JPS598792Y2 - Unsuitable interval article discharge device - Google Patents

Description

[Detailed description of the invention] This invention is useful for measuring the weight of objects to be measured (hereinafter referred to as workpieces) that are sent intermittently, such as in a weight sorter, when The present invention relates to a device for discharging workpieces sent at intervals as unsuitable interval workpieces.

2. Description of the Related Art Conventionally, in a device for measuring the weight of a workpiece that is intermittently sent by a conveyor or the like, a device as shown in FIG. 1 is used to perform measurement control.

FIG. 2 is a time chart of each part of FIG. 1.

That is, after the detection output of the workpiece detector 1 shown in FIG. 2a is converted into a rectangular wave as shown in FIG. 2b by the waveform shaping circuit 2, the time required for the double cut prevention timer 3 and the scale to stabilize The timers 3 and 4 are sequentially guided to a measurement waiting timer 4 having a set time corresponding to
The output shown in d is taken out.

The output of the timer 4 is led to a measurement command generation circuit 5, from which a measurement command signal shown in FIG. 2e is generated.

Here, once the timers 3 and 4 receive an input, they do not respond even if the next workpiece detection output is received until the time is up.

That is, the set times of timers 3 and 4 are determined depending on the type of work.

For example, in the case of a workpiece as shown in Fig. 3a, the workpiece detection output appears several times in succession as shown in Fig. 3b. In such a case, the setting time of the double-cut prevention timer 3 should be lengthened. There is a need.

On the other hand, in the case of an unstable workpiece such as a workpiece that is tall relative to its base area or a workpiece that contains liquid, as shown in Figure 3C,
The workpiece detection output is as shown in Figure d, but in such a case, it is necessary to lengthen the setting time of the measurement wait timer.

Therefore, when these timers are operating, there is a risk that even if the next work arrives, it will pass through without being weighed and will be sent to the stage as a non-defective work.

Conventionally, in order to avoid such unmeasured workpieces, the speed of the introducing conveyor is increased more than necessary to ensure that the workpieces are introduced into the weight measuring device at appropriate intervals, taking into account snags, slips, etc. A device is added to increase the height of the workpiece, or to keep the distance between the workpieces constant.

However, in the former method, it is necessary to increase the operating speed of the weight measuring device as the speed of the introduction conveyor is increased, which is undesirable because it deteriorates measurement accuracy.

On the other hand, the latter method of providing a constant interval device has the disadvantage that the system becomes complicated and large.

The present invention has been developed in view of the above-mentioned points, and by discharging workpieces sent at intervals of less than a certain value as unsuitable interval workpieces and preventing them from being sent to the subsequent stage, It is an object of the present invention to provide a device for discharging articles at inappropriate intervals, which prevents unmeasured workpieces from being sent to a subsequent stage of a weight measuring device without increasing the speed more than necessary or installing a workpiece spacing constant device. purpose.

The details of the present invention will be explained below with reference to the drawings.

FIG. 4 is a block diagram showing an embodiment of the present invention, and FIG. 5 is a time chart of each part of FIG.

In FIG. 4, reference numeral 11 denotes a workpiece detector consisting of a photoswitch or the like provided corresponding to the path of the workpiece, and generates a detection output every time the workpiece passes, as shown in FIG. 5a.

The detection output of the workpiece detector 11 is led to a waveform shaping circuit 12 consisting of a Schmitt circuit, for example, and converted into a rectangular wave as shown in FIG. As shown in FIG. 5C, it is delayed by a constant minute time lt.

The output of this delay circuit 13 is guided to a control circuit 14 together with the output of the waveform shaping circuit 12.

This control circuit 14 generates the reference pulse shown in FIG. In the circuit shown in FIG. 5e, which generates a reset pulse for the workpiece proper interval setting timer, this reset pulse is guided to the workpiece proper interval setting timer (workpiece proper interval signal generation circuit) 15.

This timer 15 is constructed using a CR time constant circuit, and its set time T is selected to correspond to the appropriate interval for the workpiece.

That is, FIG. 5f shows the output voltage waveform of the time constant circuit (voltage across the capacitor), and FIG. 5g shows the output waveform of the timer 15. After a time T has elapsed since the pulse is supplied, the output shown in FIG.

Therefore, depending on the output of the timer 15, it is possible to determine whether the work interval is an appropriate interval corresponding to the time T or an inappropriate interval shorter than T.

16 is a work interval discrimination circuit for making this discrimination;
It is determined whether or not there is an output from the timer 15 during the period of the verification pulse from the control circuit 14, and if there is, the output from the timer 15 is determined as shown in FIG.
The appropriate interval discrimination signal shown in FIG.

Among the outputs of the discrimination circuit 16, the appropriate interval discrimination signal is supplied to a weight measuring device (not shown) as a weight measurement command signal, and the improper interval discrimination signal is guided to the discharge gate control timer 17.

This timer 17 is configured using a CR time constant circuit like the timer 15, and its set time is selected to be equal to or greater than T.

FIG. 5J shows the output waveform of the time constant circuit, and FIG. 5K shows the output waveform of the timer 17.

That is, the timer 17 is reset by the inappropriate interval determination signal to generate an output, and the output is restored after a time period of T or more has elapsed since the last inappropriate interval determination signal was supplied.

The output of the timer 17 is supplied to the discharge gate 18 as a discharge command.

As a result, the discharge gate 18 opens with a delay of α during the output period of the timer 17, as shown in FIG.

As the discharge gate 18, a sorting gate added to the weight measuring device can be used as is.

The reason for providing the timer 17 is to open the discharge gate 18 when the workpieces at inappropriate intervals arrive continuously until the last workpiece is discharged.

Also, the discharge game l is α after the output of timer 17 is generated.
The opening is delayed by a certain amount of time, but this is to prevent the workpieces with the proper spacing from being discharged by the discharge gate 18 before that, and the time α is the time required for the workpieces with the proper spacing to pass through the sorting section.

As explained above with reference to one embodiment, according to the present invention, the interval between incoming workpieces is determined, and workpieces with an inappropriate interval smaller than the proper interval are discharged from the discharge gate, so that a weight measuring device can be used. It is possible to prevent workpieces that cannot be measured from being sent to the subsequent stage, and it is possible to bring about good results in quality control.

Moreover, since a small number of judgment circuits are installed in one workpiece detector that detects the passage of a workpiece, there is no deterioration in measurement accuracy, unlike the method of increasing the speed of the introduction conveyor, and there is no problem with the detection of workpieces. Compared to the method of providing a constant interval device, the system does not become more complicated or larger.

On the other hand, when a filling machine or the like is controlled by the output of a weight measuring device, if two workpieces are placed on the weight measuring device at the same time, an overweight output will generally occur, which will cause the above-mentioned control to be disturbed.

With conventional weight measuring devices, when two workpieces are loaded, if the workpieces are small, they are normally discharged as an excess amount, but the timing of the sorter's operation is determined by the first or second workpiece. Therefore, the first or second workpiece may flow to the non-defective side.

On the other hand, according to the present invention, such successive workpieces are discharged as workpieces at inappropriate intervals, so there is no possibility that defective workpieces will be judged as non-defective workpieces.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the structure of a conventional weight measuring device control device, Fig. 2 is a time chart to explain the operation of Fig. 1, and Fig. 3 shows the type of workpiece and the output waveform of the workpiece detector. FIG. 4 is a block diagram showing the structure of an inappropriately spaced article discharging device according to an embodiment of the present invention, and FIG. 5 is a time chart for explaining the operation of FIG. 4. . 11... Work detector, 12... Waveform shaping circuit, 13... Delay circuit, 14...
- Control circuit, 15... Work suitability interval setting timer, 16... Work interval discrimination circuit, 17...
...Discharge gate control timer, 18... Discharge gate.

Claims (1)

[Scope of utility model registration request] l article detectors that sequentially detect articles that arrive intermittently; and a delay circuit that has a manual terminal connected to the output terminal of the article detector and outputs an output signal of the article detector after a predetermined time delay. , two input terminals are individually connected to the output terminal of the article detector and the output terminal of the delay circuit, and a verification signal is created using the output of the article detector and the output of the delay circuit, and a first a control circuit which outputs a timer reset signal from a second output terminal which is activated at the timing of the output of the delay circuit; The input terminal of the time constant circuit that reaches a predetermined level after the passage of time corresponding to the interval is connected, and the next timer reset signal is input from the input point of the timer reset signal input from the second output terminal of the control circuit. an object to be measured proper spacing signal generation circuit that outputs a proper spacing signal when the predetermined level is reached before manual input; and two inputs to an output terminal of the signal generation circuit and a first output terminal of the control circuit. The ends are individually connected, and if a proper spacing signal is manually input from the object to be measured proper spacing signal generation circuit during a period when a verification signal is output from the first output terminal, it is determined that the articles are at the proper spacing. A weight measurement command signal is outputted from a first output terminal upon determination, and if only a verification signal is input, it is determined that the article has an inappropriate spacing, and an inappropriate spacing is determined from a second output terminal. It is connected to the output end of the workpiece interval determination circuit that outputs a signal and the output terminal of the workpiece interval determination circuit, and generates a discharge command for a predetermined time from the input of the inappropriate interval determination signal, and for a predetermined time from the input of the discharge command. 1. A device for discharging articles at inappropriate intervals, comprising: a discharge gate control means for opening a discharge gate for a measured object with a delay.