JPH022928A - Centering method for ultrasonic wave flaw detecting jig - Google Patents

Abstract

PURPOSE:To make it possible to perform centering simply, quickly and accurately and to make it possible to perform inspecting operation efficiently and highly accurately by providing a movable state for at least one of a probe holder or a work holder. CONSTITUTION:At least one of a probe holder 6 or a work holder 10 is made to be in a movable state. A shaft part 17a which can be coupled into the holding shaft hole of a probe 5 in the holder 6 is made concentric with a shaft part which is coupled into an attaching shaft hole 15a of a work guide 15 in the holder 10. Linked centering rods are inserted into both shaft holes. Thereafter the holder 6 or the holder 10 is fixed. A shaft hole 6a which holds the probe 5 and the shaft hole 15a of the guide 15 which holds a shaft part 17a of a work 17 are made concentric by the insertion of the centering rod. Therefore, the central line of the probe 5 which is held with the holder 6 and the central line of the shaft part 17a of the work 17 which is held with the guide 15 agree. When the sizes of the shaft parts are changed depending on the kinds of works and the corresponding guide 15 is replaced, off-centering state from the probe 5 does not occur. Therefore, it is not required to perform centering again.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is used to inspect internal defects in welds in workpieces having welds on the shaft, such as engine valves, using an ultrasonic flaw detector. Regarding the centering method of the jig.

[Conventional technology]

The shaft ends of the valve stems in engine valves are subjected to strong forces from cams and rocker arms during intake and exhaust, so they must be heat-treated, such as induction hardening, to increase their hardness and provide excellent wear resistance.

One way to increase the hardness of the shaft end is to weld a martensitic tip, which has high hardness through quenching and has excellent wear resistance, to the shaft end.

The engine valve thus completed is usually inspected for welding defects using an ultrasonic flaw detector.

In this case, in order to improve flaw detection accuracy, it is necessary to perform centering so that the center of the probe in the ultrasonic flaw detector and the center of the shaft of the workpiece are on the same straight line.

Conventionally, this centering was performed by holding the workpiece with a jig that was slidable on the base and adjusting the jig while directly observing the reflected waveform on the cathode ray tube of the ultrasonic flaw detector. .

[7!1 Problems to be Solved by the Invention] In the above method, the centering work is troublesome and inefficient. In particular, in the water immersion flaw detection method with high flaw detection accuracy, the probe, Since the workpiece and the jig are partially submerged in water, it is necessary to put one's hand into the water each time an adjustment is made, further worsening work efficiency.

Furthermore, when the type and dimensions of the workpiece change, the centering work must be restarted from the beginning each time, making the work complicated.

The present invention has been made to solve the above problems, and is an ultrasonic flaw detection jig that can perform centering work quickly and accurately regardless of the type and size of the workpiece. The purpose is to provide a method.

[Means for Solving the Problems] In order to achieve the above object, the present invention consists of a probe boulder that holds a probe, and a work holder that has a work guide that can hold the shaft of the work. In the method for centering the probe and the work shaft in an ultrasonic flaw detection jig, holding the probe in the probe holder after at least one of the probe holder or the work holder is in a movable state. A shaft part that can be fitted into the shaft hole and a shaft part that can be fitted into the shaft hole are connected concentrically, and a centering rod is passed through both the shaft holes, and the work guide is installed in the work holder. After that, the probe holder or work holder is fixed.

[For production]

According to the present invention, the shaft hole that holds the probe and the shaft hole of the work guide that holds the shaft portion of the workpiece become concentric due to the penetration of the centering rod, so that the shaft hole that holds the probe is held in the probe holder. The central axes of the probe and the shaft portion of the workpiece held by the workpiece guide inevitably coincide.

Additionally, even if the shaft dimensions change depending on the type of workpiece and the workpiece guide is replaced with a compatible workpiece guide, the probe will not be misaligned, and there is no need to re-center it. .

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

Figure 2 shows the jig (1) used for water immersion ultrasonic flaw detection.
The figure shows a partially broken part of the workpiece. During measurement, the non-inspection side of the workpiece and part of the jig (1) are placed on the surface of the water tank (2) (2a ), and most other parts are immersed in water.

A base (3) in the jig (1) is supported almost horizontally by four bolts (4) attached to its bottom surface.

On the front upper surface of the base (3), there is a probe holder (6) that holds a probe (5) connected to an ultrasonic flaw detector (not shown).
However, also in the central part, a support block (7) having a downwardly inclined surface (7a) of approximately 45'' in the front part is provided so as to be slidable in the front and rear directions.

Mounting part (6) of the probe (5) in the probe holder (6)
In a), the center axis of the probe (5) is aligned with the support block (7).
) is slightly tilted forward so as to be parallel to the inclined surface (7a) at the top.

As shown in the fourth diagram, the support block (7) has a prismatic protrusion (7b) formed at the center of its bottom face and facing in the front-rear direction.
and a groove (3) in the front-rear direction formed on the top surface of the base (3).
a) are closely fitted to restrict movement in the left and right direction, and are supported from below in the longitudinally long elongated holes (8) (8) drilled in both left and right sides of the base (3). Block (7)
By loosening a pair of left and right fixing bolts (9) screwed into the bottom surface of the body, the body can be slid in the front and back direction while being guided by the groove (3a).

A work holder (10) is attached to the inclined surface (7a) of the support block (7).

As shown in the third figure, the work holder (lO) has a protrusion (loa) formed in the center of its bottom surface and facing in the front-rear direction.
By tightly fitting into a groove (11) facing in the front-rear direction provided on the inclined surface (7a), it is possible to slide in the front-rear direction.

In addition, as mentioned above, the support block (7) and the work holder (lO) are connected to the protrusions (7b) and (10a), respectively.
By regulating the movement in the left and right direction with the recesses 2V (3a) and (11), the center axis of the probe (5) and
If the center axis of the shaft of the workpiece (described later) is aligned in advance, the support block (7) and workpiece holder (10)
Even when the two are moved, it is possible to prevent their central axes from shifting in the left-right direction.

The bolt (12) inserted from above the long hole (13) in the longitudinal direction provided in the side-facing flange (10b) (10b) connected to the lower part of the work holder (10) is inserted into the support block (7). The work holder (10) is fixed by screwing onto the inclined surface (7a) in ).

The probe holder (
The shaft hole (6b) drilled in the mounting part (6a) in 6)
A downwardly sloping axial hole (14) concentric with the shaft hole (14) is drilled therein.

A cylindrical work guide (15) having a guide hole (15a) in the center is fitted into the shaft hole (14), and a bolt (16) (1
6), the extraction is stopped.

The upper opening end of the guide hole (15a) is tapered and chamfered to facilitate insertion of the shaft portion (17a) of the engine valve (17), which is a workpiece.

The middle part of the work holder (10), that is, the shaft hole (14)
A female threaded hole (18) whose center axis intersects the center axis of the work guide (15) above is bored immediately below the workpiece guide. A stopper bolt (19) is inserted through this female threaded hole (18).

The engine pal (17) inserted from above into the guide hole (15a) in the work guide (15) has its umbrella part (
The lower surface of the stopper bolt (17b) abuts against the upper end of the stopper bolt (19), thereby being fixedly held.

In this case, the dimension between the tip surface of the shaft portion (17a), that is, the tip surface of, for example, a martensitic chip (17c) welded to the shaft end, and the probe (5) is set to a predetermined dimension. There is a need to. To make this adjustment, first use the work holder (
10) to determine the approximate dimensions, and then adjust the protruding length of the stopper bolt (19).

Next, referring to FIG. 1, the procedure for centering the jig will be explained.

As mentioned above, the support block (7) and work holder (
10) is prevented from moving in the left-right direction, so the central axis between the probe (5) and the shaft portion (17a) of the workpiece is
Since they match each other in the left-right direction, it is only necessary to align them in the front-back direction.

After temporarily fixing the work holder (10) to an appropriate position on the support block (7), remove the work guide (15) and stopper bolt (19) from the work holder (10), and remove the work guide (15) and stopper bolt (19) from the probe holder (6). Remove the probe (5).

Next, after loosening the fixing bolt (9) of the support block (7), insert the shaft portion (20a) that can fit tightly into the shaft hole (14) of the work guide (15), and the shaft portion (20a). A centering rod (zO), which is connected to the tip and has a shaft portion (20b) with a slightly smaller diameter that can fit tightly into the shaft hole (6a) of the probe holder (6), is attached to the work holder. (10) into the shaft hole (14) from diagonally above.

At the same time, slide the support block (7) in the front-back direction to align the shaft portion (20b) and the shaft hole (6a), and then until the shaft portion (20b) passes through the shaft hole (6a). insert.

In this state, fix the support block (7) and center the centering rod (2).
0).

Finally, when the probe (5), work guide (15) and stopper bolt (19) are attached, the centering work is completed.

As a result, the shaft portion (17a) of the engine valve (17) set in the work guide (15) and the probe (5)
The axes of the shaft portion (17a) and the shaft portion (17a) are precisely aligned, and the perpendicularity of the end face of the shaft portion (17a) with respect to the probe (5) is maintained.

Therefore, internal defects in the welded portion (W) of the chip (17c) can be measured with high flaw detection accuracy.

Once centering is performed according to the above procedure, even if the shaft diameter changes depending on the type of workpiece, the workpiece guide (I
5), there is no need to center again, just by replacing
Also, the work holder (10) or stopper bolt (19)
Even when the distance between the probe (5) and the shaft portion (17a) is adjusted to a predetermined dimension by moving the probe (5), there is no risk of mutual misalignment.

In the embodiment, a case where an inclined type jig is used in consideration of workability has been described, but it goes without saying that the present invention can also be applied to a horizontal type jig.

〔Effect of the invention〕

According to the present invention, not only can centering be performed easily, quickly, and accurately, but if the centering is performed only once at the beginning, there is no need to perform centering again even if the type or size of the workpiece changes. So, do some inspection work.

This can be done efficiently and with high precision.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the centering state of a jig according to an embodiment of the present invention. FIG. 2 is a partially cutaway side view showing an embodiment of a jig to which the present invention is applied. Figure 3 shows the 1st IJ! A longitudinal sectional front view of the main part along the line XX in J. Figure 4 is a longitudinal sectional front view of the main parts along the same <YY line.6 (1) Jig (3) Base (4) (9) (12) (16) Bolt (6) Probe Child holder (7) Support block (7b) (10a) Projection (10) Work holder (15) Work guide (17) Engine valve (17b) Umbrella (18) Female threaded hole (20) Centering stud (W) Welded part (2) Water tank (3a) (11) Concave groove (5) Probe (6b) (t4) Shaft hole (7a) Inclined surface (8) (13) Long hole (10b) Flange part (15a) Guide Hole (17a) Shaft (17c) Chip (19) Stopper bolt (20a) (20b) Shaft Fig. 1

Claims (1)

[Claims] The probe and the work shaft in an ultrasonic flaw detection jig comprising a probe holder that holds a probe and a work holder that has a work guide that can hold the work shaft. In the centering method, after setting at least one of the probe holder or the work holder to a movable state, a shaft portion that can fit into a holding shaft hole of the probe in the probe holder, and a shaft portion of the work holder that can fit into the holding shaft hole of the probe; A centering rod, which is connected concentrically with a shaft portion that can fit into the mounting shaft hole of the work guide, is passed through both shaft holes, and then the probe holder or the work holder is fixed. Features: Centering method for ultrasonic flaw detection jigs.