Particle transport velocity measuring device and particle transport velocity measuring method

Abstract

To provide a particle moving rate measuring device and a method for measuring the rate of a moving particle which can measure the rate of a moving particle without imaging.SOLUTION: The particle moving rate measuring device includes: an emission unit 1 for emitting a particle P; a collision unit 2 located separately from the emission unit 1, in which the light emission intensity when the particle P collides changes; and a detection unit 3 for detecting the intensity of emission. The particle moving rate measuring device acquires the rate of moving of the particle P on the basis of the distance between the emission unit 1 and the collision unit 2 and the length of time from when the emission unit 1 emits the particle P to when a change of the emission intensity is detected.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a particle movement speed measuring device and a particle movement speed measuring method.

Background Art

[0002] Patent Document 1 discloses a particle measuring device and the like. This particle measuring device includes an irradiation unit that irradiates a sheet-shaped laser beam, a scanning optical system that moves the irradiation position of the laser beam, a light receiving optical system and an imaging element, and an imaging unit that captures scattered light of the laser beam by particles. And a calculation unit that obtains the position and speed of the moving particles from the image captured by the imaging unit. As an example of the imaging unit, a high-speed camera is exemplified.

[0003] Patent Document 2 discloses a stress luminescent material powder and a resin composition. In Patent Document 2, a luminescent material that emits visible light near room temperature when a substance is stimulated from the outside is known. Among them, a material that emits light when receiving a mechanical stimulus of an externally applied force (compression, displacement, friction, impact, etc.) is described as a stress luminescent material. It is also described that a stress luminescent body can be manufactured by forming a composite material of a stress luminescent material powder and another inorganic material or organic material and then molding it. The stress luminescent body can be obtained, for example, by mixing or embedding a stress luminescent material powder in an organic material such as resin or plastic at an arbitrary ratio to form a composite material. It is said that when a mechanical external force is applied to this stress luminescent body, it emits light due to mechanical deformation.

Prior Art Documents

Patent Documents

[0004] <000…1>

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In conventional technology, as described in Patent Document 1, it was necessary to image the particles with a camera or similar device to obtain the particle's movement velocity. Therefore, in cases where it is difficult to image the particles with a camera, such as when the particle diameter of the target particles is small, when the color of the particles is difficult to distinguish from the background, or when the surrounding environment is unsuitable for imaging, it may not be possible to measure the particle's movement velocity. For this reason, there is a need for a particle movement velocity measuring device and a particle velocity measuring method that can measure the particle's movement velocity without imaging.

[0006] The present invention has been made in view of the above circumstances, and its purpose is to provide a particle velocity measuring device and a particle velocity measuring method that measure the velocity of particles without imaging. [Means for solving the problem]

[0007] The particle transport velocity measuring device according to the present invention, for achieving the above objective, A particle ejection unit, A collision section is spaced apart from the aforementioned injection section, and the light emission intensity changes when the particles collide with it. It comprises a detection unit for detecting the light emission intensity, The particle's movement speed is obtained based on the distance between the ejection unit and the collision unit, and the time elapsed from the time the particle is ejected from the ejection unit until the change in the luminescence intensity is detected.

[0008] The particle transport velocity measurement method according to the present invention, for achieving the above objective, The injection process involves ejecting particles from the injection unit, A collision step in which the particles collide with a collision section in which the light emission intensity changes when the particles collide, The process includes a detection step for detecting the light emission intensity, The particle's movement speed is obtained based on the distance between the ejection unit and the collision unit, and the time elapsed from the time the particle is ejected from the ejection unit until the change in the luminescence intensity is detected. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a particle velocity measuring device and a particle velocity measuring method that measure the particle's movement velocity without imaging. [Brief explanation of the drawing]

[0010] [Figure 1] This is a conceptual diagram illustrating the configuration of the particle transport velocity measuring device and the particle transport velocity measuring method according to this embodiment. [Figure 2] This figure illustrates the particle migration velocity measurement method according to this embodiment. [Figure 3] This is an example of a graph showing the relationship between the luminescence intensity at the impact point and the elapsed time. [Figure 4] This graph shows the relationship between luminescence intensity and elapsed time when 30 μm zirconia particles are ejected. [Figure 5] This graph shows the relationship between emission intensity and elapsed time when 15 μm zirconia particles are ejected. [Figure 6] This graph shows the migration speed of zirconia particles. [Figure 7] This diagram illustrates a method for measuring particle velocity using a high-speed camera. [Figure 8] These graphs show the injection time and background noise when the distance between the holding plate and the impact plate is measured at 1.9 mm. [Figure 9] This diagram illustrates an example of another procedure for calculating the velocity of a particle. [Modes for carrying out the invention]

[0011] Based on the drawings, a particle velocity measuring device and a particle velocity measuring method according to an embodiment of the present invention will be described.

[0012] FIG. 1 shows a conceptual diagram for explaining the configuration of a particle movement speed measurement apparatus (hereinafter referred to as the measurement apparatus 100) according to the present embodiment and a particle movement speed measurement method (hereinafter sometimes referred to as the measurement method) realized thereby. First, an overview of the measurement apparatus 100 and the measurement method realized thereby will be described.

[0013] The measurement apparatus 100 includes an ejection unit 1 that ejects particles P, a collision unit 2 that is separated from the ejection unit 1 and whose light emission intensity changes when the particles P collide, and a detection unit 3 that detects the light emission intensity.

[0014] In the measurement apparatus 100, the movement speed of the particles P is acquired based on the distance between the ejection unit 1 and the collision unit 2 and the time from when the particles P are ejected from the ejection unit 1 until a change in the light emission intensity is detected.

[0015] The measurement apparatus 100 includes an ejection process of ejecting the particles P from the ejection unit 1, a collision process of colliding the particles P with the collision unit 2 whose light emission intensity changes when the particles P collide, and a detection process of detecting the light emission intensity, and can realize a particle movement speed measurement method for acquiring the movement speed of the particles P based on the distance between the ejection unit 1 and the collision unit 2 and the time from when the particles P are ejected from the ejection unit 1 until a change in the light emission intensity is detected.

[0016] [[ID=~]]In the measurement apparatus 100 and the particle movement speed measurement method realized thereby, it is not necessary to image the particles or the trajectories of the particles in measuring the movement speed of the particles. That is, in the measurement apparatus 100 and the particle movement speed measurement method realized thereby, the movement speed of the particles can be measured without imaging.

[0017] Hereinafter, the measurement apparatus 100 and the measurement method will be described in detail.

[0018] As described above, the measuring device 100 according to this embodiment includes an ejection unit 1 for ejecting particles P, a collision unit 2 spaced apart from the ejection unit 1 and whose light emission intensity changes when particles P collide with it, and a detection unit 3 for detecting the light emission intensity. In addition, it further includes a selection plate 4 positioned between the ejection unit 1 and the collision unit 2, a light source 5 for emitting laser light, a control unit 8 for calculating the particle P movement speed, and a casing 9 for housing the ejection unit 1, the collision unit 2, and the selection plate 4.

[0019] In this embodiment, the injection unit 1, the impact unit 2, and the selection plate 4 are formed in a flat plate shape, as will be described later. For example, the injection unit 1, the impact unit 2, and the selection plate 4 are arranged in parallel in the order of injection unit 1, selection plate 4, and impact unit 2, with one side of the injection unit 1 facing one side of the impact unit 2 via the selection plate 4.

[0020] The injection unit 1 is formed in a flat plate shape and includes a flat plate-shaped retaining plate 10 (an example of a retaining unit) that holds particles, and a support unit 19 that supports the retaining plate 10 and is supported by the inner wall of the casing 9, and also supports the retaining plate 10.

[0021] The holding plate 10 has a support layer 11 made of a light-transmitting material and an energy-absorbing layer 12 that receives laser light and generates a shock wave.

[0022] The support layer 11 is a substrate that allows laser light to pass through and on which the energy absorption layer 12 is supported. The support layer 11 is formed in a flat plate shape. The support layer 11 is made of a light-transmitting material, such as quartz glass or sapphire. The thickness of the support layer 11 is not particularly limited. For example, the thickness of the support layer 11 is 500 μm or more and 2000 μm or less.

[0023] The energy absorption layer 12 is an energy conversion mechanism that generates kinetic energy to propel particle P upon reception of laser light. The energy absorption layer 12 is located on the surface of the support layer 11 facing the collision section 2. For example, the energy absorption layer 12 receives laser light, converts the energy supplied by the laser light into heat, and generates a shock wave by rapidly evaporating itself and rapidly expanding due to this heat. The energy absorption layer 12 ejects (propels) particle P with this shock wave. The energy absorption layer 12 can be formed by laminating it on the surface of the support layer 11, for example, by applying a viscous fluid containing graphite and oil to the surface of the support layer 11. The thickness of the energy absorption layer 12 is, for example, 5 μm to 200 μm.

[0024] The impact section 2 includes an impact plate 20 formed in the shape of a flat plate with its plate surface facing (parallel to that in this embodiment) the injection section 1, and a support section 29 supported by the wall of the casing 9 and supporting the impact plate 20.

[0025] The impact plate 20 has a shielding layer 21 positioned on the side facing the injection section 1, and a light-emitting section (hereinafter referred to as the light-emitting layer 22) positioned on the side opposite to the side facing the injection section 1 and formed in layers.

[0026] The light-emitting layer 22 includes a stress-emitting material or a stress-emitting body containing the same, whose light emission intensity changes (for example, increases) when a particle P collides with it. In this embodiment, the light-emitting layer 22 is formed of a stress-emitting body whose light emission intensity changes due to the stress caused by the strain generated in the light-emitting layer 22 when a particle P collides with it. The light-emitting layer 22 is, for example, a composite formed into a flat plate by kneading powder of a stress-emitting material whose light emission intensity changes into epoxy resin and dispersing it. The thickness of the light-emitting layer 22 is, for example, 50 μm or more and 1000 μm or less.

[0027] The stress-emitting element contained in the light-emitting layer 22 may store energy when irradiated with ultraviolet light and then emit the stored energy as light of a predetermined wavelength. The stress-emitting element may continue to emit light after being irradiated with ultraviolet light until it has consumed all of its stored energy, and it is sufficient that it temporarily increases or decreases its luminescence intensity when stimulated by stress caused by strain in the light-emitting layer 22. Below, we will explain with an example the case in which the luminescence intensity temporarily increases when the light-emitting layer 22 is stimulated by stress.

[0028] The shielding layer 21 is a thin, plate-like or thin-film layer that does not transmit light. The shielding layer 21 is formed on the surface of the light-emitting layer 22 facing the ejection unit 1. The shielding layer 21 blocks light that enters the light-emitting layer 22 from the side of the ejection unit 1.

[0029] The shielding layer 21 is, for example, a thin aluminum film such as aluminum foil. The thickness of the shielding layer 21 is, for example, 7 μm to 20 μm. The impact portion 2 can be formed, for example, by applying an uncured epoxy resin, which is made by kneading stress-luminescent material powder into epoxy resin, onto the shielding layer 21, which is a thin aluminum film.

[0030] The selection plate 4 is a flat plate-shaped member positioned between the injection section 1 and the impact section 2. The selection plate 4 has an opening 41 that penetrates its surface and has a support portion 49 supported by the inner wall of the casing 9. The opening 41 is formed to coincide with the perpendicular V drawn from the injection section 1 to the impact section 2, and the axis G passing through the center of the opening 41 is parallel to this perpendicular. In this embodiment, the perpendicular V drawn from the injection section 1 to the impact section 2 is parallel to the perpendicular drawn from the impact section 2 to the injection section 1.

[0031] The detection unit 3 is a sensor device that has a photomultiplier tube 30 that receives the light emitted from the collision unit 2 and detects the light emission intensity of the collision unit 2. The photomultiplier tube 30 is an optical sensor that achieves high sensitivity in detecting light by amplifying electrons emitted by the photoelectric effect.

[0032] The detection unit 3 is positioned on the opposite side of the collision unit 2 from the ejection unit 1. That is, the detection unit 3 detects the light emission intensity of the collision unit 2 from the opposite side of the collision unit 2 from the ejection unit 1. As described above, in the collision unit 2, the shielding layer 21 is formed on the surface of the light emission layer 22 facing the ejection unit 1, so the light directed from the ejection unit 1 towards the detection unit 3 via the collision unit 2 is shielded by the shielding layer 21. Therefore, only the light emitted from the light emission layer 22 enters the detection unit 3, and the incidence of other light that would cause disturbances is prevented. This improves the accuracy of the detection of the light emission intensity of the light emission layer 22 by the detection unit 3.

[0033] In this embodiment, the detection unit 3 receives the light emitted from the collision unit 2 with the photocathode 31 of the photomultiplier tube 30, amplifies the photoelectrons generated by this light reception, converts them into an electrical signal (pulse signal), and sends it to the control unit 8. The photomultiplier tube 30 is preferably arranged such that the photocathode 31 overlaps with the axis G and the photocathode 31 is parallel to the light-emitting layer 22.

[0034] In this embodiment, the detection unit 3 has the photocathode 31 of the photomultiplier tube 30 housed inside the casing 9. This prevents light from outside the casing 9 from disturbing the photomultiplier tube 30.

[0035] The light source 5 irradiates the energy absorption layer 12 with laser light L from the side of the support layer 11 in the holding plate 10. The light source 5 only needs to be capable of irradiating laser light L of a predetermined intensity for a predetermined time. For example, the light source 5 is an Nd-Yag laser light source capable of irradiating laser pulses as laser light L of a predetermined intensity and for a predetermined time. The light source 5 should be capable of outputting a pulse energy of 50 mJ or more as laser light L, and the pulse width should be adjustable in the range of 5 nm to 7 nm. The optical axis of the laser light L should be positioned to overlap with the axis G.

[0036] The control unit 8 is a functional unit that controls the operation of the light source 5 and calculates the movement speed of the particle P based on the operating status and detection results of the light source 5 and the detection unit 3. The control unit 8 may include a processor, a storage unit that stores a program to operate the processor, and a communication interface for communicating with the light source 5 and the detection unit 3. The processor may be a CPU (Central Processing Unit), MPU (Micro Processing Unit), GPU (Graphics Processing Unit), DSP (Digital Signal Processor), SoC (System on a Chip), etc., and may be composed of multiple processors of the same or different types. The processor controls the operation of the light source 5 and calculates the movement speed of the particle P by reading and executing a program from the storage unit. At least a part of these processes may be implemented in hardware.

[0037] The control unit 8 calculates the movement speed of the particle P based on the distance between the injection unit 1 and the impact unit 2, and the time elapsed from the time the particle P is ejected from the injection unit 1 until a change in light emission intensity is detected (an example of the calculation process). In this embodiment, the distance between the injection unit 1 and the impact unit 2 is the shortest distance between the two flat plates, the holding plate 10 and the impact plate 20.

[0038] In this embodiment, the control unit 8 calculates the movement velocity of the particle P based on the distance between the ejection unit 1 and the collision unit 2, the time from when the particle P is ejected from the ejection unit 1 until a change in emission intensity is detected, and the amount of change in emission intensity of the collision unit 2. The control unit 8 may detect the change in emission intensity of the collision unit 2 based on the amount of change in the number of photons detected (measured) by the photomultiplier tube 30.

[0039] The particle transport velocity is measured by the measuring device 100 as follows.

[0040] As shown in Figure 1, the particle P is attached to the surface of the holding plate 10 on the side facing the collision section 2 (in this embodiment, the surface of the energy absorption layer 12). The particle P is placed in the region of the holding plate 10 where the laser beam L is to be irradiated. In this embodiment, the region of the holding plate 10 where the laser beam L is to be irradiated is determined to be at a position that overlaps with the axis G. In Figure 1, due to the size of the drawing, only one particle P is drawn in the region where the laser beam L is to be irradiated, but it is preferable to place multiple particles P in this region.

[0041] With the particles P arranged on the holding plate 10, the control unit 8 activates the light source 5 and irradiates it with laser light L, generating a shock wave in the energy absorption layer 12 and ejecting the particles P towards the collision section 2. Multiple particles P may be ejected towards the collision section 2.

[0042] When a particle P collides with the collision unit 2 (in this embodiment, the shielding layer 21), the energy of this collision causes strain in the light-emitting layer 22. This strain temporarily increases the light emission intensity of the light-emitting layer 22 significantly. In other words, the light-emitting layer 22 emits light in response to the collision of particle P. The detection unit 3 detects the change in light emission intensity at this time (the light emission F generated in response to the collision of particle P). Note that the laser light L is shielded by the shielding layer 21 and does not interfere with the detection by the detection unit 3. The control unit 8 acquires the change in light emission intensity detected by the detection unit 3. In this embodiment, the control unit 8 receives the pulse signal sent from the detection unit 3 and acquires the change in light emission intensity.

[0043] The control unit 8 measures the elapsed time from the time the laser beam L is irradiated until the detection unit 3 detects a significant increase in the light emission intensity of the light-emitting layer 22. In this embodiment, the control unit 8 measures the elapsed time from the time the light source 5 is commanded to irradiate with the laser beam L until the number of pulse signals sent from the detection unit 3 increases significantly. Then, the distance between the ejection unit 1 and the collision unit 2 is divided by this elapsed time to calculate the movement velocity of the particle P ejected from the ejection unit 1.

[0044] When multiple particles P collide with the collision section 2, a large superimposed increase in the emission intensity of the light-emitting layer 22 occurs. In this case, the control unit 8 may consider the timing at which it first detects a large increase in the emission intensity of the light-emitting layer 22 as the timing at which the first particle P collided with the collision section 2. In this case, the control unit 8 measures the elapsed time from when the laser light L is irradiated until when the detection unit 3 first detects a large increase in the emission intensity of the light-emitting layer 22, and can calculate the speed of the fastest moving particle P based on this elapsed time and the distance between the ejection unit 1 and the collision section 2.

[0045] To more accurately measure the velocity of particle P, it is best to measure the velocity of particle P as it travels the shortest distance from the injection unit 1 to the impact unit 2. In other words, it is best to measure the velocity of particle P by having it collide with the impact unit 2 as it flies along a perpendicular line V (see Figure 2) drawn from the injection unit 1 to the impact unit 2. In this embodiment, particle P that has passed through the opening 41 of the selection plate 4 is made to collide with the impact unit 2. In other words, in this embodiment, particle P moving along a perpendicular line V drawn from the injection unit 1 to the impact unit 2 is selected and made to collide with the impact unit 2 (an example of the selection process). In this embodiment, it is possible to accurately measure the velocity of particle P. Note that particle P that deviates from the perpendicular line V will collide with the selection plate 4, thus preventing it from colliding with the impact unit 2.

[0046] Now, when a shock wave is generated in the energy absorption layer 12 by irradiating it with laser light L, fragments d of the energy absorption layer 12 may be ejected towards the impact area 2. One or more fragments d may be generated.

[0047] If fragments d are ejected towards the collision section 2, and the selection plate 4 is positioned between the ejection section 1 and the collision section 2, some of the fragments d will collide with the selection plate 4 and avoid colliding with the collision section 2.

[0048] Fragments d that have passed through the opening 41 may collide directly with the collision section 2. In this case, the collision of fragments d may cause a change (increase) in the light emission intensity at the collision section 2. That is, the light-emitting layer 22 emits light in response to the collision of fragments d. As a result, the change in light emission intensity at the collision section 2 due to the collision of fragments d and the change in light emission intensity at the collision section 2 due to the collision of particles P may occur superimposed within a predetermined period. In this case, the detection unit 3 detects both the change in light emission intensity due to the collision of fragments d and the change in light emission Fd due to the collision of fragments d. That is, the detection unit 3 detects both the light emission F generated in response to the collision of particles P and the light emission Fd generated in response to the collision of fragments d.

[0049] In this case, if the mass of particle P is sufficiently larger than the mass of fragment d (for example, more than twice as large), the control unit 8 may consider the timing at which it first detects a large increase in the luminescence intensity of the luminescence layer 22 as the timing at which particle P first collided with the collision unit 2. When the mass of particle P is sufficiently larger than the mass of fragment d, the degree of change (increase) in the luminescence intensity generated in the collision unit 2 due to the collision of fragment d is significantly smaller than the degree of change (increase) in the luminescence intensity in the collision unit 2 due to particle P colliding with the collision unit 2, so the two are distinguishable.

[0050] Since particle P has a significantly larger mass than fragment d, its velocity will be slower than that of fragment d. Therefore, after the laser beam L is shone on the energy absorption layer 12, fragment d will collide with the collision section 2 before particle P.

[0051] Furthermore, if the mass of particle P is sufficiently greater than the mass of fragment d, the strain when particle P collides with the collision section 2 will be sufficiently greater than the strain when fragment d collides with the collision section 2. Therefore, since the strain when particle P collides with the collision section 2 will be sufficiently greater than the strain when fragment d collides with the collision section 2, the increase in luminescence intensity will also be larger.

[0052] Furthermore, if there are a sufficiently large number of particles P colliding with the collision section 2, the fastest moving particle P will collide with the collision section 2, and then other particles P will continue to collide with the collision section 2.

[0053] In other words, the increase in luminescence intensity after the fastest moving particle P collides with the collision section 2 is predominantly due to the collision of particle P. Therefore, the control unit 8 may consider the timing at which it first detects a significant increase in the luminescence intensity of the luminescence layer 22, after a slight increase in the luminescence intensity of the luminescence layer 22, as the timing at which particle P first collides with the collision section 2.

[0054] The particle velocity measuring apparatus and particle velocity measuring method described above are useful for measuring particle velocity in technical fields where particle flight and movement are involved and it is necessary to evaluate the driving force of particles, such as cold spraying, shot peening, surface modification technology, and collision shielding. [Examples]

[0055] The migration speed of zirconia particles was measured using a measuring device with the configuration described above.

[0056] (Example 1) As zirconia particles, monodisperse zirconia particles with a particle size (diameter) of 30 μm and monodisperse zirconia particles with a particle size (diameter) of 15 μm were used.

[0057] The energy absorption layer of the injection molding section's holding plate was formed by creating a tape (thickness: 30 μm) composed of a black acrylic adhesive and transparent PET on the surface of a support layer (thickness: 1.3 mm) made of glass.

[0058] The zirconia particles described above were dispersed and attached to the surface of the energy absorption layer, and then a plate-shaped retaining plate was housed and fixed inside the casing. The amount of zirconia particles attached to the area where laser light irradiation was planned was approximately 500 particles / mm². 2 Approximately 1000 pieces / mm 2In this example, the distance between the retaining plate and the impact plate was 2.7 mm and 2.5 mm, respectively, when 30 μm zirconia particles were used and when 15 μm zirconia particles were used.

[0059] A light source capable of emitting an Nd-Yag laser (wavelength: 1064 nm) was used to emit the particles. The laser beam output was set to 50 mJ with a pulse width of 6 nm. The laser beam was focused and irradiated onto the surface of the energy absorption layer 12 so that its diameter was 400 μm.

[0060] The light-emitting layer of the impact plate in the collision section used a material in which stress-luminescent powder (manufactured by Sakai Chemical Industry Co., Ltd., product name: ML-200, lot number: Lot.OS108-2, europium-doped strontium aluminate powder) was kneaded and dispersed in epoxy resin. The concentration of stress-luminescent powder in the epoxy resin was 0.017 mg / 1 g. The emission wavelength of the light-emitting layer was 520 nm.

[0061] Aluminum foil (thickness: 10 μm) was used as the shielding layer for the impact plate.

[0062] When using 30 μm zirconia particles, the selection plate was placed 0.5 mm away from the holding plate. The thickness of the selection plate was 0.2 mm, and the opening diameter was 300 μm. When using 15 μm zirconia particles, the selection plate was also placed 0.5 mm away from the holding plate. The thickness of the selection plate was 0.2 mm, and the opening diameter was 300 μm.

[0063] Figure 3 shows an example of a graph illustrating the relationship between the luminescence intensity at the impact point and the elapsed time. In the graph in Figure 3, the luminescence intensity is shown on the vertical axis as the number of photons measured per unit time (10 ms) in the photomultiplier tube of the detection unit (measured photons), and the elapsed time is shown on the horizontal axis.

[0064] In the example shown in Figure 3, the measurement of the number of photons began after irradiating the light-emitting layer of the collision area with ultraviolet light until emission saturation occurred. As shown in Figure 3, the emission intensity of the light-emitting layer decreases over time. In the example in Figure 3, at time t (approximately 32 seconds), laser light is irradiated to collide a particle (in this example, the aforementioned 30 μm zirconia particle) with the collision area. Immediately after time t, an increase in the number of photons can be observed (see section Q in Figure 3).

[0065] Figure 4 shows a graph of the relationship between emission intensity and elapsed time when 30 μm zirconia particles are ejected by laser irradiation, with a solid line representing the relationship. In the graph in Figure 4, the elapsed time at the time of laser irradiation is set to 0 (s). Hereafter, this graph will be referred to as the emission graph. In the graph in Figure 4, the vertical axis represents the cumulative number of detected photons (integrated photon count) as emission intensity. The horizontal axis represents the elapsed time from the time of laser irradiation.

[0066] Furthermore, Figure 4 shows a dashed line graph illustrating the relationship between emission intensity and elapsed time when laser light is irradiated onto a portion of the holding plate where zirconia particles are not dispersed on the surface of the energy absorption layer. This graph corresponds to the background when 30 μm zirconia particles are ejected. Hereafter, this graph will be referred to as the background graph.

[0067] Figure 5 shows a graph of the relationship between emission intensity and elapsed time when 15 μm zirconia particles are ejected by laser irradiation, with a solid line representing the relationship. In the graph in Figure 5, the elapsed time at the time of laser irradiation is set to 0 (s). As with Figure 5, this graph will be referred to as the "emission graph" below. In the graph in Figure 5, the vertical axis represents the cumulative number of detected photons (integrated photon count) as emission intensity. In the graph in Figure 5, the horizontal axis represents the elapsed time from the time of laser irradiation.

[0068] Furthermore, Figure 5 shows a dashed line graph illustrating the relationship between emission intensity and elapsed time when laser light is irradiated onto a portion of the holding plate where zirconia particles are not dispersed on the surface of the energy absorption layer. This graph corresponds to the background when 15 μm zirconia particles are ejected. As with Figure 4, this graph will be referred to as the background graph below.

[0069] As shown in Figures 4 and 5, an increase in the number of integrated photons is observed in the background graph after irradiation with laser light. This is due to fragments of the energy absorption layer colliding with the impact plate.

[0070] As shown in Figures 4 and 5, a divergence point D is observed in the emission graph, where it deviates from the background graph. In other words, divergence point D is observed as the timing when the increase (change) in the number of integrated photons increases sharply (when a large increase in the emission intensity of the light-emitting layer is first detected).

[0071] Beyond this divergence point D, the number of integrated photons increases sharply, suggesting that the luminescence is predominantly caused by collisions between zirconia particles, rather than by the collision of fragments from the energy absorption layer with the impactor plate. In other words, the elapsed time (time) at which divergence point D is observed corresponds to the timing of the first collision between the zirconia particles and the impactor plate.

[0072] Therefore, in Figures 4 and 5, the elapsed time from when the laser beam was irradiated until the separation point D was observed is the travel time that the fastest moving zirconia particle spent moving the distance between the two plates, the holding plate and the impact plate. The distance between the two plates, the holding plate and the impact plate, is 2.7 mm when using 30 μm zirconia particles as shown in Figure 4, and 2.5 mm when using 15 μm zirconia particles as shown in Figure 5. In other words, by dividing the distance between the two plates, the holding plate 10 and the impact plate 20 (see Figure 1 for each), by the elapsed time from when the laser beam was irradiated until the separation point D was observed, the travel speed of the fastest moving zirconia particle can be calculated.

[0073] Figure 6 shows a bar graph comparing the migration speed of zirconia particles measured using the measurement device and measurement method according to this embodiment as described above, with the migration speed of zirconia particles measured by imaging with a high-speed camera as a reference example. In Figure 6, 30 μm zirconia particles are shown with the series name "30ZrO2", and 15 μm zirconia particles are shown with the series name "15ZrO2". In Figure 6, the black-filled bar graph shows the migration speed of zirconia particles measured by imaging with a high-speed camera (average value when measuring 6 particles for 30 μm zirconia particles and 2 particles for 15 μm zirconia particles). The hatched bar graph shows the migration speed of zirconia particles measured with the measurement device according to this embodiment (average value when measuring 3 particles). The high-speed camera imaging was performed with a resolution of 1280 × 512 at a frame rate of 110,000 frames / second. The magnification during imaging was set to 12.5x, and the width of one pixel in the captured image corresponded to 1.5 μm.

[0074] In measuring particle velocity using a high-speed camera, the particle emission method is the same as described above. The high-speed camera measurement shown for reference was performed by imaging the moving (flying) particles with the imaging device 6, which functions as a high-speed camera, as shown in Figure 7. The imaging device 6 captured images from a direction perpendicular to the direction of particle movement.

[0075] As shown in Figure 6, the results obtained by measurement using a high-speed camera and the results obtained by measurement using the measurement device and measurement method according to this embodiment are consistent. For example, when measuring 30 μm zirconia particles, both the measurement results using a high-speed camera and the results obtained by measurement using the measurement device and measurement method according to this embodiment show a particle velocity of approximately 400 m / s. From this result, it can be seen that the particle movement velocity can be accurately measured with the measurement device and measurement method according to this embodiment. In the case of zirconia particles as shown in this embodiment, measurement with a high-speed camera is still possible, but for example, when measuring particles with an even smaller particle diameter than the zirconia particles shown in this embodiment, when the color tone of the particles is difficult to distinguish from the background, or when the surrounding environment is not suitable for imaging, it is clear that measurement using the measurement device and measurement method according to this embodiment is advantageous compared to measurement with a high-speed camera.

[0076] (Example 2) In Example 2, unlike Example 1, the particle velocity was measured for 30 μm zirconia particles with a distance of 1.9 mm between the holding plate and the impact plate. Figure 8 shows, similar to Figure 4, the injection graph (solid line) and the background graph (dashed line) during measurement.

[0077] From Figure 8, the particle movement speed at a distance of 1.9 mm was calculated to be approximately 390 m / s. This measurement result is consistent with the particle movement speed (approximately 400 m / s) for the 30 μm zirconia particles shown in Example 1. Thus, the particle speed can be measured even when the distance between the holding plate and the impact plate changes. Note that the separation point D shown in Figure 8 has moved to an earlier point in time than the separation point D shown in Figure 4. This is because the distance between the holding plate and the impact plate is shorter in Example 2 (see Figure 8) compared to the case of the 30 μm zirconia particles in Example 1 (see Figure 4). In other words, the zirconia particles in Example 2 collided with the impact plate in a shorter time compared to the case of the 30 μm zirconia particles in Example 1.

[0078] As described above, a particle transport velocity measuring device and a particle transport velocity measuring method can be provided.

[0079] [Another embodiment] (1) In the above embodiment, when a deviation point D (see Figure 4, etc.) is observed in the graph during injection, the procedure for calculating (measuring) the speed of the fastest moving zirconia particle (an example of a particle) is calculated by dividing the distance between the two flat plates, the holding plate 10 and the impact plate 20 (see Figure 1 for each), by the elapsed time from when the laser light was irradiated until the deviation point D was observed. However, the procedure for calculating the speed of the fastest moving particle is not limited to the above procedure. The speed of the fastest moving particle can be calculated if the timing of the impact of the fastest moving particle on the impact section 2 can be identified.

[0080] Figure 9 shows the same emission graph as in Figure 4, as well as an example of another procedure for calculating the particle's velocity. In this graph, we can observe a section A where the number of integrated photons clearly increases in the elapsed time range from the moment the laser light L is irradiated (elapsed time 0(s) in the graph), and a section B after section A where the increase in the number of integrated photons is clearly greater than in section A. The divergence point D lies between section A and section B.

[0081] Therefore, first, define interval α in the middle of interval A. Interval α can be defined as approximately half the range of interval A. Note that interval α should not include the portion predicted to be the deviation point D.

[0082] Next, define interval β within interval B, in a portion close to interval A. Interval β should also be defined so as not to include the portion predicted to be the deviation point D. For example, the range of interval β can be set to be the same width as the range of interval α. The interval between interval α and interval β should be set to be approximately 50% to 100% of the width of the range of interval α.

[0083] Next, for each interval α and β, we draw graphs Lα and Lβ obtained by linear approximation (approximation by a linear function) using, for example, the least squares method.

[0084] Then, extrapolating graphs Lα and Lβ toward each other is performed to find the intersection point X. This intersection point X will be located at a position approximating the divergence point D. Similar to the case using the divergence point D, the velocity of the fastest moving particle can be calculated by dividing the distance between the two flat plates, the holding plate 10 and the impact plate 20 (see Figure 1 for each), by the elapsed time from when the laser beam was irradiated to the intersection point X.

[0085] In this embodiment, as an alternative method, the slope of the graph may be determined by differentiating the graph during ejection, and the particle's movement velocity may be calculated by identifying the point where this slope changes significantly. In the example of the graph during ejection shown in Figure 9, the point where the slope changes significantly for the second time after the laser light is irradiated corresponds to the intersection point X or the divergence point D.

[0086] (2) In the above embodiment, when the particles P are placed on the holding plate 10 and irradiated with laser light L, a shock wave is generated in the energy absorption layer 12 and the particles P are ejected toward the collision section 2. The procedure for calculating (measuring) the speed of the fastest moving zirconia particle (an example of a particle) is then explained by dividing the time elapsed from the time the laser light is irradiated until the separation point D is observed by the time elapsed.

[0087] However, in the measuring device and measuring method according to this embodiment, particle ejection is not limited to laser light or shock waves. Even if the particles are ejected by other methods, it is possible to calculate their movement speed if the timing of the start of measurement of the particle's movement time (in the example of the above embodiment, when the laser light L is irradiated) can be identified.

[0088] Furthermore, the configurations disclosed in the above embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with configurations disclosed in other embodiments, as long as no inconsistencies arise. Moreover, the embodiments disclosed herein are illustrative, and the embodiments of the present invention are not limited thereto, and can be modified as appropriate without departing from the object of the present invention. [Industrial applicability]

[0089] The present invention can be applied to a particle transport velocity measuring device and a particle transport velocity measuring method. [Explanation of Symbols]

[0090] 1: Injection part 10: Holding plate 100: Measuring device 11:Support layer 12: Energy absorption layer 19: Support part 2: Collision part 20: Collision plate 21: Shielding layer 22: Emitting layer 29: Support part 3: Detection unit 30: Photomultiplier tube 31: Photocathode 4: Selection board 41: Opening 49: Support part 5:Light source 6: Imaging device 8: Control Unit 9: Casing A: Section B: Section D: Divergence point F: Emission Fd: Light emission G: Axial center L: Laser light Lα: Graph Lβ: Graph P: Particle V: Perpendicular line X: Intersection d: debris t: time α: interval β: interval

Claims

1. A particle ejection unit, A collision section is spaced apart from the aforementioned injection section, and the light emission intensity changes when the particles collide with it. It comprises a detection unit for detecting the light emission intensity, A particle movement velocity measuring device that acquires the movement velocity of a particle based on the distance between the injection unit and the collision unit and the time from when the particle is ejected from the injection unit until a change in the luminescence intensity is detected.

2. The particle transport velocity measuring device according to claim 1, wherein the collision part has a light-emitting part that includes a stress-emitting element.

3. The aforementioned collision part is The plate is formed with the plate surface facing the injection section, A shielding layer is disposed on the side facing the injection section, The light-emitting portion is arranged on the side opposite to the side facing the injection portion and is formed in layers, The particle movement velocity measuring device according to claim 2, wherein the detection unit is arranged on the opposite side of the collision unit from the ejection unit.

4. The system further comprises a selection plate positioned between the injection unit and the collision unit, The aforementioned selection plate has an opening formed on its surface. The particle movement velocity measuring device according to claim 3, wherein the opening coincides with a perpendicular line drawn from the injection section to the impact section.

5. The control unit for calculating the aforementioned movement speed is further provided, The particle migration velocity measuring device according to claim 1, wherein the control unit calculates the migration velocity based on the amount of change in the luminescence intensity.

6. The detection unit has a photomultiplier tube that receives light emitted from the collision unit, The particle velocity measuring device according to claim 5, wherein the control unit calculates the velocity based on the change in the number of photons detected by the photomultiplier tube.

7. The control unit for calculating the aforementioned moving speed, and further comprising, The system further comprises a selection plate disposed between the injection unit and the collision unit, The aforementioned collision part is The plate is formed with the plate surface facing the injection section, A shielding layer is disposed on the side facing the injection section, It is positioned on the side opposite to the side facing the injection section and has a light-emitting layer containing a stress-emitting element, The detection unit has a photomultiplier tube that receives light emitted from the collision unit, The aforementioned selection plate has an opening formed on its surface. The opening coincides with the perpendicular line drawn from the injection section to the impact section, The particle transport velocity measuring device according to claim 1, wherein the control unit calculates the transport velocity based on the change in the number of photons detected by the photomultiplier tube.

8. The injection unit has a plate-shaped holding portion for holding the particles, The particle movement velocity measuring device according to claim 1, wherein the holding portion has an energy absorbing layer that receives laser light and generates a shock wave.

9. The energy absorption layer is further provided with a light source that irradiates it with laser light. The holding portion has a support layer made of a light-transmitting material, The energy absorption layer is arranged on the surface of the support layer facing the impact portion. The particle migration velocity measuring device according to claim 8, wherein the light source irradiates the energy absorption layer with laser light from the support layer side in the holding portion.

10. The injection process involves ejecting particles from the injection unit, A collision step in which the particles collide with a collision section in which the light emission intensity changes when the particles collide, The process includes a detection step for detecting the light emission intensity, A particle movement velocity measurement method for obtaining the particle's movement velocity based on the distance between the ejection unit and the collision unit and the time elapsed from the time the particle is ejected from the ejection unit until a change in the luminescence intensity is detected.

11. The particle migration velocity measurement method according to claim 10, wherein the collision portion has a light-emitting portion including a stress-emitting element.

12. The particle movement velocity measurement method according to claim 11, wherein, in the detection step, the light incident on the collision part from the side of the ejection part is shielded, and the light emission intensity is detected from the opposite side of the collision part from the ejection part.

13. The particle movement velocity measurement method according to claim 12, further comprising a selection step of selecting the particles moving along a perpendicular line to the collision portion drawn from the injection portion to the collision portion and causing them to collide with the collision portion.

14. The process further includes a calculation step for calculating the aforementioned moving speed, The calculation step is based on the amount of change in the luminescence intensity and the particle migration velocity measurement method according to claim 10.

15. In the detection step, the number of photons is measured using a photomultiplier tube that receives the light emitted from the collision section. The particle migration velocity measurement method according to claim 14, wherein the migration velocity is calculated based on the change in the number of photons in the calculation step.

16. A calculation step for calculating the aforementioned moving speed, The process further includes a selection step of selecting the particles moving along a perpendicular line from the injection unit to the collision unit and causing them to collide with the collision unit, In the detection step, while shielding the light incident on the collision part from the side of the ejection part, the light emitted from the collision part is received by a photomultiplier tube from the opposite side of the collision part from the ejection part, and the number of photons is measured. The particle migration velocity measurement method according to claim 10, wherein the migration velocity is calculated based on the change in the number of photons in the calculation step.

17. The particle movement velocity measurement method according to claim 10, wherein in the injection step, a laser beam is irradiated onto the energy absorption layer of the holding part that holds the particles to generate a shock wave, and the particles are ejected by the shock wave.

18. In the injection process The holding portion is placed on the surface of the support layer, which is made of a light-transmitting material, that faces the impact portion. The particle migration velocity measurement method according to claim 17, wherein the laser light is irradiated onto the energy absorption layer from the support layer side in the holding portion.

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