Electronic scale and method for adjusting electronic scale

Abstract

To provide an electric scale and a method for adjusting an electric scale which can suppress a manufacturing cost and also can increase the workability of adjusting the lower limit position of a free end of a load cell.SOLUTION: An electric scale 1 includes: a body case 3; a measuring unit 7 located in the upper part of the body case 3; and a store clerk-side operation unit 50 for displaying a measured value of the measuring unit. The measuring unit 7 includes: a load cell 72 having one end as a fixed end and another end as a free end 72B, a measuring board 70 being placed on the free end; a base part 74 to which the one end of the load cell 72 is fixed. A base part 74 is provided with a screw hole 74B for adjusting the sinking amount of the free end 72B at the position of a screw 74C. In a ceiling 36 of the body case 3 where the base part 74 is set, there is an opening part 36A for pushing the screw 74C into the screw hole 74B.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an electronic balance and a method for adjusting an electronic balance. [Background technology]

[0002] A known example of a conventional electronic scale is that described in Patent Document 1. The electronic scale described in Patent Document 1 includes a bar scale body, a load cell that is installed on the bar scale body and has a free end (movable end) and a fixed end (support end), and an overload prevention stopper that is attached directly or indirectly to the free end of the load cell. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 1-23630 Summary of the Invention [Problem to be solved by the invention]

[0004] In electronic scales, when a load of approximately 200% of the rated load is applied to a load cell, the load cell deflects, causing damage to the strain gauge of the load cell. Therefore, in electronic scales, the distance between the free end of the load cell and the abutment member is set so that the free end of the load cell abuts the abutment member when the load cell deflects a predetermined amount. For example, this distance is less than 1 mm for an electronic scale with a weighing capacity of 3 kg. Therefore, it is necessary to precisely machine (manufacture) each part of the main body base on which the load cell and the abutment member are installed, and to precisely assemble the load cell to the main body base to prevent manufacturing errors. This results in a problem of high manufacturing costs.

[0005] To solve this problem, as disclosed in the electronic scale of Patent Document 1, a large distance can be created between the free end of the load cell and the abutment member, a gap gauge can be inserted there, and the minute gap can be adjusted using a screw-type overload prevention stopper. In this way, the lowest position at which the free end of the load cell sinks can be precisely adjusted by operating the overload prevention stopper. However, if the height of the weighing unit that houses the load cell is reduced to, for example, about 3 cm, the load cell will have a reduced height and a wide width, and the base member that supports it will also need to be equipped with a reinforcing member that surrounds the load cell. This creates the problem of not being able to secure enough space between the free end of the load cell and the abutment member to insert a gap gauge from the side and adjust it.

[0006] One aspect of the present invention aims to provide an electronic scale and an adjustment method for an electronic scale that can reduce manufacturing costs and improve workability when adjusting the lower limit position of the free end of a load cell. [Means for solving the problem]

[0007] An electronic scale according to one aspect of the present invention comprises a main body case, a weighing unit provided on the top of the main body case, and a display unit that displays the weighing value of the weighing unit. The weighing unit comprises a load cell having one end fixed and the other free end on which a weighing pan is placed, and a base unit to which one end of the load cell is fixed. The base unit has a screw hole for adjusting the amount of sinking of the free end by the position of the screw, and the ceiling of the main body case on which the base unit is installed has an opening for screwing a screw into the screw hole.

[0008] In an electronic scale according to one aspect of the present invention, the base has a screw hole for adjusting the amount of sinking of the free end of the load cell by adjusting the position of the screw, and the ceiling of the main body case on which the base is mounted has an opening for threading the screw into the screw hole. Therefore, in the electronic scale, the lowest sinking position of the load cell can be adjusted by inserting a tool such as a wrench into the opening in the ceiling of the main body case and adjusting the screw. Therefore, even if the processing precision of the base is low, the lowest sinking position of the load cell can be easily adjusted. As a result, the electronic scale can reduce manufacturing costs and improve the ease of adjusting the lowest sinking position of the free end of the load cell.

[0009] In one embodiment, the main body case may be provided with an opening / closing portion that opens and closes the opening. In this configuration, the opening / closing portion can restrict access to the screw through the opening.

[0010] A method for adjusting an electronic scale according to one aspect of the present invention is a method for adjusting the amount of sinking of the free end of the above-mentioned electronic scale, in which a weight equivalent to the amount of sinking when the free end sinks to its limit is loaded onto the weighing pan, the weighing value at that time is displayed on the display unit, and in that state a screw is screwed into the screw hole and fixed at the position where the weighing value on the display unit begins to become unstable.

[0011] In a method for adjusting an electronic scale according to one aspect of the present invention, the lower limit position of the free end of the load cell can be adjusted while viewing the weight value on the display. Therefore, the lower limit position can be adjusted accurately while viewing the display without using a feeler gauge. Therefore, even if an electronic scale is already on the market, the lower limit position can be easily adjusted when replacing the load cell, etc. [Effects of the Invention]

[0012] According to one aspect of the present invention, it is possible to reduce manufacturing costs and improve the workability in adjusting the lower limit position of the free end of the load cell. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a perspective view of an electronic balance according to an embodiment. [Figure 2] FIG. 2 is a perspective view of the electronic balance of FIG. 1 with the door of the main body case open. [Figure 3] FIG. 3 is a perspective view of the measuring section as seen from below. [Figure 4] FIG. 4 is a cross-sectional view of the measuring section. [Figure 5] FIG. 5 is a perspective view showing the inside of the main body case of the electronic balance. [Figure 6] FIG. 6 is a perspective view showing a cross-sectional configuration of the electronic balance. DETAILED DESCRIPTION OF THE INVENTION

[0014] A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. In the description of the drawings, identical elements are designated by the same reference numerals, and duplicate explanations will be omitted. For ease of explanation, this specification will refer to the side on which the clerk operation unit 50 is located as the "front," the side on which the main body case 3 is located as the "rear," the side to the left as viewed from the front as the "left," and the side to the right as viewed from the front as the "right," when viewing the electronic scale 1 with the clerk operation unit 50 located on one side of the main body case 3 as shown in FIG. 1 , but this does not limit the configuration of the present invention.

[0015] The electronic scale 1 has the function of measuring the weight of a product and issuing a print label LC to be affixed to the weighed product. As shown in Figures 1 and 2, the electronic scale 1 includes a main body case 3, a main body operation unit 5, a measuring unit 7, a printer unit 9, and a control unit 10.

[0016] The main body case 3 is provided with a weighing unit 7, a printer unit 9, and a control unit 10. The main body case 3 has a generally rectangular parallelepiped shape. The dimension of the main body case 3 in the front-to-rear direction (length dimension) is greater than the dimension of the main body case 3 in the left-to-right direction (width dimension).

[0017] An opening / closing door 32 is provided on the front of the main body case 3. The opening / closing door 32 opens and closes an opening 34 of the main body case 3. The opening / closing door 32 extends in the left-right direction on the front of the main body case 3, and is provided so as to be able to swing around an axis provided at the lower end of the opening 34. The opening / closing door 32 is provided so as to be able to open and close relative to the opening 34 by rotating around the axis at the lower end. When the opening / closing door 32 is in an open state, the printer unit 9 is exposed.

[0018] 1 and 2, the main body operation unit 5 is provided in the main body case 3. The main body operation unit 5 has a store clerk operation unit (display unit) 50 arranged on the front surface of the main body case 3, and a customer operation unit (not shown) arranged on the rear surface of the main body case 3.

[0019] The clerk operation unit 50 is, for example, a touch panel. Information necessary for operating the electronic scale 1 is displayed on the clerk operation unit 50 under the control of the control unit 10. The clerk operation unit 50 may be configured to include a touch panel and fixed keys. If fixed keys are included, keys necessary for a fee scale, such as a "unit price" key, a "fixed amount" key, a "tare" key, a "print" key, and a "call" key, may be provided, and these may be appropriately arranged together with the numeric keys.

[0020] When the user selects a product to be weighed from the product list displayed on the clerk operation unit 50, or enters the call number of the product to be weighed and then presses the "call" key, the registered information of the selected or called product to be weighed is read from the product master and displayed. When the user then places the product on the weighing platform 70, the weight, price, product name, etc. are displayed on the liquid crystal displays of the clerk operation unit 50 and the customer operation unit. In addition to the weight and price, various advertising messages about the product are displayed on the liquid crystal display of the customer operation unit.

[0021] As shown in Fig. 2, the clerk-side operation unit 50 is attached to the main body case 3 via a hinge mechanism 11. The hinge mechanism 11 connects the main body case 3 and the clerk-side operation unit 50. The hinge mechanism 11 enables the clerk-side operation unit 50 to swing between a first position P1 (see Fig. 1) facing the front surface of the main body case 3 and a second position P2 (see Fig. 2) where the clerk-side operation unit 50 is retracted from the front surface of the main body case 3 and opens the opening / closing door 32.

[0022] As shown in FIGS. 1 and 2, the weighing unit 7 is disposed at the top of the main body case 3. The weighing unit 7 mainly includes a weighing platform (weighing pan) 70, a load cell 72 (see FIG. 4), a base 74 (see FIGS. 3 and 4), a signal processing circuit (not shown), and a transmission module. The load cell 72 is disposed at the bottom of the weighing platform 70 and converts mechanical strain generated when an object to be weighed is placed on the weighing platform 70 into an electrical signal and outputs the electrical signal. The signal processing circuit amplifies the electrical signal output from the load cell 72 and converts it into a digital signal. The transmission module transmits the digital signal to the control unit 10 in the main body case 3 wirelessly or via a wired connection.

[0023] As shown in Fig. 4, the load cell 72 has a fixed end 72A, a free end 72B, and a strain-generating part sandwiched between them. The fixed end 72A is one end of the load cell 72 in the extension direction (longitudinal direction). The free end 72B is the other end of the load cell 72 in the extension direction (the other end). The fixed end 72A is fixed to a base part 74. The weighbridge 70 is placed on the free end 72B via a support member 76. The load cell 72 and the support member 76 are connected by a bolt B.

[0024] The base portion 74 is provided with the load cell 72, a signal processing circuit, a transmission module, etc. As shown in Figures 3 and 4, a screw hole 74B is provided in a bottom portion 74A of the base portion 74. The screw hole 74B is located below the free end 72B of the load cell 72. The screw hole 74B penetrates the bottom portion 74A in the thickness direction.

[0025] A screw 74C is threaded into the screw hole 74B. The screw 74C is provided in the screw hole 74B so that it can be adjusted to move forward or backward. That is, by rotating the screw 74C, the screw 74C can be moved closer to or farther away from the load cell 72. When the screw 74C is screwed in, the screw 74C moves closer to the load cell 72. The screw 74C is provided with an engagement portion (not shown) that engages with, for example, a hex wrench. The screw 74C is used to adjust the amount of sinking of the free end 72B of the load cell 72. The lower limit position of the free end 72B of the load cell 72 is the position where the free end 72B abuts against the tip of the screw 74C. The distance between the free end 72B of the load cell 72 and the screw 74C corresponds to the amount of sinking of the free end 72B of the load cell 72. When a load of a predetermined amount or more is applied to the weighbridge 70, the free end 72B of the load cell 72 comes into contact with the screw 74C.

[0026] As shown in FIG. 6, an opening 36A for threading a screw 74C into a screw hole 74B is provided in the ceiling 36 of the main body case 3 on which the base portion 74 is installed. The ceiling 36 is located below the base portion 74. The opening 36A is located below the screw hole 74B of the base portion 74 in the vertical direction of the main body case 3. As shown in FIGS. 5 and 6, a partition plate 38 is provided below the ceiling 36. The partition plate 38 forms a storage space in which a cassette 90 (see FIG. 2) is stored. The partition plate 38 has an opening 38A. The opening 38A is located below the opening 36A of the ceiling 36 in the vertical direction of the main body case 3. In other words, the opening 38A is located below the screw hole 74B of the base portion 74 in the vertical direction of the main body case 3.

[0027] The screw hole 74B of the base portion 74, the opening 36A of the ceiling 36, and the opening 38A of the partition plate 38 are positioned on the same straight line in the vertical direction of the electronic balance 1. When adjusting the screw 74C of the base portion 74, a hex wrench is inserted through the openings 38A and 36A and operated via the openings 38A and 36A.

[0028] 2, the printer unit 9 is housed in the main body case 3. The printer unit 9 is housed behind the opening and closing door 32 of the main body case 3. The printer unit 9 includes a cassette 90, a printing unit 91, a cutter unit 92, and a temporary attachment unit 93.

[0029] The cassette 90 detachably supports a label roll (a printable belt), not shown. The cassette 90 is formed with a roll support section (not shown) that can support the label roll in a cantilevered state, and the label roll is attached to the roll support section. Here, the label roll will be described. A label roll is formed by winding a belt-shaped linerless label around a paper tube. A linerless label (hereinafter simply referred to as a "label") has an adhesive applied to the back side of the paper base material, a heat-sensitive agent that changes color when heated to the front side (printing surface) and a silicone resin as a release agent on top of that. The label roll is wound around the cardboard tube with the back side (adhesive surface) of the label facing inward. Also, instead of linerless labels, a label roll with a liner-attached label wound around it may be used.

[0030] The cassette 90, printing unit 91, cutter unit 92, and temporary adhesive unit 93 in the printer unit 9 form a label feed path. The feed path is formed vertically from bottom to top. The terms "upstream" and "downstream" used in the following description refer to "upstream" and "downstream" in the feed direction in which labels are fed from the label roll in the feed path. The printer unit 9 is arranged with the cassette 90, printing unit 91, cutter unit 92, and temporary adhesive unit 93 in that order from upstream along the feed path.

[0031] The printing unit 91 has a print head 91A and a platen roller 91B. The print head 91A is provided on the back surface of the opening and closing door 32 and prints product information on the surface of the label. The print head 91A is a thermal print head. The print head 91A is controlled by the control unit 10, which will be described in detail later. When the opening and closing door 32 is closed, the print head 91A is positioned so that it comes into contact with the platen roller 91B.

[0032] The platen roller 91B is positioned to face the position of the print head 91A when the access door 32 is closed. The platen roller 91B presses against the back side of the label, forcing the front side of the label against the print head 91A. The platen roller 91B is a drive roller that is driven by a drive motor (not shown). The circumferential surface of the platen roller 91B is formed unevenly to reduce the contact area with the label surface.

[0033] The cutter unit 92 cuts off the label fed from the print unit 91 into printed labels LC (see FIG. 1) of a predetermined length. That is, the cutter unit 92 cuts out the portion of the label that has been printed by the print head 91A as the printed label LC. The cutter unit 92 is attached to the upper part of the opening 34 of the main body case 3.

[0034] The temporary attachment unit 93 holds the label from both sides when the printed label LC is cut off from the label by the cutter unit 92. The temporary attachment unit 93 holds the printed label LC cut off by the cutter unit 92 from both sides, and also retracts the rear end (upstream end in the payout path) of the printed label LC to a position where it does not come into contact with the front end (downstream end in the payout path) of the label being fed out subsequently, and bonds the leading end of the subsequent label to the adhesive surface of the preceding printed label LC. The temporary attachment unit 93 overlaps the printed labels LC, which have been cut one by one, onto the rear end of the preceding printed label LC, forming a continuous label sheet.

[0035] As shown in FIG. 1, the control unit 10 is a part that controls various operations in the electronic scale 1, and the CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory) are interconnected via bus lines such as an address bus and a data bus. The control unit 10 executes various control processes in the electronic scale 1. For example, the control unit 10 can be configured as software in which a program stored in the ROM is loaded onto the RAM and executed by the CPU. The control unit 10 may also be configured as hardware such as electronic circuits.

[0036] The control unit 10, for example, receives a digital signal transmitted from the weighing unit 7, calculates the price by multiplying the mass obtained from the received signal by a preset unit price per unit mass, and displays the calculated price on the liquid crystal displays of the clerk operation unit 50 and the customer operation unit.

[0037] Next, a method for adjusting the amount of sunkness of the free end 72B of the load cell 72 in the electronic scale 1 will be described. To adjust the amount of sunkness of the free end 72B, the clerk-side operation unit 50 is moved from the first position P1 shown in FIG. 1 to the second position P2 shown in FIG. 2. Next, the opening and closing door 32 of the main body case 3 is opened. This exposes the cassette 90. Next, the cassette 90 is pulled forward and removed from the main body case 3.

[0038] Furthermore, a predetermined operation (an operation for displaying the adjustment mode screen) is performed on the clerk-side operation unit 50, and a screen for adjusting the amount of sinking of the free end 72B of the load cell 72 is displayed. The screen displays the weight value of the weight to be loaded on the weighbridge 70. Next, a weight equivalent to the amount of sinking when the free end 72B sinks to its limit is loaded onto the weighbridge 70. For example, if the rated load of the load cell 72 is 6 kg, a 10 kg weight is loaded onto the weighbridge 70. Once the weight is loaded onto the weighbridge 70, the weight value of the weight is displayed on the clerk-side operation unit 50. The weight value may be a high-resolution digital value corresponding to the mass of the weighed weight, or a digital value obtained by performing a predetermined rounding process on the original signal.

[0039] Next, with the weight loaded on the weighing platform 70, a hex wrench is inserted through the openings 38A and 36A and engaged with the screw 74C. Then, the hex wrench is rotated to thread the screw 74C into the screw hole 74B. This causes the screw 74C to advance toward the load cell 72 (approach the load cell 72). When the screw 74C comes into contact with the free end 72B of the load cell 72, the weighing value displayed on the clerk-side operation unit 50 begins to fluctuate (the weighing value fluctuates). When the weighing value begins to fluctuate, the rotation of the hex wrench is stopped. In other words, the screw 74C is fixed at the position where the weighing value begins to fluctuate. In this way, the amount of sunk of the free end 72B of the load cell 72 can be adjusted.

[0040] As described above, in the electronic scale 1 according to this embodiment, the base 74 of the weighing unit 7 has a screw hole 74B for adjusting the sinking amount of the free end 72B of the load cell 72 by adjusting the position of the screw 74C. The ceiling 36 of the main body case 3 on which the base 74 is installed has an opening 36A for threading the screw 74C into the screw hole 74B. Therefore, in the electronic scale 1, the lowest sinking position of the load cell 72 can be adjusted by inserting a tool such as a hex wrench into the opening 36A in the ceiling 36 of the main body case 3 and adjusting the screw 74C. Therefore, in the electronic scale 1, even if the processing precision of the base 74 is low, the lowest sinking position of the load cell 72 can be easily adjusted. As a result, the electronic scale 1 can reduce manufacturing costs and improve the ease of adjusting the lowest position of the free end 72B of the load cell 72.

[0041] In the method for adjusting the sinking amount of the free end 72B of the load cell 72 of the electronic scale 1 according to this embodiment, the lower limit position of the free end 72B of the load cell 72 can be adjusted while observing the weighing value on the store clerk operation unit 50. Therefore, the lower limit position can be adjusted with high precision while observing the store clerk operation unit 50, without using a feeler gauge. Therefore, even if the electronic scale 1 is already on the market, the lower limit position can be easily adjusted when the load cell 72 or the like is replaced.

[0042] Although the embodiments of the present invention have been described above, the present invention is not necessarily limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present invention.

[0043] In the above embodiment, an example has been described in which the partition plate 38 is provided in the main body case 3, and the screw 74C is adjusted via the opening 38A of the partition plate 38 and the opening 36A of the ceiling 36. However, the partition plate 38 does not have to be provided in the main body case 3. In the electronic scale 1, it is sufficient that at least the opening 36A for threading the screw 74C into the screw hole 74B is provided in the ceiling 36 of the main body case 3 on which the base part 74 is installed.

[0044] In addition to the above embodiment, the main body case 3 may be provided with an opening / closing part that opens and closes the opening 38A of the partition plate 38. The opening / closing part may be a seal, a cover, or the like. The cover may slide to open and close the opening 38A, or may swing to open and close the opening 38A. In this configuration, the opening / closing part can restrict access to the screw 74C through the opening 38A. In a configuration in which the main body case 3 does not have a partition plate 38, an opening / closing part that opens and closes the opening 36A may be provided. [Explanation of symbols]

[0045] 1...electronic scale, 3...main body case, 7...measuring section, 36A...opening, 36...ceiling, 50...store clerk operation section (display section), 70...measuring platform (measuring pan), 72...load cell, 72B...free end, 74...base section, 74B...screw hole, 74C...screw.

Claims

1. The main body case and a measuring unit provided on an upper portion of the main body case; a display unit that displays the measurement value of the measuring unit, The weighing unit includes a load cell having one end fixed and the other free end on which a weighing pan is placed; a base portion to which the one end of the load cell is fixed, The base portion is provided with a screw hole for adjusting the amount of sinking of the free end by the position of the screw, The electronic scale has an opening in the ceiling of the main body case on which the base is installed, through which the screw is screwed into the screw hole.

2. The electronic balance according to claim 1 , wherein the main body case is provided with an opening / closing part that opens and closes the opening.

3. 3. A method for adjusting the amount of sinking of the free end of the electronic balance according to claim 1, comprising: A method for adjusting an electronic scale, comprising: loading a weight on the weighing pan that corresponds to the amount of sinking when the free end sinks to its limit; displaying the weighing value at that time on the display; screwing the screw into the screw hole in that state; and fixing the screw at the position where the weighing value on the display begins to become unstable.

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