JP2022125440A - Vibration visualization device, apparatus diagnosing device using the same, method for visualizing vibration, and apparatus diagnosing method - Google Patents

Abstract

To provide a vibration visualization device that has a simple structure with a small number of components, is easily manufactured at low cost, and has a high vibration magnification and a high reliability.SOLUTION: The present invention relates to a vibration visualization device 10 for visualizing the vibration of an object. The device includes: a base part 11 installed on the object; a leaf spring 12 fixed to the base part 11 at one end 12d, another end 12e of which being a free end; a mirror 13 fixed to a first surface 12a1 of the leaf spring 12; and a laser light source 15 fixed to the base part 11, the laser light source sending a laser beam to the mirror 13. The leaf spring 12 has a natural vibration frequency Fc equal to a known vibration frequency Fv of the object.SELECTED DRAWING: Figure 1

Description

The present invention relates to a vibration visualization device, a device diagnosis device using the device, a vibration visualization method, and a device diagnosis method.

2. Description of the Related Art Conventionally, vibration sensors such as acceleration sensors, velocity sensors, and displacement sensors are used to diagnose failures of equipment such as rotating equipment, and vibrations of the equipment to be diagnosed are measured. Measurement is to convert and magnify the magnitude of a certain physical quantity into a physical quantity that can be recognized by humans, and to quantify and display it so that it can be read directly visually or numerically. In vibration measurement, specifically, vibration dynamic quantities such as vibration acceleration, vibration velocity, and vibration displacement detected by a vibration sensor are converted into electrical signals and subjected to amplification, AD conversion, filtering, scaling, averaging, and the like. signal processing is performed, and a numerical value representing the magnitude of vibration is displayed on the display unit (see, for example, Patent Document 1).

In addition, an acceleration sensor is attached to the target machine, and a diagnostic system that acquires the measurement data of vibration acceleration via a signal cable for diagnosis, and a wireless transmission device transmits the measurement data of vibration acceleration wirelessly and remotely There are also diagnostic systems that receive the measurement data for diagnosis, and vibrometers that serve as portable diagnostic devices.

The International Organization for Standardization (ISO) defines a method for judging the state of a rotating machine based on the vibration severity corresponding to the effective value of the vibration velocity of the rotating machine (ISO 10816-3 ). Vibrometers manufactured by many measuring instrument manufacturers are designed to evaluate the condition of rotating machinery based on this ISO criteria.

Japanese Patent Application Laid-Open No. 2003-302282

In a device diagnostic device using a conventional vibration meter as described in Patent Document 1, a piezoelectric element or a semiconductor acceleration sensor is installed in a target device to measure the vibration velocity of the target device, and the effective value of the vibration velocity is determined as the vibration severity. was used as a defining quantity to evaluate the condition of the target equipment. For example, the effective value of the vibration velocity is displayed on the display unit, and the state of the target device is determined based on the effective value of the vibration velocity as the vibration severity according to ISO 10816-3. For this reason, conventional device diagnostic devices generally include a processor (microcomputer) that receives and processes acceleration signals from an acceleration sensor, a peripheral device for the processing device, a power supply, a display device, and the like. It was also necessary to develop clothing.

In addition, in conventional vibrometers using semiconductor sensors, electronic circuits, processors, etc., such as those described in Patent Document 1, the magnification of microvibrations (microsignals) is limited to a certain extent due to the influence of noise and the like. was

In addition, in the device diagnosis method using a conventional vibration meter as described in Patent Document 1, when the target device is installed at a high place or in a dangerous place, a worker has to carry a portable vibration meter and access it safely. It was not easy to find and it was difficult to perform instrument diagnostics.

In addition, in the conventional device diagnosis method using a vibration meter as described in Patent Document 1, the operator must bring a portable vibration meter and press the vibration meter against the target device, and the measurement result changes depending on how it is pressed. , there was also a problem that the reliability of the device diagnosis was low.

In addition, conventional diagnostic systems that collect measurement data wirelessly or by wire for diagnosis are expensive and are not widely used.

The present invention has been made to solve such conventional problems, and has a simple structure consisting of a small number of parts, is easy to manufacture at a low manufacturing cost, and has a high vibration amplification rate and high reliability. An object of the present invention is to provide a vibration visualization device having a property, a device diagnosis device using the device, a vibration visualization method, and a device diagnosis method.

In order to solve the above problems, a vibration visualization device according to the present invention is a vibration visualization device (10) for visualizing vibration of an object (30), comprising: a base (11) installed on the object; a leaf spring (12) having one end fixed to the base portion and a free end at the other end; a mirror (13) fixed to a first surface of the leaf spring; a mirror (13) fixed to the base portion; a laser light source (15) for emitting laser light towards a mirror, wherein said leaf spring has a natural frequency (Fc) equal to the known vibrational frequency (Fv) of said object. Characterized by

As noted above, leaf springs have a natural frequency (Fc) equal to the known vibrational frequency (Fv) of the object. With this configuration, when the vibration of the object is transmitted to the leaf spring through the base portion installed on the object, the leaf spring vibrates (resonates) at the natural frequency in synchronization with the vibration of the object. Become. That is, the vibration of the object is magnified as the amplitude of the vibration of the resonating leaf spring (mechanical magnification).

A laser beam emitted from a laser light source is reflected by a mirror fixed to a resonating leaf spring, and output as a laser beam with an oscillating irradiation angle. A laser beam with an oscillating irradiation angle is irradiated onto, for example, a screen arranged outside the vibration visualization device, and can be displayed as a trajectory of a laser spot on the screen. That is, the laser beam with an oscillating irradiation angle generated by the vibration of the resonating leaf spring is enlarged as the trajectory of the laser spot projected on the screen placed at a certain distance from the vibration visualization device (optical expansion).

Thus, the present invention does not require electronic circuitry to perform signal processing, has a simple structure with a few parts, is easy to manufacture and inexpensive to manufacture, and provides mechanical and optical magnification due to resonance. As a result, minute vibrations can be reliably detected and visualized at a high magnification, enabling highly reliable equipment diagnosis.

Further, the vibration visualization device according to the present invention may further include a weight (14) attached to the second surface of the leaf spring in a position-adjustable manner for adjusting the natural frequency of the leaf spring. .

With this configuration, the vibration visualization device according to the present invention can easily cause the leaf spring to resonate with the vibration of the object by adjusting the position (height) of the weight on the second surface of the leaf spring. become.

Further, the vibration visualization device according to the present invention has a plate-like member (18) made of non-magnetic metal, and one surface portion (18a1) of the plate-like member is arranged at a constant distance (d) from the weight. The weight may further comprise a damper (180) having one end (18d) fixed to the base portion such that the weight includes a magnet (14).

With this configuration, in the vibration visualization device according to the present invention, the vibration of the leaf spring moves the magnet attached to the second surface of the leaf spring toward or away from the non-magnetic metal plate member of the damper. As a result, an eddy current is generated in the plate member of the damper. Vibrational energy is dissipated as heat energy due to ohmic loss caused by eddy currents, exhibiting a vibration damping effect. This suppresses vibration of the leaf spring. As a result, the half-value width of the leaf spring at the time of resonance is widened, and the leaf spring can resonate even if the known vibration frequency of the object deviates to some extent.

Further, in the vibration visualization device according to the present invention, the scale (19) indicating the relationship between the position of the weight on the second surface of the leaf spring and the natural frequency of the leaf spring is configured to measure the vibration of the leaf spring. A configuration provided on the second surface may be used.

With this configuration, the vibration visualization device according to the present invention can easily adjust the natural frequency of the leaf spring by adjusting the position (height) of the magnet based on the scale on the second surface of the leaf spring. become.

In addition, the vibration visualization device according to the present invention further comprises a housing (20) for housing the components of the vibration visualization device and having an opening (21) through which the laser beam reflected from the mirror passes, The base portion may be fixed to the housing such that the vibration of the object is transmitted to the base portion through the housing attached to the object.

With this configuration, the vibration visualization device according to the present invention can change the direction of laser light output from the opening of the housing by changing the outer surface of the housing that is brought into contact with the object. This makes it easy to display the trajectory of the laser spot by providing a screen at a suitable location among the ceiling, floor, wall, target device, and the like.

Further, the vibration visualization device according to the present invention includes a holder (25) that supports the housing rotatably around two axes (251, 252) and holds the housing at an arbitrary rotational position. Further, one of the two axes may be parallel to the surface of the mirror and intersect one end surface of the mirror.

With this configuration, the vibration visualization device according to the present invention can adjust the irradiation angle of the laser light by adjusting the rotational position of the housing about one of the two axes (the first axis) that are not parallel to each other. . Thereby, the optical magnification can be adjusted. Also, the position of the laser spot can be adjusted in the direction along the trajectory of the laser spot on the screen. Also, the direction of the laser light can be adjusted by adjusting the rotational position of the housing about the other of the two axes (the second axis). For example, if the second axis is perpendicular to the screen, it is possible to adjust the direction along the trajectory of the laser spot on the screen and the direction that intersects it.

Further, a vibration visualization device according to the present invention is a vibration visualization device (10A) for visualizing vibration of an object, comprising a base portion (11A) installed on the object, and a plurality of leaf springs (12A) fixed with the other end being a free end; a plurality of mirrors (13A) respectively fixed to the first surfaces of the plurality of leaf springs; A laser light source (15A) that emits light, and a lens (90) that is fixed to the base and converts laser light emitted by the laser light source into planar laser light including line laser light directed to all of the plurality of mirrors. ), wherein the plurality of leaf springs have different natural frequencies (Fc).

With this configuration, even if the vibration frequency of the vibration of the object fluctuates, the vibration visualization apparatus according to the present invention can resonate with the vibration of the object the leaf spring having the same or close natural frequency as the fluctuated vibration frequency. Therefore, the vibration of the object can be reliably detected and visualized by enlarging it.

Further, a device diagnostic device according to the present invention is a device diagnostic device (1) for diagnosing a state of a target device (30), which is the object, from vibration of the target device (30), wherein the vibration visualization according to any one of the above. A device (10) and a screen (50) provided outside the vibration visualization device on which the laser light emitted from the laser light source and reflected by the mirror is projected.

With this configuration, the device diagnostic apparatus according to the present invention magnifies the vibration of the target device as the amplitude of the vibration of the resonating leaf spring (mechanical magnification) and reflects it off the mirror fixed to the resonating leaf spring. A laser beam with an oscillating irradiation angle is magnified (optical magnifying) as a locus of a laser spot projected on a screen placed at a fixed distance outside the vibration visualization device. As a result, minute vibrations can be reliably detected and visualized at a high magnification rate by mechanical and optical magnification due to resonance, so that highly reliable equipment diagnosis can be performed. Moreover, since the device diagnosis apparatus of the present invention does not require an electronic circuit for signal processing and has a simple structure consisting of a small number of parts, it is easy to manufacture and the manufacturing cost is low.

Further, in the device diagnosis apparatus according to the present invention, the screen may be provided with a scale indicating the relationship between the amplitude of the locus of the spot of the laser beam and the effective value of the vibration velocity of the target device. good.

With this configuration, the device diagnostic apparatus according to the present invention can measure the effective value of the vibration velocity of the target device from the amplitude of the trajectory of the spot of the laser beam displayed on the screen.

Further, in the device diagnostic apparatus according to the present invention, the scale may be configured to associate an effective value of vibration velocity as a quantity defining vibration severity of the object with the degree of the state of the target device. .

With this configuration, the vibration visualization device according to the present invention can easily grasp the effective value of the vibration velocity of the target device and the state of the target device from the amplitude of the trajectory of the spot of the laser light displayed on the screen.

Further, a vibration visualization method according to the present invention is a vibration visualization method for visualizing the vibration of an object that vibrates at a known frequency, the vibration visualization method comprising a leaf spring having a mirror attached thereto and a weight. Adjusting the natural frequency to a known frequency of the object, irradiating a laser beam toward the mirror fixed to the leaf spring resonating with the object, and reflecting the laser from the mirror It involves shining light onto a screen to display the locus of a spot of laser light.

In the vibration visualization method according to the present invention, the vibration of the object is magnified as the amplitude of the vibration of the resonating leaf spring (mechanical magnification), and the irradiation angle reflected by the mirror fixed to the resonating leaf spring is An oscillating laser beam is magnified as a laser spot trajectory projected onto a screen (optical magnification). As a result, minute vibrations can be reliably detected and visualized at a high magnifying power by mechanical magnification and optical magnification due to resonance, so that highly reliable diagnosis can be performed, for example, in equipment diagnosis. Moreover, the vibration visualization method of the present invention does not require an electronic circuit for signal processing, and can be implemented at low cost using only a small number of components.

In addition, the vibration visualization method according to the present invention vibrates the object at the known frequency, measures the vibration speed of the object with a vibration sensor, and calculates the effective value of the measured vibration speed and the laser The configuration may further include acquiring a relationship between the amplitude of the trajectory of the light spot and providing a scale on the screen based on the acquired relationship.

With this configuration, the vibration visualization method according to the present invention refers to the scale on the screen that indicates the relationship between the effective value of the vibration velocity of the object and the amplitude of the laser spot trajectory, and the laser light spot displayed on the screen. The effective value of the vibration velocity of the object can be measured from the amplitude of the trajectory of . As a result, the state of the target device can be easily grasped based on the evaluation method of the state of the target device based on the effective value of the vibration velocity as the vibration severity defined in ISO 10816-3, for example.

Further, in the vibration visualization method according to the present invention, the step of acquiring the relationship includes a pair of values consisting of the measured effective value of the vibration velocity and the amplitude value of the trajectory of the laser beam spot, The configuration may be such that the relationship between the measured effective value of the vibration velocity and the amplitude of the trajectory of the spot of the laser light is acquired.

With this configuration, the vibration visualization method according to the present invention can quickly acquire the relationship between the effective value of the vibration velocity of the object and the amplitude of the laser spot trajectory.

Further, a device diagnostic method according to the present invention is a device diagnostic method for diagnosing the state of the target device (30), which is the object, from the vibration of the target device (30). The method further comprises determining the state of the target device based on the amplitude of the trajectory of the spot of the laser light displayed on the screen.

With this configuration, the equipment diagnosis method according to the present invention can reliably detect minute vibrations and visualize them at a high magnification rate through mechanical and optical enlargement due to resonance. can be performed at low cost.

According to the present invention, a vibration visualization device that has a simple structure consisting of a small number of parts, is easy to manufacture, has a low manufacturing cost, has a high vibration amplification factor and high reliability, and a device diagnosis device using the same, Also, a vibration visualization method and a device diagnosis method can be provided.

1 is a diagram showing a schematic configuration of a vibration visualization device according to a first embodiment of the present invention; FIG. FIG. 4 is a diagram showing a vibration visualization device housed in a housing; 1 is a perspective view of a vibration visualization device housed in a housing; FIG. FIG. 4 is a diagram showing a configuration of a holder that holds a housing; FIG. 2 is a view in the direction of arrow A in FIG. 1; It is a figure which shows a mode that the laser beam output from the vibration visualization apparatus is projected on the screen of a ceiling as the locus|trajectory of a laser spot. It is an enlarged view of the leaf spring and the damper of the vibration visualization device. FIG. 3 is a schematic diagram showing how laser light emitted from a laser light source is reflected by a mirror of a leaf spring and sent to a screen. It is a figure which shows the calibration method. FIG. 3 is a diagram showing how laser light output from a vibration visualization device attached to a rotating device is displayed as a locus of laser spots on a screen on the floor. Fig. 2 shows a drilling machine with a vibration visualization device and a screen attached; FIG. 4 is a diagram showing criteria for determining the state of a machine based on vibration severity; 4 is a graph showing resonance frequencies; 4 is a graph showing frequency response; Fig. 3 is a graph showing the amplitude of the laser spot trajectory versus the input voltage of the function generator; Fig. 3 is a graph showing the amplitude of the laser spot trajectory against velocity; 4 is a graph showing estimated values of vibration velocity; 10 is a graph showing a calibration curve; It is a flowchart which shows the outline of the apparatus diagnostic method performed using the vibration visualization apparatus which concerns on embodiment of this invention. 4 is a flowchart showing an outline of calibration work; It is a figure which shows schematic structure of the vibration visualization apparatus which concerns on the 2nd Embodiment of this invention. FIG. 4 is a schematic diagram showing how a linear laser beam is converted into a plane laser beam by a lens;

DETAILED DESCRIPTION OF THE INVENTION A vibration visualization device, a device diagnostic device, and a vibration visualization method according to embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
A vibration visualization device 10 according to this embodiment is a device that visualizes minute vibrations of a target device 30 such as a rotating device.

Examples of target equipment 30 include, but are not limited to, rotating machines such as fans, blowers, pumps, turbines, compressors, engines, drill presses, rolling mills, etc. Any equipment that vibrates at a known vibration frequency Fv. Just do it. However, if the vibration component contains harmonics, the dominant fundamental wave can be selected as the vibration frequency of interest.

FIG. 1 is a diagram showing a schematic configuration of a vibration visualization device 10 according to an embodiment of the present invention, FIG. 2 is a diagram showing the vibration visualization device 10 accommodated in a housing 20, and FIG. 1 is a perspective view of vibration visualization device 10 housed in body 20. FIG. As shown in FIGS. 1 to 3, the vibration visualization device 1 according to the present embodiment includes a base portion 11, a laser light source 15, a leaf spring 12, a mirror 13, a magnet 14, a damper 180, a housing 20. Each component will be described below.

[Base part]
The base part 11 is a plastic or metal plate-shaped pedestal that is arranged so as to contact the target device 30 directly or indirectly via the housing 20, and is normally placed inside the housing 20 for dust prevention. are to be accommodated. The base portion 11 is made of a hard material, such as acrylic, and transmits the vibration of the target device 30 transmitted through the housing 20 to the leaf spring 12 .

[Laser light source]
The laser light source 15 emits a laser beam (also referred to as a laser beam) toward the mirror 13, and is directed at a predetermined position in a predetermined direction by a laser light source mounting portion 17 fixed to the base portion 11. installed. The laser light of the present embodiment is, for example, visible light with a wavelength of 650 nm, but is not limited to this. It may be light.

The power source of the laser light source 15 may be arranged inside the housing 20, or may be supplied with power from the outside. The operation switch may be provided on the outer surface of the vibration visualization device 10 or in the vicinity of the vibration visualization device 10, or may be provided so that the laser light source 15 can be operated (power ON/OFF) by wireless or wired remote control. can be A power supply supplies DC4.5V, for example.

[Leaf spring]
The leaf spring 12 is a plate-shaped member made of a metal magnetic material, and has one end 12d fixed to the base portion 11 and the other end 12e being a free end. Specifically, the leaf spring 12 includes a leaf spring body portion 12a and a leaf spring mounting portion 12b fixed to the base portion 11. The leaf spring body portion 12a and the leaf spring mounting portion 12b are separated from each other by a predetermined connected at an angle _β0 . This connecting portion serves as the fulcrum 12c, and the plate spring body portion 12a can vibrate (rotational vibration) in the vibrating direction 70. As shown in FIG. One end and the other end of this embodiment correspond to the one end and the other end of the present invention, respectively.

The leaf spring 12 has a natural frequency (also referred to as resonance frequency) Fc equal to the known vibration frequency Fv of the target device 30 .

[mirror]
The mirror 13 is a plane mirror, and is fixed to the first surface 12a1 of the leaf spring 12 so as to reflect the laser light emitted from the laser light source 15. As shown in FIG. The mirror 13 vibrates together with the leaf spring 12 when the leaf spring 12 rotates about the fulcrum 12c.

[magnet]
The magnet 14 is attached to the second surface 12a2 of the leaf spring 12 at an arbitrary height so that the magnet 14 is detachably attached so that the natural frequency Fc of the leaf spring 12 can be adjusted. The magnet 14 is, for example, a permanent magnet, and functions as a mass for adjusting the natural frequency Fc of the leaf spring 12, and cooperates with a plate-like member 18 made of a non-magnetic metal to be described later to cause the leaf spring 12 to vibrate. and the function of attenuating the It should be noted that the magnet 14 corresponds to the weight of the present invention.

The plate spring 12 to which the magnet 14 and the mirror 13 are attached is called a "plate spring system". The natural frequency of the leaf spring 12 means the natural frequency of the leaf spring system 120 .

(Scale for natural frequency adjustment)
FIG. 5 is a view of the leaf spring 12 of FIG. 1 as viewed from the non-magnetic metal plate member 18 side. As shown in FIG. 5, the second surface 12a2 of the leaf spring 12 is provided with a scale 19 that indicates the relationship between the position of the magnet 14 and the natural frequency Fc. The magnet 14 is marked with an arrow 14a. The natural frequency Fc of the leaf spring 12 can be easily adjusted by adjusting the position of the magnet 14 in the height direction (Z direction) of the leaf spring 12 while referring to the scale 19 and the arrow 14a. .

[Damper]
The damper 180 moderately attenuates the vibration when the vibration of the leaf spring 12 is large. The damper 180 is composed of a non-magnetic metal plate-like member 18 and a magnet 14. One end 18d of the damper 180 is located at the base portion 11 so that the non-magnetic metal plate-like member 18 is arranged at a constant distance d from the magnet 14. , and the other end 18e is a free end. Specifically, the non-magnetic metal plate-shaped member 18 is made of, for example, a copper plate. The non-magnetic metal plate-shaped member body portion 18a and the non-magnetic metal plate-shaped member fixing portion 18b are connected at a predetermined angle _β0 at the connecting portion 18c. Unlike the plate spring 12, the plate-like member 18 made of non-magnetic metal is configured so as not to rotate and vibrate.

[Chassis]
As shown in FIGS. 2 and 3, the housing 20 has a hollow rectangular parallelepiped shape, and has a housing body portion 20a and a lid portion 20b. The housing 20 is used (1) for dust protection and (2) for adjusting the direction of the laser beam and the optical magnifying power in combination with the holder 25 . The housing 20 accommodates the components of the vibration visualization device 10 as necessary, and the one surface portion 20a1 has an opening 21 as a laser light exit through which the laser light 80 reflected from the mirror 13 passes. formed. The opening 21 is covered with a transparent plate 22 to prevent dust from entering the housing 20 through the opening 21 . A through hole 23 through which a cable 16 for power supply and control of the laser light source 15 passes is also formed in the same surface portion 20a1 or the other surface portion. The base portion 11 is firmly fixed to the housing 20 so that the vibration of the target device 30 is transmitted to the base portion 11 through the housing 20 . As a result, even if any surface portion of the housing 20 is placed against the target device 30, the vibration of the target device 30 is transmitted to the leaf spring 12 via the housing 20 and the base portion 11. . The size of the housing is, for example, 20×30×40 mm.

As shown in FIG. 3 , rotation center portions 24 are provided on the facing outer surface portions 20 a 2 and 20 a 3 of the housing 20 . A straight line connecting these two rotation center portions 24 and extending is referred to as a first axis line 251 . The rotation center 24 is provided at a position that satisfies the condition that the first axis 251 is parallel to the surface of the mirror 13 and intersects the one end face 13b of the mirror 13 . This condition is also satisfied when the first axis 251 is parallel to the surface of the mirror 13 and is in contact with or in the vicinity of the surface of the mirror 13 . The rotation center portion 24 has a structure in which the housing 20 is rotatably supported by the holder 25 . For example, the center of rotation 24 may have a rotation axis or bearing, and the holder 25 may have a corresponding bearing or rotation axis.

[holder]
FIG. 4 is a diagram showing the configuration of the holder 25 that holds the housing 20. As shown in FIG. A holder 25 is used with the housing 20 to adjust the direction of the laser light and the optical magnification. As shown in FIG. 4 , the holder 25 includes two side plates 25 facing each other with the housing 20 interposed therebetween, and a bottom plate 27 connecting the lower ends of the side plates 25 . The holder 25 has an adjusting screw 28 on the side plate 26 and an adjusting screw 29 on the bottom plate 27 .

The holder 25 rotatably supports the housing 20 around a first axis 251 and a second axis 252 that are not parallel to each other, and holds the housing 20 at an arbitrary rotational position. Here, the first axis 251 is an axis that passes through the center of the adjusting screw 28, is parallel to the surface of the mirror 13, and intersects the end face 13b of the mirror 13. As shown in FIG. A second axis 252 is an axis passing through the center of the adjusting screw 29 and extending in a direction perpendicular to the screen 50 .

The housing 20 is attached to the holder 25 and the holder 25 is fixed to the object 30 . When the adjusting screw 28 is loosened, the housing 20 can be rotated in the direction of _θx , and when the adjusting screw 28 is tightened, the rotational position around the first axis at that time is fixed. . When the adjusting screw 29 is loosened, the housing 20 can rotate in the direction of _θh , and when the adjusting screw 29 is tightened, the rotational position about the second axis at that time is fixed. ing.

With this configuration, the irradiation angle Θ ₀ of the laser light can be adjusted by adjusting the rotational position of the housing 20 about the first axis 251 . That is, the position of the laser spot can be adjusted in the adjustment direction 102 in the x-axis direction along the trajectory of the laser spot on the screen 50 . Since the optical magnifying power is represented by the formula (7) described later, the optical magnifying power can be adjusted by adjusting the irradiation angle _Θ0 . Also, by adjusting the rotational position of the holder 25 about the second axis 252, the direction of the laser beam can be adjusted. Specifically, the position of the laser spot can be adjusted in the adjustment direction 101 on the screen 50 .

<Description of operation>
As described above, the vibration visualization device 10 includes a laser light source 15, a magnetic leaf spring 12, a mirror 13 fixed to the leaf spring 12, a magnet 14 as a weight whose position can be adjusted with respect to the leaf spring 12, and a non-magnetic material. A plate member 18 made of a magnetic metal, such as a copper plate, is provided. A plate spring 12 is fixed to a base portion 11 fixed to a bottom portion of a housing 20 of the vibration visualization device 10, a mirror 13 is fixed to the plate spring 12, and a magnet 14 is attached. With this configuration, a cantilever beam resonance (cantilever) system centering on the fulcrum 12c, which is the fixing portion of the leaf spring 12, is formed, and the leaf spring 12 forms a rotary vibration system centering on the fulcrum 12c.

The mirror 13 fixed to the leaf spring 12 resonates with the vibration of the target device 30 (known vibration frequency Fv), and rotates around the fulcrum 12c of the leaf spring 12 . The mirror 13 of the plate spring system 120 resonating with the target device 30 is irradiated with laser light from the laser light source 15 . A laser beam reflected from the mirror 13 at a direction angle corresponding to the magnitude of the rotational vibration is taken out from the opening 21 of the housing 20 as an output laser beam. The output laser light is applied to a screen 50 arranged outside the vibration visualization device 10 and projected as a laser light spot trajectory (hereinafter also referred to as a “laser spot trajectory”) on the screen 50 .

As described above, if the natural frequency Fc of the leaf spring system 120 and the vibration frequency Fv of the target device 30 are the same, the minute vibration of the target device 30 resonates as the rotational vibration of the leaf spring system 120 and mechanically expands greatly. be done. Then, the rotational vibration of the plate spring system 120 is optically magnified as the amplitude of the laser spot trajectory by the principle of the optical lever. Specifically, the reflected laser beam reflected by the mirror 13 is proportional to the distance from the mirror reflection point to the screen 50 and the square of the cosine of the irradiation angle of the laser beam onto the screen 50 according to the principle of optical lever. is optically magnified in inverse proportion to .

(Adjustment of natural frequency)
As described above, the leaf spring 12 has the magnet 14 as a position-adjustable weight for adjusting the natural frequency Fc of the leaf spring system 120 . As shown in FIG. 7, by adjusting the height position of the magnet 14 in the leaf spring 12, that is, the position in the longitudinal direction 71 of the leaf spring 12, the natural frequency Fc of the leaf spring system 120 can be continuously adjusted. can be done. The magnet 14 may be fixed with an adhesive or the like at a location where the natural frequency Fc of the leaf spring system 120 matches the known vibration frequency Fv of the target device 30 .

The Q value at the natural frequency Fc of the leaf spring system 120 is large, and when the vibration frequency Fv of the target device 30 does not change, the vibration of the target device 30 is magnified to the vibration of the leaf spring system 120 due to mechanical resonance. The Q value can be adjusted by the close distance between the magnet 14 and the copper plate 18, which is a plate-shaped member of non-magnetic metal. When the proximity distance is narrowed, the attenuation coefficient is increased (the Q value is decreased and the half width Δf is widened), and when the proximity distance is increased the attenuation coefficient is decreased (the Q value is increased and the half width Δf is narrowed).

On the other hand, when the vibration frequency Fv of the vibration of the target device 30 fluctuates, the fluctuation greatly affects the magnification of the vibration. In this case, it is necessary to take measures to cope with frequency fluctuations, even at the expense of strong resonance characteristics. That is, it is necessary to reduce the Q value. The Q value is inversely proportional to the damping coefficient of the resonant system. Therefore, in order to reduce the Q value, it is preferable to increase the attenuation coefficient.

(Damper action)
Use of a damper can be considered as a measure to increase the damping coefficient. A contact damper is not suitable because it affects vibration, and a non-contact damper is preferable. In this embodiment, after the position of the magnet 14 for adjusting the natural frequency is adjusted and fixed, a copper plate 18 made of non-magnetic metal is fixed so as to be adjacent to the magnet 14 without contact.

As mentioned above, the copper plate 18 is fixed adjacent to the magnet 14 at a location where it does not contact the magnet 14 . The magnetic field from magnet 14 penetrates copper plate 18 . The leaf spring 12 vibrates due to the mechanical vibration of the target device 30, and the magnet 14 also vibrates accordingly. As a result, the magnetic field penetrating the copper plate 18 changes due to the vibration caused by the relative vibration difference between the leaf spring 12 and the copper plate 18 (the leaf spring 12 resonates and has a large amplitude, but the copper plate 18 is not a spring and has a small amplitude). Then, an electromotive force is generated and an eddy current is generated in the copper plate 18 . Due to copper loss (ohmic loss) due to eddy currents, vibrational energy is dissipated as thermal energy, producing a vibration damping effect. Thus, the copper plate 18 functions as a non-contact damper for the leaf spring 12 . The damping of the vibration reduces the Q value, thereby widening the resonance frequency width (half width Δf), so that frequency fluctuations of mechanical vibration can be dealt with. The loss of vibrational magnification due to the reduction of the Q factor can be compensated for by optical magnification.

[Equipment diagnosis device]
Next, the device diagnostic device 1 will be described.

The device diagnostic device 1 diagnoses the state of the target device 30 from the vibration of the target device 30, and includes a vibration visualization device 10 and a screen 50, as shown in FIG. The device diagnostic apparatus 1 according to the present embodiment can be mechanically and optically magnified to the extent that minute vibrations with an amplitude of 0.0064 mm, for example, can be visualized.

[screen]
The screen 50 is provided outside the vibration visualization device 10, and the laser light 80 emitted from the laser light source 15 and reflected by the mirror 13 is projected as a Lissajous figure-shaped laser spot trajectory (in most cases, linear). It has become so. The screen 50 may be provided on the ceiling, floor, wall, or the like of the facility where the target device 30 is installed, or may be provided separately on the target device 30 . The ceiling, floor, wall surface, housing of the target device 30, or the like itself may be used as the screen 50. FIG. The screen surface can be selected by changing the installation direction of the vibration visualization device 10 or the angles θ _x and θ _h of the holder 25 .

[scale]
FIG. 10 is a diagram showing how laser light output from the vibration visualization device 10 attached to the target device 30, which is a rotating machine, is projected as a laser spot trajectory 82 onto the screen 50 on the floor 41. FIG. As shown in FIG. 10 , the screen 50 is provided with a scale 51 indicating the relationship between the amplitude of the laser spot locus 82 and the effective value of the vibration velocity of the target device 30 . The scale 51 has, for example, a mark that associates the effective value of the vibration velocity as the vibration severity of the target device 30 with the state of the target device 30 . "Vibration severity" is a practical index for indicating the intensity of vibration of a rotating machine, and is defined by the effective value (rms value) of vibration velocity.

FIG. 6 is a diagram showing how the laser light output from the vibration visualization device 10 is projected onto the screen 50 on the ceiling as a laser spot trajectory 82. As shown in FIG. Taking FIG. 6 as an example, the scaling relating the amplitude of the laser spot locus 82 on the screen 50 to the vibration velocity will be described with reference to FIG.

In FIG. 8, a perpendicular line is drawn from the reflection point of the laser beam on the mirror 13 (referred to as a mirror reflection point) to the screen surface 50a, and the point at which the perpendicular line and the screen surface 50a intersect is the origin O. In FIG. Let L be the length from the mirror reflection point 13a to the origin O. When the target device 30 is stopped and not vibrating, the irradiation point _x0 on which the laser beam is irradiated on the screen surface 50a is the length from the origin _O to the irradiation point _x0 . When the target device 30 is in operation, the effective value of the vibration velocity at the installation point of the vibration visualization device ₁₀ is v1, and the amplitude of the laser spot trajectory at this time is the length on the screen 50 when measured from the origin O Let the height be x ₁ . Using the effective value _v1 of the vibration velocity measured by the existing vibrometer, the velocity can be scaled on the straight line (x-axis) onto which the laser spot trajectory is projected.

Specifically, using the above measured values L [mm], x ₀ [mm], x ₁ [mm], and v ₁ [mm/s], the calibration coefficient c of the following equation is obtained.

When the object device 30 is vibrating, if the amplitude of the laser spot trajectory is x, the effective value v of the vibration speed is represented by the following equation.

The amplitude x of the laser spot locus at the effective value v of the vibration velocity is given by the following equation.

From the above relational expression, the scale of the effective value of the vibration velocity can be marked on the screen 50 on which the laser spot trajectory is projected.

The optical magnification is given by the following equation.

The optical magnification is proportional to the distance L from the mirror reflection point 13a to the screen 50 and inversely proportional to the square of the cosine of the irradiation angle Θ ₀ =tan ⁻¹ (x ₀ /L) of the laser beam. If x ₀ >>L, the laser spot trajectory shifts further away, but optionally the optical magnification can be increased. Further, for example, if the housing 20 of the vibration visualization device 10 shown in FIG. 6 is made rotatable at any angle, the magnification of this optical system can be easily adjusted. For this purpose, the above-described holder 25 (direction/optical magnification adjustment table) can be used.

The holder 25 has a structure for rotatably supporting the vibration visualization device 10 . By adjusting the angle of the housing 20 with the holder 25, the direction of the laser light and the optical magnification can be adjusted.

Next, a description will be given of the marking of evaluation classifications for the vibration state of the machine (target device 30) based on the vibration severity defined in ISO 10816-3.

As shown in Figure 12, the vibration severity specified in ISO 10816-3 is A (good), B (acceptable), C (warning), and D (dangerous).

In this embodiment, on the screen 50, a straight line on the locus of the laser spot is marked with a scale in units of vibration velocity [mm/s]. Since the magnitude and installation of the machine power is known on site and the speed scale is provided, the ISO standards determined by the above vibration speeds (e.g. A (good), B (acceptable), C (warning)) , D (danger), etc.) can also be marked on this scale.

FIG. 10 shows the memory of the vibration velocity and the ISO standard on the screen 50 on the floor. The calibration coefficient c in FIG. 10 is the width b, thickness h, length l, Poisson's ratio ν, Young's modulus E, distance L between the mirror reflection point and the screen, irradiation angle Θ ₀ =tan ⁻¹ (x ₀ /L) and the radius of gyration r, it is determined by the following equation.

However, the target device 30 is a rigid body, and the vibration rotation radius r from the measurement point (the position where the vibration visualization device 10 is installed) is not easily known. The above calibration coefficient c is theoretically derived from dynamics and an optical model, and in this embodiment, a method of calibration using the measured values of the vibration meter is adopted as described above.

[Operating principle]
Next, the principle of operation of the device diagnosis apparatus 1 according to this embodiment will be described in detail.

(Model of enlargement due to mechanical resonance)
Expansion due to mechanical resonance will be explained using the following physical model. That is, let b be the width of the leaf spring 12, h be the thickness, l be the length from the fulcrum 12c to the load, ν be the Poisson's ratio of the leaf spring material, and E be the Young's modulus. In this case, the spring constant k of the cantilever leaf spring 12 having a rectangular cross section is expressed by the following equation.

To simplify the theoretical development, the leaf spring 12 is a rigid rod, the center of gravity of the leaf spring 12 is at a height l from the fulcrum 12c, and the rigid rod-like leaf spring 12 with a spring constant k is vertically supported. Assume that Assume that the mass m is at the center of gravity. Let D be the damping coefficient. The magnitude of damping coefficient D is determined by the positions of copper plate 18 and magnet 14 . Let δθ be the vibration angle of the plate spring 12 around the fulcrum 12c, and _δθv be the vibration angle of the target device 30 . The rotational motion equation of this dynamic system is given by the following equation.

Equation (2) is represented by a quadratic transfer function as follows.

The _damping coefficient D of the leaf spring 12 is small, and this transfer function exhibits second-order vibration characteristics.

Given a leaf spring 12, the parameters E, ν, b, h are fixed and the natural frequency is adjusted by changing the length l, ie by changing the position of the center of gravity. When the leaf spring 12 is a magnetic material, the magnet 14 attracted onto the leaf spring 12 is temporarily moved as a weight for adjustment, and after the adjustment is fixed by an adhesive or the like, the length l is adjusted and fixed.

The gain G of the angle _{.delta..theta} .

The adjustable parameter is length l and the gain is proportional to the value of l ^1/2 .

(magnification by optical system)
Next, the enlargement by the optical system will be explained. FIG. 8 is a schematic diagram showing a state of optical enlargement. Let α ₀ be the irradiation angle of the laser beam emitted from the laser light source 15 and β ₀ be the rising angle of the leaf spring 12 in the stationary state with respect to the horizontal line. As shown in FIG. 8, the angular enlargement of the leaf spring 12 is Gδθ _v due to resonance according to the equation (5), and the rising angle θ ₂ of the leaf spring 12 is β ₀ −Gδθ _v , which is the horizontal plane of the laser beam. The angle θ ₃ from is π+α ₀ −2(β ₀ −Gδθ _v ).

The screen 50 has a flat screen surface 50a onto which the laser spot locus 82 is projected. The position and angle of the screen 50 are arbitrary as long as it receives the laser light. The point at which a straight line drawn from the reflection point of the mirror 13 perpendicular to the screen 50 intersects the screen surface 50a is the origin O, and the length between the origin O and the reflection point of the mirror 13 is L. The x-axis is an axis line passing through the origin O and extending along the laser spot locus 82 on the screen surface 50a. When not vibrating, the laser spot is assumed to be at coordinate point x0 on the _x -axis.

From FIG. 8, the angle Θ ₀ is Θ ₀ =tan ⁻¹ (x ₀ /L), and when the angle changes from Θ ₀ by θ ₁ =2Gδθ _v due to vibration, the laser spot trajectory on the x-axis becomes Become.

Assuming 2G δθ<<Θ ₀ gives the magnification in the linear range of this system. The following equation is obtained by expanding the equation (6) around Θ ₀ by Taylor series expansion to the 2Gδθ _v term.

Therefore, the magnification of the optical system is as follows.

The magnification of the optical system is linearly proportional to the distance L to the screen 50 and inversely proportional to cos ² Θ ₀ .

(Total magnification and simulation by mechanical resonance and optics)
Assuming that the vibration radius of rotation r of the target device 30 is known, the vibration δx _v of the target device 30 =rδθ _v , and from the amplitude δx of the laser spot trajectory and the vibration δx _v of the target device 30, the magnification ratio is as follows: become.

It is assumed that the vibration of the target device 30 occurs at a single frequency, and that frequency is given by equation (4-1). Therefore, the magnification rate of the velocity given as the laser spot trajectory from the vibration displacement of the target device 30 is given by the following equation.

From equations (7), (8), and (9), the expanded rotational angular vibration 2Gδθ _v of equation (6) is given by the following equation.

The calibration coefficient c in equation (10) includes all of the leaf spring system, the optical system, and the unknown radius of gyration r of the target device 30 . Equations (10) to (6) are given as functions of vibration velocity v as follows.

The calibration factor c includes the unknown parameter, the radius of gyration r, and must be determined by a vibrometer.

Based on the above theoretical model, the magnification based on the resonance of the leaf spring 12 at the resonance frequency, the magnification due to optical magnification, and the overall magnification due to the vibration rotation radius of the target device 30 are calculated under the following conditions. The conditions are almost the same as the experimental conditions described in Example 1 below.

Leaf spring 12 width b=6×10 ⁻³ m, thickness h=0.1×10 ⁻³ m, length from fulcrum to center of gravity l=15×10 ⁻³ m, mass m=1×10 ^{− 3} kg, Poisson's ratio ν=0.3 (spring steel), Young's modulus E=206×10 ⁹ N/m ² (spring steel), oscillating radius of gyration r=0.1 m, and damping coefficient D=1.43× 10 ⁻⁶ N·m·s/rad. The damping coefficient D is a value obtained on the assumption that the damping rate ζ=0.01 rad/s.

From the equations (4-1) to (4-4), the resonance frequency f _r = 50.48 Hz, the damping factor ζ = 0.01 rad/s, the half width Δf = 1 Hz, and the Q value Q = 50, and (5) From the equation, the expansion ratio based on the mechanical resonance of the leaf spring 12 is |θ/θ _v |=50. For a distance x ₀ =515 mm and L=100 mm, from equation (7), the gain due to optical magnification |δx/Gδθ _v |=105 m/rad and the total gain |δx/δx _v |=52500.

By changing the position of the magnet 14 on the leaf spring 12 which adjusts the length l, the resonance frequency can be adjusted. FIG. 13 shows changes in resonance frequency with respect to changes in length l (position in the height direction from the fulcrum 12c of the weight). In this model, since the damping coefficient D is calculated from the damping rate ζ, the gain at resonance is constant at 1/2σ.

From the equations (8) and (9), the amplitude of the vibration displacement and the amplitude of the vibration velocity given by the laser spot trajectory are inversely proportional to the magnitude of the damping coefficient D. Therefore, in order to increase the magnification in mechanical resonance, the leaf spring 12 should be made to resonate with the vibration of the target device 30 and the damping coefficient D should be reduced.

On the other hand, the half width at resonance widens in proportion to the value of the damping coefficient D. For example, in the above theoretical calculation, the half width was Δf=1 Hz. Assuming that the resonance frequency is 50 Hz, an amplitude fluctuation of 3 dB (1/√2 to 1) occurs when the vibration frequency of the target device 30 changes within the range of 50±0.5 Hz. In order to increase the gain in the mechanical resonance method, the damping coefficient D must be decreased, while in order to widen the half-value width, the damping coefficient D must be increased.

It is true that the half width is linearly proportional to the damping coefficient D from the equation (4-3). Further, from equations (7), (8), and (9), the overall magnification and optical magnification are proportional to L/cos ² (Θ ₀ ). By making Θ ₀ closer to 90° or choosing a longer L, the overall magnification can be arbitrarily increased. As a result, the reduction in magnification due to widening the half-value width to deal with frequency fluctuations can be compensated for by optical magnification.

(Calibration and scaling of laser spot trajectory displacement)
According to the ISO 10816-3 standard, vibration severity is determined by the vibration velocity root mean square value. Here, the relationship between the amplitude of the laser spot trajectory and the vibration velocity and how to create a velocity scale on the screen 50 onto which the laser beam is projected are shown.

When the linear magnification of the optical system was obtained from equation (7), it was assumed that the vibration angle would change only within a small range. However, when the vibration angle increases, it enters the nonlinear region due to the tan function. Here, calibration methods and scaling methods including non-linear ranges are described. As shown in FIG. 8, the laser spot trajectory emitted from the vibration visualization device 10 is projected on a flat screen 50 at any angle and position such as the factory wall, ceiling, floor, housing of the target device 30, etc. be.

(11), the laser spot trajectory x is given as a function of the vibration velocity v. This function contains an unknown calibration factor c. The vibration velocity v of the target device 30 can be measured with a vibration meter. Let the measured vibration velocity be _v1 and the measured amplitude of the laser _spot trajectory at the x coordinate be x1. By substituting these measured values v ₁ and x ₁ and the position x 0 of the laser spot when the object is not vibrating and the length L of the distance to the screen of the apparatus into equation (11), the calibration coefficient c is You are asked to:

When measuring multiple amplitudes and vibration velocities of the laser spot trajectory at the same time, the calibration coefficient c can be calculated from these data by the average value or the least squares method. Using the estimated calibration factor c, the scale of the velocity v on the x coordinate is found by substituting the calibration factor c into equation (12). With the attached scale, the vibration speed can be visually observed on the x-coordinate, and if the scale is colored with A (blue), B (green), C (yellow), and D (red) based on the ISO 10816-3 standard, the vibration is severe. The state of the target device 30 based on the property can also be determined visually. Further, when the value of the vibration velocity v is required, it can be calculated from the measured amplitude x of the laser spot trajectory by the following equation.

Next, Example 1 will be described.

(Device configuration)
A vibration visualization device 10 shown in FIGS. 2 and 3 was manufactured. The leaf spring 12 is made of hardened steel, has a Poisson's ratio ν=0.3, a Young's modulus E=206×10 ⁹ N/m ² , and has a width b=6×10 ⁻³ m and a thickness b=6×10 9 N/m 2 . height h=0.1×10 ⁻³ m and maximum length l=25×10 ⁻³ m. The total weight of leaf spring 12, mirror 13 and magnet 14 (leaf spring system 120) is 1.1×10 ⁻³ kg.

The laser light source 15 (ANBE Electronics Co. Ltd, Vietnam) has a wavelength of 650 nm, a spot diameter of 6 mm, is covered with a copper housing of 7 mm diameter, and is class II. The mirror 13 has a thickness of 1 mm, a size of 6 mm×6 mm, and is deposited on glass. The angle of the optical axis of the laser beam with respect to the horizontal plane is approximately α ₀ =35°, and the angle of the leaf spring 12 is approximately β ₀ =70°. Finally, the angle of the leaf spring 12 was finely adjusted so that the angle γ ₀ of the optical axis of the exit laser beam with respect to the horizontal plane was γ ₀ =84°.

The natural frequency Fc of the plate spring system 120 can be adjusted by changing the position of the magnet 14 in the height direction. The natural frequency Fc of the leaf spring 12 was approximately 60 Hz when the magnet 14 was at its lowest position, and was approximately 30 Hz when it was at its highest position. At the position of the magnet 14 shown in FIG. 2, the natural frequency Fc of the plate spring system 120 was 50 Hz.

According to the specifications of the vibration meter used for calibration (SMART SENSOR model: AS63B, serial number: 4683924, production date 2020-5-30), the acceleration range is 0.1 to 199.9 m/s ² peaks, the velocity range is 0 .1-199.9 mm/s rms, with a displacement range of 0.001-1.999 mmP-P. These errors at a frequency of 40 Hz are −0.1 m/s ² , 0.1 mm/s and 0.0001 mm respectively.

(performance test)
FIG. 9 is a diagram showing the outline of the device configuration in the performance test conducted using the test vibration generator 66. As shown in FIG. A sine wave generated by the function generator 60 is amplified by an audio amplifier 61 to drive a voice coil motor 62 . This vibration is called test vibration. A vibration detector 64 of a calibration vibrometer 65 is applied to a test vibration generator 66 . Vibration visualization device 10 is also attached to test vibration generator 66 .

The vibration visualization device 10 is adapted to project the laser spot locus 82 onto a flat horizontal screen 50 . The laser beam exit surface (the surface with the opening 21) of the housing 20 of the vibration visualization device 10 is installed vertically, and the height L of the center of the laser beam output from the housing 20 is L = 65 mm. The x-coordinate x0 of the stationary spot on the screen 50 when no was occurring was x ₀ =515 mm. The peak value of vibration acceleration, vibration velocity, and vibration displacement PP measured by the vibration meter 65 were 0.3 m/s ² P, 0.6 m/s rms, and 0.006 mm PP, respectively. . On the other hand, the amplitude Am of the laser spot locus 82 from x0 to the positive _x -axis direction (rightward direction in FIG. 9) was 115 mm. Therefore, the magnification of vibration displacement was 115 mm/(0.006 mm/2)=38333 (91.6 dB).

(frequency response)
A test vibration was generated in the device configuration of FIG. 9 to examine the frequency response. The input voltage of function generator 60 was set to 400 mV. FIG. 14 shows the frequency response of the vibration visualization device 10 with the natural frequency adjusted to 50 Hz in the vibration frequency range of 45 Hz to 65 Hz. The frequency characteristics are shown for the case without the damper, with the copper plate 18 removed, and for the case with the damper, with the copper plate 18 placed behind the magnet 14 at a distance of 0.4 mm.

As shown in FIG. 14, at the natural frequency of 50 Hz, the amplitude was 125 mm without the copper plate 18 and the amplitude was 29.5 mm with the copper plate 18 . That is, when the copper plate 18 was present, it was 25.6% of when the copper plate 18 was absent. Further, the half-value width without the copper plate 18 was 0.96 Hz, the Q value was Q=52, and the attenuation factor was .zeta.=0.0096. On the other hand, when the copper plate 18 was present, the half width was Δf=4 Hz, the Q value was Q=12.5, and the attenuation factor was ζ=0.04. That is, the amplitude changed by 3 dB in the frequency range of 50±0.43 Hz without the copper plate 18, whereas the frequency band in which the amplitude changed by 3 dB was 50±2 Hz with the copper plate 18 present.

The attenuation coefficient D is determined by the gap between the magnet 14 and the copper plate 18, but this value is a trade-off between the magnification and the frequency band. The optimum gap is determined by the fluctuation range of the vibration frequency of the target device 30. FIG. A wide gap (that is, a small damping coefficient D) should be selected when the fluctuation of the vibration frequency is small, and a narrow gap (that is, a large damping coefficient D) should be selected when the fluctuation of the vibration frequency is large.

(Measurement of speed)
In order to examine the frequency response of the device configuration shown in FIG. 9, test vibration was generated under the following conditions. The frequency of the function generator 60 was fixed at 50 Hz, and the input voltage of the function generator 60 was varied from 0 mV to 760 mV. At voltages below 100 mV, the level of test vibration is below the lower limit of the vibrometer 65 used and cannot be measured in this range. FIG. 15 shows the amplitude of the laser spot trajectory versus the input voltage of function generator 60 .

In FIG. 15, the slope of the graph increases with increasing voltage and is not linear. In the voltage range of 0 to 100 mV, which cannot be measured by vibrometer 65, the amplitude of laser spot locus 82 increases linearly with increasing voltage. Therefore, in this embodiment, minute vibrations that cannot be measured by the conventional vibrometer 65 can be measured.

FIG. 16 shows the relationship between the vibration velocity measured by the conventional vibrometer 65 and the amplitude of the laser spot locus 82 . When the vibration speed varies in the range of 0.2 mm/s to 1.7 mm/s, the amplitude of the laser spot locus 82 varies in the range of 40 mm to 590 mm and can be visually confirmed even from a distance. The trend of the amplitude of the laser spot locus 82 with respect to velocity is the same as the trend with respect to the applied voltage (input voltage) to the function generator 60 .

In FIG. 9, the height L of the center of the laser beam output from the housing 20 is L ₌ 65 mm, and when the test vibration generator 66 is not vibrating, the displacement x0 of the spot of the laser beam is x0 = 515 mm. Moreover, when the vibration velocity was v ₁ =1.0 mm/s, the displacement was x ₁ =630 mm. When the calibration coefficient c is obtained from these values by the equation (12), it is c=0.0379 rad/(mm/s). Substituting the value of the calibration coefficient c into equation (11), the vibration velocity v is calculated from the amplitude x of the laser spot trajectory. FIG. 17 shows the relationship between the measured velocity measured by the vibrometer 65 and the estimated velocity calculated by equation (13).

The estimated velocity is linearly proportional to the measured velocity with a slope of approximately unity. Therefore, the velocity values can be scaled by the coordinates on the screen onto which the laser spot trajectory is projected according to equation (11).

Vibration generated when a small fan (model: MMF-06G24ES) (MELCO TECHNOREX CO.LTD, 24 VDC, 0.1 A) was driven at 14.7 V was visualized by the vibration visualization device 10 . Specifically, the vibration visualization device 10 was used to irradiate the floor with a laser beam, and the floor was used as a screen to project a laser spot trajectory. The vibration frequency of the vibration generated when the small fan is driven is 60 Hz, the peak value of acceleration measured by a vibration meter is 0.4 m/s ² , the effective value of velocity is 0.5 mm/s, and the peak to peak displacement is was 0.003 mm. The vertical distance L from the floor to the center of the output laser beam of the vibration visualization device 10 was L=0.82 m, and the origin x ₀ of the laser spot locus was x ₀ =3.45 m. The amplitude of the laser spot trajectory closer to the laser light source was 1.30 m, and the amplitude farther from the laser light source was 2.80 m. Therefore, the ratio between the larger amplitude of the laser spot trajectory and the half magnitude (amplitude) of the peak-to-peak value of the vibration displacement measured by the vibration meter is 2800 mm/(0.003/2) mm= It was 1886666 (125 dB).

As shown in FIG. 12, the vibration severity specified in the ISO-101816-3 standard is evaluated by the effective value of vibration velocity [unit: mm/s]. The range of velocity effective values in the standard of FIG. , 2.8 mm/s, 3.5 m/s, 4.4 mm/s, 7.1 m/s, and 11.0 mm/s. The effective speed value in Example 2 was 0.5 m/s. Therefore, it was found that even the minimum effective value of the vibration velocity of 0.71 mm/s specified by the ISO-101816-3 standard can be enlarged to the extent that it can be sufficiently visualized.

(Measurement and diagnosis with a small drilling machine)
As an example, vibration measurement and diagnosis of the small drilling machine 30B were performed. A small drilling machine (REXON, Toyo Kogyo Co., Ltd., serial number 005605, date of manufacture 2016/06/20, 200 W) is a variable speed machine, and the experiment was conducted in the lowest speed state. The vibration frequency during operation of the small drilling machine 30B was 57 Hz. In the vibration visualization device 10B, the natural frequency of the leaf spring system 120 was adjusted to 57 Hz and attached to the side of the head of the small drilling machine 30B. FIG. 11 shows a small drilling machine 30B, a vibration visualization device 10B of this embodiment, and a screen 50. FIG. A vibration visualization device 10B without a damper was used.

The distance L from the mirror reflection point of the vibration visualization device 10B to the screen 50B was L=28.5 mm (see FIG. 8). The laser spot position x ₀ when the small drilling machine 30B is not in operation is x ₀ = 100 mm, and when the vibration velocity v ₁ during operation is v ₁ = 0.9 mm/s, the amplitude x ₁ of the laser spot trajectory is x ₁ =114 mm. These values were measured with the drill teeth removed from the small drilling machine 30B. From these measured values, the calibration coefficient c is calculated from equation (12) as follows.

Therefore, the speed scale (scale) on the x-coordinate on the screen 50 on which the laser spot locus 82 is drawn is given by the following equation from equation (11).

FIG. 18 shows a calibration curve that determines the velocity from the amplitude of the laser spot trajectory according to equation (13). With a 6 mm diameter drill tooth installed, the vibration velocity was 1.4 mm/s and the amplitude of the laser spot trajectory was 123 mm. These values are in good agreement with the calibration curve (calibration curve) in FIG.

FIG. 11 shows the speed scale 51 on the screen 50 calculated using equation (13). Here, the zones A, B, and C indicate the judgment zones A, B, and C of ISO10816-3, respectively. For example, in FIG. 11, when the amplitude of the laser spot trajectory is between 1.4 and 2.3 with reference to the scale 51, that is, when the velocity as the vibration severity is from 1.4 mm/s to 2.3 mm/s , the state of the small drilling machine 30B is classified as B (possible).

[Equipment diagnosis method]
Next, the device diagnostic method will be described.

FIG. 19 is a flow chart showing an outline of a device diagnostic method for diagnosing the target device 30 using the device diagnostic apparatus 1 according to this embodiment. As shown in FIG. 19, first, information on the frequency of vibrations that occur steadily in the target device 30 is obtained (step S10). The information may be acquired by measuring and analyzing the vibration generated in the target device 30, or if known in advance, the information may be used.

Also, the screen 50 for projecting the laser beam irradiated by the vibration visualization device 10 is determined. For the screen 50, the ceiling, floor, wall, or housing of the target device 30 may be used as a screen, or a separate screen may be prepared.

Next, the height position of the magnet 14 in the plate spring 12 is adjusted to adjust the natural frequency Fc of the plate spring system 120 to the vibration frequency Fv of the target device 30 (step S11). The height position of the magnet 14 may be adjusted based on the scale 19 provided on the second surface 12a2 of the leaf spring 12, or the natural frequency of vibration of the leaf spring 12 may be actually measured. You can do it while analyzing.

Alternatively, the height position of the magnet 14 in the leaf spring 12 may be adjusted so that the amplitude 84 of the laser spot locus 82 is maximized after the vibration visualization device 10 is attached to the target device 30 . In this case, acquisition of information on the vibration frequency of the target device 30 can be omitted.

Next, the vibration visualization device 10 is attached to the target device 30 (step S12). Which surface of the housing 20 of the vibration visualization device 10 is brought into contact with the target device 30 is determined by the location of the screen 50 . Specifically, the housing 20 is attached to the target device 30 so that the opening 21 of the housing 20 faces the screen 50 . At that time, the holder 25 may be used to adjust the direction and optical magnification of the laser beam output from the vibration visualization device 10 .

Next, calibration of the device diagnosis apparatus 1 is performed (step S13). Calibration will be explained later.

Next, laser light is emitted from the laser light source 15 to the mirror 13 fixed to the plate spring 12 resonating with the target device 30 in operation (step S14). Then, the laser beam 80 reflected from the mirror 13 is applied to the screen 50 to project a laser spot trajectory 82 (step S15).

The operator confirms the vibration state of the target device 30 from the trace 82 of the laser spot based on the scale 51 provided on the screen 50 (step S16). The screen 50 may be photographed by a camera, and the photographed image may be displayed on a remote display connected via a network to confirm the status of the target device 30 .

As described above, in the vibration visualization method according to the present embodiment, the vibration of the target device 30 is magnified (mechanically magnified) as the amplitude of the vibration of the resonating leaf spring 12 and fixed to the resonating leaf spring 12. The oscillating laser beam reflected by the mirror 13 is enlarged as a laser spot locus 82 on the screen 50 (optical enlargement). In this way, by utilizing mechanical and optical magnification due to resonance, minute vibrations can be reliably detected and visualized at a high magnification rate, enabling highly reliable equipment diagnosis. . Moreover, the vibration visualization method according to the present embodiment does not require an electronic circuit for signal processing, and can be implemented at low cost using only a small number of components.

[Calibration method]
Next, a calibration method will be described.

First, the origin O on the screen 50 is determined while the operation of the target device 30 is stopped. Then, the distance L from the emission point of the laser light to the screen 50, that is, the distance L from the emission point of the laser light to the origin O on the screen 50 is measured.

Next, when the target device 30 is stopped, the position _x0 of the laser spot when the target device 30 is not vibrating is measured, and a mark is added on the screen 50 so that the position can be known (step S20). ). From the distance L from the laser beam emission point to the screen 50 and the distance from the origin _O to the position x0, the irradiation angle _Θ0 is obtained.

Next, the target device 30 is operated, and the vibration velocity _v1 when the target device 30 is vibrated at a known vibration frequency Fv is measured by an existing vibrometer (step S21).

Next, using the device diagnosis apparatus ₁ , the amplitude x1 of the laser spot trajectory is measured when the target device 30 vibrates at a known vibration frequency Fv (step S22).

Using the vibration velocity _v1 and the amplitude x1 of the laser _spot locus, the calibration coefficient c is calculated from the above equation (12) (step S23). Then, a calibration curve is acquired based on the calibration coefficient c (step S24).

Thus, based on _a pair of values consisting of the measured rms value v1 of the vibration velocity and the amplitude value x1 of the laser _spot trajectory 82, the rms value v of the vibration velocity and the amplitude x of the laser spot trajectory 82 (calibration curve) can be quickly obtained.

Next, based on the calibration curve, the screen 50 is marked (step S25).

As described above, the vibration visualization method according to the present embodiment refers to the scale 51 on the screen 50, which indicates the relationship between the effective value of the vibration velocity of the target device 30 and the amplitude of the laser spot locus 82. The vibration state of the target device 30 can be easily grasped from the projected laser spot trajectory 82 .

(action/effect)
Next, functions and effects will be described.

In the vibration visualization device 10 according to this embodiment, the leaf spring 12 has a natural frequency Fc equal to the known vibration frequency Fv of the target device 30 . With this configuration, when the vibration of the target device 30 is transmitted to the leaf spring 12 via the base portion 11 installed in the target device 30, the leaf spring 12 synchronizes with the vibration of the target device 30 and rotates at the natural frequency Fc. It will vibrate (resonate). That is, the vibration of the target device 30 is magnified as the amplitude of the vibration of the resonating leaf spring 12 (mechanical magnification).

A laser beam emitted from a laser light source 15 is reflected by a mirror 13 fixed to a resonating leaf spring 12 and output as a vibrating laser beam. The vibrating laser beam is a laser beam whose direction vibrates in synchronization with the vibration of the target device 30. For example, the screen 50 arranged outside the vibration visualization device 10 is irradiated with a laser spot on the screen 50. can be displayed as a trajectory 82 of . That is, the vibrating laser light generated by the vibration of the resonating leaf spring 12 is expanded as a locus 82 of the laser spot projected on the screen 50 placed at a certain distance from the vibration visualization device 10 ( optical magnification).

Therefore, the vibration visualization device 10 according to the present embodiment does not require an electronic circuit for signal processing, and has a simple structure made up of a small number of parts. It is inexpensive, and mechanical and optical magnification due to resonance can reliably detect minute vibrations and visualize them at high magnification.

Further, in the vibration visualization device 10 according to the present embodiment, the magnet 14 as a weight is detachably attached to an arbitrary position on the second surface 12a2 of the leaf spring 12 so that the position of the second surface 12a2 of the leaf spring 12 is adjustable. You can adjust the number. With this configuration, by adjusting the position (height) of the magnet 14 on the second surface 12 a 2 of the leaf spring 12 , it becomes easy to cause the leaf spring 12 to resonate with the vibration of the target device 30 .

Further, in the vibration visualization device 10 according to the present embodiment, the damper 180 has a copper plate 18, and one end 18d is fixed to the base portion 11 so that the copper plate is arranged at a constant distance d from the magnet 14. ing. With this configuration, the vibration of the leaf spring 12 causes the magnet 14 attached to the second surface 12a2 of the leaf spring 12 to approach or separate from the copper plate 18 of the damper 180. Eddy currents are generated. Vibrational energy is dissipated as heat energy due to ohmic loss caused by eddy currents, exhibiting a vibration damping effect. Thereby, the vibration of the leaf spring 12 is suppressed. As a result, the half-value width of the leaf spring 12 during resonance is widened, and the leaf spring 12 can resonate even if the known frequency of the target device 30 deviates to some extent.

Further, in the vibration visualization device 10 according to the present embodiment, a scale 19, which is a scale indicating the relationship between the position of the magnet 14 and the natural frequency of the leaf spring 12, is provided on the second surface 12a2 of the leaf spring 12. there is This configuration makes it easy to adjust the natural frequency Fc of the leaf spring 12 by adjusting the position (height) of the magnet 14 on the second surface 12a2 of the leaf spring 12 based on the scale 19 .

In addition, the vibration visualization device 10 according to the present embodiment includes a housing 20 that accommodates its components. is fixed to the housing 20 so that the vibration of the target device 30 is transmitted to the base portion 11 through the housing 20 . The housing 20 is supported by the holder 25 so as to be rotatable about the first axis 251 and the second axis 252, and is held at an arbitrary rotational position. With this configuration, the direction of laser light and the optical magnification can be adjusted.

A device diagnostic device 1 according to the present embodiment is a device diagnostic device that diagnoses the state of the target device 30 from the vibration of the target device 30, and is provided with a vibration visualization device 10 and the vibration visualization device 10, and a laser and a screen 50 onto which laser light emitted from the light source 15 and reflected by the mirror 13 is projected. With this configuration, the vibration of the target device 30 is magnified as the amplitude of the vibration of the resonating leaf spring 12 (mechanical magnification), and the vibrating laser beam reflected by the mirror 13 fixed to the resonating leaf spring 12 is magnified as a locus 82 of a laser spot projected onto a screen 50 placed at a fixed distance outside the vibration visualization device 10 (optical magnification). As a result, minute vibrations can be reliably detected and visualized at a high magnification rate by mechanical and optical magnification due to resonance, so that highly reliable equipment diagnosis can be performed. Moreover, since the device diagnosis apparatus 1 does not require an electronic circuit for signal processing and has a simple structure consisting of a small number of parts, it is easy to manufacture and the manufacturing cost is low.

In the device diagnostic apparatus 1 according to the present embodiment, the screen 50 is provided with a scale 51 indicating the relationship between the amplitude 84 of the locus 82 of the spot of the laser beam and the effective value of the vibration velocity of the target device 30. . With this configuration, the effective value of the vibration velocity of the target device 30 can be measured from the amplitude 84 of the locus 82 of the laser beam spot displayed on the screen 50 .

Further, in the vibration visualization device 1 according to the present embodiment, the scale 51 associates the effective value of the vibration velocity as the vibration severity of the target device 30 with the state of the target device 30 . With this configuration, the effective value of the vibration velocity of the target device 30 and the state of the target device 30 can be easily grasped from the amplitude 84 of the trace 82 of the spot of the laser beam displayed on the screen 50 .

(Second embodiment)
Next, a vibration visualization device 10A according to a second embodiment of the present invention will be described with reference to the drawings.

The second embodiment differs from the first embodiment in that it uses a lens 90 and a plurality of leaf spring systems. The same reference numerals are assigned to the same components as in the first embodiment, and detailed description thereof will be omitted as appropriate.

FIG. 21 is a diagram showing a schematic configuration of a vibration visualization device 10A according to the second embodiment. As shown in FIG. 21, the vibration visualization device 10A includes a base portion 11A, a laser light source 15A, a lens 90 that converts the laser beam into plane light, and a plurality of leaf springs 12A ₁ , _{12A 2} , . (hereinafter also referred to as a plurality of leaf springs 12), _a plurality of mirrors 13A ₁ , _{13A 2} , . , 180A ₂ , . . . , 180A _n (hereinafter sometimes referred to as a plurality of dampers 180A). The plurality of dampers _180A includes copper plates 18A ₁ , . . . , 18A _n and magnets 14A ₁ , . The vibration visualization device 10A has a housing 20A that accommodates each component for dust prevention.

The housing 20A is installed in a diagnostic target device such as a rotating machine. Each of the plurality of leaf springs 12A has one end fixed to the base portion 11A and the other end serving as a free end. A mirror 13A is fixed to the first surface of each leaf spring 12A. A magnet 14A is attached to the second surface of each leaf spring 12A so that the position thereof can be adjusted. A copper plate 18A is attached to the base portion 11A so as to be spaced apart from the magnet 14A of each plate spring 12A. The leaf springs 12A ₁ , . . . , _{12A n} have different natural frequencies F _c1 , . The natural frequencies F _c1 , . . . , F _cn are set close to the frequency of the object.

FIG. 22 is a schematic diagram showing how a linear laser beam emitted from the laser light source 15A is converted into a plane laser beam by a cylindrical lens 90 made of, for example, glass or acrylic. The laser light source 15A and the lens 90 are fixed to the base portion 11A and simultaneously irradiate all the mirrors 13A with planar laser light. Planar laser light includes line laser light sent to each of the plurality of mirrors 13A. The line laser beams reflected by the plurality of mirrors 13 A pass through the transparent plate 22 provided in each opening 21 and project a laser spot trajectory onto the screen 50 .

The laser spot trajectory reflected from the mirror _13A on the leaf spring _12A with different natural frequencies and displayed on the screen 50 is the amplitude (velocity effective velocity value). Among them, the laser spot trajectory (frequency F _cmax ) with the largest amplitude is vibration close to the frequency of the object. Thereby, even if the vibration of the object 30 changes, the frequency and amplitude (vibration effective value) of the vibration of the object can be visually observed from the locus of the laser spot of the maximum amplitude.

With this configuration, even if the vibration frequency of the vibration of the target device fluctuates, the vibration visualization device 10A according to the second embodiment can achieve Since the leaf spring 12A resonates with the vibration of the target device, the vibration of the target device can be reliably detected, enlarged and visualized.

INDUSTRIAL APPLICABILITY As described above, the present invention has the effects of having a simple structure consisting of a small number of parts, being easy to manufacture at a low manufacturing cost, and having a high vibration amplification rate and high reliability. It is useful for vibration visualization devices, device diagnostic devices using the vibration visualization devices, vibration visualization methods, and device diagnostic methods in general.

Reference Signs List 1 equipment diagnostic device 10 vibration visualization device 11 base portion 12 leaf spring 12a spring body portion 12a1 first surface 12a2 second surface 12b spring mounting portion 12c fulcrum 12d end (one end)
12e end (other end)
REFERENCE SIGNS LIST 13 mirror 13a mirror reflection point 13b end face 14 magnet (weight)
14a arrow 15 laser light source 16 cable 17 laser light source mounting portion 18 non-magnetic metal plate member (copper plate)
18a Plate-like member body portion made of non-magnetic metal 18b Plate-like member fixing portion made of non-magnetic metal 18c Connecting portion 18d End (one end)
18e end (other end)
19 scale 20, 20A housing 20a housing body 20a1 surface 20a2, 20a3 outer surface 20b lid 21 opening 22 transparent plate 23 through hole 24 rotation center 25 holder 26 side plate 27 bottom plate 28, 29 adjustment screw 30, 30A object (Applicable device)
30B small drilling machine 40 ceiling 41 floor 50 screen 50a screen surface 51 scale 60 function generator 61 audio power amplifier 62 voice coil motor 63 damping sponge 64 vibration detector 65 vibration meter 66 test vibration generator 70 vibration direction
71 longitudinal direction 80 laser beam 82 laser spot trajectory 84 amplitude 90 lens 101, 102 adjustment direction 180 damper 251 first axis 252 second axis d spacing

Claims (14)

A vibration visualization device (10) for visualizing vibration of an object (30),
a base portion (11) installed on the object;
a leaf spring (12), one end of which is fixed to the base portion and the other end of which is free;
a mirror (13) fixed to the first surface of the leaf spring;
a laser light source (15) that is fixed to the base and emits laser light toward the mirror;
A vibration visualization device, wherein the leaf spring has a natural frequency (Fc) equal to a known vibration frequency (Fv) of the object. 2. The vibration visualization device of claim 1, further comprising a weight (14) adjustably mounted on the second surface of the leaf spring for adjusting the natural frequency of the leaf spring. It has a plate-like member (18) made of a non-magnetic metal, and one end (18d) of the plate-like member is arranged at a constant interval (d) from the weight. further comprising a damper (180) fixed to the part;
said weight comprises a magnet (14);
3. The vibration visualization device according to claim 2, characterized in that: wherein a scale (19) indicating the relationship between the position of the weight on the second surface of the leaf spring and the natural frequency of the leaf spring is provided on the second surface of the leaf spring; 4. The vibration visualization device according to claim 2 or 3. further comprising a housing (20) containing the components of the vibration visualization device, having an opening (21) through which the laser light reflected from the mirror passes;
5. The base portion is fixed to the housing such that the vibration of the object is transmitted to the base portion through the housing attached to the object. The vibration visualization device according to any one of . further comprising a holder (25) that rotatably supports the housing around two axes (251, 252) that are not parallel to each other and holds the housing at an arbitrary rotational position;
6. The vibration visualization device according to claim 1, wherein one of the two axes is parallel to the surface of the mirror and intersects one end surface of the mirror. A vibration visualization device (10A) for visualizing vibration of an object,
a base portion (11A) installed on the object;
a plurality of leaf springs (12A) each having one end fixed to the base portion and the other end being a free end;
a plurality of mirrors (13A) respectively fixed to the first surfaces of the plurality of leaf springs;
a laser light source (15A) that is fixed to the base and emits laser light;
a lens (90) fixed to the base and transforming laser light emitted by the laser light source into planar laser light including line laser light directed to all of the plurality of mirrors;
The vibration visualization device, wherein the plurality of leaf springs have different natural frequencies (Fc). A device diagnostic device (1) for diagnosing the state of a target device (30), which is the object, from vibration of the target device,
a vibration visualization device (10) according to any one of the preceding claims;
a screen (50) provided outside the vibration visualization device, on which the laser light emitted from the laser light source and reflected by the mirror is projected;
A device diagnostic device comprising: 9. The apparatus diagnostic apparatus according to claim 8, wherein the screen is provided with a scale indicating a relationship between an amplitude of the locus of the spot of the laser beam and an effective value of vibration velocity of the target apparatus. 10. The apparatus diagnostic apparatus according to claim 9, wherein the scale associates an effective value of vibration velocity as the vibration severity of the target apparatus with a state of the target apparatus. A vibration visualization method for visualizing the vibration of an object vibrating at a known frequency, comprising:
Adjusting the natural frequency of the leaf spring of the structure consisting of the leaf spring with the mirror attached and the weight to the known frequency of the object,
irradiating a laser beam toward the mirror fixed to a leaf spring resonating with the object;
irradiating the screen with the laser light reflected from the mirror to display the trajectory of the spot of the laser light;
A vibration visualization method comprising: vibrating the object at the known frequency;
measuring the vibration speed of the object with a vibration sensor;
Obtaining the relationship between the measured effective value of the vibration velocity and the amplitude of the trajectory of the spot of the laser light,
Applying a scale on the screen based on the obtained relationship;
12. The vibration visualization method of claim 11, further comprising: The step of obtaining the relationship is based on a pair of values consisting of the measured effective value of the vibration velocity and the amplitude value of the trajectory of the spot of the laser light, and the measured effective value of the vibration velocity; 13. The vibration visualization method according to claim 12, wherein the relationship between the amplitude of the trajectory of the spot of the laser light and the amplitude is acquired. A device diagnosis method for diagnosing the state of a target device (30), which is the object, from vibration of the target device,
including the vibration visualization method according to any one of claims 11 to 13,
A device diagnosis method, further comprising judging the state of the target device based on the amplitude of the trajectory of the spot of the laser beam displayed on the screen.

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