JPS5919817A - Automatic correcting device in weight measuring machine - Google Patents

Abstract

PURPOSE:To maintain high accuracy of a titled device so that it is not influenced by a temperature change and it can be corrected quickly and frequently, by providing an adjustment command circuit for generating a correcting instruction periodically or irregularly, and a correcting circuit which compares a measured output value with a set value by a weight load mechanism, and corrects measuring circuit so that they coincide. CONSTITUTION:When a weight lifting device 1 lowers a weight 2 and loads the weight 2 to a load cell 3, weight of the weight 2 is outputted to a digital voltmeter 6 through the load cell 3, an amplifier 4 and a synthesizing circuit 5, also is compared with a set value of a digital switch 8, which corresponds to reference weight of the weight 2 is stored in advance, by a comparator 7, its difference is inputted to an up/DN counter 9, a value corresponding to the difference is inputted to a D/A converter 10, and the digital voltmeter 6 is corrected so as to become equal to the set value. When the difference of the comparator 7 becomes zero, a difference zero signal is inputted to an adjustment command circuit 12, a correction completion command is inputted to a weight circuit 11 and weighing circuit 13, and the device enters into a non-load state and a weight measuring state by lifting the weight 2 and closing the opening and closing valve of a weighing tank 14, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic correction device for measurement errors in a weight measuring machine that measures the weight of powder or granular material in a weighing tank.

Conventional weighing machines measure the weight of the weighing tank using a load cell.
The detection signal of the load cell was amplified by an intensifier and displayed in digital volts. However, with this device, changes in stiffness and span occur due to changes in temperature (the weight display on the digital voltmeter and the actual W fit do not match. This is a load cell.

This is thought to be caused by the temperature characteristics of the amplifier, digital voltmeter, etc. due to temperature changes. According to operational data, span fluctuations reached 0.02%/°C due to temperature changes, resulting in a total decrease of 1 J/i degree.

To correct this, stop the weight measurement, read out the object in the weighing tank, set the tare weight to zero, and then check.

The weight was manually placed on the ++f volume tank, and the span adjuster of the amplifier was used to compensate. That one? Not only does it take a lot of effort and time, but it also has the drawback of having to stop the four measuring machines.

Wood shavings 6^ eliminates these drawbacks, allows automatic correction, unmanned operation, and shortens the downtime for correction.
Moreover, it is an object of the present invention to provide an automatic correction device P2 which can be used as a nail axillary a1 measurement device with a high 4 degree angle.

The gist of this Toga is that the 71tjk of the itilt tank is measured periodically and irregularly using a built-in timer or 81-claw counter in a weight measuring device that measures the 71tjk of the itilt tank using a weighing scale such as a load cell. Adjustment 1M command circuit that generates a correction command in silos, and correction command 1 of the same n'/a adjustment command circuit
, 1 by ilt hl; A weight loading mechanism that loads a standard weight on the meter and is in an unloaded state during measurement, and a weight loading mechanism that places a needle 71 on the meter. 81 measurement output 11a and the set value of the open weight, and a correction circuit that corrects the R1 measurement circuit of the weighing scale so that the measurement output 111- matches the set value. r+li positive device button device.

Hereinafter, the present invention will be specifically explained using examples.

In this example, a load cell is used as the lt11 meter, and the beam of the load cell is,! I (This is an example that is equipped with a weight lifting device that can load a semi-weight, and has a circuit that displays the value of the load cell with a digital voltmeter and compares it with a set value for correction.

81-claw tank (in the former version of 14-weight), it was a standard claw-style gate-shaped weight that was placed on the lifting platform of the same weight lifting device without making the dispensing device (1). Beam (3)' of load cell (3) with (2) as a lifting shape 11
Float and stand still without applying any load. At this time, measurement tank 0
The weight of → is sensed by a load cell (3), passed through an amplifier (4), two composite circuits (5), and displayed by a digital voltmeter (6).

Next, the built-in timer or measurement counter (not shown) operates to periodically or irregularly operate the adjustment command circuit θ, and issues a correction command. The R1 amount stop signal is issued, the metering is stopped, and the objects in the 111 t tank are discharged, the bag claw is set to zero, and the digital voltmeter ( 6) output, M amount.

After confirming that no. ) is applied to the load cell (3). Then, the weight of the weight (2) is outputted to the digital voltmeter (6) via the load cell (3), multiplier (4), 1 synthesis circuit (5), and the weight equivalent to the reference weight of the weight (2) is output to the digital voltmeter (6). The set value of the digital switch (8) stored in advance is compared with the combination value (7), and the up/DN counter (9)
), the value corresponding to the difference is input to D/A converter 0 (fist), and D/A converter θ[ν
Correct the digital voltmeter (6) so that it is equal to the set value. As a result, when the difference of the comparator (7) becomes zero, the zero difference signal is input to the adjustment command circuit 00, and a correction completion command is sent to the weight lifting circuit 00. Measuring circuit θ1
is input, the weight (2) is raised to a non-load state, and the on-off valve OQ of weighing tank 0→ is closed to enter the weight measurement system.

In addition, in Figure 2 (11 is the measuring tank (rare hanging rod, (119)
010 is the opening/closing valve of the measuring tank, θ is the hopper, and 010 is the opening/closing valve of -.

Here, the weight lifting device (1) is driven by operating a solenoid valve in response to an electric control signal, using air pressure, or by a solenoid magnet, a motor, or the like.

Further, the contact surface between the molecule fl (2) and the load cell beam is processed so that the weight load is averaged perpendicularly to the beam (3)'.

As mentioned above, by equipping a weight measuring machine with Tsutomaki Ki's automatic correction device, it is not affected by temperature changes and has improved accuracy. There is a desire to be able to make corrections quickly and many times without having to do so, to be able to maintain a high 91 degrees, to reduce downtime of the machine, and to increase the total σtjl capacity.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the automatic correction device in the polar concave weight measuring machine, Fig. 2 is a front view showing the Nt and fi measuring machine of this embodiment, and i! FIG. 08 is a sectional view taken along the line I-■ in FIG. 2. (1) Two-weight lifting device (2) Two-weight lifting device (3): Load cell (3): Beam (6); Digital voltmeter (7): Converter (8): Digital switch θ■: Weight lifting circuit 0 pier: Adjustment Command circuit θ: Measuring circuit Q: Measuring tank Fig. 1 Fig. 3

Claims (1)

[Claims] 1) In a weight measuring machine that electrically measures the weight of a weighing tank using a weighing scale such as a load cell, this is the same as the adjustment command circuit that issues correction commands periodically or irregularly using a built-in timer or counting counter. Weight load 11t7 is loaded with a standard weight on the weighing scale by the correction command signal of the adjustment command circuit, and in the weighing machine IIJ, -C is in the non-load state P3, and the reference weight is loaded on the weighing scale by the same weight loading machine. An automatic correction device for a weight measuring machine comprising a correction circuit that compares the measured output value of a weight with the set value of the same reference weight and corrects the old weight measurement circuit so that the measured output value matches the set value.