JPS58178224A - Weight measuring device - Google Patents

Abstract

PURPOSE:To obtain the highly accurate measuring device, by utilizing the Pascal's principle, utilizing the pressure of fluid, thereby keeping balance and eliminating shift errors perfectly. CONSTITUTION:When a material to be measured is mounted on an upper pan, the load is transmitted to the fluid through a pressure applying plate and compresses the fluid. When the pressure of the fluid at the side of a fluid pressure coupling part is increased, a shielding plate 6 is pushed up, and the amount of light reaching a light receiving element 8 from a light emitting element 7 is decreased. An inverted triangle shaped window part is provided in the shielding plate 6. The amount of movement of the shielding plate is detected as the change in the amount of received light. The output of the light receiving element 8 is converted into the time change by a V-F converter 11 and an F-T converter 12, and the result is inputted to a microcomputer operating circuit 13. The microcomputer operating circuit 13 determines the pump driving time for a pump driving circuit 14 based on the signal change, controls ON and OFF of a pressure pump or its driving time, and keeps the shielding plate 6 at a specified position. In the microcomputer operating circuit 13, the weight value is computed, and the weight is didplayed by a display part 16 in a display circuit 15.

Description

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

Conventionally, for example, food items and mail items at home, etc., etc.
There are many products that use a donkey-pal mechanism and spring elasticity, and an electromagnetic force balance type is used for scientific top plate peelers.

Figure 1 shows an example of the configuration of an electromagnetically balanced needle electric device.
The balance of the members is maintained by controlling the energization to υ by the members that make up the pal mechanism, and the amount of energization to force 1 is converted into a weight value using the weight value detection signal at that time and 1~ and displayed. It is something to do.

As shown above (7,@-1), the advantages of heavy equipment include small fluctuations in indicated values, fast response to loads, and high accuracy, but on the other hand, 1jAFjL dependence. Disadvantages include the fact that the A-D converter requires precision, which increases the cost, that there are many moving parts, and that there is an eccentricity error.Among these, what is an eccentricity error? , refers to the fact that when measuring with an object placed on the upper plate, there is a difference in the single weight value depending on the position of the object.
This is the most important issue in VC. Originally, the donkey pal mechanism was used to eliminate eccentricity errors, but its effect is only in one direction, and for eccentricity in the right angle direction, it is theoretically possible to eliminate eccentricity errors. It was not possible to eliminate it completely.

The present invention was proposed in response to the above points, and is based on the property of fluids (A
The purpose of the present invention is to completely eliminate eccentricity errors and provide a weighing device with high accuracy by using the skull's original ml) and maintaining balance using fluid pressure.

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

Figures 2 to 4 show an embodiment of the present invention. Figure 2 is a mechanical configuration diagram of the weighing device, Figure 3 is a configuration diagram of the signal processing section, and Figure 4 is a detection diagram. FIG.

To explain the configuration in FIG. 2, the inside of the pipe 5 is filled with a fluid 4 such as transparent oil, a pressure pump 9 is connected to one end, and an upper plate 1 and a pressure plate are connected to the other end. 2. A rope compression section consisting of a seal 3 and the like is provided. Nine, in the middle of the conduit 5, there is a bell plate 6 which is movable with the movement of the fluid and has an inverted triangular window part, and the detection cord is placed between the pipe plate 6. 7. Light receiving elements 8 are provided facing each other.

Note that the pipe line within the range of movement of the transport plate 6 is made of a transparent material such as an I-rus pipe.

Figure 3 shows the configuration of the signal processing section in a block diagram.
is connected, and the output end of the light receiving element 8 is connected to a V-F converter 11,
The microcomputer arithmetic circuit 130 is sequentially connected to the F-T converter.
-C is connected to the input port. In addition, the display unit 1 is connected to the output port of the microcomputer arithmetic circuit 13 via a display circuit 15.
6 is connected to send signals to the pump drive circuit 14. Here, the pump drive circuit 14 controls the pressurizing pump 9 shown in FIG. 2 as appropriate in accordance with the output of the microcomputer calculation circuit 13.

In operation, when an object to be measured is placed on the upper plate 1, its load is transmitted to the fluid 4 via the pressure plate 2, compressing the fluid 4. In this case, the force that compresses the fluid depends only on the load (depending on the properties of the fluid), and even if the upper Ill is eccentrically placed, the influence will not be strong enough.Now, due to the load, the fluid As the pressure of the compressed fluid increases, the layer shield 86 is pushed upwards, and the amount of light that is suitable from the detection probe 7 to the light receiving element 8 decreases. Figure 4 (a), (b)
2 shows the change in the amount of light passing through depending on the position of the door plate 60, but since the door plate 6 has an inverted triangular window, the amount of movement of the door plate changes the amount of light received. Detected as .

In FIG. 3, the output of the light-receiving element 8 is converted by a V-F converter 11 into a change in the same wave number F, and then converted into a change in time T by an F-T converter 12. and is input to the microcomputer calculation circuit 13. Then, the microcomputer calculation circuit I3 determines the four-ring drive time of the l/y7' drive circuit 14 based on this signal change, and controls the on/off and drive time of the pressurizing pump to maintain fluid balance. In other words, it operates to keep the sliding plate 6 in a fixed position. On the other hand, microcomputer calculation circuit 1
3, the weight value is calculated using the signal sent from the FT converter, and the display circuit 15 and the display section 16 perform the weight measurement. Note that the configuration of the signal processing section is not limited to that shown in Fig. 3, and other configurations may also be used. death,
In order to recover from this problem, a simple configuration in which the pressurizing pump is turned on and off may be considered. At this time, the weight value can be calculated by WI from the ON time of the pressurizing pump.

No. 514 is the external appearance of the scale body shown for reference.

The explanation will be omitted.

As shown in 9 above, in the weighing device 4 of the present invention, one end of the pipe filled with fluid is connected to a pressurizing pump, and the other end of the pipe is connected to a fluid compressor that transmits the load on the upper plate to the fluid. 4, and a shielding plate that is movable according to the movement of the fluid is provided in the middle of the pipe,
A light-emitting element and a light-receiving element are provided facing each other with a space between them, and the movement of the fluid is detected as a change in the amount of light received by the light-receiving element, and the pressure 4yf is controlled to maintain the balance of the fluid.
Since the detection signal or (/g control signal) is converted into a weight value and displayed, the eccentricity error can be completely eliminated, and a weighing device with high accuracy can be provided.

[Brief explanation of drawings]

The explanation is shown in Figure 5, and Figure 5 is a reference diagram showing the external appearance of the scale. 1... Upper plate, 2... Pressure plate, 3-Seal, 4-fi
Body, 5... Pipe line, 6... Subject plate, 7... Light emitting element, 8... Light receiving element, 9... Pressure pump, 10.
... constant voltage circuit for light emitting element, 11... V-F converter,
12...F-Ding exchanger, 13-...Microcomputer arithmetic circuit, 14...I amplifier drive circuit, 15...Display circuit, 1
6...Display section. Figure 3 Figure 5 110-

Claims (1)

[Claims] One end of the pipe line filled with fluid is connected to a pressure pump KJI, and a fluid compression part is provided at the other end of the pipe line to transmit a zero load to the fluid, and as the fluid moves, a fluid compressor is provided at the other end of the pipe line. A movable glass plate is provided, a light emitting element and a light receiving element are provided facing each other with the plate in between, and the movement of the fluid is detected as a change in the amount of light received by the light receiving element to control the pressurization. It is characterized by maintaining the balance of the fluid and converting the detection signal or 4-ring control signal into a weight value and displaying it.