Electronic balance

Abstract

To downsize an electronic balance for automatically opening and closing a pair of right and left slide doors of a windshield constituting a weighing chamber.SOLUTION: A windshield 8 having a pair of right and left slide doors 13 and 14 is provided above a housing case 5 in which a weighing mechanism connected to a weighing pan 2 is disposed. The slide doors 13 and 14 are slidably suspended and supported, and are linked with each other so as to be engaged / disengaged at mutual lower parts by a linking mechanism composed of connecting members 31 and 32, engaging / disengaging members 33 and 34 and a connecting plate 60. An air cylinder having a piston rod connected to the connecting plate 60 and a pump as a driving source of the air cylinder are provided in the housing case 5. Since it is not necessary to separately provide a space for housing the air cylinder and the pump, the electronic balance 1 can be downsized.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electronic balance that automatically opens and closes sliding doors, which are a pair of left and right side panels of a windshield that forms a weighing chamber. [Background technology]

[0002] Various mechanisms have been proposed for automatically opening and closing sliding doors, which are a pair of left and right side panels of a windshield that forms a weighing chamber. For example, Patent Document 1 discloses a precision balance in which a sliding window, which is a side panel, is movably supported below the weighing chamber and is synchronously movable laterally by a locking grip fixed to the panel, and the panel is connected to a motor drive unit that moves the panel. The motor drive unit is located in a scale case that is approximately the same size as the weighing chamber and houses a weighing mechanism located at the rear of the weighing chamber. The motor drive unit is fixed to the rear wall of the weighing chamber, and a pinion fixed to the tip of the motor's rotary drive shaft engages with a rack on the panel. As a result, rotation of the rotary drive shaft of the motor drive unit moves the panel in the forward and backward directions of the weighing chamber, and moves the sliding window in the same direction to open and close it. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 62-140328 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the precision balance in Patent Document 1 houses the motor drive unit in a balance case located at the rear of the weighing chamber, which makes the precision balance larger in the front-to-rear direction due to the presence of the case, making it difficult to reduce its size.The present invention has been made in consideration of this problem, and its object is to provide an electronic balance that can be reduced in size and is equipped with a windshield that has a pair of sliding doors that are side panels that open and close automatically. [Means for solving the problem]

[0005] In order to achieve the above-mentioned object, a first preferred embodiment of the electronic balance of the present invention comprises a storage case in which a weighing mechanism connected to a weighing pan is placed, a windshield having a top panel, a front panel, a back panel, and a pair of left and right side panels to cover the weighing pan above the storage case and form a weighing chamber, at least the pair of left and right side panels being sliding doors that can slide in the front-to-back direction of the storage case, a pair of hanging mechanisms that slidably suspend and support each of the pair of left and right sliding doors, a linking mechanism that links the pair of left and right sliding doors at their lower parts so that they can be engaged and disengaged, and an air cylinder that is arranged within the storage case and links a piston rod with the linking mechanism and slides the pair of left and right sliding doors via the linking mechanism.

[0006] With this configuration, the air cylinder rod is linked to a linkage mechanism that links the pair of left and right sliding doors, so that by driving the air cylinder to extend or retract its piston rod, the pair of left and right sliding doors can be automatically slid in tandem.In addition, because the air cylinder is installed in a storage case located below the weighing chamber, the case installed behind the weighing chamber that houses the conventional weighing mechanism and motor drive mechanism is no longer necessary.Furthermore, by linking only one of the pair of left and right sliding doors to the linkage mechanism, it is possible to slide only that one sliding door.

[0007] In addition to the first embodiment, a second embodiment includes a pump that serves as the drive source for the air cylinder and is located inside the storage case. This embodiment allows for even greater miniaturization of the electronic balance. Furthermore, since there is no need to install the pump separately from the storage case, the overall system is more convenient to use.

[0008] In a third embodiment, in addition to the configuration of the second embodiment, the air cylinder and the pump are arranged one above the other inside the housing case, which makes it possible to minimize the area occupied by the air cylinder and the pump inside the housing case.

[0009] In addition to the configuration of the second embodiment, a fourth embodiment is characterized in that the air cylinder and the pump are arranged side by side within the housing case, thereby minimizing the height of the air cylinder and the pump within the housing case. [Effects of the Invention]

[0010] The electronic balance of the present invention eliminates the need for the extra case that was located at the rear of the weighing chamber, making it possible to reduce the size of the balance. In addition, the sliding doors, which are a pair of left and right side panels that make up the windshield, can be opened and closed automatically, either together or separately. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a perspective view showing an electronic balance according to a first embodiment of the present invention with one sliding door open. [Figure 2] FIG. 2 is a partially omitted perspective view showing a hanging mechanism. [Figure 3] FIG. 10 is a partially omitted perspective view showing the linked state of the air cylinder and the engaging / disengaging member. [Figure 4] FIG. 10 is a partially omitted perspective view showing the arrangement of the air cylinder within the lower case frame. [Figure 5] FIG. 10 is a perspective view showing a connecting member fixed to a sliding door. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] FIG. 3 is a partially omitted perspective view showing the arrangement of the pump in the housing case. [Figure 9] FIG. 3 is a block diagram showing the connection relationship between the air cylinder, the pump, and the solenoid valve. [Figure 10] FIG. 10 is a perspective view showing the arrangement of an air cylinder, a pump, and an electromagnetic valve according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] A first embodiment of the present invention will now be described with reference to the accompanying drawings. As shown in FIG. 1, electronic balance 1 includes a storage case 5 made up of a lower case frame 3 having a bottom plate 3a (see FIG. 4) that houses a weighing mechanism (not shown), including a mass sensor such as an electromagnetic balance or load cell connected to a weighing pan 2, and an upper case frame 4 having a top plate. The weighing pan 2 is located above a floor plate 6 that also serves as the top plate of the upper case frame 4. The electronic balance 1 also includes a windshield 8 above the storage case 5 that covers the weighing pan 2 to form a weighing chamber 7. A ring-shaped windshield ring 21 is fixed to the top surface of the floor plate 6 to prevent the weighing pan 2 from being affected by wind. A control panel 9 is provided on the front side of the storage case 5. The control panel 9 includes a display 91 on its top surface that displays weighing results and status, and multiple touch-panel operation switches 92.

[0013] The windshield 8 prevents airflow during weighing, such as that generated by an air conditioner, a person's breathing during weighing, or a person walking, from acting as wind pressure on the load-bearing portion centered on the weighing pan 2 and affecting the weighing result. The windshield 8 includes a top panel 10, a front panel 11, a back panel 12, and a pair of left and right sliding doors 13 and 14. The top panel 10, the right sliding door 13, and the left sliding door 14 are slidable in the front-to-rear direction of the storage case 5. The pair of left and right sliding doors 13 and 14 open and close automatically. The top panel 10 is equipped with a handle 15 that can be gripped when manually sliding. The top panel 10, the front panel 11, the back panel 12, and the left and right sliding doors 13 and 14 are made of transparent glass or resin so that the interior can be observed. To prevent static electricity, the glass is preferably conductive glass with a conductive film on its surface, and the resin is preferably conductive resin.

[0014] The lower end of the front panel 11 is fixed to the floor panel 6, and the corners of its upper end are fixed to the front end surfaces of a pair of support cases 16, 17, which are provided above the windshield 8 and have openings at the widthwise center of their bottom surfaces along the longitudinal direction. The rear ends of the pair of support cases 16, 17 are fixed to the upper ends of support plates 18, 19, whose lower ends are fixed to the floor panel 6. In FIG. 1, only the lower end of the support plate 18 and the upper end of the support plate 19 are visible. The rear panel 12 has both side ends fixed to the support plates 18, 19, its lower end fixed to the floor panel 6, and both corners of its upper end fixed to the support cases 16, 17. The top panel 10 is guided at both ends by guide rails 22, 23 (only shown for support case 17) provided on the opposing outer surfaces of the support cases 16, 17, and can slide in the front-to-back direction of the electronic balance 1. When positioned at the rearmost position, the top surface of the weighing chamber 7 is completely open, while when positioned at the frontmost position abutting the top of the front panel 11, the top surface of the weighing chamber 7 is closed.

[0015] Next, the left and right sliding doors 13, 14 will be described together with their hanging mechanisms. The right sliding door 13 and the left sliding door 14 have the same configuration and are arranged symmetrically. Only the door 13 will be described, and a description of the left sliding door 14 will be omitted.

[0016] 1 and 2, the right sliding door 13 has a protective frame 25 around its periphery. The upper left side of this protective frame 25 (the side facing the front panel 11) is bent into a crank-like shape as a bent portion 25a so as to expose the upper left corner of the right sliding door 13, and the upper center of the protective frame 25 has a notched portion 25b that divides it into left and right halves. An auxiliary plate 26 having an L-shaped planar shape is fixed to the left side of the protective frame 25, and the auxiliary plate 26 comes into contact with the front panel 11 when the right sliding door 13 is closed.

[0017] As shown in FIG. 2, a guide member 27 having bearing portions 27a and 27b is fixed to the upper surface of the protective frame 25. The end of the guide member 27 on the front plate 11 side extends downward and is fixed on the bent portion 25a. Guide rollers 28 and 29, each having a pair of rollers 28a and 28b and 29a and 29b, are rotatably supported by the bearing portions 27a and 27b on their respective rotation shafts. The rollers 28a, 28b, 29a, and 29b of the guide rollers 28 and 29 are placed on guide rails 30a provided at the lower ends of a pair of fixed frames 30 (only the rollers 28a and 29a are shown) provided inside the support case 16 so as to face each other. As a result, the right sliding door 13 is suspended and supported by the support case 16, and the lower end of the right sliding door 13 is positioned slightly away from the floor board 6. When the rollers 28a, 28b, 29a, and 29b rotate, the right sliding door 13 moves in the front-rear direction via the guide member 27 and the protective frame 25 according to the direction of rotation.

[0018] Next, a linking mechanism that links the pair of right sliding doors 13, 14 at their lower parts so that they can be engaged and disengaged will be described. As shown in Fig. 1, engaging and disengaging members 33 and 34 (see Figs. 3 and 4) are engaged in an engaging and disengaging manner with connecting members 31 and 32, which also serve as handles for the left and right sliding doors 13 and 14. The engaging and disengaging members 33 and 34 and the connecting members 31 and 32 have the same configuration, so only the configuration of the connecting member 31 and the engaging and disengaging member 33 on the right sliding door 13 side will be described, and as for the configuration on the sliding door 14 side, the corresponding components will be denoted by the same reference numerals and a detailed description thereof will be omitted.

[0019] 5, the connecting member 31 has a fixing portion 31a and a block-shaped connecting portion 31c provided with an oval hole 31b extending upward from the bottom surface. As shown in FIGS. 1 and 5, the connecting member 31 is fixed to the auxiliary plate 26 side of the protective frame 25 of the right sliding door 13 so that the fixing portion 31a is positioned obliquely in the closing movement direction of the right sliding door 13.

[0020] As shown in FIG. 6, the engaging / disengaging member 33 includes a housing body 41 having an overall rectangular shape, a movable body 42 slidably disposed within the housing body 41 in the longitudinal direction, and a housing cover 43 having a U-shaped cross section and fixed to the housing body 41 so as to close one of its open faces. Semicircular cross-sectional grooves 44a, 44b and 45a, 45b are formed in the inner surfaces of a pair of opposing side walls of the housing body 41, spaced apart in the longitudinal direction. A circular hole 46 is formed in one side wall located at the longitudinal end of the housing body 41. A rectangular through-hole 47 is formed in the housing cover 43. As shown in FIGS. 3 and 4, the housing cover 43 is fixed to a frame-shaped support 56 having an upper surface 57. A circular hole 58 is formed in the upper surface 57 of the support 56. The engaging and disengaging member 33 and the engaging and disengaging member 34 on the left sliding door 14 side are fixed at the lower end of the support body 56 to both ends of a connecting plate 60 that extends along the outer surface of the bottom plate 3 a of the lower case frame 3 .

[0021] As shown in FIG. 6 , the movable body 42 has a rectangular parallelepiped main body 48, which is provided with a cylindrical protrusion 49 and an operation knob 50. The movable body 42 has a horizontal hole 51 penetrating laterally at a position corresponding to the operation knob 50. Positioning members 53a, 53b, each having a pair of hemispherical tips and a cylindrical base, are disposed within the horizontal hole 51 and are resiliently biased outwardly of the horizontal hole 51 by a coil spring 52. The positioning members 53a, 53b are resiliently contacted by the resilience of the coil spring 52 with the inner surface of the side wall of the housing main body 41, which is provided with grooves 44a, 44b, 45a, and 45b. The operation knob 50 protrudes from a through hole 47 in the housing cover 43, and the protrusion 49 protrudes from and fits into a circular hole 46 in the housing main body 41. The circular hole 46 is positioned corresponding to a circular hole 58 formed in the top surface 57 of a support 56. The main body 48 is provided with rectangular holes 54 and 55 extending parallel to the horizontal hole 51 in order to reduce the weight.

[0022] As shown in Fig. 7, by gripping the operation knob 50 and moving it within the through-hole 47, the main body 48 of the movable body 42 moves within the housing main body 41 while the positioning members 53a, 53b elastically contact the inner surface of the side wall of the housing main body 41, causing the protrusion 49 to protrude or retract through the circular hole 46 (see Fig. 6) depending on the direction of movement. During this movement, the state in Fig. 7(c) where the positioning members 53a, 53b engage with the recessed grooves 44a, 44b is the most protruding position of the protrusion 49, and the state in Fig. 7(a) where the positioning members 53a, 53b engage with the recessed grooves 45a, 45b is the most retracted position of the protrusion 49, and the movable body 42 is positioned at these two positions.

[0023] Therefore, when the operating knob 50 of the corresponding connecting member 31 and engaging / disengaging member 33, which is in the state shown in FIG. 7(a), is moved upward in FIGS. 1 and 3, the positioning members 53a and 53b are disengaged from the grooves 45a and 45b, and then, via the state shown in FIG. 7(b), are engaged with the grooves 44a and 44b, resulting in the state shown in FIG. 7(c). The protrusion 49 protrudes most from the housing body 41 and enters the hole 31b of the connecting member 31, achieving the engaged state shown in FIG. 1. Since the hole 31b has an elliptical planar shape, positioning of the protrusion 49 during the insertion operation is easy. By engaging the pair of left and right sliding doors 13 and 14, the right sliding doors 13 and 14 are linked and can be automatically opened and closed in conjunction with each other. Furthermore, by engaging only one of the left and right sliding doors 13 and 14, the engaged sliding door can be automatically opened and closed.

[0024] Next, the air cylinders that open and close the left and right sliding doors 13, 14 and their drive sources will be described. As shown in FIG. 8, a cylinder box 62 with an open bottom is provided along the right side wall 3b at the bottom of the lower case frame 3. As shown in FIGS. 3 and 4, an air cylinder 63, which serves as a drive means for opening and closing the left and right sliding doors 13 and 14, is housed in the cylinder box 62 and positioned parallel to the left and right sliding doors 13 and 14. The air cylinder 63 is fixed in a U-shaped cross-section holding frame 64 (see FIG. 3) having a pair of left and right fixing claws 65a, 65b and 66a, 66b protruding from the upper surface of each end of the air cylinder 63. The fixing claws 65a, 65b and 66a, 66b are inserted into and locked into locking holes (not shown) in a top plate 67 of the cylinder box 62, thereby securing the air cylinder 63 to the cylinder box 62. By disposing the air cylinder 63 in the cylinder box 62, it is possible to prevent dust from entering the weighing chamber 7 and prevent air vibrations from being transmitted from the air cylinder 63 to the weighing chamber 7.

[0025] As shown in Figure 9, the air cylinder 63 is a double-acting type, and the reciprocating motion of the piston rod 68 is performed both forward and backward by air pressure. For this reason, ports for supplying air into the air cylinder 63 are provided at two locations, front and rear. A rearward port 90 is provided at the front of the cylinder tube 69, which has a piston (not shown) with the piston rod 68 mounted therein, for moving the piston rod 68 rearward by the supplied air. Similarly, a forward port 91 is provided at the rear of the cylinder tube 69 for moving the piston rod 68 forward.

[0026] 3 and 8, piping tube 71 connected to reverse side port 90 is connected to a first pump 74 attached to the top plate 67 of the cylinder box 62 via a connecting pipe 72 and a piping tube 73. Furthermore, piping tube 75 connected to forward side port 91 is connected to a second pump 78 attached to the top plate 67 of the cylinder box 62 via a connecting pipe 76 and a piping tube 77. The first pump 74 is connected to a first solenoid valve 80 that controls the stopping of air flow via the piping tube 73, the connecting pipe 72, and a piping tube 79. Furthermore, the second pump 78 is connected to a second solenoid valve 82 that controls the stopping of air flow via the piping tube 77, the connecting pipe 76, and a piping tube 81. The first solenoid valve 80 is fixed to the first pump 74 by a fixing plate 95 fixed vertically to the top plate 67, and the second solenoid valve 82 is fixed to the second pump 78 by a fixing plate 96 fixed vertically to the top plate 67. The pumps 74, 78 are arranged above the air cylinder 63 in a state where they are stacked vertically relative to the air cylinder 63, and the parts of them excluding their lower parts are positioned corresponding to the upper case frame 4 of the storage case 5.

[0027] 9 is a block diagram showing the connection relationship between the air cylinder 63, the pumps 74, 78, and the solenoid valves 80, 82. The first pump 74 and the second pump 78 are both air pumps. The first pump 74 and the second pump 78 are the drive sources for the air cylinder 63, compressing air and sending it to the air cylinder 63. The air pressure moves the piston, opening and closing the sliding doors 13, 14 via the connecting plate 60, the engaging and disengaging members 33, 34, and the connecting members 31, 32 connected to the piston rod 68. The outlet sides of the first solenoid valve 80 and the second solenoid valve 82 are open to the atmosphere, and the opening and closing of the valves controls the blocking of air flow. The second pump 78 is connected to a forward port 91 provided behind the air cylinder 63, which branches off midway and is connected to the second solenoid valve 82. A first pump 74 is connected to a reverse port 90 provided in front of the air cylinder 63, and the port 90 branches off midway, to which a first electromagnetic valve 82 is connected.

[0028] Here, the link between the air cylinder 93 and the link mechanism will be described. As shown in FIGS. 3 and 4, the piston rod 68 of the air cylinder 63 has a male thread (not shown) formed at its tip, which threads into a female thread 84a formed in a raised portion 84 at one end of a guide plate 83. As shown in FIG. 4, the guide plate 83 has an engaging protrusion 83a on its bottom surface that engages with a guide hole 85 formed in the bottom plate 3a of the lower case frame 3 along the right side wall 3b, corresponding to the open bottom of the cylinder box 62, and is guided and movable by this guide hole 85. The bottom plate 3a of the lower case frame 3 also has a guide hole 86 formed along the left side wall 3c, extending parallel to the guide hole 85. A guide plate 87 engages with this guide hole 86 via an engaging protrusion 87a on its bottom surface, and the guide plate 87 is movable along the guide hole 86. The guide plate 87 has the same configuration as the guide plate 83, except for the presence or absence of the raised portion 84. The one guide hole 86 and the guide plate 87 are covered by covers 88a, 88b (see FIG. 8) provided on the bottom plate 3a to allow movement of the guide plate 87. The other guide hole 85 is covered by the cylinder box 62, so no cover is necessary.

[0029] The bottom surfaces of the guide plates 83, 87 exposed to the outside through the guide holes 85, 86 are fixed to connecting plates 60 extending perpendicular to the guide holes 85, 86 along the outer surface of the bottom plate 3a of the lower case frame 3. Both ends of the connecting plate 60 are located outside the side walls 3b, 3c of the storage case 5 and are fixed to the lower ends of the corresponding engaging and disengaging members 33, 34. As described above, the engaging and disengaging members 33, 34 engageably and disengageably link the connecting plate 60 to the pair of right sliding doors 13, 14, and are engagedly and disengageably with the connecting members 31, 32 that also serve as handles for the right sliding doors 13, 14.

[0030] Next, the opening and closing operations of the left and right sliding doors 13, 14 in this embodiment will be described. First, with each sliding door 13, 14 closed, the connecting members 31, 32 and the engaging and disengaging members 33, 34 on the sliding door 13, 14 to be automatically opened and closed are engaged. If the left and right sliding doors 13, 14 are to be opened and closed in conjunction with each other, the connecting members 31, 32 and the engaging and disengaging members 33, 34 of each sliding door 13, 14 are engaged. Then, when the second solenoid valve 82 is opened, the first solenoid valve 80 is closed, and the first pump 74 is operated, air flows in from the rearward-side port 90 of the air cylinder 63 and is pressurized. As a result, the piston rod 68 enters the cylinder tube 69, and the guide plate 83, the connecting plate 60, and the guide plate 87 also move in the same direction. As a result, each sliding door 13, 14 moves rearward (toward the back panel 12) via the engaging and disengaging members 33, 34 and the connecting members 31, 32, and enters an open state. On the other hand, when closing each of the sliding doors 13, 14, the first solenoid valve 80 is opened, the second solenoid valve 82 is closed, and the second pump 78 is operated. In contrast to the above, the piston rod 68 protrudes from inside the cylinder tube 69, and each of the sliding doors 13, 14 moves forward (towards the front panel 11) and enters a closed state.

[0031] Furthermore, when it is desired to automatically open or close only one of the sliding doors, for example, the right sliding door 13, the connecting member 31 and the engaging / disengaging member 33 on the right sliding door 13 side can be brought into an engaged state, and the connecting member 32 and the engaging / disengaging member 34 on the left sliding door 14 side can be brought into a disengaged state, and the same operation as described above can be performed.

[0032] Furthermore, when it is desired to manually open and close each of the sliding doors 13, 14, if it is desired to link the sliding doors 13, 14, the connecting members 31, 32 and the engaging / disengaging members 33, 34 of each of the sliding doors 13, 14 can be engaged, and both the first solenoid valve 80 and the second solenoid valve 82 can be opened to allow air to flow in and out of the cylinder tube 69, allowing the piston rod 68 to move without air resistance within the cylinder tube 69. If it is desired to open or close only one of the sliding doors without linking them, it is only necessary to disengage at least one of the sliding doors 13, 14, for example, the connecting member 31 and the engaging / disengaging member 33, in order to release the linkage between the sliding doors 13, 14, but in this case too, it is necessary to open both the first solenoid valve 80 and the second solenoid valve 82 to allow air to flow in and out of the cylinder tube 69. Here, if the connecting members 31, 32 and the engaging / disengaging members 33, 34 on both sliding doors 13, 14 are disengaged, there is no influence from the air cylinder 63, so there is no need to open the first solenoid valve 80 and the second solenoid valve 82.

[0033] In this embodiment, the air cylinder 63, the pumps 74, 78, and the solenoid valves 80, 82 are arranged in a vertically stacked state and housed within the storage case 5, so that the area occupied by the air cylinder 63, the pumps 74, 78, and the solenoid valves 80, 82 within the storage case 5 can be minimized, making it possible to reduce the size of the entire electronic balance 1.

[0034] Next, a second embodiment of the arrangement of the air cylinder, pump, and solenoid valve of the present invention will be described. 10 , the configurations of the air cylinder, pump, and solenoid valve are the same as those of the air cylinder 63, first pump 74, second pump 78, first solenoid valve 80, and second solenoid valve 82 of the first embodiment described above, respectively. Therefore, the same reference numerals are used to denote corresponding components, and detailed description thereof will be omitted. This embodiment differs from the first embodiment in that the pumps 74, 78, solenoid valves 80, 82, and associated components are disposed within the lower case frame 3, displaced 90 degrees to the left with respect to the air cylinder 63, as viewed from the piston rod 68 side. Therefore, while the forward-side port 91 and the reverse-side port 90 are disposed on the upper side of the cylinder tube 69 in the first embodiment, in this embodiment they are disposed on the lateral side of the cylinder tube 69, opposite the side surface 3 b of the lower case frame 3.

[0035] According to this embodiment, the air cylinder 63, the pumps 74, 78, and the solenoid valves 80, 82 are arranged in parallel and fit within the lower case frame 3, so that the height of the storage case 5 can be made approximately the same height as the lower case frame 3. By minimizing the height of the air cylinder 63, the pumps 74, 78, and the solenoid valves 80, 82 within the storage case 5, the overall height of the electronic balance 1 can be reduced, making it more compact.

[0036] While the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and many modifications are possible. For example, the storage case 5 is not limited to a configuration in which the lower case frame 3 and the upper case frame 4 are combined. Furthermore, the upper panel 10 may be configured to be linked to a linking mechanism so that it opens and closes in conjunction with the left and right sliding doors or separately by the operation of the air cylinder 63. [Explanation of symbols]

[0037] 1. Electronic balance 2 weighing dishes 3 Lower case frame 4 Upper case frame 5 Storage Case 6 Floorboards 7 Weighing Room 8 Windshield 9. Control Panel 10 Top plate 11 Front plate 12 Back plate 13 Right sliding door 14 Left sliding door 16,17 Support case 18,19 Support plate 22,23 Guide rail 25 Protective plate 27 Guide member 28,29 Guide roller 30 fixed frames 31, 32 Connecting member 33, 34 Engagement and disengagement members 60 Connecting plate 63 Air cylinder 68 Piston rod 74 First Pump 78 Second Pump 80 First solenoid valve 82 Second solenoid valve 83,87 Guide plate 84 Rising section 85,86 Guide holes

Claims

1. a storage case for accommodating a weighing mechanism connected to the weighing pan; a windshield that includes a top plate, a front plate, a back plate, and a pair of left and right side plates to cover the weighing dish above the storage case and form a weighing chamber, at least the pair of left and right side plates being sliding doors that can slide in the front-to-rear direction of the storage case; a pair of suspension mechanisms for suspending and supporting the pair of left and right sliding doors so that they can slide independently; a linking mechanism that links the pair of left and right sliding doors so that they can be engaged and disengaged at their lower parts; an air cylinder disposed in the housing case, the air cylinder having a piston rod linked with the linking mechanism to slide the pair of left and right sliding doors via the linking mechanism; An electronic balance comprising:

2. 2. The electronic balance according to claim 1, wherein a pump that serves as a drive source for said air cylinder is disposed inside said storage case.

3. 3. The electronic balance according to claim 2, wherein the air cylinder and the pump are arranged one above the other in the housing case.

4. 3. The electronic balance according to claim 2, wherein the air cylinder and the pump are arranged in parallel inside the housing case.

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