JPS58182515A - Addition and division type electronic balance - Google Patents

Abstract

PURPOSE:To improve the accuracy of measurement, by detecting the electrostatic capacity or inductance generated in a sensor as a parameter of an oscillator, converting the oscillation frequency thereof to the weight value of a weighing object and displaying the same digitially. CONSTITUTION:If the weight value of a weighing object X is assumed to exist between addition and division weights W1 and W2, the operator turns a knob 16 by one division, then only the weight W1 among the W1-W5 is lifted. At the same time, a changeover switch 23 changes over and the weight value of only the weight W1 is displayed directly. For the remaining weight, the change component by the unbalance state of a balance beam 2 is changed to the change in electrostatic capacity or inductance and is added to the weight W1 through an oscillator 20 and a converter 21.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic digital display in a scale.

Conventional addition/subtraction scales have a mechanical pointer structure with many display parts, and these parts require dimensional accuracy, making adjustments such as adjusting the center of gravity of the pointer and adjusting the display error of the pointer due to assembly errors. Many of them have disadvantages, such as complicated mechanisms and scale-type displays that are extremely difficult to read.

The present invention uses an electric sensor in a part of a weighing machine scale that moves in proportion to the weight to be weighed, and the electrostatic capacitance generated between two parallel plates or in proportion to the moving distance of the wire ring and core. A moving part for changing the inductance generated in the wire ring is fixed, the capacitance or inductance generated in this sensor is detected as an oscillator parameter, and this oscillation frequency is converted into the weight value of the weighed object. The object of this invention is to electrically measure the weight value together with the added or subtracted weight and display it digitally to eliminate the above-mentioned drawback.

Embodiments will be described in detail below with reference to the drawings.

(A) is an example of a conventional balance-type addition/subtraction scale part, in which a ram (2) is provided on a fulcrum (1), and a balance weight (2a) is attached to one end (2a) of the ram (2). The plate holder that suspends the Wol and has a number (3) on the other end (2b) is a rod (
4)? : The lower end (4a) of the rod (4) is engaged with one end (6a) of the stay (6) suspended horizontally from the fulcrum (5) (additional way (W, ...W5.) is placed on a mounting table (7) fixed to a rod (4), and the punch (2) is balanced around the fulcrum (1).

The addition/subtraction weights (WL,...W++-) can be separated from each other, and the respective addition/subtraction weights (Wl/W5...
) are connected with a binding thread (8) (Fig. 2),
The uppermost adjustment way (W+) is connected to one end (10a) of an arm (10) rotatable about a shaft (9) by a hanging cord (11).

A tension spring (12) is stretched between the other end (10b) of the arm (10) and the base (13).
0c) is a convex □ part (10d), and this convex part (
10d) is in pressure contact with a recess (14a) of a cam (14), which will be described later.

The cam (14) rotates clockwise together with the knob (16) around the shaft (15), and the number of recesses (14a) of the cam (14) is determined by the weights (wI...w6...) in this embodiment. )
The knob (16) 'f is divided equally into one more number than the number of
: When rotated by one division, the convex part (10d) of the arm (10)
) is fitted into the four parts (14#) of the cam (14), and the arm (1o) is tilted around the axis (9) and the adjustment weight (wl
Addition/subtraction way of ws...) (Lift only wI1.

(Fig. 2) In this way, each time the knob (16) is rotated, the convex part (10dl) of the arm (10) is the concave part (10dl) of the cam (14).
4a, 14a") in sequence, and the arm (1
o) is the inclination angle (θ) in sequence around the axis (9) (Fig. 2))
It is possible to expand the weights and finally lift all the weights (W Bi w8...).

Therefore, if a weighed object (X) is placed on the pan (3) and the weight value of this weighed object (X) is the addition/subtraction weight (W+) and (W2
), turn the knob (16) by one division to change the (wl
) Lifting only (Figure 2) Inclination of the mallet (2) (amount of movement)
The structure is such that the weight is read and added to the weight of the addition/subtraction weight (wl) to display the weight.

CB) is an electrical sensor. This electrical sensor (
Although there are various types of B), this example uses two parallel flat plates (17
) using a capacitance type and wire ring (181J - this wire ring (1
8) A guidance method in which the core (19) is movable will be explained.

First, for a capacitive sensor using two parallel flat plates (17), the electrode plate (17a) is fixed and the electrode plate (17a) is placed on the base (13').
), and the movable electrode plate (17b), which moves oppositely to the fixed electrode plate (17a), is placed on the extension of the rod (4) or on the extension of the punch (2). Fix it.

Next, for the induction type sensor formed by a wire ring (18) and a core (19), either the wire ring (18) or the core (19) is fixed to the base (13") and moved. The other core (19) or wire ring (18) is fixed on the extension of the rod (4) or on the extension of the punch (2).

(20) is an oscillator. If the electric sensor (B) is a capacitive type, this oscillator (2o) is connected to two parallel plates (
17) The electrostatic capacitance (CI) of the amount of electricity generated between (G) (in the case of the induction method, the inductance (L) of the amount of electricity generated in the wire ring (18) is used as a parameter to oscillate, and these oscillation frequencies ( F) is converted into a weight value by a converter (21), and the weight value is digitally displayed on a display unit (22).

The most significant digit (22a) of the display section (22) is connected via a changeover switch (23);
23) is linked to the knob (16), and the knob (1
6) to remove the weights (WI...Wl・) (lifted weights (WI'・Ws'・
...)) Switch to change the weight value of the weight (23)
3, and this display is displayed separately from the display unit (22) as shown in FIG. Or, in the display section (22), the weight value of the lower digit (zzb) which is obtained by converting the amount of electricity generated in the electric sensor (B) into weight and the weight value corresponding to the addition/subtraction way) (WI...Ws...) are added and displayed together (Figure 3-2).

With the above configuration, the weight value of the weighed object (X) is calculated as the weight value of the weighed object [X] is
If the knob (16) is rotated by one division, the (W
At the same time as lifting only l), changeover switch (23)
changes and directly adds or subtracts the weight (WI) to the display section (22).
Only the weight value is displayed, and the remaining weight is displayed as a stack (2)
The change in the unbalanced state is converted into a change in the capacitance (0) or inductance (I, ) as described above, and is converted to the addition/division weight (Wl) via the oscillator (20) and converter (21). The weight of the weighed object (Xl) is displayed, or the addition/subtraction weight (WI) is displayed separately as described above.

In this way, the final weighing range is from 09- to the total weight of the addition/subtraction weights (W□...Ws...) and the unbalanced weight allowed by the stacking rod. can.

As mentioned above, the conventional display unit has a pointer-type mechanical structure, and as mentioned at the beginning, it has various drawbacks, but the present invention uses electrical processing to improve the balance of the pointer. No adjustment required (adjustment of center of gravity) ■ There are few parts, so there is no need to increase the dimensional accuracy of the parts so much ■ There is no adjustment due to display errors in the pointer due to assembly errors ■ Since the display is digital, reading accuracy is improved.

■ Even though the weighing range is wide, the moving distance of the sensor is small, so it is possible to provide a scale with excellent linearity and high accuracy.

■ Since only the unbalanced portion is electrically measured, relatively low electrical accuracy (especially temperature characteristics, etc.) is sufficient, making it possible to provide an electronic scale with high overall accuracy at low cost.

■ The circuit configuration is simple because the most significant digit on the display can be displayed directly by interlocking the knobs.

■ It has various effects such as simple mechanism.

[Brief explanation of the drawing]

Figure 1 is a simplified diagram of the load rod (2) in a balanced state. Figure 2 is a simplified diagram of the weighing state. Figure 3 is a block diagram showing the display section. FIG. 1.5...Fully point 2...Pile rod 2a...
One end 2b...Other end 3...Plate 4...Plate holder is a rod 6...Stay 7...Placement stand 13'
, 13'... Base 17... Two parallel flat plates 17a... Fixed electrode plate 17b... Movable electrode plate 18... Wire ring WO... Balance weight
Wl...Wl...Addition/subtraction weight WI'...W
／・・・・・・Way removed) B PA・Electrical sensor. Patent applicant Tanita Manufacturing Co., Ltd.

Claims (1)

[Claims] 1) A horizontal rod (2) is provided on the fulcrum (1), and this horizontal rod (2)
A balance weight (W o ) is suspended on one end (2a), and the other end (2b) has a plate (3).The plate holder is a rod (4).
is engaged with a stay (6) horizontally suspended from a fulcrum (5), and this plate holder is mounted on a mounting table (7) fixed to a rod (4) with a plurality of adjustable weights (Wl...・Ws・・
) is placed and the horizontal rod is in a balanced state, the plate holder places the moving part of the electric sensor (B) on the extension of the rod (4) or on the extension of the horizontal rod (2). An addition/subtraction type electronic scale is provided with a means for converting the amount of electricity generated by the fixed electric sensor (B) into a weight value, and the weight conversion value is digitally displayed on a display section (22). . 2) The electric sensor (B) is mounted on two parallel flat plates (17), and the movable electrode plate (17b) that moves opposite to the fixed electrode plate (17a) is held by the plate holder, which is an extension of the rod (4). An adjustable electronic scale according to claim 1, which is fixed on an extension of the upper or horizontal rod (2). 3) The electric sensor (B) detects the coil (18) and this coil (
18) It is formed of a core (19) whose inner part is oriented in the axial direction, and either the wire ring (18) or the core (19) is fixed to the base (1f), and the other moving part is the core. (19
) or wire ring (18) is fixed on an extension of the plate holder (4) or on an extension of the horizontal rod (2). 4) The most significant digit (22a) of the display section (22) indicates the way l− removed from the addition/division weights (Ws...W6...)
The weight of (w+'...W s'...) is switched and displayed separately or within the same display section (22) via the switch (23), and the lower digit (22b) is displayed as the electric sensor (B). □ An addition/subtraction type electronic scale according to claims 1, 2, and 3, in which the amount of electricity generated in ) is converted into a weight value and displayed.