JP2005121614A - Deformation characteristic measuring apparatus for object - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a deformation characteristic measuring apparatus for an object, capable of eliminating errors in the measurement of displacement quantities as much as possible, while scaling down the apparatus as a whole. <P>SOLUTION: A path introducing air to the air nozzle 10 for making the optical axis of a laser displacement meter 11 for irradiating the point of action that jet wind from an air nozzle 10 acts upon an object to be measured, coincide with the point, and a path-guiding laser light source of the laser displacement meter 11 are set in common; a pneumatic unit 12, integrally supporting the laser displacement meter 11 and a pressure control valve 13, is provided; and the air nozzle unit 10 is mounted to the pneumatic unit 12. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an apparatus for measuring deformation characteristics of an object.

  It is known to apply an excitation force to an object and measure the mechanical impedance of the object. For example, to measure the viscosity, elasticity, or mass of an object, a periodic vibration force (input) with amplitude is applied to the object, and at the point of action or another point on the same object, By measuring the periodic response (output) of the generated acceleration, speed, and displacement, transfer characteristics between the excitation force and acceleration, speed, displacement, etc. can be obtained, and the deformation characteristics of the object can be known. This technique for measuring the mechanical impedance of an object is important for elucidating the mechanical behavior of a viscoelastic body having both elasticity and viscosity (plasticity) in terms of structure and for improving product performance. For example, for industrial materials, plastics, fibers, rubber, pulp, fats and oils, adhesives, ceramics, medicines, etc. are targeted. In addition, the field of fresh foods such as fruits, meat, and seafood, and the field of processed foods such as noodles In addition, medical fields such as a living body lumen such as a stomach wall or a living body surface such as skin or muscle are also targeted.

  Conventionally, the inventor has proposed a device for measuring the mechanical impedance of an object as described above in Japanese Patent Application No. 2002-329145. This consists of an air nozzle that injects pressurized air continuously or in pulses to the object to be measured and non-contactly vibrates, and pressure control for changing the amplitude, vibration frequency, or duty ratio of the pressurized air. A valve and a vibration measurement sensor for measuring at least one of acceleration, velocity, and displacement generated by the excitation force applied to the object to be measured, and further, the excitation force from the air nozzle and the object to be measured are measured. An arithmetic / display device is provided that calculates the deformation characteristics of an object from the transmission characteristics between at least one of acceleration, velocity, and displacement from the measurement object.

  Thereby, since pressurized air is jetted continuously or in a pulse shape to the object to be measured, it is possible to uniformly apply pressure regardless of the shape of the object to be measured, Deformation characteristics can be measured for any object to be measured. In addition, since the excitation force is compressed air with compressibility, the impact from the object to be measured is mitigated, and since it is non-contact with the object to be measured, the deformation characteristics are measured hygienically and without being damaged. There is an action and effect to do.

  Further, the vibration measuring sensor captures a phenomenon in which the position of the reflection surface of the laser light irradiated to the object to be measured changes due to the vibration of the object to be measured by the position detection element as a phenomenon in which the optical axis of the reflected light changes. In other words, since a laser displacement meter is used, there is an effect that the vibration state is hardly affected by the reflectance of the surface of the object to be measured and the vibration state is grasped with high accuracy without contact.

  However, in the above conventional apparatus (see FIG. 12), the air nozzle 100 for injecting pressurized air to the object to be measured and the laser displacement meter 110 are provided separately, so that the entire measuring apparatus becomes large. There was a problem. Further, when the pressurized air 100A is jetted from the air nozzle 100 to the object to be measured 105A continuously or in a pulsed manner, the object to be measured 105A (broken line) is pressed in a non-contact state and is in the state of reference numeral 105 (solid line). Become. The object to be measured is vibrated by repeating the state of reference numeral 105A and the state of reference numeral 105, and the deformation characteristics are measured. At this time, since the air nozzle 100 and the laser displacement meter 110 are provided separately, even if the focal point of the laser displacement meter is focused on the action point F1 of the air nozzle 100 before the blast, the air after the blast is air. There is a problem that the operating point F2 of the nozzle 100 and the focal point F3 of the laser displacement meter are shifted, and the measurement error of the displacement amount becomes large. This measurement error of the displacement amount is noticeable when the object to be measured is a soft material.

  In view of the above problems, an object of the present invention is to provide an apparatus for measuring deformation characteristics of an object, which can reduce the entire apparatus and can minimize a measurement error of a displacement amount.

  In order to solve the above-described problems, the present invention provides an air nozzle that injects pressurized air continuously or in a pulsed manner on an object to be measured and vibrates in a non-contact manner, and an amplitude, vibration frequency, or duty ratio of the pressurized air. A pressure control valve for changing, and a laser displacement meter for measuring a displacement caused by an excitation force applied to the object to be measured, and further, an excitation force from the air nozzle and a displacement from the object to be measured. An object deformation characteristic measuring device comprising a calculation / display device for calculating the deformation characteristic of an object from the transfer characteristic between the operating point where the blast from the air nozzle acts on the object to be measured, and A path for guiding air to the air nozzle and a path for guiding the laser light source of the laser displacement meter are made common to match the optical axis of the laser displacement meter that irradiates the working point, and the laser displacement meter And said Provided pneumatic unit supporting integrally the force control valve, attaching said air nozzle to the air pressure unit, took technical means of.

  The air nozzle may be detachable from the pneumatic unit.

  Furthermore, it is preferable to provide a cover body surrounding the air nozzle at the lower part of the pneumatic unit.

  According to the present invention, the path for guiding air to the air nozzle so that the action point at which the blast from the air nozzle acts on the object to be measured coincides with the optical axis of the laser displacement meter applied to the action point. And a path for guiding the laser light source of the laser displacement meter, and a pneumatic unit that integrally supports the laser displacement meter and the pressure control valve are provided, and the air nozzle is provided in the pneumatic unit. Since it is attached, air is blown to the object to be measured from the air nozzle through the air guide path of the pneumatic unit, and at the same time, the laser light source of the laser displacement meter passes through the same path to the air nozzle. To the object to be measured. That is, it is possible to minimize the measurement error of the displacement by matching the action point of the blast that acts on the object to be measured from the air nozzle and the focal point of the laser light source of the laser displacement meter that irradiates the action point. Moreover, since the laser displacement meter and the pressure control valve are integrally supported by the pneumatic unit, the entire apparatus can be reduced.

  Further, since the air nozzle can be attached to and detached from the pneumatic unit, an optimum air nozzle can be selected according to the object to be measured.

  In addition, since the lower part of the pneumatic unit is provided with a cover body that surrounds the air nozzle, the influence of the external atmosphere can be suppressed to prevent the blast air from spreading and turbulent flow.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing a device configuration of an apparatus for measuring deformation characteristics of an object. In FIG. 1, reference numeral 1 denotes a viscoelastic body to be measured. A stainless dish 4 is placed on a sample table 3 on a table 2, and a 5 mm thick sponge is placed on the upper surface of the dish 4. The film 5 is stretched. The viscoelastic body 1 has an air pillow shape in which air 6 is filled in a sponge-like film, and the flexibility is maintained.

  On the side of the viscoelastic body 1, an assembly type iron stand 9 composed of a leg portion 7 and an arm portion 8 is erected, and pressurized air is directed toward the viscoelastic body 1 at the tip of the arm portion 8. A nozzle 10 for injection and a laser displacement meter 11 are integrally supported. The bottom surface of the laser displacement meter 11 is provided with a light emitting unit 11a that emits a laser light source, and a light receiving unit 11b that irradiates the object to be measured with the laser light source from the light emitting unit 11a and receives the reflected light. And in order to make the action point where the blast blown from the nozzle 10 acts on the object to be measured coincide with the optical axis of the laser displacement meter 11 that irradiates this action point, between the nozzle 10 and the laser displacement meter 11. An air pressure unit 12 to be described later is provided. The distance between the nozzle 10 and the viscoelastic body 1 may be set to a distance to which air pressure is applied as much as possible. For example, the distance between the tip of the nozzle 10 and the surface of the viscoelastic body 1 is set to 5 mm. The

  A device for sending air is connected to the pneumatic unit 12. That is, a solenoid valve 13 serving as a main valve and a joint 14 are connected to the pneumatic unit 12, and an air regulator 16 (pressure adjusting valve) for controlling the air pressure from the joint 14 via an air hose 15. Or a pressure reducing valve) and an air compressor 17 serving as an air source. Then, when the pressure increases without air flowing to the outlet side, the air regulator 16 performs an operation (relief) of releasing the incoming air to the atmosphere to release the air, thereby controlling the air pressure.

  The electromagnetic valve 13 serving as the main valve is pressurized and held with air from the compressor 17, and the electromagnetic valve 13 is driven to open and close via a cable 19 from the personal computer 18 so that the air can be ejected. And pressurized air is injected. The electromagnetic valve 13 communicates with the nozzle 10 via the air flow path of the pneumatic unit 12. The laser displacement meter 11 is connected to the personal computer 18 via the cable 20 in order to measure the displacement of the working point of the object to be measured.

  FIG. 2 is a schematic diagram showing the measurement principle of the laser displacement meter 11 shown in FIG. In other words, the laser displacement meter 11 irradiates the surface of the film 5 with the beam light K emitted from the laser light source 21 through the light emitting unit 11 a through the pneumatic unit 12 and the nozzle 10, and reflects the light reflected on the surface of the film 5. The position detection element 22 detects the emission direction via the light receiving unit 11b. When the surface of the film 5 is displaced, the reflection direction of the beam light K by the surface is changed, and the light receiving position on the position detecting element 22 is changed. Therefore, the displacement sensor main circuit 23 detects this change in the light receiving position to detect the film 5. Can be measured.

  A pneumatic unit 12 is provided between the laser displacement meter 11 and the nozzle 10. The pneumatic unit 12 serves to make the focal point of the beam light K emitted from the laser light source 21 coincide with the point of action of the blast acting on the object to be measured. That is, with reference to FIGS. 3 to 5, the pneumatic unit 12 is provided with a female-threaded air supply path 24 for screwing the joint 14 in the horizontal direction, and the end of the female-threaded air supply path 24. An electromagnetic valve supply path 25 for sending air to the electromagnetic valve 13 is connected upward.

  As shown in FIG. 6, the internal configuration of the solenoid valve 13 includes an air cylinder 35 to which an air inlet port 30 and an air outlet port 31 are connected, a valve body 32 that slides in the air cylinder 35, and an air inlet port 30. A valve seat 33 that opens and closes the cylinder inlet side 36, a spring 34 that constantly presses the valve element 32, a solenoid device 37 that opens the valve seat 33 on the cylinder inlet side 36, and a spring side 35A of the air cylinder 35 And a back pressure port 38 for making the pressure of the air inlet port 30 the same. As a result, when no voltage is applied to the solenoid device 37, the valve element 32 is pressed by the spring 34 and the back pressure port 38 so that the valve seat 33 contacts the cylinder inlet side 36 and air does not leak, but the solenoid device 37 When a voltage is applied to the solenoid valve 37, the solenoid device 37 is excited, the valve body 32 moves in the solenoid direction (the chain line in FIG. 6), and the cylinder inlet side 36 is opened, whereby the air cylinder 35 is opened from the air inlet port 30. Then, the pressurized air is injected into the air outlet port 31 through the cylinder outlet side 40 (the arrow of the one-dot chain line in FIG. 6).

  The pneumatic unit 12 will be described with reference to FIGS. 3 to 5 again. The pneumatic unit 12 is provided with a solenoid valve discharge passage 26 for inducing a jet from the solenoid valve 13 downward ( 3 and 4), a horizontal relay path 27 is connected to the end of the solenoid valve discharge path 26, and a vertical relay path 28 that guides air from the horizontal relay path 27 to the nozzle 10. At the upper end of the vertical relay path 28, the light emitting part 11 a of the laser displacement meter 11 is faced, and the laser light source 21 is arranged to be guided into the vertical relay path 28. That is, the upper side of the vertical relay path 28 drilled in the pneumatic unit 12 is cut into a concave shape, and the displacement meter mounting surface 41 for mounting the laser displacement meter is provided. Then, the light emitting portion 11a of the laser displacement meter 11 is made to face the vertical relay path 28, and the fixing holder 42 is put on the laser displacement meter 11, and fixing screws 43, 43 are screwed to the pneumatic unit 12 to be fixed. . In order to guide the laser light source 21 into the vertical relay path 28, the pneumatic unit 12 is provided with adjustment holes 44, 44 for the female screw (FIGS. 3 and 5), and by adjusting the fastening of the female screw. Subtle position adjustment between the pneumatic unit 12 and the laser displacement meter 11 becomes possible. Reference numerals 45 and 45 are fixing screws for attaching the electromagnetic valve 13 to the pneumatic unit.

  A nozzle 10 for blast is provided at the lower end of the vertical relay path 28. The nozzle 10 is preferably threaded so that it can be attached to and detached from the pneumatic unit 12, and the tip nozzle length is formed to be about 13 mm so as to prevent the blast air from spreading and turbulent flow. The nozzle 10 may have an inner diameter of 1 mm, 2 mm, or 3 mm as appropriate depending on the object to be measured. The laser light source 21 has a spot diameter of 30 μm. May pass through the approximate center of the inner diameter of the nozzle 10 so that the displacement can be measured. An acrylic cover body 39 surrounding the nozzle 10 may be provided below the pneumatic unit so that the blast air does not spread or turbulent flow due to the external atmosphere (see FIG. 4).

  Next, the operation of the above configuration will be described. When the compressor 17 is activated to pressurize the air and adjusted to a predetermined pressure by the air regulator 16, the air hose 15, the joint 14, and the pneumatic unit 12 are filled with pressurized air.

  In the pneumatic unit 12, the air supply path 24 with a female thread and the solenoid valve supply path 25 are filled with pressurized air. When the solenoid valve 13 is driven to open and close in this state, pulsed air is injected from the nozzle 10. Is done. At this time, the displacement of the depression (concave portion) of the object to be measured is measured with a laser displacement meter. In order to inject pressurized air in a pulse shape, the solenoid valve 13 may be continuously turned on / off, and the period of the pulse can be changed by changing a timer or the like. In addition, the amplitude can be changed to change the pressure of the pressurized air. Furthermore, the duty ratio can be arbitrarily changed.

  When the electromagnetic valve 13 is driven to open and close, a voltage is applied to the solenoid device 37 according to a command from the personal computer 18. When a voltage is applied to the solenoid device 37, the valve element 32 moves in the solenoid direction by excitation, and the cylinder inlet side 36 is opened, so that the air outlet port 31 is pressurized from the air inlet port 30 through the air cylinder 35. Air is injected.

  The blast from the air outlet port 31 flows into the pneumatic unit 12 again. That is, the object to be measured is jetted from the nozzle 10 through the electromagnetic valve discharge path 26, the horizontal relay path 27, and the vertical relay path 28 of the pneumatic unit 12. Simultaneously with this blast, the laser light source 21 of the laser displacement meter 11 is guided into the vertical relay path 28 and is irradiated from the nozzle 10 onto the object to be measured. That is, the point of action of the blast that acts on the object to be measured from the nozzle 10 and the focal point of the laser light source 21 of the laser displacement meter 11 that irradiates the point of action coincide with each other, and it is possible to minimize the measurement error of the displacement. Become.

  A conventional measuring device (FIG. 12) in which the air nozzle 100 and the laser displacement meter 110 are provided separately, and a measuring device in which the air nozzle 10 and the laser displacement meter 11 are integrated via the pneumatic unit 12 of the present invention. (FIGS. 3 to 5). As a test material, a 5 mm thick sponge-like film was stretched on the upper surface of a stainless steel dish-like container, and a blast was applied stepwise from an air nozzle (see FIG. 7). Displacement was measured. When 10 patterns of air pressure were applied and the conventional apparatus was compared with the present invention (see FIG. 8), it was found that there was a measurement error of about 1 mm. As a result, if the measuring apparatus of the present invention is used, the overall configuration can be reduced, the action point of the blast acting on the object to be measured from the nozzle 10, and the laser displacement applied to the action point. The focus of the laser light source 21 of the total 11 coincided, and it became possible to eliminate the measurement error of the displacement amount as much as possible.

  As a test material, konjac, cherry tomato, and kiwi were used, and impedance measurement was performed using the measuring apparatus of the present invention. Displacement response was measured by applying a jet of air pressure 0.2 (MPa) and time 200 (msec) from the air nozzle 10 to each test material. The mass m, the viscosity c, and the elastic modulus k were calculated by the personal computer 18 assuming that the test material was the model shown in FIG. 10 and 11 show the results of impedance measurement for each of konjac, cherry tomato, and kiwi, and it is possible to identify what the object to be measured is by estimating the hardness.

  The present invention measures the hardness of plastics, fibers, rubber, pulp, fats and oils, adhesives, ceramics, chemicals, etc. if it is an industrial material, and if it is a fresh food, the hardness of fruits, meat, seafood, etc. In the case of measurement and processed foods, the hardness of noodles, processed cooked rice, retort foods, etc., and in the medical field, the hardness of living body cavities such as the stomach wall or the body surface such as skin and muscle Applicable to.

It is the schematic which shows the apparatus structure of the measuring apparatus of this invention. It is the schematic which shows the measurement principle of the laser displacement meter shown in FIG. It is an enlarged front view of a measuring device. It is a side view of the measuring device seen from the arrow A direction of FIG. It is a top view of the measuring device seen from the arrow B direction of FIG. It is a schematic longitudinal cross-sectional view which shows the internal structure of a solenoid valve. It is the measurement displacement data of the blast used for Example 1. FIG. It is the figure which applied the air pressure of 10 patterns and compared the conventional apparatus and this invention. It is a model for impedance measurement. It is the result of having performed impedance measurement about each of konjac, cherry tomato, and kiwi. It is the result of having compared mass m, viscosity c, and elastic modulus k. It is the schematic which shows the conventional measuring apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Viscoelastic body 2 Table 3 Sample stand 4 Dish container 5 Film 6 Air 7 Leg part 8 Arm part 9 Iron stand 10 Nozzle 11 Laser displacement meter 11a Light emission part 11b Light reception part 12 Pneumatic unit 13 Electromagnetic valve 14 Joint 15 Air hose 16 Air regulator 17 Air compressor 18 Personal computer 19 Cable 20 Cable 21 Laser light source 22 Position detection element 23 Displacement sensor main circuit 24 Female supply air supply path 25 Solenoid valve supply path 26 Solenoid valve discharge path 27 Horizontal relay path 28 Vertical relay path 30 Air inlet port 31 Air outlet port 32 Valve body 33 Valve seat 34 Spring 35 Air cylinder 36 Cylinder inlet side 37 Solenoid device 38 Back pressure port 39 Cover body 40 Cylinder outlet side 41 Displacement gauge mounting surface 42 Fixing holder 43 Fixing screw 44 For adjustment Hole 45 solid Constant screw

Claims (3)

An air nozzle for continuously or pulsedly injecting pressurized air to the object to be measured and oscillating in a non-contact manner; a pressure control valve for changing the amplitude, vibration frequency or duty ratio of the pressurized air; A laser displacement meter that measures the displacement caused by the excitation force applied to the object to be measured, and further, from the transfer characteristic between the excitation force from the air nozzle and the displacement from the object to be measured, the deformation of the object An apparatus for measuring deformation characteristics of an object having a calculation / display device for calculating characteristics,
A path for guiding air to the air nozzle and the laser displacement so that the action point at which the blast from the air nozzle acts on the object to be measured and the optical axis of the laser displacement meter irradiated to the action point A common path for guiding the laser light source of the meter, a pneumatic unit that integrally supports the laser displacement meter and the pressure control valve is provided, and the air nozzle is attached to the pneumatic unit. An apparatus for measuring deformation characteristics of an object.   The apparatus for measuring deformation characteristics of an object according to claim 1, wherein the air nozzle is attachable to and detachable from the pneumatic unit. The apparatus for measuring deformation characteristics of an object according to claim 1 or 2, further comprising a cover body surrounding the air nozzle at a lower portion of the pneumatic unit.

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