JP4898493B2 - Weighing device - Google Patents

Description

  The present invention is a measuring device for separating a predetermined amount from an object to be weighed being transported in an irregular lump using a technique for measuring the mass of an object from the amount of X-ray transmission when irradiated with X-rays. About.

  For example, as shown in FIG. 8, a weighing device 100 that measures powder such as wheat flour or granular objects such as coffee beans includes a feeder 102 and a hopper 103 having a weighing function. Powder or granular object to be weighed 101 is supplied from the feeder 102 to the weighing hopper 103, and when the measured value by the measuring hopper 103 reaches a predetermined value, the supply from the feeder 102 is stopped and the weighing hopper 103 is dropped. The predetermined amount is separated.

Moreover, the following patent document 1 discloses an apparatus for performing weight measurement while conveying a free-flowing product (a bulk material). This device is a device for performing continuous weight measurement of a bulk material using a measuring device and determining a mass flow rate. Here, as shown in FIG. 9, the measuring device (measuring belt weighing supply means) 200 measures the weight of the bulk material 201 by a load cell 202.
JP-T-2006-518842

  However, in the conventional weighing device 100 as described above, as shown in FIG. 8, the object to be weighed 101 is supplied from the feeder 102 to the weighing hopper 103 and further weighed while accumulating the object to be weighed 101 in the weighing hopper 103. Therefore, it takes about 6 seconds to separate the object 101 by a predetermined amount. However, since this takes too much time, it is necessary to arrange a plurality of weighing devices 100 in order to increase the speed. However, there is a problem that the number of parts increases, the cost increases, and the size of the device increases. .

  In addition, the measuring device 200 (see FIG. 9) disclosed in Patent Document 1 can continuously measure the weight of the bulk material 201 being conveyed by measuring the weight with the load cell 202, It is very difficult to separate a predetermined amount from among them.

  Therefore, the present invention has been made in view of the above situation, and uses a technique for measuring the mass of an object from the amount of X-ray transmission, measures an object to be measured that is conveyed in an indeterminate shape, and An object of the present invention is to provide a weighing device that is simple and small in size by speeding up a predetermined amount by controlling the conveying means.

Next, means for solving the above problems will be described with reference to the drawings corresponding to the embodiments.
The weighing device according to claim 1 of the present invention comprises a conveying means 3 that conveys the object 2 to be weighed in an indeterminate shape in the conveying direction Y at a constant speed,
An X-ray generation source 11 that irradiates X-rays at a predetermined X-ray irradiation position with respect to the object 2 being transported by the transport means 3;
An X-ray sensor 12 which is disposed opposite to the X-ray generation source 11 and detects X-rays irradiated from the X-ray generation source 11 and transmitted through the object 2;
Wherein the mass of the objects to be weighed 2 based on X-ray transmission amount detected by the X-ray sensor 12 continuously metered, the metering value is controlled to stop the transport means 3 was reached a predetermined value The weighing object 2 after the measurement is dropped from the conveyance end portion of the conveying means 3, and the weighing object 2 after the weighing is separated from the weighing object 2, and then the conveying means 3 is reversely controlled to control the conveying means 3. Separating means for returning the separation end of the object 2 left on the top to the X-ray irradiation position ;
It is characterized by comprising.

The measuring device according to claim 2, wherein the separation unit compares the X-ray transmission amount detected by the X-ray sensor 12 with a predetermined threshold value, and performs reverse rotation control until the transmission amount becomes smaller than the threshold value. It is characterized in that.

The weighing device according to claim 3 , wherein the separating unit further includes a cutter 30 for separating the measured object 20 after the measurement that has reached a predetermined value from the object 2 (20). Yes.

The measuring device according to claim 4 , wherein the X-ray generation source 11 and the X-ray sensor 12 are configured such that the X-ray sensor 12 is positioned downstream in the transport direction Y with respect to the X-ray generation source 11. It is characterized by being opposed to each other.

The weighing device according to a fifth aspect is characterized in that the weighing device 1 according to the first to fourth aspects includes a plurality of the conveying means 3 and one X-ray generation source 11 which are independent from each other.

  According to the weighing device of the present invention, the X-ray sensor is used to measure the mass of the object to be weighed being transported as an indeterminate lump, and the predetermined amount is determined by controlling the transport of the transport means. The weighing of the object to be weighed and the predetermined amount after weighing can be performed in a series of transport operations, and high-speed processing becomes possible. For example, in the past, a processing time of about 6 seconds was required in order to distribute a predetermined amount of objects to be weighed, but this measuring device can shorten the time to about 1 second. Further, since the number of parts is small, the cost is not increased, and the entire apparatus can be configured simply and compactly.

  Also, for example, when the object to be weighed is a powder such as wheat flour or a granule such as coffee beans, the object to be weighed during transportation only by stopping the conveying means when the measured value by the X-ray sensor reaches a predetermined value. A predetermined amount can be separated from the object.

  Thereafter, the object to be weighed left on the conveying means is returned to the X-ray irradiation position by reversing the conveying means, and as a result, the next weighing can be started again from zero.

Embodiments of the present invention will be specifically described below with reference to the drawings.
FIG. 1 is a schematic perspective view showing a first embodiment of a weighing device according to the present invention, FIG. 2 is a plan view for explaining the principle of measuring the mass of an object to be weighed in the embodiment, and FIG. (A)-(d) is a side view which shows the isolation | separation operation | movement by the isolation | separation means of the embodiment.

  The weighing device according to the first embodiment is a device for weighing, for example, powders such as flour or granular objects 2 such as coffee beans so as to be separated by a predetermined amount, and is shown in FIG. As described above, the conveyance means 3, the X-ray generation source 11, the X-ray sensor 12, and the separation means are provided. It is transported at a constant speed in a predetermined transport direction Y.

  As shown in FIG. 1, the conveyor means 3 described above employs a conveyor (belt conveyor) in which a conveyor belt 5 is wound between two rollers 4 and 4 arranged side by side in the conveyance direction Y. . The belt conveyor 3 moves the conveyor belt 5 in the conveyance direction Y at a constant speed by rotating any of the rollers 4 by a drive motor (not shown). Further, the transport belt 5 forms a transport surface 5a for transporting the object 2 to be transported in the transport direction Y.

  The X-ray generation source 11 is installed above the conveyance end portion of the belt conveyor 3. Such an X-ray generation source 11 is generally not shown, but an X-ray tube for generating X-rays is generally immersed in insulating oil in a metal box, and the X-rays are directed downward (predetermined X-ray irradiation). Irradiate toward the position. In addition, the aspect of X-rays irradiated from this X-ray generation source 11 becomes a surface shape orthogonal to the conveyance direction Y of the belt conveyor 3, and the surface has comprised the substantially triangular shape extended downward.

  The X-ray sensor 12 is formed by arranging a plurality (about 200) of detection elements 13 linearly in a direction orthogonal to the conveying direction Y of the belt conveyor 3 (see FIG. 2). The X-ray sensor 12 is disposed opposite to the X-ray generation source 11 and is installed below the transport surface 5a of the belt conveyor 3 in the present embodiment. Each detection element 13 includes a photodiode and a scintillator disposed on the photodiode, although not shown. The X-ray sensor 12 further amplifies the output signal from each detection element 13, performs an A / D conversion, and a microcomputer that performs a later-described measurement operation based on the output signal from the analog processor. (Both not shown).

  Although not shown, the X-ray irradiation position including the X-ray generation source 11 and the X-ray sensor 12 is shielded to prevent X-ray leakage.

  The X-ray generation source 11 and the X-ray sensor 12 as described above are to be weighed when the object to be weighed 2 being transported on the transport surface 5a of the belt conveyor 3 is positioned at the X-ray irradiation position of the transport end portion. The object 2 is irradiated with X-rays from the X-ray generation source 11, the X-ray transmitted through the object 2 is converted into light by the scintillator of the X-ray sensor 12, and the light converted by the scintillator is a photodiode. Is received, converted into an electrical signal and output.

  As shown in FIG. 2, for example, when an object to be weighed 2 being conveyed on the conveyance surface 5 a is on the X-ray sensor 12, the detection elements 13 a and 13 c at both ends of the X-ray sensor 12 are not covered on the objects to be measured. Since the weighing object 2 does not exist, the X-ray transmission amount is large, and since the measurement object 2 exists on the detection element 13b near the center, the X-ray transmission amount is small. At this time, the X-ray detection amounts of the detection elements 13a and 13c are large, and the output from the corresponding analog processor is large. Further, the amount of X-ray detection by the detection element 13b is small, and the output from the corresponding analog processor is small. Therefore, the maximum value of the X-ray transmission amount determined as the object to be weighed 2 is set as a threshold value, and the object to be weighed 2 exists when the X-ray detection amount is smaller than this threshold value.

  In FIG. 2, the detection element 13a has an X-ray transmission amount larger than the threshold, the detection element 13b has an X-ray transmission amount smaller than the threshold, and the detection element 13c has an X-ray transmission amount larger than the threshold. As a result, the location of the object to be weighed 2 in the figure can be recognized based on the outputs of the detection elements 13 a to 13 c of the X-ray sensor 12.

  As described above, the output signal from the analog processor corresponding to each of the detection elements 13a to 13c of the X-ray sensor 12 is continuously applied to the measurement object 2 being conveyed at a constant speed by the belt conveyor 3. By processing by the computer, output signals for each continuous detection element 13 in the transport direction Y of the object to be weighed 2 and the direction orthogonal to the transport direction Y are obtained. Then, these output signals are transmitted to a control unit (not shown) provided in a separating unit to be described later, and are compared with the threshold value in the control unit to obtain the shape information of the object 2 to be weighed. Further, the control unit can obtain appearance information such as the diameter and area of the object 2 by calculation from these values, and can also obtain the mass of the object 2 to be weighed.

Next, an example of a method for measuring the mass of the object 2 to be measured based on the X-ray transmission amount will be described.
In general, the amount of X-ray transmission depends on the mass of an X-ray-transmitted object. On the transport surface 5a of the belt conveyor 3, if the X-ray transmission amount when the object 2 does not exist is I ₀ , the X-ray transmission amount when the object 2 exists is I and the mass is M, the following formula (1) is established.
I = I ₀ exp (−CM) (1)
(∵C is the transmission constant)

Therefore, the mass M is obtained by the following formula (2).
M = (1 / C) log (I ₀ / I) (2)

As a result, in the above-described detection of the appearance information, the X-ray transmission amount of the object to be measured 2 is obtained from the output signals that are smaller than the threshold among all the output signals corresponding to the position of the object to be measured 2 by the respective integrated values. Further, the mass M of the object 2 is obtained from the attenuation amount (I ₀ / I) of X-rays.

  Further, the separation means described above includes the control unit and is configured by conveyance control of the belt conveyor 3. Hereinafter, the separation operation by the belt conveyor 3 as the separation means in the present embodiment will be described with reference to FIG.

  As shown in FIG. 3A, the belt conveyor 3 conveys the object to be weighed 2 in an irregular lump shape in the conveyance direction Y at a constant speed. At this time, the object to be measured 2 sequentially passes through the X-ray irradiation position. At the X-ray irradiation position, the weighing of the object 2 by the X-ray sensor 12 is continuously performed (dynamic weighing).

  Next, as shown in FIG.3 (b), the belt conveyor 3 conveys the to-be-measured object 2 in the conveyance direction Y as it is, and the to-be-measured object 2 which finished the measurement by the X-ray sensor 12 in the X-ray irradiation position. The conveyor 3 is sequentially dropped from the conveyance end portion. At this time, for example, a storage container or the like is installed at the dropping point of the weighing object 2 to accommodate the falling weighing object 2. Thereafter, the belt conveyor 3 is controlled to stop when the measured value by the X-ray sensor 12 reaches a predetermined value.

  Next, as shown in FIG. 3C, the belt conveyor 3 is reversely controlled when a predetermined amount of the object to be weighed 2 falls from the conveyance end portion. Thereby, the conveyance surface 5a of the belt conveyor 3 moves by a predetermined amount (time or distance) in the direction opposite to the conveyance direction Y.

And as shown in FIG.3 (d), the belt conveyor 3 starts conveyance of the to-be-measured object 2 left on the conveyance surface 5a toward the conveyance direction Y again.
In addition, by performing the conveyance operation of the belt conveyor 3 as described above, a predetermined amount can be separated from the object 2 to be weighed.

  According to the first embodiment, the X-ray sensor 12 is used to measure the mass of the powder or granular object 2 being conveyed as an irregular lump, and to convey the belt. Since the predetermined amount is divided by controlling the stop 3 to stop, the weighing of the object 2 and the separation of the predetermined amount after weighing can be performed in a series of transport operations, and high-speed processing is possible. Become.

  Further, when the predetermined amount is separated, the belt conveyor 3 is reversed and the separation end of the object 2 left on the transport surface 5a returns to just before the X-ray irradiation position. As a result, the next weighing can be started again from zero.

Next, a second embodiment of the present invention will be described.
FIG. 4 is a schematic perspective view showing a second embodiment of the weighing device according to the present invention, and FIGS. 2A to 2D are side views showing the separating operation by the separating means of the embodiment.
Note that, in the second embodiment described below, the same reference numerals are given to the same or identical portions as those in the first embodiment described above, and the description thereof is omitted.

  The weighing device according to the second embodiment is a device for weighing, for example, a solid lump-like object to be weighed 2 (20) such as cheese in order to be separated by a predetermined amount.

  The separation means includes a cutter 30 (see FIG. 4) in addition to the conveyance control of the belt conveyor 3 described in the first embodiment. Hereinafter, the separation operation by the separation means will be described with reference to FIG.

  As shown in FIG. 5A, the belt conveyor 3 conveys an object to be weighed 20 that is an indeterminate lump shape long in the conveyance direction Y at a constant speed in the conveyance direction Y. At this time, the weighing object 20 sequentially passes through the X-ray irradiation position. At the X-ray irradiation position, the weighing of the object 20 by the X-ray sensor 12 is continuously performed (dynamic weighing).

  Next, as shown in FIG.5 (b), the belt conveyor 3 conveys the to-be-measured object 20 in the conveyance direction Y as it is, and of the to-be-measured object 2 which finished the measurement by the X-ray sensor 12 in the X-ray irradiation position. When the measured value reaches a predetermined value, stop control is performed and the measured value is divided by the cutter 30. Note that, for example, a storage container is installed at the fall point of the cut object to be weighed.

  Next, as shown in FIG. 5 (c), the belt conveyor 3 is reversely controlled when a predetermined amount of the weighing object 20 falls from the conveyance end portion. Thereby, the conveyance surface 5a of the belt conveyor 3 moves by a predetermined amount (time or distance) in the direction opposite to the conveyance direction Y.

And as shown in FIG.3 (d), the belt conveyor 3 starts conveyance of the to-be-measured object 20 left on the conveyance surface 5a toward the conveyance direction Y again.
In addition, a predetermined amount can be separated from the lump of the objects to be weighed 20 by continuously performing the conveying operation of the belt conveyor 3 and the cutting by the cutter 30 as described above.

  According to the second embodiment, the X-ray sensor 12 is used to measure the mass of the object 20 being conveyed in the form of an indefinite shape that is long in the conveying direction Y, and the belt conveyor 3 is Since the predetermined amount is separated by cutting with the cutter 30 at the same time as the stop control, as in the first embodiment described above, the weighing of the object 20 and the separation of the predetermined amount after the weighing are performed in a series of transport operations. It can be performed in the middle, and high-speed processing becomes possible.

  Further, when a predetermined amount is separated, the belt conveyor 3 is reversed and the separation end portion of the object 20 left on the transport surface 5a returns to just before the X-ray irradiation position. As a result, the next weighing can be started again from zero.

  In addition, as shown in FIG. 6, it is possible to further increase the speed by using a plurality of weighing devices 1 (belt conveyors 3) of the present invention side by side in a direction orthogonal to the transport direction Y. At this time, only one X-ray generation source 11 is required, and X-rays can be irradiated to the objects to be weighed 2 conveyed to all the belt conveyors 3 that move independently from each other without excess or deficiency, It also reduces costs.

  As shown in FIG. 7, the X-ray sensor 12 may be provided on the downstream side in the transport direction Y with respect to the X-ray generation source 11. As a result, the X-ray generation source 11 and the X-ray sensor 12 are opposed to each other obliquely, and the X-rays emitted from the X-ray generation source 11 are slightly inclined in the transport direction Y from the vertical. As a result, it becomes possible to irradiate X-rays along the inclined surface of the separation end of the object 2 as shown in the figure, and the next weighing is zeroed without the reverse control of the belt conveyor 3 as described above. You can start with.

1 is a perspective view showing a first embodiment of a weighing device according to the present invention. It is a top view for demonstrating the principle which measures the to-be-measured object in the embodiment. (A)-(d) is a side view which shows the isolation | separation operation | movement by the isolation | separation means of the embodiment. It is a perspective view which shows 2nd Embodiment of the weighing | measuring device by this invention. (A)-(d) is a side view which shows the isolation | separation operation | movement by the isolation | separation means of the embodiment. It is a perspective view which shows other embodiment. It is a partial side view which shows other embodiment. It is a perspective view which shows the conventional measuring device. It is a side view which shows the conventional measuring device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Weighing device 2 ... Object to be measured 3 ... Belt conveyor as conveyance means 11 ... X-ray generation source 12 ... X-ray sensor 30 ... Cutter Y ... Conveyance direction

Claims (5)

Transport means (3) for transporting the object to be weighed (2) that has become an indeterminate lump in the transport direction (Y) at a constant speed;
An X-ray generation source (11) for irradiating the object to be measured being conveyed by the conveying means with X-rays at a predetermined X-ray irradiation position ;
An X-ray sensor (12) disposed opposite to the X-ray generation source and detecting X-rays irradiated from the X-ray generation source and transmitted through the object to be measured;
Based on the amount of X-ray transmission detected by the X-ray sensor, the mass of the object to be weighed is continuously measured, and when the measured value reaches a predetermined value, the conveying means is stopped and controlled after the measurement. The object to be weighed left on the conveying means by dropping the object to be weighed from the conveyance end of the conveying means, separating the weighed object from the object to be weighed, and controlling the conveying means in reverse. Separation means for returning the separation end of the X-ray irradiation position to the X-ray irradiation position ;
A weighing apparatus comprising: The separation means compares the X-ray transmission amount detected by the X-ray sensor (12) with a predetermined threshold value, and performs reverse control until the transmission amount becomes smaller than the threshold value. Item 1. The weighing device according to item 1. The weighing according to claim 1 or 2 , wherein the separating means further comprises a cutter (30) for separating the weighed object that has reached a predetermined value from the object to be weighed (2). apparatus. The X-ray generation source (11) and the X-ray sensor (12) are disposed opposite to each other, with the X-ray sensor positioned on the downstream side in the transport direction (Y) with respect to the X-ray generation source. The weighing device according to any one of claims 1 to 3. The metering device of claim 1, wherein (1) are each an independent plurality of said conveying means (3), weighing devices you anda one of said X-ray source (11) .

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