Fixtures and ultrasonic systems

Abstract

The present invention provides a jig and ultrasonic system that can efficiently apply ultrasonic waves to target equipment from the jig. [Solution] The jig 10 is connectable to the ultrasonic transducer 4 and applies ultrasonic waves to the piping 100. The jig 10 has a first protrusion 13 and a second protrusion 14, the first protrusion 13 being longer than the second protrusion 14. The first protrusion 13 is located in the area approximately in the center of the jig 10.

Description

Technical Field

[0001] The present disclosure relates to a jig that can be connected to an ultrasonic vibrator and applies ultrasonic waves to a target facility, and an ultrasonic system having the ultrasonic vibrator and the jig.

Background Art

[0002] In the pipes installed in a plant, scale damage occurs due to the deposition and adhesion of impurities contained in the liquid. In order to suppress such scale damage, various methods including cleaning treatment have been proposed. Patent Document 1 discloses a method for cleaning a device that holds a fluid, the device having a wall with an outer surface and an inner surface, a mechanical wave generation means, and a first end having at least one pair of protrusions adapted to function as a pair of point pressure sources, contacting at least one pair of protrusions with the outer surface, the mechanical wave generation means emitting a continuum of mechanical waves having a wave antinode substantially at the first end toward the inner surface through at least one pair of protrusions, the mechanical waves interfering on the inner surface and generating a vibrating inner surface, and the vibrating inner surface generating pressure pulses in the fluid.

[0003] Patent Document 2 discloses an ultrasonic cleaning device incorporating a characteristic detection device for an ultrasonic vibrator, which has a CPU with a built-in memory, a D / A converter that converts the digital output of the CPU into an analog signal, an oscillator that scans and transmits at a wide range of frequencies with the weak output of the D / A converter, an ultrasonic vibrator to which the output of the oscillator is applied via a voltage / current detection circuit, a small signal amplifier that detects and amplifies the minute voltage and current applied to the ultrasonic vibrator, and an A / D converter that converts the output of the small signal amplifier from an analog signal into a digital signal, and inputs the output of the small signal amplifier to the CPU to detect the frequency and impedance of the ultrasonic vibrator.

[0004] According to each of the above devices, it is said that ultrasonic vibration can be applied to the cleaning liquid between the object to be processed and the vibration transmission plate. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Special Publication No. 2022-519652 [Patent Document 2] Japanese Patent Publication No. 2009-106851 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] This disclosure aims to provide a jig and an ultrasonic system that can efficiently apply ultrasonic waves to target equipment from the jig. [Means for solving the problem]

[0007] A jig according to one aspect of the present disclosure is a jig that can be connected to an ultrasonic transducer and applies ultrasonic waves to a target device, the jig having a first protrusion and a second protrusion, the first protrusion being longer in length than the second protrusion, and the first protrusion being located in a region substantially in the center of the jig. [Effects of the Invention]

[0008] According to this disclosure, ultrasonic waves can be efficiently applied to the target equipment from a jig. [Brief explanation of the drawing]

[0009] [Figure 1] This is a conceptual diagram showing an ultrasonic system according to one embodiment of the present disclosure. [Figure 2] This is a conceptual diagram of the jig according to the first embodiment, viewed from the front. [Figure 3] This is a conceptual diagram showing the jig according to the first embodiment properly installed on the pipe, viewed from the axial direction of the pipe. [Figure 4]This graph shows the relationship between the phase difference and frequency of the ultrasonic waves applied to the ultrasonic transducer when the jig according to the first embodiment is properly installed on the piping. [Figure 5] This graph illustrates the phase difference of the current relative to the AC voltage of the ultrasound applied to the ultrasonic transducer of the ultrasonic system according to the first embodiment. [Figure 6] This is a conceptual diagram showing the jig according to the first embodiment installed at an angle to the pipe, viewed from the axial direction of the pipe. [Figure 7] This graph shows a first relationship between the phase difference and frequency of the ultrasonic waves applied to the ultrasonic transducer when the jig according to the first embodiment is installed at an angle to the piping. [Figure 8] This graph shows a second relationship between the phase difference and frequency of the ultrasonic waves applied to the ultrasonic transducer when the jig according to the first embodiment is installed at an angle to the piping. [Figure 9] This is a conceptual diagram, viewed from the axial direction of the pipe, showing the state in which the first protrusion of the jig according to the first embodiment has worn down and both the first and second protrusions are in contact with the pipe. [Figure 10] This graph shows the relationship between the phase difference and frequency of the ultrasonic waves applied to the ultrasonic transducer when the first protrusion of the jig according to the first embodiment is worn down and the first and second protrusions are in contact with the piping. [Figure 11] This is a conceptual diagram, viewed from the axial direction of the pipe, showing the state in which the first and second protrusions of the jig according to the first embodiment have worn down and the jig body has come into contact with the pipe. [Figure 12] This graph shows the relationship between the phase difference and frequency of the ultrasonic waves applied to the ultrasonic transducer when the first and second protrusions of the jig according to the first embodiment are worn down and the jig body is in contact with the piping. [Figure 13] This is a conceptual diagram of the jig relating to Comparative Example 1, viewed from the front. [Figure 14] This is a conceptual diagram showing the jig in Comparative Example 1 with multiple protrusions in contact with the pipe, viewed from the axial direction of the pipe. [Figure 15]It is a graph showing the relationship between the phase difference and frequency of ultrasonic waves applied to an ultrasonic vibrator in a state where a plurality of convex portions of the jig according to Comparative Example 1 are in contact with a pipe. [Figure 16] It is a conceptual diagram of the state where the second convex portion provided on the jig according to Comparative Example 2 is in contact with the pipe as viewed from the axial direction of the pipe. [Figure 17] It is a graph showing the relationship between the phase difference and frequency of ultrasonic waves applied to an ultrasonic vibrator in a state where the second convex portion provided on the jig according to Comparative Example 2 is in contact with the pipe. [Figure 18] It is a conceptual diagram of the jig of Modified Example 1 according to the first embodiment as viewed from the front. [Figure 19] It is a conceptual diagram of the jig of Modified Example 2 according to the first embodiment as viewed from the front. [Figure 20] It is a conceptual diagram of the jig of Modified Example 3 according to the first embodiment as viewed from the front. [Figure 21] It is a conceptual diagram of the jig according to the second embodiment as viewed from the front. [Figure 22] It is a conceptual diagram of the state where the jig according to the second embodiment is properly installed with respect to the pipe as viewed from the axial direction of the pipe. [Figure 23] It is a graph showing the relationship between the phase difference and frequency of ultrasonic waves applied to an ultrasonic vibrator in a state where the jig according to the second embodiment is properly installed with respect to the pipe. [Figure 24] It is a conceptual diagram of the state where the jig according to the second embodiment is installed obliquely with respect to the pipe as viewed from the axial direction of the pipe. [Figure 25] It is a graph showing the relationship between the phase difference and frequency of ultrasonic waves applied to an ultrasonic vibrator in a state where the jig according to the second embodiment is installed obliquely with respect to the pipe. [Figure 26] It is a conceptual diagram of the state where the first convex portion of the jig according to the second embodiment is worn and the first convex portion and the second convex portion are in contact with the pipe as viewed from the axial direction of the pipe. [Figure 27] It is a graph showing the relationship between the phase difference and frequency of ultrasonic waves applied to an ultrasonic vibrator in a state where the first convex portion of the jig according to the second embodiment is worn and the first convex portion and the second convex portion are in contact with the pipe. [Figure 28] This is a conceptual diagram of the jig of modified example 4 according to the second embodiment, viewed from the front. [Figure 29] This is a conceptual diagram showing the jig of modified example 4 according to the second embodiment in a state where it is properly installed on the pipe, viewed from the axial direction of the pipe. [Figure 30] This is a front view showing the jig of Embodiment 1 according to the first embodiment. [Figure 31] This is a front view showing the jig of Embodiment 2 according to the first embodiment. [Modes for carrying out the invention]

[0010] Hereinafter, a jig and an ultrasonic system according to one embodiment of this disclosure will be described with reference to Figures 1 to 22.

[0011] <Ultrasonic System> As shown in Figure 1, the ultrasonic system 1 cleans the inside of the target equipment 100 by applying ultrasonic waves to it. The ultrasonic system 1 prevents scale from adhering to the inside of the target equipment 100. Hereafter, the target equipment 100 will be described as "piping 100". The piping 100 may be a stainless steel pipe made of, for example, stainless steel. However, the piping 100 is not limited to a stainless steel pipe; it may be a steel pipe made of a material other than stainless steel. In other words, the piping 100 may be a steel pipe regardless of whether it is made of stainless steel or not. Furthermore, the piping 100 may be a metal pipe. The outer diameter of the piping 100 is, for example, in the range of 200 mm to 600 mm. However, the outer diameter may be less than 200 mm or greater than 600 mm. Furthermore, for example, the nominal diameter of the piping 100 may be between 200A and 500A.

[0012] Furthermore, the target equipment 100 may be a food plant. In addition, the target equipment 100 may be a paper mill. That is, the piping 100 may be part of a food plant or part of a paper mill. However, the target equipment 100 may be a plant other than these, or it may not be a plant at all. In the following, the axis of pipe 100 will be referred to as axis O.

[0013] The ultrasonic system 1 comprises an oscillation control device 2, an ultrasonic transducer (transducer) 4, a waveguide 8, and a jig (contact jig) 10. The oscillation control device 2 controls the ultrasonic transducer 4. The oscillation control device 2 controls the voltage and frequency applied to the ultrasonic transducer 4, thereby controlling the oscillation of the ultrasonic transducer 4. Part or all of the oscillation control device 2 is implemented, for example, by a personal computer or other information processing equipment.

[0014] The oscillation control device 2 comprises an oscillation unit (electrical waveform generation unit) 2a, a calculation unit 2b, a determination unit 2c, and a notification unit 2d. The oscillation unit 2a consists of, for example, a DDS (Digital Direct Synthesis Oscillator) and an amplifier, and is applied to the ultrasonic transducer 4 to cause the ultrasonic transducer 4 to oscillate. The calculation unit 2b calculates, for example, the AC voltage (voltage) and current applied to the ultrasonic transducer 4, the phase difference (between the voltage and current), and the resonant frequency. The calculation unit 2b also functions as a phase difference meter for calculating the phase difference. The determination unit 2c determines, for example, the presence or absence of a resonant frequency calculated by the calculation unit 2b, whether or not there is wear on the first protrusion 13 on the target equipment 100. The notification unit 2d notifies, for example, the phase difference (resonance frequency) calculated by the calculation unit 2b, and the malfunction status of the jig 10. The notification unit 2d notifies the operator of the aforementioned information, for example, by display or sound.

[0015] For example, all or part of the calculation unit 2b, the determination unit 2c, and the notification unit 2d are functional units (hereinafter referred to as software functional units) realized by a processor such as a CPU (Central Processing Unit) executing a program stored in the memory unit 150. Furthermore, for example, all or part of the calculation unit 2b, the determination unit 2c, and the notification unit 2d may be realized by hardware such as an LSI (Large Scale Integration), ASIC (Application Specific Integrated Circuit), or FPGA (Field-Programmable Gate Array), or by a combination of software functional units and hardware.

[0016] The ultrasonic transducer 4 consists of multiple piezoelectric elements 5 stacked and sandwiched between metal blocks 6. The ultrasonic transducer 4 can be realized, for example, by a known configuration. An AC voltage is applied to the ultrasonic transducer 4 (i.e., the stacked piezoelectric elements 5) from the oscillation control device 2 according to the frequency. A waveguide 8 is connected to the metal block 6. The waveguide 8 is made of, for example, a titanium alloy. A jig 10 is connected to the waveguide 8, for example, by a set screw (not shown). That is, the jig 10 is configured to be connectable to the ultrasonic transducer 4 via the waveguide 8.

[0017] In the ultrasonic system 1, the stacked piezoelectric material 5 is distorted by the AC voltage applied to the ultrasonic transducer 4 from the oscillation control device 2, and vibrations are emitted by the stacked piezoelectric material 5. The ultrasound (vibration) is transmitted to the jig 10 via the metal block 6 and the waveguide 8. The waveguide 8 is formed of, for example, a Ti alloy, which allows for efficient transmission of ultrasound to the jig 10. The jig 10 applies the transmitted ultrasonic waves to the liquid (fluid) inside the pipe 100 via the pipe 100. By applying ultrasonic waves to the liquid, the inside of the pipe 100 can be cleaned. In the following, the direction in which the ultrasonic waves (vibrations) generated by the jig 10 amplify is referred to as the excitation direction.

[0018] <Jig> As shown in Figures 2 and 3, the jig 10 has a jig body 12, a plurality of first protrusions 13, and a plurality of second protrusions 14. The jig body 12 has a front portion 12a and a back portion 12b. The difference in hatching density of the protrusions 13 and 14 in Figure 1 represents the difference between the protrusions 13 and 14.

[0019] The front portion 12a is positioned opposite the outer circumference 100a of the pipe 100. When the jig 10 is facing the pipe 100, the front portion 12a is formed in an arc shape along the outer circumference 100a of the pipe 100, as viewed from the direction of the axis O of the pipe 100. The front portion 12a has the shape of the side surface of a cylinder. The central axis of the cylinder is defined as axis O'. The arc formed by the front portion 12a is an arc with its center of curvature as axis O'. When the jig 10 is facing the pipe 100, axis O' is parallel to axis O. Hereinafter, in a plan view from the direction of axis O', the direction perpendicular to axis O' is called the radial direction, and the direction that circles around axis O' is called the circumferential direction.

[0020] The rear portion 12b is positioned on the opposite side of the front portion 12a from the outer circumference 100a of the pipe 100. The rear portion 12b is connected to the waveguide 8 (see Figure 1) by set screws (not shown), for example. Multiple first protrusions 13 and multiple second protrusions 14 are provided on the front surface 12a. First, the shape and arrangement of the first protrusion 13 and the second protrusion 14 of the jig in the first embodiment, as well as the relationship between the operating state of the jig and the resonant frequency, will be described.

[0021] <First protrusion> In the first embodiment shown in Figure 1, the first protrusion 13 of the jig is provided at a constant interval between a first position P1 and a second position P2 on the front surface 12a in the direction of axis O'. The first position P1 is located on the side of one end 12c of the front surface 12a in the direction of axis O'. The second position P2 is located on the side of the other end 12d of the front surface 12a in the direction of axis O'. Furthermore, the first protrusion 13 is provided at a constant interval between the third position P3 and the fourth position P4 of the front portion 12a in the circumferential direction. The third position P3 is located on the side of one end 12e of the front portion 12a in the circumferential direction. The fourth position P4 is located on the side of the other end 12f of the front portion 12a in the circumferential direction.

[0022] The multiple first protrusions 13 are provided on the front surface 12a in a fixed arrangement pattern approximately in the center with respect to the axis O' direction, and also in a fixed arrangement pattern approximately in the center with respect to the circumferential direction of the pipe 100. At least one of the multiple first protrusions 13 is provided in a region approximately in the center of the front surface 12a of the jig 10. Here, the region approximately in the center is, for example, a region that extends from the center point on the front surface 12a by a predetermined width in the axis O' direction and by a predetermined width in the circumferential direction, with respect to the center point on the front surface 12a. The center point is, for example, the center of the front surface 12a in the axis O' direction and the center of the front surface 12a in the circumferential direction. The region approximately in the center is, for example, a region that extends from the center point to positions 45% of the total length of the front surface 12a in the axis O' direction on both sides of the axis O' direction. The approximate center region is, for example, in the circumferential direction, the region extending from the center point to positions 45% of the total circumferential length of the front portion 12a on each side in the circumferential direction. However, if the total length in the axial direction O' and the total length in the circumferential direction of the front portion 12a are different, the approximate center region is the region extending from the center point to positions 45% of the longer of the total length in the axial direction O' and the total length in the circumferential direction, in both the axial direction O' and the circumferential direction. The first protrusion 13 is provided in at least such an approximate center region. However, not only the first protrusion 13 but also the second protrusion 14 may be provided in the approximate center region. The approximate center region may contain a mixture of the first protrusion 13 and the second protrusion 14. The approximate center region may, for example, be the region extending from the center point toward both sides in the circumferential direction to a point 30% away from the entire length of the axial O' direction of the front portion 12a or to a point 15% away from the center point.

[0023] Furthermore, the first protrusion 13 is formed with a length L1 that extends from the front surface 12a toward the outer circumference 100a of the pipe 100 to its tip. In the illustrated example, the first protrusion 13 protrudes from the front surface 12a in the vibration direction, and the length L1 of the first protrusion 13 is shown as the magnitude of the first protrusion 13 in the vibration direction. Here, if the first protrusion 13 protrudes radially from the front surface 12a, the length L1 of the first protrusion 13 may be the magnitude of the first protrusion 13 in the radial direction. In other words, the length L1 of the first protrusion 13 is the magnitude of the first protrusion 13 in the longitudinal direction (protrusion direction). The same applies to the length L2 of the second protrusion 14, which will be described later.

[0024] The radius of curvature formed by connecting the tips of the multiple first protrusions 13 is, for example, within a range of 5% greater than the radius of curvature of the pipe 100, for example, less than or equal to 105% of the radius of curvature of the pipe 100, and for example, between 100% and 105% of the radius of curvature of the pipe 100. Therefore, the tips of the multiple first protrusions 13 can be brought into contact with the outer circumference 100a of the pipe 100. This jig 10 is applicable to pipes 100 with an outer diameter in the range of 200 mm to 600 mm. Each jig 10 is formed to correspond to each pipe 100 with an outer diameter in the range of 200 mm to 600 mm. Multiple types of jigs 10 may be prepared, for example, depending on the size of the pipe 100. A jig 10 may be prepared for each pipe 100 with a different outer diameter, and may be attached to and detached from the waveguide 8, for example. With the jig 10 properly positioned on the outer circumference 100a of the pipe 100 (with the jig 10 facing the pipe 100), the tips of the multiple first protrusions 13 are properly in contact with the outer circumference 100a of the pipe 100.

[0025] In this way, the tips of the multiple first protrusions 13 contact the outer circumference 100a of the pipe 100. The contact surface between the multiple first protrusions 13 and the pipe 100 is formed in a curved shape when viewed from the direction of axis O'. The contact surface is formed by the tips of the multiple first protrusions 13. The shape (curved) of the contact surface when viewed from the direction of axis O' may be a curve centered on axis O'. The contact area of ​​the multiple first protrusions 13 is, for example, 0.5% to 40% of the cross-sectional area of ​​the jig 10 (surface area of ​​the front portion 12a). Preferably, the contact area of ​​the multiple first protrusions 13 is 0.5% to 5%. The contact area of ​​the multiple first protrusions 13 is, for example, the sum of the areas of the tips of the multiple first protrusions 13. The contact area of ​​the multiple first protrusions 13 may be less than 10% of the cross-sectional area of ​​the jig 10, or it may be more than 40%.

[0026] <Second protrusion> The second protrusion 14 is provided at a constant interval in the circumferential direction on the outside of the third position P3 and the outside of the fourth position P4 on the front surface 12a. The second protrusion 14 is also provided at a constant interval between the first position P1 and the second position P2 on the front surface 12a in the axial direction O'. The second protrusion 14 is formed to be short, with a length L2 extending from the front surface 12a toward the outer circumference 100a of the pipe 100. In other words, the length L1 of the first protrusion 13 is set to be longer than the length L2 of the second protrusion 14. Therefore, when the tips of the multiple first protrusions 13 are in contact with the outer circumference 100a of the pipe 100, the tips of the multiple second protrusions 14 can be positioned away from the outer circumference 100a of the pipe 100, radially outward from the pipe 100. In other words, the tips of the multiple second protrusions 14 can be positioned so that they do not come into contact with the outer circumference 100a of the pipe 100.

[0027] Further examples of the specific shapes of the first protrusion 13 and the second protrusion 14 will be described in detail in the embodiments shown in Figures 21 and 22. In these embodiments and each modified jig 10, the proportion of the first protrusion 13 to the total size of the first protrusion 13 and the second protrusion 14 may be larger in the circumferential center than in the circumferential ends. The circumferential center is, for example, the area between the third position P3 and the fourth position P4 in the circumferential direction. The circumferential ends are, for example, one side end 12e and the other side end 12f of the front portion 12a.

[0028] Here, the jig 10 is made of a material softer than the pipe 100 (e.g., metal). Specifically, the jig 10 is made of pure copper, copper alloy (e.g., brass), aluminum, aluminum alloy (e.g., duralumin), titanium, etc. The Vickers hardness (hardness) of pure copper and copper alloy (e.g., brass) is Hv50-120 and Hv80-150, respectively. The Vickers hardness of aluminum and aluminum alloy (e.g., duralumin (A2017)) is Hv20-40 and Hv130, respectively. The Vickers hardness of titanium is Hv155. Note that the material of the jig 10 is not limited to these.

[0029] On the other hand, the Vickers hardness of the stainless steel (SUS304) forming the pipe 100 is Hv200. In other words, the jig 10 is made of a material softer than the pipe 100. As a result, the first protrusion 13 on the jig 10 maintains good contact with the outer circumference 100a of the pipe 100. Note that the jig 10 is not limited to being made of a material softer than the pipe 100. In this embodiment, an example is described in which the entire jig 10 is formed from a material softer than the pipe 100, but the protrusions 13 and 14 may be made locally softer, for example, the first protrusion 13 and / or the second protrusion 14 may be formed from a material softer than the pipe 100.

[0030] The Vickers hardness of the jig 10 and the protrusions 13 and 14, as well as the Vickers hardness of the piping 100, can be measured, for example, by taking test pieces from the jig body 12 (jig 10) and the piping 100, and measuring them according to the test specified in JIS Z 2244:2009. If the first protrusion 13 and the second protrusion 14 are integrally formed from the same material as the jig body 12, for example, a test piece can be taken from the back surface 12b of the jig body 12 (jig 10), and the hardness of this test piece can be used as the hardness of the first protrusion 13 and the second protrusion 14. If the material of the jig 10 before processing is available, the test pieces may be obtained from the material of the jig 10 before processing.

[0031] <Relationship between the operating state of the jig and the resonant frequency> Figure 4 is a graph showing the relationship between the phase difference and frequency of the ultrasonic waves applied to the ultrasonic transducer when the jig is properly installed on the piping. In the graph in Figure 4, the vertical axis represents the phase difference (°), and the horizontal axis represents the ultrasonic frequency (kHz). G1 is a graph showing the relationship between the applied ultrasonic frequency and the phase difference.

[0032] As shown in Figures 1 and 4, for example, the resonant frequency of the ultrasonic transducer 4 itself is 20 kHz. Hereafter, the resonant frequency H1 of the ultrasonic transducer 4 itself may be referred to as the "reference frequency H1". Here, the ultrasonic transducer 4 is installed and used in the pipe 100. When the ultrasonic transducer 4 is installed in the pipe 100, the first protrusion 13 of the jig 10 comes into contact with the outer circumference 100a of the pipe 100. In this state, the resonant frequency (hereinafter also simply referred to as the resonant frequency) of the entire system, including the ultrasonic transducer 4, the pipe 100, and the fluid inside the pipe 100, changes (shifts) from the reference frequency H1 of 20 kHz. The change in the resonant frequency is influenced by the diameter and wall thickness of the pipe 100, the liquid flowing inside the pipe 100, etc. The resonant frequency (resonant state) is explained in Figure 5.

[0033] Figure 5 is a graph illustrating the phase difference of the current relative to the AC voltage of the ultrasound applied to the ultrasonic transducer. In the graph of Figure 5, the vertical axis represents voltage (V) and current (A), and the horizontal axis represents time (s). G2 is the voltage waveform showing the AC voltage of the ultrasound applied to the ultrasonic transducer 4. G3 is the current waveform generated by the applied voltage.

[0034] As shown in Figure 5, when the current waveform G3 is shifted relative to the AC voltage waveform G2, and there is a time difference between the voltage waveform G2 and the current waveform G3, the phase difference becomes θ. In this case, the ultrasound does not reach a resonant state. On the other hand, if the current waveform G3 overlaps with the voltage waveform G2 without being out of phase, the phase difference becomes 0. In this case, the ultrasound enters a resonant state. When the ultrasound is in a resonant state, the output of the ultrasound (voltage × current) increases, and the ultrasound is efficiently transmitted to the pipe 100.

[0035] (When installed normally) As shown in Figures 1, 3 to 5, the resonant frequency of the ultrasound when the ultrasonic transducer 4 is properly installed in the piping 100 changes from the resonant frequency of the ultrasonic transducer 4 itself. Therefore, it is necessary to find the resonant frequency (resonance point) when the ultrasonic transducer 4 is attached to the piping 100. That is, the frequency of the ultrasound emitted from the oscillation control device 2 is swept, an AC voltage is applied to the ultrasonic transducer 4, and the frequency H2 of the resonant state ultrasound is found when the phase difference between the voltage waveform G2 and the current waveform G3 is 0. In the illustrated example, the frequency H2 of the resonant state ultrasound where the phase difference between the voltage waveform G2 and the current waveform G3 is 0 (the phase difference in graph G1 is 0) is 22 kHz from graph G1. Hereafter, the frequency H2 of the resonant state ultrasound under normal conditions may be referred to as the "normal frequency H2".

[0036] The normal frequency H2 is calculated, for example, by the calculation unit 2b. That is, the normal frequency H2 can be defined as the frequency when the phase difference θ calculated by the calculation unit 2b is 0. However, in the graph G1 shown in Figure 4, there are two points where the phase difference θ is 0. (1) The point at which the phase difference becomes zero during the process in which the phase difference changes from a negative value to a positive value as the frequency increases. (2) The point at which the phase difference becomes zero in the process where the phase difference changes from a positive value to a negative value as the frequency increases. Of these, (1) is the frequency of the ultrasonic wave in the resonant state, and (2) is the frequency of the ultrasonic wave in the anti-resonant state. The calculation unit 2b (oscillation control device 2) can calculate the frequency of the ultrasonic wave in the resonant state (the frequency of the ultrasonic wave that is not in the anti-resonant state) as the resonant frequency when the phase difference is 0.

[0037] Here, when the jig 10 is properly installed on the pipe 100, the tips of the multiple first protrusions 13 are in contact with the outer circumference 100a of the pipe 100. In this case, the resonant frequency, which is the normal frequency H2, is close to the reference frequency H1. Therefore, the ultrasonic system 1 is operated by applying an AC voltage to the ultrasonic transducer 4 at the normal frequency H2. As a result, the ultrasonic system 1 can clean the inside of the pipe 100 by applying ultrasound from the jig 10 to the pipe 100. The oscillation control device 2 may also store these reference frequency H1 and normal frequency H2. For example, the operator can input the reference frequency H1 and normal frequency H2 to the oscillation control device 2 and have it store them.

[0038] (When installed at an angle) Next, the case where the jig 10 is installed at an angle relative to the pipe 100 will be explained based on Figures 6 to 8. As shown in Figure 6, the jig 10 may be installed at an angle to the pipe 100. In this state, the tips of the multiple first protrusions 13 contact the outer circumference 100a of the pipe 100, and the tips of the multiple second protrusions 14 also contact the outer circumference 100a of the pipe 100. This angled installation is undesirable, and it is desirable to change it to a normal installation state.

[0039] Figure 7 is a graph showing the first relationship between the phase difference and frequency of the ultrasonic waves applied to the ultrasonic transducer when the jig is installed at an angle to the piping. In the graph in Figure 7, the vertical axis represents the phase difference (°), and the horizontal axis represents the ultrasonic frequency (kHz). G4 is a graph showing the relationship between the applied ultrasonic frequency and the phase difference with a solid line. G5 is a graph showing the relationship between the applied ultrasonic frequency and the phase difference with a dashed line. Depending on the installation conditions, for example, graph G4 or graph G5 may be detected. Note that graphs G4 and G5 may each represent waveforms corresponding to the respective directions (for example, arrows C and D in Figure 6) decomposed with respect to the direction of the input vibration (for example, arrow B in Figure 6).

[0040] As shown in Figures 5, 6, and 7, when the jig 10 is installed at an angle to the piping 100, the resonant frequency H3 may be 27.5 kHz, as shown in G4. The resonant frequency H3 is the frequency of the ultrasonic wave in the resonant state where the phase difference between the current waveform G3 and the voltage waveform G2 is zero (the phase difference in graph G4 is zero), similar to the normal frequency H2 (see Figure 4). The resonant frequency H3 is significantly further away from the reference frequency H1 than the resonant frequency H2.

[0041] Furthermore, if the jig 10 is installed at an angle to the piping 100, two resonant frequencies H4 and H5 may appear, as in G5. The first resonant frequency H4 is 22 kHz. The second resonant frequency H5 is 24.5 kHz. Resonant frequencies H4 and H5 are ultrasonic frequencies in a resonant state where the phase difference of the current waveform G3 relative to the voltage waveform G2 is 0 (the phase difference in graph G5 is 0), similar to the normal frequency H2.

[0042] Figure 8 is a graph showing a second relationship between the phase difference and frequency of the ultrasonic waves applied to the ultrasonic transducer when the jig is installed at an angle to the piping. In the graph in Figure 8, the vertical axis represents the phase difference (°), and the horizontal axis represents the ultrasonic frequency (kHz). G6 is a graph showing the relationship between the applied ultrasonic frequency and the phase difference.

[0043] As shown in Figures 5, 6, and 8, when the jig 10 is installed at an angle to the piping 100, the resonant frequency H6 may be 24.2 kHz, as in G6. The resonant frequency H6, like the normal frequency H2, is the frequency of the ultrasonic wave in the resonant state where the phase difference of the current waveform G3 with respect to the voltage waveform G2 becomes 0 (the phase difference in graph G6 becomes 0). The resonant frequency H6 is significantly further away from the reference frequency H1 than the resonant frequency H2.

[0044] As described above, when the jig 10 is installed at an angle to the pipe 100, two resonant frequencies (H4, H5) may be detected, as in G5. Furthermore, even if only one resonant frequency is detected in this case, the detected resonant frequency is higher than the normal frequency H2. For example, the resonant frequency H3 at G4 is 27.5 kHz, and the resonant frequency H6 at G6 is 24.2 kHz.

[0045] (When worn) Next, the case in which the first protrusion 13 of the jig 10 wears down and the first protrusion 13 and the second protrusion 14 come into contact with the outer circumference 100a of the pipe 100 will be explained with reference to Figures 9 and 10. As shown in Figure 9, it is conceivable that the first protrusion 13 of the jig 10 will wear down, causing the first protrusion 13 and the second protrusion 14 to come into contact with the outer circumference 100a of the pipe 100.

[0046] Figure 10 is a graph showing the relationship between the phase difference and frequency of the ultrasonic waves applied to the ultrasonic transducer when the first protrusion of the jig is worn down and the first and second protrusions are in contact with the piping. In the graph in Figure 10, the vertical axis represents the phase difference (°), and the horizontal axis represents the ultrasonic frequency (kHz). G7 is a graph showing the relationship between the applied ultrasonic frequency and the phase difference.

[0047] As shown in Figures 9 and 10, when the first protrusion 13 of the jig 10 wears down and the first protrusion 13 and the second protrusion 14 come into contact with the outer circumference 100a of the pipe 100, the resonant frequency does not appear, as shown by G7. Note that in Figure 10, the upper limit of the horizontal axis is 34 kHz, and it is conceivable that the resonant frequency G7 may appear in the region above 34 kHz.

[0048] Next, the case in which the first protrusion 13 and the second protrusion 14 of the jig 10 wear away and disappear will be explained with reference to Figures 11 and 12. As shown in Figure 11, the first protrusion 13 and the second protrusion 14 (see Figure 3) of the jig 10 may wear down, causing the jig body 12 to come into contact with the outer circumference 100a of the pipe 100.

[0049] Figure 12 is a graph showing the relationship between the phase difference and frequency of the ultrasonic waves applied to the ultrasonic transducer when the first and second protrusions of the jig are worn down and the jig body is in contact with the piping. In the graph in Figure 12, the vertical axis represents the phase difference (°), and the horizontal axis represents the ultrasonic frequency (kHz). G8 is the phase difference curve.

[0050] As shown in Figures 5, 11, and 12, when the first protrusion 13 and the second protrusion 14 of the jig 10 wear down and the jig body 12 comes into contact with the outer circumference 100a of the pipe 100, the resonant frequency H7 becomes 31 kHz, as shown in G8. The resonant frequency H7 is the frequency of the ultrasonic wave in the resonant state where the phase difference of the current waveform G3 with respect to the voltage waveform G2 becomes 0 (the phase difference in graph G8 becomes 0), similar to the normal frequency H2. The resonant frequency H7 is even further away from the reference frequency H1 than when the jig is installed at an angle.

[0051] (Determination method using resonant frequency) Based on the above, the ultrasonic system 1 can be distinguished into normal installation, slanted installation, and wear as follows. In other words, when installed at an angle, (1) there are two resonant frequencies, or (2) there is only one resonant frequency, but it is higher than when installed normally. Furthermore, during wear, (1) the resonant frequency may not be detected, or (2) the resonant frequency may be detected, but it will be higher than when the unit is in normal condition.

[0052] Of the above methods of distinction, considering the case of (1) above when installed at an angle, and the cases of (1) and (2) above when worn, the determination unit 2c can determine, for example, that the jig 10 is installed at an angle to the pipe 100, or that the first protrusion 13 is worn (determined to be an abnormal condition), by taking into account the case of (1) above when installed at an angle, and the case of (1) and (2) above when worn. Specifically, if the resonance frequency appears to be shifted from the resonance frequency when installed at an angle (for example, normal frequency H2) calculated by the calculation unit 2b to within the range of a first predetermined threshold (for example, 24 kHz) and a second predetermined threshold (for example, 32 kHz), or if the resonance frequency does not appear within the range of the second predetermined threshold from the resonance frequency when installed at an angle (for example, normal frequency H2), the determination unit 2c determines that the jig 10 is installed at an angle to the pipe 100, or that the first protrusion 13 is worn (determined to be an abnormal condition).

[0053] The first predetermined threshold (e.g., 24 kHz) and the second predetermined threshold (e.g., 32 kHz) can be stored by the operator by inputting them into the oscillation control device 2. Alternatively, the oscillation control device 2 may calculate at least one of the first predetermined threshold and the second predetermined threshold from the normal frequency H2. The oscillation control device 2 may also include a storage unit for storing various information.

[0054] Next, Comparative Examples 1 and 2 of the embodiment will be described based on Figures 13 to 17. (Comparative Example 1) As shown in Figures 13 and 14, the jig 200 of Comparative Example 1 has multiple protrusions 202 across the entire front surface of the jig body 201. The multiple protrusions 202 are formed to have the same length extending from the front surface to the tip. Therefore, when the jig 200 is installed on the pipe 100, all of the multiple protrusions 202 make contact with the outer circumference 100a of the pipe 100. This Comparative Example 1 is not worn, but it is in a state similar to when the first protrusion 13 is worn.

[0055] Figure 15 is a graph showing the relationship between the phase difference and frequency of the ultrasonic waves applied to the ultrasonic transducer when all of the multiple protrusions on the jig of Comparative Example 1 are in contact with the piping. In the graph in Figure 15, the vertical axis represents the phase difference (°), and the horizontal axis represents the ultrasonic frequency (kHz). G9 is a graph showing the relationship between the applied ultrasonic frequency and the phase difference.

[0056] As shown in Figures 13 to 15, when the protrusion 202 provided on the jig 200 of Comparative Example 1 contacts the outer circumference 100a of the pipe 100, no resonant frequency appears in a predetermined frequency band (for example, the frequency band from the aforementioned reference frequency H1 to the second predetermined threshold), as in G9. However, it is conceivable that a resonant frequency may appear in the region above 34 kHz, for example.

[0057] (Comparative Example 2) As shown in Figure 16, the jig 210 of Comparative Example 2 has a plurality of first protrusions 212 and a plurality of second protrusions 213 on the front surface of the jig body 211. The plurality of first protrusions 212 are provided on the central side of the jig body 211. The plurality of second protrusions 213 are provided on the outside of the jig body 211. The length of the multiple second protrusions 213 from the front to the tip is set to be longer than that of the multiple first protrusions 212. Therefore, when the jig 210 is installed on the pipe 100, only the second protrusions 213 contact the outer circumference 100a of the pipe 100.

[0058] Figure 17 is a graph showing the relationship between the phase difference and frequency of the ultrasonic waves applied to the ultrasonic transducer when the second protrusion on the jig of Comparative Example 2 is in contact with the piping. In the graph in Figure 17, the vertical axis represents the phase difference (°), and the horizontal axis represents the ultrasonic frequency (kHz). G8 is a graph showing the relationship between the applied ultrasonic frequency and the phase difference.

[0059] As shown in Figures 5, 16, and 17, when the second protrusion 213 on the jig 210 of Comparative Example 2 contacts the outer circumference 100a of the pipe 100, the resonant frequency H8 becomes 27.5 kHz, as shown in G10. The resonant frequency H8 is the frequency of the ultrasonic wave in the resonant state where the phase difference of the current waveform G3 with respect to the voltage waveform G2 becomes 0 (the phase difference in graph G10 becomes 0), similar to the normal frequency H2. The resonant frequency H8 is a higher frequency than the normal frequency H2.

[0060] <Mechanism of action, effect> According to the jig 10 of the embodiment described above, as shown in Figures 1 to 3, the length L1 of the first protrusion 13 is made longer than the length L2 of the second protrusion 14. Furthermore, the first protrusion 13 is provided in a region approximately in the center of the jig 10. Therefore, the first protrusion 13 provided in the region approximately in the center of the jig 10 can be brought into contact with the outer circumference 100a of the pipe 100, while the second protrusion 14 can not be brought into contact with the outer circumference 100a of the pipe 100. This allows ultrasonic waves to be efficiently applied to the pipe 100 from the jig 10.

[0061] Furthermore, the contact area of ​​the first protrusion 13 was set to 0.5% to 40%, preferably 0.5% to 5%, of the cross-sectional area of ​​the jig 10. This allows ultrasonic waves to be efficiently applied to the piping 100 from the jig 10.

[0062] Furthermore, the first protrusion 13 and / or the second protrusion 14 are made softer than the pipe 100. This allows the first protrusion 13 to make good contact with the outer circumference 100a of the pipe 100. In addition, when ultrasonic waves are applied to the pipe 100 from the jig 10, wear and tear on the pipe 100 caused by the jig 10 can be suppressed.

[0063] In addition, the radius of curvature at the tip of the first protrusion 13 was set to be within a range 5% larger than the radius of curvature of the pipe 100. This allows the first protrusion 13, which is located in the area approximately in the center of the jig 10, to make good (reliable) contact with the outer circumference 100a of the pipe 100.

[0064] Here, for example, if the pipe 100 has a large diameter in the range of 200 mm to 600 mm, even if a protrusion of the same length is brought into contact with the pipe 100, it may not be possible to apply ultrasonic waves to the pipe 100. Therefore, the first protrusion 13 is brought into contact with the pipe 100 of the large diameter range of 200 mm to 600 mm. This allows ultrasonic waves to be efficiently applied to the pipe 100 from the jig 10.

[0065] Furthermore, according to the ultrasonic system 1 of the embodiment described above, as shown in Figures 1, 3, and 4, the determination unit 2c detects, for example, the presence or absence of a resonance frequency in a predetermined frequency band, and determines the wear of the first protrusion 13 based on the presence or absence of the resonance frequency. Specifically, for example, if the normal frequency H2 appears at a frequency close to the reference frequency H1, it is determined that only the first protrusion 13 is in normal contact with the outer circumference 100a of the pipe 100. In this state, the jig 10 is positioned toward the axis O of the pipe 100. This allows, for example, ultrasonic waves to be efficiently applied from the jig 10 toward the axis O of the pipe 100 as shown by arrow A.

[0066] Here, as shown in Figures 1, 9 to 12, if, for example, no resonant frequency appears in a first predetermined frequency band (for example, from the reference frequency H1 to a second predetermined threshold), it may be determined that the first protrusion 13 has worn down and that the first protrusion 13 and the second protrusion 14 are in contact with the outer circumference 100a of the pipe 100. Alternatively, it may be determined that the first protrusion 13 and the second protrusion 14 have worn down and that the jig body 12 is in contact with the outer circumference 100a of the pipe 100. At this point, the lifespan of the jig 10 can be determined. Therefore, the contact area of ​​the jig 10 with respect to the pipe 100 increases, and a decrease in contact pressure with respect to the outer circumference 100a of the pipe 100 can be prevented. This prevents the jig 10 (ultrasonic transducer 4) from shifting relative to the pipe 100 or falling off the pipe 100. Therefore, it prevents the pipe 100 from being damaged by the jig 10.

[0067] Furthermore, the determination unit 2c may determine wear of the first protrusion 13 based on the presence or absence of a resonant frequency, or, instead of determining wear of the first protrusion 13 based on the presence or absence of a resonant frequency, the determination unit 2c may determine the state of the jig 10 based on the resonant frequency calculated by the calculation unit 2b. For example, as shown in Figures 1, 6 to 8, in a second predetermined frequency band (for example, from the first predetermined threshold to the second predetermined threshold), resonant frequencies H3 and H6 appear that are significantly far from the reference frequency H1. In this case, it may be determined that the jig 10 is in a lateral displacement relative to its normal installation state and is in oblique contact with the axis O of the pipe 100. Alternatively, if two resonant frequencies H4 and H5 appear, it may also be determined that the jig 10 is in a lateral displacement and is in oblique contact with the axis O of the pipe 100. This prevents the jig 10 from sliding laterally relative to the pipe 100 due to vibration. Therefore, it is possible to prevent the jig 10 from damaging or wearing down the pipe 100.

[0068] Furthermore, because the jig 10 contacts the pipe 100 at an angle to its axis O, it is difficult to efficiently apply ultrasonic waves from the jig 10 to the pipe 100. Specifically, because the jig 10 contacts the pipe 100 at an angle to its axis O, the ultrasonic waves applied to the pipe 100 from the jig 10 (indicated by arrow B) are split into two directions: in the direction of the pipe 100's axis O (direction of arrow C) and in the circumferential direction (direction of arrow D). For this reason, it is difficult to efficiently apply the ultrasonic waves transmitted from the jig 10 to the axis O of the pipe 100.

[0069] Here, the determination unit 2c may determine that the operating state has changed if the resonant frequency changes by a predetermined value or more relative to the normal frequency H2 calculated by the calculation unit 2b, and may determine wear of the first protrusion 13. For example, wear of the first protrusion 13 can be determined if the resonant frequency becomes greater than a second predetermined threshold during operation of the ultrasonic system 1.

[0070] In other words, if the resonant frequency appears to be shifted from the normal frequency H2 calculated by the calculation unit 2b during normal installation to within the range of a first predetermined threshold and a second predetermined threshold, the determination unit 2c may determine that the jig 10 is tilted relative to the piping 100. Furthermore, as shown in Figures 9 and 10, if the resonant frequency does not appear within the range of the reference frequency H1 and a second predetermined threshold, it may be determined that the first protrusion 13 has worn down. Note that the resonant frequency may appear, for example, in a region exceeding the second predetermined threshold. Alternatively, as shown in Figures 11 and 12, if the resonant frequency is greater than the normal frequency H2 calculated by the calculation unit 2b during normal installation, and also exceeds a second predetermined threshold, it may be determined that the first protrusion 13 and the second protrusion 14 have worn down. In this way, the resonance frequency calculated by the calculation unit 2b allows for the determination of the installation and wear status of the jig 10, and it is possible to determine if it is not in a normal installation state (i.e., an abnormal state). This improves the reliability of the ultrasonic system 1.

[0071] As shown in Figures 1 to 3, the outer diameter of the piping 100 was set to a range of 200 mm to 600 mm. This allows the ultrasonic system 1 to be applied to large-diameter plants with piping in the range of 200 mm to 600 mm. This allows the ultrasonic system 1 to be applied to large-diameter piping 100 in food processing plants, paper mills, and the like.

[0072] Furthermore, the phase difference (resonance frequency) calculated by the calculation unit 2b is notified by the notification unit 2d. This allows for accurate confirmation of the phase difference (resonance frequency). Furthermore, the notification unit 2d can notify the user if the jig 10 is tilted relative to the pipe 100, or if the first protrusion 13 is worn down. This improves the quality of the ultrasonic system 1.

[0073] Next, a modified jig in the first embodiment will be described with reference to Figures 18 to 20. Note that in the modified jig, components identical or similar to those in the embodiment are denoted by the same reference numerals, and detailed explanations are omitted.

[0074] [Example 1] As shown in Figure 18, the jig 30 of the modified example 1 is modified in which, on the front surface 12a of the jig 10 of the embodiment, the first protrusions 13 arranged on one end 12c side are replaced with second protrusions 14, and the first protrusions 13 arranged on the other end 12d side are replaced with second protrusions 14. As a result, the multiple first protrusions 13 are arranged to form a square. According to the jig 30 of Modification 1, the same action and effect as the jig 10 of the embodiment can be obtained.

[0075] [Differentiation 2] As shown in Figure 19, in the modified example 2 of the jig 40, a plurality of first protrusions 13 and a plurality of second protrusions 14 are provided on the front portion 12a. The plurality of first protrusions 13 are arranged on the front portion 12a to form a square. One of the diagonals of the square of the plurality of first protrusions 13 is positioned along the axis O', and the other diagonal is positioned along the circumferential direction. According to the jig 40 of the modified example 2, the same action and effect as the jig 10 of the embodiment can be obtained.

[0076] [Difference 3] As shown in Figure 20, the jig 50 of the modified example 3 has a plurality of first protrusions 13 and a plurality of second protrusions 14 on its front surface 12a. The first protrusions 13 are arranged circumferentially at the center in the direction of axis O'. In addition, two first protrusions 13 are arranged circumferentially at one end 12c in the direction of axis O'. Furthermore, two first protrusions 13 are arranged circumferentially at the other end 12d in the direction of axis O'. According to the jig 50 of the modified example 3, the same action and effect as the jig 10 of the embodiment can be obtained.

[0077] Next, the shape and arrangement of the first protrusion 13 and the second protrusion 14 of the jig in the second embodiment, as well as the relationship between the operating state of the jig and the resonant frequency, will be explained with reference to Figures 21 to 27.

[0078] In the first embodiment, the first protrusion 13 of the jig was provided at a constant interval between the first position P1 and the second position P2 of the front surface 12a in the axial direction O'. In addition, the second protrusion 14 of the jig in the first embodiment was provided at a constant interval between the outside of the third position P3 and the outside of the fourth position P4 of the front surface 12a in the circumferential direction. The shape of the first protrusion 13 and the second protrusion 14 in the first embodiment is a rod shape with a square cross-section. On the other hand, in the jig of the second embodiment shown in Figure 21, the first protrusion 13 and the second protrusion 14 are provided, projecting continuously along the longitudinal direction of the pipe 100, extending from the first position P1 to the second position P2 of the front surface 12a.

[0079] In the second embodiment, there are two first protrusions 13 and three second protrusions 14. Specifically, as shown in Figure 21, in the second embodiment, there is one second protrusion 14 at a position (center) that divides the space between one side end 12e and the other side end 12f of the front portion 12a equally. Furthermore, with the central second protrusion 14 as the center, the first protrusions 13 and the second protrusions 14 are arranged symmetrically on both sides toward the side end 12e and the side end 12f, in this order and at equal intervals.

[0080] Other configurations of the second embodiment (length of the protrusion, radius of curvature when the tips of the multiple first protrusions 13 are connected, material, etc.) may be the same as those of the first embodiment, so they are omitted from this description.

[0081] Figure 23 is a graph showing the relationship between the phase difference and frequency of the ultrasonic waves applied to the ultrasonic transducer when the jig in the second embodiment is properly installed on the piping. In the graph of Figure 23, the vertical axis represents the phase difference (°), and the horizontal axis represents the ultrasonic frequency (kHz). G11 is a graph showing the relationship between the frequency and phase difference of the applied ultrasonic waves.

[0082] As shown in Figure 23, for example, the resonant frequency of the ultrasonic transducer 4 itself is 20 kHz.

[0083] (When installed normally) As shown in Figure 23, the ultrasonic resonance frequency when the ultrasonic transducer 4 is properly installed in the piping 100 changes relative to the resonance frequency of the ultrasonic transducer 4 itself. In the illustrated example, the ultrasonic frequency H2 of the resonant state where the phase difference of the current waveform G3 relative to the voltage waveform G2 is 0 (the phase difference in graph G1 is 0) is 21 kHz, as shown in graph G11.

[0084] Here, when the jig 10 is properly installed on the pipe 100, the tips of the multiple first protrusions 13 are in contact with the outer circumference 100a of the pipe 100. In this case, the resonant frequency, which is the normal frequency H2, is close to the reference frequency H1. Therefore, the ultrasonic system 1 is operated by applying an AC voltage to the ultrasonic transducer 4 at the normal frequency H2. As a result, the ultrasonic system 1 can clean the inside of the pipe 100 by applying ultrasound from the jig 10 to the pipe 100. The oscillation control device 2 may also store these reference frequency H1 and normal frequency H2. For example, the operator can input the reference frequency H1 and normal frequency H2 to the oscillation control device 2 and have it store them.

[0085] Next, the case in which the jig 10 of the second embodiment is installed at an angle relative to the pipe 100 will be explained with reference to Figures 24 and 25. As shown in Figure 24, the jig 10 may be installed at an angle to the pipe 100. In this state, the tips of the multiple first protrusions 13 contact the outer circumference 100a of the pipe 100, and the tips of the multiple second protrusions 14 also contact the outer circumference 100a of the pipe 100. This angled installation is undesirable, and it is desirable to change it to a normal installation state.

[0086] Figure 25 is a graph showing the first relationship between the phase difference and frequency of the ultrasonic waves applied to the ultrasonic transducer when the jig is installed at an angle to the piping. In the graph in Figure 25, the vertical axis represents the phase difference (°), and the horizontal axis represents the ultrasonic frequency (kHz). G12 is a graph showing the relationship between the applied ultrasonic frequency and the phase difference.

[0087] As shown in Figures 24 and 25, when the jig 10 of the second embodiment is installed at an angle to the pipe 100, the resonant frequency may not be detected, as in G12.

[0088] (When worn) Next, the case in which the first protrusion 13 of the jig 10 of the second embodiment wears down and the first protrusion 13 and the second protrusion 14 come into contact with the outer circumference 100a of the pipe 100 will be explained with reference to Figures 26 and 27. As shown in Figure 26, it is conceivable that the first protrusion 13 of the jig 10 wears down and the first protrusion 13 and the second protrusion 14 come into contact with the outer circumference 100a of the pipe 100.

[0089] Figure 27 is a graph showing the relationship between the phase difference and frequency of the ultrasonic waves applied to the ultrasonic transducer when the first protrusion of the jig 10 is worn down and the first and second protrusions are in contact with the piping. In the graph in Figure 27, the vertical axis represents the phase difference (°), and the horizontal axis represents the ultrasonic frequency (kHz). G13 is a graph showing the relationship between the applied ultrasonic frequency and the phase difference.

[0090] As shown in Figures 26 and 27, when the first protrusion 13 of the jig 10 wears down and the first protrusion 13 and the second protrusion 14 come into contact with the outer circumference 100a of the pipe 100, the resonant frequency does not appear, as shown by G13. Note that in Figure 27, the upper limit of the horizontal axis is 34 kHz, and it is conceivable that the resonant frequency G13 may appear in the region above 34 kHz. Regarding the case where the first protrusion 13 and the second protrusion 14 of the jig 10 in the second embodiment wear away and disappear, the situation is the same as with the jig in the first embodiment, so a description is omitted here.

[0091] (Determination method using resonant frequency) Based on the above, in the ultrasonic system 1 described above, the normal installation, skewed installation, and wear of the jig of the second embodiment can be distinguished as follows. In other words, when the device is installed at an angle, the resonant frequency is not detected. Furthermore, during wear, (1) the resonant frequency may not be detected, or (2) the resonant frequency may be detected, but it will be higher than when the unit is in normal condition.

[0092] Of the above methods of distinction, considering the case where no resonant frequency is detected when the fixture is installed at an angle, and the cases of (1) and (2) above when wear occurs, the determination unit 2c can determine, for example, that the fixture is installed at an angle or that wear occurs (an abnormal state that is not a normal installation) as follows. That is, if the resonant frequency appears shifted from the resonant frequency when the fixture is installed normally (for example, normal frequency H2) calculated by the calculation unit 2b to within the range of a first predetermined threshold (for example, 24 kHz) and a second predetermined threshold (for example, 32 kHz), or if the resonant frequency does not appear within the range of the resonant frequency when the fixture is installed normally (for example, normal frequency H2) to the second predetermined threshold, the determination unit 2c determines that the fixture 10 is installed at an angle to the pipe 100, or that the first protrusion 13 is worn (determined to be an abnormal state).

[0093] The first predetermined threshold (e.g., 24 kHz) and the second predetermined threshold (e.g., 32 kHz) can be stored by the operator by inputting them into the oscillation control device 2. Alternatively, the oscillation control device 2 may calculate at least one of the first predetermined threshold and the second predetermined threshold from the normal frequency H2. The oscillation control device 2 may also include a storage unit for storing various information.

[0094] Next, a modified jig 10 in the second embodiment will be described with reference to Figures 28 and 29.

[0095] [Differentiation Example 4] As shown in Figure 28, the jig 80 of the modified example 4 has two protrusions 81 in the circumferential direction. The protrusions 81 continuously project along the longitudinal direction of the pipe 100, spanning from a first position P1 to a second position P2 on the front surface 12a. As shown in Figure 29, the protrusions 81 have a semicircular cross-section when viewed from the pipe axis direction of the pipe 100. The two protrusions 81 are arranged symmetrically with respect to a point that bisects the distance between one end 12e and the other end 12f of the front surface 12a. The length L3 between the protrusions 81 in the circumferential direction is preferably 10 to 20 mm.

[0096] (Examples) Next, the jig in the first embodiment will be specifically described in Example 1 and Example 2. In the jigs of the examples, components that are the same or similar as those in the jig of the embodiment will be denoted by the same reference numerals, and detailed explanations will be omitted.

[0097] (Example 1) First, the jig 60 of Example 1 will be described based on Figure 30. As shown in Figure 30, the jig 60 of Embodiment 1 has a plurality of first protrusions 61 and a plurality of second protrusions 62 on the front surface 12a of the jig body 12. The first protrusions 61 correspond to the first protrusions 13 of the embodiment. The second protrusions 62 correspond to the second protrusions 14 of the embodiment. Multiple first protrusions 61 are provided inside the rectangular frame F1 on the front surface 12a. Multiple second protrusions 62 are provided outside the rectangular frame F1 on the front surface 12a. The rectangular frame F1 extends circumferentially on both sides, with respect to the circumferential center on the front surface 12a. The rectangular frame F1 extends along the entire length in the direction of axis O' on the front surface 12a.

[0098] The first protrusion 61 is formed in the shape of a regular square pyramid. The tip 61a of the first protrusion 61 is formed in the shape of a point. The tip 61a is a tiny square. Multiple first protrusions 61 are provided continuously in the axial direction O' and the circumferential direction. The second protrusion 62 is formed in the same square pyramidal shape as the first protrusion 61. The length of the first protrusion 61 is set to be longer than the length of the second protrusion 62.

[0099] Here, for example, the cross-sectional area of ​​the jig body 12 is 1117.829 mm². 2 The jig 60 has 214 first protrusions 61 and second protrusions 62, and 182 first protrusions 61.

[0100] In its initial state, when the first protrusion 61 is installed on the pipe 100 (see Figure 1), its tip 61a contacts the outer circumference 100a (see Figure 1) of the pipe 100. In this state, the contact size Lc1 (length of one side of a square, hereafter the same) of the tip 61a on the outer circumference 100a is 0.2 mm. The contact area of ​​the first protrusion 61 on the outer circumference 100a in its initial state is 7.28 mm². 2 The dimensions are (0.2 mm × 0.2 mm × 182 pieces). Therefore, the ratio of the contact area with the outer circumference 100a by the first protrusion 61 in the initial state is 0.6513% of the cross-sectional area of ​​the jig body 12.

[0101] On the other hand, the contact size Lc2 of the first protrusion 61 after wear is larger than the contact size Lc1 before wear, and is 1.5 mm. Also, the contact area with the outer circumference 100a in the worn state due to the first protrusion 61 is 409.5 mm². 2 The dimensions are (1.5 mm × 1.5 mm × 182 pieces). Therefore, the ratio of the contact area with the outer circumference 100a in the worn state due to the first protrusion 61 is 36.634% of the cross-sectional area of ​​the jig body 12.

[0102] (Example 2) Next, the jig 70 of Example 2 will be described with reference to Figure 31. As shown in Figure 31, the jig 70 of Embodiment 2 has a plurality of first protrusions 71 and a plurality of second protrusions 72 on the front surface 12a of the jig body 12. The first protrusions 71 correspond to the first protrusions 13 of the embodiment. The second protrusions 72 correspond to the second protrusions 14 of the embodiment. Multiple first protrusions 71 are provided inside the rectangular frame F2 on the front surface 12a. Multiple second protrusions 72 are provided outside the rectangular frame F2 on the front surface 12a. Like the rectangular frame F1, the rectangular frame F2 extends to both sides in the circumferential direction, with the circumferential center on the front surface 12a as the reference point. The rectangular frame F2 extends along the entire length in the direction of axis O' on the front surface 12a.

[0103] The first protrusion 71 is formed in the same shape as the first protrusion 61, in the shape of a regular square pyramid. However, the tip 71a of the first protrusion 71 is formed in the shape of a square prism with a square cross-section. In other words, the first protrusion 71 as a whole has the shape of a square prism extending from the vertex of a square pyramid. Multiple first protrusions 71 are provided continuously in the axial direction O' and the circumferential direction. The second protrusion 62 is formed in the same square pyramidal shape as the first protrusion 71. The length of the first protrusion 71 is set to be longer than the length of the second protrusion 72.

[0104] Here, for example, the cross-sectional area of ​​the jig body 12 is 1117.829 mm². 2 The jig 70 has 78 first protrusions 71 and 78 second protrusions 72, and 56 first protrusions 71.

[0105] In its initial state, when the first protrusion 71 is installed on the pipe 100 (see Figure 1), its tip 71a contacts the outer circumference 100a of the pipe 100 (see Figure 1). In this state, the contact size Lc3 between the tip 71a and the outer circumference 100a is 0.7 mm. The contact area between the first protrusion 71 and the outer circumference 100a in its initial state is 27.44 mm². 2 The dimensions are (0.7 mm × 0.7 mm × 56 pieces). Therefore, the ratio of the contact area with the outer circumference 100a by the first protrusion 71 in the initial state is 2.4548% of the cross-sectional area of ​​the jig body 12.

[0106] Furthermore, the contact size Lc4 of the first protrusion 71 after wear is 0.7 mm. Here, the tip 71a of the first protrusion 71 is formed in a rectangular prism shape. Therefore, the contact size Lc4 of the first protrusion 71 is the same as the contact size Lc3 of the first protrusion 71 before wear, which is 0.7 mm. Thus, the contact area with the outer circumference 100a in the worn state due to the first protrusion 61 is 27.44 mm². 2 The dimensions are (0.7 mm × 0.7 mm × 56 pieces). As a result, the ratio of the contact area with the outer circumference 100a in the worn state due to the first protrusion 71 is 2.4548% of the cross-sectional area of ​​the jig body 12, similar to the initial state.

[0107] Thus, the jig 70 of Example 2 can suppress the proportion of the contact area of ​​the first protrusion 71 in a worn state to be similar to that of the initial state. Therefore, the jig 70 of Example 2 can be used under more favorable conditions than the jig 60 of Example 1.

[0108] The technical scope of this disclosure is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of this disclosure.

[0109] For example, the notification unit 2d may not be necessary.

[0110] Furthermore, it is possible to replace the components in the first and second embodiments with well-known components as appropriate, without departing from the spirit of this disclosure.

[0111] (Note) Conventional ultrasonic cleaning devices have several drawbacks: the resonance point of the ultrasound deviates significantly from the resonance frequency of the transducer due to the size and wall thickness of the device (pipe) and the fluid inside the device, making it difficult to efficiently apply ultrasound to the liquid inside the device (pipe); and the vibration also occurs in the circumferential direction of the pipe, causing it to slip and damage the pipe. Furthermore, when applying ultrasound to the target equipment using an external transducer, if the contact area between the transducer and the contact jig on the outer surface of the equipment becomes large, the contact pressure decreases, which can cause the transducer to shift or fall off, damaging the target equipment.

[0112] <1> A jig according to one aspect of the present disclosure is a jig that can be connected to an ultrasonic transducer and applies ultrasonic waves to a target device, the jig having a first protrusion and a second protrusion, the first protrusion being longer in length than the second protrusion, and the first protrusion being located in a region substantially in the center of the jig.

[0113] In this embodiment, the length of the first protrusion is made longer than that of the second protrusion. Furthermore, the first protrusion is provided in a region approximately at the center of the jig. Therefore, the first protrusion, provided in the region approximately at the center of the jig, can be brought into contact with the target equipment, while the second protrusion can be prevented from coming into contact with the target equipment. This allows ultrasonic waves to be efficiently applied to the target equipment from the jig.

[0114] <2> the above <1> In the case of the jig, the contact area with the target equipment may be 0.5% to 40% of the cross-sectional area of ​​the jig.

[0115] According to this embodiment, by setting the contact area of ​​the first protrusion to 0.5% to 40%, preferably 0.5% to 5%, of the cross-sectional area of ​​the jig, ultrasonic waves can be efficiently applied from the jig to the target equipment.

[0116] <3> the above <1> or <2> In the jig relating to this, the first protrusion and / or the second protrusion may be softer than the target equipment.

[0117] In this embodiment, the first protrusion and / or the second protrusion are made softer than the target equipment. This allows the first protrusion to make good contact with the target equipment. Furthermore, when ultrasonic waves are applied to the target equipment from the jig, wear and tear on the target equipment caused by the jig can be suppressed.

[0118] <4> the above <1> from <3> In a jig according to any one of the embodiments, the radius of curvature to which the tip of the first protrusion is connected may be within a range from the radius of curvature of the target equipment to a range that is 5% greater than the radius of curvature of the target equipment.

[0119] According to this embodiment, by setting the radius of curvature to which the tip of the first protrusion is connected to be within a range 5% larger than the radius of curvature of the target equipment, the first protrusion provided in the area approximately at the center of the jig can be made to make good (reliable) contact with the target equipment.

[0120] <5> the above <1> from <4> In any one embodiment of the jig, the target equipment is a pipe, and the outer diameter of the pipe may be in the range of 200 mm to 600 mm.

[0121] For example, in the case of large-diameter pipes ranging from 200 mm to 600 mm, even if a protrusion of the same length was brought into contact with the pipe, it was sometimes impossible to apply ultrasonic waves to the pipe. Therefore, the first protrusion was made to come into contact with large-diameter pipes ranging from 200 mm to 600 mm. This allows ultrasonic waves to be efficiently applied to the pipe from the jig.

[0122] <6> An ultrasonic system according to one aspect of the present disclosure is an ultrasonic system having an ultrasonic transducer and a jig, wherein the jig is connectable to the ultrasonic transducer and applies ultrasonic waves to a target facility, and has a first protrusion and a second protrusion, the first protrusion being longer than the second protrusion, and the ultrasonic system comprises a calculation unit provided on the target facility and calculating the phase difference and resonant frequency of the voltage and current applied to the ultrasonic transducer to the target facility, and a determination unit that determines wear of the first protrusion based on the presence or absence of the resonant frequency calculated by the calculation unit.

[0123] According to this embodiment, the determination unit detects, for example, the presence or absence of a resonant frequency in a predetermined frequency band, and determines wear of the first protrusion based on the presence or absence of the resonant frequency. Specifically, for example, if resonance appears at a frequency close to the transducer resonant frequency, it is determined that only the first protrusion is in normal contact with the target equipment. In this state, the jig is positioned toward the center of the target equipment. This allows ultrasonic waves to be efficiently applied to the target equipment from the jig.

[0124] On the other hand, if, for example, no resonant frequency appears in a predetermined frequency band, it is determined that the first protrusion has worn down and both the first and second protrusions are in contact with the target equipment. Alternatively, it is determined that both the first and second protrusions have worn down and the jig body is in contact with the target equipment. At this point, the lifespan of the jig can be determined. Therefore, it is possible to prevent the contact area of ​​the jig with respect to the target equipment from increasing and the contact pressure with respect to the target equipment from decreasing. This prevents the vibrator from shifting relative to the target equipment or falling off the target equipment. Consequently, it is possible to prevent the target equipment from being damaged by the jig.

[0125] <7> An ultrasonic system according to one aspect of the present disclosure is an ultrasonic system having an ultrasonic transducer and a jig, wherein the jig is connectable to the ultrasonic transducer and applies ultrasonic waves to a target facility, and has a first protrusion and a second protrusion, the first protrusion being longer than the second protrusion, and the ultrasonic system comprises a calculation unit provided on the target facility and calculating the phase difference and resonant frequency of the voltage and current applied to the ultrasonic transducer to the target facility, and a determination unit that determines wear of the first protrusion on the target facility based on the resonant frequency calculated by the calculation unit.

[0126] In this embodiment, the determination unit detects the resonant frequency in a predetermined frequency band, for example, and determines wear of the first protrusion based on the resonant frequency. Specifically, for example, if resonance occurs at a frequency close to the resonant frequency of the transducer, it is determined that only the first protrusion is in normal contact with the target equipment. In this state, the jig is positioned toward the center of the target equipment. This allows ultrasonic waves to be efficiently applied to the target equipment from the jig.

[0127] On the other hand, if resonance occurs in a predetermined frequency band at a frequency far removed from the oscillator's resonant frequency, for example, it is determined that the jig has shifted laterally and is making oblique contact with the center of the target equipment. Alternatively, if two resonant frequencies occur, it is determined that the jig has shifted laterally and is making oblique contact with the center of the target equipment. This prevents the jig from sliding laterally relative to the target equipment. Therefore, it is possible to prevent the jig from damaging or wearing down the target equipment.

[0128] Furthermore, because the jig makes oblique contact with the center of the target equipment, it is difficult to efficiently apply ultrasonic waves from the jig to the target equipment.

[0129] <8> the above <7> In the ultrasonic system relating to the above, the determination unit may determine wear of the first protrusion if the resonant frequency changes by a predetermined value or more from the resonant frequency calculated by the calculation unit for normal installation.

[0130] According to this embodiment, the installation state and wear state of the jig can be determined by the resonant frequency calculated by the calculation unit. This improves the reliability of the ultrasonic system.

[0131] <9> the above <7> In the ultrasonic system relating to the above, the determination unit may determine that the jig is tilted relative to the target equipment or that the first protrusion is worn if the resonant frequency appears to be within the range of a first predetermined threshold and a second predetermined threshold from the resonant frequency calculated by the calculation unit for normal installation, or if the resonant frequency does not appear within the range of the second predetermined threshold from the resonant frequency for normal installation.

[0132] According to this embodiment, the installation state and wear state of the jig can be determined by the resonant frequency calculated by the calculation unit. This improves the reliability of the ultrasonic system.

[0133] <10> the above <6> from <9> In an ultrasonic system according to any one of the embodiments, the target equipment is a pipe, and the outer diameter of the pipe may be in the range of 200 mm to 600 mm.

[0134] According to this embodiment, the ultrasonic system can be applied to large-diameter piping in plants ranging from 200 mm to 600 mm. This makes it possible to apply the ultrasonic system to large-diameter piping in food processing plants, paper mills, and other similar plants.

[0135] <11> the above <6> or <10> An ultrasonic system according to any one of the embodiments may further include a notification unit that notifies the phase difference calculated by the calculation unit.

[0136] According to this embodiment, the phase difference (resonant frequency) calculated by the calculation unit is notified by the notification unit, allowing for accurate confirmation of the phase difference (resonant frequency).

[0137] <12> the above <11> In the ultrasonic system relating to this, the notification unit may notify that the jig has become skewed relative to the target equipment, or that the first protrusion has worn down.

[0138] According to this embodiment, the quality of the ultrasonic system can be improved by notifying the notification unit when the jig is tilted relative to the piping or when the first protrusion is worn down. [Explanation of Symbols]

[0139] 1... Ultrasonic system, 4... Ultrasonic transducer, 10, 30, 40, 50, 60, 70... Jig, 13, 61, 71... First protrusion, 14, 62, 72... Second protrusion, 61a, 71a... Tip of the first protrusion, 100... Piping (target equipment).

Claims

1. A jig that can be connected to an ultrasonic transducer and applies ultrasonic waves to the target equipment, The jig has a first protrusion and a second protrusion, The first protrusion is longer in length than the second protrusion. The first protrusion is located in the area approximately at the center of the jig. A jig characterized by the following features.

2. The contact area with the aforementioned equipment is 0.5% to 40% of the cross-sectional area of ​​the jig. The jig according to claim 1.

3. The first protrusion and / or the second protrusion are softer than the target equipment. The jig according to feature 1 or 2.

4. The radius of curvature at the point where the tips of the first protrusions are connected is within a range that is 5% greater than the radius of curvature of the target equipment. The jig according to feature 1 or 2.

5. The aforementioned equipment is piping, and the outer diameter of the piping is in the range of 200 mm to 600 mm. The jig according to feature 1 or 2.

6. An ultrasonic system having an ultrasonic transducer and a jig, The jig is connectable to the ultrasonic transducer and applies ultrasonic waves to the target equipment, and has a first protrusion and a second protrusion. The first protrusion is longer than the second protrusion. The aforementioned ultrasonic system, A calculation unit provided in the target equipment calculates the phase difference between the voltage and current applied to the ultrasonic transducer in the target equipment and the resonant frequency, The system includes a determination unit that determines wear of the first protrusion based on the presence or absence of a resonant frequency calculated by the calculation unit, An ultrasonic system characterized by the following features.

7. An ultrasonic system having an ultrasonic transducer and a jig, The jig is connectable to the ultrasonic transducer and applies ultrasonic waves to the target equipment, and has a first protrusion and a second protrusion. The first protrusion is longer than the second protrusion. The aforementioned ultrasonic system, A calculation unit provided in the target equipment calculates the phase difference between the voltage and current applied to the ultrasonic transducer in the target equipment and the resonant frequency, The system includes a determination unit that determines the wear of the first protrusion on the target equipment based on the resonant frequency calculated by the calculation unit, An ultrasonic system characterized by the following features.

8. The determination unit determines wear of the first protrusion if the resonant frequency changes by a predetermined value or more from the resonant frequency calculated by the calculation unit for normal installation. The ultrasonic system according to feature 7.

9. The determination unit determines that the jig is tilted relative to the target equipment, or that the first protrusion is worn, if the resonant frequency appears to deviate from the resonant frequency calculated by the calculation unit during normal installation within the range of a first predetermined threshold and a second predetermined threshold, or if the resonant frequency does not appear within the range of the resonant frequency during normal installation within the range of the second predetermined threshold. The ultrasonic system according to feature 7.

10. The ultrasonic system according to claim 7 or 8, characterized in that the target equipment is a pipe, and the outer diameter of the pipe is in the range of 200 mm to 600 mm.

11. A notification unit that notifies the phase difference calculated by the calculation unit, Furthermore, The ultrasonic system according to claim 7 or 8.

12. The notification unit notifies that the jig has become tilted relative to the target equipment, or that the first protrusion has worn down. The ultrasonic system according to feature 11.

Images