6 and 7, even when a load is applied to the good joint surface 1 a, the fluctuation of the reflected wave intensity during one rotation of the engine valve E is small, while the reflection from the defective joint surface is small. The wave intensity fluctuates greatly during one rotation of the engine valve E when a load is applied. Therefore, also in this case, it is determined that the joint surface 1a is defective when the fluctuation of the reflected wave intensity exceeds a predetermined threshold value. This determination can be performed more easily and reliably because the fluctuation of the reflected wave intensity at the defective bonding surface 1a is much larger than the fluctuation of the reflected wave intensity at the good bonding surface 1a. .

  In addition, in order to remove the influence of the fluctuation of the surface wave due to the burr on the surface of the engine valve E, the level difference of the joint, etc., the reflected wave intensity when the load is applied and the reflected wave intensity when the load is not applied You may make it determine the quality of the joint surface 1a from the magnitude | size of the fluctuation | variation of the said difference taking the difference. Further, instead of surface wave ultrasonic waves, oblique ultrasonic waves transmitted in the axial direction of the engine valve may be used. Furthermore, it is preferable to always detect the presence or absence of the reflected wave Rx from the base end surface 2a of the base end side half 2 to confirm that ultrasonic waves are reliably transmitted to the engine valve E. Further, the bar is not limited to a solid material, and may be a hollow material.

  DESCRIPTION OF SYMBOLS 1 ... End side half (bar), 1a ... Joining surface, 11 ... End (other end), 12 ... Base end (one end), 2 ... Base end side half (other members), 3 ... Chuck part, 4 … Surface wave probe (ultrasonic wave receiving oscillator), E… Engine valve.

Claims (3)

An ultrasonic wave receiving oscillator is brought into contact with a bar material with another member bonded to one end on one surface of the bar material, and ultrasonic waves transmitted from the ultrasonic wave receiving oscillator in the axial direction of the bar material are output. Then, the base end of the other member is gripped by the chuck portion of the rotating main shaft and the bar is rotated relative to the center of the bar, while the other end of the bar is axially perpendicular to one place. From the fluctuation of the intensity of the reflected wave that is reflected at the joint surface between the other member and applied to the joint surface between the other member and the bar member while applying a predetermined load from A method for determining the quality of a bar joint surface, wherein the quality of a surface is determined. The method for determining whether or not a bonded surface is good according to claim 1, wherein the ultrasonic wave transmitted in the axial direction of the bar is a surface wave ultrasonic wave or an oblique ultrasonic wave. An ultrasonic receiving oscillator that outputs ultrasonic waves that are transmitted to the bar in the axial direction by being brought into contact with one part of the surface of the bar with respect to the bar with the other member joined to one end, and the other Rotation driving means for gripping the base end of the member by the chuck portion of the rotation main shaft and relatively rotating the bar around its axis, and one axially outer peripheral surface of the bar from the axial direction A load application mechanism that generates a bending stress on the joint surface between the other member and the bar by applying a predetermined load, and an intensity fluctuation of the reflected wave that is reflected by the joint surface between the other member and returns to the ultrasonic receiving oscillator And a determination unit for determining whether or not the joint surface is good.

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