JP2005140625A - Balance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sanitary balance while having waterproof/dustproof functions. <P>SOLUTION: In the balance 1 composed of a measuring dish 10 and a balance body 11, the balance body 11 comprises: a load detection mechanism 5 connected to the lower portion of the measuring dish 10; a computing means 6b for computing a load value, based on the output value of the load detection mechanism 5; a display means 6c for displaying a load value computed by the computing means 6b for visually recognizing from the surface; a lower case 2 for supporting an operation key 6a for performing each kind of operation from the surface; an upper case 3 that is installed opposite to the lower case 2 and prevents a disturbance material, such as water and dust/dirt, from entering by sealing components supported by the lower case 2; and a cover 4 made of metal for covering the upper case 3. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a scale, and more particularly, to a hygienic scale having a waterproof and dustproof function.

  Conventionally, balances, load scales, moisture scales, and other scales that have a load detection mechanism such as a load cell are used in order to prevent disturbance materials such as water and dust from entering the load detection mechanism and the electronic circuit board. The bottom case and the outer cover are closely fitted, and processing such as providing an upright part to prevent disturbance material intrusion between the outer cover and the weighing pan (for example, patents) Reference 1 and Patent Reference 2).

Japanese Patent Laid-Open No. 2003-232672 No. 7-4518

  However, the outer cover of the scale configured as described above is generally made of resin because it requires complicated processing such as a fitting structure and a bending curve. However, a scale having an outer cover made of resin is unhygienic because odors and dirt are easily infiltrated and difficult to clean, and cannot be used for measuring foods such as meat and fish and agricultural products. It was.

The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a hygienic scale that can prevent the intrusion of a disturbance material.

  In order to achieve the above object, a scale according to the present invention is a scale composed of a weighing pan and a balance body, wherein the scale body is connected to a lower portion of the weighing pan, and the load detection mechanism. Calculation means for calculating the load value based on the output value of the mechanism, display means for displaying the load value calculated by the calculation means and making it visible from the surface, and operation keys capable of performing various operations from the surface And a lower case that supports the load detection mechanism, the calculation means, the display means, and the operation key, and is installed to face the lower case, and the load detection mechanism, the calculation means, the display means, and the The operation key is hermetically sealed to have an upper case that prevents intrusion of disturbance materials such as water and dust, and a metal cover that covers the upper case or a resin cover whose surface is plated with metal.

  According to the scale configured as described above, the upper case seals the parts such as the display means supported by the lower case and plays a role of preventing disturbance material intrusion, so that it is not necessary to take waterproof and dustproof for each part. Furthermore, since the cover is made of metal or the surface is plated, it is easy to remove and wash, etc. Also, it is difficult for odors and dirt to adhere, so it can be used for weighing food and agricultural products and is hygienic. .

  In addition, a concave portion is formed in the outer peripheral frame of the upper case, and the concave portion is fitted with packing, and the outer peripheral frame of the upper case is overlapped with the outer peripheral frame of the lower case. Good.

  According to this configuration, since the packing is used, a complicated sealing structure or the like is not required, and the parts supported by the lower case are sealed easily and reliably.

  The cover may be made of stainless steel having high rigidity and corrosion resistance.

  According to this configuration, since the appearance is made of stainless steel, there is a sense of quality and cleanliness, and it is sturdy and can withstand abuse.

  The upper case may be formed of a resin material, a portion corresponding to the upper portion of the display means may be formed transparently, and the cover may have an opening corresponding to the upper portion of the display means. .

Since the cover is not provided with a waterproof and dustproof function, the degree of freedom in designing the cover is increased, and an opening can be provided freely as in this configuration. In addition, since the upper case is covered with a cover, it may be made of an inexpensive and easy-to-mold resin, and the transparent part of the upper case directly serves to protect the liquid crystal screen of the display means. There is no need to provide it, and the display on the liquid crystal screen can be transmitted to the outside through the upper case.

  According to the scale of the present invention, the upper case seals the parts such as the display means supported by the lower case and plays the role of preventing disturbance material intrusion. Therefore, it is not necessary to take waterproof and dustproof for each part. Furthermore, since the cover is made of metal or the surface is plated, it is easy to remove and wash, etc. Also, it is difficult for odors and dirt to adhere, so it can be used for weighing food and agricultural products and is hygienic. .

  In particular, if the cover is made of stainless steel having high rigidity and corrosion resistance, it has a high-class feeling and a clean feeling, and is sturdy and can withstand abuse.

  Further, the cover is not provided with a waterproof and dustproof function, and an opening for allowing the display on the liquid crystal screen of the display means to transmit light to the outside can be provided. In addition, since the upper case is covered with a cover, it may be made of an inexpensive and easy-to-mold resin, and the transparent part of the upper case directly plays a role of protecting the liquid crystal screen of the display means. There is no need to provide it.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. 1 to 4 show an embodiment of a scale according to the present invention. FIG. 1 is an external perspective view of the scale 1, FIG. 2 is an exploded perspective view of the scale 1, and FIG. FIG. 4 is a partial longitudinal sectional view of the balance 1.

  As shown in FIG. 1, the balance 1 according to the present embodiment includes a weighing pan 10 and a balance body 11. Further, as shown in FIG. 2, the weighing pan 10 is composed of a platform 10a and an upper plate 10b that covers the platform 10a from above, and an object to be weighed is placed on the upper surface of the upper plate 10b.

  The platform 10a is generally formed of a resin material and has a through hole 10d of a screw 10c at the center.

  The upper plate 10b is molded from a metal material such as stainless steel or a resin material whose surface is subjected to metal plating in consideration of hygiene when placing food or agricultural products directly and ease of maintenance such as washing. It is desirable.

  As shown in FIG. 2, the scale body 11 mainly includes a lower case 2, an upper case 3, and a cover 4. The lower case 2 is made of synthetic resin in this embodiment, and supports and accommodates the load cell 5 and the electronic circuit board 6.

  An example of the load detection mechanism is the load cell 5 of the present embodiment. The load cell 5 is configured by affixing a strain detecting element (not shown) such as a strain gauge to a strain generating body, and detects tensile strain and compression strain generated when the weight of an object to be measured is applied to the strain generating body. Detects electrically. The load detection mechanism may be an existing load sensor such as a capacitance type sensor in addition to the load cell 5 in the present embodiment, and various selections are possible depending on the weighing, the object to be weighed, the application, and the like. .

  The load cell 5 is connected and integrated with a platform 10a of the weighing pan 10 through a vertically movable tray bearing 7. In the present embodiment, the countersunk bearing 7 has a substantially U-shaped base portion 7a fixed to the upper portion of the load cell 5, a screw hole 7b in the central portion of the upper surface, and an annular groove 7d in the middle portion in the vertical direction. This is a resin part that is provided with a cylindrical top portion 7c and is molded by injection molding or the like. The platform 10a of the weighing pan 10 is fixed to the upper portion of the pan bearing 7 by passing the screw 10c through the screw hole 7b and the through hole 10d of the platform 10a. The shape of the pan bearing 7 is not limited to the shape of the above embodiment as long as the load cell 5 and the weighing pan 10 can be connected.

  In this embodiment, the electronic circuit board 6 is constituted by a single board having a space for mounting all of the operation keys 6a, the calculation means 6b, and the display means 6c, and a power supply chamber for supplying power to these electronic circuits. It is raised by a height corresponding to the height (not shown), and is fixed to a position spaced upward from the bottom surface of the lower case 2 via a substrate fixing spacer 2a having a height corresponding to the height of the bottom. Dry batteries are accommodated in the power supply chamber, and the batteries are replaced from the back side by opening and closing a cover of a battery case (not shown) provided on the back side of the lower case 2.

  In order to prevent disturbance materials such as water and dust from entering the lower case from the power supply chamber directly in contact with the ground, the lower case support legs 2b are used as in this embodiment. May be integrally formed on the back surface of the lower case 2, and the bottom surface of the lower case 2 may be raised. Further, the electronic circuit board 6 may be composed of a plurality of boards instead of a single board.

  The load value of the object to be weighed placed on the weighing pan 10 is detected from the load cell 5 via the pan bearing 7 as a load receiver after detecting the operation of the operation key 6a such as a power switch or a weighing start key operable from the surface. After being processed by the calculation means 6b configured by a bridge circuit or the like that is detected as an output and connected to the strain detection element, it is digitally displayed on the liquid crystal display screen of the display means 6c so as to be visible from the surface. .

  The upper case 3 is made of a synthetic resin in the present embodiment, like the lower case 2, but is installed facing the lower case 2 and seals the load cell 5 and the mounted components of the electronic circuit board 6 supported by the lower case 2. Thus, the lower case 2 is formed in a substantially planar dome shape that prevents the entry of disturbance materials such as water and dust. Since the upper case 3 has such a substantially planar shape, the scale body 11 can be miniaturized.

  In this embodiment, a recess (not shown) is provided at the bottom of the outer peripheral frame 3a of the upper case 3, and a packing 30 is fitted in the recess in a close contact state. As shown in FIG. 3, the load cell 5 and the electronic circuit board 6 fixed to the lower case 2 are easily sealed by overlapping the outer peripheral frame 3a of the upper case 3 and the outer peripheral frame 2c of the lower case 2. The Since the lower case 2 and the upper case 3 are made of synthetic resin, the recesses and the like can be easily formed and the cost is low.

  Conventionally, there is no upper case 3 that integrally covers and seals the load cell 5 and the electronic circuit board 6, and the position is determined by the calculation means 6b that is easily disposed in the vicinity of the load cell 5 and the restrictions on the external design. Since the display means 6c which is easy to be mounted is separately mounted on a separate substrate, a structure for individually sealing the calculation means 6b and the display means 6c is necessary for waterproof and dustproof. However, since the load cell 5 and the electronic circuit board 6 are integrally covered and sealed by the upper case 3 as in this embodiment, there is no need to separate the sealed structure as in the prior art, and the assembly work of the scale Is easy to do.

  In the present embodiment, the lower case 2 and the upper case 3 are fixed by four screws 3b as shown in FIG. The upper case 3 is provided with four mounting holes 3c so as to be substantially equidistant, and the lower case 2 is provided with a cylindrical spacer 2d having a screw hole provided concentrically with the mounting hole 3c. ing. After the lower case 2 and the upper case 3 are overlapped via the packing 30, the screw 3b is inserted into the mounting hole 3c and the screw hole of the cylindrical spacer 2d from above, so that the head of the screw 3b is attached to the mounting hole 3c. The lower case 2 and the upper case 3 are fixed and integrated with each other on an inner locking plane (not shown).

  The cover 4 is made of a metal material that covers the upper case 3 or a resin material whose surface is plated with metal. As shown in FIG. 2, the upper case 3 can be overlapped with the upper case 3. The upper case 3 is formed in a substantially flat dome shape that integrally covers the upper case 3 from above with substantially the same shape as the above.

  The role of the cover 4 in this embodiment can be used to measure foodstuffs and agricultural products such as meat and fish, and it is difficult for odors and dirt due to these foodstuffs and agricultural products to adhere to them. It is to use a scale, to avoid exposure of the upper case 3 and to maintain aesthetics, and to simply protect the lower case 2 and the load cell 5 and the electronic circuit board 6 supported by the upper case 3.

  In this embodiment, as shown in FIG. 2, the upper case 3 is formed with insertion recesses 3j for the four screws 4a so as to have substantially equal intervals. A columnar metal spacer (not shown) having a threaded hole is press-fitted into the recess 3j, and the columnar metal spacer closes the recess 3j from above. The cover 4 is fixed to the upper case 3 by inserting a screw 4a from a screw hole 4b provided concentrically with the threaded hole. The recess 3j has a structure that does not penetrate the upper case 3 and is integrally formed with the upper case 3. Therefore, there is no possibility that a disturbance material enters the lower case 2 from the screw hole 4b of the cover 4.

  Thus, it is not necessary to provide the cover 4 with a special mechanism for waterproofing, dustproofing, retaining prevention, sealing, etc., and it is fixed to the lower case 2 and / or the upper case 3 by simple fixing means such as screws. It is only necessary to cover the upper case 3 from above, and in the scale of the present invention, the degree of freedom in designing the cover 4 is increased. And the sanitary balance which can replace | exchange the cover 4 easily by a user and can also clean the cover 4 by washing | cleaning etc. is implement | achieved.

  In addition, in the conventional scale, the cover exposed to the outside itself functions for waterproof and dustproofing. If the cover is made substantially flat, water will accumulate on the cover and disturbance materials will easily enter, so the waterproof and dustproof function is satisfied. However, in the scale of the present invention, the cover 4 does not have to play a waterproof and dustproof role and can be made substantially flat, so that the scale body 11 can be made smaller and more compact. It is done.

  Furthermore, in the present embodiment, the outer peripheral edge of the cover 4 stands up more than the outer peripheral edge of the upper case 3, and covers the entire upper case 3 from above. Thereby, the standing part of the outer peripheral edge of the cover 4 is fixed in contact with the outer peripheral frame 2c of the lower case 2 to protect the upper case 3 and the lower case 2 support (load cell 5 and electronic circuit board 6) from impact. I can do it.

  The cover 4 of the present embodiment is made of water-resistant stainless steel, and can be easily mass-produced by sheet metal press molding including a cutting process. By adopting stainless steel, the balance is excellent in water resistance, rust resistance, heat resistance, durability, corrosion resistance, chemical resistance, and the like. In addition, the metallic luster unique to stainless steel provides a calm texture, luxury and cleanliness that cannot be obtained with conventional resin covers. Furthermore, since the cover 4 of this embodiment has high rigidity, it is strong and can withstand abuse.

  The cover 4 may be made of stainless steel, aluminum die-casting or other metal material having high rigidity and corrosion resistance, or a resin material obtained by processing these metal materials on the surface. The upper plate 10b is preferably made of the same material.

  On the other hand, the upper case 3 is covered with the cover 4 and cannot be visually recognized from the outside. Therefore, the upper case 3 only needs to be designed specifically to prevent the disturbance material from entering the lower case 2. It is easy to process and form a sealed structure with packing 30 or the like interposed therebetween, and it is possible to select an inexpensive resin.

  The upper case 3 of the present embodiment has a circular opening 3 d that penetrates the top 7 c of the dish bearing 7. The opening 3d is opened larger than the outer diameter of the top 7c so that the plate bearing 7 can be moved up and down. Therefore, there is a possibility that a disturbance material may enter the lower case 2 from the gap between the dish bearing 7 and the opening 3 d, and the meaning of sealing the lower case 2 with the packing 30 is lost. Therefore, a diaphragm 8 that covers the opening 3d is attached to the upper case 3 of this embodiment together with the O-ring 9 so that the upper case 3 can maintain the hermeticity of the lower case 2.

  The diaphragm 8 is made of a synthetic resin having elasticity and waterproofness such as soft rubber. As shown in detail in the longitudinal sectional view of FIG. 4 and the perspective view of the diaphragm 8 of FIG. 5, the through hole 8a, the bellows 8b, and the base 8c.

  The through-hole 8a is provided in the center part of the diaphragm 8, and penetrates the plate bearing 7 in a close contact state. In the present embodiment, the outer peripheral edge of the through hole 8a is an upright portion having substantially the same width as the longitudinal width A of the annular groove 7d formed on the outer periphery of the plate bearing 7, as shown in FIG. Yes. The upright portion is fitted in the annular concave groove 7d in a close contact state, and prevents the disturbance material from entering the inside of the lower case 2 through the gap between the through hole 8a and the dish bearing 7. Since the standing portion of the through hole 8a is securely fitted and fixed in the annular concave groove 7d, the diaphragm 8 is prevented from coming off and there is no possibility that a disturbance material enters. The width (height) of the standing portion of the through hole 8a may be equal to or smaller than the width A of the annular groove 7d.

  The bellows 8b is provided on the outer periphery of the through hole 8a, and is configured to be flexible and extendable so as not to exert a load on the vertical movement of the dish bearing 7.

  The base portion 8c is provided on the outer periphery of the bellows 8b, has an annular protrusion 8d on the lower surface, and is fitted in an annular groove 3e formed in the upper case 3 in a close contact state and attached to the upper case 3. It has become. The annular groove 3e also plays a role of positioning when the diaphragm 8 is fitted to the upper case 3.

  Furthermore, the base portion 8c of the present embodiment has an annular protrusion 8e on the upper surface similar to the lower surface. When the upper case 3 and the cover 4 are fixed from above by the screws 4a, the protrusion 8e comes into contact with the cover 4 and elastically engages with the protrusion 8e, and the base 8c is crimped to the upper case 3 and the upper case 3 And the cover 4 are prevented from entering the gap.

  That is, the diaphragm 8 of the present embodiment is easily attached and fixed to the upper case 3 by close contact or pressure bonding without using screws or attached members, so that the assembling work of the scale is simplified. In addition, the diaphragm 8 does not require a screw for mounting and covers the opening 3d of the upper case 3 to prevent the intrusion of the disturbance material into the lower case 2. There is no risk of rusting.

  Further, as shown in FIG. 5, the diaphragm 8 of this embodiment includes four projecting pieces 8f extending from the base 8c, and the four projecting pieces 8f are arranged at equal intervals. These protrusions 8f are also fitted in close contact with the recessed grooves 3f formed in the upper case 3, as shown in FIG. Thereby, positioning and attachment of the diaphragm 8 are performed more smoothly.

  Further, as shown in FIGS. 4 and 5, a convex portion 8g formed integrally with the projecting piece 8f or bonded or pressure-bonded after forming the diaphragm 8 is formed on the lower surface of the terminal portion of the projecting piece 8f. Yes. Since the convex portion 8g is also fitted in the concave groove 3g formed in the upper case 3 in a close contact state, the diaphragm 8 is securely attached.

  In the present embodiment, the mounting hole 3c of the screw 3b for fixing the lower case 2 and the upper case 3 as described above is formed in the concave groove 3g fitted into the convex portion 8g, as shown in FIG. The convex portion 8g is formed in a cylindrical shape having an open bottom surface and capable of accommodating and closing the head of the screw 3b from above. That is, the convex portion 8g of the present embodiment closes the screw 3b and the mounting hole 3c from above, so that not only the function of fixing the upper case 3 and the diaphragm 8 tightly but also from the mounting hole 3c to the inside of the lower case 2 is achieved. It also has a function to prevent disturbance material intrusion, which makes it possible to achieve waterproofing and dustproofing in a complete sense. Moreover, since the head of the screw 3b is covered with the convex portion 8g, the screw 3b is not likely to rust, and the quality and performance of the scale are maintained for a long time.

  A cylindrical boss 3h is integrally formed with the upper case 3 below the periphery of the concave groove 3g of the present embodiment, as shown in FIG. The cylindrical spacer 2d of the lower case 2 is formed so as to be positioned when the lower case 2 and the upper case 3 are fixed by being fitted and locked in the cylinder of the boss 3h.

  Further, as shown in FIGS. 2 and 3, the upper case 3 has a waterproof and dustproof and air-permeable member 31 for maintaining a sealed state of the load cell 5 and the electronic circuit board 6 and eliminating a difference in internal and external pressures of the load cell 5. Is provided so as to cover the hole 3 i provided on the upper surface of the upper case 3.

The waterproof and dustproof breathable member 31 of this embodiment is Microtex (registered trademark) manufactured by Nitto Denko. Microtex is a porous film of tetrafluoroethylene resin having hundreds of millions of fine pores per 1 cm ² , and has waterproofness, dustproofness and air permeability.

  That is, by providing such a waterproof and dustproof breathable member 31 so as to cover the hole 3 i of the upper case 3, the internal pressure of the space sealed by the lower case 2 and the upper case 3 is connected to the weighing pan 10. Even if the plate bearing 7 is compressed as it moves up and down, it quickly diverges to the outside through the waterproof and dustproof air-permeable member 31. Therefore, the pressure inside and outside the sealed load cell 5 is always the same, and the measurement due to the internal and external pressure imbalance The error can be eliminated. In addition, since the hole 3i is covered with the waterproof and dustproof and breathable member 31, the intrusion of disturbance material into the lower case 2 is prevented, and complete waterproofing and dustproofing are achieved. In addition, since it is not necessary to provide a dedicated ventilation member or the like for preventing the intrusion of the disturbance material as in the prior art, the scale body 11 can be downsized.

  In this embodiment, in order to minimize the weighing error of the load cell 5, a circular hole 3i having a diameter of 30 mm is formed in the upper case 3 at a position above the load cell 5 and in the vicinity of the pan bearing 7. Three are provided, and the three holes 3i are arranged at substantially equal intervals. The waterproof and dustproof breathable member 31 is glued to the outer peripheral edge of each hole 3i. It should be noted that the size, location, shape, number, and adhesion method of the waterproof and dustproof breathable member 31 are not limited to these examples.

  However, if the hole 3i has the largest possible area as in the above embodiment and is provided in the vicinity of the load cell 5 evenly, the compressed internal pressure escapes to the outside efficiently and quickly, and the response of the measurement result As a result, a more precise balance is realized. In addition, if the waterproof or dustproof and breathable member 31 has a seal shape in which the peripheral edge or the whole of the bonding surface with the hole 3i is glued in advance, the gluing operation to the hole 3i is unnecessary, and the waterproof and dustproof and breathable member 31 Installation workability is improved. Furthermore, each of the holes 3i and the waterproof and dustproof and breathable member 31 can be easily processed if the shape is circular.

  Another example of the waterproof and dustproof breathable member 31 is Gore-Tex (registered trademark) manufactured by Japan Gore-Tex. Gore-Tex is a material with a fine continuous porous structure obtained by drawing polytetrafluoroethylene (PTFE), which has the highest chemical stability among fluororesins. Dustproof and breathable. The waterproof and dustproof breathable member 31 may be a thin film member having waterproofness, dustproofness, and breathability, and is not limited to Microtex or Goretex.

  Nitto Denko catalogs describe that Microtex is used as an internal pressure adjusting filter for automobile parts, mobile phones, home appliances, OA equipment, outdoor equipment, etc. There are no examples of application to other weighing equipment. Further, there is no description about intentionally providing the hole 3i in the upper case 3 for the purpose of eliminating the measurement error of the load detection mechanism.

  Furthermore, by providing the hole 3i in the vicinity (for example, the upper side) of a place (heat generating part) where heat is likely to be generated such as a power source, a circuit (calculation unit 6b), a display unit 6c, etc. In addition to the waterproofing, dustproofing, and ventilation described above, it is possible to obtain a heat dissipation effect to the outside. This makes it possible to provide a dedicated heat sink or heat dissipation structure as in the past, or to store an electronic circuit board with a heat generating part that tends to cause load cell measurement errors in a separate location away from the load cell. It is no longer necessary to adopt the, and internal heat storage can be easily eliminated.

  The size, location, shape, number, etc. of the holes 3i can be freely designed according to the position of the heat generating portion and the amount of heat generated. However, in order to maintain the strength of the upper case 3 and reduce the processing cost, It is desirable to use both the vent hole and the heat dissipation hole.

  In the present embodiment, the structure in which the upper case 3 is covered with the cover 4 is adopted. However, even if the cover 4 covers the hole 3i, the cover 4 of the present embodiment is made of metal, so that the heat dissipation effect is further improved. Rise. Even with a scale without a cover 4, the sealed structure of the lower case 2 and the upper case 3 provides a waterproof and dustproof function and can be sufficiently practical as a scale. In the scale, the presence or absence of the cover 4 does not matter.

  Further, in the balance 1 having the diaphragm 8 of the present embodiment, the hole 3 i may be provided in the diaphragm 8. For example, the bellows 8b portion may be configured by the waterproof and dustproof breathable member 31 folded so as to be stretchable, and a base portion that does not adhere to the upper case 3 is provided on the outer periphery of the bellows 8b, and a hole is formed in the base portion. 3i may be provided, and the waterproof and dustproof breathable member 31 may be fixed to the hole 3i by bonding, pressure bonding, insert molding, outsert molding, or the like.

  As described above, since the upper case 3 of this embodiment has a waterproof and dustproof function, the cover 4 can be freely provided with an opening. As shown in FIG. 2, the top of the cover 4 of the present embodiment has an opening in a range that allows the top and bottom movements of the dish bearing 7 to pass through the top 7 b of the dish bearing 7, like the opening 3 d of the upper case 3. 4c is provided. When the upper case 3 and the cover 4 are fixed, as shown in FIG. 4, the upper surface of the base portion 8c of the diaphragm 8 and the lower surface of the cover 4 are in close contact or pressure-bonded, and the bellows 8b of the diaphragm 8 and the dish bearing 7 are opened from the opening 4c. The top portion 7c is exposed. Then, the weighing pan 10 is connected and fixed to the pan bearing 7 via the screw 10c, and the scale is assembled.

  Further, as shown in FIG. 2, the cover 4 is formed with an opening 4d in which a portion corresponding to the upper part of the liquid crystal screen of the display means 6c is opened in a substantially elliptical shape. Similarly, the upper case 3 exposed from the opening 4d corresponds to the upper part of the liquid crystal screen, and forms a display means equivalent portion 3k. The display means equivalent part 3k is integrally formed with the other part of the upper case 3 made of resin, but the part 3k is formed transparently by polishing or the like, and the upper case 3 and the cover 4 are fitted. It protrudes from the other surface of the upper case 3 for alignment.

  That is, the upper case 3 plays a role of protecting the liquid crystal screen of the display means 6c, and the internal display can be transmitted to the outside through the display means equivalent portion 3k of the upper case 3 so that the weighing person can visually recognize it. Since the display means equivalent part 3k is integrally formed with other parts as the upper case 3, a structure for sealing the display means 6c separately from other electronic parts is provided, or a protective cover for the display means is provided separately. There is no need to adopt, and assembly is easy.

  Further, after the upper case 3 and the cover 4 are fixed, or after the lower case 2 and the upper case 3 are fixed, a seal 32 is attached to the display means equivalent part 3k, and the lower case 2 support other than the liquid crystal screen is externally attached. It can be hidden. In the seal 32, a rectangular portion 32a corresponding to the liquid crystal screen of the display means 6c is transparent or open, and an operation key equivalent portion 32b is surrounded by a frame, etc., and a plurality of operation keys 6a are identified. Becomes easier. In addition, since the upper case 3 of the present embodiment has a substantially flat upper surface, the seal 32 is easily adhered and pasted onto the upper case 3 without being twisted or curved.

If the operation key equivalent portion 32b of the upper case 3 is provided with an opening for exposing the operation key 6a and a movable portion having an opening around the operation key 6a, the seal 32 opens the opening. Since the part and the movable part are covered and sealed, there is no possibility that the disturbance material enters the lower case 2 from the opening or the movable part.

  As mentioned above, although the example of a comparatively small electronic balance with a diaphragm has been described, the scale of the present invention is not limited to the scale provided with all the constituent elements described in the above example, and various modifications are possible. The balance of the present invention can be configured by arbitrarily combining the constituents necessary for realizing each object. It goes without saying that such changes and modifications also belong to the scope of the claims of the present invention.

  For example, in the above-described embodiment, the upper case 3 and the cover 4 are formed separately and independently, and the upper case 3 is assembled to the lower case 2 and the cover 4 is assembled to the upper case 3 sequentially. 3 may be integrally formed with the metal cover 4 by insert molding or outsert molding, whereby the number of assembling steps of the balance 1 is reduced. In this case, in the upper case 3, the outer peripheral frame 3 a covers the outer peripheral frame of the cover 4, and the display means equivalent portion 3 k of the upper case 3 is fitted into the hole 4 d of the cover 4. The diaphragm 8 and the waterproof and dustproof breathable member 31 are attached from the lower surface of the upper case 3.

  Further, in the above-described embodiment, the diaphragm 8 is used for sealing the inside of the lower case 2. However, if the upper case 3 has a structure capable of sealing the inside of the lower case 2, a scale without the diaphragm 8 can be used. Further, even a scale including a diaphragm having a configuration different from that of the above-described embodiment belongs to the scope of claims of the present invention. A diaphragm may be integrally formed on any of the upper case 3, the dish bearing 7, and the weighing dish 10.

Further, the scale of the present invention is a weight scale, a charge scale, a number scale, a platform scale, a height scale, etc., in addition to the electronic scale described in the embodiment, as long as it is a weighing device or a load scale having a load detection mechanism. Well, its name doesn't matter.

It is an external appearance perspective view which shows one Example of the balance concerning this invention. It is a disassembled perspective view which shows one Example of the balance concerning this invention. It is a partial assembly perspective view which shows one Example of the balance concerning this invention. It is a partial longitudinal cross-sectional view which shows one Example of the balance concerning this invention. It is a perspective view which shows one Example of a diaphragm.

Explanation of symbols

1: Scale 10: Weighing pan 10a: Platform 10b: Upper pan 10c: Screw 10d: Through hole 11: Scale body 2: Lower case 2a: Substrate fixing spacer 2b: Lower case support leg 2c: Outer frame 2d: Cylindrical spacer 3: upper case 3a: outer peripheral frame 3b: screw 3c: mounting hole 3d: opening 3e: annular groove 3f: recessed groove 3g: recessed groove 3h: boss 3i: hole 3j: recessed portion 3k: display means equivalent part 30: packing 31 : Waterproof and dustproof breathable member 32: Seal 32a: Rectangular portion 32b: Operation key equivalent portion 4: Cover 4a: Screw 4b: Screw hole 4c: Opening portion 4d: Opening portion 5: Load cell 6: Electronic circuit board 6a: Operation key 6b : Calculation means 6c: Display means 7: Countersink bearing 7a: Base part 7b: Screw hole 7c: Top part 7d: Annular groove 8: Diaphragm 8a: Through hole 8b: Bellows 8c: Base part 8d: Annular protrusion 8e: Caused 8f: protrusion 8 g: protrusions 9: O-ring

Claims (4)

In a scale composed of a weighing pan and a balance body,
The scale body is
A load detection mechanism connected to a lower portion of the weighing pan;
A calculation means for calculating a load value based on an output value of the load detection mechanism;
Display means for displaying the load value calculated by the calculation means and visible from the surface;
Operation keys that can perform various operations from the surface,
A lower case supporting the load detection mechanism, the calculation means, the display means, and the operation keys;
An upper case that is installed opposite to the lower case and seals the load detection mechanism, the calculation means, the display means, and the operation key to prevent intrusion of disturbance materials such as water and dust;
A metal cover that covers the upper case or a resin cover that is metal-plated on the surface,
A scale characterized by having. A concave portion is formed on the outer peripheral frame of the upper case,
The recess is fitted with a packing,
The scale according to claim 1, wherein the outer peripheral frame of the upper case is overlapped with the outer peripheral frame of the lower case. The scale according to claim 1 or 2, wherein the cover is made of stainless steel having high rigidity and corrosion resistance. The upper case is molded of a resin material, and a portion corresponding to the upper part of the display means is molded transparently,
The scale according to any one of claims 1 to 3, wherein the cover has an opening corresponding to an upper portion of the display means.

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