KR20100071341A - Dual type ultrasonic sensor for adjusting focal length - Google Patents

Abstract

PURPOSE: A divided ultrasonic sensor capable of adjusting focus depth is provided to control the sensitivity of a depth direction by adjusting the focus depth of a beam by geometrically bonding a plurality of delay members to the lower part of a piezoelectric vibrator. CONSTITUTION: A divided ultrasonic sensor capable of adjusting focus depth comprises an acoustic sound division plane(20), a piezoelectric vibrator(50), a transmit delay member(11) and a delay member. The acoustic sound division plane is formed perpendicularly to the center. The piezoelectric vibrator comprises a transmitter(51) and a plurality of receivers. The transmitter is formed at one side of the acoustic sound division plane to slope. The receivers are formed at the other side of the acoustic sound division plane to slope. The transmit delay member is formed at the lower part of the transmitter. The delay member comprises the receive delay member(12) formed at the lower part of the receiver. The receive delay member comprises a first transmit delay member and a second transmit delay member.

Description

Dual type ultrasonic sensor for adjusting focal length}

The present invention relates to a split type ultrasonic sensor capable of adjusting the depth of focus, and more particularly, to a split type ultrasonic sensor capable of adjusting the depth of focus to improve the depth of focus while having the same ultrasonic emission surface.

Recently, non-destructive ultrasonic sensors have been in the spotlight as stability diagnosis and prediction devices of facility structures. This is not to diagnose the mechanical characteristics and condition of the structure by the fracture test as in the prior art, but to diagnose the physical property and the operating state non-destructively by using ultrasonic waves, and it is possible to continuously diagnose the state of the structure and machinery in operation. It is possible to prevent sudden breakdown of machinery, which can prevent large equipment and work loss.

In addition, the non-destructive ultrasonic sensor can be easily installed in a complicated structure, which has been difficult to diagnose in the past, and has an advantage that an excellent diagnostic effect can be obtained at a much lower cost than other methods.

On the other hand, there are a variety of types of the ultrasonic sensor, the most widely used for quality inspection in the industrial field is a split type sensor. This is a form in which two piezoelectric vibrators are contained together in one enclosure, so that transmission and reception of ultrasonic waves can be performed by one sensor.

However, such a split type sensor has an advantage of ease of use and noise removal by combining a transmission / reception signal, but has an important defect of a narrow operating frequency band. In order to accurately detect even minute internal defects in the non-destructive inspection, the wider the frequency band used, the more advantageous it is. However, the conventional split type ultrasonic sensor generally does not exceed 50% of the band.

In order to solve this problem, Korean Utility Model Registration Publication No. 1997-0006841 (July 8, 1997) of the present applicant discloses a conventional split type ultrasonic sensor, and the conventional split type ultrasonic sensor has a predetermined frequency. It is an ultrasonic sensor having a structure that expands an operating frequency band by combining a transmitter that emits ultrasonic waves and a receiver that receives ultrasonic signals reflected from an object to be detected.

At this time, in order to focus the ultrasonic beam radiated from the transmitter at a certain depth, the transmitter and the receiver are inclined at a predetermined angle. This angle determines the sensitivity characteristic according to the depth of the ultrasonic beam.

In this case, the depth of focus is determined by the angle. As the sensitivity difference of the ultrasonic beam according to the depth is smaller, the sensitivity adjustment according to the depth can be made smoother in the automatic inspection system, and thus the noise effect can be blocked.

However, such a conventional ultrasonic sensor has a problem that the noise signal is amplified together because the difference between the sensitivity value at the focus point and the sensitivity value at the point away from the focus is much amplified.

1 is a block diagram showing a conventional split ultrasonic sensor, and as shown in FIG. 1, a retarder 1, an acoustic splitting surface 2, an electric wire 3, a backing member 4, and a transmitter Conventional split type ultrasonic sensor having a piezoelectric vibrator made of a receiver can adjust ultrasonic sensitivity in the depth direction by adjusting the angle of the transmitter and receiver, but cannot change the sensitivity value according to the depth. There was this.

The present invention has been made to solve the above-mentioned conventional problems, and by joining a plurality of retarders in a geometric shape, it is possible to adjust the depth of focus sensitivity by adjusting the depth of focus of the beam, and also the automatic of large area metal It is an object of the present invention to provide a split-type ultrasonic sensor with adjustable depth of focus that can increase the signal-to-noise ratio of the ultrasonic sensor during inspection, thereby improving the measurement accuracy of the entire system.

The present invention for achieving the above object is a piezoelectric vibrator having a sound split surface formed perpendicular to the center, a transmitter formed obliquely on one side of the sound split surface and a receiver formed obliquely on the other side of the sound split surface; A split type ultrasonic sensor including a delay delay member having a transmission delay member formed below the sender and a reception delay member formed below the receiver, wherein the transmission delay member is bonded to the first transmission delay member and the bottom surface thereof. And a second transmission delay material, wherein the reception delay material is comprised of a first reception delay material and a second reception delay material bonded to the lower surface thereof, and between the first transmission delay material and the second transmission delay material. The joining surface is curved so that its front end face is convex downward, and the joining surface between the first receiving delay material and the second receiving delay material has its front end convex downward. Songs are formed.

By changing the curvature of the joint surface of the present invention, the delay speed difference between the first transmission delay member and the second transmission delay member, and the delay speed difference between the first reception delay member and the second reception delay member, the division type The depth of focus of the ultrasonic sensor is adjusted.

As described above, the present invention provides an effect of controlling the depth direction sensitivity by adjusting the depth of focus of the beam by bonding a plurality of retarders in a geometric shape to the lower portion of the piezoelectric vibrator.

In addition, it is possible to increase the signal-to-noise ratio of the ultrasonic sensor during the automatic inspection of large area metal, thereby improving the measurement accuracy of the entire system.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

2 is a block diagram showing a split type ultrasonic sensor capable of adjusting the depth of focus according to an embodiment of the present invention, Figure 3 is a side view showing a split type ultrasonic sensor capable of adjusting the depth of focus according to an embodiment of the present invention. .

As shown in Figures 2 and 3, the split type ultrasonic sensor that can adjust the depth of focus of the present embodiment comprises a retarder, a sound split surface 20, a piezoelectric vibrator 50, the wire 30, the rear The ash 40 and the bonding material 60 are the same as the conventionally known configurations, and of course, they may be further included.

The retarder is formed under the piezoelectric vibrator 50 and is used to eliminate dead bands in the split type ultrasonic sensor. A plurality of retarders are formed in a geometric shape for controlling the depth of focus of the ultrasonic beam by adjusting the size of the beam in the left and right directions. do.

That is, the delay member includes a transmission delay member 11 formed at one lower portion of the piezoelectric vibrator 50 and a reception delay member 12 formed at the other lower portion of the piezoelectric vibrator 50. As the material of such a retardant, it is possible to use acrylic resin, alumina, polystyrene, or the like.

The transmission delay material 11 consists of the 1st transmission delay material 11a, the 2nd transmission delay material 11b joined to the lower surface, and the joining surface 11c between them. As for the joining surface 11c between the 1st transmission delay material 11a and the 2nd transmission delay material 11b, the front end surface is curved convexly downward. It is also possible that the front end face is formed in an arc shape.

The reception delay member 12 includes a first reception delay member 12a, a second reception delay member 12b bonded to the bottom surface thereof, and a bonding surface 12c therebetween. The joining surface 12c between the first reception delaying member 12a and the second reception delaying member 12b is curved at its front end convex downward. It is also possible that the front end face is formed in an arc shape.

3, the side surface of the joining surfaces 11c and 12c of each retarder is formed in linear shape.

The sound split surface 20 is formed perpendicular to the center to acoustically separate the piezoelectric vibrator 50 into a transmission area and a reception area. The wire 30 is connected to the piezoelectric vibrator 50 to apply external electrical energy to the vibrator. The rear surface material 40 is formed on the rear surface of the piezoelectric vibrator 50 to attenuate the ultrasonic beam radiated from the rear surface.

The piezoelectric vibrator 50 is an oscillator for generating ultrasonic vibration, and includes a transmitter 51 formed inclined on one side of the sound splitting surface 20 and a receiver 52 formed inclined on the other side of the sound splitting surface 20.

Piezoelectric vibrator 50 is a wire terminal is connected to one side of the hollow closed type sheath, the wire terminal is a transmitter that is divided into an acoustic split surface 20 by extending the wire 30 to the inside of the back member 40 And a receiver 52.

Therefore, when an external electric signal is applied to the transmitter 51, ultrasonic waves are generated by the transmitter 51, the ultrasonic waves are reflected on the test piece through the radio wave path, and then returned to the receiver 52. Contains information about the internal defects of the specimen.

The bonding material 60 is formed between the retardation material and the piezoelectric vibrator 50 to maintain the adhesion therebetween. It is possible to use the same material as the retardation material or use an epoxy resin or the like.

In addition, the split type ultrasonic sensor of the present embodiment has a curvature of the joint surfaces 11c and 12c of each delay member, a delay speed difference between the first transmission delay member 11a and the second transmission delay member 11b, and the first. By changing the delay speed difference between the reception delay member 12a and the second reception delay member 12b, the depth of focus of the split type ultrasonic sensor is adjusted.

That is, the split type ultrasonic sensor of the present embodiment bonds a retarder and a piezoelectric vibrator having a special geometric shape using epoxy, and adjusts the curvature of the cross section formed on the joint surface between the plurality of retarders and the sound speed of each retarder. The depth sensitivity of the ultrasonic beam can be adjusted.

4 is a graph illustrating a measurement result of a beam size according to a depth direction in a split type ultrasonic sensor and a conventional ultrasonic sensor that can adjust the depth of focus according to an exemplary embodiment of the present invention.

As shown in FIG. 4, the beam intensity of the ultrasonic sensor according to the present embodiment is smaller than that of the conventional ultrasonic sensor due to the two retarders, but the variation in the beam intensity, that is, the difference in the change in the vertical direction is reduced than in the prior art. The sensitivity of the ultrasonic wave in the depth direction is improved.

The present invention described above can be embodied in many other forms without departing from the spirit or main features thereof. Therefore, the above embodiments are merely examples in all respects and should not be interpreted limitedly.

1 is a block diagram showing a conventional split ultrasonic sensor.

Figure 2 is a block diagram showing a split type ultrasonic sensor capable of adjusting the depth of focus according to an embodiment of the present invention.

Figure 3 is a side view showing a split type ultrasonic sensor capable of adjusting the depth of focus according to an embodiment of the present invention.

Figure 4 is a graph showing the measurement results of the beam size according to the depth direction in the conventional ultrasonic sensor and the split type ultrasonic sensor capable of adjusting the depth of focus according to an embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

11: Transmission delayer 12: Reception delayer

20: acoustic splitting surface 30: electric wire

40: backing material 50: piezoelectric vibrator

51: sender 52: receiver

60: bonding material

Claims (2)

A piezoelectric vibrator having a sound splitting surface formed vertically in the center, a transmitter formed obliquely on one side of the sound splitting surface, and a receiver formed obliquely on the other side of the sound splitting surface, a transmission delay member formed under the transmitter and the receiver In the split type ultrasonic sensor comprising a retarder having a receiving delay formed on the bottom of the, The transmission delay material is composed of a first transmission delay material and a second transmission delay material bonded to the lower surface, and the reception delay material is composed of a first reception delay material and a second reception delay material bonded to the lower surface. , The joint surface between the first transmission delay member and the second transmission delay member has a forward end face convexly curved, and the bonding surface between the first reception delay member and the second reception delay member is Depth-adjustable split type ultrasonic sensor, characterized in that the front end is curved convex downward. The method of claim 1, Depth of focus by changing the curvature of the joint surface, the delay speed difference between the first transmission delay member and the second transmission delay member and the delay speed difference between the first reception delay member and the second reception delay member Depth-type split ultrasonic sensor, characterized in that for adjusting the depth of focus.

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