JP4168764B2 - Joint inspection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a joint inspection method and inspection device. More particularly, the present invention relates to an inspection method and an inspection apparatus for a joint that inspects a joint between a plurality of members using ultrasonic waves.
[0002]
[Prior art]
Conventionally, an inspection method using ultrasonic waves has been performed as an inspection method for a joint portion of a plurality of metals joined by brazing, diffusion joining, or the like.
[0003]
Such an inspection method mainly enters an ultrasonic wave into the joint surface of each member, measures the sound pressure of the ultrasonic wave reflected at the interface, and depends on the magnitude (echo height) of the measured ultrasonic sound pressure. This is carried out by examining the presence or absence of defects such as peeled portions at the joint.
[0004]
In recent years, such a joint inspection method has been achieved by forming a rotor (hot wheel) blade, which is conventionally made of steel and integrally formed with a shaft, in a turbocharger rotor of an automobile from a titanium aluminum alloy. The importance is increasing by realizing a revolutionary technology that reduces the weight of the rotor by connecting it to a steel shaft by brazing and significantly improves the rotational performance.
[0005]
On the other hand, in order to improve the inspection performance so that small defects can be detected in the ultrasonic inspection method, it is necessary to reduce the diameter of the ultrasonic beam. To that end, it is effective to use a point focus type ultrasonic probe. is there.
[0006]
However, as shown in FIG. 8, when the joint surface 103 between the shaft 101 and the blade central portion 102 is an inspection target, the ultrasonic wave 104 a is incident by the point focus type probe 104 from the direction perpendicular to the joint surface 103. When trying to inspect, as shown in FIG. 9, it is possible to inspect the intermediate portion of the joint surface 103, but it is difficult to inspect the peripheral portion with sufficient accuracy.
[0007]
In order to cope with this, as shown in FIG. 10, a tandem creeping wave probe 105 in which a transmission probe 105a and a reception probe 105b are arranged in tandem (see Japanese Patent Application Laid-Open No. 2002-5907). A method of inspecting the joint 103 by injecting ultrasonic waves obliquely from the side surface of the shaft 101 can be considered. However, as shown in FIG. 11, there is a problem that this method cannot inspect the shaft 106 having a shape in which an appropriate ultrasonic incident surface cannot be obtained, such as a step 106a in the vicinity of the joint 103.
[0008]
[Problems to be solved by the invention]
The present invention has been made in view of the problems of the prior art, and inspects a joint with high accuracy from the vertical direction even in an inspection object that is inherently difficult to probe from the vertical direction, such as a joint on the shaft end surface. It is an object of the present invention to provide an inspection method and an inspection apparatus for a joint that can be used.
[0009]
[Means for Solving the Problems]
The joint inspection apparatus of the present invention includes an ultrasonic sensor that makes an ultrasonic wave incident on a joint surface of a test material, a reflective surface that reflects ultrasonic waves from the ultrasonic sensor to the joint surface, and the reflective surface. An incident angle adjustment unit having a support mechanism that supports an angle of incidence from the ultrasonic sensor in a predetermined angle range so as to be adjustable, and a test material so that ultrasonic waves incident from the ultrasonic sensor scan in the circumferential direction. A rotating part, a positioning part for removing shaft runout so that the test material can be rotated at a predetermined position, a sensor control part for controlling the ultrasonic sensor, and determination of a joint part from the output of the ultrasonic sensor And a determination processing unit configured to switch the region to be inspected by adjusting the incident angle so that ultrasonic waves incident on the joint surface from the ultrasonic sensor scan concentrically. The determination processing unit Wherein the determining the quality of the joint by a threshold set for each of the areas.
[0013]
[Action]
Since the method for inspecting a joint portion of the present invention is configured as described above, the inspection accuracy of the joint portion is improved.
[0014]
In addition, since the joint inspection apparatus according to the present invention is configured as described above, even in an inspection object that is inherently difficult to probe from the vertical direction, such as a joint on the shaft end surface, it is possible to perform high-precision joining from the vertical direction. Parts can be inspected.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, although the present invention is explained based on an embodiment, referring to an accompanying drawing, the present invention is not limited only to this embodiment.
[0016]
FIG. 1 is a functional block diagram showing the configuration of a joint inspection apparatus according to an embodiment of the present invention.
[0017]
An inspection apparatus (hereinafter simply referred to as an apparatus) K is an inspection apparatus that inspects a joint L of a test material made of two members W1 and W2 using ultrasonic waves, and the illustrated example is a rotor for a turbocharger made of steel. The case where a joint portion L (hereinafter referred to as a joint surface) is inspected by brazing between the shaft W1 and the rotor blade W2 made of a titanium aluminum alloy (see FIG. 3) is shown.
[0018]
Here, the shaft W1 has a short-axis large-diameter portion 1 formed at an end portion on the joint surface L side and a long-axis small-diameter portion 2 following the short-axis portion. A joint surface parallel portion (hereinafter referred to as an incident surface) 3 which is a surface parallel to the joint surface L is formed relatively close to the joint surface L.
[0019]
Further, the apparatus K is to inspect by dividing the joint surface L into a plurality of regions V1, V2, V3, and V4 (see FIG. 2) in order to improve the inspection accuracy.
[0020]
Specifically, the apparatus K has an ultrasonic transmitter / receiver and outputs a signal corresponding to the sound pressure of the received ultrasonic wave to the reflection member 21 described later so as to switch the region to be inspected. An incident angle adjusting unit 20 that adjusts the incident angle of the ultrasonic waves, a member rotating unit 30 that rotates the members W1 and W2 so as to scan each point in the region V1, V2,..., And members W1 and W2. Is controlled so as to be rotated by the member rotating unit 30 at a fixed position, a sensor control unit 50 for controlling the sensor 10, the incident angle adjusting unit 20 and the member rotating unit 30 and sensor control. A determination processing unit 60 that receives an output signal of the sensor 10 via the unit 50 and performs predetermined signal processing on the output signal to determine whether or not there is a defect in the joint L. It becomes a as.
[0021]
As the sensor 10, a point focus type ultrasonic sensor that makes an ultrasonic wave perpendicularly incident on the bonding surface L is used in order to realize an inspection with a desired accuracy. However, since the width of the incident surface 3 is narrow on the axis W <b> 1, it is difficult to arrange the sensor 10 so that the ultrasonic wave is directly incident at an angle close to perpendicular to the incident surface 3. For this reason, the sensor 10 is disposed on the side of the axis W1, and the ultrasonic wave traveling direction is switched on the reflective surface 21a of the reflective member 21, so that the ultrasonic incident angle and path length are maintained appropriately. The regions V1, V2,... To be inspected can be switched.
[0022]
Here, as shown in FIG. 2, the regions V <b> 1, V <b> 2,... Are formed by dividing a circular joining portion L based on the distance from the center. That is, the pass / fail judgment conditions (determination reference values) T1, T2,... That judge the pass / fail of the joint L in correspondence with the incident conditions (incident angles in the embodiment) A1, A2,. The joint portion L is divided to be set. This is because, as will be described later, the incident angle of the ultrasonic wave at each point changes according to the distance from the center of the joint L, and the ultrasonic reflection characteristics change accordingly.
[0023]
As shown in FIG. 3, the incident angle adjusting unit 20 has an axis passing through the point P and perpendicular to the axis W1 so that the sensor 10 adjusts the incident angle at which the ultrasonic wave is incident on the point P on the reflecting surface 21a. At the center, the sensor 10 is a support mechanism that supports the sensor 10 so that the angle can be adjusted within a predetermined angle range (for example, between 10 ° above the horizontal direction and 30 ° below the horizontal direction).
[0024]
More specifically, as shown in FIG. 4, the incident angle adjusting unit 20 is a sickle-like flat plate member 22 in which an arm member 24 is provided at one end of an arc-shaped member 23 toward the center O, and the arm The sensor 10 is disposed at an appropriate position of the member 24, and the pinion 25 a mounted on the drive shaft of the drive motor 25 is engaged with the rack 23 a formed on the outer peripheral surface of the arc-shaped member 23 to rotate the center O around the center O. It is supposed to be made to rotate. Thereby, the angle of the sensor 10 can be adjusted with high accuracy. In addition, the double-headed arrow symbol in FIG. 4 shows a rotation direction.
[0025]
The member rotating unit 30 is a rotating mechanism that holds the shaft W1 at the end of the small-diameter portion 2 and rotates the shaft W1 so as to scan the regions V1, V2,.
[0026]
As shown in FIG. 5, the positioning portion 40 has a positioning hole 41 through which the small diameter portion 2 of the shaft W <b> 1 is inserted, thereby removing the shaft runout of the shaft W <b> 1 rotated by the member rotating portion 30. The The shaft passing through the positioning hole 41 is held with high accuracy by the member rotating unit 30 having a collet (not shown). In addition, the reflecting member 21 having the reflecting surface 21a is integrally assembled to the positioning portion 40.
[0027]
More specifically, the positioning part 40 is a rectangular parallelepiped in which one corner is removed at an angle of 45 degrees, for example, in a state where the reflecting member 21 and the positioning part main body 42 are combined. Further, the reflecting member 21 and the positioning portion are formed so that the reflecting surface 21a of the reflecting member 21 forms an intermediate portion of the inclined surface 40a formed by removing the corner portion, and the positioning hole 41 opens at the end of the reflecting surface 21a. Grooves 21 b and 42 a having a semicircular cross section are provided on the opposing surface of the main body 42, and the positioning holes 41 are formed by combining them.
[0028]
With this configuration, it is possible to set the position of the reflection point P so that the ultrasonic wave is incident at an angle close to perpendicular to the incident surface 3, and the inspection accuracy is improved. Moreover, the reflection member 21 is configured to be held independently of the positioning portion 40, thereby reducing the influence of vibration accompanying the rotation of the test material. Here, the reflecting surface 21a is preferably a mirror surface so that incident ultrasonic waves are efficiently reflected in a predetermined direction.
[0029]
The sensor control unit 50 controls the sensor 10 so that the sensor 10 emits ultrasonic waves having a predetermined frequency and sound pressure. In addition, the sensor control part 50 can use suitably the output control apparatus of the ultrasonic sensor conventionally used for the ultrasonic flaw detection.
[0030]
The determination processing unit 60 performs a determination process for determining the quality of the joint L based on the output signal of the sensor 10. Hereinafter, the determination process will be described.
[0031]
The determination process uses two reference values (threshold values) for each of the regions V1, V2,..., And the sound pressure (reflected echo height) of the reflected ultrasonic waves detected by the sensor 10, for example, is one threshold value (hereinafter referred to as coupling). If it is less than the error threshold, it is determined that a coupling error has occurred in which the ultrasonic wave does not reach the joint L to be inspected. On the other hand, when it exceeds the other threshold (hereinafter referred to as pass / fail judgment threshold), it is determined that there is a bonding failure.
[0032]
As described above, the apparatus K according to the embodiment forms the fixed reflection surface (reflector) 21a together with the positioning unit 40 so that the reflecting member 21 is integrally assembled with the positioning unit 40, and the inspection target region of the joint portion L is formed. The incident angle adjustment unit 20 adjusts the incident angle of the ultrasonic wave incident on the reflecting surface 21a from the sensor 10 so as to switch between V1, V2,..., And scans the ultrasonic wave at each point in the region V1, V2,. As described above, the members W1 and W2 are rotated by the member rotating portion 30.
[0033]
With this configuration, for example, ultrasonic waves are incident on the joint L between the rotor blade W2 made of, for example, a titanium aluminum alloy and the steel shaft W1 from a direction close to vertical by a point focus method, and each inspection object of the joint L is inspected. It becomes possible to inspect the entire joint L using a reference value set for each region so as to eliminate the influence due to the difference in the incident condition at the point.
[0034]
Therefore, it is possible to inspect the entire joining portion L with a desired high accuracy, and a sufficient inspection accuracy can be achieved even in a traffic machine such as an automobile in which safety is particularly important.
[0035]
【Example】
Hereinafter, the present invention will be described in more detail with reference to more specific examples.
[0036]
As shown in FIG. 6, the rotor shaft W1 and the rotor blade W2 similar to those of the embodiment are joined at the joint portion L, and the root portion of the rotor blade W2 is cut along a parallel plane M in the vicinity of the joint surface L. A material W3 was formed, and the joint L of the test material W3 was inspected by the apparatus K of the embodiment so as to be divided into regions V1, V2, V3, and V4.
[0037]
As shown in FIG. 6A, the plane M of the test material W3 is divided corresponding to the regions V1 to V4 of the joint L, and the inspection characteristics of the apparatus K are confirmed in each of the regions V1 to V4. 1 mm diameter flat bottom holes N1, N2, N3, and N4 are provided to simulate the defect.
[0038]
FIG. 7 shows the result as an example. Here, FIG. 7A shows the inspection result of the region V1, that is, the graph showing the height of the reflected echo at each position in the circumferential direction of the region V1, and FIG. 7B shows the inspection result of the region V2. 7C shows the inspection result of the region V3, and FIG. 7D shows the inspection result of the region V4.
[0039]
As shown in FIG. 7, detection signals appear at the corresponding positions of the flat holes N1 to N4. In particular, in FIGS. 7B, 7C, and 7D, more prominent detection signals N11, N12, and N13 are shown. However, it can be seen that defects appear in the respective regions V2, V3, and V4 of the joint portion L.
[0040]
Therefore, it is possible to detect a defect in the joint L by using the apparatus K.
[0041]
【The invention's effect】
As described above in detail, according to the joint inspection method of the present invention, the joint inspection area is divided into a predetermined number of concentric circular areas, and a determination criterion is provided for each of the divided areas. Therefore, an excellent effect of improving the inspection accuracy of the joint can be obtained.
[0042]
Further, according to the joint inspection apparatus of the present invention, the joint can be inspected from the vertical direction with high accuracy even in an inspection object that is inherently difficult to probe from the vertical direction, such as the joint on the shaft end surface. An excellent effect is obtained.
[Brief description of the drawings]
FIG. 1 is a functional block diagram illustrating an inspection apparatus to which a bonding portion inspection method according to an embodiment of the present invention is applied.
FIG. 2 is a cross-sectional view schematically showing the principle of region division of a joint to be inspected.
FIG. 3 is a side view showing an operation mode of an incident angle adjusting unit.
FIG. 4 is a schematic diagram of an incident angle adjustment unit.
FIG. 5 is a perspective view showing a positioning portion.
FIG. 6 is a two-side view showing a test material used in a more specific example of the present invention.
FIG. 7 is a graph showing an inspection result obtained by inspecting a test material.
FIG. 8 is a schematic diagram showing an example of a conventional method for inspecting a joint portion.
FIG. 9 is a schematic diagram showing a problem of the method.
FIG. 10 is a schematic diagram illustrating another example of a conventional method for inspecting a joint portion.
FIG. 11 is a schematic diagram showing a problem of the method.
[Explanation of symbols]
K inspection device L joint surface V region W member 1 large diameter portion 2 small diameter portion 3 joint surface parallel portion, incident surface 10 sensor 20 incident angle adjusting unit 21 reflecting member 21a reflecting surface 30 member rotating unit 40 positioning unit 50 sensor control unit 60 Judgment processing part

Claims (1)

An ultrasonic sensor that injects ultrasonic waves into the joint surface of the test material ;
Incident having a reflecting surface that reflects ultrasonic waves from the ultrasonic sensor to the joint surface, and a support mechanism that supports an incident angle from the ultrasonic sensor to the reflecting surface so that the angle can be adjusted within a predetermined angle range. An angle adjustment section;
A member rotating unit that rotates the test material so that ultrasonic waves incident from the ultrasonic sensor scan in the circumferential direction ;
A positioning part for removing shaft runout so that the test material is rotated at a predetermined position;
A sensor control unit for controlling the ultrasonic sensor;
A determination processing unit for determining a joint from the output of the ultrasonic sensor,
The incident angle adjusting unit adjusts the incident angle so that ultrasonic waves incident on the joint surface from the ultrasonic sensor scan concentrically , and switches the region to be inspected .
The bonding portion inspection apparatus , wherein the determination processing unit determines whether or not the bonding portion is good based on a threshold value set for each region .

Images