Balance

Abstract

To provide a balance capable of preventing an excessive load from being applied to a measuring part without detaching a weighing pan.SOLUTION: The balance (10) includes a measurement part (11) for converting an applied force into an electric signal, a storage part (12) for storing an object to be weighed, a rod-like support part (13) provided between a lower part of the storage part (12) and the measurement part (11), and a regulation member (14) provided around the support part (13) for regulating inclination of the support part (13). When an unbalanced load is applied to the storage part (corresponding to the weighing dish) at the time of cleaning, maintenance, or the like, the support part is inclined, and the inclination is regulated by the regulation member. Accordingly, the excessive load can be prevented from being applied to the measurement unit without detaching the accommodation unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a scale. The term "scale" refers to "a measuring instrument used to measure the mass of an object by utilizing the gravity acting on the object" (JIS (Japanese Industrial Standards) B7611-1, also defined in the OIML (International Organization for Legal Metrology) Recommendation R76-1). [Background technology]

[0002] One type of scale uses a load cell in its measuring section. A load cell is a device that converts an applied force into an electrical signal and includes a strain body made of an elastic material and a strain sensor that converts the magnitude of the strain in the strain body into an electrical signal. Strain sensors include strain gauges, piezoelectric elements, magnetostrictive sensors, and capacitance sensors, with strain gauges being the most commonly used. The strain body has a fixed part that is fixed to another member and a movable part that is movable relative to the member. In a scale that uses a load cell, a weighing pan is placed on a movable part, and gravity acting on an object to be weighed placed on the weighing pan is applied to the movable part. The magnitude of the strain generated in the strain body is converted into an electrical signal by a strain sensor, and the magnitude of the electrical signal is converted into the mass of the object to be weighed (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-036588 Summary of the Invention [Problem to be solved by the invention]

[0004] When an excessive load is applied to the weighing pan during cleaning or maintenance of a scale, the strain body of the load cell may plastically deform beyond its elastic range. Therefore, typical scales are equipped with a mechanism to protect the strain body when such an overload is applied. However, when an excessively unbalanced load is applied to the weighing pan, a typical overload prevention mechanism may not be sufficient to protect the strain body. Therefore, the scale described in Patent Document 1 has a configuration in which a support member is fixed to the movable part and the weighing pan is placed on the support member without being fixed. This allows the weighing pan to detach from the support member when an unbalanced load exceeding a certain magnitude is applied to the weighing pan, thereby preventing the overload from being applied to the strain body. However, if the weighing pan detaches from the support member, the weighing pan must be re-placed on the support member, which is a tedious process.

[0005] Up to this point, we have used an example in which a load cell is used as the measuring unit, but even when using a measuring unit other than a load cell, such as an electromagnetic type, it is desirable to avoid such excessive unbalanced loads and the weighing pan coming off.

[0006] The problem to be solved by the present invention is to provide a scale that can prevent the weighing pan from coming off and can prevent an overload from being applied to the measuring section. [Means for solving the problem]

[0007] The balance according to the present invention, which has been made to solve the above problems, comprises: a measuring unit that converts the applied force into an electrical signal; a storage section for storing the object to be weighed; a rod-shaped support portion provided between a lower portion of the accommodation portion and the measurement portion; a restricting member provided around the support portion to restrict the inclination of the support portion; Equipped with. [Effects of the Invention]

[0008] In the scale according to the present invention, if an unbalanced load is applied to the storage section (including the weighing pan) during cleaning or maintenance, the support section will tilt, and this tilt is regulated by the regulating member. This prevents the storage section (weighing pan) from coming off and prevents an overload from being applied to the measuring section. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a partial vertical cross-sectional view showing an embodiment of a scale according to the present invention. [Figure 2] FIG. 10 is a partially enlarged vertical cross-sectional view showing a state in which the bottom surface of the accommodating portion abuts against a protrusion due to an excessive load in the vertical direction. [Figure 3] 10 is a partially enlarged vertical cross-sectional view showing a state in which a part of a side surface of a support portion comes into contact with a restricting member due to an excessive load in a direction other than the vertical direction. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of a scale according to the present invention will be described with reference to FIGS.

[0011] (1) Configuration of the scale of this embodiment As shown in FIG. 1, the scale 10 of this embodiment includes a load cell (corresponding to the measuring section) 11, a housing section (weighing pan) 12, a support section 13, a regulating member 14, a housing 15, and the like.

[0012] The load cell 11 is housed in a housing 15. The load cell 11 has a known configuration, including a strain body 111 made of an elastic material and multiple strain gauges (not shown). The strain body 111 has a fixed part 1111, a movable part 1112 located on the side of the fixed part 1111, and a beam part 1113 connecting the fixed part 1111 and the movable part 1112. The fixed part 1111 is fixed to the housing 15 by a first fixture 112. The multiple strain gauges are all attached to the beam part 1113. The movable part 1112 can move up and down. When the movable part 1112 moves up and down, the strain of the beam part 1113 changes, and the magnitude of the electrical signal output by each strain gauge changes depending on the magnitude of the strain. Therefore, the magnitude of the electrical signal output by each strain gauge corresponds to the amount of vertical movement of the movable part 1112.

[0013] The storage unit 12 is provided outside the housing 15 and above the top plate 151 of the housing 15. The storage unit 12 has a bottom 121 and a side edge 122 extending upward from the periphery of the bottom 121. In the scale 10 of this embodiment, the storage unit 12 is provided with the side edge 122 shaped to correspond to the outer shape of the side of a standard-sized container B so as to be suitable for weighing a liquid sample LS in the container B. Specifically, the inner diameter of the side edge 122 is set to 38 mm to accommodate a container B with a diameter of 34.2 mm.

[0014] The support part 13 is a rod-shaped member that is provided on the bottom part 121 of the storage part 12 and extends downward. In this embodiment, a cylindrical member (15 mm in diameter and 35 mm in length in this embodiment) is used for the support part 13, but support parts 13 of other shapes and sizes may be used. The support part 13 is inserted into a hole 152 provided in an upper plate 151 of the housing 15, and a portion near the lower end is located inside the housing 15. In this embodiment, the storage part 12 and the support part 13 are integrally molded. Alternatively, the storage part 12 and the support part 13 may be fabricated as separate bodies and then the support part 13 may be attached to the bottom part 121 of the storage part 12. The lower end of the support part 13 is fixed to the load cell 11 (specifically, to the upper surface of the movable part 1112) by a second fixing device 113.

[0015] A protrusion 153 that protrudes upward from the upper surface of the upper plate 151 of the housing 15 is provided around the hole 152 .

[0016] The restricting member 14 is provided around the support portion 13 with a small gap 141 (1.5 mm in this embodiment) between it and the support portion 13. In this embodiment, the edge of the hole 152 in the upper plate 151 of the housing 15 functions as the restricting member 14. Alternatively, a member separate from the upper plate 151 may be provided as the restricting member 14 around the support portion 13 inside the housing 15 or on the upper plate 151.

[0017] In addition, the scale 10 of this embodiment has a data processing unit that receives the electrical signals output by each strain gauge and converts them into mass values, a control unit that controls various operations of the scale 10, a display (display unit) that displays mass values, etc., an input unit through which the user inputs data when adjusting the zero point, subtracting a tare weight, etc. Each of these units is the same as that of a conventional scale, so a detailed description will be omitted.

[0018] (2) Operation of the scale of this embodiment The operation of the scale 10 of this embodiment will now be described. The operation during weighing is similar to that of a conventional scale, except that a support 13 is interposed between the storage section (weighing pan) 12 and the load cell 11. Specifically, when an object to be weighed is placed on the top surface of the bottom 121 of the storage section 12, gravity acting on the object presses the bottom 121 downward, causing the support 13 to descend, and the lower end of the support 13 presses down the movable section 1112 of the load cell 11. This deforms the beam 1113 of the load cell 11. This deformation of the beam 1113 causes each strain gauge to output an electrical signal, which is received by a data processing unit and converted into a mass value. This mass value corresponds to the mass of the object to be weighed. Note that if the object to be weighed LS is contained in a container B, the resulting mass value is the sum of the mass of the object to be weighed LS and the mass of the container B. Therefore, it is advisable to subtract the mass of the container B as a tare weight before weighing.

[0019] When an object to be weighed (or the object to be weighed and the container combined) having a mass greater than a predetermined upper limit is placed on the bottom surface of the storage section 12, the bottom surface 1211 (the underside of the bottom 121) of the storage section 12 abuts against the convex portion 153 (see Figure 2), thereby preventing a vertical overload from being applied to the movable part 1112 of the load cell 11, thereby preventing plastic deformation of the load cell 11.

[0020] On the other hand, when cleaning or performing maintenance on the scale 10, an operator's hand or the like may collide with the storage unit 12, unintentionally applying an overload in a direction other than the vertical direction to the storage unit 12. The bottom surface 1211 and the convex portion 153 of the storage unit 12 cannot prevent such an overload from being applied to the load cell 11. However, in the scale 10 of this embodiment, when such an overload in a direction other than the vertical direction is applied, the support portion 13 provided between the bottom portion 121 of the storage unit 12 and the movable portion 1112 of the load cell 11 tilts, and when the tilt angle exceeds a predetermined value, a portion 131 (see FIG. 3 ) of the side surface of the support portion 13 comes into contact with the regulating member 14, preventing the support portion 13 from tilting any further.

[0021] This prevents overloads from being applied to the movable part 1112 of the load cell 11 in directions other than the vertical direction, thereby preventing plastic deformation of the load cell 11. Furthermore, when overloads from directions other than the vertical direction are prevented from being applied in this way, the housing part 12 does not come off the scale 10, so there is no need to perform the troublesome task of reinstalling the housing part 12 in its original position.

[0022] Furthermore, in the scale 10 of this embodiment, the lower end of the support portion 13 is fixed to the load cell 11, so that the accommodation portion 12 can be more reliably prevented from coming off the scale 10.

[0023] Furthermore, since it is possible to prevent the storage section 12 from coming off the scale 10 due to an overload in a direction other than the vertical direction even if it is not fixed to the load cell 11 at the lower end of the support section 13, such fixation is not an essential requirement of the present invention.

[0024] Furthermore, the scale 10 of this embodiment uses a storage unit 12 that has a bottom 121 and side edges 122 that have a shape corresponding to the outer shape of the side surface of the container B, so that when weighing the objects LS contained in the container B, it is possible to prevent the container B from being positioned off-center on the bottom 121 of the storage unit 12. This makes it possible to prevent the objects LS contained in the container B from applying an unbalanced load to the storage unit 12. From this point of view, it is also possible to prevent the movable part 1112 of the load cell 11 from being applied with an overload in a direction other than the vertical direction.

[0025] It is not an essential requirement of the present invention that the storage section 12 has the bottom 121 and the side edges 122. For example, in order to weigh objects of various shapes, a weighing pan without side edges may be used instead of the storage section 12.

[0026] The scale 10 according to one embodiment of the present invention and several modifications thereof have been described above, but the present invention is not limited to these embodiments and modifications, and can be modified as appropriate within the scope of the present invention. For example, the present invention can also be applied when a measurement unit using another method, such as an electromagnetic method, is used instead of the load cell 11.

[0027] [Aspect] It will be apparent to those skilled in the art that the above-described exemplary embodiments are examples of the following aspects.

[0028] (Item 1) A balance according to one aspect of the present invention comprises: a measuring unit that converts the applied force into an electrical signal; a storage section for storing the object to be weighed; a rod-shaped support portion provided between a lower portion of the accommodation portion and the measurement portion; a restricting member provided around the support portion to restrict the inclination of the support portion; Equipped with.

[0029] In the scale according to paragraph 1, if an unbalanced load is applied to the housing (including the weighing pan) during cleaning or maintenance, the support part tilts, and this tilt is regulated by the regulating member. This prevents the housing part (weighing pan) from coming off and prevents an overload from being applied to the measuring part.

[0030] (Item 2) The scale according to item 2 is the scale according to item 1, wherein the measuring unit is a load cell.

[0031] According to the scale of paragraph 2, it is possible to prevent an excessive unbalanced load from being applied to the load cell, which is the measuring unit, and therefore it is possible to prevent the strain element of the load cell from being plastically deformed due to such an excessive unbalanced load.

[0032] (Item 3) The scale according to item 3 is the scale according to item 1 or 2, wherein the storage section has a bottom that supports the lower part of the object to be weighed and a side edge that extends upward from the periphery of the bottom.

[0033] According to the scale of paragraph 3, by placing an object to be weighed, which has a shape similar to the space enclosed by the bottom and side edges, on the bottom so that it fits into the space, it is possible to prevent the object from exerting an unbalanced load on the measuring unit, and also to prevent the object from falling out of the accommodation unit.

[0034] (4th paragraph) The scale according to the 4th paragraph is the scale according to any one of the 1st to 3rd paragraphs, wherein the lower end of the support part is fixed to the measuring part.

[0035] According to the scale of paragraph 4, the lower end of the support part is fixed to the measuring part, which more reliably prevents the support part and the storage part in which the support part is provided below from coming off the measuring part. [Explanation of symbols]

[0036] 10...Scale 11...Load cell (measuring part) 111...Strain body 1111...Fixed part of the strain generating body 1112...moving part of the strain generating body 1113...Beam part of the flexure body 112...First fixture 113…Second fixture 12...Storage section 121...Bottom of storage section 1211...Bottom of the storage area 122...Side edge of storage section 13...Support part 131...Part of the support 14...Regulatory member 141...Gap between support part and regulating member 15...Case 151...Top plate of the housing 152...hole provided in the housing 153...Convex part

Claims

1. a measuring unit that converts the applied force into an electrical signal; a storage section for storing the object to be weighed; a rod-shaped support portion provided between a lower portion of the accommodation portion and the measurement portion; a restricting member provided around the support portion to restrict the inclination of the support portion; A scale equipped with:

2. The balance according to claim 1 , wherein the measuring unit is a load cell.

3. 3. The balance according to claim 1, wherein the container comprises a bottom portion for supporting a lower portion of the object to be weighed, and side edges extending upward from the periphery of the bottom portion.

4. 3. The balance according to claim 1, wherein a lower end of the support part is fixed to the measuring part.

Images