JPS58612B2 - Container inspection equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a container inspection device, and particularly to a container inspection device that can quickly and reliably determine the quality of containers and the like.

Conventionally, the measurement or inspection of the internal pressure of sealed containers such as equipment (inspection of the quality of equipment) has been carried out using a so-called percussion test (hearing test) by striking the equipment.
Sensory testing (sensory testing) has been widely used, but in recent years, it has become possible to apply shocking electrical energy to containers such as equipment, vibrate the containers, and measure the energy distribution of various frequencies generated by the vibrations of the containers. A method of measuring and inspecting the quality of containers was proposed.

However, with this method, the energy distribution of various frequencies changes due to minute differences in the wall thickness of the container such as supplies, the tightness of the cap, etc. When applied to a container, harmful signals such as noise other than the resonant frequency of the container are also generated at the same time, so it is difficult to extract an accurate electrical signal that correlates with the internal pressure of a sealed container such as equipment. The conventional method has the disadvantage that accurate inspection is not possible.

Normally, noise cancellation, individual detection of energy at various frequencies, etc. require complex electrical processing, resulting in a long processing time.

Therefore, the above-mentioned conventional technology is not suitable for inspecting the quality of products such as fixtures flowing on a high-speed belt conveyor.

Therefore, the main object of the present invention is to propose a container inspection device that can quickly and reliably inspect the quality of containers such as equipment.

The present invention is characterized in that an ultrasonic transducer projects ultrasonic waves onto a test container, and the ultrasonic transducer receives reflected ultrasound modulated by the natural vibration of the test container. In a container inspection device that converts the
The ultrasonic transducer is arranged at a distance from the test container, and the ultrasonic wave emitted from the ultrasonic transducer is converted into an ultrasonic pulse that continues for an extremely short fixed period of time. The present invention relates to a container inspection device that projects an image onto an inspection container from one side.

Hereinafter, an example of a container inspection device according to the present invention will be explained with reference to the drawings.

FIG. 1 is a route map of an example of the container inspection device according to the present invention.
In the figure, reference numeral 1 denotes an ultrasonic transducer or transducer, which is made of, for example, barium titanate porcelain, crystal, or ferrite.

2 is an ultrasonic pulse generator, for example, about 50
~200MHz electric pulse signal, for example, transformer T
1 and the bridge circuit 3 to the transducer 1.

Then, as shown in FIG. 2A, the transducer 1 emits a beam-shaped ultrasonic pulse for a very short period of time, for example, 1 to 3 milliseconds.

This beam-shaped ultrasonic wave is projected onto a test material or container 4, such as equipment or a cloudy container.

At this time, the outer wall of the container 4 is energized by the ultrasonic waves and generates minute natural vibrations in correlation with its internal pressure. Modulated by vibration.

That is, ultrasonic waves as shown in FIGS. 2B and 2C are emitted from the container 4.

Normally, when the vacuum level of the sealed container 4 for equipment or cloudy packing is good (corresponding to a good product), the resonant frequency of the container 4 is high and therefore has a high Q; (corresponding to a product), the resonant frequency of the container 4 is low and therefore has a low Q.

That is, as shown in FIG. 2B, the ultrasonic waves modulated by the container 4, which has a good degree of vacuum and exhibits a high Q, have a high vibrational force (energy) and last for about several milliseconds, for example.

On the other hand, the ultrasonic waves modulated by the container 4 with poor vacuum and low Q have a lower vibration force (energy) than the ultrasonic waves shown in FIG. 2B, as shown in FIG. The ultrasound wave shown in B lasts for a shorter duration, eg, only about 2-3 milliseconds.

Therefore, by measuring the amount of energy of the ultrasonic waves modulated by the container 4, it is possible to determine whether the container 4 is good or bad.

Therefore, in the example of the invention shown in FIG. 1, the transducer 1 receives ultrasound modulated in the container 4,
This is converted into a corresponding electrical signal, and this electrical signal is supplied to the detection circuit 6 via the bridge circuit 3, transformer T2 and amplifier 5, and its energy is detected.

Next, the output of this detection circuit 6 is supplied to a quality determination circuit 7, where it is compared with a predetermined reference value (threshold value), that is, an energy value corresponding to a non-defective product, and the quality of the container is determined. do.

In the present invention, ultrasonic waves having a certain time duration as shown in FIG. 2A are supplied from an ultrasonic pulse generator 2 to a transducer 1 via a transformer T1 and a bridge circuit 3. , the amplifier 5 is not supplied with the pulse signal from the ultrasonic pulse generator 2, and the transducer 1 receives the ultrasonic wave modulated by the container 4, and only the corresponding electrical signal from this is sent to the bridge. Via circuit 3 and transformer T2,
Of course, it is supplied to the amplifier 5.

In FIG. 1, 31 is an equivalent circuit for balancing the bridge.

Note that even if the bridge circuit 3 is not used and a circuit configuration is used that stops the operation of the amplifier 5 while the transducer 1 is emitting ultrasonic waves, the same effect as described above can be obtained. Furthermore, the same result can be obtained even if a circuit configuration in which two transducers are separately provided for ultrasonic transmission and ultrasonic reception is used instead of one transducer 1. It is effective.

Furthermore, even when sequentially inspecting containers 4 that are sequentially conveyed by a belt conveyor 8 or the like, in the apparatus according to the present invention, the ultrasonic generation time can be selected to be extremely short, for example, 1 to 3 milliseconds. Furthermore, since the time period for which the modulated ultrasonic waves are generated by the test container is very short, for example, within a few milliseconds, the containers 4 that are sequentially conveyed by the belt conveyor 8 etc. are automatically It is also easy to test, ie to test at high speed.

As described above, according to the apparatus according to the present invention, pulsed ultrasonic waves are projected onto a specimen material for a very short period of time, and the ultrasound waves modulated by the specimen material and which last for a short period of time are received. This is converted into a corresponding electrical signal and the energy value is compared with the energy value corresponding to a non-defective product to determine whether the material being inspected is good or bad, so the judgment is accurate and reliable. This makes it possible to accurately and reliably inspect test materials that are rich in material and are transported at high speed.

Although the above description has been made with reference to an example in which the present invention is applied to determining the quality of a sealed container such as equipment, the present invention is not limited to determining the quality of a sealed container such as equipment; It is clear that it can be used to inspect containers, materials, etc. that have the same effect on sound waves as described above, and that many changes and modifications can be made without departing from the scope of the invention as described above. Probably.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of an example of the present invention, and FIG. 2 is a waveform diagram used to explain the present invention. In the figure, 1 is a transducer, 2 is an ultrasonic pulse generator, 3 is a bridge circuit, 31 is a circuit, 4 is a test material, 5 is an amplifier, 6 is a detection circuit, and 7 is a pass/fail. A determination circuit, 8 is a belt conveyor, and T1 and T2 are transformers, respectively.

Claims (1)

[Claims] 1. Projecting ultrasonic waves from an ultrasonic transducer onto a test container, receiving reflected ultrasound modulated by the natural vibration of the test container with the ultrasonic transducer, and converting it into an electrical signal, In a container inspection device that processes the electric signal in a detection circuit and a quality determination circuit to determine the quality of the container to be tested, the ultrasonic transducer is arranged at a distance from the container to be tested, and Supplying a pulse signal with a fixed time width from an ultrasonic pulse generator to a sonic transducer, converting the ultrasonic waves emitted from the ultrasonic transducer into ultrasonic pulses that last for an extremely short fixed period of time, and generating the ultrasonic waves. A container inspection device characterized in that a pulse is projected onto the test container from one side.