JPH02183158A - Ultrasonic probe - Google Patents

Abstract

PURPOSE:To enable accurate prevention of breakage of material to be inspected and an acoustic lens by detecting a force working on a stopper with a force detector. CONSTITUTION:This device is provided with an element to radiate an ultrasonic wave while converting reflected wave thereof into an electrical signal, a holder 1 for holding the element, an acoustic lens 2 fixed with the tip thereof sticking to the holder 1 and a stopper 4 which has the tip thereof slightly protruding from the tip of the acoustic lens 2 as mounted on the holder 1. A force detector is provided to detect a force working on the stopper 4. When the tip of the stopper 4 gets in contact with a material to be inspected during the adjusting of a focus or because of an accident to cause a pressing force between the both, the pressing force is detected by the force detector. When the pressing force detected reaches a predetermined value, an ultrasonic probe is stopped or retracted, thereby enabling prevention of a breakage of the material to be inspected and the acoustic lens 2.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an ultrasonic inspection device that uses ultrasonic waves to inspect a specimen. Regarding the probe.

[Conventional technology]

2. Description of the Related Art An ultrasonic inspection device is a device that performs various inspections such as the presence or absence of defects inside a material to be inspected by irradiating a material to be inspected with ultrasonic waves and analyzing the reflected waves. In such an ultrasonic inspection apparatus, an ultrasonic probe emits ultrasonic waves and receives reflected waves thereof. The ultrasonic probe will be explained below using figures.

FIGS. 3(a) and 3(b) are a side view and a bottom view of the ultrasonic probe. In each figure, 1 is a holder, 2 is an acoustic lens fixed to the holder l, 3 is a connector, and 4 is a stopper fixed to the holder 1. A piezoelectric transducer element is housed in the holder 1, which is excited when a voltage is applied to emit an ultrasonic wave, and converts the incident ultrasonic wave into an electric signal according to its magnitude. The connector 3 is a connection terminal for applying voltage to the piezoelectric conversion element and outputting the electric signal. The acoustic lens 2 protrudes from the holder 1 and has the function of converging the ultrasonic waves emitted from the piezoelectric transducer to a focal point, and transmitting the reflected waves to the piezoelectric transducer in parallel. The stopper 4 is made of an elastic body such as rubber or soft plastic, and is provided surrounding the acoustic lens 2, with its tip protruding slightly (several μm to several lOμm) from the tip of the acoustic lens 2.

When inspecting a material to be tested, the material to be tested is placed in water, an ultrasonic probe is placed opposite the material to be tested, and ultrasonic waves are transmitted and received through the water between the two. In this case, the ultrasonic probe is moved up and down to adjust the focus of the ultrasonic waves to a desired location on the specimen. In many cases, the ultrasonic probe is adjusted to such an extent that the tip of its acoustic lens 2 comes into contact with the surface of the specimen. The stopper 4 is provided to prevent the expensive acoustic lens 2 from coming into contact with the test material and being damaged during such adjustment. That is, since the tip of the stopper 4 slightly protrudes from the tip of the acoustic lens 2, when the ultrasonic probe is adjusted to approach the material to be examined, the tip of the stopper 4 is slightly protruded from the tip of the acoustic lens 2, so when the ultrasonic probe is adjusted to approach the material to be inspected, the tip of the stopper 4 is slightly extended before the acoustic lens 2 comes into contact with the material to be inspected. The stopper 4 comes into contact with the material to be inspected, thereby preventing the acoustic lens 2 from being damaged.

[Problem to be solved by the invention]

By the way, when adjusting the focus of the ultrasonic probe, there is an accident in which the ultrasonic probe is brought too close to the material to be inspected, resulting in the stopper 4 pressing against the material to be inspected and damaging it. It happened often. Furthermore, at this time, a strong pressing force is applied to the stopper 4, causing deformation of the stopper 4 and causing the tip of the acoustic lens 2 to protrude beyond the tip of the stopper 4, causing the acoustic lens 2 to come into contact with the material to be inspected and be damaged. Accidents also occurred. These accidents occur not only during focus adjustment, but also when
This accident can also occur when the ultrasound probe accidentally moves downward for some reason.

The purpose of the present invention is to solve the problems in the above-mentioned prior art,
An object of the present invention is to provide an ultrasonic probe that can reliably prevent damage to a test material or an acoustic lens.

[Means to solve the problem]

In order to achieve the above object, the present invention provides an element that emits ultrasonic waves and converts the reflected waves into electrical signals, a holder that houses this element, and an acoustic lens that is fixed to the holder with its tip protruding. and a stopper attached to the holder and having a tip slightly protruding from the tip of the acoustic lens, further comprising a force detector for detecting a force acting on the stopper. do.

(Function) When the tip of the stopper comes into contact with the test material when adjusting the focus of the ultrasonic probe or due to an accident, and a pressing force is generated between the two, this pressing force is detected by the force detector. By stopping or retracting the ultrasonic probe when the detected pressing force reaches a predetermined value, damage to the test material and the acoustic lens can be prevented.

〔Example〕

Hereinafter, the present invention will be explained based on illustrated embodiments.

FIG. 1 is a side view of an ultrasound probe according to an embodiment of the present invention. In the figure, the same parts as those shown in FIGS. 3(a) and 3(b) are designated by the same reference numerals, and the explanation thereof will be omitted. 5 is a piezoelectric body interposed between the holder l and the stopper 4. The configuration other than the piezoelectric body 5 is the same as that shown in FIGS. 3(a) and 3(b).

Next, the operation of this embodiment will be explained with reference to the output voltage characteristics of the piezoelectric body shown in FIG. In FIG. 2, the horizontal axis represents the force F acting on the piezoelectric body 5, and the vertical axis represents the output voltage V of the piezoelectric body 5. Here, let F be the allowable limit force in which the force F acting on the piezoelectric body 5 does not cause any damage to the test material and the stopper 4, and let the output voltage of the piezoelectric body 5 at this time be v3. . On the other hand, a control device (not shown) of the ultrasonic inspection apparatus is equipped with a function of constantly inputting the output voltage of the piezoelectric body 5 and comparing it with the voltage V mentioned above.

Here, it is assumed that the ultrasonic probe is brought close to the specimen to be examined for focus adjustment, and the tip of the stopper 4 comes into contact with the specimen. At the moment of this contact, the pressing force acting between the stopper 4 and the test material, ie, the force F acting on the piezoelectric body 5, is approximately zero. If, for some reason, the ultrasonic probe is moved further in the direction of the test material from this state, the force F acting on the piezoelectric body increases. Then, when the above movement is continued, the force F
increases accordingly and eventually reaches the force F.

At this time, the output voltage of the piezoelectric body 5 becomes the value V, and the control device outputs a signal after confirming that the output voltage has become the value V as a result of the above-mentioned comparison. Using this signal, the ultrasonic probe drive device is automatically stopped, or the ultrasonic probe is automatically moved backward by the drive device. This reliably prevents damage to the test material and the acoustic lens.

As mentioned earlier, this operation is performed in the same way when the ultrasonic probe moves due to an accident and the stopper 4 is pressed by the material to be inspected or another object. This is to prevent damage to the acoustic lens 4, other objects, etc.

In the above embodiments, an example in which force is detected using a piezoelectric body has been described, but the present invention is not limited to this, and for example, a normal load cell using a flexible beam may be used as a force detector. Further, a force detector such as a piezoelectric body may be provided at the tip of the stopper. Furthermore, it is clear that the set value V of the output voltage can be set to any value depending on the material of the material to be inspected, the acoustic lens, etc.

〔Effect of the invention〕

As described above, in the present invention, since the force acting on the stopper is detected by the force detector, damage to the test material and the acoustic lens can be reliably prevented.

[Brief explanation of the drawing]

FIG. 1 is a side view of an ultrasound probe according to an embodiment of the present invention;
FIG. 2 is an output voltage characteristic diagram of the piezoelectric material shown in FIG. 1, and FIGS. 3(a) and 3(b) are a side view and a bottom view, respectively, of a conventional ultrasonic probe. 1...Holder, 2...Acoustic lens, 3
...Connector, 4...Stopper, 5.
...Piezoelectric body. (a)

Claims (5)

[Claims] (1) An element that emits ultrasonic waves and converts the reflected waves into electrical signals, a holder that houses this element, an acoustic lens that is fixed to the holder with its tip protruding, and an acoustic lens that is attached to the holder and that An ultrasonic probe equipped with a stopper having a tip slightly protruding from the tip of a lens, characterized in that the probe is equipped with a force detector that detects the force acting on the stopper. (2) The ultrasonic probe according to claim (1), wherein the force detector is a piezoelectric element. (3) The ultrasonic probe according to claim (1), wherein the force detector is a load cell having a flexible beam. (4) The ultrasonic probe according to claim (1), wherein the force detector is provided between the stopper and the holder. (5) The ultrasonic probe according to claim (1), wherein the force detector is provided at the tip of the stopper.