JPS6036014B2 - Adjustment method and device for electrode device of electric resistance grain moisture meter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrical resistance grain moisture meter, and more particularly to a method and apparatus for adjusting the spacing between measurement electrodes of an electrical resistance grain moisture meter and sample grain pressing force.

Measuring the moisture content of grains using an electrical resistance type grain moisture meter means measuring the electrical resistance of grains.

In detail, the grain to be measured is held between one electrode and its electrical resistance is measured.
It is necessary to keep the voltage between the electrodes, the distance between the electrodes, the amount of sample grain to be measured, and the force applied to the sample grain constant during measurement.If these parameters are not kept constant, measurement accuracy will deteriorate. Among the above measurement parameters, the "interelectrode voltage" can be easily set, and the "amount of sample grain to be measured" can be kept constant by using a sample dish. It is known from experience that even if there is some variation in the amount of sample grain, the accuracy of grain moisture measurement is not significantly affected. The biggest problem with measurement accuracy is
``electrode spacing'' and ``pressure force on sample grain.'' The structure of the electrode device of a moisture analyzer is generally such that the upper electrode and lower electrode are placed vertically opposite each other with a gap between the main body, and the upper electrode is screwed into the opening of the main body, and can be screwed in and unscrewed. 1, it is possible to raise and lower the main body.

Further, when the upper electrode is screwed into the main body, a stopper is provided to limit the distance from the lower electrode to a predetermined value or less. On the other hand, the lower electrode is supported on the main body by an elastic member, such as a leaf spring. In this way, with a predetermined amount of the sample grain placed in the sample dish sandwiched between the upper and lower electrodes, it is necessary to set the electrode spacing to a predetermined value and at the same time apply a predetermined pressing force to the sample grain. Furthermore, it is preferable that the sample grains held between the upper and lower electrodes be in a pulverized state.

For this purpose, a plurality of radial grooves are provided in the lower surface of the upper electrode and in the sample-receiving surface of the sample pan, through which the sample grain is ground by screwing the upper electrode. The electrode spacing between the upper and lower electrodes is determined in consideration of the predetermined pressing force and the degree of pulverization of the sample. The predetermined spacing between the upper and lower electrodes is determined statistically and empirically taking into account the following conditions: 1. Good reproducibility of the measured values 2. Amount of sample grain 3. Degree of crushing of the sample grain 4 Lifespan of elastic member 5: The degree of abrasion due to the use of the groove provided on the lower surface of the upper electrode.

Pressurizing sample grains is very difficult because it is necessary to maintain a predetermined distance between the electrodes to a predetermined value as described above.

As mentioned above, the pressing force is set to a predetermined value by adjusting the elastic force of the leaf spring supported on the main body.
Conventionally, this adjustment has been made using a special spring gauge. In this step, remove the upper electrode from the main body,
Instead, a special spring gauge is screwed in to apply a predetermined displacement to the lower electrode plate, and the pressure force applied by the leaf spring to the lower electrode at this time is measured using the special spring gauge. If the measurement result is smaller than a predetermined value, the leaf spring is adjusted to increase the pressing force, and conversely, if it is larger, the leaf spring is adjusted to decrease it.
The above method requires time and effort to remove and reattach the upper electrode from the main body.

Furthermore, it is difficult to adjust the pressure to be applied uniformly over the entire electrode surface. Particularly when the lower electrode is held by a plurality of leaf springs, it is very difficult to accurately adjust each leaf spring so as to apply pressure uniformly over the entire electrode surface. The present invention provides a method for adjusting the pressurizing force for sample grains and an apparatus for adjusting the force, which eliminates the above-mentioned drawbacks.

According to the present invention, a pressure measuring device having a pressure detection sensor is inserted between an upper electrode and a lower electrode of an electrode device of a moisture meter. The portion having a thickness equal to the predetermined electrode spacing.

In this state, when the upper electrode is screwed into the main body by a predetermined amount, the lower electrode is displaced downward against the leaf spring via the inserted pressure measuring device. In this state, the pressing force of the leaf spring may be adjusted to a predetermined value while reading the value detected by the pressure sensor. It is particularly preferable to use a strain gauge as the pressure sensor used in the pressure adjustment device.

It is well known that the electrical signals detected by a strain gauge are sent to a strain gauge having a bridge resistor device for observation. With the above method, you can adjust the pressure to a predetermined value by simply inserting the pressure measuring device between the electrodes and adjusting the pressure to a predetermined value without having to remove the upper electrode from the moisture analyzer body. becomes very easy.

Furthermore, by installing multiple pressure detection sensors in the pressure measurement device and measuring the local pressure of the lower electrode at multiple locations, the pressing force of the leaf spring can be adjusted so that the pressing force of the lower electrode is uniform over the entire surface. It is also easily possible to do so. Hereinafter, the present invention will be explained in detail in the form of examples along with the accompanying drawings. In order to clearly understand the features and effects of the present invention, an outline of an electrode device for a grain moisture meter and a conventional method for adjusting the pressing force of electrodes will first be explained with reference to FIGS. 1 to 5.

First, an electrode device of an electric resistance grain moisture meter will be explained with reference to FIGS. 1 to 4.

An insert 5 having a male thread is screwed into an opening □ provided in the upper part of the electrode device main body 4, and a screw member 1 constituting the upper electrode is screwed into this. A screw handle 9 is provided at the top of the screw member 1. A lower electrode 2 is arranged below the upper electrode screwed into the main body 4, and the lower surface of the lower electrode is fixed to the main body 4 with a screw 6 and is fixed upwardly by the tip of an adjusting screw 8 carried by a leaf spring 7. is under pressure. This adjustment screw 8 is screwed into a screw hole provided at the tip of the leaf spring 7, and is secured with a lock nut 8a at a predetermined adjustment position. As clearly shown in FIG. 2, in this embodiment, the leaf spring 7 presses the lower electrode 2 from the left and right sides. The leaf spring provided on the left side is designated by the reference numeral 7'. The adjustment screw 8' and lock nut 8a' on the left side are also similar to those on the right side. The upper end portion of the insert 5 protrudes upward from the main body 4, and a stopper ring 10 is iron plated on a threaded portion provided on the outer periphery of the protrusion. When the handle 9 is rotated to screw in the upper electrode, that is, the threaded portion 1, a ring 9' provided on the lower surface of the handle 9 comes into contact with this stopper ring 10. By appropriately adjusting the amount of iron inset in the stopper ring 10, the distance between the upper electrode 1 and the lower electrode 2 can be adjusted to a predetermined value. Referring to FIG. 4, the lower electrode 2 has an upwardly extending peripheral wall 2'.

The peripheral wall 2' surrounds the upper electrode 2 in a U-shape and serves as a guide for receiving the sample plate 2a. The upper end of the peripheral wall 2' abuts against the lower surface of the step in the closed portion of the main body 4.
When the handle 9 is rotated and the upper electrode 1 is screwed in until it collides with the stopper in the absence of the sample plate 2a, the distance between the upper electrode 1 and the lower electrode 2 becomes (L).

(See Figure 1). However, this spacing (L) does not provide a predetermined electrode spacing for sample grain moisture measurements. This interval (L) is determined based on the design considering various factors such as the insertion of the sample plate 2a, the rigidity of the leaf springs 7 and 7', the grinding condition of the life sample grain, and the reproducibility of the measured values. be.
As shown in FIG. 3, the lower surface of the upper electrode 1 has radial grooves 35 for ensuring grip of the grain to be measured and for crushing the sample.
There are several. Figure 4 shows the sample tray 2a containing a fixed amount of grains inserted into the moisture meter and the upper and lower electrodes 1 and 2.
The figure shows a state in which it is sandwiched between the two.

Since the sample grain and the sample plate 2A are present, when the upper electrode 1 is screwed in until the ring 9' of the handle 9 abuts against the stopper ring 10, the lower electrode 2 is displaced downward against the leaf springs 7, 7'. Due to the displacement of the leaf springs 7, 7', the lower electrode 2 receives an elastic reaction force. This reaction force applies a pressing force to the sample grain on the sample plate 2a. In the above state, the lower electrode 2 is moved further downward by a distance (
So) it will be displaced.

As a result, the distance between the lower electrode and the upper electrode becomes (L+h). It is necessary to set the pressing force of the leaf springs 7, 7' to a predetermined pressing force, and to set the distance between the upper electrode and the lower electrode (L+T) to the predetermined electrode distance. An adjustment method for this purpose will be explained below. If the leaf springs 7, 7' are improperly adjusted, the predetermined electrode spacing will not be maintained even if the sample blood 2a containing a predetermined amount of sample grain is held between the electrodes.

This is because the pressing force is not a predetermined value, so the crushed state of the sample grains is different. The adjustment method is to set the electrode spacing to a predetermined electrode spacing during moisture measurement, and adjust the adjusting screws 8, 8' so that the elastic force of the leaf springs 7, 7' applied to the lower electrode 2 becomes a predetermined pressing force.

In the conventional adjustment method, as shown in FIG. 5, the upper electrode 1 is removed from the main body 4, and a special spring gauge 11 is screwed into the main body 4 in its place.

The structure of this special spring gauge 11 is that a plunger 14 is slidably inserted into a cylinder 11', a spring retainer 15 is fixed to the upper end of the plunger 4, and the spring retainer 15 is screwed into the cylinder 11' from the upper end. A compression spring 12 is arranged between the handle plug 21. A fitting 20 having a central entrance is screwed into the lower end of the cylinder 11'. An opening □ is provided in a part of the lower peripheral wall of the cylinder 11', and the spring retainer 1
The outer peripheral side of No. 5 can be observed. A scale line 16 is provided on the outer circumferential surface of the spring retainer 15, and a scale line 18 is provided on the entrance side 17 of the cylindrical wall to correspond to this scale line.
(See Figures 5A, 5B, and 5C). A plunger 4 projects outwardly from the cylinder 11' through the central opening of the fitting 20.

Remove the upper electrode 1 and attach the special spring gauge 11 to the main body 4.
When the plunger 14 is screwed in so that the lower surface of the fitting 20 contacts the stopper 10, the plunger 14 touches the lower electrode 2.
is displaced downward against the leaf springs 7, 7', and at the same time the spring 12 in the gauge 11 is also compressed. The compression spring 12 of this special spring gauge 11 provides a predetermined electrode spacing (L+〆) for moisture measurement between the upper electrode and the lower electrode when the scale line 16 of the spring retainer 15 matches the scale line 18. The lower electrode is pressed downward with a force corresponding to a predetermined pressing force.
If the adjusting screws 8, 8' of the leaf springs 7, 7' are properly adjusted and a predetermined pressing force is applied to the lower electrode 2, the scale line 16 and Scale line 1
8 matches.

This is because the leaf springs 7, 7' are balanced with the downward elastic force of the compression spring 12 of the gauge 11 at a predetermined electrode spacing (L+h). If the adjustment of the leaf springs 7, 7' is incorrect, for example, if the scale line 16 is placed above the scale line 18 as shown in FIG. 5A, the elastic force of the leaf springs 7, 7' will be greater than a predetermined value. On the other hand, if the scale line 16 is below the scale line 18 as shown in Fig. 5C, the leaf springs 7, 7
′ indicates that the elastic force is smaller than a predetermined value.

Therefore, the adjusting screws 8, 8' may be appropriately adjusted so that the scale lines 16 and 18 coincide as shown in FIG. 5B. By the above method, it is possible to adjust the spacing between the upper and lower electrodes of the electrode device of the moisture meter and the pressing force of the sample grain to predetermined values. However, in order to screw the special spring gauge 11 into the electrode device body, the upper electrode 1 is required to be removed and installed.

Furthermore, since only the combined force of the left and right leaf springs 7, 7' can be measured, it is impossible to accurately determine whether the left and right leaf springs 7, 7' are adjusted equally. For example, even if the pressing force of the lower electrode 2 is adjusted to a predetermined value (X kg) by the combined force of the left and right leaf springs 7, 7', the pressing force of each of the left and right leaf springs 7, 7' is It is not necessarily adjusted to be 2. That is, as an extreme example, the pressing force of the right leaf spring 7 may be adjusted to ×/3, and the force of the left leaf spring 7' may be adjusted to ×/3. If there is a difference in the adjustment force between the left and right leaf springs 7 and 7', the pressure applied to the sample grain via the lower electrode 2 will be uneven, and a uniformly distributed pressure will not be applied, so high precision measurement cannot be expected. . The adjustment method and adjustment device of the present invention for solving the above-mentioned conventional measurement methods will be described below in the form of examples.

Referring to FIG. 6, the tip of the pressure measuring device 26 of the present invention is inserted through the insertion opening of the sample dish 2a of the electrode device main body 4.

The handle 9 is rotated and screwed in until the upper electrode 1 collides with the stopper ring 10. The tip of the pressure measuring device 26 is held between the upper electrode 1 and the lower electrode 2. Two strain gauges are embedded in the tip of the pressure measuring device 26 so that the elastic forces of the left and right leaf springs 7, 7' applied to the lower electrode 2 can be electrically detected. This detected value is directly read on a tremmeter in the manner shown in FIG.
Since this strain meter is well known, a brief description will be given here. Strain gauge 43, 4 serving as the detection end
The signal from the bridge resistor section 60 including 3' is sent to the amplifier 6.
1 and displayed on the indicator 62. This indicator 6
The elastic force of the leaf springs 7, 7' can be easily determined by the display 2. Here, details of the pressure measuring device 26 of the present invention will be explained.

Referring to FIGS. 7A and 7B, the pressure measuring device 26 includes a plate-shaped portion 40 that is inserted into the sample plate insertion opening of the main body 4,
This plate-like portion 40 includes a flat frame portion 42, a steel plate 47, and a protrusion 4.
5, 45', 48.

The steel plate 4 has an upper surface of the flat frame portion 42 and a wear-resistant surface.
7 is removably attached. Since this steel plate 47 rubs against the upper electrode 1, it needs to have a wear-resistant surface, and since it is susceptible to wear and tear, it is designed to be replaceable. Protrusions 45, 4 are provided on the lower surface of the plate-like portion 42.
5' is provided. When the pressure measuring device 26 is inserted into the main body 4, the protrusions 45, 45' come into contact with positions on the lower electrode corresponding to the tips of the adjusting screws 8, 8' of the leaf springs 7, 7', respectively. There is. Projections 45, 45'
The height (H) from the lower end of the steel plate 47 to the upper surface of the steel plate 47, that is, the plate-shaped portion 40 is designed to match the predetermined electrode spacing (L+〆). For this reason, when the measuring device 26 is inserted into the main body 4 and the upper electrode is screwed into the main body, the measuring device 26 is held between the upper electrode 1 and the lower electrode 2, but in this case, the interval between the upper electrode 1 and the lower electrode 2 is inevitably It is set at a predetermined interval (L+So). The plate-like portion 42 is provided with a slot 46 so as to divide the protrusions 45, 45' into left and right parts. This slotted groove 46 allows the projections 45, 45' to be slightly displaced independently of each other. That is, it is possible to individually measure the pressing force of the leaf springs 7, 7' of the electrode device using two strain gauges. The protrusion 48 in the middle part of the plate-like part 42 works in cooperation with the protrusions 45 and 45' to stabilize the plate-like part 42 on the lower electrode 2 when the pressure measuring device 26 is inserted into the main body 4. It is something. Electric cords 50, 50' are connected to the rear end side of the pressure measuring device 26.
are connected by connecting fittings 49, 49'. The other ends of the electrical cords 50, 50' are connected to a strain meter (see FIG. 10). Referring to FIGS. 8 and 9, projections 45, 45' of plate-like portion 42 of pressure measuring device 26 are shown.
Circular recesses 44, 44' are provided on the back side at positions corresponding to , and strain gauges 43, 43' are inserted into these recesses 44, 44', respectively.

Recesses 44, 44' provide grooves 52, 52' rearward (toward the right in FIGS. 8 and 9);
Strain gauges 43, 43' lead wires 51, 51 in 52'
' is embedded in each. Strain gauge 43, 43'
The lead wires 51, 51' are connected to the recesses 44, 44' and the grooves 52,
52' using a filler and fixed therein. The strain gauges 43, 43' and lead wires 51, 51' are sufficiently protected by a steel plate 47. Lead wires 51, 5
1' are connected to electric cords 50 and 50', respectively, and transmit detection signals to a strain meter (see FIG. 10). By using the pressure measuring device 26 with the above configuration, the adjustment screws 8, 8' are used to make the pressing forces of the left and right leaf springs 7, 7' equal, and the resultant force becomes a predetermined pressing force. be done.

In the embodiment of the present invention, the pressure detection sensors of the pressure measuring device have been described as strain gauges 43, 43', but various known pressure detection sensors can be used.

For example, the protrusions 45, 45' can be used as piston ends of a small hydraulic cylinder that protrudes from the closed end of the plate-shaped portion 42, so that the piston receives pressurizing force, and the hydraulic pressure in the cylinder can be directly read with a hydraulic pressure gauge. It is also possible to adjust the pressing force. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows a partial sectional view of a known moisture meter electrode device, Fig. 2 shows a part of the bottom of a known moisture meter electrode device, and Fig. 3 shows a known moisture meter electrode device. FIG. 4 is the same as FIG. 1, but shows the measurement state of the moisture meter electrode device,
FIG. 5 is a diagram showing a state in which a known adjustment device for a moisture meter electrode device is attached to the electrode device, FIGS. 5A to 5C are partially enlarged views of FIG. 5, and FIG. 7A is a side view of the pressure measuring device which is a part of the adjustment device of the present invention, FIG. 7B is a bottom view of FIG. 7A, and FIG. Figure 9 is an enlarged view of the blood-dish line part of the figure, with a part cut away.
FIG. 10 is a diagram schematically showing an electric circuit diagram of the adjusting device of the present invention.

DESCRIPTION OF SYMBOLS 1... Upper electrode, 2... Lower electrode, 3... Elastic member, 26... Pressure measuring device, 40... Plate-shaped part, 4
2...Flat frame portion, 43...Pressure detection sensor, 45.
... Protrusion, 46... Slit book, 47... Steel plate.

Figure 6 Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 5A Figure 5B Figure 5C Figure 7A Figure 7B Figure 8 Figure 9 Figure 10

Claims (1)

[Claims] 1. A main body, upper and lower electrodes disposed on the main body so as to be movable up and down, and elasticity provided between the main body and the lower electrode to press the lower electrode upward. and a pressing force adjustment device provided on the elastic member to adjust the pressing force of the elastic member, the sample grain is held between the upper electrode and the lower electrode, and the electricity of the sample grain is adjusted. The adjustment device is used for an electrode device of an electric resistance type grain moisture meter which measures the moisture content of grain by measuring the resistance of the grain. The adjusting device includes a plate-shaped portion inserted between the upper and lower electrodes, and a lower surface of the plate-shaped portion. a protrusion that protrudes and comes into contact with the lower electrode at a position corresponding to the pressing force adjustment device when the plate-shaped portion is inserted between the upper and lower electrodes, and a pressure embedded in the protrusion; an adjustment device, characterized in that the distance from the upper surface of the plate-shaped portion to the tip of the protrusion provides a predetermined distance between the upper electrode and the lower electrode. 2. In the adjustment device for an electrode device according to claim 1, the number of the pressing force adjustment devices of the electrode device is plural, and the number of the protrusions and the pressure sensors is the same as the number of the pressing force adjustment devices. An adjustment device characterized by: 3. The adjustment device for an electrode device according to claims 1 and 2, wherein a portion of the plate-shaped portion that contacts the upper electrode is made of a removable steel plate. Device. 4. The adjusting device according to claims 2 and 3, characterized in that a groove is provided between the protrusions. 5. The adjusting device according to any one of claims 1 to 4, wherein the pressure sensor is a strain gauge.