JPH0641876B2 - Weight discriminator - Google Patents

Description

The present invention relates to a device for comparing the weight of an article with a preset weight to determine which of a plurality of ranks the article corresponds to.

<Prior Art> Conventionally, as the above-mentioned discrimination device, for example, FIGS.
There was something like the one shown in the figure. This is the infeed conveyor 2
The container 4 is sent to the weighing conveyor 6 by
After measuring the weight of the container 4 and tare the container 4, the article is supplied from the hopper 8 to the container 4, the actual weight of the article is measured, and the actual weight is measured by a discriminating device (not shown) to determine the allowable lower limit value LL and Each is compared with the allowable upper limit value UL, and when the actual weight is smaller than the allowable lower limit value LL, it is lightweight, when the actual weight is between the allowable lower limit value LL and the allowable upper limit value UL, and the actual weight is the allowable upper limit value UL. When it is larger than the above, it is judged as an excessive amount, and after the container 4 is sent out by the sending conveyor 10, the articles are sorted based on the above judgment result.

FIG. 5 is a flow chart of discrimination by a discrimination device (not shown). First, the actual weight W of the article in the container 4 is read from the weighing conveyor 6 (step S1), and whether the actual weight W is smaller than the allowable lower limit value LL. Judge (step S2), YES
If so, the light weight relay is turned on, and the appropriate amount and excess amount relays are turned off (step S3). Step S2
If the determination is NO, it is determined whether the actual weight W is smaller than the allowable upper limit value UL (step S4). If the determination is YES, the appropriate amount relay is turned on, and the light weight and excess amount relays are turned off (step S5). If the determination in step S3 is NO, the overload relay is turned on and the light weight and proper amount relays are turned off (step S6). Items are sorted according to the ON / OFF state of each of these relays, and an alarm is issued when the lightweight or excessive relay is on.

<Problems to be Solved by the Invention> However, in the apparatus as described above, when the container 4 is not yet sent to the weighing conveyor 6, or when the container 4 is sent to the weighing conveyor 6, Since the weighing signal of the weighing conveyor 6 is smaller than the allowable lower limit value LL when no articles are supplied to the container 4, as shown in FIG. 6, the lightweight relay is turned on and an alarm is issued. Atsuta Further, in such an apparatus, in order to prevent the articles from being supplied to the same container 4 over a plurality of times and the plurality of containers 4 to be fed onto the weighing conveyor 6, It is necessary to provide a photoelectric detector 6 to detect that the container 4 is sent out from the weighing conveyor 6 and a new container 4 is sent to the weighing conveyor 6, and the configuration becomes complicated. Atsuta Further, this apparatus feeds the container 4 to the weighing conveyor 6 by the feed-in conveyor 2, tares the container 4 on the weighing conveyor 6, and then supplies the article to the container 4 on the weighing conveyor 6. Therefore, accurate weighing cannot be performed unless the supply of the articles is started after confirming that the taring has been completed. Therefore, the optical detector detects that the container 4 is placed on the weighing conveyor 6, and a timer or the like measures the elapse of a certain time from this detection, for example, the time from the detection to the completion of tare. There is a problem in that the configuration is complicated because the articles are supplied after the timekeeping is completed.

<Means for Solving Problems> In order to solve the above problems, the present invention provides a weighing means, a carrying-in means for carrying a tare into the weighing means, and the above-mentioned weighing means. A means for supplying an item to be weighed to the tare, a carrying-out means for carrying out the tare supplied with the item to be weighed from the weighing means, and a weighing signal from the weighing means is more than a first set weight signal. Comparing means for making the discrimination signal a light weight instruction state when it is small, and blocking for preventing the discrimination signal from being generated when the weighing signal is smaller than a second set weight signal preset to a value near zero of the weighing signal. Means and
And a detection unit that detects that the determination signal has changed from the blocking state to the lightweight instruction state and then to the blocking state again.

<Operation / Effect> According to the present invention, when the weighing signal is smaller than the second set weight signal, the blocking means prevents the determination signal from being generated. Therefore, at the stage where the tare is not sent to the weighing means, the discrimination signal is not generated. Further, when the generation of the discrimination signal is blocked, it can be seen that the tare has not been sent to the weighing means.Therefore, an optical detector conventionally provided to detect whether or not the tare has been sent. Is unnecessary, and the configuration can be simplified. Further, since the second set weight signal is set near zero, that is, smaller than the tare weight, when the tare is sent to the weighing means and tare is performed, the tare weight is weighed. The signal changes from zero to tare weight and back to zero. As a result, the determination signal changes from the generation-prevented state to the light weight instruction state, and again to the generation-prevented state. By detecting this change with the detection means, it can be seen that the tare has been sent to the weighing means and the tare has been completed.Therefore, while the tare is being performed, the tare on the weighing means is erroneously detected. Can prevent the supply of goods,
Conventionally, the optical detector, the timer, and the like, which have been necessary for detecting such tare subtraction, are unnecessary, and the configuration can be simplified.

<Example> In this example, similarly to the conventional one described above, an empty container is sent to a weighing conveyor by a feeding conveyor, tare is performed by the weighing conveyor, and then an article is supplied from a hopper to the container. , The actual weight of the article in the container is compared with the allowable lower limit value LL and the allowable upper limit value UL.

FIG. 2 is a block diagram of a device for discriminating this embodiment. An analog weighing signal from the weighing unit 12 of the weighing conveyor is converted into a digital weighing signal by the A / D converter 14,
It is supplied to the calculation unit 16.

The calculation unit 16 is composed of, for example, a microcomputer, and has a digital weight (D) corresponding to, for example, the weight of the container.
The digital weighing signal of the container is subtracted from the digital weighing signal when the article is supplied, that is, the tare is performed to calculate the actual weight W of the article, and the actual weight of the article is displayed on the display unit 18. Display W and container weight.

On the other hand, the allowable lower limit value LL, the allowable upper limit value UL, and the n weight are set in the arithmetic unit 16 using the numeric keypad 20. These have a relationship as shown in the lower part of FIG. 3, and in particular, n weight is the minimum weight unit that can be displayed on the display unit 18, for example, 1 g or 5
It is set to a value several times larger than g. This is to remove the influence of the zero change due to the disturbance or the zero change due to the article adhering to the container.

The calculation unit 16 calculates the actual weight W, the allowable lower limit value LL, and the allowable upper limit value U.
L and n weights are compared, and based on the results, the light weight / proper amount / overload display unit 22 including three lamps and the output unit 24 including the light weight, proper amount and overload relays are controlled.

The discrimination function of the arithmetic unit 16 will be described with reference to the flow chart of FIG. Since the function of obtaining the actual weight of the article is well known, detailed description is omitted. First, the actual weight W
Is less than or equal to n weight (step S10), and if NO, the N flag is set to "0" (step S11) and YES.
If so, the N flag is set to "1" (step S12). Then, it is judged whether the N flag is "1" (step S13), and Y
If it is ES, it turns off both the light weight, proper quantity and excess quantity relays (step S14). This state, that is, the discrimination signal blocking state is shown in a region A of FIG. As a result, no alarm is given, and none of the lamps of the light weight / appropriate / excessive quantity display section 22 is turned on.

If the determination in step S13 is NO, it is determined whether the actual weight is smaller than the allowable lower limit value LL (step S15). If this judgment is YES, the light weight relay is turned on, and the appropriate amount and the excessive amount relays are turned off (step S16). This state, that is, the light weight instruction state is shown in a region B of FIG. This gives an alarm. Subsequent to step S16, the lightweight lamp of the display unit 22 is turned on (step S17).

If the determination in step S15 is NO, it is determined whether the actual weight W is smaller than the allowable upper limit value UL (step S18). If this judgment is YES, the appropriate amount relay is turned on, and the light weight and excessive amount relays are turned off (step S19). This state is shown in the area C of FIG. There is no alarm in this state.
Subsequent to step S19, the appropriate amount lamp of the display unit 22 is turned on (step S20).

If the determination in step S18 is NO, the overload relay is turned on and the lightweight and proper amount relays are turned off (step S2
1). This state is shown in area D in FIG. An alarm will be issued in this state. Subsequent to step S21, the excessive amount lamp of the display unit 22 is turned on (step S22).

Although not shown in the figure, a light-weight relay and an overload relay are logically ORed to generate an alarm. Also, the presence or absence of articles on the weighing conveyor can be detected by taking the logical sum of the relays, and as described in the section of the effect,
It is possible to reliably detect that the tare is completed by detecting that the lightweight relay is turned from on to off and then turned off again.Therefore, it is possible to mistakenly feed the article to the tare while the tare is not finished. Can be prevented.

In the above embodiment, the actual weight W and the n weight are compared with each other, and then the actual weight W and the allowable lower limit value LL are compared with each other, but the order may be reversed. Further, although the actual weight W and the allowable upper limit value UL are compared at the end, they may be compared at the end. In addition, light weight, appropriate amount and overdose 3
Although the determination is made in stages, the determination may be made in two stages or four or more stages. Further, it is not necessarily limited to the case where the weight is measured by the weight conveyor.

[Brief description of drawings]

FIG. 1 is a flow chart of an embodiment of a weight discriminating apparatus according to the present invention, FIG. 2 is a block diagram of the embodiment, and FIG. 3 is a diagram showing ON / OFF states of respective relays of the embodiment, and FIG. Fig. 1 is a block diagram of an example of a conventional weight sorting device, Fig. 5 is a flow chart of the device, and Fig. 6 is an ON / OFF of each relay of the device.
It is a figure which shows an off state. 12 …… Weighing section, 16 …… Calculation section.

Claims (1)

[Claims] 1. A weighing means, a carrying-in means for carrying a tare into the weighing means, a means for supplying an article to be weighed to the tare on the weighing means, and a supply of the article to be weighed. Carrying-out means for carrying out the tare from the weighing means, comparing means for setting the determination signal to a light weight instruction state when the weighing signal from the weighing means is smaller than the first set weight signal, and the weighing signal Blocking means for blocking the discrimination signal when the weighing signal is smaller than the second preset weight signal preset to a value near zero, and a transition from the discrimination signal blocking state to the lightweight instruction state and again to the blocking state. A weight discriminating apparatus comprising: