Electronic balance

Abstract

To provide an electronic balance capable of changing the vertical position of a partition plate in a weighing chamber, without moving the partition plate out of a windshield.SOLUTION: The electronic balance comprises: a base on which a weighing pan is placed; a windshield for enclosing the weighing pan; and a partition plate movement mechanism for vertically moving a partition plate 41 that vertically partitions a weighing chamber formed by the base and the windshield. The partition plate movement mechanism includes: a columnar member 30 erected in the weighing chamber and having vertically extending guide rails and fixation positioning engagement parts; a holding member 401 for holding the partition plate and being movable along the guide rails, a movement positioning engagement parts provided on the holding member and capable of engaging with the fixation positioning engagement parts; urging members for urging the movement positioning engagement parts toward the fixation positioning engagement parts; and a release member for releasing the state of being urged by the urging member.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an electronic balance. [Background technology]

[0002] In laboratories, electronic balances are used to measure the mass (weight) of objects such as powders. Such electronic balances are equipped with a windshield that surrounds the weighing pan to prevent the effects of convection in the measurement environment, and a weighing chamber is formed inside the windshield. In electronic balances equipped with a windshield, the windshield blocks convection outside the weighing chamber, but the effects of convection occurring inside the weighing chamber can reduce the measurement accuracy. In particular, the minimum value fluctuates greatly due to convection inside the weighing chamber, and it takes time for the convection to settle, so it takes a long time before measurements can be made stably.

[0003] On the other hand, there are various sizes of weighing samples and weighing containers. For example, they range from tall containers such as volumetric flasks to low containers such as medicine wrapping paper. If the weighing chamber is made large, it can accommodate all of these weighing samples and weighing containers, but if the weight to be weighed is small, there is a problem of fluctuation in the measured value due to convection in the weighing chamber as described above. For this reason, Patent Document 1 proposes an electronic balance that reduces the influence of convection during measurement by inserting a partition plate into the weighing chamber to separate the weighing chamber into upper and lower parts and reducing the volume of the weighing chamber including the weighing pan with the partition plate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-58204 A [Patent Document 2] JP 2019-219388 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the electronic balance of Patent Document 1, if the height of the weighing container is higher than the height from the weighing pan to the partition plate, the user removes the partition plate from the weighing chamber. When the partition plate is removed from the weighing chamber, the temperature of the partition plate fluctuates depending on the external environment. Therefore, for example, when the partition plate is reinserted into the weighing chamber to perform weighing using medicine wrapping paper, if the temperature difference between the temperature inside the weighing chamber and the temperature of the partition plate is large, convection occurs in the weighing chamber from the weighing pan to the partition plate. As a result, it takes time for the convection to stabilize.

[0006] Also, Patent Document 2 proposes an electronic balance that does not use a partition plate, but changes the volume of the weighing chamber by moving the upper wall of the windshield in the vertical direction. In this electronic balance, a rear wall of the weighing chamber is provided between the windshield and the housing at the rear of the balance, and the rear wall houses a moving mechanism for moving the upper wall of the windshield up and down. In the case of such an electronic balance, one side of the upper wall is exposed to the outside air, and the temperature of the upper wall is affected by the external environment. Therefore, when the temperature of the external environment fluctuates and the temperature difference between the base on which the weighing pan is placed and the upper wall becomes large, convection occurs in the weighing chamber even if the volume of the weighing chamber is reduced. In that case, it takes time for the convection to stabilize.

[0007] The problem that the present invention aims to solve is to provide an electronic balance in which the up and down position of the partition plate can be changed within the weighing chamber without having to move the partition plate outside the windshield. [Means for solving the problem]

[0008] The electronic balance according to the present invention, which has been made to solve the above problems, comprises: A base on which the weighing pan is placed; A windshield surrounding the weighing pan; a partition plate moving mechanism for vertically moving a partition plate that divides a weighing chamber defined by the base and the windshield into upper and lower portions, The partition plate moving mechanism includes: A column member provided in the weighing chamber and having a guide rail extending vertically and a fixed positioning engagement portion; a holding member that is movable along the guide rail and holds the partition plate; a movable positioning engagement portion provided on the holding member and capable of engaging with the fixed positioning engagement portion; a biasing member that biases the movable positioning engagement portion toward the fixed positioning engagement portion; a release member for releasing the biased state of the biasing member; Equipped with. Effect of the Invention

[0009] According to the present invention, when the biasing member is biasing the moving positioning engagement part toward the fixed positioning engagement part, the moving positioning engagement part engages with the fixed positioning engagement part, and the partition plate held by the holding member is fixed at a predetermined height position with respect to the column member. In addition, the biasing state by the biasing member is released by the release member, and the engagement of the moving positioning engagement part with the fixed positioning engagement part is released, so that the height position of the partition plate can be changed by moving the holding member up and down along the guide rail. When the partition plate is changed to an appropriate height position, the release member stops releasing the biasing state of the biasing member. As a result, the moving positioning engagement part is biased toward the fixed positioning engagement part by the biasing member again, and the moving positioning engagement part engages with the fixed positioning engagement part. Therefore, the partition plate can be fixed at a predetermined height position. In this way, in the present invention, the height of the partition plate can be changed without removing the partition plate from the weighing chamber, so that the convection generated in the weighing chamber can be reduced. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view of an electronic balance according to an embodiment of the present invention. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. 4 is a perspective view of a holder portion in the partition plate unit of the present embodiment. [Diagram 5]FIG. 4 is a perspective view of an operating portion of the partition plate unit of the present embodiment. [Figure 6] FIG. 2 is a perspective view of a partition plate unit according to the present embodiment. [Figure 7] FIG. 4 is a perspective view of the partition plate unit of the present embodiment as viewed from the bottom side. [Figure 8] FIG. 4 is a schematic diagram for explaining the mechanism of the partition plate moving mechanism of the present embodiment. [Figure 9] FIG. 4 is a perspective view of an electronic balance according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] An embodiment of an electronic balance according to the present invention will now be described with reference to the drawings. Fig. 1 is a perspective view of an electronic balance 1 of this embodiment.

[0012] <Overall composition> This electronic balance 1 is a balance capable of measuring the mass (weight) of an object to be measured with a minimum display of 0.1 mg or less. As shown in Fig. 1, the electronic balance 1 comprises a base 10 on which a weighing pan 11 is placed, and a windshield 20 that surrounds the weighing pan 11. The windshield 20 of the electronic balance 1 shown in Fig. 1 is rectangular tubular, but the shape of the windshield 20 may be cylindrical or a polygonal tubular shape other than a rectangular tube. An operation console 12 is provided on the upper front surface of the base 10.

[0013] A weight detection mechanism that supports the weighing dish 11 and detects its weight is disposed below the weighing dish 11 on the base 10. Examples of the weight detection mechanism include an electromagnetic type and a load cell type. In this embodiment, the weighing dish 11 is circular, but it may be rectangular or have another shape, and may include a stand that supports a weighing container.

[0014] The operation console 12 is provided with a display unit that displays weighing values ​​and a number of operation keys that accept input from the user. A rear case 14 is provided on the rear side of the base 10. Various electrical components that control the operation of the electronic balance 1 are arranged inside the base 10 and the rear case 14. A static eliminator 13 is provided in the rear case 14 to remove static electricity from within a weighing chamber 28, which will be described later.

[0015] The windshield 20 comprises a rear case 14 and a front wall 22, a right door 24, a left door 25, and an upper door 26 provided on the front side of the rear case 14. The front wall 22, the right door 24, the left door 25, and the upper door 26 are made of a transparent material such as glass. The front wall 22, the right door 24, the left door 25, and the upper door 26 are supported by a frame 21 provided on the base 10. The space formed by the base 10 and the windshield 20 becomes a weighing chamber 28.

[0016] The front surface of the rear case 14 constitutes the rear wall of the windshield 20 (hereinafter referred to as rear wall 29), and the static eliminator 13 is attached at a position approximately 1 / 3 of the height of this rear wall 29. Grips 27 are provided on each of the right door 24, left door 25, and upper door 26. A user can hold the grips 27 and slide each of the right door 24, left door 25, and upper door 26, for example, in the front-to-rear direction to open and close the doors. By closing the right door 24, left door 25, and upper door 26, the intrusion of airflow from the outside into the weighing chamber 28 is blocked.

[0017] <Partition plate movement mechanism> Next, a partition plate moving mechanism provided in the weighing chamber 28 will be described with reference to FIGS. The weighing chamber 28 is divided into upper and lower sections by a partition plate 41. The partition plate 41 can be made of a transparent material such as a glass plate or a synthetic resin plate, or a metal plate-shaped member. Hereinafter, the space below the partition plate 41 in the weighing chamber 28 is referred to as a weighing space 281, and the space above is referred to as a working space 282. The partition plate moving mechanism changes the volume of the weighing space 281 to a size suitable for the size of the object to be weighed by moving the partition plate 41 up and down. The partition plate moving mechanism includes a pillar member 30 made of a rectangular plate material that is long in the vertical direction, and a partition plate unit 40 that can move in the vertical direction along the pillar member 30 (see FIGS. 1 and 2).

[0018] The pillar member 30 is fixed to the rear wall 29 at a position above the static eliminator 13, for example, via screws 31. A plurality of engagement recesses 32 are formed lined up in the vertical direction at both left and right ends of the front surface of the pillar member 30. The plurality of engagement recesses 32 on the left side correspond to the plurality of engagement recesses 32 on the right side at corresponding heights. The pair of left and right engagement recesses 32 located at the same height are U-shaped grooves in side view for positioning the partition plate 41 at a predetermined height, and the plurality of engagement recesses 32 correspond to the fixed positioning engagement portion of the present invention.

[0019] Side guide grooves 33 extending in the vertical direction are formed on both the left and right side surfaces of the pillar member 30. A central guide groove 34 extending in the vertical direction is formed in the central portion of the front surface of the pillar member 30. Scales are provided on both the left and right sides of the central guide groove 34 as a guide for the height of the partition plate 41. The side guide grooves 33 and the central guide groove 34 function as guide rails of the present invention. The guide grooves may be formed by processing the pillar member 30, or a member (guide rail) having a guide groove other than the pillar member having the engagement recess 32 may be fixed to the pillar member.

[0020] The partition unit 40 comprises a partition 41 and a holding member 401 that holds the partition 41 . The holding member 401 comprises an assembly of a holder portion 42 , an operating portion 450 , and a fixed cover 47 .

[0021] The holder portion 42 is made of a member having an L-shaped cross section and including a support portion 430 and a slider portion 440. The support portion 430 is provided with two holes 431 into which two screws 432 (see FIG. 7) for fixing the partition plate 41 to the holding member 401 are inserted. The partition plate 41 has two through holes 411 corresponding to the two holes 431.

[0022] The slider section 440 is a section for mounting the partition plate unit 40 to the pillar member 30, and is made of a member that is substantially U-shaped in plan view, having a first plate section 441 that is erected on the rear end of the support section 430 and has approximately the same width as the pillar member 30, and a pair of second plate sections 442 that extend rearward from both the left and right ends of the first plate section 441. A middle guide pin 444 and an outer guide pin 443 are provided on the side surfaces of the first plate section 441 and the second plate section 442, which form the inner surfaces of the U-shape. Slider section 440 When the slider 440 is attached to the column member 30, the middle guide pin 444 is inserted into the central guide groove 34 of the column member 30, and the outer guide pin 443 is inserted into the side guide groove 33 of the column member 30. The outer guide pin 443 and the middle guide pin 444 are cylindrical pins with diameters slightly smaller than the widths of the side guide grooves 33 and the central guide groove 34, respectively (at least 90% or more of the groove width, preferably 99% or more), and two of each are provided vertically aligned. In addition, long holes 445 are provided at the left and right corners of the front surface of the slider 440, which extend in the left-right direction of the first plate 441 and in the front-rear direction of the second plate 442. The long holes 445 have a shape and size that allow the movement of a movable pin 455 provided in the operation unit 450 described later.

[0023] The operation portion 450 has an annular portion 451 having a rectangular shape in a plan view, and a pair of sliding contact portions 452 provided at the rear end portions of both longitudinal sides of the annular portion 451. The annular portion 451 has substantially the same width as the first plate portion 441 of the slider portion 440. 2When placed on the support portion 430, the pair of sliding contact portions 452 are configured to sandwich the slider portion 440 from both the left and right sides. The sliding contact portions 452 are provided with cylindrical movable pins 455 (see Figs. 7 and 8) that can be inserted into elongated holes 445 provided in the slider portion 440. The movable pins 455 correspond to the moving positioning engagement portion in the present invention. Cylindrical portions 453 are provided on the left and right portions of the front end surface of the annular portion 451, and these cylindrical portions 45 3 A compression coil spring 454 (see FIG. 8) serving as a biasing member is inserted into the cylindrical portion 453. The compression coil spring 454 has a length (free height) such that its tip protrudes from the cylindrical portion 453 when no load is applied. The biasing member may be made of an elastic material such as rubber.

[0024] The fixed cover 47 has a rectangular ring-shaped handle 471 that covers the entire operation unit 450, and a pair of support frames 472 that extend in the left-right direction from the rear of the left and right side surfaces of the handle 471. Female screw holes (not shown) are formed in the lower surfaces of the front left and right corners of the handle 471 at locations corresponding to the hole 431 of the support unit 430. The partition plate 41 is placed on the support unit 430 of the holder unit 42 so that the hole 431 and the through hole 411 match, and further, the ring-shaped portion 451 is placed on the partition plate 41 with the sliding portion 440 sandwiched between the sliding contact portion 452 of the operation unit 450, and the handle 471 of the cover member 47 is placed on the operation unit 450. Then, a screw 432 is inserted through the hole 431 of the support part 430 and the through hole 411 of the partition plate 41 from the underside of the support part 430, and the screw 432 is screwed into the female screw hole of the handle 471. 2 With the partition plate 41 and the operating unit 450 sandwiched between the support part 430 and the handle 471 of the cover member 47, the support part 430 and the handle 471 are fixed to form the partition plate unit 40. At this time, the support frame 472 of the cover member 47 is disposed so as to follow the rear side of the partition plate 41.

[0025] When the handle 471 of the fixed cover 47 is placed on the operating part 450, the front end of the compression coil spring 454 protruding from the cylindrical part 453 abuts against the inner surface of the front part of the handle 471 and receives a compression load from the handle 471. This biases the operating part 450 toward the slider part 440, and the movable pin 455 provided on the sliding part 452 is biased backward. Therefore, in this embodiment, the compression coil spring 454 functions as the biasing member of the present invention. Note that when the handle 471 is simply placed on the operating part 450 (i.e., when the handle 471 and the operating part 450 are not being operated), the compression coil spring 454 is compressed, but its front end protrudes from the cylindrical part 453.

[0026] <Attachment of Partition Unit 40 to Pillar Member 30> The partition plate unit 40 is attached to the column member 30 as follows. First, the outer guide pin 443 is inserted into the side guide groove 33 of the pillar member 30, and the middle guide pin 444 is inserted into the central guide groove 34 of the pillar member 30. Next, the left and right movable pins 455 are inserted into either the left or right engagement recesses 32. At this time, the movable pin 455 is pushed backward by the biasing force of the compression coil spring 454 and positioned near the rear end of the long hole 445, and penetrates deeply into the engagement recess 32, and the movable pin 455 and the engagement recess 32 engage with each other (see FIG. 8). As a result, the partition plate 41 is positioned at a certain height (first height) relative to the pillar member 30.

[0027] <Movement of partition plate 41> The user opens one of the right door 24, the left door 25, and the upper door 26, and inserts his / her hand into the working space 282 above the partition plate 41 in the weighing chamber 28. Then, the user grasps the annular portion 451 and the handle 471 of the operating unit 450, and moves the annular portion 451 toward the front end side of the handle 471 against the biasing force of the compression coil spring 454. Then, as shown by the imaginary line in FIG. 8, the movable pin 455 moves forward, and the engagement of the movable pin 455 with the engagement recess 32 is released. That is, in this embodiment, the operating unit 450 and the handle 471 function as a release member. In this state, the partition plate unit 40 is lifted upward or pushed downward. As a result, the outer guide pin 443 and the middle guide pin 444 slide in the side guide groove 33 and the central guide groove 34, respectively, and the partition plate unit 40 moves up and down along the pillar member 30. Then, with the partition plate 41 positioned at the desired height, the user releases his / her hands from the annular portion 451 and the handle 471. This causes the movable pin 455 to move rearward within the elongated hole 445 of the holder portion 42 by the biasing force of the compression coil spring 454, and engage with the engagement recess 32. As a result, the partition plate 41 is positioned at a height (second height) different from the above-mentioned first height, and the volume of the weighing space 281 is changed.

[0028] In this manner, in this embodiment, the user can change the height of the partition plate 41 by inserting his / her hand into the working space 282 and operating the annular portion 451 and the handle 471. Therefore, there is no need to move the partition plate 41 out of the weighing chamber 28 or touch the partition plate 41 in order to change the weighing space 281 in accordance with the size of the weighing sample, weighing container, or the like, and the occurrence of convection caused by the temperature difference between the partition plate 41 and the weighing space 281 due to a temperature change in the partition plate 41 can be reduced.

[0029] In addition, when the movable pin 455 is engaged with the engagement recess 32, a force moment is generated from the engagement portion between the slider portion 440 and the column member 30 due to the weight of the partition plate 41. In contrast, in this embodiment, two cylindrical outer guide pins 443 are arranged vertically on the slider portion 440, and these outer guide pins 443 are slidably engaged with the side guide grooves 33 on both the left and right sides of the column member 30. When the above-mentioned force moment is generated, the upper and lower outer guide pins 443 abut against the inner wall surfaces of the side guide grooves 33 at points P1 and P2, respectively. Therefore, even if a force moment is generated, the partition plate 41 can be positioned almost horizontally. In addition, when the movable pin 455 is released from the engagement with the engagement recess 32, the abutment state of the outer guide pins 443 against the inner wall surfaces of the side guide grooves 33 is released, so that the partition plate unit 40 can be moved up and down along the column member 30 with a relatively small force.

[0030] In the above embodiment, the two cylindrical outer guide pins 443 are arranged vertically, but the shape and number of the outer guide pins are not limited to this. As long as the shape can be engaged with the inner wall surface of the side guide groove 33 at two points, the outer guide pins may be, for example, a columnar shape with a vertically long ellipse or rectangle in cross section.

[0031] In the above embodiment, the fixed positioning engagement portion is a plurality of engagement recesses 32, and the movable positioning engagement portion is a movable pin 455, but the recessed and projecting shapes of the fixed positioning engagement portion and the movable positioning engagement portion may be reversed or may be of a different shape. Also, the engagement between the fixed positioning engagement portion and the movable positioning engagement portion may be achieved by a friction force other than the engagement between a recess and a projection. of Frictional engagement or magnetic engagement may be used. In the case of frictional engagement or magnetic engagement, it is possible to realize it without providing a plurality of engagement recesses as in the above embodiment. Furthermore, the relationship between the side guide groove 33, the central guide groove 34, the outer guide pin 443, and the middle guide pin 444 is not limited to the above embodiment as long as they are shaped to engage with each other.

[0032] It has been known that when airflow in the weighing space caused by opening and closing the windshield door or the temperature difference between the inside and outside of the weighing space contacts the glass wall surrounding the weighing space, static electricity is generated on the surface of the glass wall, which may cause errors during sensitivity calibration (adjustment) and measurement. For this reason, in the above embodiment, the static eliminator 13 is disposed on the rear wall 29 of the windshield 20 to eliminate static electricity in the weighing space 281. In this case, the static eliminator 13 is attached at a position about 1 / 3 of the height of the rear wall 29, and the pillar member 30 is fixed to the rear wall 29 above the static eliminator 13, so that the static eliminator 13 is located within the weighing space 281 regardless of the position of the partition plate 41, and the static eliminator 13 can eliminate static electricity.

[0033] 9 shows an electronic balance 1A according to another embodiment of the present invention. In this electronic balance 1A, an opening 412 for inserting and removing a sample is formed, for example, approximately in the center of a partition plate 41. The rest of the configuration is the same as that of the electronic balance 1 described above, so a description thereof will be omitted.

[0034] By providing the opening 412 in the partition 41, for example, after opening the upper door 26 and inserting one's hand into the working space 282 to move the partition unit 40 up and down, one can directly (without opening the front door 22, the right door 24, or the left door 25) put a sample in and take it out of the weighing space 281 through the opening 412. This makes it possible to suppress the occurrence of convection in the weighing space 281 and reduce the effects of convection during measurement.

[0035] [Aspects] It will be appreciated by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0036] (Section 1) A base on which the weighing pan is placed; A windshield surrounding the weighing pan; a partition plate moving mechanism for vertically moving a partition plate that divides a weighing chamber formed by the base and the windshield into upper and lower portions, The partition plate moving mechanism includes: a column member provided in the weighing chamber and having a guide rail extending vertically and a fixed positioning engagement portion; a holding member that is movable along the guide rail and holds the partition plate; a movable positioning engagement portion provided on the holding member and capable of engaging with the fixed positioning engagement portion; a biasing member that biases the movable positioning engagement portion toward the fixed positioning engagement portion; a release member for releasing the biased state of the biasing member; It is an electronic balance equipped with

[0037] In the electronic balance of paragraph 1, when the biasing member is biasing the movable positioning engagement part toward the fixed positioning engagement part, the movable positioning engagement part engages with the fixed positioning engagement part, and the partition plate held by the holding member is fixed at a predetermined height position with respect to the column member. In addition, the biasing state by the biasing member is released by the release member, and the engagement of the movable positioning engagement part with the fixed positioning engagement part is released, so that the height position of the partition plate can be changed by moving the holding member up and down along the guide rail. When the partition plate is changed to an appropriate height position, the release member stops releasing the biasing state of the biasing member. As a result, the movable positioning engagement part is biased toward the fixed positioning engagement part by the biasing member again, and the movable positioning engagement part engages with the fixed positioning engagement part. Therefore, the partition plate can be fixed at a predetermined height position. In this way, in the present invention, the height of the partition plate can be changed without removing the partition plate from the weighing chamber, so that the convection generated in the weighing chamber can be reduced.

[0038] (Section 2) In the electronic balance in paragraph 1, The fixed positioning engagement portion may be composed of a plurality of engagement recesses provided at different positions above and below the pillar member.

[0039] In the electronic balance of paragraph 2, the partition plate can be positioned at an appropriate position by engaging the movable positioning engaging portions with the multiple engaging recesses.

[0040] (Section 3) In the case of electronic balances under paragraph 1 or 2, The guide rail is a guide groove formed in the pillar member, The holding member is preferably provided with two upper and lower convex members which slidably engage with the guide grooves.

[0041] In the electronic balance of paragraph 3, when the movable positioning engagement part is engaged with the fixed positioning engagement part, the moment of force acting on the engagement part between the sliding part and the guide rail due to the weight of the partition plate is countered by the reaction force generated by the convex member being engaged with the guide groove of the guide rail. This makes it possible to reliably position the partition plate. Also, when the movable positioning engagement part is disengaged from the fixed positioning engagement part, the convex member moves in the guide groove as the sliding part moves.

[0042] (Section 4) In any of the electronic balances described in paragraphs 1 to 3, The partition plate has an opening for inserting and removing a sample.

[0043] According to the electronic balance of paragraph 4, a sample can be placed on the weighing pan or removed from the weighing pan through the opening.

[0044] (Section 5) For the electronic balances in items 1 to 4, The windshield further includes a static eliminator provided on a rear wall thereof, The pillar member may be fixed to the rear wall above the static eliminator.

[0045] In the electronic balance of paragraph 5, the pillar members are disposed above the static eliminator on the rear wall, so the partition plate moves in the space above the static eliminator in the weighing chamber. When airflow in the weighing chamber caused by opening and closing the windshield door or temperature differences comes into contact with the glass wall that forms the weighing chamber, static electricity is generated on the glass surface, which may cause errors in the calibration (adjustment) of the sensitivity or during weighing. However, with this configuration, it is possible to always obtain the static elimination effect of the static eliminator in the weighing space below the partition plate in the weighing chamber. And, by quickly removing static electricity with the static eliminator, stable weighing can be performed. [Explanation of symbols]

[0046] 1...Electronic balance 10…Foundation 11...Measuring pan 12...Operation console 13...Static eliminator 14…Rear case 20…Windshield 21...Frame 22…Front wall 24...Right side door 25…Left door 26...Upper door 27…Grip 28…Weighing room 281...Weighing space 282…Work space 29…Back wall 30...Column member 31…Screw 32...Engagement recess 33...Side guide groove 34...Central guide groove 40...Partition unit 401... Retaining member 41…Partition plate 412…Aperture 42…Holder part 430...Support part 431...hole 432…Screw 440…Slider section 441...1st plate part 442…Second plate part 443…Outer guide pin 444…Middle guide pin 445…Long hole 450...Operation unit 451…Circular section 452...Sliding contact part 453…Cylindrical section 454…Spring 455…Movable pin 47…Fixed cover 471…Handle 472…Support frame

Claims

1. A base on which the weighing pan is placed; a windshield surrounding the weighing pan, the windshield being formed by a side wall and an upper door; a partition plate moving mechanism for vertically moving a partition plate that divides a weighing chamber formed by the base and the windshield into upper and lower portions, The partition plate moving mechanism includes: A pillar member erected in the weighing chamber; A guide rail extending in the vertical direction from the pillar member; A plurality of engagement recesses are provided at different positions in the vertical direction of the pillar member; a holding member that is movable along the guide rail and holds the partition plate; an engagement pin provided on the holding member and capable of engaging with the plurality of engagement recesses; a biasing member that is made of an elastic member and biases the engagement pin toward the engagement recess by elastic force; a release member for releasing the biased state of the biasing member; An electronic balance equipped with:

2. 2. The electronic balance according to claim 1, The guide rail is a guide groove formed in the pillar member, The holding member is provided with two upper and lower convex members that slidably engage with the guide grooves.

3. 3. The electronic balance according to claim 1, The partition plate has an opening for inserting and removing a sample.

4. The electronic balance according to any one of claims 1 to 3, The windshield further includes a static eliminator provided on a rear wall thereof, The pillar member is fixed to the rear wall above the static eliminator.

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