JP5574921B2 - Platform scale - Google Patents

Description

  The present invention relates to a platform scale in which a load detection mechanism is interposed between a pair of upper and lower frames constituting a load support, and in particular, a stopper for protecting the load detection mechanism when an overload is applied to an upper frame. It relates to the platform scale provided.

  This type of platform scale is widely used in distribution centers, fish markets, etc., or when weighing, etc., and various weighing items are mounted.

  For example, as shown in Patent Document 1, a pair of upper and lower sides formed so that a rectangular weighing pan 4 and two steel plates as a support thereof are connected at the center and the overall shape is an “X” shape. Provided on the upper surfaces of the four corners of the frames 1, 2, the load cell (load detection mechanism) 3 for detecting the load interposed between the frames 1, 2, and the upper (dish side) frame 1 There is a configuration including a buffer member 7 serving as a receiving surface of the weighing pan 4 and leveling adjustment legs 5 provided at four corners of the lower (base side) frame 2.

  A stopper 6 protruding upward from the four corners of the base side frame 2 is assembled with a predetermined gap d from the plate side frame 1, and a weighing object heavier than the prescribed weight is placed on the weighing plate 4. When this occurs (when an overload is applied), the upper ends of the four stoppers 6 at the four corners abut against the lower surface of the dish-side skeleton 1 respectively, and the sinking of the dish-side skeleton 1 (the weighing dish 4) is restricted. This limits the lower limit of movement of the load cell 3 and prevents the load cell 3 from receiving an impact (FIG. 6).

  In addition, when the weighing is large, it is suitable to use a prismatic pipe for the frame so that the overall shape is “II” type and the rigidity is increased (Patent Document 1).

Actual climbing 2544234 (paragraph number 0002, FIGS. 2 to 5)

  However, in Patent Document 1, since the stopper 6 and the adjusting leg 5 are not coaxially arranged, the load applied to the stopper 6 is concentrated on a part of the base side frame 2 (reference numeral 2a) at the time of an overload action. There is a possibility that the stopper 6 cannot withstand the stress and is distorted, or the base-side frame 2 is bent and the sinking of the weighing pan 4 cannot be sufficiently prevented, and the load cell 3 is shocked and damaged. In addition, in such a platform scale, the weighing object is not always properly placed on the central portion of the weighing pan 4, and the weighing object is placed on the peripheral portion of the weighing pan 4 and applied with a biased load or concentrated in one place. When a load is applied, an overload acts on the specific stopper 6 and the risk of damaging the load cell 3 increases.

  The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to provide a platform scale that reliably protects a load cell from an impact during an overload action.

  In order to achieve the above object, in the platform scale according to claim 1, the weighing pan having a rectangular shape in plan view and at least the four corners of the back surface of the weighing pan are supported, and the entire shape is substantially the same using a prismatic pipe. A pair of upper and lower frames that support the pair of upper and lower frames formed on, a load detection mechanism interposed between the frames, and fixed to the four corners of the base-side frame disposed on the lower side. Adjusting legs, fixed to the four corners of the dish-side frame arranged on the upper side, projecting downward from the lower surface of the dish-side frame, and regulating the sinking of the weighing pan during an overload action In the platform scale provided with a stopper for restricting the downward movement of the load detection mechanism, the stopper and the adjustment leg are arranged on the same axis.

  (Operation) When the overload is applied, the lower end of the stopper and the upper end of the adjustment leg come into contact with each other over the upper surface of the base-side frame, so the stress applied to the stopper is borne by the adjustment leg (installation surface). There is no excessive stress on the body.

Further, a common mounting hole into which either the mounting portion of the stopper or the mounting portion of the adjusting leg can be inserted is provided on the lower surface of each of the four corners of the upper and lower frames.

  (Operation) Either the stopper mounting part or the adjusting leg mounting part can be inserted into the prismatic pipes arranged at the four corners of the dish side frame to which the stopper is attached and the base side frame to which the adjustment leg is attached. By providing a common mounting hole, the prismatic pipes forming the frame can be used both vertically, so that the frame can be assembled without worrying about whether it is upper or lower.

In addition, a sealing member for closing the opening is inserted into the pipe opening at the four corners of the frame body, the insertion portion of the sealing member communicates with the mounting hole, and the stopper or the adjusting leg mounting portion. Was provided with a fixing hole.

  (Operation) When a stopper or adjustment leg (attachment part) is attached to the attachment hole of the framework with the sealing member inserted into the pipe opening at the four corners of the framework, the attachment part of the stopper or adjustment leg is sealed In order to pass through the fixing hole of the member, the sealing member (insertion portion thereof) is prevented from coming off into the framework (rectangular pipe) simultaneously with the attachment of the stopper or the adjusting leg.

In addition , the upper surface of the dish-side frame is formed to be flush with each other, and the four corners of the upper surface and the frame inside the four corners are substantially equally divided into thin walls that contact the rear surface of the weighing dish. When the weighing pan is bent by a load, the back surface of the weighing pan is supported on the upper surface of the pan-side frame.

  (Operation) Conventionally, as shown in FIG. 6, buffer members 7 having a large thickness and a large receiving surface are generally arranged at four corners of the upper surface of the dish-side frame 1. Since the back (thickness) is high, the weighing pan 4 is supported only at the four corners during weighing, and even if the central portion of the pan is bent, it does not hit the top surface of the pan-side frame 1. In order to withstand, it was necessary to provide a certain thickness (rigidity).

  In the present application, in addition to the conventional four corners, in addition to the conventional four corners, the cushioning member is also provided at a location where the frame body is substantially equally divided to ensure the anti-slip effect, and the thickness is made thinner (lower) than the conventional one. As a result, as soon as the weighing pan bends during weighing, the back of the weighing pan is carried on the upper surface of the plate-side skeleton that is flush with the plate, so that the stress on the weighing pan is well distributed throughout the pan-side skeleton. The

  As described above, according to the first aspect of the invention, since the dispersion of the stress applied to the stopper is good and the sinking of the weighing pan is appropriately regulated and the downward movement of the load detection mechanism is restricted, the load detection mechanism Can be reliably protected from impact.

In addition , since the prismatic pipes that form the frame can be used both at the top and bottom, the assembly work of the frame is facilitated and is optimal for mass production, so that a significant cost reduction can be realized.

Moreover , the sealing member for preventing the entry of dust and insects into the prismatic pipe can be surely prevented from coming off in the stopper or adjusting leg attaching process.

According to the second aspect of the invention, since the stress at the time of weighing is borne not only by the weighing pan but also by the side frame of the pan, the plate thickness of the weighing pan can be reduced accordingly (the rigidity of the weighing pan can be reduced). Therefore, the weighing pan becomes lighter. In addition, since the amount of deflection of the weighing pan is small, it is possible to avoid the weighing pan from sagging.

  In addition, since the plate | board height of a platform scale becomes low by that much as the plate | board thickness of a weighing pan and the thickness of a buffer member are thinner than before, a platform scale becomes compact and loading work becomes easy.

  Next, embodiments of the present invention will be described based on examples.

  1 to 5 show an embodiment of the present invention, FIG. 1 is an exploded perspective view of a platform scale according to an embodiment of the present invention, FIG. 2 is an upper perspective view of a load measuring unit of the platform scale, and FIG. 4 is a sectional view taken along line III-III shown in FIG. 2, and FIG. 4 is an enlarged longitudinal sectional view of a stopper and an adjustment leg attaching portion as main parts (cross section taken along line IV-IV shown in FIG. 2). FIG. 5 is a perspective view of the sealing member.

  In these figures, a platform scale 10 is connected to a platform scale body (load measurement unit) 11 having a rectangular shape in plan view, a column 12 extending upward from the side of the load measurement unit 11, and an upper end of the column 12. And a digital display 13 for digitally displaying the calculation result (measurement value) of the load signal detected by the.

  The load measuring unit 11 is interposed between the upper and lower frames 40a and 40b, the height adjusting legs 14 attached to the four corners of the lower frame 40b and maintaining the horizontal state, and the frames 40a and 40b. The load cell 20 which is a loaded load detection mechanism, a weighing pan 15 having a rectangular shape in plan view placed over the upper frame 40a, and stoppers 30 provided on the lower surfaces of the four corners of the upper frame 40a. .

  The adjusting leg 14 is formed by integrally molding a resin leg on the head of a hexagon bolt 60 having a male screw portion 14b (attachment portion), and the stopper 30 is configured by the same hexagon bolt 60 as the adjusting leg 14. Yes.

  The upper and lower frames 40a and 40b are composed of a vertical pinion portion 41 in which two flat iron prismatic pipes of the same length are arranged in parallel, and the vertical pinion portion 41 using the same prismatic pipe as the vertical pinion portion 41. It is mainly composed of two horizontal hook portions 42 arranged in parallel so as to connect the vertical hook portions 41 and 41 at equal positions. The vertical hook portion 41 and the horizontal hook portion 42 are directly attached and integrated by welding. In addition, both the frame bodies 40a and 40b are formed in a Roman numeral II type in plan view.

  Since the vertical hook portion 41 and the horizontal hook portion 42 are made of the same member, the frames 40a and 40b are uniformly rigid and lightweight as a whole, and the upper surfaces 44a and 44b of the frames 40a and 40b are flush with each other. Is formed.

  Mounting holes 43a and 43b into which the adjusting legs 14 or the male threaded portions 14b of the stopper 30 are inserted are provided on the lower surface side of the end portions of the vertical hook portions 41 of the frame bodies 40a and 40b (four corners of the frame bodies 40a and 40b). ing. A nut 46 into which the adjustment leg 14 or the male thread 14b of the stopper 30 is screwed is welded to the opening 45 of the mounting holes 43a and 43b at a position where the nut 46 communicates with the mounting holes 43a and 43b.

  That is, either the adjustment leg 14 or the stopper 30 can be attached to the attachment holes 43a, 43b (nuts 46) of the upper and lower frames 40a, 40b.

  In the assembling process of the frames 40a and 40b, the upper and lower frames 40a and 40b are formed by the same members (the vertical hook portion 41 and the horizontal hook portion 42), and the mounting positions of the mounting holes 43a and 43b and the nut 46 are also set. Since the upper and lower sides are the same, the frame (vertical can 41 and horizontal can 42) can be assembled without worrying about whether the upper or lower is separate, and the assembly of the frame is easy.

  Further, since the vertical hook portion 41, the horizontal hook portion 42 and the nut are the upper and lower members, the upper and lower parts can be used together, and the adjustment leg 14 and the stopper 30 parts (hexagon bolt 60) are also common as described above. Since the embodiment is designed optimally for mass production, significant cost reduction is realized.

  Next, a fixing plate 50b and a support plate 51b on which a load cell 20 (the lower surface thereof) described later is placed are arranged on the upper side of the base frame 40b arranged on the lower side when the platform balance 10 is assembled. A fixing plate 50a to which the upper surface of the load cell 20 is fixed is integrated with the dish-side frame 40a by welding so as to connect the respective side hooks 42, and a pair of upper and lower base-side frames 40b and a dish-side frame are assembled. It becomes the body 40a.

  The load cell 20 is configured by attaching a strain gauge to a strain-generating portion 24 of a strain-generating body 21 having a rectangular parallelepiped outer shape, and an upper surface on one end thereof is a load application portion 22, and the other end The part-side lower surface is a fixed part 23. At the time of measurement, the strain gauge detects the strain amount of the strain generating portion 24 with respect to the load acting on the load applying portion 22, and the measured value is electrically measured.

  Further, a central stopper 26 is provided on the lower surface side of the load application portion 22 to prevent the strain generating portion 24 from being excessively deformed during an overload action and to prevent the load cell 20 from being damaged.

  In the case of a platform scale having the same area as the upper surface of the load cell 20 and the weighing pan 15, it is possible to prevent the load cell 20 from being damaged only by the central stopper 26, but the weighing pan with respect to the upper surface of the load cell 20 as in this embodiment. In the type of scale with a large area 15, the strain amount of the strain generating portion 24 is particularly large when an overload is applied to the peripheral portion of the weighing pan 15. In this embodiment, therefore, the stoppers 30 are provided at the four corners of the skeletons 40a and 40b to reduce the distortion of the strain generating portion 24, and the load cell 20 is double protected.

  In the load cell 20, the lower surface fixing portion 23 is bolted to four fixing plates 50b of the base side frame 40b, and the load applying portion 22 on the upper surface is bolted to four fixing plates 50a of the dish side frame 40a. , Between the skeletons 40a and 40b.

  In this embodiment, the parts are shared by using the same hexagon bolt 60 as the adjusting leg 14 and the stopper 30 for the bolt.

  And the lower surface side of the load application part 22 part is supported also by the support plate 51b of the base side frame 40b, and the center stopper 26 protrudes downward from the hole provided in the support plate 51b.

  A rubber sealing member 70 that closes the opening 45 is inserted into the opening 45 at the end of each of the frame bodies 40a and 40b made of a prismatic pipe in order to prevent dust and insects from entering the prism pipe.

  The sealing member 70 includes an insertion portion 71 that is inserted into the prismatic pipe and a blindfold portion 72 that covers the opening 45.

  At the distal end of the insertion portion 71, a cylindrical fixing hole 73 that matches the hole diameter of the mounting holes 43a and 43b of the skeletons 40a and 40b extends in a plate shape on the base end side in a direction perpendicular to the insertion direction. The rib portions 74 are provided at three left and right equal intervals, and the base end portion of the insertion portion 71 is a flat-plate-like blindfold portion 72 that is slightly larger than the opening portion 45.

  By providing the rib portion 74, the strength of the insertion portion 71 is increased, and the dimensional accuracy of the prismatic pipe and the sealing member 70 is relaxed. Further, since the end of the rib portion 74 is formed in a tapered shape that becomes narrower as it goes in the insertion direction, the rib portion 74 is flexible and can be easily inserted into the prismatic pipe, but in the opposite direction. The shape is hard to come off.

  And if the sealing member 70 (insertion part 71) is inserted in the opening part 45 of the frame 40a, 40b and the stopper 30 or the adjustment leg 14 (the external thread part 14b) is attached to the attachment holes 43a, 43b, the insertion part 71 will be described. The stopper 30 or the adjusting leg 14 (the male threaded portion 14b) is also inserted into the fixing hole 73, so that the insertion portion 71 is prevented from coming off in the frame bodies 40a and 40b (inside the prismatic pipe), and the opening 45 is a blind portion. 72 is completely sealed.

  On the upper surface 44a of the dish-side frame 40a formed flush with each other, circular cushioning rubber 80, which is a thin and small cushioning member that comes into contact with the back surface of the weighing dish 15, is provided at the four corners of the upper surface 44a and inside the four corners. Bonded and fixed. Specifically, four places on the stopper 30 arrangement place of the vertical hook part 41 and two symmetrically spaced two places on the fixing plate 50a, 50b and support plate 51b near the welded part of the horizontal hook part 42, a total of 8 places. It is provided in the place. In addition, you may use well-known things, such as a urethane resin, as a buffer member.

  Conventionally, as shown in FIG. 6, the buffer member 7 having a large thickness and a large receiving surface is generally arranged at the four corners of the upper surface of the dish-side frame 1. ) Is high, the weighing pan 4 is supported only at the four corners during weighing, and even if the central part is bent, it does not hit the upper surface of the pan-side frame 1, so that the weighing pan 4 itself can withstand concentrated loads. It was necessary to provide thickness (rigidity).

  In the present embodiment, the buffer rubber 80 is provided inside the four corners in addition to the conventional four corners, and the number of contact points between the weighing pan 15 and the pan-side frame 40a is increased from four to eight, so that the weighing pan 15 Is prevented from slipping and the stability of the weighing pan 15 is improved, so that the receiving surface of the buffer rubber 80 is smaller than the conventional one. Then, as soon as the weighing dish 15 is bent by the load, the buffer rubber 80 is very thin so that the back surface of the weighing dish 15 comes into contact with the upper surface 43a of the dish frame 40a and is supported by the dish frame 40a. The thing was adopted.

  Specifically, a conventional rubber having a diameter of 5 cm and a thickness of 10 mm was used, and a rubber having a diameter of 1 cm and a thickness of 2 mm was used. This is because the smaller the difference between the dish-side frame and the buffer member, the more advantageous the deflection of the weighing dish.

  Above the dish-side frame 40a, a stainless steel weighing dish 15 having a rectangular shape in plan view is placed so as to cover the frame 40a. The lower end portion of the weighing pan 15 is safe because it is folded inward by hemming so that no sharp portion appears outside the weighing pan 15.

  Further, as described above, since the thickness of the buffer rubber 80 is thin, as soon as the weighing pan 15 bends due to the load, the back surface of the weighing pan 15 comes into contact with the upper surface 43a of the pan-side frame 40a and is supported. 15, the plate-side frame 40 a is also configured to bear the load, so that the plate thickness of the weighing pan 15 can be reduced by that amount (the rigidity of the weighing pan is lowered), and the weighing pan 15 can be made to that extent. Is also lighter.

  Specifically, since it is now possible to use a 0.8 mm thick steel plate that used a 1.5 mm thick stainless steel plate, it is approximately 45% lighter than before. Was achieved.

  In addition, since the amount of deflection of the weighing pan 15 carried by the pan-side frame 40a is small, the weighing pan 15 can be prevented from sag.

  Finally, the load measuring unit 11 of the platform scale 10 is assembled by screwing the adjusting leg 14 (the male screw portion 14b) into the nut 46 with the sealing members 70 inserted into the four corners of the base side frame 40b. The sealing member 70 and the adjusting leg 14 are attached, the load cell 20 (fixing part 23) is bolted on the fixing plate 50b, and the washer 61 is inserted in the state where the sealing member 70 is inserted into the four corners of the dish-side frame 40a. The stopper 30 (the male screw portion 14b) is screwed to the nut 46 to attach the sealing member 70 and the stopper 30, and the countersunk frame 40a is bolted onto the load cell 20 (load applying portion 22). The weighing pan 15 is placed over the pan-side frame 40a to complete the load measuring unit 11.

  The sealing member 70 inserted into the opening 45 of the dish-side frame 40a and the base-side frame 40b is also attached to the fixing hole 73 of the insertion portion 71 at the same time as the stopper 30 or the adjustment leg 14 is attached. The leg 14 is inserted, and the insertion portion 71 is prevented from being detached from the frame bodies 40a and 40b (inside the prismatic pipe), and the opening 45 is completely sealed by the blindfold 72. Therefore, since the sealing member 70 is surely prevented from being detached in the assembly process of the platform balance 10, the sealing member 70 is not detached during the use process of the platform balance 10, and the opening 45 is not exposed, and the entry of dust and insects is prevented. Is prevented.

  Further, the stopper 30 protrudes downward from the lower surface of the dish-side frame 40a, and the lower end 31 of the stopper 30 and the upper surface 43b of the base-side frame 40b have a predetermined gap d from the viewpoint of restricting the downward movement of the load cell 20. It becomes the form.

  Further, since the thickness of the buffer rubber 80 and the plate thickness of the weighing pan 15 are thin, the mounting height H (FIG. 2) of the platform scale 10 is about 30% lower than the conventional one. For this reason, the platform scale is made more compact, and the loading operation is easy for the user.

  And the stopper 30 and the adjustment leg 14 which were attached to each four corners of a pair of upper and lower countersunk side frame 40a and base side frame 40b of the same shape are arranged on the same axis.

  At the time of weighing, the measurement value is electrically measured by detecting the strain amount of the strain generating portion 24 that is distorted with respect to the load acting on the load applying portion 22 by the strain gauge of the load cell 20 due to the load applied to the weighing pan 15. The measured value is displayed on the digital display 13.

  Further, as soon as the weighing pan 15 bends, the back surface of the weighing pan 15 is held in contact with the upper surface 43a of the pan-side frame 40a, and the stress applied to the weighing pan 15 is a vertical canopy 41 and the pan-side frame 40a. It is well dispersed in the side lip 42.

  When the overload is applied, the lower end portion 31 of the stopper 30 and the upper end portion 14a of the adjustment leg 14 come into contact with each other over the upper surface 43b of the base side frame 40b, so that the stress applied to the stopper 30 is adjusted by the adjustment leg 14 (installation surface). Therefore, an excessive stress does not act on the stopper 30 and an excessive bending stress does not act on the base side frame 40b.

  Therefore, since the stress dispersion is good, the sinking of the weighing pan 15 is surely regulated and the lower limit of movement of the load cell 20 is appropriately restricted, so that the load cell 20 can be reliably protected from impact.

  In addition, by changing the size and thickness of the prismatic pipe in the present embodiment, it is possible to obtain a framework having appropriate rigidity for a desired weighing. In other words, by simply selecting the size of the prismatic pipe in accordance with the weighing size, it is possible to easily design a skeleton body corresponding to both a large weighing platform and a small weighing platform.

  In addition, the shape of the upper and lower frames is substantially the same and is very simple, and the number of components is smaller than before because the components of the frame are shared. Furthermore, since the load measuring unit 11 is compact, packaging is easy.

The disassembled perspective view of the platform scale which concerns on the Example of this invention. The upper perspective view of the load measurement part of the platform scale. The longitudinal cross-sectional view of a load measurement part. The enlarged longitudinal cross-sectional view of the stopper which is the principal part, and an adjustment leg attachment part. The perspective view of a sealing member. The schematic front view of the conventional platform scale.

10 platform scale 11 load measuring unit 12 support column 13 digital display 14 adjusting leg 14a adjusting leg upper end part 14b male screw part 15 as mounting part weighing pan 20 load cell 30 stopper 31 stopper lower end part 40a countersunk side frame (upper frame)
40b Base side frame (lower frame)
43a, 43b Frame assembly mounting holes 44a, 44b Frame top surface 45 Frame opening 60 Hexagon bolt 70 Sealing member 71 Sealing member insertion part 72 Sealing member blinding part 73 Sealing member fixing hole 80 Buffer rubber

Claims (2)

A rectangular weighing pan in plan view;
A pair of upper and lower frames that support at least the four corners of the back surface of the weighing pan and are formed to have substantially the same shape as a whole using a prismatic pipe,
A load detection mechanism interposed between the frames;
Adjustment legs fixed to the four corners of the base side frame disposed on the lower side,
It is fixed to the four corners of the dish-side skeleton arranged on the upper side, protrudes downward from the lower surface of the dish-side skeleton, and regulates the sinking of the weighing pan during an overload action, thereby lowering the load detection mechanism. In a platform scale provided with a stopper for limiting movement,
The stopper and the adjustment leg are arranged on the same axis ,
A common mounting hole into which either the mounting portion of the stopper or the mounting portion of the adjustment leg can be inserted is provided on the lower surface of each of the four corners of the upper and lower frames.
A sealing member that closes the opening is inserted into the pipe opening at the four corners of the frame body. The insertion portion of the sealing member communicates with the mounting hole, and the stopper or the mounting portion of the adjustment leg is provided. A platform scale provided with a fixing hole to be inserted .   The upper surface of the dish-side frame is formed to be flush with each other, and the four corners of the upper surface and the portion inside the four corners that are substantially equally divided are thin-walled parts that contact the back surface of the weighing dish. 2. The platform scale according to claim 1, wherein a buffer member is provided, and when the weighing dish is bent by a load, the back surface of the weighing dish is also supported on the upper surface of the dish-side frame.

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