JPH0224449B2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains] This invention measures the weight of foreign substances such as rocks mixed in root vegetables such as beets (sugar beets) and yams that are conveyed by a conveyor or the like. Concerning a measuring device.

[Prior art and its problems]

In general, freshly dug root vegetables contain a considerable amount of foreign matter such as stones, and they have approximately the same color but vary in size, and they are transported in large quantities in a short period of time. Despite this, the measurement of the weight of foreign objects is often left to visual inspection, which results in large errors and low reliability, so there is currently a strong desire for automation.

[Purpose of the invention]

This invention was made in view of these points,
To provide a measuring device capable of simply, quickly, and accurately measuring the weight of foreign substances mixed in root vegetables.

[Key points of the invention]

In this invention, when root vegetables or a foreign object collide with a predetermined plate-like member to generate an impact between them, the root vegetables and the foreign object have different frequency components due to the difference in their elastic modulus. Components in a predetermined frequency range corresponding to the above are extracted and integrated, and a weight having a proportional relationship thereto is calculated by conversion.

[Embodiments of the invention]

FIG. 1 is an external configuration diagram showing an embodiment of the present invention. In the same figure, 3 ₁ and 3 ₂ are conveyors,
Reference numeral 4 denotes a detection section, and 5 indicates a weight calculation display section. The detection section 4 is composed of a diaphragm (detection plate) 41, an elastic body 42 such as rubber or a spring, a mounting base 43, and the like.
Note that 1 is a root vegetable such as a beet, and 2 is a foreign object such as a stone.

FIG. 1A is a block diagram showing the internal configuration of FIG. 1. As shown in the figure, an impact detector 44 is provided inside the detection unit 4, while a weight calculation display unit 5 includes an amplifier 51, a filter 52 such as a high-pass filter, and a noise and base component removal circuit 53. , a linearizer 54, an integration circuit 55, a display section 56, and the like.

The functions and operations will be explained below with reference to these figures.

Root vegetables 1 containing foreign matter 2 are sent by a conveyor 3 ₁ , but since a detection unit 4 is arranged at a predetermined height at the end of the conveyor, root vegetables etc. fall onto a detection plate 41 . do. Due to this fall,
While an impact is generated between the detection plate 41 and the root vegetables 1 or the foreign object 2, the elastic body 42 is displaced. The vibration or impact sound caused by this impact is detected by the detector 44, and as the detection means, for example, a well-known vibration sensor such as a vibration accelerometer, a vibration velocity meter, or a vibration level meter, or an acoustic sensor such as a microphone may be used. Can be done. After the output from the detector 44 is amplified by an amplifier 51, only those having a frequency higher than a predetermined frequency are extracted by a predetermined filter 52 such as a high-pass filter. That is, root vegetables 1
Since the modulus of elasticity differs between foreign matter 2 such as stone and foreign matter 2, the output obtained via the detector 44 has a different frequency distribution as shown in FIG. provided. In addition, FIG. 2 is a characteristic diagram showing the relationship between the detector output and frequency, and FIG. 2 is an output waveform diagram of root vegetables and foreign matter, respectively. Filter 5
Since noise, base components, etc. are present in the component obtained through 2, the circuit 53 removes these components, and the linearizer 54 linearizes them. In other words, the detector output taken out through the filter 52 is based on the weight, as shown in FIG.
However, depending on the measurement range, it is expected that this linear relationship will break down, so linearization is performed to compensate for this, but it may be omitted depending on the case. Note that FIG. 3 is a characteristic diagram showing the relationship between detector output and weight. The output of this linearizer 54 is led to an integration circuit 55 and integrated, and the result is given to a display section 55 and displayed as appropriate. It should be noted that means for converting the integrated value into weight is provided as appropriate, so that the display unit 5
6 allows the total weight of foreign objects to be displayed.
According to this configuration, even if the root vegetables 1 and the foreign object 2 fall onto the detection plate 41 at the same time,
Since only the output of the foreign object 2 is extracted, it is possible to avoid errors caused by adding these outputs.

〔Effect of the invention〕

According to the present invention, the weight of a foreign object can be automatically measured using a simple circuit configuration that simply extracts and integrates frequency components higher than a predetermined frequency, so an advantage is that an extremely inexpensive measuring device can be provided. That's what you get. In addition, in such a configuration,
For example, even if root vegetables and a foreign object fall onto the detection plate at the same time, a signal can be accurately extracted from only the foreign object, resulting in an advantage of improved reliability. Therefore, when purchasing a predetermined amount of root vegetables, the total weight of foreign substances can be determined easily and accurately, allowing for proper commercial transactions.

[Brief explanation of drawings]

FIG. 1 is an external configuration diagram showing an embodiment of the present invention;
Figure 1A is a block diagram showing the internal configuration of Figure 1;
FIG. 2 is a characteristic diagram showing the relationship between frequency and detector output, and FIG. 3 is a characteristic diagram showing the relationship between weight and detector output. Code explanation, 1... Root vegetables, 2... Foreign matter, 3 ₁ ,
3 ₂ ... Conveyance conveyor, 4... Detection section, 5... Weight calculation display section, 41... Vibration plate (detection plate), 42
...Elastic body, 43...Mounting base, 44...Impact detector, 51...Amplifier, 52...Filter, 53...
... Noise etc. removal circuit, 54 ... Linearizer,
55...Integrator circuit, 56...Display section.

Claims (1)

[Scope of Claims] 1. In order to measure the weight of foreign substances while conveying root vegetables mixed with foreign substances by a conveying member, a plate-like member is provided with a step difference relative to at least the conveying member, and impact generating means that generates an impact when root vegetables or foreign objects fall on the plate-like member; detection means that detects the vibration frequency component of the impact; 1. A device for measuring the weight of foreign substances mixed in root vegetables, comprising an integrating means for integrating components, and converting the integration result into a weight.