Ultrasonic inspection method, program, and ultrasonic inspection device

Abstract

To provide an ultrasonic inspection method that can improve the inspection accuracy as to whether a test object is good or bad by accurately obtaining an arrival time of ultrasonic waves.SOLUTION: An ultrasonic inspection method for receiving ultrasonic waves transmitted from an ultrasonic transmitting unit toward a test object by an ultrasonic receiving unit to inspect the quality of the test object based on a detection value of the ultrasonic waves received by the ultrasonic receiving unit, includes: measuring an arrival time of the ultrasonic waves in a path of the ultrasonic waves from the ultrasonic transmitting unit to the ultrasonic receiving unit when no test object is present in the path; and adjusting a time range of an ultrasonic waveform used for the detection value of the ultrasonic waves based on the arrival time.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an ultrasonic inspection method, a program, and an ultrasonic inspection device. [Background technology]

[0002] There is known an ultrasonic inspection device that has an ultrasonic transmission unit that transmits ultrasonic waves toward a test subject and an ultrasonic reception unit that receives the ultrasonic waves transmitted from the ultrasonic transmission unit, and that inspects the quality of the test subject based on the detection value of the ultrasonic waves received by the ultrasonic reception unit (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-015965 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-106030 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 describes an ultrasonic inspection device that inspects defects in an object passing between an ultrasonic transmitter and an ultrasonic receiver. Patent Document 1 also describes that defects in the object are inspected based on the detected value of ultrasonic waves that are transmitted from the ultrasonic transmitter, transmitted through the object, and received by the ultrasonic receiver.

[0005] In order to improve the accuracy of defect inspection in an ultrasonic inspection device such as that described in Patent Document 1, it is important to accurately input the arrival time of ultrasonic waves from the time they are transmitted from the ultrasonic transmitter until they are received by the ultrasonic receiver. In this regard, conventionally, a predetermined value calculated by a formula that applies predetermined conditions has been used as the arrival time of ultrasonic waves. However, it is known that the speed of sound, for example, depends on temperature, and using this predetermined value may result in an error in the arrival time when the temperature environment changes.

[0006] From this perspective, a technique has been proposed for determining the speed of sound using a temperature measured by a temperature sensor, as described in Patent Document 2. However, even when this technique is used, there is a risk that the speed of sound cannot be calculated accurately due to heat generated by the ultrasonic inspection device and its peripheral devices.

[0007] An object of one aspect of the present disclosure is to provide an ultrasonic inspection method that can improve the accuracy of inspecting whether a subject is good or bad by accurately determining the arrival time of ultrasonic waves. [Means for solving the problem]

[0008] (1) An ultrasound inspection method according to one aspect of the present disclosure is an ultrasound inspection method in which ultrasound transmitted from an ultrasound transmitting unit toward a test subject is received by an ultrasound receiving unit, and the quality of the test subject is inspected based on the detection value of the ultrasound received by the ultrasound receiving unit. When the test subject is not present on the path of the ultrasound from the ultrasound transmitting unit to the ultrasound receiving unit, the method measures the arrival time of the ultrasound on the path, and adjusts the time range of the ultrasound waveform used for the detection value of the ultrasound based on the arrival time.

[0009] (2) In the above (1), the measurement of the arrival time may be performed while the subject is being transported to a position where the subject will be subjected to ultrasonic examination.

[0010] (3) In the above (1) or (2), the measurement of the arrival time may be performed at an environmental temperature for testing the subject.

[0011] (4) In any one of (1) to (3) above, the measurement of the arrival time may be performed using ultrasonic waves intermittently transmitted from the ultrasonic wave transmitting unit.

[0012] (5) In any one of (1) to (4) above, the measurement of the arrival time may be performed using an ultrasonic trigger.

[0013] (6) A program according to another aspect of the present disclosure causes an ultrasonic inspection device to execute any one of the ultrasonic inspection methods (1) to (5) above.

[0014] (7) An ultrasonic inspection device according to another aspect of the present disclosure has an ultrasonic transmitting unit that transmits ultrasonic waves toward a test subject and an ultrasonic receiving unit that receives the ultrasonic waves, and inspects the quality of the test subject based on the detection value of the ultrasonic waves received by the ultrasonic receiving unit. The ultrasonic inspection device further includes a measuring unit that measures the arrival time of the ultrasonic waves on the path from the ultrasonic transmitting unit to the ultrasonic receiving unit when the test subject is not present on the path, and an adjusting unit that adjusts the time range of the ultrasonic waveform used for the detection value of the ultrasonic waves based on the arrival time.

[0015] In this disclosure, the term "ultrasound trigger" refers to an ultrasonic wave used to detect that a subject has reached a position for ultrasonic examination. This "ultrasound trigger" includes not only the ultrasonic wave actually used to detect the subject, but also a series of ultrasonic waves transmitted before and after the ultrasonic wave actually used to detect the subject. [Effects of the Invention]

[0016] An ultrasound inspection method according to one aspect of the present disclosure can improve the inspection accuracy of determining whether a subject is good or bad by accurately determining the arrival time of ultrasound. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a flow diagram illustrating an ultrasonic inspection method according to one embodiment of the present disclosure. [Figure 2] FIG. 2 is a schematic plan view showing an ultrasonic inspection device according to an embodiment of the present disclosure. [Figure 3] FIG. 3 is a schematic side view of the ultrasonic inspection device of FIG. [Figure 4] FIG. 4 is a block diagram showing the configuration of the control unit in the ultrasonic inspection apparatus of FIG. [Figure 5] FIG. 5 is a schematic plan view for explaining the measurement step in the ultrasonic inspection method of FIG. [Figure 6] FIG. 6 is a schematic plan view for explaining the measurement step in the ultrasonic inspection method of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Note that the drawings are schematic and may not correspond to actual dimensions, proportions, etc. In this disclosure, the terms "first" and "second" are used to distinguish the components to which they are attached, and do not limit the number, order, priority, etc.

[0019] <Ultrasound inspection method> In this ultrasonic inspection method, ultrasonic waves transmitted from an ultrasonic transmitter toward an object to be inspected are received by an ultrasonic receiver, and the quality of the object is inspected based on the detected value of the ultrasonic waves received by the ultrasonic receiver. As shown in Fig. 1, this ultrasonic inspection method measures the arrival time of the ultrasonic waves on the path from the ultrasonic transmitter to the ultrasonic receiver when the object is not present on the path (measurement step S3), and adjusts the time range of the ultrasonic waveform used for the detected value of the ultrasonic waves based on the arrival time (adjustment step S4).

[0020] This ultrasonic inspection method measures the actual arrival time of ultrasonic waves transmitted from the ultrasonic transmitter and received by the ultrasonic receiver, thereby enabling accurate determination of the ultrasonic arrival time even when local temperature differences exist. In other words, although the arrival time of ultrasonic waves may vary depending on factors such as temperature, humidity, and atmospheric pressure, this ultrasonic inspection method allows accurate determination of the arrival time taking these factors into account. Furthermore, this ultrasonic inspection method measures the arrival time of ultrasonic waves along the path when the object is not present along the path, thereby enabling accurate determination of the arrival time while suppressing the influence of diffracted waves that travel around the side of the object and reach the ultrasonic receiver. This ultrasonic inspection method adjusts the time range of the ultrasonic waveform used to detect the ultrasonic waves based on the arrival time, thereby improving the accuracy of inspection of the quality of the object.

[0021] As described above, the ultrasonic inspection method can improve the accuracy of inspecting the quality of the test object by including the measuring step S3 and the adjusting step S4, so the steps other than the measuring step S3 and the adjusting step S4 are not particularly limited. However, the ultrasonic inspection method typically inspects the quality of the test object based on the time range after adjustment in the adjusting step S4 (inspection step S5), as shown in FIG. 1. As an example, the ultrasonic inspection method may transport the test object to be inspected (transporting step S1) and transmit ultrasonic waves from the ultrasonic transmitter to the ultrasonic receiver (ultrasonic transmission step S2) in parallel with the transport of the test object, as shown in FIG. 1. In this case, the ultrasonic inspection method may perform the measuring step S3 in parallel with the transporting step S1 and the ultrasonic transmission step S2.

[0022] Before describing each step of the ultrasonic inspection method, an example of an ultrasonic inspection device capable of implementing the ultrasonic inspection method of FIG. 1 will be described with reference to FIGS. 2 to 4. FIG.

[0023] <Ultrasonic inspection equipment> The ultrasonic inspection device 1 itself is an embodiment of the present disclosure. As shown in Figures 2 and 3, the ultrasonic inspection device 1 has an ultrasonic transmitter 11 that transmits ultrasonic waves toward an object P, and an ultrasonic receiver 12 that receives the ultrasonic waves. The ultrasonic inspection device 1 inspects the quality of the object P based on the detection value of the ultrasonic waves received by the ultrasonic receiver 12. As shown in Figure 4, the ultrasonic inspection device 1 also has a measurement unit 23 that measures the arrival time of the ultrasonic waves on the ultrasonic path from the ultrasonic transmitter 11 to the ultrasonic receiver 12 when the object P is not present on the path, and an adjustment unit 24 that adjusts the time range of the ultrasonic waveform used for the detection value of the ultrasonic waves P based on the arrival time.

[0024] In the ultrasonic inspection device 1, the measurement unit 23 and the adjustment unit 24 are included in the control unit 13. In addition to the measurement unit 23 and the adjustment unit 24, the control unit 13 may also include a generation unit 21 that generates a signal for controlling the ultrasonic waves transmitted from the ultrasonic transmission unit 11, a detection unit 22 that converts the ultrasonic signals received by the ultrasonic reception unit 12 into digital detection signals, and an inspection unit 25 that inspects the quality of the subject P based on the digital detection signals converted by the detection unit 22. The ultrasonic inspection device 1 may also include a transport mechanism 14 that transports the subject P.

[0025] The ultrasonic inspection device 1 measures the actual arrival time of ultrasonic waves transmitted from the ultrasonic transmitter 11 and received by the ultrasonic receiver 12, and can therefore accurately determine the arrival time of the ultrasonic waves even when local temperature differences exist. Furthermore, the ultrasonic inspection device 1 measures the arrival time of the ultrasonic waves in the path when the object P is not present in the path, and can therefore determine an accurate arrival time that suppresses the influence of diffracted waves that travel around the side of the object P and reach the ultrasonic receiver 12. The ultrasonic inspection device 1 adjusts the time range of the ultrasonic waveform used for the detection value of the ultrasonic waves based on the arrival time, and can therefore improve the accuracy of inspection as to whether the object P is good or bad.

[0026] The ultrasonic inspection device 1 is configured to inspect the quality of the subject P by transmitting ultrasonic waves through the subject P. In other words, the ultrasonic inspection device 1 is a transmission-type inspection device that performs ultrasonic inspection with the subject P placed between an ultrasonic transmitter 11 and an ultrasonic receiver 12. As the ultrasonic inspection device 1 is a transmission-type inspection device, it can significantly improve the inspection accuracy of the subject P by accurately determining the arrival time of the ultrasonic waves.

[0027] (ultrasonic transmitter) The ultrasonic wave transmitting unit 11 includes a piezoelectric element (transmitting piezoelectric element). The ultrasonic wave transmitting unit 11 can transmit ultrasonic waves based on the vibration of the transmitting piezoelectric element. The ultrasonic wave transmitting unit 11 may include a plurality of transmitting piezoelectric elements. In this case, the plurality of transmitting piezoelectric elements may be arranged in an array. For example, the plurality of transmitting piezoelectric elements may be arranged so as to be aligned in the vertical direction (Z-axis direction in FIGS. 2 and 3), or so as to be aligned in the horizontal direction (X-axis direction in FIGS. 2 and 3), or so as to be aligned in a matrix in both the vertical and horizontal directions.

[0028] (ultrasonic receiver) The ultrasonic receiving unit 12 includes a piezoelectric element (receiving piezoelectric element). The ultrasonic receiving unit 12 can receive ultrasonic waves based on the vibration of the receiving piezoelectric element. The ultrasonic receiving unit 12 converts the ultrasonic waves received by the receiving piezoelectric element into an analog electrical signal. The ultrasonic receiving unit 12 may include multiple receiving piezoelectric elements. The transmitting piezoelectric elements included in the ultrasonic transmitting unit 11 and the receiving piezoelectric elements included in the ultrasonic receiving unit 12 may be arranged opposite each other with a space between them. In other words, the number of transmitting piezoelectric elements included in the ultrasonic transmitting unit 11 and the number of receiving piezoelectric elements included in the ultrasonic receiving unit 12 may be the same, and in this case, the transmitting piezoelectric elements and the receiving piezoelectric elements may be arranged so that each pair faces each other with a space between them.

[0029] In the ultrasonic inspection device 1, a passage for the subject P is formed between the ultrasonic transmitter 11 and the ultrasonic receiver 12. More specifically, as shown in FIGS. 2 and 3, the ultrasonic inspection device 1 has a first housing 2 and a second housing 3 that are spaced apart. The ultrasonic transmitter 11 is disposed in the first housing 2, and the ultrasonic receiver 12 is disposed in the second housing 3. The space between the first housing 2 and the second housing 3 is configured as the passage. The ultrasonic transmitter 11 and the ultrasonic receiver 12 are disposed to face the passage. The first housing 2 may have a window (not shown) that exposes the ultrasonic transmitter 11 to the passage. The second housing 3 may have a window (not shown) that exposes the ultrasonic receiver 12 to the passage.

[0030] The subject P is transported by the transport mechanism 14 so as to pass through the passage (in the positive direction of the X-axis in FIGS. 2 and 3). The subject P is transported at a constant speed by the transport mechanism 14, and as it passes through the passage, it transmits ultrasonic waves transmitted from the ultrasonic transmitter 11. The ultrasonic waves that have passed through the subject P are then received by the ultrasonic receiver 12 and converted into analog electrical signals.

[0031] [Subject] The subject P has an inspection part 101, which is a target part for ultrasonic inspection. The subject P is not particularly limited, but an example of the subject P is a container having a sealed portion as the inspection part 101. The container is not particularly limited, but an example of the container is a bag such as a pouch having a heat-sealed portion. The subject P is transported by the transport mechanism 14 at a constant speed in a direction perpendicular to the thickness direction, and passes through the passage. When the subject P is a pouch, the ultrasonic inspection device 1 may be used to inspect defects such as poor sealing of the heat-sealed portion.

[0032] When the subject P is a pouch, a high-temperature member such as a heat seal bar may affect the sound speed of the ultrasonic waves transmitted from the ultrasonic transmitter 11. Even in such a case, the ultrasonic inspection device 1 can calculate the arrival time of the ultrasonic waves taking into account the effect of temperature.

[0033] (Control unit) The control unit 13 may be a computer including a processor such as a CPU (Central Processing Unit) and a program memory that stores programs executed by the processor. The control unit 13 is realized, for example, by the processor executing a program stored in the program memory. The control unit 13 may be built into the first housing 2 or the second housing 3, or may be located separately from the first housing 2 and the second housing 3.

[0034] [Generation section] The generation unit 21 generates, for example, a burst signal as a signal for controlling the ultrasonic waves transmitted from the ultrasonic transmission unit 11. The generation unit 21 generates the burst signal according to the timing and intensity of the ultrasonic waves transmitted by the ultrasonic transmission unit 11. The generation unit 21 generates the burst signal intermittently. The time interval for generating the burst signal may be, for example, 1 microsecond or more and 1 second or less. The burst signal generated by the generation unit 21 is converted into a burst wave of a predetermined frequency and output to the ultrasonic transmission unit 11.

[0035] [Detection unit] The detection unit 22 receives the analog detection signal from the ultrasonic receiving unit 12, amplifies the signal, equalizes it, and converts it into a digital detection signal by analog-to-digital (AD) conversion. The detection signal contains information about the intensity of the ultrasonic waves. The digital detection signal converted by the detection unit 22 is sent to the measurement unit 23 or the inspection unit 25.

[0036] [Measurement section] The measuring unit 23 measures the arrival time of the ultrasonic waves along the path of the ultrasonic waves transmitted from the ultrasonic transmitter 11 to the ultrasonic receiver 12. The measuring unit 23 may measure the arrival time from the time difference between the time when the ultrasonic waves are received by the ultrasonic receiver 12 and the time when the ultrasonic waves are transmitted from the ultrasonic transmitter 11, or may measure the arrival time from the time difference between the time when the ultrasonic waves are received by the ultrasonic receiver 12 and the time when the burst signal is generated by the generator 21. It is preferable that the measuring unit 23 measures the arrival time of the ultrasonic waves that travel straight from the ultrasonic transmitter 11 and arrive at the ultrasonic receiver 12.

[0037] The measuring unit 23 may measure the arrival time using ultrasonic waves transmitted from the ultrasonic transmitter 11 and received by the ultrasonic receiver 12, and may measure the arrival time before the subject P is transported by the transport mechanism 14, for example. However, it is preferable that the measuring unit 23 measures the arrival time using ultrasonic waves transmitted intermittently from the ultrasonic transmitter 11.

[0038] Furthermore, it is preferable that the measurement unit 23 measures the arrival time while the subject P is being transported toward the position where the ultrasonic examination is performed (the space between the ultrasonic transmitter 11 and the ultrasonic receiver 12; hereinafter, also referred to as the "ultrasound examination position R"). That is, it is preferable that the measurement unit 23 measures the arrival time using ultrasonic waves that are not blocked by the subject P (do not pass through the subject P) among the ultrasonic waves intermittently transmitted from the ultrasonic transmitter 11 while the subject P is being transported by the transport mechanism 14. This configuration makes it possible to measure the arrival time of the subject P in the examination environment, and therefore to appropriately correct the arrival time in response to changes in the examination environment. As a result, it is possible to improve the accuracy of the examination of the subject P. Whether the ultrasonic waves are blocked by the subject P can be determined by whether the detection value of the ultrasonic waves has fallen below a certain threshold. Whether the detection value of the ultrasonic waves has fallen below a certain threshold can be determined, for example, by the examination unit 25. In the ultrasonic examination device 1, multiple subjects P may be transported sequentially to the ultrasonic examination position R at intervals. In this case, "when the subject is being transported toward the ultrasonic examination position" means when any one of the multiple subjects is being transported toward the ultrasonic examination position.

[0039] It is preferable that the measurement unit 23 measures the arrival time at the test environment temperature of the subject P. When the test environment temperature changes over time, the ultrasonic inspection device 1 is suitable for correcting the time range of the ultrasonic waveform used for the detected value of the ultrasonic wave based on the changed temperature. By measuring the arrival time at the test environment temperature of the subject P, the ultrasonic inspection device 1 can further improve the inspection accuracy of the subject P. In the present disclosure, "at the test environment temperature of the subject" means a temperature within ±3°C of the test environment temperature of the subject, preferably within ±2°C, and more preferably within ±1°C.

[0040] It is preferable that the measurement unit 23 measures the arrival time using an ultrasonic trigger. In the ultrasonic inspection device 1, the ultrasonic waves intermittently transmitted while the subject P is being transported are ultrasonic triggers. By measuring the arrival time using an ultrasonic trigger, the ultrasonic inspection device 1 can easily measure the arrival time during a normal inspection process.

[0041] [Adjustment section] The adjustment unit 24 adjusts the time range of the ultrasonic waveform used for the examination of the subject P based on the arrival time measured by the measurement unit 23. The adjustment unit 24 may adjust the time range of the ultrasonic waveform used for the examination of the subject P in microsecond units. The adjustment unit 24 may adjust the time window (a time width set to cut out a part of the ultrasonic waveform) of the ultrasonic waves used for the ultrasonic examination. In this case, the adjustment unit 24 may adjust the detection start time or detection end time of the examination ultrasonic waves, starting from the time of transmission of the ultrasonic waves transmitted from the ultrasonic transmission unit 11 or the time of generation of the burst signal generated by the generation unit 21. An example of the adjustment procedure performed by the adjustment unit 24 will be described in detail below.

[0042] In the ultrasonic inspection device 1, if the arrival time of the ultrasonic waves is earlier than the preset time window, the ultrasonic waveform will be shifted forward by that amount within the time window. In this case, ultrasonic waves that have bypassed the subject P and reached the ultrasonic receiving unit 12 are more likely to be used, reducing the accuracy of the inspection of the subject P. On the other hand, if the arrival time of the ultrasonic waves is later than the set time window, the ultrasonic waveform will be shifted back by that amount within the time window. In this case, the ultrasonic waveform will not be included in part of the first half of the time window, making it more susceptible to the influence of noise and reducing the accuracy of the inspection of the subject P. In response to this, by appropriately adjusting the time window using the adjustment unit 24, it is possible to use ultrasonic waves of a desired waveform for the inspection of the subject P while suppressing the use of ultrasonic waves that have bypassed the subject P.

[0043] In addition, when the ultrasonic transmitting unit 11 and the ultrasonic receiving unit 12 each have multiple piezoelectric elements, the ultrasonic inspection device 1 may adjust the time range of the ultrasonic waveform for all pairs of piezoelectric elements at once, or may adjust the time range of the ultrasonic waveform for one pair or multiple pairs of piezoelectric elements.

[0044] [Inspection Department] The inspection unit 25 inspects the quality of the subject P using ultrasonic waves that are transmitted from the ultrasonic transmission unit 11, pass through the subject P, and are received by the ultrasonic reception unit 12. The inspection unit 25 inspects the quality of the subject P based on the detection values ​​of the ultrasonic waves received by the ultrasonic reception unit 12 within the time range adjusted by the adjustment unit 24. The inspection unit 25 may inspect the quality of the subject P based on the intensity of the ultrasonic waves received by the ultrasonic reception unit 12.

[0045] (Transport mechanism) The transport mechanism 14 has a holder 14a that holds the subject P. The transport mechanism 14 transports the subject P so that the inspection portion 101 of the subject P passes between the ultrasound transmitter 11 and the ultrasound receiver 12. The transport mechanism 14 may transport the subject P along the longitudinal direction of the inspection portion 101.

[0046] Next, each step in the ultrasonic inspection method of Fig. 1 will be described. Note that in this ultrasonic inspection method, the transporting step S1, ultrasonic wave transmitting step S2, measuring step S3, adjusting step S4, and inspection step S5 can be performed in parallel. For example, while transporting the subject P in the transporting step S1, the ultrasonic wave transmitting step S2, measuring step S3, and adjusting step S4 can be performed before the subject P reaches the ultrasonic inspection position R, and the inspection step S5 can be performed when the subject P reaches the ultrasonic inspection position R. Furthermore, in the transporting step S1, the subject P that has undergone ultrasonic inspection in the inspection step S5 can be transported so as to be discharged from the ultrasonic inspection position R.

[0047] (Transportation process) The transporting step S1 is performed by the transport mechanism 14. In the transporting step S1, the subject P is transported toward the ultrasonic inspection position R while being held by the holding unit 14a. In the transporting step S1, the subject P is transported at a constant speed so as to pass through the ultrasonic inspection position R. In the transporting step S1, it is preferable that the subject P does not stop between before reaching the ultrasonic inspection position R and before passing through the ultrasonic inspection position R. It is also preferable that the subject P does not accelerate or decelerate between before reaching the ultrasonic inspection position R and before passing through the ultrasonic inspection position R.

[0048] (ultrasonic transmission process) In the ultrasonic wave transmission step S2, when the subject P is not present in the ultrasonic wave path from the ultrasonic wave transmission unit 11 to the ultrasonic wave reception unit 12, ultrasonic waves are transmitted from the ultrasonic wave transmission unit 11 to the ultrasonic wave reception unit 12. The ultrasonic waves transmitted in the ultrasonic wave transmission step S2 are based on the burst signal generated by the generation unit 21. In the ultrasonic wave transmission step S2, it is preferable to transmit ultrasonic waves in a state where there is no obstacle present in the path that blocks the ultrasonic waves.

[0049] In the ultrasonic wave transmitting step S2, ultrasonic waves may be transmitted when the subject P is not present in the path, and the timing and number of times of transmission are not particularly limited. However, in the ultrasonic wave transmitting step S2, it is preferable to transmit ultrasonic waves intermittently.

[0050] (Measurement process) In the measurement step S3, the arrival time of the ultrasonic waves transmitted in the ultrasonic wave transmission step S2 is measured. The measurement step S3 is performed by the measurement unit 23. The measurement step S3 may be performed using the ultrasonic waves transmitted in the ultrasonic wave transmission step S2, and the timing and number of times of the measurement step S3 are not particularly limited. However, in the measurement step S3, it is preferable to measure the arrival time using ultrasonic waves transmitted intermittently from the ultrasonic wave transmission unit 11.

[0051] In the measurement step S3, it is preferable to measure the arrival time while the subject P is being transported toward the ultrasonic examination position R. With this configuration, it is possible to measure the arrival time under the examination environment of the subject P, and therefore it is possible to appropriately correct the arrival time for changes in the examination environment. As a result, it is possible to improve the accuracy of the examination of the subject P.

[0052] The measuring step S3 is preferably performed at the temperature of the examination environment of the subject P. According to this configuration, the accuracy of the examination of the subject P can be further improved.

[0053] As shown in FIG. 5 , in the measuring step S3, the measurement of the arrival time may be performed using the ultrasonic waves W immediately before the subject P reaches the ultrasonic inspection position R. More specifically, in this ultrasonic inspection method, while the subject P is transported in a transporting step S1, the ultrasonic waves W are intermittently transmitted in an ultrasonic transmission step S2. In this ultrasonic inspection method, the ultrasonic waves W transmitted in the ultrasonic transmission step S2 are intermittently received by the ultrasonic receiving unit 12. Here, as shown in FIG. 6 , if the subject P is present at the ultrasonic inspection position R, the ultrasonic waves W are blocked by the subject P. As a result, the intensity of the ultrasonic waves W received by the ultrasonic receiving unit 12 becomes lower than a certain threshold. In the measuring step S3, the arrival time may be measured by regarding the ultrasonic waves W immediately before the intensity of the ultrasonic waves W becomes lower than the threshold as the ultrasonic waves W immediately before the subject P reaches the ultrasonic inspection position R. In this ultrasonic inspection method, by measuring the arrival time using the ultrasonic waves W immediately before the subject P reaches the ultrasonic inspection position R, the accuracy of inspection of the subject P can be further improved.

[0054] In the measuring step S3, it is preferable that the measurement of the arrival time is performed using an ultrasonic trigger. In this ultrasonic inspection method, the ultrasonic waves intermittently transmitted in the ultrasonic transmission step S2 while the subject P is being transported in the transport step S1 are the ultrasonic trigger. In this ultrasonic inspection method, by measuring the arrival time using the ultrasonic trigger, the arrival time can be easily measured during a normal inspection process.

[0055] (adjustment process) In the adjustment step S4, the time range of the ultrasonic waveform used for the examination of the subject P is adjusted based on the arrival time measured in the measurement step S3. In the adjustment step S4, the time range of the ultrasonic waveform used for the examination of the subject P may be adjusted in microsecond units. In the adjustment step S4, the time window of the ultrasonic waves used for the ultrasonic examination may be adjusted. In this case, in the adjustment step S4, the detection start time or detection end time of the examination ultrasonic waves may be adjusted, starting from the time of transmission of the ultrasonic waves transmitted from the ultrasonic transmission unit 11 or the time of generation of the burst signal generated by the generation unit 21.

[0056] In addition, in the ultrasonic inspection method, when the ultrasonic transmitting unit 11 and the ultrasonic receiving unit 12 each have multiple piezoelectric elements, the measurement step S3 and the adjustment step S4 may be performed on all pairs of piezoelectric elements at once, or the measurement step S3 and the adjustment step S4 may be performed on one pair or multiple pairs of piezoelectric elements at a time.

[0057] (Inspection process) In the inspection step S5, the quality of the object P is inspected using ultrasonic waves that are transmitted from the ultrasonic transmission unit 11, pass through the object P, and are received by the ultrasonic reception unit 12. In the inspection step S5, the quality of the object P is inspected based on the detection values ​​of the ultrasonic waves received by the ultrasonic reception unit 12 in the time range adjusted in the adjustment step S4. In the inspection step S5, the quality of the object P may be inspected based on the intensity of the ultrasonic waves received by the ultrasonic reception unit 12.

[0058] <Program> A program according to an embodiment of the present disclosure causes an ultrasound inspection device to execute an ultrasound inspection method in which ultrasound transmitted from an ultrasound transmitter toward an object to be inspected is received by an ultrasound receiver, and the object is inspected for quality based on the detected value of the ultrasound received by the ultrasound receiver. The program causes the ultrasound inspection device to measure the arrival time of ultrasound along the path from the ultrasound transmitter to the ultrasound receiver when the object is not present along the path (measurement step), and adjust a time range of an ultrasound waveform used for the detected value of ultrasound based on the arrival time (adjustment step). The program may also cause the ultrasound inspection device to inspect the quality of the object based on the time range adjusted by the adjustment step (inspection step). The program may also cause the ultrasound inspection device to transport the object to be inspected (transportation step), and transmit ultrasound from the ultrasound transmitter to the ultrasound receiver in parallel with the transportation of the object to be inspected (ultrasound transmission step).

[0059] The program can be used to cause the ultrasonic inspection device 1 shown in Figures 2 to 4 to execute the ultrasonic inspection method shown in Figure 1. In this case, the transport step, ultrasonic wave transmission step, measurement step, adjustment step, and inspection step in the program can be the same as the corresponding steps in the ultrasonic inspection method described above. The program may be built into the ultrasonic inspection device 1 or may be located outside the ultrasonic inspection device 1.

[0060] As with the ultrasonic inspection method, the program can improve the inspection accuracy of determining whether the subject is good or bad by accurately determining the arrival time of ultrasonic waves.

[0061] [Other embodiments] The above-described embodiments do not limit the configuration of the present invention. Therefore, the above-described embodiments may include omissions, substitutions, or additions of components based on the description in this specification and common general technical knowledge, and all of these should be construed as falling within the scope of the present invention.

[0062] In the above embodiment, an example using a transmission-type ultrasonic inspection device has been described. However, the ultrasonic inspection device of the present disclosure may be a reflection-type ultrasonic inspection device. Furthermore, the ultrasonic inspection method and program of the present disclosure may also be performed using a reflection-type ultrasonic inspection device. The reflection-type ultrasonic inspection device reflects ultrasonic waves transmitted from an ultrasonic transmitter unit on an object to be inspected, and receives the reflected ultrasonic waves with an ultrasonic receiver unit. In this configuration, the measurement step temporarily places a reflector capable of reflecting ultrasonic waves in place of the object in the ultrasonic path, thereby measuring the arrival time of the ultrasonic waves along the path.

[0063] In the adjustment step, it is preferable to adjust the time range of the ultrasonic waveform used in inspecting the subject using the measurement value from the most recent measurement step. In the adjustment step, the time range may be adjusted based on the measurement value from the most recent measurement step, or based on multiple past measurement values. For example, in this ultrasonic inspection method, the measurement step may be performed every time the subject is inspected, at regular time intervals, or every time the device is operated. In this case, in the adjustment step, the time range may be adjusted based on the average value of the most recent n measurement values ​​(n may be any positive integer based on the inspection environment, etc., and may be a positive integer of 10 or less, for example). In addition, in the adjustment step, multiple past measurement values ​​that match the inspection environment, etc. may be extracted, and the time range may be adjusted based on the average value of these measurement values. [Explanation of symbols]

[0064] 1. Ultrasound inspection equipment 2. First enclosure 3 Second enclosure 11 Ultrasonic transmitter 12 Ultrasonic receiver 13 Control Unit 14 Transport mechanism 14a Holding part 21 Generation part 22 Detection unit 23 Measurement section 24 Adjustment section 25 Inspection Department 101 Part to be inspected P Subject R Ultrasound examination position W Ultrasound

Claims

1. An ultrasonic inspection method for inspecting a quality of an object by receiving ultrasonic waves transmitted from an ultrasonic transmitter toward the object with an ultrasonic receiver and inspecting the quality of the object based on a detection value of the ultrasonic waves received by the ultrasonic receiver, comprising: measuring the arrival time of the ultrasonic waves along a path from the ultrasonic transmitter to the ultrasonic receiver when the subject is not present along the path; The time range of the ultrasonic waveform used for the ultrasonic detection value is adjusted based on the arrival time. Ultrasound testing methods.

2. 2. The ultrasonic inspection method according to claim 1, wherein the measurement of the arrival time is performed while the subject is being transported toward a position where the subject will be ultrasonically inspected.

3. 2. The ultrasonic inspection method according to claim 1, wherein the measurement of the arrival time is performed at an inspection environment temperature of the subject.

4. 2. The ultrasonic inspection method according to claim 1, wherein the measurement of the arrival time is performed using ultrasonic waves intermittently transmitted from the ultrasonic transmission unit.

5. 5. The ultrasonic inspection method according to claim 1, wherein the measurement of the arrival time is performed using an ultrasonic trigger.

6. A program that causes an ultrasonic inspection device to execute the ultrasonic inspection method according to any one of claims 1 to 4.

7. An ultrasonic inspection device having an ultrasonic transmission unit that transmits ultrasonic waves toward an object to be inspected and an ultrasonic reception unit that receives the ultrasonic waves, and inspecting the quality of the object to be inspected based on a detection value of the ultrasonic waves received by the ultrasonic reception unit, a measuring unit that measures the arrival time of the ultrasonic waves on a path from the ultrasonic transmitter to the ultrasonic receiver when the subject is not present on the path; an adjustment unit that adjusts a time range of the ultrasonic waveform used for the detected value of the ultrasonic wave based on the arrival time; An ultrasonic inspection device comprising:

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