JP2004301695A - Hardness measuring instrument for vegetables and fruits equipped with pressure adjusting mechanism and method for measuring hardness of vegetables and fruits - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hardness measuring instrument for vegetables and fruits equipped with a pressure adjusting mechanism capable of performing measurement large in dynamic range and imparting no damage to vegetables and fruits under the pressure which corresponds to the kind of vegetables and fruits, that is, the kind of soft-hard vegetables and fruits, being the definite contact pressure corresponding to the kind of vegetables and fruits, and a hardness measuring method using it. <P>SOLUTION: A sensor unit case equipped with an elastic member having a predetermined elastic constant corresponding to the kind of vegetables and fruits is exchanged with respect to a hardness measuring instrument main body to measure the hardness of vegetables and fruits under the predetermined contact pressure corresponding to the kind of vegetables and fruits. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a vegetable and vegetable hardness measuring device provided with a pressure adjusting mechanism for non-destructively measuring the hardness of fruits and vegetables such as fruits and vegetables, and to a vegetable and vegetable hardness measuring method.
[0002]
[Prior art]
Conventionally, in fruits and vegetables such as vegetables, for example, by measuring the hardness of the pulp such as apples, the hardness of the rind such as orange and grapefruit, the degree of floating skin such as mandarin, the internal quality of fruits and vegetables, 2. Description of the Related Art Quality such as whether or not it can be stored and transported is measured.
[0003]
Conventionally, as a method for measuring the hardness of such fruits and vegetables, a load cell is pressed against the fruits and vegetables to measure the spring pressure when the surface of the fruits and vegetables is broken, and thereby the hardness of the fruits and vegetables is measured. Is used.
[0004]
[Problems to be solved by the invention]
However, such a spring-type hardness measuring device destroys the surface of fruits and vegetables, so that in a vegetable field, the fruits and vegetables whose surface has been destroyed for measurement must be discarded. Is a great deal of damage when converted to years.
By the way, conventionally, Patent Document 1 discloses a method of measuring hardness of an object to be measured such as rubber, resin, food, and food, and a method of measuring hardness using a living tissue such as a human skin or an organ as an object to be measured. A hardness measuring device using a detection circuit has been proposed.
[0005]
As shown in FIG. 11, the hardness measuring device 100 of Patent Document 1 includes a contact 105, a vibrator 103, a self-excited oscillation circuit 111, and a gain change correction circuit 113. Then, the self-excited oscillation circuit 111 feeds back the vibration information of the vibrator 103 to bring it into a resonance state. Also, a gain change correction circuit 113 is provided in the self-excited oscillation circuit 111, and the gain change correction circuit 113 has a center frequency different from the center frequency of the self-excited oscillation circuit 111, and the gain changes with respect to a change in frequency. , Thereby measuring the hardness of the object to be measured by a change in frequency.
[0006]
However, when the hardness measuring device 100 of Patent Document 1 configured as described above is used as it is when measuring the hardness of fruits and vegetables, the fruits and vegetables are relatively soft. Depending on the pressing pressure, the surface of fruits and vegetables may be destroyed.
Depending on the type of fruits and vegetables, for example, between fruits and vegetables with relatively high hardness such as apples and fruits and vegetables with relatively low hardness such as peaches, the contact area between the fruits and vegetables and the contactor is changed by the load. Therefore, the energy transfer efficiency changes, the gain change amount changes, and accurate hardness measurement becomes difficult.
[0007]
In view of such a situation, the present invention provides a pressure-sensitive vegetable / equipment having a pressure adjustment mechanism capable of performing an accurate hardness measurement according to the type of fruits / vegetables without breaking the fruits / vegetables as in the related art. An object of the present invention is to provide a hardness measuring device and a method for measuring the hardness of fruits and vegetables.
Further, the present invention provides a measurement that has a large dynamic range and does not damage fruits and vegetables at a pressure corresponding to the type of fruits and vegetables, that is, soft to hard, according to the type of fruits and vegetables. To provide a hardness measuring device and a hardness measuring method for fruits and vegetables provided with a pressure adjusting mechanism capable of performing each with a constant contact pressure.
[0008]
[Patent Document 1]
Japanese Patent No. 3151153 (especially, paragraphs [0062] to [0065], see FIG. 1)
[0009]
[Means for Solving the Problems]
The present invention has been made in order to achieve the above-described problems and objects in the prior art, and a hardness measuring apparatus for fruits and vegetables having a pressure adjusting mechanism of the present invention is capable of contacting fruits and vegetables. With the child,
A vibrator for vibrating the contact,
A self-excited oscillation circuit that returns the vibration information of the vibrator to a resonance state in a state where the contact is in contact with fruits and vegetables,
A vegetable and vegetable hardness measuring device that measures the hardness of fruits and vegetables based on a change in vibration of a vibrator that has come into contact with the fruits and vegetables via a contactor, based on frequency change information from the self-excited oscillation circuit.
In a state where the contact and the vibrator are urged so that the contact protrudes from an opening at the tip end of the hardness device main body through an elastic member having a predetermined elastic constant according to the type of fruits and vegetables. , Detachably attached to the hardness measuring device body,
Thereby, the hardness of the fruits and vegetables is measured at a predetermined contact pressure according to the type of the fruits and vegetables by replacing the elastic member having the predetermined elastic constant according to the type of the fruits and vegetables with the hardness measuring device main body. It is characterized by being configured to be able to.
[0010]
Further, the method for measuring the hardness of fruits and vegetables of the present invention is characterized in that, in a state where the contact is in contact with the fruits and vegetables, the vibration information of the vibrator that vibrates the contact is fed back via a self-excited oscillation circuit to the resonance state. Then
A method for measuring the hardness of fruits and vegetables, which measures the hardness of fruits and vegetables, based on a change in vibration of a vibrator in contact with the fruits and vegetables via a contactor, based on frequency change information from the self-excited oscillation circuit,
In a state where the contact and the vibrator are urged so that the contact protrudes from an opening at the tip end of the hardness device main body through an elastic member having a predetermined elastic constant according to the type of fruits and vegetables. , Detachably attached to the hardness measuring device body,
Thereby, the hardness of the fruits and vegetables is measured at a predetermined contact pressure according to the type of the fruits and vegetables by replacing the elastic member having the predetermined elastic constant according to the type of the fruits and vegetables with the hardness measuring device main body. It is characterized by doing.
[0011]
By configuring in this manner, depending on the type of fruits and vegetables, for example, in relatively hard fruits and vegetables such as apples, by using an elastic member having a relatively high elastic constant, conversely, peaches and the like For fruits and vegetables having relatively low hardness, the use of an elastic member having a relatively low elastic constant causes the fruits and vegetables to come into contact with the contact at a constant contact pressure corresponding to the type of the fruits and vegetables.
[0012]
Therefore, the contact area is constant, the energy transfer efficiency is constant, and as a result, accurate frequency change information can be obtained, and the hardness of fruits and vegetables can be accurately measured.
Also, since the fruits and vegetables come into contact with the contact at a constant contact pressure according to the type of fruits and vegetables, that is, the types of soft to hard fruits and vegetables, the hardness of the fruits and vegetables is measured without damaging the fruits and vegetables. It is possible to do.
[0013]
In addition, in this case, it is only necessary to replace the elastic member having a predetermined elastic constant according to the type of fruits and vegetables with the hardness measuring device main body. By simply preparing an elastic member having an elastic constant, the hardness of all kinds of fruits and vegetables can be measured, which is extremely convenient.
Further, the hardness measuring device for fruits and vegetables provided with the pressure adjusting mechanism of the present invention, a contactor that comes into contact with fruits and vegetables,
A vibrator for vibrating the contact,
A self-excited oscillation circuit that returns the vibration information of the vibrator to a resonance state in a state where the contact is in contact with fruits and vegetables,
A vegetable and vegetable hardness measuring device that measures the hardness of fruits and vegetables based on a change in vibration of a vibrator that has come into contact with the fruits and vegetables via a contactor, based on frequency change information from the self-excited oscillation circuit.
Forming a sensor body from the contact and the vibrator,
The sensor body is housed in the sensor unit case in a state where the contact body is urged through an elastic member having a predetermined elastic constant so as to protrude from the distal end opening of the sensor unit case,
The sensor unit case is detachably attached to the hardness measuring device main body so that the contact protrudes from a distal end opening of the hardness device main body,
Thereby, by replacing the sensor unit case provided with an elastic member having a predetermined elastic constant according to the type of fruits and vegetables with respect to the hardness measuring device main body, at a predetermined contact pressure according to the type of fruits and vegetables. It is characterized in that the hardness of fruits and vegetables can be measured.
[0014]
Further, the method for measuring the hardness of fruits and vegetables of the present invention is characterized in that, in a state where the contact is in contact with the fruits and vegetables, the vibration information of the vibrator that vibrates the contact is fed back via a self-excited oscillation circuit to the resonance state. Then
A method for measuring the hardness of fruits and vegetables, which measures the hardness of fruits and vegetables, based on a change in vibration of a vibrator in contact with the fruits and vegetables via a contactor, based on frequency change information from the self-excited oscillation circuit,
Forming a sensor body from the contact and the vibrator,
The sensor body is housed in the sensor unit case in a state where the contact body is urged through an elastic member having a predetermined elastic constant so as to protrude from the distal end opening of the sensor unit case,
The sensor unit case is detachably attached to the hardness measuring device main body so that the contact protrudes from a distal end opening of the hardness device main body,
Thereby, by replacing the sensor unit case provided with an elastic member having a predetermined elastic constant according to the type of fruits and vegetables with respect to the hardness measuring device main body, at a predetermined contact pressure according to the type of fruits and vegetables. It is characterized by measuring the hardness of fruits and vegetables.
[0015]
By configuring in this manner, depending on the type of fruits and vegetables, for example, in relatively hard fruits and vegetables such as apples, by using an elastic member having a relatively high elastic constant, conversely, peaches and the like For fruits and vegetables having relatively low hardness, the use of an elastic member having a relatively low elastic constant causes the fruits and vegetables to come into contact with the contact at a constant contact pressure corresponding to the type of the fruits and vegetables.
[0016]
Therefore, the contact area is constant, the energy transfer efficiency is constant, and as a result, accurate frequency change information can be obtained, and the hardness of fruits and vegetables can be accurately measured.
Also, since the fruits and vegetables come into contact with the contact at a constant contact pressure according to the type of fruits and vegetables, that is, the types of soft to hard fruits and vegetables, the hardness of the fruits and vegetables is measured without damaging the fruits and vegetables. It is possible to do.
[0017]
Moreover, in this case, it is only necessary to replace the sensor unit case provided with the elastic member having a predetermined elastic constant according to the type of fruits and vegetables with respect to the hardness measuring device main body, so that the replacement operation can be easily performed, and By simply preparing a sensor unit case corresponding to the type of fruits and vegetables, the hardness of all types of fruits and vegetables can be measured, which is extremely convenient.
[0018]
Further, the hardness measuring device for fruits and vegetables provided with the pressure adjusting mechanism of the present invention, a contactor that comes into contact with fruits and vegetables,
A vibrator for vibrating the contact,
A self-excited oscillation circuit that returns the vibration information of the vibrator to a resonance state in a state where the contact is in contact with fruits and vegetables,
A vegetable and vegetable hardness measuring device that measures the hardness of fruits and vegetables based on a change in vibration of a vibrator that has come into contact with the fruits and vegetables via a contactor, based on frequency change information from the self-excited oscillation circuit.
The contactor and the vibrator, through an elastic member, from the tip opening of the hardness device main body, in a state where the contactor is urged to protrude, and mounted on the hardness measurement device main body,
In accordance with the type of fruits and vegetables, comprises an elastic pressure adjusting mechanism that controls the elastic pressure by adjusting the compression length of the elastic member,
The hardness of fruits and vegetables can be measured at a predetermined contact pressure by controlling the elastic pressure adjusting mechanism.
[0019]
Further, the method for measuring the hardness of fruits and vegetables of the present invention is characterized in that, in a state where the contact is in contact with the fruits and vegetables, the vibration information of the vibrator that vibrates the contact is fed back via a self-excited oscillation circuit to the resonance state. Then
A method for measuring the hardness of fruits and vegetables, which measures the hardness of fruits and vegetables, based on a change in vibration of a vibrator in contact with the fruits and vegetables via a contactor, based on frequency change information from the self-excited oscillation circuit,
The contactor and the vibrator are attached to the hardness measuring device main body via an elastic member, in a state where the contactors are urged to protrude from the distal end opening of the hardness device main body,
The hardness of the fruits and vegetables is measured at a predetermined contact pressure by controlling an elastic pressure adjusting mechanism that controls the elastic pressure by adjusting the compression length of the elastic member according to the type of fruits and vegetables.
[0020]
By configuring in this way, by controlling the elastic pressure adjusting mechanism and controlling the elastic pressure by adjusting the compression length of the elastic member in accordance with the type of fruits and vegetables, for example, a comparative example such as apples For fruits and vegetables with high hardness, the elastic pressure is relatively high, and conversely for fruits and vegetables with relatively low hardness such as peach, the elastic pressure is relatively low. At a certain contact pressure, the fruits and vegetables come into contact with the contact.
[0021]
Therefore, the contact area is constant, the energy transfer efficiency is constant, and as a result, accurate frequency change information can be obtained, and the hardness of fruits and vegetables can be accurately measured.
Also, since the fruits and vegetables come into contact with the contact at a constant contact pressure according to the type of fruits and vegetables, that is, the types of soft to hard fruits and vegetables, the hardness of the fruits and vegetables is measured without damaging the fruits and vegetables. It is possible to do.
[0022]
Moreover, in this case, it is only necessary to adjust the compression length of the elastic member and control the elastic pressure by controlling the elastic pressure adjusting mechanism according to the type of fruits and vegetables, so that the hardness measurement work is simple. It is very convenient to measure the hardness of all kinds of fruits and vegetables.
Furthermore, the present invention is characterized in that the tip of the contact is substantially spherical.
[0023]
Since the tip of the contact has a substantially spherical shape as described above, the contact area with the fruits and vegetables does not change, and it is possible to always perform a constant and accurate hardness measurement.
Further, in the present invention, the elastic member may be a spring member, and the elastic member may be one or more elastic members selected from silicone resin, epoxy resin, and rubber.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments (examples) of the present invention will be described in more detail with reference to the drawings. FIG. 1 is a schematic front view of an embodiment of the vegetable and vegetable hardness measuring apparatus of the present invention, FIG. 2 is a schematic sectional view of the vegetable and vegetable hardness measuring apparatus of FIG. 1, and FIG. FIG. 3B is an end view in the direction A of FIG. 3A, and FIG. 4 is a circuit configuration diagram of a filter circuit used in a gain change correction circuit. FIG. 5 is a frequency-gain-phase characteristic curve diagram illustrating the principle of the vegetable hardness measuring apparatus of the present invention.
[0025]
In FIG. 1, reference numeral 10 denotes a hardness measuring device 10 for fruits and vegetables of the present invention (hereinafter, simply referred to as “hardness measuring device”).
The hardness measuring device 10 is for measuring the hardness of fruits and vegetables A such as fruits and vegetables as shown in FIG. 1, and as shown in FIG. A piece-type hardness measuring device main body 12 is provided. The hardness measuring device main body 12 includes a gripping portion 14 that is held by a measurer with a hand, an operation display portion 16 formed on the distal end side of the gripping portion 14, and a contact portion formed on the distal end side of the operation display portion 16. And a child 18.
[0026]
The operation display section 16 and the contact 18 are covered by a detachable cap-shaped cover member 12a so that they can be protected when not in use.
As shown in FIG. 1, the operation display unit 16 displays operation buttons 20 such as a power button 20a for turning on / off the power, a setting button 20b for setting the type of fruits and vegetables, and the hardness of the fruits and vegetables. A display window 22 made of a liquid crystal display or the like is provided.
[0027]
On the other hand, a sensor unit 24 and a control unit 26 are disposed inside the hardness measuring device main body 12, as shown in FIGS.
As shown in FIG. 2, the sensor unit 24 includes a sensor unit case 28 that can be detachably mounted inside the sensor unit 24 of the hardness measuring device main body 12. A sensor holder 30 is slidably mounted on the sensor unit case 28 in the front-rear direction (in the left-right direction in FIG. 2).
[0028]
A sensor body 34 is mounted on the sensor holder 30. The sensor body 34 includes a plate-shaped vibrator 36, a detection element 38 formed on the surface of the base end of the vibrator 36, and a contact element mounted on the distal end of the vibrator 36 and having a substantially spherical tip. 18 is provided. The vibrator 36 is supported by the support 42 of the sensor holder 30.
[0029]
As such a vibrator, a laminated piezoelectric ceramic vibrator, an ultrasonic vibrator, or the like can be used, and is not particularly limited.
At this time, it is desirable that the contact area between the support portion 42 and the vibrator 36 is reduced, and the support portion 42 and the vibrator 36 are fixed at a node of a standing wave of vibration generated in the sensor body 34. It is desirable to be done.
[0030]
As shown in FIG. 2, the base end of the sensor holder 30 is branched into two branches, and slide guide members 44 are formed. These sliding guide members 44 are slidably guided in the opening 43 of the guide member 41 having a substantially U-shaped cross section fitted in the openings 48, 48 at the base end of the sensor unit case 28. It has become. Further, spring members 40, 40 having a predetermined spring constant are interposed between the guide members 41 on the outer periphery of the sliding guide members 44, 44.
[0031]
The spring members 40, 40 urge the contacts 18 so as to project from the distal end portion 50 of the sensor unit case 28 and the distal end opening 52 formed at the distal end of the hardness measuring device main body 12. At this time, the distal end portion 54 of the sensor holder 30 contacts the distal end portion 50 of the sensor unit case 28 so that the contact 18 does not protrude beyond a certain amount.
[0032]
Then, as shown in FIG. 2, the vibrator 36 of the sensor body 34 and the detecting element 38 are connected to the control unit 26.
That is, as shown in FIG. 2, the transducer 36 is connected to the gain change correction circuit 56 of the control unit 26, and the detection element 38 is connected to the amplifier circuit 58.
The vibrator 36, the detection element 38, and the amplifier circuit 58 form a self-excited oscillation circuit 60. In other words, a feedback loop is formed in which the vibration information of the vibrator 36 is extracted as an electric signal by the detection element 38, the electric signal is amplified by the amplifier circuit 58, and then fed back to the vibrator 36.
[0033]
The self-excited oscillation circuit 60 constitutes an electric oscillation system that returns the vibration information of the vibrator 36 to the vibrator 36 via the detection element 38 and the amplifying circuit 58 to bring the vibrator 36 into a resonance state. I have.
On the other hand, the vibrator 36 and the contact 18 constitute a mechanical vibration system for transmitting vibration information of the vibrator 36 to the fruits and vegetables A as the object to be measured via the contact 18.
[0034]
That is, the hardness measuring device 10 of the present invention constitutes a mechanical-electric vibration system in which a mechanical vibration system and an electric vibration system are combined.
The gain change correction circuit 56 provided in the control unit 26 has a function of changing the gain with respect to a change in frequency, such as a function of increasing the gain with respect to an increase in frequency.
[0035]
Further, the gain change correction circuit 56 has a phase transfer function of adjusting the input / output combined phase difference, which is the phase difference between the input phase and the output phase of the self-excited oscillation circuit 60, to zero and promoting feedback oscillation.
Accordingly, the gain change correction circuit 56 changes the frequency until the combined input / output phase difference becomes zero, and responds to the change in the frequency, for example, by increasing the gain change width with respect to the increase in the frequency. And a function of increasing a gain change.
[0036]
In this embodiment, a filter circuit having a frequency-gain characteristic in which the gain increases with a change in frequency is used as the gain change correction circuit 56.
FIG. 4 is a circuit configuration diagram of an exemplary filter circuit used in the gain change correction circuit 56.
This filter circuit includes resistance elements R11, R12, R13, R14, capacitance elements C11, C12, C13, C14, and an amplifier circuit AMP. In this embodiment, the resistance element R11 is set to 10KΩ, the resistance element R12 is set to 220Ω, the resistance element R13 is set to 420KΩ, and the resistance element R14 is set to 2.2KΩ.
[0037]
Further, power (12 V) is supplied to the amplifier circuit AMP from a power supply terminal V11. Further, a voltage (−12 V) is applied to the reference power supply terminal V12. In the figure, the sign Vin is a signal input terminal, and the sign Vout is a signal output terminal.
This filter circuit has the characteristics of a bandpass filter circuit. The input terminal Vin of the gain change correction circuit 56 is connected to the output terminal of the amplifier circuit 58, and the output terminal Vout is connected to the input terminal of the vibrator 36.
[0038]
Further, the control unit 26 includes a frequency measuring section 62 for measuring the oscillation frequency of the self-excited oscillation circuit 60, and a hardness measuring section for measuring the hardness of the fruits and vegetables A based on the frequency measured by the frequency measuring section 62. 64, a storage unit 66 for preliminarily storing the correlation between the frequency and the hardness, an input unit 68 for performing input such as an instruction input to the control unit 26, and a display unit 65 for displaying the measured frequency value or hardness. Have.
[0039]
The principle of the hardness measuring device 10 of the present invention configured as described above will be described below.
FIG. 5 is a frequency-gain-phase characteristic curve diagram showing respective frequency characteristics of the self-excited oscillation circuit 60 and the gain change correction circuit 56.
In FIG. 5, the horizontal axis indicates frequency, and the vertical axis indicates gain and phase.
[0040]
In the frequency-gain characteristic curve 56G of the gain change correction circuit 56, the gain increases as the frequency increases in the low frequency band, the gain becomes maximum in the center frequency f2 band, and the high frequency band Draw a mountain curve with decreasing gain.
A characteristic curve θ56 is a phase characteristic indicating an input / output phase difference of the gain change correction circuit 56. The characteristic curve MG is a frequency-gain characteristic curve of the self-excited oscillation circuit 60 excluding the gain change correction circuit 56.
[0041]
Although the frequency-gain characteristic curve MG differs in the center frequency f1, the frequency band, and the maximum value of the gain, it basically draws a peak curve like the frequency characteristic of the gain change correction circuit 56.
In this embodiment, as shown in the frequency-gain characteristic curves MG and 56G, the center frequency f1 of the self-excited oscillation circuit 60 indicated by the maximum gain value P1 and the center frequency indicated by the maximum gain value 56GP of the gain change correction circuit 56. The frequency f2 is set to a frequency band shifted intentionally.
[0042]
That is, for example, the center frequency f2 of the gain change correction circuit 56 is set to a high frequency band with respect to the center frequency f1 of the self-excited oscillation circuit 60 so that the gain increases as the hardness coefficient of the fruits and vegetables A increases. I have.
When the contact 18 of the hardness measuring device 10 is brought into contact with the fruits and vegetables A, the vibration mode of the vibrator 36 changes due to an increase in the mechanical impedance or acoustic impedance of the fruits and vegetables A, and the frequency characteristics of the mechanical electric vibration system are changed. Change. That is, the vibration information including the vibration frequency, gain, phase, and vibration amplitude of the mechanical / electric vibration system changes.
[0043]
That is, the frequency characteristic received by the detection element 38 changes according to the hardness of the fruits and vegetables A, and as a result, the frequency, gain, phase, and amplitude of the electric signal of the self-excited oscillation circuit 60 change. I do.
Therefore, the frequency of the self-excited oscillation circuit 60 changes (for example, increases) from the center frequency f1 of the self-excited oscillation circuit 60 to the resonance frequency f11 according to the hardness of the fruits and vegetables A.
[0044]
The maximum gain value of the frequency-gain characteristic curve MG of the self-excited oscillation circuit 60 changes from the maximum gain value P1 along the frequency-gain characteristic curve 56G of the gain change correction circuit 56, and rises from the maximum gain value P1. To change.
That is, the frequency-gain characteristic curve MG of the self-excited oscillation circuit 60 changes to the frequency-gain characteristic curve MG1, the maximum gain value P1 changes to the maximum gain value P11, and the gain G1 changes to the gain G11.
[0045]
As shown in FIG. 4, since the feedback loop of the self-excited oscillation circuit 60 is a circuit including a resistance element and a capacitance element, between the input phase θ1 and the output phase θ2 of the self-excited oscillation circuit 60, There always exists a phase difference Δθ.
On the other hand, the gain change correction circuit 56 has a phase transfer function, and adjusts the combined input / output phase difference θ11 of the feedback loop including the gain change correction circuit 56 to zero.
[0046]
Therefore, the frequency further changes and the gain further changes until the input / output combined phase difference θ11 reaches a stable point of feedback oscillation at which it becomes zero.
That is, the frequency-gain characteristic curve MG1 of the self-excited oscillation circuit 60 changes to the frequency-gain characteristic curve MG1, and the resonance frequency f11 changes to the resonance frequency f12. With the change to the resonance frequency f12, the maximum gain value P11 changes to the maximum gain value P12, and the gain G11 changes to the gain G12.
[0047]
That is, the center frequency f1 of the self-excited oscillation circuit 60 continuously changes, for example, increases to the resonance frequency f12 by the amount corresponding to the phase difference Δθ, and the gain G1 changes continuously to the gain G12, for example, To rise.
As a result, in the self-excited oscillation circuit 60, the frequency change Δf and the gain change ΔG are obtained. When the frequency change Δf1 and the gain change ΔG of the self-excited oscillation circuit 60 are obtained, the combined input / output phase difference θ11 becomes zero, and the self-excited oscillation circuit 60 performs feedback oscillation.
[0048]
In the hardness measuring device 10 according to this embodiment, the frequency change Δf before and after the contact of the contact 18 with the fruit and vegetable A is detected as hardness information according to the hardness of the fruit and vegetable A. And the hardness of fruits and vegetables A can be measured. Similarly, the hardness of the soft fruits and vegetables A can be measured by detecting the phase difference Δθ before and after contacting the fruits and vegetables A with the contact 18 as hardness information.
[0049]
That is, the hardness of the fruits and vegetables A is determined by inputting the information to the hardness measurement unit 64 of the control unit 26 and comparing the data with the data of the storage unit 66 in which the correlation between the frequency and the hardness is stored in advance. The section 65 displays data such as frequency and hardness.
Therefore, in the hardness measuring device 10 of the present invention, the gain can be increased in accordance with the respective changes of the frequency change Δf and the phase difference Δθ, that is, the gain change ΔG is obtained. Therefore, it is possible to obtain a detection voltage sufficient for determining the hardness of the fruits and vegetables A.
[0050]
By the way, in such a hardness measuring device 10 of the present invention, when the measurer grips the gripper 14 with his hand and presses the contact 18 at the tip thereof against the fruits and vegetables A, for example, an apple or the like is used. In the case of hard fruits and vegetables and soft fruits and vegetables such as peach, the contact area between the fruits and vegetables A and the contact 18 changes depending on the load. For this reason, the energy transfer efficiency changes, and the above-mentioned gain change amount ΔG changes, making it difficult to measure hardness accurately.
[0051]
Therefore, in the hardness measuring device 10 of this embodiment, as shown in FIG. 3, depending on the type of the fruits and vegetables A, that is, for example, hard fruits and vegetables such as apples and soft fruits and vegetables such as peaches In advance, a sensor unit case 28 in which a spring member 40 having a different spring constant is interposed is prepared in advance, and is selected according to the type of fruits and vegetables A to be measured. It can be detachably mounted inside the twelve sensor units 24. In FIG. 3, reference numeral 27 denotes a connector for electrical connection.
[0052]
The structure in which the sensor unit case 28 can be detachably attached to the inside of the sensor unit 24 of the hardness measuring device main body 12 is not particularly limited. 12, the sensor unit case 28 may be replaced after the cover is removed.
[0053]
With such a configuration, depending on the type of the fruits and vegetables A, for example, in the case of fruits and vegetables having relatively high hardness such as apples, by using the spring member 40 having a relatively high spring constant, conversely, For fruits and vegetables having relatively low hardness, the use of the spring member 40 having a relatively low spring constant causes the fruits and vegetables to come into contact with the contact at a constant contact pressure according to the type of the fruits and vegetables. .
[0054]
Therefore, the contact area between the contact 18 and the fruits and vegetables A is constant, the energy transfer efficiency is constant, and as a result, accurate frequency change information is obtained, and the hardness of the fruits and vegetables is accurately measured. It becomes possible.
Further, since the fruits and vegetables A come into contact with the contactor 18 at a constant contact pressure according to the type of fruits and vegetables, that is, the types of soft to hard fruits and vegetables, the hardness of the fruits and vegetables without damaging the fruits and vegetables. Can be measured.
[0055]
Moreover, in this case, it is only necessary to replace the sensor unit case 28 provided with the spring member 40 having a predetermined spring constant according to the type of fruits and vegetables with respect to the hardness measuring device main body 12, so that the replacement operation is easy. The hardness of all types of fruits and vegetables can be measured simply by preparing the sensor unit case 28 corresponding to the type of fruits and vegetables, which is extremely convenient.
[0056]
In the above embodiment, the sensor unit case 28 including the spring member 40 having a predetermined spring constant according to the type of fruits and vegetables is replaced with the hardness measuring device main body 12, but it is not shown. It is also possible to prepare a spring member 40 having a predetermined spring constant according to the type of fruits and vegetables, and replace it with the hardness measuring device main body 12.
[0057]
In this case, since only the spring member 40 needs to be replaced, the replacement operation can be easily performed, and the hardness of all types of fruits and vegetables is measured by simply preparing a spring member corresponding to the type of fruits and vegetables. It can be extremely convenient.
Further, in the above embodiment, the spring member 40 having a predetermined spring constant was used, but any elastic member having a predetermined elastic constant may be used, and is not particularly limited. Examples thereof include a silicone resin and an epoxy resin. And one or more elastic members selected from rubber (the same applies to the following embodiments).
[0058]
FIG. 6 is a schematic sectional view of another embodiment of the fruit and vegetable hardness measuring apparatus of the present invention.
The hardness measuring device 10 of this embodiment has basically the same configuration as that of the hardness measuring device 10 shown in FIGS. 1 to 3, and the same components are denoted by the same reference numerals, and details thereof will be described. Detailed description is omitted.
In the hardness measuring device 10 shown in FIGS. 1 to 3, the base end of the sensor holder 30 branches into two branches as shown in FIG. 2 to form sliding guide members 44, 44. The sliding guide member 44 is slidably guided in the opening 43 of the guide member 41 having a substantially U-shaped cross section fitted into the openings 48, 48 at the base end of the sensor unit case 28. However, in the hardness measuring device 10 of this embodiment, as shown in FIG. 6, a single sliding guide member 44 is formed at the center without branching the base end of the sensor holder 30 into two branches. The sensor unit case 28 is configured to be slidably guided in an opening 43 of a guide member 41 having a substantially U-shaped cross section fitted in an opening 48 at the center of the base end of the sensor unit case 28. .
[0059]
The hardness measuring device 10 of this embodiment can also provide the same operation and effects as those of the hardness measuring device 10 shown in FIGS.
FIG. 7 is a schematic sectional view of another embodiment of the fruit and vegetable hardness measuring apparatus of the present invention.
The hardness measuring device 10 of this embodiment has basically the same configuration as that of the hardness measuring device 10 shown in FIGS. 1 to 3, and the same components are denoted by the same reference numerals, and details thereof will be described. Detailed description is omitted.
[0060]
In the hardness measuring device 10 of this embodiment, the sensor unit case 28 is fixed to the hardness measuring device main body 12 so that the sensor unit case 28 and the spring member 40 cannot be replaced.
A spring pressure adjusting mechanism 70 that adjusts the compression length of the spring member 40 to control the spring pressure according to the type of the fruits and vegetables A is provided. By controlling the spring pressure adjusting mechanism 70, the hardness of the fruits and vegetables A can be measured at a predetermined contact pressure.
[0061]
That is, the spring pressure adjusting mechanism 70 slidably moves the outer circumferences of the sliding guide members 44, 44 into the openings 48, 48 at the base end of the sensor unit case 28, and moves the spring members 40, 40. A spring pressure adjusting member 72 for adjusting the compression length is provided.
The spring pressure adjusting member 72 is controlled by the control unit of the control unit 26 so that the spring pressure is stored in advance in the storage unit 66 in accordance with the type of the fruits and vegetables A input to the control unit 26 by the input unit 68. Under the control, it can be moved in the front-rear direction by a drive mechanism (not shown) such as a pulse motor or a servo motor. Instead of the driving mechanism, a scale may be provided in advance, and the scale may be manually adjusted according to the scale.
[0062]
The appropriate spring pressure (load) according to the kind of the fruits and vegetables A is set based on, for example, a graph as shown in FIG.
With this configuration, the compression length of the spring member 40 is adjusted by controlling the spring pressure adjusting mechanism 70 according to the type of the fruits and vegetables A, as shown by the arrow B in FIG. By controlling the spring pressure, for example, for relatively hard fruits and vegetables such as apples, the spring pressure is relatively high, and conversely for relatively hard fruits and vegetables such as peaches, the spring pressure is compared. By making the target lower, the fruits and vegetables A come into contact with the contact 18 at a constant contact pressure corresponding to the type of the fruits and vegetables A.
[0063]
Accordingly, the contact area between the fruits and vegetables A and the contact 18 is constant, the energy transfer efficiency is constant, and as a result, accurate frequency change information is obtained, and the hardness of the fruits and vegetables A is accurately measured. It is possible to do.
Further, since the fruits and vegetables A come into contact with the contact 18 at a constant contact pressure according to the type of the fruits and vegetables A, that is, the types of soft to hard fruits and vegetables, the fruits and vegetables A are not damaged. Can be measured.
[0064]
Moreover, in this case, it is only necessary to adjust the compression length of the spring member 40 and control the spring pressure by controlling the spring pressure adjusting mechanism 70 according to the type of fruits and vegetables, so that the hardness measurement operation is a simple operation. Thus, it is very convenient to measure the hardness of all kinds of fruits and vegetables.
FIG. 8 is a schematic cross-sectional view of another embodiment of the hardness measuring apparatus for fruits and vegetables of the present invention.
[0065]
The hardness measuring device 10 of this embodiment has basically the same configuration as the hardness measuring device 10 shown in FIG. 7, and the same components are denoted by the same reference numerals, and will not be described in detail. Omitted.
In the hardness measuring device 10 shown in FIG. 8, in the hardness measuring device 10 of the present embodiment, as shown in FIG. A dynamic guide member 44 is formed and slidably inserted into a central opening 48 at the base end of the sensor unit case 28. As a spring pressure adjusting mechanism 70, the sensor unit case 28 A spring pressure adjusting member 72 for adjusting the compression length of the spring members 40, 40 by slidably moving the outer periphery of the slide guide member 44 in the opening 48 at the base end.
[0066]
The hardness measuring device 10 of this embodiment can also provide the same operation and effect as the hardness measuring device 10 shown in FIG.
FIG. 9 is a schematic sectional view of another embodiment of the fruit and vegetable hardness measuring apparatus of the present invention.
The hardness measuring device 10 of this embodiment has basically the same configuration as that of the hardness measuring device 10 shown in FIGS. 1 to 3, and the same components are denoted by the same reference numerals, and details thereof will be described. Detailed description is omitted.
[0067]
In the hardness measuring apparatus 10 of this embodiment, a spring member 40 is interposed between both ends 31 of the base end of the sensor holder 30 and the flange 21 provided inside the sensor unit case 28.
The contact member 18 is urged by the spring member 40 so as to protrude from the distal end portion 50 of the sensor unit case 28 and the distal end opening 52 formed at the distal end of the hardness measuring device main body 12.
[0068]
The hardness measuring device 10 of this embodiment can also provide the same operation and effects as those of the hardness measuring device 10 shown in FIGS.
In the embodiment described above, for example, the center frequency f2 of the gain change correction circuit 56 is set higher than the center frequency f1 of the self-excited oscillation circuit 60 so that the gain increases as the hardness coefficient of the fruits and vegetables A increases. In contrast, the center frequency f2 of the gain change correction circuit 56 is lower than the center frequency f1 of the self-excited oscillation circuit 60 so that the gain decreases as the hardness coefficient of the fruits and vegetables A increases. It is also possible to set a frequency band.
[0069]
The preferred embodiment of the present invention has been described above. However, the present invention is not limited to this. For example, the gain change correction circuit 56 increases the gain with respect to a change in the frequency. It suffices to have a characteristic of increasing the voltage. For example, a low-pass filter circuit, a high-pass filter circuit, a notch filter circuit, an integration circuit, a differentiation circuit, a peaking amplification circuit, or the like is used in addition to the band-pass filter circuit in the above-described embodiment. Various changes can be made without departing from the purpose of the present invention.
[0070]
【The invention's effect】
According to the present invention, depending on the type of fruits and vegetables, for example, in relatively hard fruits and vegetables such as apples, by using an elastic member having a relatively high elastic constant, conversely, comparison of peaches and the like For fruits and vegetables having low target hardness, the use of an elastic member having a relatively low elastic constant causes the fruits and vegetables to come into contact with the contact at a constant contact pressure according to the type of the fruits and vegetables.
[0071]
Therefore, the contact area is constant, the energy transfer efficiency is constant, and as a result, accurate frequency change information can be obtained, and the hardness of fruits and vegetables can be accurately measured.
Also, since the fruits and vegetables come into contact with the contact at a constant contact pressure according to the type of fruits and vegetables, that is, the types of soft to hard fruits and vegetables, the hardness of the fruits and vegetables is measured without damaging the fruits and vegetables. It is possible to do.
[0072]
In addition, in this case, it is only necessary to replace the elastic member having a predetermined elastic constant according to the type of fruits and vegetables with the hardness measuring device main body. By simply preparing an elastic member having an elastic constant, the hardness of all kinds of fruits and vegetables can be measured, which is extremely convenient.
Further, according to the present invention, the sensor unit case provided with the elastic member having a predetermined elastic constant according to the type of fruits and vegetables only needs to be exchanged with the hardness measuring device main body, so that the exchange operation is easy. In addition to being able to measure, the hardness of all kinds of fruits and vegetables can be measured only by preparing a sensor unit case corresponding to the kind of fruits and vegetables, which is extremely convenient.
[0073]
Further, according to the present invention, the elastic pressure is controlled by adjusting the compression length of the elastic member by controlling the elastic pressure adjusting mechanism in accordance with the type of fruits and vegetables, for example, to control the relative pressure of an apple or the like. For fruits and vegetables with high hardness, the elastic pressure is relatively high, and conversely for fruits and vegetables with relatively low hardness such as peach, the elastic pressure is relatively low. At a certain contact pressure, the fruits and vegetables come into contact with the contact.
[0074]
Therefore, the contact area is constant, the energy transfer efficiency is constant, and as a result, accurate frequency change information can be obtained, and the hardness of fruits and vegetables can be accurately measured.
Also, since the fruits and vegetables come into contact with the contact at a constant contact pressure according to the type of fruits and vegetables, that is, the types of soft to hard fruits and vegetables, the hardness of the fruits and vegetables is measured without damaging the fruits and vegetables. It is possible to do.
[0075]
Moreover, in this case, it is only necessary to adjust the compression length of the elastic member and control the elastic pressure by controlling the elastic pressure adjusting mechanism according to the type of fruits and vegetables, so that the hardness measurement work is simple. It is very convenient to measure the hardness of all kinds of fruits and vegetables.
Furthermore, according to the present invention, since the tip of the contact has a substantially spherical shape, the contact area with the fruits and vegetables does not change, so that it is possible to carry out a constant and accurate hardness measurement. This is an extremely excellent invention having a remarkable and unique effect.
[Brief description of the drawings]
FIG. 1 is a schematic front view of an embodiment of an apparatus for measuring hardness of fruits and vegetables according to the present invention.
FIG. 2 is a schematic sectional view of an embodiment of the apparatus for measuring hardness of fruits and vegetables in FIG. 1;
3 (A) is a partially enlarged cross-sectional view illustrating a use state of FIG. 2, and FIG. 3 (B) is an end view in an A direction of FIG. 3 (A).
FIG. 4 is a circuit configuration diagram of a filter circuit used in a gain change correction circuit.
FIG. 5 is a frequency-gain-phase characteristic curve diagram showing the principle of the fruit and vegetable hardness measuring apparatus of the present invention.
FIG. 6 is a schematic sectional view of another embodiment of the hardness measuring apparatus for fruits and vegetables of the present invention.
FIG. 7 is a schematic sectional view of another embodiment of the hardness measuring apparatus for fruits and vegetables of the present invention.
FIG. 8 is a schematic sectional view of another embodiment of the hardness measuring apparatus for fruits and vegetables of the present invention.
FIG. 9 is a schematic sectional view of another embodiment of the hardness measuring apparatus for fruits and vegetables of the present invention.
FIG. 10 is a graph showing the pressing pressure of a hardness meter with fruits and vegetables.
FIG. 11 is a schematic sectional view of a conventional fruit and vegetable hardness measuring apparatus.
[Explanation of symbols]
10 Hardness measuring device
12 Hardness measuring device body
14 gripper
16 Operation display
18 contacts
20 operation buttons
20a Power button
20b Setting button
21 Flange
22 Display window
24 Sensor unit
25, 27 connector
26 control unit
28 Sensor unit case
30 Sensor holder
34 Sensor body
36 vibrator
38 Detector
40 spring member
41 Guide member
42 Support
44 Sliding guide member
48 opening
50 Tip
52 Tip opening
54 Tip
56 Gain change correction circuit
56G gain characteristic curve
58 Amplifier circuit
60 Self-excited oscillation circuit
62 Frequency measurement unit
64 Hardness measuring unit
65 Display
66 storage unit
68 Input section
70 Spring pressure adjustment mechanism
72 Spring pressure adjusting member
56GP gain maximum value
A Fruits and vegetables
AMP amplifier circuit
C11 Capacitor
f1 center frequency
f2 center frequency
f11 resonance frequency
f12 resonance frequency
G1 gain
G11 gain
G12 gain
MG gain characteristic curve
MG1 gain characteristic curve
P11 Gain maximum value
P12 Gain maximum value
P1 gain maximum value
R11 resistance element
R12 resistance element
R13 resistance element
R14 resistance element
V12 Reference power supply terminal
Vin input terminal
Vout output terminal
Δf Frequency change
Δf1 Frequency change amount
ΔG Gain change
Δθ phase difference
θ1 input phase
θ11 I / O combined phase difference
θ2 output phase
θ56 characteristic curve

Claims (12)

A contact for contacting fruits and vegetables;
A vibrator for vibrating the contact,
A self-excited oscillation circuit that returns the vibration information of the vibrator to a resonance state in a state where the contact is in contact with fruits and vegetables,
A vegetable and vegetable hardness measuring device that measures the hardness of fruits and vegetables based on a change in vibration of a vibrator that has come into contact with the fruits and vegetables via a contactor, based on frequency change information from the self-excited oscillation circuit.
In a state where the contact and the vibrator are urged so that the contact protrudes from an opening at the tip end of the hardness device main body through an elastic member having a predetermined elastic constant according to the type of fruits and vegetables. , Detachably attached to the hardness measuring device body,
Thereby, the hardness of the fruits and vegetables is measured at a predetermined contact pressure according to the type of the fruits and vegetables by replacing the elastic member having the predetermined elastic constant according to the type of the fruits and vegetables with the hardness measuring device main body. An apparatus for measuring the hardness of fruits and vegetables, comprising a pressure adjusting mechanism, characterized in that the apparatus is configured so as to be capable of being used. A contact for contacting fruits and vegetables;
A vibrator for vibrating the contact,
A self-excited oscillation circuit that returns the vibration information of the vibrator to a resonance state in a state where the contact is in contact with fruits and vegetables,
A vegetable and vegetable hardness measuring device that measures the hardness of fruits and vegetables based on a change in vibration of a vibrator that has come into contact with the fruits and vegetables via a contactor, based on frequency change information from the self-excited oscillation circuit.
Forming a sensor body from the contact and the vibrator,
The sensor body is housed in the sensor unit case in a state where the contact body is urged through an elastic member having a predetermined elastic constant so as to protrude from the distal end opening of the sensor unit case,
The sensor unit case is detachably attached to the hardness measuring device main body so that the contact protrudes from a distal end opening of the hardness device main body,
Thereby, by replacing the sensor unit case provided with an elastic member having a predetermined elastic constant according to the type of fruits and vegetables with respect to the hardness measuring device main body, at a predetermined contact pressure according to the type of fruits and vegetables. An apparatus for measuring the hardness of fruits and vegetables, comprising a pressure adjusting mechanism, characterized in that the hardness of fruits and vegetables can be measured. A contact for contacting fruits and vegetables;
A vibrator for vibrating the contact,
A self-excited oscillation circuit that returns the vibration information of the vibrator to a resonance state in a state where the contact is in contact with fruits and vegetables,
A vegetable and vegetable hardness measuring device that measures the hardness of fruits and vegetables based on a change in vibration of a vibrator that has come into contact with the fruits and vegetables via a contactor, based on frequency change information from the self-excited oscillation circuit.
The contactor and the vibrator, through an elastic member, from the tip opening of the hardness device main body, in a state where the contactor is urged to protrude, and mounted on the hardness measurement device main body,
In accordance with the type of fruits and vegetables, comprises an elastic pressure adjusting mechanism that controls the elastic pressure by adjusting the compression length of the elastic member,
An apparatus for measuring the hardness of fruits and vegetables comprising a pressure adjusting mechanism, wherein the hardness of fruits and vegetables can be measured at a predetermined contact pressure by controlling the elastic pressure adjusting mechanism. The hardness measuring device for fruits and vegetables according to any one of claims 1 to 3, wherein the tip of the contact is substantially spherical. The hardness measuring device for fruits and vegetables according to any one of claims 1 to 4, wherein the elastic member is a spring member. 5. The hardness measuring device for fruits and vegetables according to claim 1, wherein the elastic member is at least one kind of elastic member selected from silicone resin, epoxy resin, and rubber. In a state where the contact is in contact with fruits and vegetables, via a self-excited oscillation circuit, the vibration information of the vibrator that vibrates the contact is fed back to a resonance state,
A method for measuring the hardness of fruits and vegetables, which measures the hardness of fruits and vegetables, based on a change in vibration of a vibrator in contact with the fruits and vegetables via a contactor, based on frequency change information from the self-excited oscillation circuit,
In a state where the contact and the vibrator are urged so that the contact protrudes from an opening at the tip end of the hardness device main body through an elastic member having a predetermined elastic constant according to the type of fruits and vegetables. , Detachably attached to the hardness measuring device body,
Thereby, the hardness of the fruits and vegetables is measured at a predetermined contact pressure according to the type of the fruits and vegetables by replacing the elastic member having the predetermined elastic constant according to the type of the fruits and vegetables with the hardness measuring device main body. A method for measuring the hardness of fruits and vegetables. In a state where the contact is in contact with fruits and vegetables, via a self-excited oscillation circuit, the vibration information of the vibrator that vibrates the contact is fed back to a resonance state,
A method for measuring the hardness of fruits and vegetables, which measures the hardness of fruits and vegetables, based on a change in vibration of a vibrator in contact with the fruits and vegetables via a contactor, based on frequency change information from the self-excited oscillation circuit,
Forming a sensor body from the contact and the vibrator,
The sensor body is housed in the sensor unit case in a state where the contact body is urged through an elastic member having a predetermined elastic constant so as to protrude from the distal end opening of the sensor unit case,
The sensor unit case is detachably attached to the hardness measuring device main body so that the contact protrudes from a distal end opening of the hardness device main body,
Thereby, by replacing the sensor unit case provided with an elastic member having a predetermined elastic constant according to the type of fruits and vegetables with respect to the hardness measuring device main body, at a predetermined contact pressure according to the type of fruits and vegetables. A method for measuring the hardness of fruits and vegetables, comprising measuring the hardness of fruits and vegetables. In a state where the contact is in contact with fruits and vegetables, via a self-excited oscillation circuit, the vibration information of the vibrator that vibrates the contact is fed back to a resonance state,
A method for measuring the hardness of fruits and vegetables, which measures the hardness of fruits and vegetables, based on a change in vibration of a vibrator in contact with the fruits and vegetables via a contactor, based on frequency change information from the self-excited oscillation circuit,
The contactor and the vibrator are attached to the hardness measuring device main body via an elastic member, in a state where the contactors are urged to protrude from the distal end opening of the hardness device main body,
According to the type of fruits and vegetables, the hardness of the fruits and vegetables is measured at a predetermined contact pressure by controlling an elastic pressure adjusting mechanism that controls an elastic pressure by adjusting a compression length of the elastic member. Kind of hardness measurement method. The method for measuring the hardness of fruits and vegetables according to any one of claims 7 to 9, wherein the tip of the contact is substantially spherical. The method for measuring the hardness of fruits and vegetables according to any one of claims 7 to 10, wherein the elastic member is a spring member. The method for measuring the hardness of fruits and vegetables according to any one of claims 7 to 10, wherein the elastic member is at least one kind of elastic member selected from a silicone resin, an epoxy resin, and a rubber.

Images