JPS58178223A - Weight measuring device - Google Patents

Abstract

PURPOSE:To obtain the weight measuring device having highly accurate measuring accuracy, by providing two detecting means, which detect the deflection of a strain yielding body at both right and left sides of the free end part of the strain yielding body provided in a simplified Roberval's parallel motion mechanism, averaging the signals obtained by a detecting means, and using the result for detecting the weight, thereby eliminating shift errors perfectly. CONSTITUTION:When a material to be measured is mounted on an upper pan 3, the load is transmitted to the strain yielding body 1 through an auxiliary member 4 of the strain yielding body, and the strain yielding body 3 is deformed. When the shift errors are yielded in the directions of an X axis and a Y axis, moments owing to the shift errors act on the strain yielding body 3 through the auxiliary member 4 of the strain yielding body. The direction of the X axis is not affected because of the Roberval's parallel motion mechanism. The deformations of the deflection and torsion owing to the load simultaneously appear at the free end part of the strain yielding body 3 by the shift errors in the direction of the Y axis. Reflecting plates 5a and 5b, which are provided on both right and left sides, are displaced up and down, and light beams are projected to solar batteries at the different positions in light receiving elements 7a and 7b. The solar batteries, which generate output voltages, are judged, and the averaging operation is performed by a microcomputer operating circuit. The result is converted into a weight value and it is displayed by a display element.

Description

[Detailed description of the invention] The present invention relates to a weighing device that eliminates eccentricity errors.

Various configurations of single-layer equipment have been proposed, but
There is a device that detects the strain or deflection (displacement) due to the bending moment of the beam A (tin), converts it into weight KW, and displays it. FIG. 1 shows the main part of the conventional single-layer device, that is, the configuration of the strain-generating body pigtail. The strain-generating body 1 constitutes a roughly mouth-paddle-pal mechanism, and in addition to the horizontal member on which the load of the object to be measured acts, four horizontal members are provided below, and both ends of the upper and lower horizontal members are connected to each other. They are connected by other members and one end is fixed to the inner wall of the device. In Figure i9, 2 is a strain r-zo, which is pasted on each part of the strain body ■.
This is to detect the strain of the flexure element 1 due to the load.

Now, the load on the object to be measured acts on the position indicated by the thick arrow in the figure, but it does not necessarily apply only to the downward component.
19 for eccentrically placing a good object to be measured placed on an upper plate (not shown);
A moment is often generated in the X@ or Y-axis direction in the figure.

Therefore, for eccentricity in the X-axis direction, it does not affect the selection value using the c1/4-pal mechanism, but for zero eccentricity in the Y-axis direction, the strain-generating body There is a drawback that l causes twisting, which affects the detected strain value and causes a so-called eccentricity error.

As a method for reducing the above device error, it is necessary to increase the @W of the strain-generating body 1 to increase the rigidity against the screw, and to improve the relationship between the strain C caused by the bending moment and the strain S′ caused by the torsion force. Although it is possible to eliminate the eccentricity error to some extent by setting the accuracy to In order to find it, there is also a device that has a function to change the inertia H from pass/fail 8" to # x = 13 - M, but since the configuration is non-zero and double track, it is sufficient in terms of accuracy. .

The present invention has been proposed in view of the above points, and includes two sets on both left and right sides of the free end of the strain-generating body constituting the approximately donkey-pal mechanism, for detecting the deflection (displacement) on both the left and right sides. By providing a detection means and using these detections to average the signals obtained from the stages for weight detection, it is possible to completely eliminate eccentricity errors and provide a weighing device with high measurement precision and one button. purpose.

Hereinafter, the present invention will be described in detail with reference to the drawings showing embodiments.

Figures 2 and 3 show the first embodiment of the present invention, with Figure 2 showing the configuration of the flexure body and its surroundings, and Figure 3 showing the configuration of the signal processing section from detection to weight display. FIG.

To explain the structure of the 21st part, the free end of the flexure element l fixed to the inner wall of the device is
I VCrj convex portions 1m and 1b are provided, and the lower end of the flexure element auxiliary member 4 that holds the h plate 3 is this convex portion 111m.

1b, and applies a load to the strain body 3.

On the other hand, reflective plates 5m and 5b are attached to the end faces of the protrusions 111m and 1b at an angle θ with the - line, and the light emitting element 6a* (51s and the light receiving element 7m, An optical path of ?b is formed.Here, the light emitting elements 6m and 6b emit a light beam with a certain area, and the emitted light beam passes through the reflection plates 5m and 5b.
The light is guided to the light receiving element 7as7b via the light receiving element 7as7b. Light receiving element 7a
, 7b are constructed by linearly arranging n solar cells, for example, and the output can be obtained only from the nine solar cells that are hit by the light beam, so that their positions can be known. That is, the deflection of the flexure element 1 is converted into a change in the angle of the reflectors 5m and 5b, which changes the reaching potential of the reflected light, and the change in position is detected by the light receiving elements rh and rb. be.

Next, the configuration of the signal processing section will be explained based on FIG. Note that since the detection circuits attached to both the right and left sides of the free end of the strain body 1 are the same, only one side is illustrated, and the other components are omitted. Now, one end of the n(- solar cells in the light receiving element 7a is commonly grounded, and the other end is connected to the input end of the Fi multi-channel 7 receiver 8m. One of them is connected to the output wheel, and the output signals of the n solar cells are sequentially selected by a multiplexer control circuit in the microcomputer calculation circuit 11.

Next, the output terminal of the multiplexer 8a is connected to the head antenna 9.
&! ! JL is connected to one input terminal of the converter lOa through r, reference voltages r and f are applied to the other input terminals of the converter lOa, and the output terminal is connected to the microcomputer calculation circuit &g.
It is connected to the input port of i1.

Operation e ([In this case, when the object to be measured is placed on the upper plate 3 7'
+, 6, a load is applied to the strain body l via the strain body auxiliary material 4, causing the strain body lLf shape to rise. At this time, if the object to be measured is placed at the center of the plate attachment part of the upper plate 3, only a downward charge will act, but if it is eccentrically placed in the direction of MrP IA to strain body 3 via 4
The fit Y moment will be at work. Here, there is no effect on the eccentricity in the X-axis direction due to the adoption of a roughly donkey-pal mechanism, and one position in the Y-direction causes the distortion body l
(screw) t- will occur. Therefore, the deflection due to the load and the screw O deformation appear at the same time at the free end of the strain-generating body 3, and nine reflections are provided on both left and right sides of the free end. a and Sb are displaced up and down around a certain value, and project light beams to different positions of the light receiving elements 7m and 7b. Let us assume that the solar cells hit by the original beam are the m-th and m'-th solar cells, respectively! Luchi! Lexa 8a (8b
) by 11! :Select the output of the solar cells from the th to the nth in order and head un! After amplification by 9m (9b), m and C11' can be detected by comparing it with the reference voltage vr*f by the fecal meter lOa (lob) and distinguishing the solar cell tq producing the output voltage. can. When the microcomputer calculation circuit 11 detects m and m', it calculates the average of tn+m' and converts it into a weight value (since there is a linear relationship between the detected value and the weight value, it is multiplied by a constant and further a constant is added). As mentioned above, the deformation of the free end of the flexure element is a combination of the deflection due to the load and the screw), so m and m' are The center value is Vζ, and it is increased or decreased by the moment due to eccentricity, and the mourning value obtained by averaging the three values is ′,
No influence from the 4th position appears.

Next, FIGS. 4 and 5 show a second embodiment of the present invention, in which changes in the tension of the string are used as a means for detecting the displacement of the free end of the flexure element. . Fig. 4 shows the structure around the flexure element, where the protrusions 1m are provided on both left and right sides of the free end of the flexure element l, and lb is a vibrating string of 13m.
, 13b to a transducer (for example, an ultrasonic transducer) 14
It is connected to the vibrating piece 141e, and the string tension is changed by the displacement of the free end of the flexure element, and the vibration amplitude is changed.

Figure 5 shows the configuration of the signal processing section, with left and right O detectors RC)
To explain the configuration with reference to FIG. 5, which shows only one side of the transducer, the signal input terminal P of the vibrator 14m is connected to #IIIR so that the oscillation output of the reference oscillation circuit 15 is applied as a signal conductor.
Terminal Q, which outputs a voltage proportional to vibration, is connected to one input end of the controller 17m through the input beam, and a stepped waveform is connected to the other input end of the controller 17m. The output terminal of the converter/4 converter 17m is connected to the input port of the microcomputer arithmetic circuit 110. Here, the converter medium converter 17a1, the staircase oscillator 18#i, which constitutes a so-called successive approximation type φ converter, counts the number of 0 steps in the trench that matches the input signal in the microcomputer arithmetic circuit 11. In particular, it digitizes p-analog signals.

In operation, when the υ vibrating string 13m (13b) t) string tension changes due to the displacement of the end of the strain body 1011,
Wi exciter 14 (141t) 1 vibration m bait becomes concentrated, and this amplitude change is digitized by amplifier 16a (C16k), controller 17m (17b), etc., and sent as a detection signal to microcomputer calculation circuit 11K. . In the microcomputer operation circuit 11, as in the tenth embodiment described above,
The good signals obtained from both the left and right detection means are averaged, converted into a weight value, and displayed. In addition, it is not necessarily OK to use a ST7 case oscillator as a single converter; other methods of φ converter can also be used. It goes without saying that the same structure can be achieved even if seven types are used.

Figure 6 shows the external appearance of the Kukei Jutsuru body shown in the reference trench. The explanation will be omitted.

As described below, in the present invention, the deflection of the beam is determined by a strain-generating body that constitutes approximately a donkey-pal mechanism in a single layer that measures and displays the weight of the object to be measured, Two sets of detection means for detecting the displacement on both the left and right sides of the strain body OII, and the strain body are connected to an upper plate that straddles the free end of the strain body and on which the object to be measured is placed. The device is equipped with a flexure element auxiliary material and a signal processing section, and the signals obtained from the two sets of detection means are averaged, converted into a weight value, and displayed.
It is number 11 in that it does not cause errors even when the eccentricity of the wrinkled fixed object is measured, and it provides a high weighing accuracy.

4.11 N O Brief explanation No. 111 is a drawing showing the conventional O weighing ll0 II capital, No. 2 m
, Figure 11 and 3 are configuration diagrams showing an example of a real 110110-wheel.
1 to 411.1lISIIdjl! o A configuration diagram showing an embodiment, gsai is a reference diagram showing the outside of the weighing device O.

1... Straight distorted body, la, lk... Convex portion, 3... Upper plate, 4... Warm distorted body auxiliary material, 1ia, S... Reflective plant i 5atsb... Light emitting element, 7m, 7...light receiving element, @h, fib...multiglex, 1m, 9 toe head unde, 10a, lek, 17m, 17
k...computer/4-rater, 11...microcomputer operation am
, it...display element, 13m, 1:Th...vibrating string,
14m, 14k... Vibrator, 15... Reference generator m circuit, 14a, lIk... Ann 1118... Staircase generator aS.

Figure 1 Figure 2

Claims (3)

[Claims] (1) Determine and display the weight of the object to be measured by 7 meters (according to the angle of ♂-mu).
- Constituting strain-generating body and the free end of this strain-generating body on both left and right sides O
A two-layer detection means for detecting displacement, a flexure element auxiliary member that is placed on the 0*m end of the axial strain body and connects the upper plate on which the object to be measured is placed and the M strain body, and a signal 1. A weighing device which averages the good signals obtained by the two sets of detection means, converts it into a weight value, and displays it. (2) A patent claim in which the detection hand RFi is constituted by a traveling reflection plate disposed on both left and right sides of the free end of the flexure element, and a light emitting element and a light receiving element in which light l! is set via the reflection plate. Category ■ Weighing device described in item 1. (3) The detection means is configured by connecting a portion of the left and right sides of the free end of the straining body to a vibrator via a vibrating string, and vibrates the change in string tension due to the deflection of the strain body. The weighing device described in item 11 of the TiWfM calculation taken as the change in the vibration amplitude of the child @