Combination weighing machine

Abstract

To provide a semi-automatic combination weighing machine which can maximally reduce a cost by a simple constitution without needing a wide installation space, can remarkably improve work efficiency, can enhance versatility in response to a variety of weighing objects, and can continuously perform combination weighing.SOLUTION: A combination weighing machine comprises: a weighing machine main body having a plurality of weighing parts, weighing pans which are attachable and detachable to / from the weighing parts, combination weight calculation means, and optimum combination calculation means; and a transportation conveyor for receiving weighing objects on the weighing pans corresponding to an optimum combination, and integrally transporting the weighing objects. The weighing part has a pair of left and right arm shafts which protrude to the outside from one side wall of the weighing machine main body, and relatively rotate, and the weighing pans are vertically arranged at a pair of the left and right arm shafts, composed of a pair of left and right pan pieces which are supported to an upper part of the transportation conveyor, formed into placing pan forms for placing the weighing objects thereon, and have discharge forms of the weighing objects in response to the optimum combination.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a combination weighing machine for weighing objects such as vegetables and food, which has a simple configuration and is capable of efficient weighing. [Background technology]

[0002] Traditionally, fresh food products such as vegetables and other foods have rarely been sold in the market in individual units, such as one stalk, one piece, or one stalk, but have been sold by weight, weighed in combination so that the combined weight of multiple items falls within a specified weight range and packed in bags.

[0003] In other words, in order to package multiple weighed items together into a product form, accurate combination weighing work must be carried out so that the combined weight value of weighed items that are uneven in size, shape, and weight, such as agricultural products, is not below the specified weight value and is the smallest possible combined weight value (hereinafter simply referred to as the optimal combined weight value), while ensuring market credibility and taking economic efficiency into consideration.

[0004] In order to reduce the workload of such combination weighing work performed by baggers, an automatic combination weighing device has been proposed (see, for example, Patent Documents 1 to 3) that fully automates the series of operations from "process of placing the items to be weighed on the weighing pan → process of calculating the optimal combination of the items to be weighed → process of picking up the optimally combined items to be weighed → process of packaging the optimally combined items to be weighed." [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 8-313333 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-166232 [Patent Document 3] Japanese Patent Application Laid-Open No. 2008-292194 Summary of the Invention [Problem to be solved by the invention]

[0006] However, such fully automated combination weighing devices are large and very expensive, and relatively small to medium-sized shipping sources, such as individual farmers or cooperatives, cannot afford to introduce them due to space and financial constraints. In reality, workers weigh and sort each item, checking which items result in the optimal combination weight value.

[0007] Furthermore, when the items to be weighed are agricultural products of different sizes and shapes, such as long vegetables such as burdock or leeks, or granular vegetables such as strawberries or tomatoes, if a conventional automatic combination weighing device is used to perform combination weighing, there is a risk that the cost of the device will be enormous, as it will be necessary to add or redesign a special mechanism to suit the type of item to be weighed.As a result, the types of items that can be weighed in combination weighing are limited, resulting in a lack of versatility.

[0008] The present invention has been made in view of the above circumstances, and provides a semi-automatic combination weighing machine that is portable and easy to install without requiring a large installation space, has a simple configuration that allows for the reduction of device costs as much as possible, is easy to use and can dramatically improve work efficiency, is highly versatile by easily handling a wide variety of objects to be weighed in terms of size, shape, weight, etc., and can perform continuous combination weighing. [Means for solving the problem]

[0009] In order to solve the above-mentioned conventional problems, the present invention provides a combination weighing machine comprising: (1) a weighing machine main body including a plurality of weighing units that weigh objects to generate individual weighed values, weighing pans that are detachable from the weighing units, a combined weight calculation means that performs a combination calculation on the weighed values ​​obtained by the plurality of weighing units to calculate a combined weight value, and an optimal combination calculation means that determines whether the combined weight value is an optimal combined weight value that is the smallest value within a specified weight range and selects a weighing unit from the plurality of weighing units that corresponds to the optimal combination; and a transport conveyor that is installed along one side wall of the weighing machine main body and receives the objects to be weighed on the weighing pans of the weighing units that correspond to the optimal combination and transports them together, a combination weighing machine, characterized in that the weighing section has a pair of left and right arm shafts that protrude outward from one side wall of the weighing machine body above the transport conveyor and in the transport crossing direction of the transport conveyor and rotate relative to one another; the weighing pan consists of a pair of left and right pan pieces that are respectively suspended from the pair of left and right arm shafts and supported above the transport conveyor; the left and right pan pieces are swung toward each other around each arm shaft so that their lower ends face each other and engage, thereby forming a loading pan shape for placing the item to be weighed; and the left and right pan pieces are swung away from each other in an optimal combination so that their lower ends move away from each other, forming a downward opening and forming a discharge shape for dropping and discharging the item to be weighed onto the transport conveyor.

[0010] The combination weighing machine according to the present invention is characterized by the following points (2) to (5). (2) The weighing unit comprises a load cell, a drive shaft disposed on the load cell, and a link mechanism that is connected and fixed to the drive shaft at its base end and that is connected and fixed to the pair of left and right arm shafts at their left and right tip ends that branch out and extend to the left and right sides at their midpoints, and is characterized in that the pair of left and right arm shafts are configured to be freely rotatable relative to each other via the link mechanism when the drive shaft rotates. (3) The link mechanism comprises a drive link connected and fixed to the drive shaft at its base end to rotate, a lower link pivoted at its base end to the tip of the drive link to rotate, one L-shaped link pivoted at its base end to the tip of the lower link and bent in an approximately L shape with its tip facing either the left or right side, an upper link pivoted at its base end to the bent corner of the one L-shaped link to rotate, and another L-shaped link pivoted at its base end to the tip of the upper link and bent in an approximately L shape with its tip facing the other of the left or right side, and the tip of the one L-shaped link and the tip of the other L-shaped link are connected and fixed to the pair of left and right arm shafts, respectively, to convert the rotation of the drive shaft into relative rotation of each arm shaft. (4) A weighing object engaging portion is protruded from one side wall of the weighing machine body facing the weighing pan supported vertically on the arm shaft, and engages with one end of the weighing object placed on the weighing pan. (5) The weighing machine main body has an eccentricity error correction means for adding or subtracting a preset eccentricity correction value according to the type of the object to be weighed to the eccentricity error measurement value generated by the weighing unit as a value smaller or larger than the net weight value when the object to be weighed is placed on the weighing pan of the above-mentioned pan configuration. [Effects of the Invention]

[0011] The combination weighing machine of the present invention is portable and easy to install without requiring a large installation space, has a simple configuration that allows costs to be reduced as much as possible, dramatically improves work efficiency, is highly versatile in that it can handle a wide variety of objects to be weighed in terms of size, shape, weight, etc., and is a semi-automatic combination weighing machine that can perform continuous combination weighing, thereby contributing to society. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is an external perspective view showing the overall configuration of a combination weighing machine according to the present invention. [Figure 2] 1 is an external perspective view showing the configuration of a weighing machine main body according to the present invention. [Figure 3]1 is a schematic front view showing a synchronous operation state of the weighing machine main body and the transport conveyor of the combination weighing machine according to the present invention. [Figure 4] FIG. 2 is a perspective view showing a specific configuration of a measuring unit and a measuring pan according to the present invention. [Figure 5] FIG. 2 is a perspective view showing a specific configuration of a measuring unit and a measuring pan according to the present invention. [Figure 6] FIG. 2 is a perspective view showing a specific configuration of a measuring unit and a measuring pan according to the present invention. [Figure 7] 1 is a schematic explanatory view showing a state in which the weighing pan is used in the loading pan form of the weighing machine main body according to the present invention; FIG. [Figure 8] FIG. 10 is a perspective view showing the configuration of a weighing pan according to a modified example. [Figure 9] 1 is a flowchart showing a basic weighing process of a combination weighing machine according to the present invention. [Figure 10] FIG. 10 is a flowchart showing the synchronous operation of the weighing machine main body and the transport conveyor of the combination weighing machine according to the present invention. [Figure 11] FIG. 10 is an operational flow diagram of a low-speed weighing mode of the combination weighing machine according to the present invention. [Figure 12] FIG. 4 is an operational flow diagram of the combination weighing machine according to the present invention in a high-speed weighing mode. [Figure 13] FIG. 4 is a process flow diagram of the eccentricity error correction means of the combination weighing machine according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] The gist of the present invention is a combination weighing machine comprising: a weighing machine main body including a plurality of weighing units that weigh objects to generate individual weighed values, weighing pans that are detachable from the weighing units, a combination weight calculation means that performs a combination calculation on the weighed values ​​obtained by the plurality of weighing units to calculate a combined weight value, and an optimum combination calculation means that determines whether the combined weight value is an optimum combined weight value that is the smallest value within a specified weight range and selects a weighing unit from the plurality of weighing units that corresponds to the optimum combination; and a transport conveyor that is laid along one side wall of the weighing machine main body and receives and transports the objects to be weighed on the weighing pans of the weighing units that correspond to the optimum combination, The present invention provides a combination weighing machine characterized in that it has a pair of left and right arm shafts that protrude outward from one side wall of the weighing machine body above the transport conveyor and in the transport crossing direction of the transport conveyor and rotate relative to one another, and the weighing pan consists of a pair of left and right pan pieces that are respectively attached vertically to the pair of left and right arm shafts and supported above the transport conveyor, and the left and right pan pieces are configured to swing toward each other around each arm shaft so that their lower ends face each other and engage, thereby forming a loading pan shape on which the item to be weighed is placed, and to swing away from each other in a direction that optimally corresponds to the combination, so that their lower ends move away from each other, forming a downward opening and allowing the item to drop and discharge onto the transport conveyor.

[0014] The weighing unit also includes a load cell, a drive shaft disposed on the load cell, and a link mechanism that is connected and fixed to the drive shaft at its base end and that is connected and fixed to the pair of left and right arm shafts at their left and right tip ends that branch out and extend to the left and right sides in a bifurcated manner at its midpoint, and is characterized in that the pair of left and right arm shafts are configured to be freely rotatable relative to each other via the link mechanism when the drive shaft rotates.

[0015] The link mechanism further comprises: a drive link connected and fixed to the drive shaft at its base end to rotate; a lower link pivotally connected to a tip end of the drive link at its base end to rotate; a first L-shaped link pivotally connected to the tip end of the lower link at its base end and bent in a substantially L shape with its tip end facing either the left or right side; an upper link pivotally connected and rotated at its base end to a bent corner of the first L-shaped link; and a second L-shaped link pivotally connected to the tip end of the upper link at its base end and bent in a substantially L shape with its tip end facing the other of the left or right side, and is characterized in that the tip end of the first L-shaped link and the tip end of the second L-shaped link are connected and fixed to the pair of left and right arm shafts, respectively, so as to convert rotation of the drive shaft into relative rotation of each arm shaft.

[0016] Another feature of the weighing machine is that a weighing object engagement portion is protruded from one side wall of the weighing machine body facing the weighing pan supported vertically on the arm shaft, and engages with one end of the weighing object placed on the weighing pan.

[0017] The weighing machine main body is characterized by having an eccentricity error correction means for adding a preset eccentricity correction value according to the type of the object to the eccentricity error measurement value generated by the weighing unit as a value less than the net weight value when the object to be weighed is placed on the weighing pan of the above-mentioned pan configuration.

[0018] <1. General configuration of combination weighing machine> First, the general configuration of a combination weighing machine A (hereinafter referred to as this weighing machine) according to the present invention will be described. Figure 1 is a perspective view showing the overall configuration of the combination weighing machine, Figure 2 is a front perspective view showing the internal configuration of the weighing machine main body, and Figures 3(a) to 3(c) are schematic front views showing the synchronized operation of the weighing machine main body and the transport conveyor.

[0019] As shown in Figure 1, the weighing machine A is configured by combining a weighing machine main body 1 having a plurality of weighing pans 3 (six in this embodiment) protruding outward at regular intervals in the longitudinal direction from one side wall 10a of a rectangular housing 10, and a transport conveyor 4 laid along one side wall 10a of the weighing machine main body 1 below the plurality of weighing pans 3.

[0020] In Figure 1, reference numeral 6 denotes an indicating mechanism that corresponds to each weighing pan 3 and indicates the combination weighing result, i.e., whether or not the weighing pan 3 corresponds to the optimal combination of items to be weighed, and reference numeral 7 denotes an input section for inputting various settings required for combination weighing, such as the specified weight range.

[0021] The indicator mechanism 6 indicates to the operator the items to be weighed that should be picked up if an optimal combination is available, or notifies the operator that there is no optimal combination if there is no optimal combination. The indicator mechanism 6 is made up of a plurality of display indicators 60 provided on the upper wall 10b of the rectangular housing 10 at positions corresponding to the respective weighing pans 3 and an audio indicator 61 built into the rectangular housing 10.

[0022] The specified weight range, which is arbitrarily input and set into this weighing machine A by the input unit 7, is a specified weight range that the operator sets as appropriate to match the items to be combined and weighed. In other words, the lower limit of the specified weight range is the minimum combined weight value of items that will not cause a loss of market credibility, and the upper limit of the specified weight range is the maximum combined weight value of items that will not cause an economic loss to the operator, etc.

[0023] On the front side (the side where the transport conveyor 4 is located) of the weighing machine main body 1 where multiple weighing pans 3 are arranged in a row, a loading worker is positioned to replenish or increase / decrease the objects to be weighed M on each weighing pan 3. In other words, the loading worker performs the "step of loading the objects to be weighed onto the weighing pans" of the combination weighing work.

[0024] As shown in FIGS. 1 and 2, the weighing pan 3 is composed of a pair of left and right pan pieces 30L and 30R suspended from arm shafts 20L and 20R protruding from one side wall 10a of the rectangular housing 10.

[0025] The left and right dish pieces 30L, 30R rotate in unison relative to each other around the respective arm axes 20L, 20R, and their lower ends engage with each other below the axis positions, thereby freely forming a lower opening 3a in the weighing dish 3.

[0026] In other words, the weighing pan 3 is formed into a V-shaped loading pan form 3A when viewed from the front, which is open at the top and front and back and can accommodate the item to be weighed M, by swinging and displacing the left and right pan pieces 30L, 30R in a direction approaching each other around each arm axis 20L, 20R and abutting and engaging the lower ends 31L, 31R against each other.

[0027] In addition, in accordance with the optimal combination, the weighing pan 3 swings and displaces the left and right pan pieces 30L, 30R in the direction away from each other around each arm axis 20L, 20R, causing the lower ends 31L, 31R to move away from each other, thereby forming a downward opening 3a in the center between the pair of arm axes 20L, 20R, and discharging and dropping the weighed item M onto the transport conveyor 4, resulting in a discharge form 3B.

[0028] Each weighing pan 3 is connected to a plurality of weighing units 2 provided inside the rectangular housing 10 via arm shafts 20L and 20R. Each weighing unit 2 generates a weighing value of the object M placed on the corresponding weighing pan 3 of the loading pan configuration 3A. The number of weighing pans 3 to be used in combination weighing can be set by the operator using the input unit 7.

[0029] In other words, as shown in Figure 2, the weighing machine main body 1 is configured as a hopper unit that opens downward on both sides, allowing for weighing and placement using the weighing section 2 and weighing pan 3, and is configured by arranging multiple such hopper units side by side.

[0030] Details will be described later, but inside the rectangular housing 10 there is provided a control unit 5 which executes a combination weight calculation means S1 which performs a combination calculation of the measurement values ​​obtained by the multiple measurement units 2 to calculate a combined weight value, and an optimal combination calculation means S2 which determines whether the combined weight value is an optimal combined weight value which is the smallest value within a specified weight range, and selects a measurement unit from the multiple measurement units that corresponds to the optimal combination.

[0031] That is, the weighing unit 2, combination weight calculation means S1, and optimum combination calculation means S2 built into the weighing machine main body 1 automatically execute the "step of calculating the optimum combination of weighed objects" of the combination weighing work.

[0032] As shown in Figure 1, the transport conveyor 4 is composed of a pair of transport rollers 43, 43' that are arranged at a fixed interval on the front and rear sides and are driven to rotate, and a transport belt 40 that is suspended endlessly between the pair of transport rollers 43, 43'.As shown in Figures 3(a) to 3(c), the transport conveyor 4 receives the weighed object M that drops from the lower opening 3a of the weighing pan 3 and transports it to the next process position.

[0033] 1, a plurality of partition walls 41 are erected at regular intervals in the conveying direction on the conveyor belt 40, thereby defining a plurality of accumulation / conveyance sections 42 for accumulating and integrating the weighed objects between adjacent partition walls 41. The conveyor 4 is equipped with a position sensor 44 that detects the movement position of each accumulation / conveyance section 42.

[0034] As shown in Figures 3(a) to 3(c), the weighing machine main body 1 changes the weighing pan 3 corresponding to the optimally combined weighing section 2 from the weighed item loading configuration 3A to the weighed item discharge configuration 3B in accordance with the movement of the accumulation and conveying section 42 of the conveying conveyor 4 below, and sequentially discharges and drops the weighed items M.

[0035] In particular, as shown in Figures 3(b) and 3(c), each weighing dish 3 in discharge form 3B can realize discharge transfer by causing the weighed items M corresponding to the optimal combination stored therein to fall approximately vertically (indicated by the dashed arrow in the figure) from directly above the conveying surface of the transport conveyor 4, thereby making it less likely that the weighed items M will be subjected to inadvertent impact when falling, and preventing damage to the weighed items M as much as possible.

[0036] In other words, in discharge mode 3B, the direction in which the weighed item M falls from the lower opening 3a of the weighing pan 3 is perpendicular to the conveying surface of the conveyor 4 as shown in Figures 3(b) and 3(c), so the conveying belt 40 of the conveyor 4 performs a shock absorber function that accurately absorbs and damps the landing impact force of the weighed item M.

[0037] Therefore, when the weighed objects M are transferred from the weighing pan 3 to the transfer conveyor 4, there is no risk that each weighed object M will be subjected to an unexpected physical impact, causing it to move around unexpectedly inside the transfer conveyor 4, or to fall off the transfer conveyor 4, or to suffer bruises or cracks.

[0038] The transport conveyor 4 receives the objects to be weighed M that have been discharged and dropped from the weighing pan 3 of the weighing machine main body 1 in the accumulation and transport section 42, consolidates them, and transports them to the next process. In other words, the weighing machine main body 1 and the transport conveyor 4 are configured to be relatively synchronized and linked by the control section 5. In this way, the "pick-up process of the optimally combined objects to be weighed" of the combination weighing work is stably and automatically performed between the weighing pan 3 of the weighing machine main body 1 and the transport belt 40 of the transport conveyor 4.

[0039] A bagging worker is positioned at the downstream end in the conveying direction of the transport conveyor 4 to pick up and bag the weighed objects M that are conveyed sequentially. That is, the "packaging process of optimally combined weighed objects" of the combination weighing work is carried out by the bagging worker.

[0040] In this way, this weighing machine A is a semi-automated combination weighing machine in which the weighing machine main body 1 and the transport conveyor 4 work together to perform the "process of calculating the optimal combination of items to be weighed → process of picking up the optimally combined items to be weighed" which requires particular precision and skill out of the series of combination weighing tasks performed by an operator: "process of placing items to be weighed on the weighing pan → process of calculating the optimal combination of items to be weighed → process of picking up the optimally combined items to be weighed → process of packaging the optimally combined items to be weighed."

[0041] <2. Configuration of the weighing machine body> Next, the specific configuration of the weighing machine main body will be described with reference to the drawings. Figures 4 to 6 are perspective views showing the specific configuration of the weighing unit and weighing pan, Figures 7(a) and 7(b) are schematic plan and side views showing the weighing pan in use in the loading pan mode, and Figures 8(a) and 8(b) are perspective views showing the configuration of a weighing pan according to a modified example.

[0042] The weighing machine main body 1 is composed of a hollow rectangular housing 10, a plurality of weighing units 2 arranged along the longitudinal direction of the rectangular housing 10, a plurality of weighing pans 3 that protrude from one side wall 10a of the rectangular housing 10 via arm axes 20L and 20R and are arranged side by side in the longitudinal direction of each weighing unit 2, and a control unit 5 that executes a combination weight calculation means S1 and an optimal combination calculation means S2.

[0043] The rectangular housing 10 is configured as a horizontally placed hollow rectangular box, with a rectangular parallelepiped outer frame that forms the outer shell of the weighing machine main body 1 and six side walls that cover the outer periphery of the outer frame. As shown in Fig. 1, one side wall 10a on the front side of the rectangular housing 10 has a plurality of rectangular windows 100a (six in this embodiment) cut out at regular intervals from the bottom edge in the longitudinal direction, into which a support wall 24 (described later) can be fitted.

[0044] As shown in Fig. 2, the inner bottom of the rectangular housing 10 is provided with a plurality of intermediate frames 11 that divide the interior space of the rectangular housing 10 horizontally at regular intervals in the longitudinal direction. These intermediate frames 11 divide the interior space of the rectangular housing 10 into a plurality of spaces (six in this embodiment), and the weighing units 2 are neatly arranged in each intermediate frame 11, as shown in Figs. 2 and 4.

[0045] The weighing unit 2 is configured to have a pair of left and right arm shafts 20L, 20R that protrude outward from one side wall 10a of the rectangular housing 10 above the conveying conveyor 4 and in the conveying direction crossing the conveying conveyor 4, and rotate relative to each other, and weighs the items to be weighed to generate individual measurement values.

[0046] Specifically, as shown in Figures 4 to 6, the weighing unit 2 includes a load cell 21, a drive shaft 22 arranged on the load cell 21, and a link mechanism 23 that is connected and fixed to the drive shaft 22 at its base end and that extends bifurcated to the left and right at its midpoint and that connects and fixes the pair of left and right arm shafts 20L, 20R at their left and right tip ends, respectively, and is configured so that the pair of left and right arm shafts 20L, 20R can rotate freely relative to each other via the drive shaft 22 via the link mechanism 23.

[0047] The load cells 21 are each a generally rod-shaped so-called beam-type load cell, which is mounted and fixed on the intermediate frame 11 and connected to the control unit 5, which will be described later. As shown in FIGS. 5 and 6, the load cells 21 are provided in the form of a cantilevered tip beam, with their base ends fixed to the approximate center of the intermediate frame 11 via a spacer of a certain thickness and their tips made approximately flush with one side wall 10a of the rectangular housing 10.

[0048] In addition, reference numeral 21a in FIG. 4 denotes a bolt screw that is screwed into the upper surface of the base end of the load cell 21 and fixed to the lower intermediate frame 11, and this facilitates removal and makes assembly and maintenance work easier.

[0049] A support wall 24 that integrally supports the drive shaft 22, link mechanism 23, and arm shafts 20L, 20R is erected on the tip end 21b of the load cell 21. The support wall 24 is a rectangular plate with a predetermined thickness when viewed from the front, and is loosely fitted into the rectangular window 100a of the rectangular housing 10 in a floating state, so as to be flush with one side wall 10a and form a wall of the rectangular housing 10.

[0050] On the outer front side of the support wall 24, i.e., on one side wall 10a of the weighing machine main body 1 facing the weighing pan 3 supported vertically on the arm shafts 20L and 20R, there is provided a protruding weighing object engaging portion 25 that engages with one end of a long weighing object placed on the weighing pan 3, as shown in Figures 2, 7(a) and 7(b).

[0051] 7(a) and 7(b), the weighing object engaging portion 25 is configured with an L-shaped bracket 250 protruding from the approximate center of the front of the support wall 24 between the pair of left and right arm shafts 20L, 20R when viewed from the front. This allows the end of a long vegetable placed on the weighing pan 3 to be positioned and engaged with the lower side of the L-shaped side, stabilizing the position of the weighing object M during weighing.

[0052] That is, when the object to be weighed M is a long vegetable, the position of the object to be weighed M on the weighing pan 3 is as shown in Figures 7(a) and 7(b), with the front of the object to be weighed M extending beyond the front opening of the weighing pan 3, the middle part abutting against the front lower edge of the weighing pan 3, and the rear end of the object to be weighed abutting and engaging with the object to be weighed engaging portion 25, resulting in a stable position in which the object to be weighed M is engaged with the weighing pan 3 at two fulcrums.

[0053] The weighed object engaging portion 25 is not particularly limited as long as it can engage with the end of the weighed object M placed on it, and may be, for example, a protrusion with a sharp tip that can be inserted and engaged with the end of the weighed object M.

[0054] The support wall 24 also includes a bracket 240 that protrudes from the lower back surface to support the drive shaft 22, and bearing holes 241L, 241R for the arm shafts 20L, 20R that are formed on the upper left and right sides, respectively, and penetrate forward and backward.

[0055] In other words, as shown in Figures 4 to 6, the weighing section 2 is configured by mounting a support wall body 24, on which a drive shaft 22, a pair of left and right arm shafts 20L, 20R and a link mechanism 23 therebetween are respectively mounted in series, on a load cell 21 with a weighing function.

[0056] As shown in Figures 5 and 6, the drive shaft 22 is a rotating shaft of a drive mechanism 220 attached to the center of the lower back surface of the support wall 24 via a bracket 240, and protrudes from the back surface of the support wall 24 to rotate vertically.

[0057] The drive mechanism 220 is not particularly limited as long as it can control the direction and amount of rotation of the drive shaft 22 using the control unit 5, and may be, for example, a servo motor or a rotary solenoid. By using such a servo motor or rotary solenoid in the drive mechanism 220, the durability of the device can be improved while keeping component costs down.

[0058] As shown in Figures 5 and 6, the link mechanism 23 is a roughly T-shaped five-bar link mechanism in which five links 230-234 are connected by four joints 230a-233a to connect between the lower drive shaft 22 and the pair of upper left and right arm shafts 20L, 20R, and each link 230-234 is configured to bend and swing freely around each joint 230a-233a as the drive shaft 22 rotates.

[0059] Specifically, as shown in Figures 5 and 6, the link mechanism 23 is composed of: a drive link 230 whose base end is connected and fixed to the drive shaft 22 of the drive mechanism 220 and which rotates; a lower link 231 whose base end is pivotally connected to the tip of the drive link via a first joint 230a; a one-side L-shaped link 232 whose base end is pivotally connected to the tip of the lower link via a second joint 231a and which is bent in a substantially L-shape with its tip facing either the left or right side; an upper link 233 whose base end is pivotally connected to the L-shaped corner of the one-side L-shaped link 232 via a third joint 232a; and a other-side L-shaped link 234 whose base end is pivotally connected to the tip of the upper link via a fourth joint 233a and which is bent in a substantially L-shape with its tip facing the other of the left and right sides.

[0060] The tip ends of the pair of left and right L-shaped links 232, 234 are connected and fixed to the base ends 20aL, 20aR of the corresponding pair of left and right arm shafts 20L, 20R, respectively, and are configured to convert the rotation of the drive shaft 22 into relative rotation of each arm shaft 20L, 20R.

[0061] 4 to 6, the pair of left and right arm shafts 20L, 20R protrude outward from the inside to the outside of the rectangular housing 10 through left and right bearing holes 241L, 241R in the support wall 24, and the respective outward protrusions 20bL, 20bR support the left and right pan pieces 30L, 30R hanging down to form the weighing pan 3. The length of the outward protrusions 20bL, 20bR is approximately the same as the width of the transport conveyor 4 below.

[0062] As shown in Figures 4 to 6, the left and right dish pieces 30L, 30R are rectangular plates 300R, 300L, respectively, and are removably fixed at their upper longitudinal edges to the outward protrusions 20bL, 20bR of each arm shaft 20L, 20R via bolts or the like.

[0063] The widths of the left and right dish pieces 30L, 30R are formed so that the sum of their widths is longer than the distance between the arm shafts 20L, 20R. In other words, the dish pieces 30L, 30R are formed with a width such that when the arm shafts 20L, 20R rotate relative to each other, the lower ends 31L, 31R hanging down from the arm shafts 20L, 20R face each other at a position below the arm shafts 20L, 20R and approximately in the center between the arm shafts 20L, 20R.

[0064] The lower end portions 31L, 31R of the left and right dish pieces 30L, 30R are formed into female-male engaging portions 310L, 310R that engage when they face each other, as shown in Figures 4 to 6. The female-male engaging portions 310L, 310R are formed by cutting out the lower end edges of the left and right dish pieces 30L, 30R in a corrugated pattern that is out of phase with each other, and then intersecting with each other to form a female-male engaging portion.

[0065] The weighing dish 3 of this configuration is a V-shaped, elongated dish when viewed from the front, with the top and front and rear sides open, in a loading dish form 3A in which the lower ends 31L, 31R of the left and right dish pieces 30L, 30R are rotated and displaced close to each other around a pair of arm axes 20L, 20R to engage each other.

[0066] As shown in Figures 8(a) and 8(b), the left and right dish pieces 30L, 30R may be formed as symmetrical, roughly C-shaped pieces 320L, 320R in cross section with front and rear side walls 321L, 322L, 321R, 322R erected at their respective front and rear end edges, making the weighing dish 3 of the loading dish form 3A a mortar dish with closed front and rear openings, or they may be formed as bent pieces bent at a predetermined angle at their midpoints, making the weighing dish 3 of the loading dish form 3A a bottomed dish.

[0067] In other words, by replacing the left and right pan pieces 30L and 30R, the weighing pan 3 can select the loading pan form 3A according to the size and shape of the object to be weighed. For example, when weighing long vegetables such as green onions and burdock, a long and narrow pan with a front and back as shown in Figures 7(a) and 7(b) is used, and when weighing granular vegetables such as strawberries and cherry tomatoes, a mortar-shaped pan or a bottomed pan as shown in Figures 8(a) and 8(b) is used.

[0068] The weighing pan 3 configured as described above changes between the loading pan configuration 3A and the discharge configuration 3B as follows: When the weighing pan 3 outside the rectangular housing 10 is in the loading pan configuration 3A, the link mechanism 23 inside the rectangular housing 10 is in a substantially T-shaped configuration 23A, as shown in FIG.

[0069] That is, inside the rectangular housing 10, the link mechanism 23 has a drive link 230 with its tip pointing in the 12 o'clock direction centered on the drive shaft 22, a lower link 231, the short side of the L-shaped link 232 on one side, and an upper link 233, which are arranged in a straight line above and below, and the long side of the L-shaped link 232 on one side and the L-shaped link 234 on the other side are arranged extending in the left and right directions, forming an approximately T-shaped shape 23A.

[0070] Opposite to this link mechanism 23 of approximately T-shape 23A, the weighing pan 3 on the outside of the rectangular housing 10 has a loading pan shape 3A in which the left and right pan pieces 30L, 30R are inclined around the arm axes 20L, 20R and the lower ends 31L, 31R are engaged facing each other, allowing the loading operator to place and receive the item to be weighed M.

[0071] On the other hand, when the weighing pan 3 outside the rectangular housing 10 is in the discharge configuration 3B, the link mechanism 23 inside the rectangular housing 10 is in a substantially Y-shape 23B as shown in FIG.

[0072] That is, inside the rectangular housing 10, the link mechanism 23 has a drive link 230 with its tip pointing in the 9 o'clock direction centered on the drive shaft 22, a lower link 231 pulled downward and left by the drive link 230, the short side of the L-shaped link 232 on one side, and the upper link 233 each formed in a linear shape inclined to the left, and the long side of the L-shaped link 232 on one side and the other L-shaped link 234 formed in a downward inclined shape pulled down approximately at the center between the left and right arm shafts 20L and 20R, forming an approximately Y-shaped shape 23B.

[0073] Opposite to this link mechanism 23 of approximately Y-shape 23b, the weighing pan 3 on the outside of the rectangular housing 10 is in a loading pan form 3A in which the left and right pan pieces 30L, 30R are positioned approximately vertically around the arm axes 20L, 20R, and the lower ends 31L, 31R are separated from each other to form a downward opening 3a, making it possible to drop and supply the weighed item M corresponding to the optimal combination onto the transport conveyor 4.

[0074] In other words, as shown in FIGS. 5 and 6, as the link mechanism 23 is displaced from the approximate T-shape 23A to the approximate Y-shape 23B, the weighing pan 3 is displaced from the loading pan form 3A to the discharge form 3B.

[0075] That is, in the link mechanism 23 inside the rectangular housing 10, as the drive shaft 22 rotates, the drive link 230 swings and changes position from the 12 o'clock position to the 9 o'clock position, and the lower link 231 connected to the tip of each link swings downward as if pulled downward, changing from a straight position to a downwardly inclined position, and the tips of both L-shaped links 232, 234 in the downwardly inclined position rotate the arm shafts 20L, 20R downward relative to each other.

[0076] In other words, the rotational force of the drive shaft 22 is divided and converted by the link mechanism 23 into a downward relative rotational force of the arm shafts 20L and 20R, and is ultimately transmitted as a separating swing force of a pair of left and right pan pieces 30L and 30R connected to each arm shaft 20L and 20R outside the rectangular housing 10, causing the weighing pan 3 to change from the loading pan form 3A to the discharge form 3B in which a downward opening 3a is formed, and the weighed item M stored inside falls and discharges onto the transport conveyor 4.

[0077] When the weighing tray 3 is displaced from the discharge configuration 3B to the loading tray configuration 3A, the operation is reversed from the above-described displacement, that is, the link mechanism 23 is displaced from the approximate Y-shape 23B to the approximate T-shape 23A.

[0078] In this way, the weighing machine main body 1 can convert the rotation of one drive shaft 22 into relative and synchronized rotation of a pair of left and right arm shafts 20L, 20R using the link mechanism 23 provided on the load cell 21, thereby enabling the weighing pan 3 to be reliably displaced between the discharge configuration 3B and the loading pan configuration 3A.

[0079] Furthermore, since the driving source is a single driving mechanism 220, it is easy to control the shape displacement of the weighing pan 3, and since the weight of the components has been reduced to the minimum possible extent, load deterioration is unlikely to occur even if each component such as the link mechanism 23 is integrally connected to the load cell 21.

[0080] <3. Basic weighing process flow of combination weighing machine> Next, we will explain the basic processing flow of combination weighing in this weighing machine A. Figure 9 is a basic weighing processing flow diagram for combination weighing of the weighing machine. This flow is the main routine required for weighing processing, and progresses in the order of combination weight calculation processing S1 → optimal combination calculation processing S2.

[0081] First, when an operator places an object M to be weighed on each weighing pan 3 of the loading pan configuration 3A, each corresponding weighing unit 2 generates a weight value for the object M. For example, if six weighing units are used, six corresponding weight values ​​are generated. Each weighing unit 2 continues to generate weight values ​​at all times, regardless of whether an object M is placed on it or not.

[0082] (1) Combination weight calculation process S1 Next, the control unit 5 executes a combination weight calculation process S1 as a combination weight calculation means built into the weighing machine main body A1. In the combination weight calculation process S1, the respective measurement values ​​generated in the weighing process S1 are acquired, and a combination calculation of the respective measurement values ​​is performed to calculate a combined weight value. That is, in the combination weight calculation process S1, a combination calculation is performed on the measurement values ​​of each weighing unit 2, and multiple combined weight values ​​are calculated as individual integrated weights corresponding to the combination patterns.

[0083] (2) Optimal combination calculation process S2 Next, the control unit 5, which will be described later, executes an optimum combination calculation process S2 as optimum combination calculation means built into the weighing machine main body A1. In the optimum combination calculation process S2, it is determined whether the combined weight value is an optimum combined weight value that is the smallest value within a specified weight range, and if an optimum combined weight value is found, the weighing unit 2 corresponding to the optimum combination is selected from the multiple weighing units 2.

[0084] That is, in the optimum combination calculation process S2, the actual combination weight value is discriminated between those that are within the specified weight range and those that are outside the specified weight range, and if it is within the specified weight range, the optimum combination weight value that is "greater than or equal to the lower limit of the specified weight range and is the smallest value within the specified weight range" is selected.

[0085] For example, when the operator sets the desired specified weight range to 300g to 350g, if the combined weight values ​​of the weighed objects calculated by the combined weight calculation process S1 are 320g and 330g, which are within the specified weight range, then in the optimal combination calculation process S2, the smallest value of these, 320g, becomes the optimal combined weight value.

[0086] That is, when the weighing object is placed on at least two of the weighing units 2 selected for use via the input unit 7, and the combined weight value falls within the specified weight range, optimal combination data is generated to calculate the optimal combined weight and select the weighing unit 2 corresponding to the optimal combination.

[0087] If there is a combination within the specified weight range, the combination where the combined weight value ≧ specified weight value = minimum weight value is determined to be the optimal combination, and optimal combination data is generated for selecting the weighing unit 2 according to this optimal combination.

[0088] In particular, if there are multiple combinations within the specified weight range, only one combination where the combined weight value ≥ specified weight value = minimum weight is set as the optimal combined weight value. In other words, if the combined weight is "lower limit of the specified weight range ≤ combined weight value = minimum weight value ≤ upper limit of the specified weight range," optimal combination data is generated.

[0089] On the other hand, when the weighing objects are placed on all weighing units 2 selected for use via the input unit 7 and the combined weight value deviates from the specified weight range, the optimal combination calculation process S2 generates error data indicating that there is no optimal combination.

[0090] In other words, if the combined weight is "combined weight value < lower limit of the specified weight range (combined weight value is less than the lower limit of the specified weight range)" or "combined weight value > upper limit of the specified weight range (combined weight value exceeds the upper limit of the specified weight range)", error data will be generated.

[0091] <4. Synchronous operation flow of weighing machine body and transport conveyor> Next, the synchronous drive of the weighing machine main body and the transport conveyor of the combination weighing machine will be explained. Figure 10 is a flow diagram of the synchronous operation of the weighing machine main body and the transport conveyor. The operation control of the weighing machine main body 1 and the transport conveyor 4 in this weighing machine A, the basic weighing process flow mentioned above, and various weighing processes to be described later are mainly performed by the control unit 5.

[0092] The control unit 5 is built into a predetermined position in the rectangular housing 10 of the weighing machine main body 1, and is electrically connected in the weighing machine main body 1 to the load cell 21 for generating the weighing value of the weighing unit 2 and the drive mechanism 220 as the drive shaft 22, the display indication units 60 and audio indication units 61 of the indication mechanism 6, the input unit 7, and in the transport conveyor 4 to the transport rollers 43 and position sensor 44.

[0093] The control unit 5 is composed of a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and flash memory. The ROM stores programs for executing the combination weight calculation process S1 and optimal combination calculation process S2, which are processed by the CPU, as well as various operating modes and programs for executing the synchronized operation of the weighing machine main body 1 and the transport conveyor 4, and the RAM functions as a temporary storage area when the CPU executes the programs.

[0094] The specified weight range and the transfer pitch of the transfer conveyor 4 are set for the control unit 5 via the input unit 7 .

[0095] The weight of the object M placed on each weighing pan 3 of the weighing machine main body 1 is transmitted as measurement value data generated by the load cell 21 of the weighing unit 2 to the control unit 5. In addition, the transport conveyor 4 transmits position data of the accumulation and transport unit 42 detected by the position sensor 44 to the control unit 5.

[0096] The control unit 5, which receives the weighing value data, executes the combination weight calculation process S1 and the optimum combination calculation process S2, which are basic weighing process flows, and transmits the optimum combination data or error data of each weighing pan 3 (weighing unit 2) to the indication mechanism 6 of the weighing machine main body 1. The indication mechanism 6, which receives various data, lights up or sounds a sound according to the type of data to notify the loading operator of the combination result.

[0097] That is, the indication mechanism 6 that has received the optimal combination data operates to notify the operator of the corresponding weighing pans 3. Specifically, among the multiple indication mechanisms 6 that have received the optimal combination data, only the display indication unit 60 of the indication mechanism 6 that corresponds to the weighing pan 3 on which the object to be weighed M that corresponds to the optimal combination is turned on to notify the operator of the optimal combination.

[0098] On the other hand, the indicator mechanism 6 that has received the error data operates to issue an error notification to inform the operator that there is no combination. This error notification may be made by an audible message from the audio indicator 61 saying "There is no combination," or by all of the display indicators 60 lighting up or flashing at the same time.

[0099] Furthermore, the control unit 5 transmits rotation command data to the drive mechanism 220 of the weighing unit 2 corresponding to the weighing pan 3 on which the objects to be weighed M corresponding to the optimal combination are placed, prompting the drive mechanism 220 to operate at the timing when the accumulation and conveyance unit 42 passes. Upon receiving the rotation command data, the drive mechanism 220 rotationally drives the drive shaft 22 to oscillate and displace the link mechanism 23 from the approximate T-shape to the approximate Y-shape, thereby displacing each weighing pan 3 corresponding to the optimal combination from the loading pan configuration 3A to the discharge configuration 3B at the timing when the accumulation and conveyance unit 42 is positioned below it.

[0100] That is, in accordance with the movement timing of the accumulation and conveyance section 42 of the transport conveyor 4, which is constantly driven for transport, the control section 5 sets only the weighing tray 3 on which the weighed objects M corresponding to the optimal combination are placed to the discharge form 3B, and executes a "pickup process of the weighed objects of the optimal combination" in which the weighing tray 3 in the discharge form 3B effectively drops and accumulates the weighed objects M that make up the optimal combination onto the same accumulation and conveyance section 42. The weighing tray 3 in the discharge form 3B shifts to the loading tray form 3A immediately after discharging the weighed objects M so that new weighed objects M can be placed on it.

[0101] The transport conveyor 4 may be equipped with a standby means for preventing weighed objects to be discharged to the packaging section at the end point from being discharged before the completion of each packaging run. The standby means may be implemented by a pre-programmed control unit 5 that interlocks the weighing machine main body 1 and the transport conveyor 4 and performs an intermittent operation of alternately stopping and operating so that the amount of movement of the accumulation and transport section 42 of the transport conveyor 4 corresponds sequentially to the position of each weighing section 2. In other words, the weighing machine A is equipped with a synchronization means that adjusts the speed and / or temporary stop time according to the position of the transport conveyor.

[0102] <5. Low-speed weighing mode and high-speed weighing mode> Next, we will explain the low-speed weighing mode and high-speed weighing mode as operating conditions of the combination weighing machine A. Figures 11 and 12 are operation flow diagrams for the low-speed weighing mode and high-speed weighing mode, respectively. The combination weighing machine A is configured so that the operator can arbitrarily select between the two modes, low-speed weighing mode and high-speed weighing mode, via the input unit 7 as operating conditions for the synchronously interlocked weighing machine main body 1 and transport conveyor 4.

[0103] (a) Low-speed weighing mode The low-speed weighing mode is an effective mode for workers who are unfamiliar with placing the objects M to be weighed on the weighing pan 3 and packaging the optimally combined objects M to be weighed that are sequentially transported to the end of the transport conveyor 4.

[0104] In the low-speed weighing mode, when weighing objects M are placed on all weighing pans 3 (weighing sections 2) in the loading pan configuration 3A, the weighing pans 3 corresponding to the optimal combination are sequentially changed to discharge configuration 3B from the upstream side to the downstream side by the link mechanism 23 depending on the movement position of the accumulation and conveying section 42 of the transport conveyor 4 that moves, and the weighing objects M of the optimal combination are accumulated and conveyed to the most downstream side by the transport conveyor 4, and after all of the weighing pans 3 in discharge configuration 3B have changed to the loading pan configuration 3A, the combination weighing is reset and a new combination weighing and conveying is performed.

[0105] Specifically, when optimal combination data is generated through the combination weight calculation process S1 and optimal combination calculation process S2 as part of the basic weighing process flow described above, the weighing pan 3 that receives this data switches to discharge form 3B and sequentially drops and discharges the weighed items M onto the accumulation and transport section 42 of the transport conveyor 4, and the weighing values ​​constantly generated in the weighing section 2 fluctuate, resetting the weighing process.

[0106] In addition, if error data that does not have an optimal combination is generated, the indication mechanism 6 will issue an error notification, and if the worker increases or decreases the weighing object M that has been placed in response to this, the weighing value constantly generated by the weighing unit 2 will similarly fluctuate and the weighing process will be reset.

[0107] In other words, the procedure is as follows: Place the objects to be weighed M on all weighing pans 3 → Determine whether there is an optimal combination using the combination weight calculation process S1 and the optimal combination calculation process S2 → The weighing value fluctuates due to the discharge or increase or decrease of the objects to be weighed → Reset the weighing.This mode can be said to be tailored to the pace of each individual loading operation by a loading operator who is unfamiliar with dividing the objects to be weighed, etc.

[0108] (b) High-speed weighing mode The high-speed weighing mode is effective for skilled loading and bagging workers, and is a mode that significantly increases the speed of combination weighing work per unit time.

[0109] The high-speed weighing mode has the same basic operation as the low-speed weighing mode, but is a continuous weighing calculation mode in which, even if there is a weighing pan 3 that corresponds to the optimal combination and has become discharge form 3B, the optimal combination of the remaining weighing pans 3 with loading pan form 3A is automatically calculated, and if an optimal combination is found, the optimal combination is discharged and transported.

[0110] Specifically, when optimal combination data is generated through the combination weight calculation process S1 and optimal combination calculation process S2 as part of the basic weighing process flow described above, the weighing pans 3 that have received this data assume the discharge configuration 3B and drop and discharge the objects to be weighed M one after another onto the accumulation and transport section 42 of the transport conveyor 4. Some of the weighing pans 3 that have assumed the discharge configuration 3B are displaced back to their original loading pan configuration 3A, but separately, the remaining weighing pans 3 in loading pan configuration 3A perform the basic weighing process one after another.

[0111] In other words, even if all weighing dishes 3 to be used are not in the loading dish form 3A, the weighing dishes 3 that are in the loading dish form 3A at that time are constantly combined and weighed, and then dropped onto the transport conveyor 4 in an integrated manner.

[0112] This high-speed weighing mode dramatically improves work efficiency because it refills the weighing pan 3 that has been emptied after returning from discharge form 3B to loading pan form 3A with the weighed item M, while simultaneously calculating a new combined weighing between the weighing pan 3 of other loading pan form 3A that already has the weighed item M loaded on it.

[0113] <6. Eccentricity error correction means> Next, we will explain the eccentricity error correction means of the weighing machine main body 1. Fig. 13 is a process flow diagram of the eccentricity error correction means. The weighing machine main body 1 has an eccentricity error correction means S3 that adds an eccentricity correction value that is set in advance in accordance with the type of the object to be weighed M to the eccentricity error measurement value generated by the weighing unit 2 as a value less than the net weight value when the object to be weighed M is placed on the weighing pan 3 in the loading pan configuration 3A.

[0114] As described above, the weighing machine main body 1 is configured such that the weighing pan 3 protrudes from the weighing section 2 inside the rectangular housing 10 toward one side wall 10a and is supported cantilevered upward. As a result, the distance between the load cell 21 that detects the weight of the item M and the weighing pan 3 on which the item M is placed becomes longer, and offset errors may occur depending on the location where the item M is placed on the weighing pan 3 and the shape and size of the item M.

[0115] For example, if the items to be weighed M are concentrated near the front of the weighing pan 3 in the loading pan configuration 3A, the biased load of the items to be weighed M will be applied to the tips of the arm axes 20L and 20R, and there is a risk that the net load of the items to be weighed M will not be applied to the load cell 21 located at the bottom of the base end.

[0116] The eccentricity error in the weighing machine main body 1 has a specific eccentricity error value depending on the type of weighed object M. In other words, the weighing value by the weighing unit 2 that includes the eccentricity error tends to be generated as an eccentricity error weighing value obtained by subtracting an eccentricity error value of about 12g to 8g for long vegetables such as chives, leeks, and burdock, and about 7g to 3g for short vegetables such as carrots, from the net weight value.

[0117] That is, this means sets in advance in the control unit 5 via the input unit 7 an eccentricity error value obtained based on the tendency of the type of the weighed object M as an eccentricity correction value, and adds the eccentricity correction value to the eccentricity error measurement value generated by the weighing unit 2 to execute the eccentricity error correction process S3.

[0118] This allows the eccentricity error value generated by the weighing unit 2 as an eccentricity error to be corrected to a weighing value that approximates the net weight of the object to be weighed M placed on each weighing pan 3, and then provided to the combination weight calculation process S1 and the optimal combination calculation process S2.

[0119] If the offset correction value corresponding to the type of weighed object M is stored as a preset setting in the control unit 5, it can be called up and set as appropriate for each weighed object M for each combination of weighing targets. Furthermore, this process S3 is preferably performed before the basic weighing process flow, in particular before the optimal combination calculation process S2.

[0120] <7. Other weighing and processing methods> Next, we will explain other weighing processing means of the combination weighing machine A. The combination weighing machine A is equipped with the following various means (1) to (3) that improve the accuracy and workability of combination weighing. The following various means are selected and set by the operator via the input unit 7.

[0121] (1) Suboptimal combination method This means is realized by the control unit 5 receiving error data from the optimum combination calculation process and executing the optimum combination process when the operator sets the use of the quasi-optimum value.

[0122] The suboptimal value is a value greater than the upper limit of the specified weight range, and is intended to be the highest combined weight value of the objects M to be weighed that is considered economical for the worker, etc. In other words, the suboptimal value range is a range of values ​​greater than the upper limit of the specified weight range and less than or equal to the suboptimal value. By setting this suboptimal value, an error will not be immediately reported even if the specified weight range is exceeded, giving the worker the freedom to choose which object M to pick up that falls within the suboptimal value.

[0123] In the suboptimal combination process, if the combined weight value of the objects to be weighed M deviates from the upper limit of the specified weight range and is a value below the suboptimal value, suboptimal combination data is generated to select each weighing unit corresponding to the suboptimal combination. If there are multiple suboptimal values, the smallest weight value in the suboptimal value range is set as the suboptimal value. In other words, if the combined weight value is "upper limit of the specified weight range < combined weight value = smallest weight value ≦ suboptimal value," suboptimal combination data is generated.

[0124] On the other hand, if the combined weight value of the objects to be weighed M is greater than the suboptimal value, error data is generated to notify that there is no suboptimal combination. In other words, if the combined weight is "combined weight value > suboptimal value (combined weight value exceeds the suboptimal value)", error data is generated.

[0125] The suboptimal combination data generated by the suboptimal combination process and various types of error data are transmitted to the instruction mechanism 6, which then performs an announcement operation according to the type of each data.

[0126] That is, the instruction mechanism 6 that receives the suboptimal combination data operates to notify the operator of each weighing pan 3 that corresponds to the combination. On the other hand, the instruction mechanism 6 that receives error data from the suboptimal combination process operates to notify the operator that there is no optimal combination. This gives the operator the freedom to choose how to pick up the objects M to be weighed that correspond to the suboptimal combination, improving work efficiency.

[0127] (2) Measurement value selection means Next, we will explain the measurement value selection means of this weighing machine A. That is, this means is a means for preventing noise measurement values ​​that have been inadvertently generated due to external factors from participating in the combination weight calculation process S1. In other words, the measurement value selection process, which is executed by setting noise measurement values ​​that are not to be used as the weight value of the object to be weighed M in the control unit 5 by the input unit 7, functions as the measurement value selection means.

[0128] In the measurement value selection process, if the measurement value generated by the weighing unit 2 is "measurement value ≦ noise measurement value (measurement value is less than or equal to the noise measurement value)", noise processing is performed to prevent the measurement value from participating in the combination weight calculation process S1, and if the measurement value is "measurement value > noise measurement value (measurement value exceeds the noise measurement value)", participation processing is performed to allow the measurement value to participate in the combination weight calculation process S1.

[0129] That is, in the weight value selection process, noise processing is performed for weight values ​​below the noise weight value so that noise weight values ​​of the weighing pan 3 on which no weighing object M is placed are not included in the combined weight calculation process S1, and participation processing is performed for weight values ​​above that value to include them in the combined weight calculation process S1. Note that the noise weight value is often between 4g and 7g depending on the external environment, and the operator inputs this 4g to 7g into the control unit 5 using the input unit 7 as a noise weight value and executes the weight value selection process.

[0130] That is, among the multiple weighing units 2, any weighing unit 2 that generates a weighing value equal to or less than the noise weighing value will not participate in the subsequent combination weighing calculation of the combination weight calculation process S1, and only weighing units 2 that generate a weighing value greater than the noise weighing value can participate in the combination weighing calculation of the combination weight calculation process S1. This prevents the weighing machine main body 1 from erroneously recognizing that an object is placed on the weighing pan 3 when no object is actually placed thereon, thereby improving the accuracy of the combination weighing.

[0131] (3) Auto-calibration method Next, we will explain the auto-calibration means of this weighing machine A. This means automatically corrects the weight value of foreign matter other than the object to be weighed, such as soil that has inadvertently accumulated on the weighing pan 3 during repeated weighing, to 0 g so that it is not added to the combined weight calculation process S1, and executes the combined weight calculation process S1 using the net weight value of the object to be weighed M.

[0132] In the auto-calibration process, if a weighing value that matches a value below the calibration correction value is detected consecutively a predetermined number of times among the weighing values ​​generated by the multiple weighing units 2, a zero process is performed to correct the weighing value on the weighing pan 3 corresponding to the detection result to 0 g.

[0133] That is, the auto-calibration process is carried out by the control unit 5, which serves as an auto-calibration means and to which a calibration correction value is set by the input unit 7 so that the weight of the object other than the object to be weighed is not added to the weight of the object to be weighed.

[0134] The auto-calibration process executes zero processing only when the weighed value is equal to or less than the calibration correction value and is detected consecutively a set number of times or more. For example, if the calibration correction value is set to 2 g and the number of detections is set to 3, the auto-calibration process executes zero processing, correcting the weighed value of the weighing unit 2 from 1 g to 0 g, only when 1 g is detected three times in succession as the weighed value by the weighing unit 2. This prevents the weight of accumulated foreign matter from being added as a weighed value to the combination weight calculation process S1, making it possible to perform optimal combination weighing using the net weighed value of the weighed object M, and to produce bagged products that meet the specified weight.

[0135] The auto-calibration process is preferably executed after the aforementioned measurement value selection process. The auto-calibration process may also be executed in synchronization with the reset of the notification from the indicating mechanism 6.

[0136] As has been explained above, according to the present invention, a semi-automatic combination weighing machine can be realized which is portable and easy to install without requiring a large installation space, which has a simple configuration that allows costs to be reduced as much as possible, which can dramatically improve work efficiency, which is highly versatile in that it can handle a wide variety of objects to be weighed in terms of size, shape, weight, etc., and which can perform continuous combination weighing, thereby contributing to society. [Explanation of symbols]

[0137] A Combination weighing machine 1 Weighing machine body 10 Rectangular housing 2 Measuring part 3 Weighing pan 4. Transport conveyor

Claims

1. a weighing machine body including: a plurality of weighing units that weigh objects to generate individual weighed values; weighing pans that are detachable from the weighing units; a combined weight calculation means that performs a combination calculation on the weighed values ​​obtained by the plurality of weighing units to calculate a combined weight value; and an optimal combination calculation means that determines whether the combined weight value is an optimal combined weight value that is the smallest value within a specified weight range and selects a weighing unit from the plurality of weighing units that corresponds to the optimal combination; and a transport conveyor that is installed along one side wall of the weighing machine body, and that receives the objects to be weighed on the weighing pans of the weighing units that correspond to the optimal combination and transports them together, The measuring unit is a pair of left and right arm shafts that protrude outward from one side wall of the weighing machine body above the transport conveyor and in the transport crossing direction of the transport conveyor and rotate relative to one another; a load cell; a drive shaft disposed on the load cell; and a link mechanism that is connected and fixed to the drive shaft at a base end and that extends bifurcated to the left and right sides at a midpoint and that is connected and fixed to the pair of left and right arm shafts at left and right tip ends, respectively, and that is configured so that the pair of left and right arm shafts can rotate relative to one another via the link mechanism by rotation of the drive shaft, The weighing pan is A combination weighing machine characterized in that it comprises a pair of left and right pan pieces that are respectively attached vertically to a pair of left and right arm shafts and supported above the transport conveyor, and the left and right pan pieces are configured to swing toward each other around each arm shaft so that their lower ends face each other and engage, thereby forming a loading pan shape on which the item to be weighed is placed, and to swing away from each other in a direction corresponding to the optimal combination so that their lower ends move apart, thereby forming a downward opening and allowing the item to drop and be discharged onto the transport conveyor.

2. 2. The combination weighing machine according to claim 1, wherein the link mechanism comprises: a drive link connected and fixed at a base end to the drive shaft to rotate; a lower link pivotally connected at a base end to a tip end of the drive link to rotate; a first L-shaped link pivotally connected at a base end to the tip end of the lower link and bent in a substantially L-shape with its tip end facing either the left or right side; an upper link pivotally connected at a base end to a bent corner of the first L-shaped link to rotate; and a second L-shaped link pivotally connected at a base end to the tip end of the upper link and bent in a substantially L-shape with its tip end facing the other of the left or right side, and the tip end of the first L-shaped link and the tip end of the second L-shaped link are connected and fixed to the pair of left and right arm shafts, respectively, so that rotation of the drive shaft is converted into relative rotation of each arm shaft.

3. A combination weighing machine according to claim 1 or 2, characterized in that a weighing object engaging portion is protruded from one side wall of the weighing machine body facing the weighing pan supported vertically on a pair of arm shafts, and engages with one end of the weighing object placed on the weighing pan.

4. The combination weighing machine according to any one of claims 1 to 3, characterized in that the weighing machine main body has an eccentricity error correction means for adding an eccentricity correction value that is set in advance in accordance with the type of the object to an eccentricity error measurement value generated by the weighing unit as a value less than a net weight value when an object to be weighed is placed on the weighing pan of the above-mentioned loading pan configuration.

Images