JP2000046758A - Method and apparatus for measuring water content by microwave and tea making process control method used therein - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a microwave permeation type moisture meter for measuring low moisture capable of measuring the moisture of tea leaves or the like of low water content with high accuracy. SOLUTION: The transmission path between a microwave transmitter and a microwave receiver is formed from a microstrip line 10 and picked leaves before, after or during processing by a tea making machinery are positioned so as to be allowed to face to the microstrip line 10, and the water content of tea leaves is calculated from the difference in receiving level generated by the absorption of a microwave by the moisture contained in tea leaves. Since tea leaves close to the microstrip line 10 become a measuring object, if tea leaves A of a constant bulk or more are positioned on the microstrip line 10, a measuring error is not generated even when a sampling amt. is different. Since the measurement of the wt. of tea leaves becomes unnecessary and the measuring error of a wt. is not included, water content can be measured highly accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for measuring the moisture content of tea leaves and the like using microwaves, and in particular, to reduce variation in each measurement and to reduce the number of peripheral devices as compared with conventional ones. The present invention relates to a method and apparatus for measuring moisture content by microwaves, and a method for controlling a tea making process using the same.

[0002]

BACKGROUND OF THE INVENTION Processing of tea leaves in a tea factory substantially occupies a large number of steps that substantially promote the drying of the tea leaves, and specifically has a water content of about 3 (based on the weight of the tea leaves having no moisture).
Kneading and drying is performed from steamed leaves of about 60% to finally obtain crude tea having a water content of about 5%.

[0003] The steps for this include a leafing step, a rough kneading step, a kneading step, a middle kneading step, a middle kneading step, a fine kneading step, a drying step and the like. Understanding the rate is an important factor in the operation of tea making equipment to obtain high quality products.

Therefore, recently, as devices for grasping the water content, electric resistance type moisture meters, microwave type moisture meters,
A near-infrared moisture meter is used, but there is room for improvement in the following points. First, an electric resistance type moisture meter measures the electrical resistance of tea leaves by placing tea leaves between the electrodes. In principle, only moisture on the surface of tea leaves can be measured, so the measurement result tends to depend on the surface resistance. Therefore, it is difficult to grasp the water content of the whole tea leaves, and it is not enough to use as data for controlling the tea production line. Also, if a voltage higher than a certain level is applied depending on the moisture content of the tea leaves, insulation breakdown will be caused and the measurement cannot be performed.
In the middle massage machine, measurement is performed at a voltage of 12 V, which complicates measurement and data processing.

[0005] In addition, a microwave-type moisture meter requires a load cell or the like, which is a measuring device for measuring the weight of tea leaves, so that the configuration of the measuring system must be complicated.

A near-infrared moisture meter can measure moisture to the inside of tea leaves slightly more than the electric resistance type moisture meter, but in principle can only measure moisture on the surface of tea leaves. In addition, since the irradiation range of near-infrared rays is very narrow, there is a drawback that only a small part of the sample can be measured.
Furthermore, the near-infrared moisture meter is expensive and thus lacks versatility.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of such a background, and does not require a weight measuring means unlike the conventional apparatus, and can reduce the cost of the entire apparatus.
Another object of the present invention is to develop a novel microwave moisture content measurement method and apparatus capable of improving measurement accuracy, and a tea manufacturing process control method using the same.

[0008]

According to a first aspect of the present invention, there is provided a method for measuring water content by using a microwave, wherein a transmission path between a microwave transmitter and a receiver is formed by a microstrip line and processed by a tea-making apparatus. Before, after processing or during processing, the tea leaves are positioned facing the microstrip line, and the water content of the tea leaves is calculated from the difference in reception level caused by the absorption of microwaves by the moisture contained in the tea leaves. It is characterized by the following. According to the invention,
Because tea leaves near the strip conductor are to be measured, if tea leaves of a certain bulk or more are located on the strip conductor,
Even if the sampling amounts are different, no measurement error occurs. In addition, since the measurement of the weight of the tea leaves is not required and the measurement error of the weight is not included, the water content can be measured with high accuracy.

According to a second aspect of the present invention, in addition to the above requirement, the microwave is measured once or plural times using a single frequency or a plurality of frequencies. It is characterized by the following. According to the present invention, the reliability of data is increased by performing measurement using microwaves of different frequencies or by performing measurement a plurality of times, and more accurate measurement can be performed.

The method for measuring moisture content by microwave according to claim 3 is characterized in that, in addition to the above requirements, the tea leaves are pressed and the measurement is carried out in this pressed state or after the pressed state is released. Become. ADVANTAGE OF THE INVENTION According to this invention, since the density of the tea leaf for every measurement is made uniform, more highly accurate measurement can be performed.

According to a fourth aspect of the present invention, in addition to the requirement of the third aspect, the pressure at which the tea leaves are pressed is selected according to the processing state of the tea leaves. It is characterized by that. According to the present invention, the leafing step, the rough kneading step, the kneading step, the middle kneading step,
By selecting an optimal pressure different for each processing step, such as a middle kneading step, a fine kneading step, and a drying step, highly accurate measurement can be performed.

According to a fifth aspect of the present invention, in addition to the above requirements, the microstrip line is located on the back surface of the receiving member, and the sample is located on the surface of the receiving member. It becomes as. According to the present invention, since the tea leaves do not directly touch the strip conductor, wear and damage of the strip conductor can be prevented.

According to a sixth aspect of the present invention, in addition to the above requirements, the method for measuring the moisture content by applying a vibration to a tea leaf positioned facing the microstrip line to make the density uniform is performed. Become a feature. ADVANTAGE OF THE INVENTION According to this invention, in order to make the density of a tea leaf uniform, more highly accurate measurement can be performed.

According to a seventh aspect of the present invention, there is provided an apparatus for measuring moisture content by using a microwave, wherein a transmission line comprising a microstrip line is formed between a microwave transmitter and a receiver, and the transmission line is accommodated in a sampling device for tea leaves. It is characterized in that it is located inside the department. ADVANTAGE OF THE INVENTION According to this invention, highly accurate water content measurement can be performed for the tea leaves accommodated in the tea leaf accommodating part, without measuring the weight of the tea leaves.

Further, in the apparatus for measuring moisture content by microwave according to claim 8, in addition to the requirement according to claim 7, the tea leaf accommodating portion includes a bottom plate, a pair of side plates rising on both sides of the bottom plate, and A top plate provided opposite to the bottom plate,
The shutter plate and the back plate that stand up front and rear of the bottom plate are configured by a plate frame member as an element, and one or both of the pair of side plates, or one or both of the top plate and the bottom plate, includes the micro plate. A strip line is provided. According to the present invention, the disposition position of the microstrip line can be selected according to the attachment position of the moisture content measuring device limited by the tea-making equipment, so that the versatility can be improved.
Further, a plurality of measurement data can be obtained by measuring the tea leaves of the same sample with the microstrip lines attached at two places, and the measurement accuracy is improved.

According to a ninth aspect of the present invention, in addition to the requirement of the eighth aspect, the apparatus for measuring moisture content by microwaves has a discharge function by arranging the back plate to be movable along the side plate and the bottom plate. The plate is formed as a plate, and one or both of a plate frame member provided with the microstrip line and another plate frame member opposed to the plate frame member provided with the microstrip line are configured to be movable. It is characterized in that it is an action plate. According to the present invention, the tea leaves taken into the tea leaf accommodating section can be measured with higher accuracy in order to uniform the density of the tea leaves for each measurement by pressing with the pressing action plate, and further after the measurement. Since the tea leaves can be discharged by the discharge action plate, the water content of the tea leaves during processing can be measured by attaching the tea leaves to a device (rough rubbing machine or the like) constituting the tea production line.

According to a tenth aspect of the present invention, in addition to the requirement of the seventh, eighth or ninth aspect, the strip conductor in the microstrip line is provided with a protective plate having an appropriate thickness. It is characterized by being coated. According to the present invention, since the tea leaves do not directly touch the strip conductor, the electric field generated between the strip conductor and the conductor plate is not disturbed, and a highly accurate moisture content can be measured. Further, corrosion, wear and damage of the strip conductor can be prevented.

Further, the moisture content measuring apparatus using microwaves according to the eleventh aspect is characterized in that, in addition to the requirement according to the eighth, ninth or tenth aspect, an airbag is provided on the pressing action plate. According to the present invention, by pressing the tea leaves against the microstrip line by the airbag, the density of the tea leaves for each measurement is made more uniform, so that more accurate measurement can be performed.

Further, the apparatus for measuring water content by microwave according to claim 12 is the same as that of claim 8, 9, 10 or 1.
In addition to the features described in 1, the tea leaf housing section is provided with a vibration mechanism. ADVANTAGE OF THE INVENTION According to this invention, since the density of the tea leaf located facing a microstrip line is made uniform, more highly accurate measurement can be performed.

Further, the apparatus for measuring water content by microwave according to claim 13 is the same as that of claim 7, 8, 9, 10, 10.
In addition to the requirements described in 1 or 12, a cleaning mechanism for removing tea leaves, moisture and the like attached to the microstrip line is provided. According to the present invention, since the tea leaves of the previous measurement do not remain on the microstrip line, highly accurate measurement can be performed.

Further, the apparatus for measuring water content by microwave according to claim 14 is characterized in that:
In addition to the features described in 12 or 13, a mechanism is provided that enables a position at which the microstrip line faces the tea leaves to be changed. According to the present invention, the reliability of data is increased by continuously performing measurements at different measurement locations on the same sample, and more accurate measurements can be performed.

According to a fifteenth aspect of the present invention, there is provided a method for controlling a water content by using a microwave and a method for controlling a tea making process using the apparatus, wherein a transmission line between a transmitter and a receiver of the microwave is formed by a microstrip line. Before processing by tea making equipment,
After processing or during processing, the tea leaves are positioned facing the microstrip line, and from the difference in reception level caused by the absorption of microwaves by the moisture contained in the tea leaves, the water content of the tea leaves is calculated, and It is characterized in that the timing of taking out the tea leaves from the tea-making equipment is determined according to the water content. According to the present invention, the moisture content of the tea leaves is measured with high accuracy, and the timing of removing the tea leaves from the tea-making equipment is determined based on this value. High quality processed tea leaves can be obtained. The problem is solved by using the configuration of the invention described in each of the claims.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the structure of a microwave moisture content measuring apparatus of the present invention will be described, and then a microwave moisture content measuring method using the same and a tea making process controlling method using the same will be described. . As shown in FIG. 1, the moisture content measuring device 1 of the present invention is integrally formed with a sampling device 2 provided on a side plate portion 21 of a rough rubbing machine 20 in a tea factory, for example. Of course, as for the location of the moisture content measuring device 1, an appropriate position such as the front surface of the rough massage machine 20 can be selected.

First, the sampling device 2 will be described. In this device, a tea leaf accommodating section 3 is formed as shown in FIG.
And a pair of side plates 5R, 5 rising on both sides of the bottom plate 4.
L, a top plate 8 provided to face the bottom plate 4, and a rectangular space defined by a plate frame member including a shutter plate 6 and a back plate 7 standing up and down from the bottom plate 4. A slight clearance is provided between the bottom plate 4 and the back plate 7 and the side plate 5. In the following description, the front means the side of the rough massage machine 20 to which the sampling device 2 is attached, and the rear means the opposite direction.

The back plate 7 is configured so as to be movable back and forth along the side plate 5 and the bottom plate 4 to serve as a discharge plate, and one of the side plates 5 (in the present embodiment, as an example, the side plate 5R). A pressing plate is formed by being movable along the bottom plate 4 so as to approach and separate from the other side plate 5 (in the present embodiment, for example, the side plate 5L). For this reason, the cylinder 7a,
5a is fixed, and these rods are respectively fixed to the back surface of the back plate 7 and the back surface of the side plate 5R.

A nylon brush 17 as an example of a cleaning mechanism is provided on one side of the back plate 7 (the side plate 5L side).
Is provided over the entire area in the longitudinal direction. As the cleaning mechanism, an air purge mechanism having a nozzle or the like that appropriately blows compressed air, in addition to the one that wipes the upper surface of the side plate 5L by moving the back plate 7, such as the nylon brush 17, a rubber spatula, a cloth, or the like, is adopted. Can also.

The shutter plate 6 opens and closes the tea leaf accommodating portion 3 by moving up and down along the front end surfaces of the pair of side plates 5 opposed to each other. Is fixed to the upper end surface.

Further, a microstrip line 10 is provided on the surface of the other side plate 5L, which faces the movable side plate 5R, on the side of the tea leaves accommodating section 3, and a strip conductor in the microstrip line 10 is provided. 12
The side surface is covered with an appropriate protective plate 16 made of an insulating material. In the present embodiment, the protective plate 16 has a thickness of 0.4 m.
m acrylic plate was used.

Hereinafter, the above-mentioned microstrip line 10 will be described in detail. Microstrip line 10
Is a microwave transmission line which is structurally obtained by removing one of the conductor plates of a symmetrical strip line, but can be considered as an electrically deformed two parallel line. The structure is such that a strip-shaped strip conductor 12 is positioned above the conductor plate 11 as shown in FIG. 3A. In order to hold the strip conductor 12, the conductor plate 11 and the strip conductor 12, a dielectric 13 is inserted as a spacer.

As a material of the conductor plate 11 and the strip conductor 12, it is preferable to use a metal having high conductivity such as copper and iron, but it is also possible to use a metal having excellent corrosion resistance such as stainless steel. The dielectric 13 is made of glass fiber, ceramic, or the like containing silicone, fluorine resin, epoxy resin, or the like.

In the present embodiment, among the electromagnetic waves, in particular, a microwave of 4 GHz (λ 扱 う 7.5 cm) is treated as an example of the 3 to 5 GHz band (λ ≒ 10 to 6 cm), and therefore, at this frequency. The characteristic impedance of the microstrip line 10 is different between the transmitter 19a and the receiver 19b.
The dimensions and the like are appropriately designed so as to match with. In the present embodiment, as an example, the relative permittivity ε _r is used as the dielectric 13.
The width of the strip conductor 12 was 2 to 5 mm, and the interval between the strip conductor 12 and the conductor plate 11 was 1 to 1.5 mm, using epoxy containing glass fiber of 4.7. Of course, these numerical values change depending on the value of the relative permittivity ε _r of the dielectric 13, the frequency of the microwave used, and the like. Further, the frequency of the electromagnetic wave to be used is not limited to the microwave of the above 3 to 5 GHz band, and an appropriate high frequency can be selected as long as the frequency is absorbed by moisture.

[0032] Strip conductor 12 in the present embodiment
As shown in FIG. 4 (a), the shape of the side plate 5R is such that a straight portion is provided on the diagonal line of the side plate 5R.
By arranging the input end 12a and the output end 12b on one side, the portion below the diagonal line of the side plate 5R is routed over almost the entire area. As shown in FIG. 4 (b), such a pattern of the strip conductor 12 is routed over substantially the entire area along each side of the side plate 5R, or at several places as shown in FIG. 4 (c). Various embodiments can be adopted, such as turning over the entire surface of the side plate 5R.

In the microstrip line 10, the impedance of the non-linear portion of the strip conductor 12 is different from that of the linear portion, so that microwaves are reflected or radiated. It is preferable to form an H-vent having an obtuse angle by cutting off an acute angle portion or an H-corner having a curve.

The input end 1 of the strip conductor 12
As shown in FIG. 4, high frequency connectors 14a and 14b such as SMA and BNC are attached to the 2a and the output end 12b, respectively, and connected to the transmitter 19a and the receiver 19b by a coaxial cable C or the like.

Here, the moisture content measuring apparatus 1 of the present invention described above.
The measurement principle will be described. The stripline includes a symmetrical stripline and an asymmetrical stripline. A symmetrical stripline can be thought of as a modification of a coaxial line, in which the coaxial line is transformed into a square waveguide or a square waveguide, and the sidewall is finally removed. The state of the electromagnetic field in a plane perpendicular to the transmission direction is as shown in FIG. 3B, where an electric field (solid line in the figure) is generated from the lower surface of the upper surface of the strip conductor 12 'toward the conductor plate 11'. A magnetic field (dashed line in the figure) occurs around the conductor 12 '.

On the other hand, the asymmetrical strip line is structurally obtained by removing one of the conductor plates of the symmetrical strip line, but it is considered that the two parallel lines are electrically deformed. That is, as shown in FIG. 3A, an electric field (solid line in the figure) is generated from the lower surface of the strip conductor 12 toward the conductor plate 11, and a magnetic field (dashed line in the figure) around the strip conductor 12 is generated. I have. Further, an electric field is generated from the upper end of the strip conductor 12 toward the conductor plate 11 by the edge effect, and the width of the strip conductor 12 is equivalently increased by the electric field by the edge effect. Microstrip line 10 used in the present invention
Is an asymmetric type and is designed to have a transmission frequency of 3 to 5 GHz as an example.

The microstrip line 10 as described above
The attenuation of the microwave propagating through the antenna becomes conductor loss, dielectric loss, and radiation loss. That is, in the measurement system shown in FIG. 4, the difference between the output value from the transmitter 19a and the input value to the receiver 19b is the sum of the conductor loss, the dielectric loss, and the radiation loss. When a microwave of a predetermined level is transmitted from the transmitter 19a in a state where the sample (tea leaf A) is not positioned above, the microwave of a level attenuated by the loss arrives at the receiver 19b. The level is used as the reference value.

Then, as shown in FIG.
When the tea leaf A is positioned facing the strip conductor 12 in the microstrip line 10 with the interposition of the conductor plate 1 from the upper end of the strip conductor 12
When the natural frequency of the electric dipole of H ₂ O coincides with the frequency of the microwave,
In this portion, a resonance phenomenon of molecules occurs and microwaves are absorbed, and the microwaves are attenuated according to the water content of the tea leaves A. In this regard, the principle of the moisture content measurement by microwave of the present invention is as follows.
This is different from the measurement principle of the electric resistance type moisture meter described in the background of the invention.

The difference between the level of the microwave transmitted from the transmitter 19a and the level of the microwave arriving at the receiver 19b is due to the absorption of the microwave by the tea leaves A as a sample and the attenuation by the loss. The value obtained by subtracting the attenuation (reference value) due to the loss from the value at this time is the microwave absorption M (dB) of the tea leaves A. From this value M (dB), the water content G (%) of the sample (tea leaf A) can be obtained by the following equation. G = aM + b (a and b are correction values) Note that the correction values a and b are values obtained by experiments in advance, and are obtained by using an M value obtained by measurement using the above measurement system and a weighing scale. This is determined because a correlation can be found between the weight value of the tea leaf A before and after drying and the moisture value (actually measured value) obtained from the weight value.

As in the measurement principle described above, the moisture contained in the tea leaves A located in a state of being deposited near the upper portion of the strip conductor 12 (tea leaves A located in the space where the electric field is generated) absorbs microwaves. And the strip conductor 1
The tea leaves A located away from 2 do not block the electric field and do not absorb microwaves, and thus are not measured. Therefore, as long as the thickness of the tea leaves A located on the microstrip line 10 is secured to some extent, no change occurs in the measured value due to the difference in the amount of tea leaves A deposited (sampling amount). This part is different from the measurement principle of the moisture content by the microwave of the present invention and the measurement principle of the electric resistance type moisture meter described in the background of the invention. That is, in the electric resistance type, a sample (tea leaf A) located between the electrodes is used as a part of the circuit, and the resistance value of the sample (tea leaf A) is measured to obtain a water content correlated with the resistance value. Is measured. However, actually, the water droplets adhering to the surface of tea leaf A are
Since the resistance value is lower than that, a large amount of current flows in this water droplet, the measurement result tends to depend on the moisture attached to the surface and becomes inaccurate, and it is difficult to grasp the entire moisture contained in the tea leaf A. It has become.

The basic embodiment of the moisture content measuring apparatus 1 of the present invention is as described above. Hereinafter, a method of measuring moisture content by microwave using the device and a method of controlling a tea making process using the same will be described. explain.

(1) Measurement of Reference Value First, microwave transmission is performed in a state where the cylinder 6a is extended and the shutter plate 6 closes the opening 21a, that is, in a state where the tea leaves A are not located in the tea leaf housing portion 3. When a microwave is supplied from the transmitter 19a to the microstrip line 10, which is a path, the microwave having the level attenuated by the loss inherent in the microstrip line 10 arrives at the receiver 19b. Value.

(2) Sampling Then, as shown in FIG. 5 (a), when the cylinder 6a is contracted and the shutter plate 6 is retracted, the tea leaf container 3 is opened at the front face, so that it is scraped up by a massager or leaves. The obtained tea leaf A is taken into the tea leaf accommodating section 3.

(3) Pressing of Tea Leaves Next, as shown in FIG. 5 (b), the cylinder 6a is extended and the shutter plate 6 is advanced to close the front surface of the tea leaf housing portion 3 and Regulates the entrance of tea leaves A. Then, as shown in the auxiliary projection view of FIG.
Is stretched so that the side plate 5R faces the side plate 5L, and the pressure according to the processing state of the tea leaves A set in advance (2 kg as an example)
/ Cm ² ), the tea leaves A sandwiched between the side plates 5R and 5L have a uniform density by eliminating the air between the tea leaves A, and the microstrips disposed on the side plates 5L. The line 10 comes into close contact with the protection plate 16 with the protection plate 16 interposed therebetween.

(4) Measurement and Calculation of Moisture Content Next, after an appropriate time has elapsed, a microwave is supplied from the transmitter 19a to the microstrip line 10 in this state. Absorption takes place. As a result, the level of the microwave transmitted from the transmitter 19a toward the microstrip line 10 does not match the level of the microwave received by the receiver 19b. The water content of the tea leaf A is calculated from the difference.

(5) Discharge of tea leaves Next, as shown in FIG.
a is contracted to move the side plate 5R away from the side plate 5L, and further the cylinder 6a is contracted to retract the shutter plate 6 to open the front surface of the tea leaf accommodating portion 3, and then extend the cylinder 7a to advance the back plate 7. Tea leaves A located in the tea leaf container 3
Is returned from the opening 21a into the rough massage machine 20. At this time, since the nylon brush 17 as a cleaning mechanism wipes the surface of the protective plate 16, all the tea leaves A located in the tea leaf accommodating section 3 can be returned to the rough rubbing machine 20, and the next and subsequent measurements are accurately performed. be able to.

(6) Control of Tea Making Process Next, the value of the water content obtained as described above is processed by a control panel provided in the rough rubbing machine 20 or a control panel for controlling the entire tea making line. When the rate becomes a suitable value in the rough rubbing machine 20, the processing by the rough rubbing machine 20 is stopped, and the tea leaves A are discharged and transported to the next step.

[0048]

[Other Embodiments] In the above-described basic embodiment, various modifications of the apparatus configuration and the measuring method as described below are possible.

[0049]

[Other Embodiments such as Arrangement of Microstrip Line] First, the arrangement of the microstrip line 10 is not limited to one place, but as described in claim 8, the side plate 5L is attached to the side plate 5L. In addition, you may make it arrange | position also with respect to the side plate 5R which opposes this side plate 5L. In this case, the tea leaves A accommodated in the tea leaf accommodating section 3 are transferred to the side plate 5.
The measurement can be performed at two places: the microstrip line 10 provided on the L and the microstrip line 10 provided on the side plate 5R, and the measurement accuracy can be improved. In addition to the bottom plate 4 as shown in FIG. 6, the microstrip line 10 may be provided with the shutter plate 6, the back plate 7, or the top plate 8 (not shown).

The arrangement of the microstrip line 10 on the plate frame member is essentially the same as that of the strip conductor 12 to the conductor plate 1.
Since the electric field toward 3 only needs to pass through the tea leaf storage unit 3,
As described in claim 5, the microstrip line 10 can be provided on the back surface of the side plate 5 as a receiving member. In this case, the side plate 5 is made of a material having a relative dielectric constant close to 1. By doing so, the protection plate 16 becomes unnecessary. In addition, since the microstrip line 10 is located outside the tea leaf housing 3, the manufacture and maintenance of the device are simplified.

In protecting the strip conductor 12, instead of providing the protective plate 16, the strip conductor 12 is coated with an insulating resin such as a fluororesin so that the tea leaves A and the like on the strip conductor 12 are coated. Can also be prevented from adhering. In the above description, the case where the moisture content measuring device 1 is configured integrally with the sampling device 2 provided in the tea making equipment is described. However, the present invention is not limited to this, and the components having a common configuration are described below. 1 is also applicable to a case where the device is configured as an independent device.

[0052]

[Other Embodiments with Different Pressing Actions] In the above embodiment, the pressing action on the tea leaves A was performed by the side plate 5R, but the point is that it is only necessary to keep the density of the tea leaves A constant. Then, it can also be performed as shown below. First, a pressing action can be performed by the top plate 8, and specifically, as shown in FIGS. 8 and 9 and as shown in FIG. A cylinder 8a is connected to a top plate 8 facing the bottom plate 4 to form a pressing plate.

As described in the eleventh aspect, by providing an airbag 15 on the top plate 8 as the pressing action plate, the pressing action can be performed by the airbag 15. As shown in the enlarged view of FIG. 6A, the airbag 15 has a concave portion formed on one side of the top plate 8, and an expansion member 15a such as a rubber plate is fixed in the concave portion, and its peripheral portion is tightly fixed. By doing so, a chamber is formed, and the expansion member 15a does not protrude from the recess in a contracted state.

Here, the measurement using the water content measuring device 1 thus constituted will be briefly described. First, (1) measurement of the reference value and (2) sampling were performed in the same manner as in the previous embodiment. Then, (3) the tea leaves are pressed. That is, as shown in FIG. 6 (b), the cylinder 8a is extended, the top plate 8 is advanced toward the bottom plate 4 to a preset position, and air is supplied to the airbag 15 to expand the expansion member 1
When the 5a is inflated, the tea leaves A sandwiched between the airbag 15 and the bottom plate 4 eliminate the air between the tea leaves A to have a uniform density and protect the microstrip line 10 disposed on the bottom plate 4 from the air. The plate 16 comes into close contact with the plate 16 interposed therebetween. Then, (4) measurement and calculation of moisture content,
(5) Discharge tea leaves. In the above description, the case where the moisture content measuring device 1 is configured integrally with the sampling device 2 provided in the tea making apparatus is described. However, the present invention is not limited to this, and the portions having the same configuration are described below. The present invention is also applicable to a case where the device 1 is configured as an independent device.

[0055]

[Another Embodiment for Improving Precision Instead of Pressing Action]
In the above embodiment, the measurement is performed in a state where the tea leaf A is pressed in order to improve the measurement accuracy. However, depending on the properties of the tea leaf A, the measurement may be performed without the pressing. Specifically, in the case of tea leaves A having a low water content, such as tea leaves A processed by a fine rubbing machine, the air between the tea leaves A is removed at the stage of sampling without pressing, so that the density becomes uniform. No need to press. In this case, the vibration is applied to the tea leaves A by providing the vibration mechanism 18,
The density between the tea leaves A may be positively made uniform. More specifically, a vibration mechanism 18 is provided on the bottom plate 4 as an example of a plate frame member as described in claim 12 and indicated by phantom lines in FIGS. 5 and 6. As an example of the vibration mechanism 18, A known configuration such as a vibration motor having a weight with an eccentric center of gravity on the rotating shaft of the motor, or a combination of a crank mechanism and a motor may be employed. By using such a vibration mechanism 18, the tea leaves A
Is not crushed. In the above description, the case where the moisture content measuring device 1 is configured integrally with the sampling device 2 provided in the tea making apparatus is described. However, the present invention is not limited to this, and the portions having the same configuration are described below. The present invention is also applicable to a case where the device 1 is configured as an independent device.

[0056]

[Another Embodiment of Arrangement Mode of Microwave Transceiver] In the above embodiment, a transmitter 19a and a receiver 19b are provided at a place remote from the sampling device 2, and these are connected to the microstrip line 12 by a connector. 14 and the coaxial cable C, but a small transmitting device and a receiving device or a voltmeter or the like as a substitute for the transmitting device and the receiving device are directly mounted on the back surface or the like of the plate frame member constituting the tea leaf housing unit 3. You can also. In this case, a change in the measurement environment due to the bending of the coaxial cable C or the like can be eliminated, and more accurate measurement can be performed. In the above description, the case where the moisture content measuring device 1 is configured integrally with the sampling device 2 provided in the tea making apparatus is described. However, the present invention is not limited to this, and the portions having the same configuration are described below. The present invention is also applicable to a case where the device 1 is configured as an independent device.

[0057]

[Other Embodiments with Different Measurement Locations] In the above embodiment, the microstrip line 10 has one line for the plate frame member, and measures a fixed measurement site for one sample. However, a mechanism may be provided to enable the position at which the microstrip line 10 faces the tea leaf A to be changed, as described in claim 14.
Specifically, as an example, by providing a plate frame member provided with the microstrip line 10 so as to be rotatable or slidable by an appropriate mechanism, the relative position between the microstrip line 10 and the tea leaves A can be changed, This makes it possible to continuously perform measurements at different measurement locations on the same sample. Further, even when a plurality of microstrip lines 10 are provided on the plate frame member and the measurements on the individual microstrip lines 10 are performed continuously and sequentially, the measurement at different measurement locations can be performed on the same sample. Can be performed continuously. In the above description, the case where the moisture content measuring device 1 is configured integrally with the sampling device 2 provided in the tea-making equipment has been described.
The present invention is also applicable to a case where the moisture content measuring device 1 is configured as an independent device.

[0058]

Next, another embodiment of the measuring method will be described.

[0059]

[Other Embodiments of Measurement Timing] As for the measurement timing, it is essential only that the density of the tea leaves A be kept constant. May be pressed by the side plate 5R or the like, and after the air between the tea leaves A is eliminated to make the density uniform, the pressing by the side plate 5R or the like is released, and the measurement may be performed at that time.

[0060]

[Other Embodiments of Microwave Used for Measurement] The microwave used in the above embodiment has one frequency (4 GHz).
However, as described in claim 2, for example, 3 to
A plurality of measurements can be performed using microwaves of a plurality of different frequencies in the 5 GHz band, and an average of these measured values can be taken, so that the measurement accuracy can be improved.

[0061]

[Embodiment used as an individual measuring device] The water content measuring device 1 of the present invention is constructed integrally with the sampling device 2 provided in the tea-making equipment as described above, and is separately measured from the sampling device 2. It can be configured as a device and installed in a tea factory. First, as an example, as shown in FIG. 7 (a), the inside of a cylinder 30 is used as a tea leaf accommodating section 3, a bottom plate 4 is provided at the bottom of the cylinder 30, and a top sliding as a piston that slides inside the cylinder 30. A plate 8 is used. The microstrip line 10 is provided on the upper surface of the bottom plate 4, and the microstrip line 10 is covered with a protective plate 16.

As shown in FIG. 7B, a vibration mechanism 18 is provided on the bottom plate 4, a microstrip line 10 is disposed on the bottom plate 4, and a tray D is mounted on the microstrip line 10. Can also be placed. The material of the tray D is preferably a material having a relative dielectric constant close to 1, such as PP or PE. Such a moisture content measuring device 1
The tea leaves A sampled by a belt conveyor or the like are supplied automatically or manually, and the water content of the tea leaves A is set in the electric field from the strip conductor 12 to the conductor plate 13. Measurement becomes possible.

[0063]

According to the present invention, there is no need for a weight measuring means as in the conventional apparatus, a cost reduction of the entire apparatus can be realized, and a new hydrous method using microwaves can improve the measuring accuracy. It is possible to provide a rate measuring method and apparatus, and a method for controlling a tea making process using the same.

[Brief description of the drawings]

FIG. 1 is a side view showing a state in which a moisture content measuring device of the present invention is attached to a rough massage machine.

FIG. 2 is a vertical sectional side view and an auxiliary projection view showing the moisture content measuring device of the present invention.

FIG. 3 is a cross-sectional view illustrating a state of an electric field in a microstrip line and a target strip line.

FIG. 4 is a plan view showing various forms of a microstrip line.

FIG. 5 is an explanatory diagram showing step by step a method of measuring a water content by a microwave.

FIG. 6 is an explanatory view showing step by step another embodiment of the method for measuring the water content by microwaves.

FIG. 7 is a side view showing a moisture content measuring device configured as an individual measuring device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Moisture content measuring device 2 Sampling device 3 Tea leaf accommodation part 4 Bottom plate 5 Side plate 5a Cylinder 5R Side plate 5L Side plate 6 Shutter plate 6a Cylinder 7 Back plate 7a Cylinder 8 Top plate 8a Cylinder 9 Housing 10 Microstrip line 11 Conductor plate 12 Strip conductor 12a Input end 12b Output end 13 Dielectric 14 Connector 14a Connector 14b Connector 15 Airbag 15a Expansion member 16 Protective plate 17 Nylon brush 18 Vibration mechanism 19a Transmitter 19b Receiver 20 Coarse massager 21 Side plate 21a Opening 30 Cylinder A Tea leaf C Coaxial cable D saucer

Continued on the front page (72) Inventor Nobuto Tsukamoto 1-2-3 Nakajima, Kikukawa-cho, Ogasa-gun, Shizuoka Prefecture (72) Inventor Hitoshi Miura 1451-2 Nishikata, Kikukawa-cho, Ogasa-gun, Shizuoka F-term (reference) 4B027 FB02 FP01 FP11 FP24 FP27 FP34 FP47 FP55 FR08 FR17

Claims (15)

[Claims] 1. A transmission path between a microwave transmitter and a receiver is formed by a microstrip line, and tea leaves before, after or during processing by a tea-making apparatus are exposed to the microstrip line. A method for measuring the water content of a tea leaf, wherein the moisture content of the tea leaf is calculated from a difference in reception level caused by absorption of the microwave by moisture contained in the tea leaf. 2. The method according to claim 1, wherein the microwave is measured once or a plurality of times using a single frequency or a plurality of frequencies. 3. The method for measuring moisture content by microwave according to claim 1, wherein the tea leaves are pressed, and the measurement is performed in the pressed state or after the pressed state is released. 4. The pressure at the time of pressing the tea leaves is selected according to the processing state of the tea leaves.
The method for measuring water content by microwave according to claim 3. 5. The water content by microwave according to claim 1, wherein the microstrip line is located on a back surface of a receiving member, and a sample is located on a surface of the receiving member. Measuring method. 6. The method according to claim 1, wherein vibrations are applied to tea leaves positioned facing the microstrip line to make the density uniform, and then the measurement is performed.
The method for measuring water content by microwaves as described. 7. A microwave transmission system comprising: a transmission line comprising a microstrip line formed between a microwave transmitter and a microwave receiver; and wherein the transmission line is located in a tea leaf accommodating portion of the sampling device. Moisture content measuring device. 8. The tea leaf storage unit includes a bottom plate, a pair of side plates rising on both sides of the bottom plate, a top plate provided facing the bottom plate, and a shutter plate and a back plate rising before and after the bottom plate. It is composed of a plate frame member as an element,
The water content measuring apparatus according to claim 7, wherein the microstrip line is provided on one or both of the pair of side plates, or on one or both of the top plate and the bottom plate. . 9. The back plate is configured to be movable along the side plate and the bottom plate to serve as a discharge action plate, and a plate frame member provided with the microstrip line or the microstrip line is provided. 9. The moisture content measuring device using microwave according to claim 8, wherein one or both of the other plate frame members facing the plate frame member are configured to be movable to form a pressing action plate. 10. The microwave moisture content measuring device according to claim 7, wherein the strip conductor in the microstrip line is covered with a protective plate having an appropriate thickness. 11. The apparatus according to claim 8, wherein an air bag is provided on the pressing plate. 12. The microwave moisture content measuring device according to claim 8, wherein a vibration mechanism is provided in the tea leaf accommodating portion. 13. The water content by microwaves according to claim 7, wherein a cleaning mechanism is provided for removing tea leaves, moisture and the like attached to the microstrip line. Rate measuring device. 14. The moisture content measurement by microwave according to claim 8, 9, 10 or 11, further comprising a mechanism capable of changing a position where the microstrip line faces the tea leaves. apparatus. 15. A transmission path between a microwave transmitter and a receiver is formed by a microstrip line, and tea leaves before, after or during processing by a tea-making apparatus are exposed to the microstrip line. From the difference in the reception level caused by the absorption of microwaves by the moisture contained in the tea leaves, calculate the water content of the tea leaves, and determine the timing of removing the tea leaves from the tea-making equipment according to the water content. Claims 1, 2, 3,
A method for controlling a water content using a microwave according to claim 4, 5, or 6, and a method for controlling a tea making process using a device for measuring a water content using a microwave according to claim 7, 8, 9, 10, 11, 12, 13, or 14.