JP2017009517A - Conveying and weighing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conveying and weighing device more suitable for achieving high-speed weighing than a conventional one.SOLUTION: In a weighing conveyer 30 as a conveying and weighing device, an article 100 as an object to be weighed is laid on two weighing units 30a, 30b at the substantially same timing, and is supported in cooperation with the weighing units 30a, 30b. If, for example, this state is viewed from an upstream side, an added load F1 to the one weighing unit 30a is transmitted to a load cell 34a as a load sensor in a vertically linear manner, so that unnecessary force such as moment is not generated. This contributes to improvement of rigidity and reduction in weight of the weighing unit 30a. The same is true on the other weighing unit 30b. As the whole weighing conveyer 30, two spring systems which are the weighing units 30a, 30b are in a state of being connected in parallel with each other, so that a spring constant is increased. Thus, natural frequency of the whole weighing conveyer 30 is increased and the weighing conveyer 30 becomes suitable for high-speed weighing.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a transport and weighing device that measures the weight of an article while transporting the article to be weighed.

  This type of conveyance and weighing device is applied to an application requiring high-speed weighing such as an automatic weight sorter. In such an application, in order to realize high-speed weighing, an article support base that supports an article as an object to be weighed, and a load that supports the article support base and is transmitted to itself through the article support base. It is necessary to increase the natural frequency of a weighing unit including a load sensor that outputs a load signal according to the above. In order to increase the natural frequency of the measuring unit, for example, measures such as improving the rigidity of the measuring unit, measuring the measuring unit, and increasing the spring constant of the measuring unit can be considered. Patent Document 1 discloses an example of a transport and weighing device in which these measures are taken.

  According to the prior art disclosed in this Patent Document 1, a weighing conveyor as a conveying and weighing device is provided with a pair of (two) chain guides as article support stands provided so as to extend in parallel with each other. A weighing platform, a weight sensor as a load sensor that supports the pair of weighing platforms, and a pair of chains as endless traveling bodies that run on the pair of weighing platforms along respective chain guides. Yes. By placing the article so as to straddle the pair of chains, the article is transported on the pair of weighing platforms in accordance with the pair of traveling chains. Then, based on a load signal that is an output signal of the weight sensor when the article is being conveyed on the pair of weighing tables, the weight of the article is obtained, that is, the weight is measured.

  Here, although not specified in Patent Document 1, each weighing platform is, for example, one metal plate formed (processed) in a substantially rectangular parallelepiped shape, and its vertical dimension is particularly large. As a result, the rigidity against the force acting in the vertical direction, that is, the load, is improved, and as a result, the rigidity of the entire measuring unit including the measuring table is improved. Each chain is driven by appropriate driving means including, for example, a sprocket and a motor. This driving means is provided separately from the measuring unit, and so to speak, is directly attached to the measuring unit. Not. Therefore, the weight of the entire measuring unit can be reduced accordingly. Furthermore, for example, a load cell having a relatively large rated capacity, in other words, a load cell having a large spring constant, is adopted as the weight sensor, so that the spring constant of the entire measuring unit including the weight sensor can be increased. As described above, according to the prior art, since the rigidity of the entire measuring unit is improved, the weight of the entire measuring unit is reduced, and the spring constant of the entire measuring unit is increased, it is suitable for realizing high-speed measurement.

  In the prior art, a feeding conveyor is provided in front of the weighing conveyor. First, the articles are supplied onto the infeed conveyor, and then transferred from the infeed conveyor onto the weighing conveyor. The infeed conveyor and the weighing conveyor have substantially the same height. This reduces the impact on the weighing conveyor when the article is transferred from the feeding conveyor onto the weighing conveyor. In addition, a delivery conveyor is provided after the weighing conveyor. Then, the article after the weight measurement by the weighing conveyor is transferred from the weighing conveyor to the delivery conveyor. The weighing conveyor and the delivery conveyor are also at the same height. This reduces the impact on the weighing conveyor when the article is transferred from the weighing conveyor onto the delivery conveyor. Furthermore, in the prior art, supply / conveying means for supplying articles on the feeding conveyor and removing the articles from the feeding conveyor is provided. Appropriate measures are taken to reduce the impact when the article is supplied onto the infeed conveyor by the supply / conveyance means and when the article is removed from the delivery conveyor by the supply / conveyance means. Has been.

JP 2003-126787 A

  By the way, although it is difficult to understand from Patent Document 1, in the prior art disclosed in Patent Document 1, a pair of weighing platforms are supported by a single weight sensor common to them. When this state is viewed from, for example, the upstream side (or the downstream side) in the article conveyance direction, the state is as shown in FIG. Note that FIG. 8 focuses only on the weighing conveyor, and in FIG. 8, illustration of elements other than the weighing conveyor such as the above-described feeding conveyor and feeding conveyor is omitted. In FIG. 8, a pair of elements 1a and 1b denoted by reference numerals 1a and 1b is a pair of weighing platforms. The substantially concave elements 2a and 2b formed on the respective upper portions of the pair of weighing platforms 1a and 1b are chain guides. Further, a pair of elements 3a and 3b engaged with the chain guides 2a and 2b, specifically, the lower portions of the chain guides 2a and 2b are accommodated, respectively, are a pair of chains. An element indicated by a broken line 4 so as to straddle the pair of chains 3a and 3b is an article.

  As shown in FIG. 8, the pair of weighing platforms 1a and 1b has an appropriate size in the direction horizontally traversing the conveying direction of the article 4 (left and right direction in FIG. 8), that is, in the width direction of the weighing conveyor. The connecting members 5 are connected to each other. The connecting member 5 is an appropriate part of the weight sensor (not shown in FIG. 8) via an appropriate connecting member 6 extending in the vertical direction, for example, at the central part in the width direction of the weighing conveyor. Is bound to. In other words, each weighing platform 1 a and 1 b is supported by the weight sensor via the connecting member 5 and the coupling member 6.

  Here, when the article 4 is transported on the weighing platforms 1a and 1b, loads F1 'and F2' including the weight of the article 4 are applied to the weighing platforms 1a and 1b. These loads F1 ′ and F2 ′ are transmitted to the weight sensor via the connecting member 5 and the connecting member 6, and in particular, the central portion of the connecting member 5 is a fulcrum for the connecting member 5. Moments M1 ′ (= L ′ × F1 ′) and M2 ′ (depending on the horizontal distances L ′ and L ′ from each of the load F1 ′ and F2 ′ to the application portions of the respective loads F1 ′ and F2 ′ = L ′ × F2 ′) acts. For this reason, the connecting member 5 is required to have such a high rigidity that it can sufficiently withstand these moments M1 'and M2'. Also, each weighing platform 1a and 1b is required to have a correspondingly high rigidity. However, if the rigidity of each of the weighing platforms 1a and 1b and the connecting member 5 is improved, these weights naturally increase, and consequently the weight of the entire weighing unit increases. This causes a decrease in the natural frequency of the weighing unit, which is inconvenient for realizing high-speed weighing. On the other hand, if it is going to suppress the increase in the weight of each weighing platform 1a and 1b and the connection member 5, naturally these rigidity will become low. This also causes a decrease in the natural frequency of the weighing unit, which is also inconvenient for realizing high-speed weighing. Further, the fact that the rigidity of each of the weighing platforms 1a and 1b and the connecting member 5 is low means that the spring constant is small when they are viewed as one spring system. For example, as shown in FIG. 9, the spring system 7 including the weighing platforms 1a and 1b and the connecting member 5 is connected in series to the weight sensor, and therefore the spring constant k1 ′ of the spring system 7 is connected. Is small, even if a load cell having a large spring constant k2 ′ (rated capacity) is adopted as the weight sensor as described above, the spring constant K ′ of the entire measuring unit is K = {k1 ′ · k2 ′} / { k1 ′ + k2 ′}, which is smaller. This also causes a decrease in the natural frequency of the weighing unit, which is inconvenient for realizing high-speed weighing.

  In short, the conventional technology still has disadvantages in realizing high-speed weighing.

  Therefore, an object of the present invention is to provide a transport weighing device that is more suitable for realizing high-speed weighing than before.

  In order to achieve this object, the present invention provides a plurality of article support bases, feeding means, a plurality of load sensors, And a weight calculation device. Among these, the plurality of article support bases are provided in parallel with the article conveyance direction, and support one article in a conveyance state in cooperation with each other. The feeding means is provided in front of each article support base in the article transport direction, and sends the article onto each article support base. At this time, the article is fed onto each article support base so as to get on each article support stage at substantially the same timing. Further, the plurality of load sensors are individually provided for each article support base, and support the corresponding article support base and respond to a load transmitted to itself via the corresponding article support base. Output load signal. The weight calculation means obtains the weight of the article based on each load signal output from each load sensor. Here, for each combination of the article support table and the corresponding load sensor, the article is transported until the load including the weight of the article on the article support table reaches the load sensor via the article support table. The load sensor is provided directly below the article support so as to transmit on a vertical plane along the direction.

  That is, according to the present invention, one weighing unit is constituted by a combination of each article support base and a load sensor corresponding to the article support table, that is, a plurality of weighing units are provided. Each of these weighing units is arranged in parallel with the conveyance direction of the article. In addition, a feeding means is provided in front of each weighing unit, and articles are fed onto the weighing units by the feeding means. At this time, the article gets on each weighing unit at substantially the same timing. Then, the articles loaded on the respective weighing units are supported in cooperation by the respective weighing units, strictly, by the respective article support bases of the respective weighing units. And based on the output signal of each weighing unit when this article is supported in cooperation by each weighing unit, strictly, each load signal output from each load sensor of each weighing unit, The weight calculation means obtains the weight of the article.

  Here, when attention is paid to each weighing unit, a load sensor is provided immediately below the article support. Then, the load including the weight of the article on the article support table is transmitted on one vertical plane along the conveyance direction of the article until it reaches the load sensor via the article support table. In other words, the transmission path of the load is on the vertical plane. Furthermore, in other words, the load transmission path when viewed from the upstream side or the downstream side in the conveyance direction of the article is a vertical line. Therefore, unlike the above-described prior art, moments M1 'and M2' as shown in FIG. 8 do not occur. For this reason, in particular, the article support base can have sufficient rigidity even if it has a relatively simple structure, that is, light weight. Further, since the connecting member 5 as shown in FIG. 8 is not necessary, the weight of the measuring unit can be further reduced, and the rigidity of the measuring unit can be further improved. In addition, when an article is sent onto each weighing unit by the feeding means, the article gets on each weighing unit at substantially the same timing. Therefore, for example, when the distribution of the weight (mass) of the article in a direction transverse to the conveyance direction of the article is substantially uniform, the load due to the weight of the article is approximately the same timing and the same volume ratio in each weighing unit. As a result, the load signals, which are output signals of the respective measuring units, exhibit substantially the same characteristics, and in detail, exhibit substantially the same amplitude, frequency, and phase. In addition, when each measuring unit is viewed as one spring system, a plurality of spring systems including a plurality of measuring units are connected in parallel to each other. Therefore, when each of these spring systems is viewed as a whole, the overall spring constant is increased.

  Each weighing unit may include a substantially string-like endless traveling body that travels on a support portion of an article on the article support base. In this case, each endless traveling body of each weighing unit travels in the same direction and at the same speed. According to this configuration, the article is placed so as to straddle over each endless traveling body, so that the article is transported on each weighing unit in association with each traveling endless traveling body. Each article is supported on each article support (support part).

  In addition, the article may be conveyed by sliding on each article support base of each weighing unit, that is, each weighing unit may be configured to be so.

  As described above, according to the present invention, a plurality of weighing units are provided, and an article as an object to be weighed gets on each weighing unit at approximately the same timing, and cooperates with each weighing unit. Supported. Each weighing unit is improved in rigidity and weight compared to the weighing unit in the above-described prior art. Further, when each measuring section is viewed as a whole, the overall spring constant is increased. Therefore, the natural frequency can be increased as compared with the conventional measurement unit as a whole. This is extremely suitable for realizing high-speed weighing. That is, according to the present invention, it is possible to provide a transport weighing device that is more suitable for realizing high-speed weighing than the conventional one.

It is an illustration figure which shows the whole schematic structure of the automatic weight sorter | selector which concerns on one Embodiment of this invention. It is the illustration figure which looked at the measurement conveyor in the same embodiment from the direction different from FIG. It is a block diagram which shows the electrical schematic structure of the control apparatus in the embodiment. It is an illustration figure which shows the aspect of the signal of a certain part in FIG. It is an illustration figure which shows the measurement conveyor in the embodiment with a dynamic model. It is an illustration figure which shows another example of the measurement conveyor in the same embodiment. It is an illustration figure which shows another example of the measurement conveyor in the same embodiment. It is an illustration figure which expands and shows a part of weighing | measuring conveyor in a prior art. It is an illustration figure which shows the measurement conveyor in the prior art with a dynamic model.

  An embodiment of the present invention will be described by taking an automatic weight sorter as an example.

  Referring to FIG. 1, an automatic weight sorter 10 according to the present embodiment measures the weight of an article 100 as an object to be weighed while conveying the article 100 in the direction from the left side to the right side of FIG. The article 100 is selected based on the measurement result, and the weighing conveyor 30 as a transport weighing device, and the feeding conveyor 50 as feeding means provided at the front stage (left side in FIG. 1) of the weighing conveyor 30; And a delivery conveyor 70 as delivery means provided in a subsequent stage of the weighing conveyor 30 (right side in FIG. 1). The article 100 referred to here has, for example, a substantially rectangular parallelepiped shape.

  Referring also to FIG. 2, the weighing conveyor 30 includes a plurality of, for example, a pair of weighing units 30 a and 30 b as weighing units. 2 is a view of the weighing conveyor 30 as viewed from the upstream side in the conveying direction of the article 100. In FIG. 2, the elements other than the weighing conveyor 30 such as the feeding conveyor 50 and the feeding conveyor 70 are shown. The illustration is omitted. The weighing units 30 a and 30 b have the same specifications as each other, and are provided in parallel with the conveyance direction of the article 100. When attention is paid to one of these weighing units 30a and 30b, for example, the left side unit 30a on the left side as viewed from the upstream side (that is, in FIG. 2), the left side unit 30a includes an article support base 32a having a substantially rectangular parallelepiped shape, A load cell 34a of, for example, a robotic type (parallel beam type) is provided as a load sensor for supporting the article support table 32s immediately below the article support table 32a.

  The article support base 32a is formed by, for example, one metal plate formed in a substantially rectangular parallelepiped shape. In particular, the dimension of the article support base 32a in the conveying direction of the article 100, that is, the length dimension, is larger than the dimension of the article 100 in the same direction, and more specifically, about twice to three times the dimension of the article 100. Yes. The dimension of the article support base 32a in the direction transverse to the conveying direction of the article 100, that is, the width dimension is considerably smaller than the length dimension of the article support base 32a. However, the size is necessary and sufficient to form a guide groove 36a described later. Furthermore, the dimension in the vertical direction of the article support base 32a, that is, the height dimension is also smaller than the length dimension of the article support base 32a. On the other hand, for example, from the width dimension of the article support base 32ab. More specifically, the size is such that the rigidity can sufficiently withstand a load F1, which will be described later, including the weight of the article 100. In addition, as shown in FIG. 2, a substantially concave guide groove 36a is formed in the upper part of the article support base 32a. And in this guide groove 36a, the lower part of the chain 90a as an endless traveling body mentioned later is accommodated, that is, the said chain 90a is engaged.

  As described above, the load cell 34a is of the Roval type, and strictly speaking, has the Roval type strain generating body. The robust type load cell 34a is provided such that a pair of beam portions (of the strain body) extend horizontally along the conveyance direction of the article 100 (that is, the length direction of the article support base 32a). In addition, an appropriate movable side support member, for example, a substantially L-shaped movable side support member 38b as viewed from the side as shown in FIG. 1 (b) is provided on the movable part of the load cell 34a (the strain body). , The article support base 32a is firmly coupled to each other. The fixing portion of the load cell 34a is connected to an appropriate fixed side support member, for example, a chassis or the like via a fixed side support member 40a having a substantially L shape when viewed from the side as shown in FIG. The base portion 200 is firmly bonded. That is, the load cell 34a is in a state of supporting the article support base 32a via the movable side support member 38a. And the said load cell 34a exists in the state supported by the base 200 via the stationary-side support member 40a. Furthermore, the load cell 34a has a strain gauge (not shown). Strictly speaking, the strain gauge is attached to the strain generating portion of the strain generating body. The strain gauge forms a bridge circuit, and the bridge circuit outputs an analog load signal Wa1 of, for example, a DC voltage in a mode corresponding to the strain of the strain generating portion of the strain generating body. The analog load signal Wa1 is input to a calculation control device 300, which will be described later, as weight calculation means.

  For example, as shown in FIGS. 1 (a) and 2, the center of the article support base 32a and the center of the load cell 34a are arranged in a direction transversely across the conveying direction of the article 100, that is, in the width direction of the weighing conveyor 30. Are consistent with each other. In particular, as shown in FIG. 2, the guide groove 36a of the article support base 32a is formed so as to be positioned at the center of the article support base 32a. Therefore, the center of the chain 90a engaged in the guide groove 36a also coincides with the centers of the article support base 32a and the load cell 34a. In other words, the centers of the chain 90a, the article support base 32a, and the load cell 34a are located on one vertical plane C1 along the conveyance direction of the article 100. That is, the left unit 30a including the movable support member 38a and the fixed support member 40a is configured so as to be so. Incidentally, as shown in FIG. 1B in particular, the load cell 34a is in a state in which the movable part side is directed to the upstream side and the fixed part side is directed to the downstream side. The side may be directed to the downstream side, and the fixed portion side may be directed to the upstream side.

  The other weighing unit, that is, the right unit 30b also has an article support base 32b and a load cell 34b having the same specifications as those of the left unit 30a. A guide groove 36b is formed in the upper part of the article support base 32b, and a chain 90b having the same specifications as that of the left unit 30a is engaged with the guide groove 36b. Further, the load cell 34b supports the article support base 32b via the movable side support member 38b, and is also supported by the base 200 via the fixed side support member 40b. The load cell 34b has a strain gauge (not shown), and a bridge circuit formed by the strain gauge outputs an analog state load signal Wa2. The analog load signal Wa2 is also input to the arithmetic and control unit 300 described later. In particular, as shown in FIG. 2, the centers of the chain 90b, the article support base 32b, and the load cell 34b are located on one vertical plane C2 along the conveyance direction of the article 100.

  The left and right weighing units 30a and 30b are more detailed so that the respective article support bases 32a and 32b are parallel to each other across the center line CL along the conveying direction of the article 100 as shown in FIG. Are arranged so as to be symmetrical with respect to a vertical plane C0 including the center line CL as shown in FIG. That is, the distances L from the center line CL to the respective centers of the weighing units 30a and 30b (that is, between C0 and C1 and between C0 and C2) are the same. Each chain 90a and 90b that is a component of each of the weighing units 30a and 30b, that is, each chain 90a and 90b that is a component of the weighing conveyor 30 including each of the weighing units 30a and 30b is fed as described below. It is also a component of each of the conveyor 50 and the delivery conveyor 70.

  The feed conveyor 50 is provided in the front stage of the weighing conveyor 30 as described above, and more specifically, each of the article support bases 32a in the front stage of the respective article support bases 32a and 32b of the weighing conveyor 30 (the respective weighing units 30a and 30b). And 32b are provided in series with a pair of article support bases 50a and 50b. The article support bases 50a and 50b of the infeed conveyor 50 are formed by forming a single metal plate in a substantially rectangular parallelepiped shape, similar to the article support bases 32a and 32b of the weighing conveyor 30, and detailed illustration is omitted. However, a substantially concave guide groove similar to that of the article support bases 32a and 32b of the weighing conveyor 30 is formed in the upper part of each. The above-described chains 90a and 90b are engaged with the guide grooves of the article support bases 50a and 50b. The upstream ends of the guide grooves of the article support bases 50a and 50b are, for example, arcuate in order to smooth the running of the chains 90a and 90b that run along the guide grooves as described later. Appropriate processing such as being formed is applied. In addition, a transport conveyor (not shown) is provided in the front stage of the feed conveyor 50, and the article 100 is fed onto the feed conveyor 50 from the transport conveyor.

  The delivery conveyor 70 is provided at the rear stage of the weighing conveyor 30 as described above. Specifically, the delivery conveyor 70 is in series with the article support tables 32a and 32b at the subsequent stage of the article support tables 32a and 32b. A pair of article support bases 70a and 70b are provided. Similarly to the article support bases 32a and 32b of the weighing conveyor 30, each of the article support bases 70a and 70b of the delivery conveyor 70 is formed by a single rectangular metal plate, and detailed illustration is omitted. However, a substantially concave guide groove similar to that of each of the article support bases 32a and 32b of the weighing conveyor 30 is formed in each upper part. The chains 90a and 90b are engaged with the guide grooves of the article support tables 70a and 70b. The downstream end portions of the guide grooves of the article support bases 70a and 70b are formed, for example, in an arc shape in order to smooth the traveling of the chains 90a and 90b that travel along the guide grooves. Appropriate processing is applied. Further, a conveyor of a sorting unit (not shown) is provided at the subsequent stage of the delivery conveyor 70, and the article 100 is sorted on the conveyor of the sorting unit.

  Each chain 90a and 90b is individually wound around two sprockets 92a and 92b corresponding thereto. These sprockets 92a and 92b have the same specifications as each other and are coupled to a rotating shaft of a motor (not shown). When the motor is started, the sprockets 92a and 92b rotate clockwise, for example, in FIG. 1B, and accordingly, the chains 90a and 90b also rotate clockwise. The chains 90 a and 90 b travel along the guide grooves of the conveyors 30, 50 and 70 including the guide grooves 36 a and 36 b of the weighing conveyor 30. Each sprocket 92a and 92b and the motor are provided separately from each conveyor 30, 50 and 70, that is, they are not directly attached to each conveyor 30, 50 and 70. In FIG. 1 (a), the sprockets 92a and 92b are not shown in view of the ease of viewing. Each chain 90a and 90b has a relatively narrow width, although there is a tradeoff with the size and weight of the article 100. Furthermore, as each chain 90a and 90b, a so-called top chain in which an appropriate plate is attached to the surface on the carrier side may be employed.

  According to the automatic weight sorter 10 configured as described above, the article 100 is transported by the above-described transport conveyor, and the article 100 is fed from the transport conveyor onto the feed conveyor 50, and more specifically on the feed conveyor 50. More specifically, each chain 90a and 90b is placed so as to straddle over each chain 90a and 90b, and more specifically, with one side surface of the chain 90a and 90b being orthogonal to the traveling direction of each chain 90a and 90b on the feed conveyor 50. Placed on top. Thus, the article 100 is conveyed on the infeed conveyor 50 along with the traveling chains 90a and 90b. Then, the article 100 is transferred from the feeding conveyor 50 onto the weighing conveyor 30. At this time, the article 100 is transferred from the left and right article support bases 50a and 50b of the infeed conveyor 50 onto the left and right measurement units 30a and 30b (each article support base 32a and 32b) of the weighing conveyor 30 at substantially the same timing. . Then, the article 100 is conveyed on the weighing conveyor 30. Based on the above-described analog load signals Wa1 and Wa2 when the article 100 is being transported on the weighing conveyor 30, strictly based on a digital load signal WD described later, the weight of the article 100 is obtained. That is, weight measurement is performed. The calculation for the weight measurement is performed by the calculation control device 300. Then, the article 100 after the weight measurement is transferred from the weighing conveyor 30 onto the delivery conveyor 70. At this time, the article 100 is transferred from the left and right weighing units 30a and 30b of the weighing conveyor 30 onto the left and right article support bases 70a and 70b of the delivery conveyor 70 at substantially the same timing. Then, after the article 100 is conveyed on the delivery conveyor 70, the article 100 is transferred from the delivery conveyor 70 onto the conveyor of the above-described sorting unit and sorted on the conveyor of the sorting unit.

  Referring to FIG. 3, arithmetic and control unit 300 has two amplifier circuits 302 and 304 to which analog load signals Wa1 and Wa2 are individually input. Each of the amplifier circuits 302 and 304 amplifies the analog load signals Wa1 and Wa2 input thereto by an appropriate gain, and the amplified analog load signals Wa1 ′ and Wa2 ′ are input to the adder circuit 306. . The adder circuit 306 adds the analog load signals Wa <b> 1 ′ and Wa <b> 2 ′ to each other, and the added analog load signal WA is input to the A / D conversion circuit 308. The A / D conversion circuit 308 converts the analog load signal WA input to itself into a digital load signal WD, and the converted digital load signal WD is input to the arithmetic circuit 310. The arithmetic circuit 310 has a CPU (Central Processing Unit) (not shown), and when the article 100 is being conveyed on the weighing conveyor 30 in detail as described above, based on the digital load signal WD input thereto. Based on the digital load signal WD, the weight of the article 100 is obtained, that is, the weight is measured. In order to notify the arithmetic circuit 310 that the article 100 has entered the weighing conveyor 30, for example, an appropriate article detection means such as a photoelectric sensor for detecting the article 100 is provided in front of the weighing conveyor 30. May be. Further, the arithmetic circuit 310 generates a sorting signal for sorting the article 100 in the sorting section based on the weight measurement result. The sorting signal itself and the article in the sorting section using the sorting signal itself are generated. Since the selection procedure of 100 is not directly related to the gist of the present invention, detailed description thereof is omitted here.

  Now, referring again to FIG. 2, for example, when attention is paid to the left unit 30a, when the article 100 is being conveyed on the left unit 30a, a load F1 including the weight of the article 100 is applied to the left unit 30a. . The load F1 is transmitted to the load cell 34a via the chain 90a and the article support base 32a (and the movable side support member 38a) of the left unit 30a. As described above, the chain 90a, the article support base 32a, and the load cell are transmitted. Each center of 34 a is located on one vertical plane C <b> 1 along the conveyance direction of the article 100. This means that the load F1 is transmitted on the vertical plane C1. In other words, it means that the transmission path of the load F1 is on the vertical plane C1. Furthermore, in other words, it means that the transmission path of the load F1 viewed from the upstream side is a vertical line. Therefore, for example, unlike the above-described prior art, moments M1 'and M2' as shown in FIG. 8 do not occur. Therefore, in particular, the article support base 32a can have sufficient rigidity even if it has a relatively simple structure, that is, light weight. Further, since the connecting member 5 as shown in FIG. 8 is not necessary, the left unit 30a as the measuring unit can be further reduced in weight and the rigidity of the left unit 30a can be improved. In the conveyance direction of the article 100, the transmission path of the load F1 to the load cell 34a moves on the vertical plane C1 in accordance with the movement of the article 100. Of course, the same applies to the right unit 30b.

  In addition, when the article 100 is transferred from the feed conveyor 50 onto the weighing conveyor 30, the article 100 is moved from the left and right article support bases 50a and 50b of the feed conveyor 50 to the left and right of the weighing conveyor 30 as described above. Transfer onto the weighing units 30a and 30b (the article support portions 32a and 32b) at substantially the same timing. Therefore, for example, when the distribution of the weight of the article 100 in the width direction of the weighing conveyor 30 is substantially uniform, the applied loads F1 and F2 to the left and right weighing units 30a and 30b including the weight of the article 100 are The weighing units 30a and 30b are applied with substantially the same timing and substantially the same volume ratio. As a result, the analog load signals Wa1 ′ and Wa2 ′ amplified by the amplifier circuits 302 and 304 shown in FIG. 3 corresponding to the weighing units 30a and 30b are respectively (zero (offset) adjustment and span (gain) adjustment). As shown in FIGS. 4A and 4B (assuming that the adjustment is properly performed), the characteristics are substantially the same as each other, and more specifically, the amplitude, frequency, and phase are substantially the same. In addition, when each of the right and left weighing units 30a and 30b is viewed as one spring system, the weighing conveyor 30 as a whole including the weighing units 30a and 30b is shown in FIG. The two spring systems 30a and 30b are connected in parallel. Therefore, for example, if the spring constants of the weighing units 30a and 30b are k1 and k2, the spring constant K of the weighing conveyor 30 as a whole including the weighing units 30a and 30b is K = k1 + k2, which is increased. That is, the spring constant of the entire weighing conveyor 30 can be increased. The analog load signal WA amplified by the adder circuit 306 shown in FIG. 3 has a characteristic as if it was output from one weighing unit as shown in FIG. 4C, that is, such an amplitude. , Frequency and phase. The drive means including the sprockets 92a and 92b and the motors for driving the chains 90a and 90b are provided separately from the conveyors 30, 50 and 70 as described above. Is not included. Accordingly, the weight of the entire weighing conveyor 30 can be reduced by that amount, but this is also the case with the prior art.

  Thus, according to the present embodiment, the weighing conveyor 30 is reduced in weight as in the prior art, but in addition to this, the connecting member 5 as in the prior art is not particularly necessary. The weight can be further reduced and the rigidity can be improved. Further, the spring constant of the weighing conveyor 30 as a whole can be increased. Accordingly, the natural frequency of the weighing conveyor 30 as a whole can be increased as compared with the conventional one, and the weighing conveyor 30 suitable for higher-speed weighing can be provided.

  In addition, this embodiment is one specific example of this invention until it gets tired, and does not limit the scope of the present invention.

  For example, in place of the chains 36a and 36b, endless straps 190a and 190b having a substantially circular cross section as shown in FIG. 6 may be employed. Examples of such endless straps 190a and 190b include rubber straps and metal coils. And when such endless straps 190a and 190b are adopted, according to the shape of the endless straps 190a and 190b, the respective weighing units 30a and 30b (each article support base 32a and It is desirable that the guide grooves 136a and 136b of 32b) have an appropriate shape. Of course, the same applies to the guide grooves of the feed conveyor 50 and the feed conveyor 70.

  Further, at least the weighing conveyor 30 may be conveyed by sliding the article 100 on the weighing conveyor 30 instead of being conveyed by the endless cord band. Specifically, sliding support bases 132a and 132b as shown in FIG. 7 are provided in place of the article support bases 32a and 32b of the left and right weighing units 30a and 30b. These sliding support bases 132a and 132b are similar to the rails disclosed in, for example, Japanese Patent Application Laid-Open No. 2011-242317, and each upper surface is a sliding surface. Further, in order to reduce the friction coefficient of the sliding surface, an appropriate process such as forming the upper part of each sliding support base 132a and 132b in an arc shape and forming a low friction coefficient coating on the surface thereof. Alternatively, the sliding support bases 132a and 132b themselves are made of a material having a low coefficient of friction. According to the configuration shown in FIG. 7, since an endless strap is not required, the weighing conveyor 30 can be further reduced in weight, and the weighing conveyor 30 suitable for higher-speed weighing can be provided.

  Further, in the present embodiment, the weighing conveyor 30 is configured by the pair of weighing units 30a and 30b, but the present invention is not limited to this. That is, the weighing conveyor may be constituted by three or more weighing units.

  And although the load cell 34a and 34b employ | adopted the Robert type, it is not restricted to this. For example, a column type (column type), shear type (shear type), or other type other than the above-mentioned Roval type may be employed.

  In addition, the arithmetic and control unit 300 is not limited to the configuration shown in FIG. For example, in the configuration shown in FIG. 3, the analog load signals Wa1 ′ and Wa2 ′ amplified by the amplifier circuits 302 and 304 are analog-added by the adder circuit 306, and then the analog load signals after addition are added. The WA is converted into the digital load signal WD by the A / D conversion circuit 308. However, the analog load signals Wa1 ′ and Wa2 ′ may be digitally added after being converted into digital load signals. Further, the bridge circuits constituting the load cells 34a and 34b are connected in parallel, one analog load signal is taken out from the bridge circuit connected in parallel, the digital signal is amplified after the one analog signal is amplified. May be converted to

  And as for the article | item 100, if it is not only a substantially rectangular parallelepiped thing but a solid thing, the shape will not be restrict | limited especially.

  Further, in the present embodiment, the automatic weight sorter 10 has been described as an example, but it goes without saying that the present invention can be applied to other than this.

DESCRIPTION OF SYMBOLS 10 Automatic weight sorter 30 Weighing conveyor 30a, 30b Weighing unit 32a, 32b Article support stand 34a, 34b Load cell 50 Feeding conveyor 90a, 90b Chain 100 Article 300 Operation control apparatus

Claims (3)

In a transport and weighing device that measures the weight of an article while transporting the article that is an object to be weighed,
A plurality of article support bases provided in parallel to the article conveyance direction and supporting one article in a conveyance state in cooperation with each other;
A feeding means that is provided in a front stage of the plurality of article support bases in the transport direction and feeds the articles onto the plurality of article support stands so that the articles get on the plurality of article support stands at substantially the same timing; ,
A plurality of articles provided individually corresponding to the plurality of article support tables and supporting the corresponding article support tables and outputting a load signal corresponding to a load transmitted to itself through the corresponding article support table. Load sensors
Weight calculating means for determining the weight of the article based on the plurality of load signals output from the plurality of load sensors;
Comprising
For each combination of the article support table and the load sensor corresponding to the article support table, the load including the weight of the article on the article support table reaches the load sensor via the article support table. The load sensor is provided directly below the article support so as to transmit on a vertical plane along the conveying direction;
Conveyance weighing device characterized by A plurality of substantially endless traveling bodies in the form of strings that are provided individually corresponding to the plurality of article support bases and run on the support parts of the articles in the corresponding article support bases in the same direction and at the same speed. Further,
The article is conveyed by being placed on the plurality of endless traveling bodies,
The transport weighing device according to claim 1. The article is conveyed by sliding on a support portion of the article in each of the plurality of article support platforms.
The transport weighing device according to claim 1.

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