JP2005308656A - Waterproof dust-protected balance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waterproof dust-protected balance securing gas permeability required for enhancing measuring precision for a balance, while keeping air tightness necessary for waterproofness and dust protection. <P>SOLUTION: This balance 1 is provided with: a weighing dish 11; a load cell 13 connected to a lower part of the weighing dish 11; a case 15 for storing the load cell 13; and a waterproof dust-protected filter 3 for communicating an inside of the case 15 with an outside thereof while preventing water and dust from being intruded into the case 15. The waterproof dust-protected filter 3 comprises: an attaching tube 30 with one end 31 attached to a through hole 18 inside a recess 17 formed in an outer face of the case 15; and a filter part 32 having a communication port 34 with one end communicated with the other end of the attaching tube 30, and with the other end communicated with an outside of the case 15, and filled with a filtering member 33 in its inside. The communication port 34 is arranged in a lower side of the one end 31 of the attaching tube 30 and is adjacently opposed to an inner wall 19 of the recess 17. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a waterproof dustproof balance.

  2. Description of the Related Art Conventionally, a waterproof and dustproof balance has a balance body in which a load cell is stored in a casing, and a weighing pan is provided at a movable end of the load cell of the balance body via a tray receiving member. It is known to cover the space between the casings of the main body with a bellows.

  According to such a configuration, since the gap between the tray receiving member and the casing of the balance body is covered with the bellows, it is possible to completely prevent water and dust from entering the balance body.

  However, in the waterproof and dustproof balance having such a structure, since the airtightness in the casing is high, the vertical movement of the plate receiving member, the deflection of the mass sensor in the load cell, the opening and closing of the indoor door where the balance is placed, etc. With the occurrence of various events, a pressure difference is generated between the casing internal pressure and the external pressure, and this pressure difference becomes an error factor of the load cell as it is, and high measurement accuracy is obtained especially when measuring a small amount. It was difficult.

  Therefore, as described in Patent Document 1, conventionally, in a scale having a bellows as described above, one end opens to the outside of the bottom of the casing of the scale body, and the other end is in the casing. It is known to provide a cylindrical member that opens at the top.

  According to such a configuration, the air permeability of the balance is ensured through the cylindrical member, no differential pressure is generated between the casing internal pressure and the external atmospheric pressure of the scale main body, and from the opening at the bottom of the casing. A waterproof and dustproof balance with less water splash reaching the upper part in the casing is realized.

  However, such a balance has the following technical problems.

FIG. 1 of JP-A-11-258032

  Since the cylindrical member of the scale described in Patent Document 1 stands vertically with respect to the bottom surface of the casing, it is difficult to withstand the intrusion of water or dust that directly hits the opening from below. Met.

  On the other hand, for example, if the opening is narrowed and a high density filter member is filled in the opening, the pressure resistance against water and dust increases, but on the other hand, the air permeability decreases, so high accuracy measurement is possible. I couldn't do it.

The present invention has been made in view of such conventional problems, and the object of the present invention is to maintain the airtightness necessary for waterproofing and dustproofing while maintaining the air permeability necessary for improving the measurement accuracy of the balance. Another object is to provide a waterproof and dustproof balance.

  To achieve the above object, a waterproof and dustproof balance according to the present invention accommodates a weighing pan, a load detection mechanism connected to a lower portion of the weighing pan via a vertically movable tray bearing, and the load detection mechanism. A waterproof and dustproof balance comprising a case and a waterproof and dustproof filter that allows the inside and outside of the case to communicate with each other while preventing water and dust from entering the case. One end of the waterproof and dustproof filter is formed on the outer surface of the case A filter having a mounting tube to be mounted in a through hole in the recessed portion, a communication port that communicates with the other end of the mounting tube at one end and communicates with the outside of the case at the other end, and is filled with a filter member. The communication port is disposed below one end of the attachment pipe and is close to and opposed to the inner wall of the recess.

  According to the waterproof and dustproof balance configured as described above, the filter portion of the waterproof and dustproof filter has a communication port that communicates with the outside of the case, so that air permeability is ensured through the communication port. In addition, the communication port that can be an entrance for water and dust is in close proximity to the inner wall of the recess, and the gap between the communication port and the inner wall is small, so no matter what direction water or dust is injected from the communication port, Since the communication port is disposed below one end of the mounting pipe, it is difficult to enter higher than the position of the communication port. That is, according to the present invention, a waterproof and dustproof balance is realized in which air permeability necessary for improving the measurement accuracy of the balance is ensured and water and dust are less likely to enter from all directions.

  In addition, the concave portion may be provided in any place of the case, and the size is also arbitrary. Therefore, there is no design restriction and the degree of freedom in designing the scale is increased. Further, since there is no need to erect tall cylindrical members or raise the bottom as in the prior art, the scale can be reduced in size.

  A plurality of the communication ports may be provided.

  According to this structure, since the communication area is wide, in addition to the advantage of good air permeability and easy filling of the filter member, even if water enters from one of the communication ports, another communication is immediately established. Since it is discharged from the mouth, there is a merit that it is more effective by waterproofing. In addition, by providing a plurality of communication ports, it is possible to reduce the effective ventilation area at one location to increase waterproofness, and it is possible to ensure the air permeability with the total area of the communication ports.

  In addition, the through hole may be formed integrally with an inner wall of the concave portion on the outer periphery of the through hole, and the through hole may be provided at the bottom of the inclined surface.

  According to this configuration, since the through hole has an inclined surface that expands upward on the outer periphery, even if water or dust enters the waterproof dustproof filter, Is difficult to invade.

  The attachment tube may be a straight tube, and the filter portion may be a straight tube having both ends opened, and the attachment tube and the filter portion may be connected so as to be orthogonal to each other.

  According to this configuration, the shape of the waterproof and dustproof filter whose filter portion is a straight tube is a T-shape as a whole. Such a simple-shaped waterproof and dustproof filter is easy to manufacture, does not incur material costs, and can be mass-produced. Further, since there are two communication ports, not only the air permeability is good, but also the filter member is easily filled inside, and the filled filter member is difficult to fall off.

  The filter portion may have a flat plate shape in which a plurality of communication ports are provided on a side surface.

  According to this configuration, since a plurality of communication ports are provided, the filter member can be easily inserted therein, and the internal and external communication areas are widened, so that air permeability is further ensured and the accuracy of the scale is improved.

  The waterproof and dustproof filter may be detachable.

  According to this configuration, since it is detachable, cleaning around the through hole and replacement of the filter member can be easily performed.

  The waterproof and dustproof filter may be transparent.

  According to this configuration, since it is transparent, the degree of clogging of the filter member becomes clear at a glance, which is a guideline for replacing the filter member.

  In addition, the filter portion is formed with a ridge extending along the shape of the opening surface of the recess in a portion excluding the communication port, and the outer peripheral edge of the ridge is in close proximity to the inner wall of the recess. May be.

  According to this configuration, by providing the ridges in the filter portion, most of the opening surface of the concave portion is covered except for the gap necessary for the communication port to discharge the air inside the scale. Therefore, even if water or dust tries to enter from the outside, most of them do not enter the balance by hitting the bag, so that the waterproof and dustproof property is further improved while ensuring the air permeability of the balance.

  Further, the attachment tube may have a clamping claw projecting vertically on the outer periphery on the one end side with a thickness distance of a wall formed on the outer periphery of the through hole.

  According to this configuration, when the waterproof and dustproof filter is inserted into the through-hole from below, the clamping claw protruding upward passes through the through-hole and is locked on the slope, and the upper and lower clamping claw blocks the through-hole. The wall to be formed is sandwiched and securely fixed to the through hole. This prevents the waterproof and dustproof filter from falling off.

  The mounting tube has a notch formed in a part of the outer peripheral surface on the one end side, and the depth of the notch reaches the position of the upper nail in the nail. May be.

As described above, the attachment pipe is integrated with the surface formed on the outer periphery of the through hole by having the notch portion whose depth reaches the position of the upper clamping claw. Therefore, even if water or dust passes through the through-hole and enters the inside of the scale, the water or dust is smoothly transferred to the outside through the mounting tube integrated with the outer peripheral surface of the through-hole. The water and dust are less likely to stay on the outer periphery of the through hole.

  According to the waterproof and dustproof scale according to the present invention, the filter portion of the waterproof and dustproof filter has a communication port communicating with the outside of the case, so that air permeability is ensured through the communication port. In addition, the communication port that can be an entrance for water and dust is in close proximity to the inner wall of the recess, and the gap between the communication port and the inner wall is small, so no matter what direction water or dust is injected from the communication port, Since the communication port is disposed below one end of the mounting pipe, it is difficult to enter higher than the position of the communication port. That is, according to the present invention, a waterproof and dustproof balance is realized in which air permeability necessary for improving the measurement accuracy of the balance is ensured and water and dust are less likely to enter from all directions.

In addition, the concave portion may be provided in any place of the case, and the size is also arbitrary. Therefore, there is no design restriction and the degree of freedom in designing the scale is increased. Further, since there is no need to erect tall cylindrical members or raise the bottom as in the prior art, the scale can be reduced in size.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. FIG. 1A shows an embodiment of a waterproof dustproof balance according to the present invention, and is an internal longitudinal sectional view of the balance 1.

  As shown in FIG. 1A, a scale 1 according to the present embodiment includes a weighing pan 11, a load cell 13 (load detection mechanism) connected to a lower portion of the weighing pan 11 via a plate bearing 12 that moves up and down. The case 15 is configured to accommodate the load cell 13.

  Although not shown in detail, the weighing pan 11 is composed of a platform and an upper pan that covers the platform from above. The upper plate is generally 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 and agricultural products directly and ease of maintenance such as cleaning. It is molded with. The platform is generally formed of a resin material, has a screw through hole (not shown) in the center, and is connected to the countersunk bearing 12.

  In the present embodiment, the dish bearing 12 has a cylindrical shape, but the shape is not limited as long as the weighing dish 11 and the load cell 13 are connected and can move up and down.

  The load cell 13 is an embodiment of the load detection mechanism, and is configured by attaching a strain detection element (not shown) such as a strain gauge to the strain generating body, and when the weight of the object to be weighed is applied to the strain generating body. The generated tensile strain and compressive strain are electrically detected by a strain detection element. That is, the load value of the object to be weighed placed on the weighing pan 11 is detected as the output of the load cell 13 via the pan bearing 12 after detecting the operation of an operation key (not shown) such as a power switch or a weighing start key. After arithmetic processing is performed on a circuit board (not shown) on which an electric circuit component such as a bridge circuit is mounted, it is displayed on a display means (not shown) such as a liquid crystal display screen.

  As the load detection mechanism, in addition to the load cell 13 of the present embodiment, there are existing load sensors such as a capacitance sensor and a mass sensor, and various selections can be made according to the weighing, the object to be weighed, the application, etc. It is.

  The case 15 only needs to have a shape that can accommodate at least the load cell 13, and the case 15 of this embodiment has a substantially rectangular parallelepiped shape. In addition, although the case support leg 16 is provided in the four corners of the bottom face of the case 15, the present invention and the presence or absence of the case support leg 16 are irrelevant.

  Furthermore, since the scale 1 of this embodiment is intended for waterproofing and dustproofing, in order to prevent water and dust from entering the inside of the case 15 from the case opening provided in the outer periphery of the dish bearing 12, The gap between the bearing 12 and the case 15 is covered with a telescopic diaphragm 14.

  Further, the case 15 is constituted by a lower case and an upper case fitted to the lower case, although details are not shown. The outer frame of the lower case and the outer frame of the upper case are overlapped via packing, and the load cell 13 is sealed in the case 15.

  The scale 1 configured as described above certainly does not allow water or dust to enter the case 15 and looks perfect as a waterproof dustproof scale, but because the airtightness in the case 15 is high, The pressure between the internal pressure and the external air pressure of the case 15 is accompanied by various events such as vertical movement of the plate bearing 12, deflection of the mass sensor in the load cell 13, and opening and closing of the indoor door where the balance 1 is placed. A difference occurs, and this pressure difference becomes an error factor of the load cell 13 as it is, and it is difficult to obtain high measurement accuracy particularly when a minute amount is measured.

  Therefore, conventionally, as explained in the background art section, a cylindrical member having an open bottom is provided at the bottom of the case, and the inside and outside of the case are connected to ensure air permeability inside and outside the case, Although the intrusion of dust could be prevented, even in such a case, it was difficult to withstand the intrusion of water and dust that hit the opening of the cylindrical member directly.

  Therefore, in the present invention, in order to maintain the airtightness in the case 15 necessary for waterproof and dustproof and also to ensure the air permeability necessary for improving the measurement accuracy of the balance 1, a recess 17 is formed on the outer surface of the case 15. A through-hole 18 is provided in 17, and a waterproof and dust-proof filter 3 is attached so that the inside and outside of the case 15 can be communicated with each other to prevent air and dust from entering the case 15 and air permeability is ensured. It was to be.

  The waterproof and dustproof filter 3 shown in FIG. 1A is composed of an attachment tube 30 and a filter portion 32. Here, the attachment tube 30 has one end 31 attached to the through hole 18 and the other end communicating with the filter portion 32. The filter portion 32 has one end communicating with the other end of the attachment tube 30 and the other end having a communication port 34 communicating with the outside of the case 15 to prevent water or dust from entering by adhering or absorbing water and dust. Such a filter member 33 is filled inside.

  The waterproof and dustproof filter 3 is mounted in the through-hole 18 so that the communication port 34 of the filter portion 32 is disposed below the one end 31 of the attachment tube 30 and faces the inner wall 19 of the recess 17 in close proximity. FIG. 5 shows a view of the balance 1 shown in FIG. According to FIG. 5, it can be seen that the communication port 34 is in close proximity to the inner wall 19 of the recess 17. In this embodiment, the facing distance (gap) A between the communication port 34 and the inner wall 19 of the recess 17 is about 1.5 mm based on the total cross-sectional area of the two communication ports 34. This is because the air inside the scale 1 is reliably and smoothly discharged from the communication port 34 to the outside.

  According to the scale 1 having such a waterproof and dustproof filter 3, the filter portion 32 has the communication port 34 that communicates with the outside of the case 15, and thus air permeability is ensured through the communication port 34. Further, the communication port 34 that can be an entrance for water and dust is in close proximity to the inner wall 19 of the recess 17 and the gap between the communication port 34 and the inner wall 19 is small. However, it is difficult to enter from the communication port 34, and even if it has entered, the communication port 34 is disposed below the one end 31 of the attachment pipe 30, so that it enters higher than the position of the communication port 34. Hard to do. That is, according to the present invention, a waterproof and dustproof balance is realized in which air permeability necessary for improving the measurement accuracy of the balance is ensured and water and dust are less likely to enter from all directions. And the above thing does not depend on the installation position of the recessed part 17 or the waterproof dustproof filter 3. FIG. That is, according to the present invention, a waterproof and dustproof balance is realized which ensures air permeability necessary for improving the accuracy of the balance and prevents water and dust from entering from all directions.

  Further, in this embodiment, the concave portion 17 is formed in a substantially cylindrical shape having a diameter of 43 mm and a depth of about 20 mm so that a part of the bottom surface of the case 15 is depressed, and the inside and outside of the case 15 communicate with each other in the vertical direction through the through holes 18. However, the concave portion 17 may be formed in any place of the case 15 and is not restricted by design. Accordingly, the degree of freedom in designing the balance is increased, and there is no need to erect a tall cylindrical member or raise the bottom as in the conventional case, and the scale can be reduced in size.

  Further, in this embodiment, as shown in FIG. 1A, the through hole 18 is formed on the upper surface side inside the concave portion 17, but expands upward around the outer periphery of the through hole 18. A conical or funnel-shaped slope 20 having a height of about 20 mm is integrally formed on the inner wall 19 of the recess 17, and the through hole 18 is at the bottom of the slope 20.

  As a result, even if water and dust pass through the waterproof and dustproof filter 3 and enter the case 15 through the through-hole 18, the water and dust cannot resist gravity, so the slope that is the side of the cone On the other hand, since it is discharged to the outside of the case 15, the structure is such that water and dust do not easily enter higher than the position of the through hole 18.

  In addition, since the through hole 18 is isolated from the load cell 13 by the inner wall 19 of the recess 17, it is naturally difficult for water and dust to enter the vicinity of the load cell 13. In addition, the slope 20 should just be formed in the outer periphery of the through-hole 18, and the shape which makes the said slope 20 the side surface may be a pyramid shape besides a cone shape.

  Here, FIG.1 (b) is sectional drawing of the balance 1a which shows the Example different from the balance 1 of Fig.1 (a), About the components of the balance other than the case 15a and the waterproof dustproof filter 3, Since this is the same as that shown in FIG.

  In the scale 1a shown in FIG. 1B, a through hole 18a is formed at the center of the bottom surface of the case 15a, and the bottom surface of the case 15a is a cone that expands upward around the outer periphery of the through hole 18a. Or it becomes the slope of a funnel shape, and the through-hole 18a exists in the bottom part of the said slope. Further, a cylindrical recess 17a is formed to project from the bottom surface of the case 15a. A through hole 18a is formed on the upper surface side of the recess 17a, and the lower surface side is open.

  That is, when one end 31a of the attachment tube 30 of the waterproof and dustproof filter 3 is inserted into the through hole 18a, the communication port 34a of the filter portion 32a is disposed below the one end 31a of the attachment tube 30a, and the inner wall 19a of the recess 17a Proximity comes to face. Thereby, the air permeability necessary for improving the accuracy of the balance is ensured, and the waterproof and dustproof balance is less likely to allow water and dust to enter from all directions.

  In addition, even if water or dust passes through the waterproof and dustproof filter 3 and enters the case 15a from the through hole 18a, the water or dust does not resist gravity, so the case 15a has a slope. On the other hand, since it is discharged to the outside of the case 15a, the structure is such that water and dust do not easily enter higher than the position of the through hole 18a.

  Next, the details of the waterproof and dustproof filter 3 used in the scales 1 and 1a shown in FIG. 1 will be described with reference to FIG. 6A. The mounting tube 30 has a length of about 17 mm, a tube outer diameter of 7 mm, It is a straight tube with a tube inner diameter of φ5 mm.

  The filter portion 32 is a tube having a length of about 40 mm and having the same inner and outer diameters as the previous attachment tube 30. The filter portion 32 is a straight tube having both ends open, that is, two communication ports 34. Since there is a communicating portion with the mounting tube 30, the waterproof and dustproof filter 3 as a whole is T-shaped.

  Such a simple-shaped waterproof and dustproof filter 3 is easy to manufacture, does not incur material costs, and can be mass-produced. Moreover, since there are two communication ports 34, not only the air permeability is good, but the filter member is easily filled inside, and the filled filter member is difficult to fall off.

  It should be noted that the waterproof and dustproof filter 3 is not limited to the shape of the waterproof and dustproof filter 3 of the present embodiment, but if it is a waterproof and dustproof filter having a plurality of communication ports 34, in addition to the advantages of good air permeability and easy filling of the filter member, any Even if water enters from one communication port 34, it can be discharged from another communication port 34, and there is a merit that it is more effective for waterproofing. In addition, by providing a plurality of communication ports 34, it is possible to reduce the effective ventilation area at one location to improve waterproofness, and to ensure air permeability with the total area of the communication ports 34.

  Further, a locking ring 35 is formed in an annular shape on one end 31 side of the mounting tube 30 of the waterproof and dustproof filter 3 of FIG. 6A, and a predetermined length of the mounting tube 30 is press-fitted into the through hole 18. At that time, the waterproof and dustproof filter 3 is locked. 6A, an annular protrusion (not shown) for press-fitting and fixing is formed on the one end 31 side of the mounting tube 30 in addition to the locking ring 35. The mounting form to 18 is not limited to this.

  These waterproof and dustproof filters 3 and 3a are detachable, and can be freely attached to and detached from the through hole 18. As a result, the waterproof and dustproof filters 3 and 3a can be removed from the through hole 18, and the periphery of the through hole 18 can be easily cleaned and the filter member 33 can be easily replaced.

  Further, since the waterproof and dustproof filters 3 and 3a of the present embodiment are made of transparent resin, the degree of clogging of the filter member 33 becomes obvious at a glance, and becomes a guide when the filter member 33 is replaced.

  Here, the filter member 33 may be a commercially available product that is also used as an air filter for commercial / home air conditioners, or a filter for electrical appliances such as an electrostatic precipitator, a deodorizer, and the like. An Everlight Scott filter manufactured by Manufacture Co., Ltd. is preferred. In order to further improve the waterproof property, for example, a highly water-repellent filter member such as Teflon (registered trademark) can be used.

  In general, increasing the cell density of the filter member 33 increases the airtightness in the case 15 and is effective in preventing water and dust from entering from the outside. Since the air permeability deteriorates, the accuracy of the balance is not necessarily improved. On the other hand, in the scale of the present invention, by providing the waterproof and dustproof filters 3 and 3a, a structure in which water and dust do not easily enter is adopted. Therefore, the cell density of the filter member 33 is increased to the ideal waterproof and dustproof state. There is no need to do so, and in this sense, a commercially available material having a cell density of the degree used for an electric appliance can be used as the filter member 33.

  The scale 1 having the above-described configuration clears the test of the IP65 standard (compliant with the IEC international standard, JIS 5 class), which is also called the highest grade of the waterproof and dustproof standard at the time of this application, and the weight of 8 to 30 kg is set to 0. It became possible to measure with high accuracy of 01 g to 0.1 g. Here, the scale 1 of the present embodiment is a weight built-in type, and only about 850 g of built-in weight can be used to correct the weight of 8 kg. Therefore, in order to obtain a weighing accuracy of 8 kg × 0.01 g, an accuracy of about 0.001 g is required at 850 g, and the total accuracy including the built-in weight is 8 kg × 0.001 g, that is, 1/8 million. (Note that the maximum resolution in the weighing display is 1 / 800,000).

  In order to clear the IP65 standard, a nozzle with an inner diameter of 6.3 mm was used to pour water for 3 minutes at a flow rate of 12.5 liters / minute in all directions from a distance of 3 m to the DUT. , It is required that the DUT is normal.

The reason why such a high-precision waterproof and dustproof scale has been realized is largely due to the adoption of the waterproof and dustproof filter 3, and there is no other such scale in the measuring instrument industry at the time of this application. The scale 1 of the present embodiment is almost equal to that guaranteed to be suitable for use in places with a lot of moisture and dust, such as the food industry, the pharmaceutical industry, and the cement industry, and contributes to the expansion of the product market.

  Next, another embodiment of the present invention will be described. The scales 1b, 1c, and 1d shown in the internal vertical cross-sectional views of FIGS. 2 to 4 use the waterproof and dustproof filter 3 as in the previous embodiment to ensure the air permeability and prevent water and dust from all directions. 1 is an example of a scale having a structure that does not easily enter the scale 15, but the form of the scale excluding the form of the recess 17 formed in the case 15 and the form of the waterproof and dustproof filter 3 is the scale 1 shown in FIG. The description is omitted here.

  The concave portion 17b of the scale 1b shown in FIG. 2 is formed so that the outer surface of the case 15b is recessed from the upper surface side of the case 15b, and has a substantially cylindrical shape with a diameter of 43 mm and a concave portion depth of about 20 mm when viewed from the outer surface of the case 15c. doing. Further, the bottom surface portion 21b at the lowest position of the inner wall 19b forming the concave portion 17b has a conical shape that is contracted downward, and a bottom surface hole of the case 15b is connected to the bottom portion thereof via the communication passage 23b. 22b.

  The through-hole 18b that communicates the inside and outside of the case 15b is provided on the vertical side surface of the inner wall 19b of the recess 17b, and the waterproof and dustproof filter 3b is attached to the through-hole 18b.

  FIG. 6B shows an enlarged view of the waterproof and dustproof filter 3b of the present embodiment. The attachment tube 30b of the waterproof and dustproof filter 3b shown in FIG. 6B includes a horizontal portion 36b, an inclined portion 37b that communicates with the horizontal portion 36b and is inclined downward, and a vertical portion 38b that communicates with the inclined portion 37b. The end of the horizontal portion 36b that does not communicate with the inclined portion 37b is attached to the through hole 18b as one end 31b of the mounting tube 30b, and the end of the vertical portion 38b that does not communicate with the inclined portion 37b. The other end becomes the other end of the attachment tube 30b and communicates with the filter portion 32b.

  The filter portion 32b is a straight tube having communication ports 34b at both ends, similar to the filter portion 32 of FIG. 6A. The vertical portion 38b of the attachment tube 30b communicates with the center of the straight tube, and is orthogonal to the attachment tube 30b. To be connected. The length of the filter part 32b is determined to be close to each other so that the communication port 34b of the filter part 32b does not contact the inner wall 19b of the recess 17b. Conversely, the length of the filter portion 32b may be determined first, and the size of the recess 17b may be determined later. The filter portion 32b is filled with a filter member 33 as in the previous embodiment.

  By attaching one end 31b to the through hole 18b, the communication port 34b is connected to the through-hole 18b so that the communication port 34b of the filter portion 32b is disposed below the one end 31b of the attachment tube 30b. Of the inner wall 19b that forms the recess 17b, it faces and opposes the vertical side surface. As a result, a scale is obtained in which water and dust are less likely to enter the case 15b and air permeability is ensured.

In the case where the concave portion 17b is formed on the upper surface side of the case 15b as in this embodiment, water and dust enter the concave portion 17b and stay there, and finally pass through the waterproof and dustproof filter 3b. As described above, by providing the communication passage 23b that communicates with the outside on the bottom surface 21b side, water and dust can enter the recess 17b. Staying can be avoided.

  The concave portion 17c of the scale 1c shown in FIG. 3 is formed on the side surface side of the case 15c, and is 43 mm in length and width, and the depth of the concave portion 17c viewed from the outer surface of the case 15c is about 20 mm. And the through-hole 18c which connects the inside and outside of the case 15c is provided in the side surface of the center side of the case 15c among the inner walls 19c which form the recessed part 17c, and the waterproof dustproof filter 3c is attached to this through-hole 18c. The

  FIG. 6C shows an enlarged view of the waterproof and dustproof filter 3c of this example. The attachment tube 30c of the waterproof and dustproof filter 3c shown in FIG. 6C has a horizontal portion 36c and an inclined portion 37c that communicates with the horizontal portion 36c and is inclined downward, as in FIG. 6B. That is, in the present embodiment, the end of the horizontal portion 36c that does not communicate with the inclined portion 37c is attached to the through hole 18c as one end 31c of the mounting tube 30c, and the horizontal portion 36c of the inclined portion 37c is mounted. The end not communicating with the other end is the other end of the attachment tube 30c and communicates with the filter portion 32c.

  Further, the waterproof and dustproof filter 3c in FIG. 6C is provided with a locking ring 35c on the outer periphery of the horizontal portion 36c of the mounting tube 30c, as in FIG. 6A, and the locking ring 35c is a mounting tube. When 30c is attached to the through hole 18c, the inner wall 19c surface of the recess 17c is locked, and the excessive insertion of the attachment tube 30c is prevented. The filter portion 32c is a straight tube having communication ports 34c at both ends, similarly to the filter portion 32 of FIGS. 6 (a) and 6 (b), and is connected so as to be orthogonal to the mounting tube 30c at the center.

Similarly to the previous embodiment, such a waterproof and dustproof filter 3c also has one end 31c attached to the through hole 18c so that the communication port 34c of the filter portion 32c is disposed below the one end 31c of the attachment tube 30c. As a result, the communication port 34c is close to and faces the vertical side surface of the inner wall 19c forming the concave portion 17c, and a scale that is difficult for water and dust to enter the case 15c and has sufficient air permeability is completed. .

  The recess 17d of the scale 1d shown in FIG. 4 is formed on the side surface of the case 15d as in the embodiment shown in FIG. 3, and is 43 mm in length and width, and the depth of the recess 17d when viewed from the outer surface of the case 15d is about 20 mm. And the through-hole 18d which connects the inside and outside of the case 15d is provided in the center side surface of the case 15d among the inner walls 19d forming the recess 17d, and the waterproof and dustproof filter 3c is attached to the through-hole 18d. . This is also the same as the embodiment shown in FIG.

  An enlarged view of the waterproof and dustproof filter 3d of the present embodiment is shown in FIG. The attachment tube 30d of the waterproof and dustproof filter 3d shown in FIG. 6 (d) is a straight tube having a length of about 20 mm, and the filter portion 32d is a straight tube having a length of about 20 mm. Connected. The overall shape of the waterproof and dustproof filter 3d of this embodiment is L-shaped, and the communication port 34d of the filter portion 32d is provided at one location. In the waterproof and dustproof filter 3d shown in FIG. 6D, the filter member 33 is filled not only in the filter portion 32d but also in the attachment tube 30d, but such a case may be used.

  Therefore, when the waterproof and dustproof filter 3d of the present embodiment is attached to the through hole 18d such that the communication port 34d of the filter portion 32d is disposed below the one end 31d of the attachment tube 30d, the communication port 34d is Of the inner wall 19d forming the concave portion 17d, it is close to and opposed to the horizontal bottom surface. Then, a scale is obtained in which water and dust are less likely to enter the case 15d and air permeability is ensured.

  Further, FIG. 6 (e) shows another embodiment of the waterproof and dustproof filter 3, and the waterproof and dustproof filter 3e of this embodiment is a communication between the mounting tube 30e having a length of about 20 mm and the mounting tube 30e. And a filter portion 32e to which two tubes having a length of about 20 mm inclined downward from the portion are connected. In the present embodiment, the communication port 34e has two locations, and has a Y-shape as a whole.

  The waterproof and dustproof filter 3e shown in FIG. 6 (e) has a condition that the communication port 34e of the filter portion 32e is disposed below the one end 31e of the mounting tube 30e and is in close proximity to the inner wall 19 of the recess 17. As long as it is satisfied, it can be installed in any through hole 18 in any recess 17, but generally it is desirable to install in any through hole 18 provided on the upper surface side as shown in FIG. 1. .

  FIG. 6 (f) shows another embodiment of the waterproof and dustproof filter 3, and the waterproof and dustproof filter 3 f of this embodiment has a connection portion between the attachment tube 30 f having a length of about 20 mm and the attachment tube 30 f. It has a filter part 32f to which two pipes having a length of about 20 mm inclined upward are connected as a bottom part. In the present embodiment, the communication port 34f has two places, and has a bowl shape as a whole. When the filter portion 32f is mounted in the through hole 18 so that the one end 31f of the mounting tube 30f is on the upper side and the mounting tube 30f is vertical, the communication port 34f is connected to the one end 31f of the mounting tube 30f. It will be in the state of being arranged on the lower side.

  The waterproof and dustproof filter 3f shown in FIG. 6 (f) has a condition that the communication port 34f of the filter portion 32f is disposed below the one end 31f of the mounting tube 30f and is in close proximity to the inner wall 19 of the recess 17. As long as it is satisfied, it can be installed in any through hole 18 in any recess 17, but generally it is desirable to install in any through hole 18 provided on the upper surface side as shown in FIG. 1. .

  Even when the waterproof dustproof filter 3f having a bowl shape as in the present embodiment is attached to the through hole 18 of the scale 1 shown in FIG. 1, water and dust can enter the case 15 through the communication port 34f. And air permeability is maintained. In addition, since the opening surface of the communication port 34f of the waterproof and dustproof filter 3f of the present embodiment is not parallel to the inner wall 19 of the recess 17 but is inclined upward, water and dust are less likely to enter.

  Even if the communication port 34f is in close proximity to the inner wall 19 of the recess 17, water may enter from the communication port 34f and stay in the two pipes constituting the filter portion 32f. However, when water tries to enter beyond the capacity of the filter portion 32f, the water is naturally discharged from the communication port 34f, and the communication port 34f is disposed below the one end 31f of the attachment tube 30f. Therefore, the water does not enter higher than the position of the communication port 34f due to the pressure balance inside and outside the case 15. That is, the waterproof and dustproof filter 3f of the present embodiment also has a structure in which water does not easily enter the case 15.

  An example of the simplest waterproof and dustproof filter 3 is shown in FIG. The waterproof and dustproof filter 3g shown in FIG. 7 (a) is a simple straight tube in which the mounting tube 30g and the filter portion 32g are in a straight line, but the tip of the filter portion 32g is closed. One or more communication ports 34g are provided on the peripheral side surface. In the waterproof and dustproof filter 3 shown in FIG. 7A, the boundary between the mounting tube 30g and the filter portion 32g is not particularly determined, and the entire inside of the waterproof and dustproof filter 3 is filled with the filter member 33. .

  Further, FIG. 7B shows another embodiment of the waterproof and dustproof filter 3. The waterproof and dustproof filter 3h of the present embodiment has a flat plate-shaped filter portion 32h connected to the other end of the mounting tube 30h, and a plurality of communication ports 34h are provided at predetermined intervals on the side surface of the filter portion 32h. The filter member 33 is filled into the filter portion 32h via the communication port 34h. The shape of the filter portion 32h may be a disk shape as well as a disk shape as in the present embodiment.

Such a waterproof and dustproof filter 3h is attached to, for example, the through hole 18 in the concave portion 17 of the scale as shown in FIG. Since the waterproof and dustproof filter 3h according to the present embodiment has a large number of communication ports 34h, the filter member 33 can be easily inserted therein, the internal and external communication areas are widened, air permeability is ensured, and the accuracy of the scale is improved.

  The waterproof and dustproof filter 3i shown in FIGS. 8B to 8D is made of resin, and has a length of about 17 mm, a pipe outer diameter of 7 mm, and a pipe inner diameter of 5 mm as in the waterproof dustproof filter 3 of FIG. The tube 30i is provided with a filter part 32i having two communication ports 34i having a length of about 40 mm and the same inner and outer diameter as the attachment tube 30i and having both ends opened. The filter portion 32i has a communication portion with the attachment tube 30i in the center, and is connected to be communicated so as to be orthogonal to the attachment tube 30i. The attachment tube 30i and the filter portion 32i have a T shape as a whole. 8 (b) is a perspective view of the waterproof and dustproof filter 3i, FIG. 8 (c) is a sectional view taken along the line CC of FIG. 8 (b), and FIG. 8 (d) is FIG. It is a right view of (b).

  Here, the pipe outer diameter of the attachment pipe 30i is substantially the same as the diameter of the through hole 18i of the scale 1i shown in FIG. 8 (a). The nail | claw 40i protrudes up and down across the thickness distance of the wall currently formed in the outer periphery.

  Furthermore, a part of the outer peripheral surface on the one end 31i side is cut away, and a plurality of cutout portions 41i are formed. The depth of the notch 41i reaches the position of the upper clamping claw 40i among the clamping claws 40i projecting up and down on the attachment tube 30i.

  When the waterproof and dustproof filter 3i configured as described above is inserted into the through hole 18i of the scale 1i from below as shown in FIG. 8 (a), the holding claw 40i protruding upward is made by the elasticity of the resin. Passing through the through-hole 18i and locking onto the slope 20, the upper and lower clamping claws 40i sandwich the slope 20i forming the through-hole 18i and are securely fixed to the through-hole 18i. This prevents the waterproof and dustproof filter 3i from falling off.

  Even if the waterproof and dustproof filter 3i is once fixed to the through hole 18i, the waterproof and dustproof filter 3i of the present embodiment is made of resin and has the cutout portion 41i. The filter member 33 can be easily removed from the through hole 18i when the filter member 33 is replaced.

  Further, the attachment pipe 30i is formed on the outer periphery of the through hole 18i because the one end 31i does not have a complete cylindrical shape and has a cutout portion 41i that reaches the holding claw 40i protruding upward. Integrated with the inclined surface 20i. Therefore, even if water or dust passes through the through-hole 18i and enters the inside of the scale 1i, the water or dust is concentrated on the central through-hole 18i down the slope 20i, and the slope 20i. It is smoothly discharged to the outside through the mounting tube 30i integrated with the. Water and dust are less likely to stay on the outer periphery of the through hole 18i, that is, on the slope 20i.

  Further, on the lower surface side of the filter part 32i, a substantially circular ridge 42i having a diameter of 40 mm, in which a total of three semicircular cutout parts 43i and 44i are formed, is formed to extend to a portion excluding the communication port 34i. Has been.

  The flange 42i is formed following the shape of the bottom surface, which is the opening surface of the recess 17i, and the outer peripheral edge of the flange 42i and the communication port 34i are in close proximity to the inner wall 19i of the recess 17i. . Specifically, the facing distance (gap) B between the outer peripheral edge of the flange 42i and the inner wall 19i is about 1.5 mm. The facing distance B is determined based on the total cross-sectional area of the two communication ports 34i so that the air inside the scale 1i is reliably and smoothly discharged from the communication port 34i to the outside.

  The notch 43i is formed in a semicircular shape with a diameter of 5 mm and makes it easier for air discharged from the communication port 34i to escape to the outside. Further, the notch 44i is formed following the shape of the bottom surface of the scale 1i of the embodiment, and is not formed mainly for discharging air to the outside. The shape of the flange 42i is not limited to that of the present embodiment, and the presence or absence of the notches 43i and 44i is arbitrary.

In this way, by providing the flange 42i in the filter part 32i, most of the opening surface of the recess 17i is covered except for the gap necessary for the communication port 34i to discharge the air inside the scale 1i. Become. Therefore, even if water or dust tries to enter from the outside, most of them do not enter the balance 1i by hitting the ridge 42i, so that the waterproof and dustproof property is further improved while ensuring the air permeability of the balance 1i.

  As described above, the embodiment of the waterproof and dustproof balance has been described. However, the waterproof and dustproof balance of the present invention is not limited to the waterproof and dustproof balance provided with all of the configuration requirements described in the above embodiment, and various changes and modifications are possible. Is possible. 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 specification, a plurality of possible forms of the waterproof and dustproof filter 3 have been described with reference to the drawings. However, the present invention is not necessarily limited to the form described here, and some forms of the waterproof and dustproof filter 3 of each embodiment Also, when a form not described in the specification is arbitrarily combined to form a new waterproof and dustproof filter, the communication port 34 of the filter portion 32 is disposed below the one end 31 of the mounting tube 30, and the recess 17 As long as even the condition of facing the inner wall 19 is met, it is included in the present invention. In addition, it is optional whether the filter member 33 is filled not only in the filter portion 32 but also in the mounting tube 30.

It is an internal longitudinal cross-sectional view which shows one Example of the balance concerning this invention. It is an internal longitudinal cross-sectional view which shows one Example of the balance concerning this invention. It is an internal longitudinal cross-sectional view which shows one Example of the balance concerning this invention. It is an internal longitudinal cross-sectional view which shows one Example of the balance concerning this invention. It is the figure which looked at the balance of FIG. 1 from the bottom face side. It is a perspective view which shows one Example of a waterproof dustproof filter. It is a perspective view which shows one Example of a waterproof dustproof filter. It is the perspective view, sectional drawing, and side view which show one Example of a waterproof dustproof filter.

Explanation of symbols

1: Scale 11: Weighing pan 12: Plate bearing 13: Load cell 14: Diaphragm 15: Case 16: Case support leg 17: Recess 18: Through hole 19: Inner wall 20: Slope 3: Waterproof dustproof filter 30: Mounting tube 31: One end 32: Filter part 33: Filter member 34: Communication port 35: Locking ring 40: Holding claws 41, 43, 44: Notch part 42: ridge

Claims (10)

A weighing pan, a load detection mechanism connected to a lower portion of the weighing pan via a freely movable plate bearing, a case housing the load detection mechanism, and preventing water and dust from entering the case. A waterproof dustproof scale equipped with a waterproof dustproof filter that allows communication between the inside and outside of the case,
The waterproof and dustproof filter is
A mounting tube having one end attached to a through hole in a recess formed on the outer surface of the case;
One end communicates with the other end of the mounting pipe, the other end has a communication port communicating with the outside of the case, and comprises a filter part filled with a filter member inside,
The waterproof and dustproof balance is characterized in that the communication port is disposed below one end of the attachment pipe and is in close proximity to the inner wall of the recess. The waterproof dustproof balance according to claim 1, wherein a plurality of the communication ports are provided. The said through-hole is integrally formed in the inner wall of the said recessed part in the outer periphery at the outer periphery, and the said through-hole exists in the bottom part of the said slope. The waterproof dustproof scale described in 1. The mounting tube is a straight tube,
The filter part is a straight tube having both ends opened,
The waterproof and dustproof balance according to any one of claims 1 to 3, wherein the attachment pipe and the filter portion are connected in communication so as to be orthogonal to each other. The waterproof dustproof balance according to any one of claims 1 to 3, wherein the filter portion has a flat plate shape in which a plurality of communication ports are provided on a side surface. The waterproof and dustproof balance according to any one of claims 1 to 5, wherein the waterproof and dustproof filter is detachable. The waterproof and dustproof balance according to any one of claims 1 to 6, wherein the waterproof and dustproof filter is transparent. The filter portion is formed with a ridge extending in accordance with the shape of the opening surface of the concave portion in a portion excluding the communication port,
The waterproof and dustproof balance according to any one of claims 1 to 7, wherein an outer peripheral edge of the ridge is in close proximity to an inner wall of the recess. The clamping tube projects vertically on the outer periphery on the one end side with a thickness distance of a wall formed on the outer periphery of the through-hole. Item 9. The waterproof and dustproof balance according to any one of Items 8. The mounting pipe has a notch formed in a part of the outer peripheral surface on the one end side,
The waterproof dustproof balance according to claim 9, wherein the depth of the notch reaches the position of the upper clamping claw among the clamping claws.

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