JP6258187B2 - Double box water meter and method of assembling its inner case - Google Patents

Description

  The present invention relates to a double box type water meter in which an interior of a lower case is separated into an upstream chamber and a downstream chamber by a watertight ring, and a method for assembling the inner case.

  The double box water meter (hereinafter simply referred to as “water meter”) is divided into an upper chamber and a downstream chamber inside the lower case, and an inner case is arranged across both chambers. After the tap water that has flowed into the measuring chamber inside is measured by rotating the impeller, the tap water is discharged to the downstream chamber.

  The structure in which the inside of the lower case is separated into the two chambers is roughly divided into a “partition wall structure” in which a partition wall is provided inside the lower case and the partition wall supports the central portion in the height direction of the inner case. The inner case housing space is formed in a hollow cylindrical shape, and a specific portion between the outer peripheral surface of the inner case and the inner peripheral surface of the inner case housing space is sealed with a watertight packing, so that the lower case is separated into both chambers. Some have "watertight packing structure".

  As one of the latter “watertight packing structures”, the one disclosed in Patent Document 1 is known. In the one disclosed in Patent Document 1, the inside of the lower case is separated into both chambers by disposing the watertight packing at the outlet portion of the inner case, so that the inner case can be assembled. By inserting a wedge body into the gap between the outer peripheral surface of the inner case accommodated with a predetermined gap and the inner peripheral surface of the inner case accommodating space, the inner case is slightly moved in the radial direction, and the watertight packing is It is compressed and deformed to achieve watertightness.

JP 2014-95611 A

  In the double box water meter in which the inside of the lower case is separated into the upstream chamber and the downstream chamber by a watertight ring, the present invention facilitates the assembly of the inner case to the lower case and improves the watertightness of the watertight packing. Is an issue.

The invention of claim 1 for solving the above-mentioned problem is that an inner case housing space is formed in a case main body portion between an inlet pipe and an outlet pipe formed in the lower case with the same axial center. A double box water meter having a configuration in which a measuring chamber is formed inside and each nozzle for inflow and outflow is formed,
On the outer peripheral surface of the inner case, a packing housing groove having a portion inclined with respect to the rotational axis of the impeller disposed in the measuring chamber is formed,
By being accommodated in the packing accommodating groove, the interior of the lower case is upstream of an unmetered tap water accommodated by a watertight packing having a portion that is partially inclined with respect to the rotational axis of the impeller. The side chamber and the downstream side chamber in which the measured tap water is accommodated are separated from each other in a watertight manner.

  According to the first aspect of the present invention, a packing housing groove having a portion inclined with respect to the rotational axis of the impeller disposed in the measuring chamber is formed on the outer peripheral surface of the inner case, and is housed in the packing housing groove. Thus, the interior of the lower case includes an upstream chamber in which unmetered tap water is accommodated, and a metered tap water by means of a watertight packing having a part inclined with respect to the rotational axis of the impeller. Since the downstream chamber in which water is accommodated is separated from the downstream chamber in a watertight manner, the inner case accommodation space provided in the lower case can be circular in cross section over the entire height. As a result, the shape of the inner case housing space provided in the case main body portion of the lower case is simplified, and the shape of the entire inner case is correspondingly simplified as a cylindrical shape. As a result, the watertightness of the watertight packing separated into the downstream side and the downstream side can be improved, and the lower case and the inner case constituting the double box water meter can be easily designed and manufactured.

  According to a second aspect of the present invention, in the first aspect of the present invention, the packing receiving groove formed on the outer peripheral surface of the inner case is elliptical, and the whole of the watertight packing is located at the rotational axis of the impeller. It is characterized by being arranged on an elliptical surface inclined with respect to the surface.

  According to the invention of claim 2, the curved state of the watertight packing is gradually changed over the entire circumference by the entire watertight packing being arranged in an elliptical shape. Therefore, excessive force does not act on the watertight packing, and high watertightness can be maintained over a long period of time.

  According to a third aspect of the present invention, in the first or second aspect of the invention, the peripheral wall body of the inner case is divided into two vertically in the packing housing groove, and the upper and lower peripheral wall body divided bodies are assembled together to accommodate the inner case housing. In a state where the inner case is accommodated in the space, the watertight packing accommodated in the packing accommodating groove formed between the lower end surface of the upper peripheral wall segment and the upper end surface of the lower peripheral segment is compressed from above. Thus, the water-tight packing is bulged and deformed outward in the radial direction of the peripheral wall body, and is in close contact with the inner peripheral surface of the inner case housing space.

  According to the invention of claim 3, in the middle of accommodating the inner case in the inner case accommodating space of the lower case, the temporary packing accommodating groove between the lower end surface of the upper peripheral wall segment and the upper end surface of the lower peripheral segment. No compressive force is applied to the watertight packing accommodated in the inner space, and a predetermined gap is formed between the packing and the inner peripheral surface of the inner case accommodating space. The inner case can be stored smoothly. After the housing, when the pressure receiving plate covering the upper end opening of the inner case is pressurized by the pressure receiving plate holding ring, the width (the dimension in the height direction) of the temporary packing housing groove for housing the watertight packing is narrowed. By forming the original packing housing groove, the watertight packing bulges outward in the radial direction of the inner case, and comes into close contact with the inner peripheral surface of the inner case housing space of the lower case. Is planned.

  The invention of claim 4 is characterized in that, in the invention of claim 3, the cross-section of the packing receiving groove has a triangular shape which expands toward the outer peripheral surface of the inner case.

  According to the invention of claim 4, since the shape of the packing receiving groove is a triangular shape that is expanded toward the outer peripheral surface side of the inner case, at the time of compressive deformation of the watertight packing stored in the packing receiving groove. Since the water-tight packing hardly bulges inward in the radial direction of the inner case, the water-tight packing bulges outward in the radial direction, so that adhesion to the inner peripheral surface of the inner case accommodation space is improved.

  According to a fifth aspect of the present invention, in the third or fourth aspect of the invention, the upper end portion of the upper peripheral wall body is closely attached to a step portion formed at the upper end portion of the inner case housing space via a watertight packing. The pressure receiving plate is integrally formed.

  According to the invention of claim 5, since the upper peripheral wall divided body and the pressure receiving plate portion are integrated, the compression of the watertight packing is ensured, and the number of parts is reduced.

The invention of claim 6 is a method of housing and assembling the inner case of the double box water meter according to claim 3 in the inner case housing space of the lower case,
Temporary assembly in which watertight packing is disposed in a non-compressed state in a temporary packing housing groove between the lower end surface of the upper peripheral wall segment and the upper end surface of the lower peripheral wall segment by temporarily assembling the upper and lower peripheral wall segments After the inner case is accommodated in the inner case accommodating space, the pressure-receiving plate is pressed downward by the pressure-receiving plate retaining ring, so that the watertight packing is bulged and deformed outward in the radial direction of the inner case, and the inner case is accommodated. It is characterized by being in close contact with the inner peripheral surface of the space.

  According to the invention of claim 6, when the inner case is accommodated in the inner case accommodating space of the lower case, the upper and lower case divided bodies are temporarily assembled to form the inner case, and the inner case is formed into the inner case. When accommodated in the case accommodating space, the watertight packing accommodated in the temporary packing accommodating groove of the inner case is not compressed and deformed, and therefore, between the watertight packing and the inner peripheral surface of the inner case accommodating space. Since the slight gap is generated, the inner case can be accommodated smoothly, and after the inner case is completely accommodated, the upper peripheral wall segment is slightly closer to the lower peripheral segment. The width of the temporary packing housing groove is narrowed to form a normal packing housing groove. As a result, the water-tight packing is compressed and deformed and bulges outward in the radial direction of the inner case, and comes into close contact with the inner peripheral surface of the inner case housing space, so that the inside of the lower case is water-tight to the upstream chamber and the downstream chamber. Hold and separate. As a result, the assembly work of the inner case with respect to the lower case is facilitated.

In the invention of claim 7, an inner case housing space having a circular cross section is formed in a case body portion between an inlet pipe and an outlet pipe formed in the lower case with the same axis, and the inner case is A double box type water meter having a configuration in which a measuring chamber is formed inside and each nozzle for inflow and outflow is formed,
The inner peripheral part of the inner case housing space of the case main body part and the outer peripheral part of the inner case have portions inclined with respect to the rotation axis of the impeller that is rotatably arranged in the measuring chamber. , Step portions corresponding to each other are formed,
The inside of the lower case is unmetered by the watertight packing having a portion that is partially inclined with respect to the rotational axis of the impeller by being accommodated in the packing accommodating groove between the step portions. The upstream side chamber in which water is accommodated and the downstream side chamber in which measured tap water is accommodated are separated in a watertight manner.

  According to the seventh aspect of the present invention, the inner case is accommodated in the inner case accommodating space in a state in which the watertight packing is disposed in the step portion of the inner peripheral surface of the inner case accommodating space, and the inner pressure receiving plate pressing ring is used to When the pressure receiving plate that closes the upper end opening of the case is pressed, the watertight packing is formed on the inner peripheral surface of the inner case housing space and the outer peripheral surface of the inner case, and is a portion inclined with respect to the rotational axis of the impeller By compressing in the up and down direction by each stepped portion having the above, the interior of the lower case is separated from the upstream chamber and the downstream chamber by the watertight packing while maintaining the watertightness.

  According to the first aspect of the present invention, since the inner case accommodation space provided in the lower case can be circular in cross section over the entire height, the shape of the inner case accommodation space provided in the case main body portion of the lower case is simple. Correspondingly, the shape of the entire inner case is simplified as a cylindrical shape, and the watertightness of the watertight packing that separates the lower case into the upstream side and the downstream side is improved, and the double box type Design and manufacture of the lower case and the inner case constituting the water meter become easy.

  According to the third and sixth aspects of the present invention, in the middle of accommodating the inner case in the inner case accommodating space of the lower case, a temporary space between the lower end surface of the upper peripheral wall segment and the upper end surface of the lower peripheral segment is provided. No compressive force is applied to the watertight packing disposed in the packing receiving groove, and a predetermined gap is formed between the packing and the inner peripheral surface of the inner case receiving space. The inner case can be smoothly accommodated in the accommodation space. When the pressure receiving plate covering the upper end opening of the inner case is pressed by the pressure receiving plate pressing ring after the inner case is accommodated, the width of the temporary packing accommodating groove for accommodating the watertight packing (the dimension in the height direction) Is narrowed and a regular packing housing groove is formed, so that the watertight packing bulges outward in the radial direction of the inner case and closely contacts the inner peripheral surface of the inner case housing space of the lower case. Watertightness is achieved.

FIG. 4 is a perspective view of a state where an inner case C ₁ is accommodated in a lower case G. It is a longitudinal cross-sectional view (cross-sectional view along the direction through which tap water flows) of the double box type water meter which concerns on this invention. It is a disassembled perspective view of the double box type water meter which concerns on this invention. It is a perspective view of the separation state of upper and lower case division bodies C ₁ a and C ₁ b constituting the inner case C ₁ . Each case divided body C ₁ a of the upper and lower, is an exploded perspective view showing the positioning structure along a circumferential direction of the C ₁ b. It is a front view of the separation state of upper and lower case division bodies C ₁ a and C ₁ b. Is a cross-sectional view of the middle housing the inner case C ₁ with respect to the inner case accommodating space V ₁ of the lower case G. FIG. 6 is a schematic plan view showing a positioning structure in the circumferential direction of the inner case C ₁ with respect to the inner case accommodation space V ₁ of the lower case G. FIG. 6 is a partially enlarged cross-sectional view of a square packing housing groove 35. Whole is a cross-sectional view of a multi-chamber type water meter which bisected inner case C ₁ structure 'is accommodated in the inner case housing space V ₁ having a packing receiving groove 36 of the non-oval. It is a schematic longitudinal sectional view of a multi-chamber type water meter with an inner casing C ₂ monolithic. A schematic longitudinal sectional view of a multi-box water meter having a structure in which the watertight packing P ₁ is compressed by the elliptical step portions 61 and 62 on the inner peripheral surface of the inner case housing space V _{3 and} the outer peripheral surface of the inner case C ₃ . It is.

First, with reference to FIG. 1 to FIG. 4 and FIG. 7, a method for assembling the double box type water meter which is an embodiment of the invention of claims 3 to 6 and its inner case C ₁ will be described in detail. The lower case G is formed integrally with a cylindrical case main body 41 having an open upper surface with an inlet pipe 42 and an outlet pipe 43 having the same axial center, and the inner space of the case main body 41 is accommodated in an inner case. It has become a space V _1. As shown in FIG. 7, the case body 41 is integrally formed with an annular wall 44 in a state of protruding upward from the inlet pipe 42 and the outlet pipe 43, and inside the annular wall 44, the flange portion 14a of the pressure receiving plate 14 which will be described later, and each of the first and second stepped portions 45 and 46 for arranging the watertight packing P ₂ which holds the watertight between the flange portion 14a is provided, the annular A female screw 47 for screwing a pressure receiving plate pressing ring 22 described later is formed in a portion of the inner peripheral surface of the flange portion 44 above the stepped portions 45 and 46.

As shown in FIGS. 3-7, the peripheral wall body 1 of the inner case C ₁ is the elliptical surface inclined with respect to a rotation axis of the impeller W which is rotatably disposed inside of the inner case C ₁ An upstream chamber U that is divided into upper and lower parts and accommodates unmeasured tap water inside the lower case G by the lower end surface 3a of the upper peripheral wall segment 3 and the upper end surface 4a of the lower peripheral wall segment 4; elliptical packing accommodating groove for accommodating the watertight packing P ₁ for separating the downstream side chamber L metering already tap water is accommodated 5 (see FIG. 2) is formed. In the state where the watertight packing P ₁ is compressed and deformed, the packing housing groove 5 has an isosceles triangle shape that expands toward the outer peripheral surface of the inner case C ₁ . As described above, since the peripheral wall body 1 of the inner case C ₁ is divided into two parts vertically, the inner case C ₁ is vertically is bisected, and below each casing divided body C ₁ a, C ₁ It is constructed by assembling b together.

An inflow port 6 disposed in the upstream chamber U is formed at a portion where the height of the lower peripheral wall segment 4 of the lower case segment C ₁ b is the highest, and a lower surface is formed inside the lower peripheral wall segment 4. The closed bottomed cylindrical nozzle forming body 7 is formed integrally with the axis of the inner case C ₁ (same as the rotational axis of the impeller W), and is formed substantially integrally with the nozzle forming body 7. A plurality of inflow nozzles 8 are formed in the part at regular intervals along the circumferential direction. On the inner side of the lower peripheral wall segment 4, a mating auxiliary pedestal portion 9 having an outer diameter equal to the inner diameter of the peripheral wall body 1 and having a pedestal shape is fully extended to a predetermined height of the lower peripheral wall segment 4. The lower part and the higher part formed over the circumference and lower than the upper surface of the fitting auxiliary pedestal 9 are approximately half and higher on the lower side of the elliptical upper end surface 4a of the lower peripheral wall segment 4 respectively. Almost half of the side is formed. That is, the elliptical upper end surface 4 a of the lower peripheral wall segment 4 is arranged so as to intersect with the upper surface 9 a of the auxiliary mating base 9. In the plan view, the upper and lower peripheral wall segments 3 and 4 can be fitted over the entire circumference of the upper half of the upper end surface 4a of the lower peripheral wall segment 4 having an elliptical shape so that it can be fitted over the entire circumference. An arcuate auxiliary fitting plate portion 11 projects upward. The auxiliary mating base 9 and the auxiliary mating plate 11 are continuous along the circumferential direction.

  A plurality (three in the embodiment) of outflow nozzles 12 are formed at regular intervals along the circumferential direction in a portion above the upper surface 9a of the auxiliary mating base portion 9 in the bottomed cylindrical nozzle forming body 7. A pair of outflow guide plates 13 for guiding the outflow water flow is provided at a portion facing the outflow nozzle 12 on the outer peripheral surface of the nozzle formation body 7 in the tangential direction of the bottomed cylindrical nozzle formation body 7. It is formed to be inclined with respect to.

The upper case divided body C ₁ a is formed integrally with the upper peripheral wall body divided body 3 in such a manner that the pressure receiving plate 14 protrudes like a bowl in the radial direction, and the lower end surface 3a of the upper peripheral wall divided body 3 has an elliptical shape. Is formed. When the upper and lower case division bodies C ₁ a and C ₁ b are assembled together to form the inner case C ₁ , a portion (in the circumferential direction) opposite to the inlet 6 formed in the lower peripheral wall division body 4. A circular outlet 15 is formed in a portion where the phase is 180 °.

As shown in FIG. 5, the upper and lower case division bodies C ₁ a and C ₂ b are positioned in the circumferential direction when the case division bodies C ₁ a and C ₁ b are assembled together. Positioning protrusions 16 and positioning grooves 17 are provided. The positioning protrusion 16 is provided on the back surface of the pressure receiving plate 14 of the upper case divided body C ₁ a, and the positioning groove 17 is formed to open on the upper surface of the upper end portion of the nozzle forming body 7.

As shown in FIGS. 2 and 4, the center of the bottomed cylindrical-shaped bottom plate portion 7a of the nozzle forming body 7 is fixed rotation support shaft 18 becomes a vertical vanes located within the inner casing C ₁ The rotation shaft portion 19 of the vehicle W is rotatably supported by the rotation support shaft 18.

As shown in FIGS. 2 and 6, the end surfaces 3 a and 4 a of the upper and lower peripheral wall divided bodies 3 and 4 are assembled to the upper and lower peripheral walls by assembling the case divided bodies C ₁ a and C ₁ b. each end surface 3a of the body split members 3 and 4, the gasket receiving groove 5 formed by 4a, and is shaped to have a cross-sectional isosceles triangle which is expanded radially outwardly of the inner case C _1. That is, the end surfaces 3a and 4a of the upper and lower peripheral wall divided bodies 3 and 4 have the same angle (θ) with respect to the elliptical surface 21 (see FIG. 6) that bisects the peripheral wall 1 over the entire circumference. It is inclined only [see FIG. 2].

As shown in FIG. 2 and FIGS. 5 to 7, the watertight packing P ₁ is arranged on the upper end surface 4 a of the lower case divided body C ₁ b, and is separately provided on the lower surface of the pressure receiving plate 14 of the upper case divided body C ₁ a. The watertight packing P ₂ is arranged, and the positioning projections 16 and the positioning grooves 17 position the upper and lower case division bodies C ₁ a and C ₁ b in the circumferential direction to fit the lower case division body C ₁ b. When the upper peripheral wall part 3 of the upper case split body C ₁ a is fitted to the outside of the joint auxiliary base part 9 and the fitting auxiliary plate part 11, the end faces 3 a of the upper and lower peripheral wall part splits 3, 4 are arranged. The upper and lower case division bodies C ₁ a and C ₁ b are temporarily assembled in a form in which the watertight packing P ₁ is arranged in the trapezoidal-shaped temporary packing receiving groove 5 ′ (see FIG. 7) between 4 a. , the inner case C _1.

When the temporarily assembled inner case C ₁ is accommodated in the inner case accommodating space V ₁ of the case main body 41, as shown in FIG. 7, the outer peripheral surface of the inner case C ₁ related to temporary assembly. Since no external force is acting on the watertight packing P ₁ accommodated in the elliptical temporary packing accommodating groove 5 ′, the cross section thereof retains the original circular shape. Therefore, since a slight gap K is formed between the watertight packing P ₁ and the inner peripheral surface V ₁ a of the inner case housing space V ₁ , there is no sliding resistance between them. . Therefore, the temporarily assembled inner case C ₁ can be smoothly accommodated in the inner case accommodating space V ₁ .

Thus, the cross-sectional shape of the inner case housing space V ₁ provided in the case main body 41 of the lower case G is a circular shape over the entire height, and has a simple shape with no irregularities on the inner peripheral surface, Correspondingly, the overall shape of the inner case C ₁ is also cylindrical and has a simple shape with no irregularities on the outer peripheral surface, so that the lower case G and the inner case C ₁ can be easily designed and manufactured.

Thereafter, the pressure receiving plate pressing ring 22 is screwed into the female thread 47 on the inner peripheral surface of the annular wall 44 of the case main body 41 of the lower case G, so that the pressure receiving plate 14 of the upper case divided body C ₁ a is When pressed, as shown in detail in the enlarged partial view of the main part of FIG. 2, each of the upper and lower peripheral wall segments 3, 4 constituting the upper and lower case segments C ₁ a, C ₁ b When the inner peripheral portions of the end surfaces 3a and 4a are close to each other, the end surfaces 3a and 4a make the temporary packing housing groove 5 'having a trapezoidal cross section become the original packing housing groove 5 having an isosceles triangular cross section. . Therefore, the watertight packing P ₁ disposed in the temporary packing housing groove 5 ′ between the end faces 3 a and 4 a which are separated from each other is compressed and deformed and bulges outward in the radial direction of the inner case C _1. The inner case housing space V ₁ is in close contact with the inner peripheral surface V ₁ a. As a result, the interior of the lower case G is divided into the upstream chamber U and the downstream chamber L by the watertight packing P ₁ that is compressed and deformed and is in close contact with the inner peripheral surface V ₁ a of the inner case housing space V ₁ in an elliptical shape. The portion where the impeller W inside the inner case C ₁ is separated while maintaining watertightness is the measuring chamber R. The positioning in the circumferential direction with respect to the lower case G when the temporarily assembled inner case C ₁ is accommodated in the inner case accommodating space V ₁ is, as shown in FIGS. 2 and 8, the lower case divided body C ₁ b This is done by fitting a positioning pin 23 projecting from the bottom surface of the bottom plate portion 7 a of the nozzle forming body 7 into a positioning hole 24 provided in the bottom plate portion 41 a of the case main body portion 41.

In the above embodiment, since the cross-sectional shape of the packing receiving groove 5 is an isosceles triangle, the ratio of the inner case C ₁ bulging outward in the radial direction is increased during the compression deformation of the watertight packing P ₁ . There is an advantage that water tightness is enhanced. As described above, the optimal shape of the packing receiving groove is a triangular shape, but as shown in FIG. 9, it may be a packing receiving groove 35 having a square cross section.

The tap water flowing in from the inlet pipe 42 flows into the measuring chamber R through the inlet 6 of the inner case C ₁ and the plurality of inflow nozzles 8 along the substantially tangential direction of the blade body 31 of the impeller W. Thus, after the impeller W is rotated, it flows out from the measuring chamber R toward the external outlet pipe 43 through the plurality of outflow nozzles 12 and the outflow ports 15. A connecting magnet 32 is embedded in the upper end portion of the rotating shaft portion 19, and an input shaft (not shown) constituting the integrated flow rate display unit S is arranged immediately above the rotating shaft portion 19 of the impeller W, and In the lower end portion of the input shaft, another connecting magnet (not shown) that constitutes a magnet connector in cooperation with the connecting magnet 32 is embedded, and the rotation of the impeller W is directly transmitted to the input shaft. Thus, the integrated flow rate display unit S displays the integrated flow rate of tap water passing through the measuring chamber R. In FIG. 2, reference numeral 33 denotes an entire cover that covers an outer case (not shown) in which the integrated flow rate display unit S is incorporated.

The double box type water meter of the above embodiment has a configuration in which the inner case C ₁ is divided into two vertically by an elliptical surface inclined with respect to the rotational axis of the impeller W, and the entire watertight packing P ₁ is elliptical. Since the curved state of the water-tight packing P ₁ gradually changes over the entire circumference and there is no portion that changes suddenly, an excessive force is exerted on the water-tight packing P _1. Does not act, and there is an advantage that high water tightness can be maintained over a long period of time.

However, according to the present invention, the interior of the lower case G is separated from the upstream side chamber U and the downstream side chamber by the watertight packing P ₁ that maintains the water tightness between the outer peripheral surface of the inner case C ₁ and the inner peripheral surface of the inner case accommodation space V _1. Since the essence exists in the separation into L, the arrangement of the watertight packing P ₁ is not limited to the elliptical surface inclined with respect to the rotation axis of the impeller W. That is, each shape of the packing accommodating groove 36 and the watertight packing P ₁ ′ accommodated in the packing accommodating groove 36 has upper ends close to the inlet 6 and the outlet 15 in the watertight packing P ₁ ′, as shown in FIG. The portion and the lower end are respectively arranged in a plane inclined with respect to the rotational axis of the impeller W, and the portions other than the upper end and the lower end are in a plane perpendicular to the rotational axis of the impeller W. The shape may be arranged horizontally. The advantage of having such a shape is to facilitate the arrangement of the inflow nozzle and the outflow nozzle provided in the inner case C ₁ ′. The arrangement structure of the packing P ₁ ′ described above can be applied to both the upper and lower divided type and the integral type inner case.

The above-described embodiments according to the third to sixth aspects of the present invention have a configuration in which the inner case C ₁ is vertically divided into two on the elliptical surface inclined with respect to the rotational axis of the impeller W. , as shown in FIG. 11, elliptical packing accommodating groove 51 is formed at a portion intersecting the inclined elliptical surface with respect to a rotation axis of the impeller W on the outer peripheral surface of the inner case C ₂ monolithic The inner case C ₂ is pushed into the inner case accommodating space V ₁ of the case main body 41 and accommodated in a state where the watertight packing P ₁ is compressed and accommodated in the packing accommodating groove 51.

In a state where the watertight packing P ₁ is compressed and deformed in the packing receiving groove 51 on the outer peripheral surface of the inner case C ₂ , the compressed and deformed packing P ₁ protrudes from the outer peripheral surface of the inner case C _{2 and} is stored. in close contact with the inner peripheral surface of the inner case accommodating space V ₂ after the middle and housed. Therefore, in order to reduce the resistance of the portion of the watertight packing P ₁ at the time of pushing accommodating the inner case C ₂ against the inner casing accommodating space V _2, when applying the lubricating oil or the like to the inner circumferential surface of the inner case housing space V ₂ The inner case C ₂ can be pushed and accommodated smoothly.

FIG. 12 is a longitudinal sectional view of the double box type water meter of the embodiment of the invention of claim 7, and corresponds to the inner peripheral surface of the inner case housing space V _{3 and} the outer peripheral surface of the inner case C ₃ , respectively. Oval step portions 61 and 62 are provided. The oval shaped step portion 61 of the inner peripheral surface of the inner case housing space V ₃ in the state in which the watertight packing P _1, accommodates the inner case C ₃ to the inner case housing space V _3, the pressure receiving plate retainer ring 22 By pressing the pressure receiving plate 14 ′ that closes the upper end opening of the inner case C ₃ , the watertight packing P ₁ is formed on the inner peripheral surface of the inner case accommodating space V ₃ and the outer peripheral surface of the inner case C _3. By being compressed in the vertical direction by the respective stepped portions 61 and 62, the inside of the lower case G ′ is separated from the upstream chamber U and the downstream chamber L by the watertight packing P ₁ while maintaining watertightness. . 10 to 12, the same or equivalent parts as those in the embodiments of the inventions of claims 3 to 6 are indicated by the same reference numerals or the same reference signs with “′”.

In each of the above-described embodiments, the peripheral wall body 1 is formed over the entire height of the inner cases C _{1 to} C ₃ , and the inflow and outflow nozzles 8 and 12 are both inside the peripheral wall body 1. Although an arrangement has been constructed, in the present invention, only necessary I peripheral wall member is provided at least on placement of the watertight packing P _1, one or both either inflow and the nozzles 8, 12 of the outflow, It may be an exposed configuration without being arranged inside the wall. In particular, by exposing the inflow nozzle 8 side, the pressure loss of the inflowing water flow is reduced, and an improvement in instrumental performance can be expected.

C ₁ ~C _3: inner case
C ₁ a: Upper case division
C ₁ b: Lower case divided body
G: Lower case
K: Clearance between the watertight packing and the inner peripheral surface of the inner case housing space
L: Downstream chamber
P ₁ : Watertight packing to be fitted into the packing receiving groove of the inner case
P ₂ : Water-tight packing that keeps the pressure-receiving plate portion water-tight
R: Weighing room
U: upstream side chamber V ₁ ~V _3: inner case accommodating space
1: Perimeter wall
3: Upper peripheral wall segment
4: Lower peripheral wall divided body 5, 35, 36: Packing accommodating groove
5 ': Temporary packing receiving groove
8: Inflow nozzle
12: Outflow nozzle
14: Pressure plate
41: Case main body 61, 62: Stepped portion

Claims (7)

An inner case housing space is formed in the case main body portion between the inlet pipe and the outlet pipe formed in the lower case with the same axis, and the inner case has a measuring chamber formed therein to allow inflow and outflow. A double box water meter with a configuration in which each nozzle is formed,
On the outer peripheral surface of the inner case, a packing housing groove having a portion inclined with respect to the rotational axis of the impeller disposed in the measuring chamber is formed,
By being accommodated in the packing accommodating groove, the interior of the lower case is upstream of an unmetered tap water accommodated by a watertight packing having a portion that is partially inclined with respect to the rotational axis of the impeller. A double box type water meter characterized in that the side chamber and the downstream side chamber in which measured tap water is accommodated are separated in a watertight manner.   The packing housing groove formed on the outer peripheral surface of the inner case is elliptical, and the whole of the watertight packing is disposed on an elliptical surface inclined with respect to the rotational axis of the impeller. The double box type water meter according to claim 1.   The peripheral wall of the inner case is vertically divided into two parts in the packing housing groove, and the upper and lower peripheral wall bodies are assembled to each other so that the inner case is accommodated in the inner case housing space. By compressing the watertight packing accommodated in the packing accommodation groove formed between the lower end surface and the upper end surface of the lower peripheral wall divided body from above, the watertight packing is expanded radially outward of the peripheral wall body. The double box type water meter according to claim 1 or 2, wherein the double box type water meter is configured to be deformed and brought into close contact with an inner peripheral surface of the inner case accommodation space.   4. The double box water meter according to claim 3, wherein a cross section of the packing receiving groove has a triangular shape that expands toward the outer peripheral surface of the inner case.   A pressure receiving plate portion that is in close contact with a step portion formed at the upper end portion of the inner case housing space via a watertight packing is integrally formed at the upper end portion of the upper peripheral wall divided body. Item 5. The double box type water meter according to item 3 or 4. A method for housing and assembling the inner case of the double box type water meter according to claim 3 in the inner case housing space of the lower case,
Temporary assembly in which watertight packing is disposed in a non-compressed state in a temporary packing housing groove between the lower end surface of the upper peripheral wall segment and the upper end surface of the lower peripheral wall segment by temporarily assembling the upper and lower peripheral wall segments After the inner case is accommodated in the inner case accommodating space, the pressure-receiving plate is pressed downward by the pressure-receiving plate retaining ring, so that the watertight packing is bulged and deformed outward in the radial direction of the inner case, and the inner case is accommodated. A method for assembling an inner case of a double box water meter, wherein the inner case is brought into close contact with the inner peripheral surface of the space. An inner case housing space having a circular cross section is formed in the case main body between the inlet pipe and the outlet pipe formed in the lower case with the same axis, and the inner case has a measuring chamber formed therein. A double box water meter having a structure in which each of the inflow and outflow nozzles is formed,
The inner peripheral part of the inner case housing space of the case main body part and the outer peripheral part of the inner case have portions inclined with respect to the rotation axis of the impeller that is rotatably arranged in the measuring chamber. , Step portions corresponding to each other are formed,
The inside of the lower case is unmetered by the watertight packing having a portion that is partially inclined with respect to the rotational axis of the impeller by being accommodated in the packing accommodating groove between the step portions. A double box type water meter characterized in that an upstream chamber in which water is stored and a downstream chamber in which metered tap water is stored are separated in a watertight manner.

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