JP7535935B2 - Meter joint structure - Google Patents

Description

The present invention relates to a meter joint structure that connects between a meter inlet portion, which is a portion of a meter flow end through which gas flows into and out of a gas meter that measures the flow rate of gas flowing through a gas pipe, and a gas pipe outlet portion, which is the end of the gas pipe on the primary side of the gas pipe, and between a meter outlet portion, which is a portion of the meter flow end through which gas flows out, and a gas pipe inlet portion, which is the end of the gas pipe on the secondary side of the gas pipe.

A union-type pipe fitting is known as a pipe fitting that connects a gas pipe end of a gas piping system to a meter flow end, which is a meter inlet portion and a meter outlet portion of a gas meter, without any relative rotation between the two (see Patent Document 1).
The union type pipe fitting is composed of a union nut that is prevented from coming loose by a union flange that extends radially outward from the outer periphery of the gas pipe end, and a union screw that is provided at the meter flow end and into which the union nut can be screwed.
When the gas meter's inspection deadline has come, the gas meter is removed from the gas piping system by releasing the union nut from the union screw, and the meter is replaced by screwing the union screw provided at the gas flow end of a new gas meter into the union nut.

JP 2006-9951 A

Recently, as gas meters are becoming smart meters, they are being gradually replaced with gas meters with housing shapes that are different from the conventional ones. However, depending on the location where the gas meter is installed, a block wall or the like is provided in front of the gas meter, and in some places, the block wall has an opening only in the part facing the meter display unit that displays the flow rate, etc. measured by the gas meter.
If a gas meter with a different housing shape is installed in such a location, the meter display of the new gas meter may be misaligned with the opening in the block wall, which may make it difficult to properly view the meter display.

The present invention was made in consideration of the above-mentioned problems, and its purpose is to provide a meter joint structure that can set the up and down positions of the meter display unit on the gas meter to be approximately the same before and after replacement, even if a gas meter with a different housing shape is connected before and after the replacement of the gas meter, and that can prevent co-rotation during installation, improving workability.

The meter joint structure for achieving the above object is as follows:
A meter joint structure is provided between a meter inlet portion, which is a portion of a meter flow end through which gas flows into and out of a gas meter that measures the flow rate of gas flowing through a gas pipe, and a gas pipe outlet portion, which is a gas pipe end of a primary gas pipe, and between a meter outlet portion, which is a portion of the meter flow end through which gas flows out, and a gas pipe inlet portion, which is a gas pipe end of a secondary gas pipe, and the structure is characterized by the following:
The gas pipe outlet portion and the gas pipe inlet portion are each provided with a union nut that is rotatable relative to an end portion of the gas pipe,
Each of the meter inlet portion and the meter outlet portion has a first annular screw portion formed along an outer periphery thereof into which the union nut can be screwed,
a cylindrical body having a second annular screw portion at one end into which the union nut can be screwed, and a coupling nut that can be screwed into the first annular screw portion at the other end, which is inserted so as to be relatively rotatable;
a co-rotation prevention mechanism capable of maintaining a co-rotation prevention state in which the cylindrical main body is prevented from co-rotating with the union nut at least when the union nut is screwed into the second annular screw portion ,
In the co-rotation prevention state, the co-rotation prevention mechanism
a plate-like member interposed between a first cylindrical body as the cylindrical body between the gas pipe outlet portion and the meter inlet portion and a second cylindrical body as the cylindrical body between the gas pipe inlet portion and the meter outlet portion;
a first contact portion formed on an outer circumferential portion of the first cylindrical body and capable of engaging one end of the plate-like member; and a second contact portion formed on an outer circumferential portion of the second cylindrical body and capable of engaging the other end of the plate-like member.
the plate-like member has a flat portion along a transverse direction intersecting a cylindrical axis of the first cylindrical body and a cylindrical axis of the second cylindrical body, and in a body-to-body direction connecting the first cylindrical body and the second cylindrical body, has a pair of first locking claws at one end of the plate-like member which are flat portions and extend in the body-to-body direction, and has a pair of second locking claws at the other end of the plate-like member which are flat portions and extend in the body-to-body direction,
The first cylindrical main body has a pair of first notches as the first abutted portions which abut against each of the pair of first engaging claws in the anti-rotation state, and the second cylindrical main body has a pair of second notches as the second abutted portions which abut against each of the pair of second engaging claws in the anti-rotation state .

According to the above characteristic configuration, each of the meter inlet portion and the meter outlet portion has a first annular screw portion formed along its outer periphery into which a union nut can be screwed, and further has a cylindrical body having a second annular screw portion into which the union nut can be screwed at one end and a coupling nut that can be screwed into the first annular screw portion at the other end, which is inserted so as to be freely rotatable relative to the first annular screw portion. Therefore, by selecting an appropriate length for the cylindrical body, the union nut can be screwed into the second annular screw portion and the coupling nut can be screwed into the first annular screw portion, so that the distance of the meter display portion from the gas pipe light portion can be adjusted to the desired distance, even for gas meters with different housing outer shapes.
Furthermore, the tubular main body is provided with a co-rotation prevention mechanism that can maintain a co-rotation prevention state that prevents the tubular main body from rotating together with the union nut at least when the union nut is screwed into the second annular screw portion.Therefore, it is possible to prevent, for example, the union nut and the tubular main body from rotating together when the union nut is fastened to the second annular screw portion, resulting in insufficient screwing between the union nut and the second annular screw portion.
Furthermore, with the above-mentioned characteristic configuration, in a state in which one end of the plate-like member is engaged with the first abutment portion of the first cylindrical body and the other end is engaged with the second abutment portion of the second cylindrical body, for example, when a force is applied to the first cylindrical body in a rotational direction about the cylindrical axis, a force is also applied to the plate-like member to rotate about the cylindrical axis of the first cylindrical body to which one end is engaged, but since the other end of the plate-like member is engaged with the second cylindrical body, the rotation of the plate-like member is prevented, and as a result, the rotation of the first cylindrical body is also prevented. This makes it possible to prevent the union nut and the cylindrical body from rotating together.
Furthermore, according to the above characteristic configuration, by providing the flat portion of the plate-like member in a state in which it intersects both the cylindrical axis of the first cylindrical body and the cylindrical axis of the second cylindrical body, when a force is applied to either the first cylindrical body or the second cylindrical body around its cylindrical axis, the force component of the torque applied to the plate-like member that is along the plane of the flat portion can be made larger compared to the case in which the flat portion is provided parallel to both, and deformation of the plate-like member can be suppressed.
Furthermore, since a pair of first locking claws of the plate-shaped member contact and abut a pair of first notches of the first cylindrical main body, and a pair of second locking claws of the plate-shaped member contact and abut a pair of second notches of the second cylindrical main body to prevent co-rotation, the first and second notches of the first and second cylindrical main bodies are less likely to come out of the first and second locking claws of the plate-shaped member, and co-rotation can be prevented even more firmly.
As a result, even if a gas meter with a different housing shape is connected before and after the gas meter replacement, the up and down positions of the meter display unit provided on the gas meter can be set to approximately the same before and after the replacement, and a meter coupling structure can be realized that prevents co-rotation during installation, improving ease of construction.

The meter joint structure for achieving the above object is as follows:
A meter joint structure is provided between a meter inlet portion, which is a portion of a meter flow end through which gas flows into and out of a gas meter that measures the flow rate of gas flowing through a gas pipe, and a gas pipe outlet portion, which is a gas pipe end of a primary gas pipe, and between a meter outlet portion, which is a portion of the meter flow end through which gas flows out, and a gas pipe inlet portion, which is a gas pipe end of a secondary gas pipe, and the structure is characterized by the following:
The gas pipe outlet portion and the gas pipe inlet portion are each provided with a union nut that is rotatable relative to an end portion of the gas pipe,
Each of the meter inlet portion and the meter outlet portion has a first annular screw portion formed along an outer periphery thereof into which the union nut can be screwed,
a cylindrical body having a second annular screw portion at one end into which the union nut can be screwed, and a coupling nut that can be screwed into the first annular screw portion at the other end, which is inserted so as to be relatively rotatable;
a co-rotation prevention mechanism capable of maintaining a co-rotation prevention state in which the cylindrical main body is prevented from co-rotating with the union nut at least when the union nut is screwed into the second annular screw portion,
In the co-rotation prevention state, the co-rotation prevention mechanism
a plate-like member interposed between a first cylindrical body as the cylindrical body between the gas pipe outlet portion and the meter inlet portion and a second cylindrical body as the cylindrical body between the gas pipe inlet portion and the meter outlet portion;
a first contact portion formed on an outer circumferential portion of the first cylindrical body and capable of engaging one end of the plate-like member; and a second contact portion formed on an outer circumferential portion of the second cylindrical body and capable of engaging the other end of the plate-like member.
the plate-like member includes a first plate-like member having a first abutment surface that abuts against both a first abutment surface of the first abutment portion and a second abutment surface of the second abutment portion in the co-rotation prevention state, and a second plate-like member having a second abutment surface that abuts against both the first abutment surface and the second abutment surface,
In the anti-rotation state, when the first abutment surface abuts against the first abutted portion and the second abutted portion and the second abutment surface abuts against the first abutted portion and the second abutted portion, a fastening portion is provided which clamps and fastens the first plate-shaped member and the second plate-shaped member.

In particular, according to the above characteristic configuration, the plate-shaped member is composed of a pair of a first plate-shaped member and a second plate-shaped member, and the fastening portion clamps and fastens the first plate-shaped member and the second plate-shaped member while the abutment surfaces of both the first plate-shaped member and the second plate-shaped member abut against the abutted surfaces of the first cylindrical body and the second cylindrical body. Therefore, by reliably fastening the fastening portion, rotation of the first cylindrical body and the second cylindrical body can be prevented, and co-rotation of the cylindrical body can be prevented when the union nut is screwed together.

Further characteristic configurations of the meter joint structure include:
The first abutment surface has a rear side first abutment surface against which the first abutment surface of the first plate-like member abuts, and a front side first abutment surface against which the second abutment surface of the second plate-like member abuts,
The second abutment surface has a rear side second abutment surface against which the first abutment surface of the first plate-shaped member abuts, and a front side second abutment surface against which the second abutment surface of the second plate-shaped member abuts.

In other words, the first plate-like member and the second plate-like member each abut against a different surface of the first abutted surface of the first cylindrical body, and also abut against a different surface of the second abutted surface of the second cylindrical body, thereby realizing a reliable abutment state that avoids mutual interference.

Further characteristic configurations of the meter joint structure include:
the first plate-like member and the second plate-like member are configured to be longer than a distance between the first cylindrical body and the second cylindrical body in a body-to-body direction connecting the first cylindrical body and the second cylindrical body,
a first one-end engaging portion formed at one end of the first plate-like member in the inter-body direction and a second one-end engaging portion formed at one end of the second plate-like member in the inter-body direction are configured to be engageable with each other, and a first other-end engaging portion formed at the other end of the first plate-like member in the inter-body direction and a second other-end engaging portion formed at the other end of the second plate-like member in the inter-body direction are configured to be engageable with each other,
In the anti-rotation state, on the outside between the first cylindrical main body and the second cylindrical main body, the first one-end engaging portion and the second one-end engaging portion engage and the first other-end engaging portion engage with the second other-end engaging portion, and in the region between the first cylindrical main body and the second cylindrical main body, the fastening portion fastens the first plate-like member and the second plate-like member.

According to the above characteristic configuration, the first plate-like member and the second plate-like member as plate-like members are engaged or fastened at three points: an outer position between the bodies of the first and second cylindrical bodies at one end of the plate-like member, an outer position between the bodies of the first and second cylindrical bodies at the other end of the plate-like member, and a position (area) between the bodies of the first and second cylindrical bodies. Therefore, the first plate-like member and the second plate-like member more firmly hold the first and second cylindrical bodies, and can more effectively prevent rotation when a force is applied to either the first or second cylindrical body around its cylindrical axis.

Further characteristic configurations of the meter joint structure include:
The plate-shaped member has a feature that, in the anti-rotation state, when viewed in the cylindrical axis direction along the cylindrical axis of the first cylindrical body and the second cylindrical body, forms an insertion opening between the first cylindrical body and the second cylindrical body through which a part of the casing of the gas meter can be inserted.

Depending on the shape of the housing of the new gas meter, it is also envisaged that the shape will have a part of the gas meter housing protruding between the first cylindrical body and the second cylindrical body, in the direction of the cylindrical axis, toward the gas pipe end side beyond the coupling nut.
According to the above characteristic configuration, even when a plate-shaped member is interposed between the first cylindrical body and the second cylindrical body, the plate-shaped member has an insertion opening between the first cylindrical body and the second cylindrical body through which a part of the gas meter housing can be inserted, so that a part of the gas meter housing can be inserted into the insertion opening to effectively prevent co-rotation.

Further characteristic configurations of the meter joint structure include:
The plate-like member has a through hole at the center of the first cylindrical body and the second cylindrical body in the inter-body direction in the anti-rotation state, which penetrates in a direction intersecting both the cylindrical axis of the first cylindrical body and the second cylindrical body and the inter-body direction.

According to the above characteristic configuration, the handle that supports the gas meter can be attached to the plate-shaped member by inserting it into the through hole. Therefore, even if the handle provided on the gas meter body becomes unusable due to the installation of the meter coupling mechanism, the handle can be attached to the plate-shaped member and the gas meter can be easily supported by hand.

The characteristic configuration of the meter joint structure for achieving the above object is as follows:
A meter joint structure is provided between a meter inlet portion, which is a portion of a meter flow end through which gas flows into and out of a gas meter that measures the flow rate of gas flowing through a gas pipe, and a gas pipe outlet portion, which is a gas pipe end of a primary gas pipe, and between a meter outlet portion, which is a portion of the meter flow end through which gas flows out, and a gas pipe inlet portion, which is a gas pipe end of a secondary gas pipe, and the structure is characterized by the following:
The gas pipe outlet portion and the gas pipe inlet portion are each provided with a union nut that is rotatable relative to an end portion of the gas pipe,
Each of the meter inlet portion and the meter outlet portion has a first annular screw portion formed along an outer periphery thereof into which the union nut can be screwed,
a cylindrical body having a second annular screw portion at one end into which the union nut can be screwed, and a coupling nut that can be screwed into the first annular screw portion at the other end, which is inserted so as to be relatively rotatable;
a co-rotation prevention mechanism capable of maintaining a co-rotation prevention state in which the cylindrical main body is prevented from co-rotating with the union nut at least when the union nut is screwed into the second annular screw portion,
The cylindrical main body includes a third chamfered portion formed by chamfering an outer circumferential portion of the cylindrical main body along a cylindrical axis direction,
The joint nut includes a body side end surface formed on the body side of the cylindrical body, and a fourth chamfered portion formed by chamfering an outer circumferential portion along the cylindrical axis direction,
The co-rotation prevention mechanism is
a cylindrical body outer fitting member that is fitted onto an outer circumferential portion of the cylindrical body, is slidable along the cylindrical axial direction, and has a first flat portion that can abut against the third chamfered portion, and is in a first fitting position in which relative rotation with respect to the cylindrical body is prohibited when the first flat portion abuts against the third chamfered portion;
a fastening portion for positioning the cylindrical main body outer fitting member relative to the cylindrical main body in the cylindrical axial direction;
a coupling nut cover member having a second flat portion capable of contacting the body side end face of the coupling nut and a third flat portion capable of contacting the fourth chamfered portion of the coupling nut, the body side end face and the second flat portion being in contact with each other and the fourth chamfered portion and the third flat portion being in contact with each other, and the coupling nut cover member is fitted onto the coupling nut in a second externally fitted position in which relative rotation with respect to the coupling nut about the cylindrical axis is prohibited;
In the anti-rotation state, the cylindrical main body outer fitting member is in the first outer fitting position and the joint nut cover member is in the second outer fitting position, and the fastening portion positions the cylindrical main body outer fitting member in the direction of the cylindrical axis, and has a relative rotation prohibition portion that prohibits relative rotation between the cylindrical main body outer fitting member and the joint nut cover member in the screwing and tightening direction of the union nut.

In particular, according to the above characteristic configuration, when in the anti-rotation state, the cylindrical main body outer fitting member is in the first outer fitting position and the coupling nut cover member is in the second outer fitting position, and the fastening portion positions the cylindrical main body outer fitting member in the cylindrical axial direction, the relative rotation prohibition portion prohibits relative rotation between the cylindrical main body outer fitting member and the coupling nut cover member in the screwing and tightening direction of the union nut.Therefore, for example, when the coupling nut is sufficiently screwed into the first annular screw portion, it is possible to prevent the cylindrical main body from rotating together with the union nut in the screwing and tightening direction when the union nut is tightened in the screwing and tightening direction.

1 is a schematic configuration diagram of a gas meter including a meter joint structure according to a first embodiment; FIG. 2 is a side view of the meter joint structure according to the first embodiment. FIG. 2 is a plan view of the meter joint structure according to the first embodiment as viewed in the direction of a cylinder axis. 13A and 13B are a plan view and a side view as viewed in a cylinder axis direction of a meter joint structure according to a second embodiment. 13A and 13B are diagrams illustrating a cylindrical body outer fitting member and a fastening portion of a meter joint structure according to a third embodiment. FIG. 13 is a diagram showing a joint nut cover member of the meter joint structure according to the third embodiment. FIG. 13 is a diagram showing a co-rotation prevention state of the meter joint structure according to the third embodiment. 6A and 6B are a plan view and a side view as viewed in the cylinder axis direction of a meter joint structure according to another embodiment. 6A and 6B are a plan view and a side view as viewed in the cylinder axis direction of a meter joint structure according to another embodiment. FIG. 11 is a schematic configuration diagram of a meter joint structure according to another embodiment.

The meter joint structure 100 according to an embodiment of the present invention is capable of setting the up and down positions of the meter display unit provided on the gas meter to be approximately the same before and after replacement, even if a gas meter 10 with a different housing shape is connected before and after replacement of the gas meter 10, and is capable of preventing co-rotation during installation, thereby improving ease of construction.
The meter joint structure 100 is intended to be operated, for example, when replacing a gas meter 10 that has reached the end of its inspection period. Therefore, first, the gas meter 10 and its associated gas piping system will be described below with reference to the drawings, and then the meter joint structure 100 will be described.

[Gas meter 10 and gas piping system]
As shown in Fig. 1, a gas piping system for supplying gas such as city gas from a primary side operated by a gas supplier as a gas supply source is equipped with a gas meter 10 for measuring the flow rate of gas supplied to a consumer side. A gas pipe as the gas piping system is installed in a form in which a pair of standpipes 1 and 7 extend upward from the ground or the like. In this embodiment, the standpipe 1 corresponds to the primary gas piping, and the standpipe 7 corresponds to the secondary gas piping.

A pair of elbows 2, 6 are attached to the upper ends of the pair of standpipes 1, 7, respectively, and each elbow 2, 6 has a piping side connection portion 2a, 6a formed therein that faces a pair of meter flow ends 43, 44 provided on a gas meter 10, the details of which will be described later.
The pair of piping side connection parts 2a, 6a are formed as a pair of openings that open downward at the ends of the elbows 2, 6 opposite to the ends connected to the risers 1, 7.
A meter gas valve 2b is provided on the primary side standpipe 1. By operating this meter gas valve 2b, the supply of gas from the primary side through the gas meter 10 to the secondary side can be turned on and off.

The gas meter 10 has a similar structure to known gas meters and therefore a detailed description thereof will be omitted, but has a pair of meter flow ends 43, 44 that open opposite the above-mentioned pipe side connections 2a, 6a, and is configured to measure the flow rate of gas by causing gas that flows in from the meter inlet 43 of the pair of meter flow ends 43, 44 to flow out from the meter outlet 44. The pair of meter flow ends 43, 44 are provided on the upper surface of the gas meter 10, and are formed as a pair of openings that open upward.
Incidentally, a meter display unit H that displays the gas flow rate and the like measured by the gas meter 10 is provided on the front surface of the housing 10a of the gas meter 10 (the tip side of the arrow Y in Figure 1), and is visible from the outside.

A pair of piping side connectors 2a, 6a, which are provided in the above-mentioned gas piping system and open downward, have male threads formed on one end (upper end) of the pipes 3, 4, which are screwed into female threads formed on the piping side connectors 2a, 6a, with a liquid sealant or the like applied thereto. A bracket 40 for supporting the gas meter 10 is fixed by nuts 41, 42.
The other ends (lower ends) of the pipes 3, 4 are provided with stop rings (not shown) that prevent the union nuts 8a, 9a inserted into the pipes 3, 4 from coming loose, and the other ends (lower ends) of the pipes 3, 4 function as the gas pipe outlet portion 3a and the gas pipe inlet portion 4a as the gas pipe end portions 3a, 4a.
Incidentally, the union nuts 8a, 9a are components that constitute a union type pipe joint that can connect the gas pipe ends 3a, 4a and the meter flow ends 43, 44 without rotating them relative to each other. However, in this embodiment, the gas pipe ends 3a, 4a and the meter flow ends 43, 44 are connected using a meter joint structure 100 described later instead of the union type pipe joint.

As described above, the gas meter 10 is provided with a meter display unit H on the front surface of the housing 10a, which enables the gas flow rate and the like measured from outside to be visually confirmed. However, in a state in which a retaining wall (not shown) is erected in which an opening (not shown) through which the meter display unit H is visually confirmed is provided only on the front surface of the meter display unit H of the gas meter 10, if a gas meter 10 with a housing shape that differs before and after the replacement of the gas meter 10 is connected, the vertical position of the meter display unit H may be misaligned with the opening in the retaining wall before and after the replacement of the gas meter 10.
The meter joint structure 100 according to an embodiment of the present invention enables the upper and lower positions of the meter display unit H provided on the gas meter 10 to be set to approximately the same before and after replacement, and has the following configuration to prevent co-rotation with the union nuts 8a, 9a during installation, thereby improving ease of installation.

As shown in FIGS. 1 to 3 , the meter coupling structure 100 according to the first embodiment is provided with a union pipe coupling into which first annular screw portions 43a, 44a can be screwed, which are provided at meter flow ends 43, 44 into which union nuts 8a, 9a that are rotatable relative to gas pipe ends 3a, 4a can be screwed, and is equipped with cylindrical bodies 12, 22 having second annular screw portions 11, 21 into which the union nuts 8a, 9a can be screwed at one end and into which coupling nuts 13, 23 that can be screwed onto the first annular screw portions 43a, 44a are inserted so as to be rotatable relative to the other end, and a co-rotation prevention mechanism 30 that can maintain a co-rotation prevention state that prevents the cylindrical bodies 12, 22 from co-rotating with the union nuts 8a, 9a at least when the union nuts 8a, 9a are screwed onto the second annular screw portions 11, 21.
Incidentally, the joint nut 13 is prevented from coming off by a first stop ring 14 that fits into the cutout groove 12f of the first cylindrical body 12, and the joint nut 23 is prevented from coming off by a second stop ring 24 that fits into the cutout groove 22f of the second cylindrical body 22.

As shown in Figs. 1 to 3, the co-rotation prevention mechanism 30, in the co-rotation prevention state, is composed of a plate-like member 34 interposed between the first cylindrical body 12 as the cylindrical body 12, 22 between the gas pipe outlet 3a and the meter inlet 43 and the second cylindrical body 22 as the cylindrical body 12, 22 between the gas pipe inlet 4a and the meter outlet 44, a first chamfered portion 12b (an example of a first abutted portion) formed by chamfering the outer peripheral portion along the cylindrical axis direction (arrow Z direction) of the first cylindrical body 12 and with which one end of the plate-like member 34 can be engaged, and a second chamfered portion 22b (an example of a second abutted portion) formed by chamfering the outer peripheral portion along the cylindrical axis direction (arrow Z direction) of the second cylindrical body 22 and with which the other end of the plate-like member 34 can be engaged.

To explain further, the plate-like member 34 is composed of a planar plate member having a planar portion 34a along a transverse direction (in this embodiment, a direction perpendicular to the cylindrical axes P1, P2) that intersects the cylindrical axis P1 of the first cylindrical body 12 and the cylindrical axis P1 of the second cylindrical body 22, and in the inter-body direction (arrow X direction) connecting the first cylindrical body 12 and the second cylindrical body 22, the plate-like member 34 has at one end a pair of first locking claws 31 that are planar portions and extend in the inter-body direction, and the plate-like member 34 has at the other end a pair of second locking claws 32 that are planar portions and extend in the inter-body direction.
In other words, when viewed in a planar view that is perpendicular to the planar portion 34a shown in Figure 3, a pair of first locking claws 31 are formed at one end of the plate-shaped member 34 by cutting out a portion of approximately the center of the planar portion 34a in a planar view, and a pair of second locking claws 32 are formed at the other end of the plate-shaped member 34 by cutting out a portion of approximately the center of the planar portion 34a in a planar view.

On the other hand, the first cylindrical body 12 has a pair of first notches as first abutted portions (first chamfered portions 12b) that face and abut against the pair of first locking claws 31 in the anti-rotation state, and the second cylindrical body 22 has a pair of second notches as second abutted portions (second chamfered portions 22b) that face and abut against the pair of second locking claws 32 in the anti-rotation state. Note that the portion of the first notches that faces and abuts against the first locking claws 31 and the portion of the second notches that faces and abuts against the second locking claws 32 may be line segments.

With the above configuration, when the union nuts 8a, 9a are fastened by screwing the second annular screw portions 11, 21 together, co-rotation of the first cylindrical body 12 and the second cylindrical body 22 on which the second annular screw portions 11, 21 are provided can be prevented in conjunction with the rotation of the union nuts 8a, 9a.

As shown in Figures 1 to 3, when in a rotation prevention state, the plate-like member 34 has a through hole 33a that penetrates in a direction intersecting both the cylindrical axes P1, P2 of the first cylindrical body 12 and the second cylindrical body 22 and the inter-body direction (arrow X direction) at the center portion (a position equidistant from both) of the first cylindrical body 12 and the second cylindrical body 22 in the inter-body direction (arrow X direction) between the first cylindrical body 12 and the second cylindrical body 22.
To provide further explanation, particularly as shown in Figures 2 and 3, in a state in which co-rotation is prevented, the plate-like member 34 has a pair of trapezoidal plate portions 33 welded to the central portions (positions equidistant from both) of the first cylindrical body 12 and the second cylindrical body 22 in the inter-body direction (arrow X direction) between the first cylindrical body 12 and the second cylindrical body 22, with the pair of trapezoidal plate portions 33 having a plane perpendicular to the planar direction of the planar portion 34a, and a through hole 33a is formed in each of the pair of trapezoidal plate portions 33.
By inserting an end of a handle member (not shown) of the gas meter 10 into the through hole 33a, the gas meter 10 can be carried while supporting the handle member.

Second Embodiment
The second embodiment differs from the first embodiment mainly in the configuration of the plate-shaped member 50 serving as the co-rotation prevention mechanism 30. Therefore, in the following second embodiment, the configuration of the plate-shaped member 50 will be mainly described, and the same components as those in the first embodiment will be denoted by the same reference numerals and the description thereof may be omitted.

As shown in FIG. 4, in the co-rotation prevention state, the co-rotation prevention mechanism 30 of the meter joint structure 100 according to the second embodiment is a plate-shaped member 50 that is interposed between the first cylindrical body 12 as the cylindrical body 12, 22 between the gas pipe outlet 3a and the meter inlet 43 and the second cylindrical body 22 as the cylindrical body 12, 22 between the gas pipe inlet 4a and the meter outlet 44, and is arranged in the direction of the cylindrical axis of the first cylindrical body 12 (the direction of the arrow Z). It is made up of first chamfered portions 12a, 12b, 12c, 12d (corresponding to the first abutted surface of the first abutted portion) that are formed by chamfering the outer peripheral portion along the cylindrical axis direction (arrow Z direction) of the second cylindrical main body 22 and that can engage with one end of the plate-shaped member 50, and second chamfered portions 22a, 22b, 22c, 22d (corresponding to the second abutted surface of the second abutted portion) that are formed by chamfering the outer peripheral portion along the cylindrical axis direction (arrow Z direction) of the second cylindrical main body 22 and that can engage with the other end of the plate-shaped member 50.

Here, the first chamfered portions 12a, 12b, 12c, and 12d provided on the first cylindrical main body 12 are composed of an inner first chamfered portion 12a that is between the first cylindrical main body 12 and the second cylindrical main body 22 in the inter-body direction, an outer first chamfered portion 12c that is on the outside of the first cylindrical main body 12 and the second cylindrical main body 22 in the inter-body direction, a front side first chamfered portion 12d on the front side (arrow Y tip side) of the gas meter 10 in the front-to-back direction (arrow Y direction) perpendicular to the cylindrical axis P1 of the first cylindrical main body 12 and the inter-body direction, and a rear side first chamfered portion 12b on the rear side (arrow Y tip side) of the gas meter 10 in the front-to-back direction (arrow Y direction) perpendicular to the cylindrical axis P1 of the first cylindrical main body 12 and the inter-body direction. That is, the inner first chamfered portion 12a and the outer first chamfered portion 12c are provided in parallel, and the front side first chamfered portion 12d and the rear side first chamfered portion 12b are provided in parallel.
Furthermore, the second chamfered portions 22a, 22b, 22c, and 22d provided on the second cylindrical main body 22 are composed of an inner second chamfered portion 22a that is between the first cylindrical main body 12 and the second cylindrical main body 22 in the inter-body direction, an outer second chamfered portion 22c that is on the outside of the first cylindrical main body 12 and the second cylindrical main body 22 in the inter-body direction, a front side second chamfered portion 22d on the front side (arrow Y tip side) of the gas meter 10 in the front-to-back direction (arrow Y direction) perpendicular to the cylindrical axis P2 of the second cylindrical main body 22 and the inter-body direction, and a rear side second chamfered portion 22b on the rear side (arrow Y base side) of the gas meter 10 in the front-to-back direction (arrow Y direction) perpendicular to the cylindrical axis P2 of the second cylindrical main body 22 and the inter-body direction. That is, the inner second chamfered portion 22a and the outer second chamfered portion 22c are provided in parallel, and the front side second chamfered portion 22d and the rear side second chamfered portion 22b are provided in parallel.

The plate-like member 34 of the second embodiment is composed of a first plate-like member 50 extending in the inter-body direction (arrow X direction) connecting the first cylindrical body 12 and the second cylindrical body 22 in the anti-rotation state, and a second plate-like member 60, and the first plate-like member 50 and the second plate-like member 60 are arranged as a whole to have a plane that extends along both the first cylindrical axis P1 of the first cylindrical body 12 and the second cylindrical axis P2 of the second cylindrical body 22.
In the above-described co-rotation prevention state, the first plate-shaped member 50 has a first abutment surface that abuts against both a portion of the first chamfered portions 12a, 12b, 12c, and 12d and a portion of the second chamfered portions 22a, 22b, 22c, and 22d.
The first abutment surface consists of an inner first abutment surface 51a abutting against the inner first chamfered portion 12a, an outer first abutment surface 51c abutting against the outer first chamfered portion 12c, a rear first abutment surface 51b abutting against the rear first chamfered portion 12b (corresponding to the rear first abutted surface as the first abutted surface), an inner second abutment surface 55a abutting against the inner second chamfered portion 22a, an outer second abutment surface 55c abutting against the outer second chamfered portion 22c, and a rear second abutment surface 55b abutting against the rear second chamfered portion 22b (corresponding to the rear second abutted surface as the second abutted surface).
In addition, in the above-mentioned co-rotation prevention state, the second plate-shaped member 60 has a second abutment surface that abuts against both a portion of the first chamfered portions 12a, 12b, 12c, and 12d and a portion of the second chamfered portions 22a, 22b, 22c, and 22d.
The second abutment surface consists of an inner first abutment surface 61a abutting against the inner first chamfered portion 12a, an outer first abutment surface 61c abutting against the outer first chamfered portion 12c, a front side first abutment surface 61d abutting against the front side first chamfered portion 12d (corresponding to the front side first abutted surface as the first abutted surface), an inner second abutment surface 65a abutting against the inner second chamfered portion 22a, an outer second abutment surface 65c abutting against the outer second chamfered portion 22c, and a front side second abutment surface 65d abutting against the front side second chamfered portion 22d (corresponding to the front side second abutted surface as the second abutted surface).

The first plate-like member 50 and the second plate-like member 60 are configured to be longer in the inter-body direction connecting the first cylindrical main body 12 and the second cylindrical main body 22 than the inter-body distance between the first cylindrical main body 12 and the second cylindrical main body 22, and are configured to be engageable in a manner in which a first one-end engagement opening 52 as a first one-end engagement portion formed at one end of the first plate-like member 50 in the inter-body direction is inserted into a second one-end engagement claw 62 as a second one-end engagement portion formed at one end of the second plate-like member 60 in the inter-body direction, and the first other-end engagement opening 54 as a first other-end engagement portion formed at the other end of the first plate-like member 50 in the inter-body direction is inserted into a second other-end engagement claw 64 as a second other-end engagement portion formed at the other end of the second plate-like member 60 in the inter-body direction.
Furthermore, in the anti-rotation state, when the first one-end engagement opening 52 and the second one-end engagement claw 62 are engaged and the first other-end engagement opening 54 and the second other-end engagement claw 64 are engaged outside the area between the first cylindrical main body 12 and the second cylindrical main body 22, a bolt T1a is provided between the first cylindrical main body 12 and the second cylindrical main body 22 as a fastening portion for fastening the first plate-shaped member 50 and the second plate-shaped member 60, and a female screw portion T1b into which the bolt T1a screws is provided on the first plate-shaped member 50.

To add further explanation, in the second embodiment, the one-end side second plate-shaped member 60 is composed of a one-end side second plate-shaped member 61 that abuts against the first cylindrical main body 12, and an other-end side second plate-shaped member 65 that abuts against the second cylindrical main body 22, and the one-end side second plate-shaped member 61 is composed of a second one-end engaging claw 62, an inner first abutment surface 61a, an outer first abutment surface 61c, and a front side first abutment surface 61d, and the other-end side second plate-shaped member 65 is composed of a second other-end engaging claw 64, an inner second abutment surface 65a, an outer second abutment surface 65c, and a front side second abutment surface 65d.
In the anti-rotation state, the first plate-like member 50, the one-end second plate-like member 61, and the other-end second plate-like member 65 have overlapping portions where they overlap each other between the first cylindrical main body 12 and the second cylindrical main body 22. In the overlapping portions, the first plate-like member 50 has a first opening 53 with the above-mentioned female screw portion T1b screwed on its inner surface, the one-end second plate-like member 61 and the other-end second plate-like member 65 have second openings 63, and the bolt T1a is inserted through the first opening 53 and the second opening 63 and screwed into the female screw portion T1b.

Third Embodiment
The co-rotation prevention mechanism 30 can also be realized with a configuration that does not use the plate-like member 34 .
Hereinafter, a meter joint structure 100 according to a third embodiment will be described with reference to FIGS.
In the third embodiment, the meter joint structure 100 provided between the meter inlet 43 and the gas pipe outlet 3a, and the meter joint structure 100 provided between the meter outlet 44 and the gas pipe inlet 4a all have the same configuration, so the following will explain the meter joint structure 100 provided between the meter inlet 43 and the gas pipe outlet 3a as an example.

In the meter joint structure 100 according to the third embodiment, as shown in Figs. 5 to 7, the first cylindrical body 12 has a third chamfered portion 12g (in the third embodiment, the chamfered surface corresponds to the sides of the hexagon when viewed in the axial direction along the first cylindrical axis P1 in Fig. 6(b)) formed by chamfering the outer circumferential portion along the first cylindrical axis P1 of the first cylindrical body 12, and the joint nut 13 has a body side end surface 13b formed on the first cylindrical body 12 side and a fourth chamfered portion 13c (in the third embodiment, the chamfered surface corresponds to the sides of the hexagon when viewed in the axial direction along the first cylindrical axis P1 in Fig. 7(b)) formed by chamfering the outer circumferential portion along the first cylindrical axis P1 as shown in Figs. 6 and 7.

The anti-rotation mechanism 30 includes a cylindrical main body outer fitting member 70 that is fitted onto the outer periphery of the first cylindrical main body 12 to be slidable along the first cylindrical axis P1 and has first flat surfaces 72a, 72b that can abut against the third chamfered portion 12g, and that is in a first fitting position (shown in Figure 7) in which relative rotation with the first cylindrical main body 12 is prohibited when the first flat surfaces 72a, 72b abut against the third chamfered portion 12g, and a fastening portion that positions the cylindrical main body outer fitting member 70 relative to the first cylindrical main body 12 in the direction along the first cylindrical axis P1.
More specifically, as shown in Fig. 5, the cylindrical main body outer fitting member 70 is composed of a first half member 70a and a second half member 70b. The fastening portion is composed of a first bolt T1a and a first nut T1b which fasten a first end flange portion 74a provided at one end of the first half member 70a to a second end flange portion 74b provided at one end of the second half member 70b, and a second bolt T2a and a second nut T2b which fasten a first other end flange portion 73a provided at the other end of the first half member 70a to a second other end flange portion 73b provided at the other end of the second half member 70b.

Furthermore, as shown in FIG. 6, the coupling nut cover member 80 has a second flat surface portion 83 that can abut against the body side end face 13b of the coupling nut 13, and a third flat surface portion 82 that can abut against the fourth chamfered portion 13c of the coupling nut 13, and is fitted onto the coupling nut 13 in a second external fitting position (shown in FIG. 6) in which relative rotation with the coupling nut 13 about the first cylinder axis P1 is prohibited when the body side end face 13b abuts against the second flat surface portion 83 and the fourth chamfered portion 13c abuts against the third flat surface portion 82.

In the anti-rotation state, the cylindrical main body outer fitting member 70 is in a first outer fitting position and the joint nut cover member 80 is in a second outer fitting position, and the fastening portion positions the cylindrical main body outer fitting member 70 in a direction along the first cylindrical axis P1, and has a relative rotation prohibition portion that prohibits relative rotation between the cylindrical main body outer fitting member 70 and the joint nut cover member 80 in the screwing and tightening direction of the union nut 8a.
Specifically, as shown in Figures 5 to 7, when the cylindrical main body outer fitting member 70 is in the first outer fitting position and the joint nut cover member 80 is in the second outer fitting position, and the fastening portion positions the cylindrical main body outer fitting member 70 in the direction along the first cylindrical axis P1, the relative rotation prohibiting portion is composed of a first annular gear portion 71 formed in an annular shape on the cylindrical main body outer fitting member 70 and a second annular gear portion 72 formed in annular shape on the joint nut cover member 80 at the portion where the cylindrical main body outer fitting member 70 and the joint nut cover member 80 abut against each other in the direction along the first cylindrical axis P1.
In the relative rotation prohibited state, the first annular gear portion 71 and the second annular gear portion 72 are engaged with each other, and thus relative rotation between the cylindrical main body outer fitting member 70 and the coupling nut cover member 80 is prohibited, and thus relative rotation between the first cylindrical main body 12 and the coupling nut 13 is also prohibited. In the relative rotation prohibited state, if the coupling nut 13 is properly fastened to the first annular screw portion 43a, the relative rotation between the union nut 8a and the first cylindrical main body 12 can be prevented when the union nut 8a is screwed into the second annular screw portion 11 formed integrally with the first cylindrical main body 12.

[Another embodiment]
(1) In the above first embodiment, the planar portion of the plate-like member 34 is a plane that is perpendicular to both the first cylindrical body 12 and the second cylindrical body 22. However, the planar portion does not have to be perpendicular to both the first cylindrical body 12 and the second cylindrical body 22. As another example, the planar portion of the plate-like member 34 may be a plane that intersects with both the first cylindrical body 12 and the second cylindrical body 22 at a predetermined angle other than 90° (for example, 45°).

(2) In the above first embodiment, an example configuration is shown in which the first cylindrical main body 12 has a pair of first opposing surfaces as the first chamfered portion 12b that abut against each of the pair of first engaging claws 31 in the anti-rotation state, and the second cylindrical main body 22 has a pair of second opposing surfaces as the second chamfered portion 22b that abut against each of the pair of second engaging claws 32 in the anti-rotation state.
However, the first chamfered portion 12b may have not only a pair of opposing surfaces but also three or more surfaces, and the second chamfered portion 22b may have not only a pair of opposing surfaces but also three or more surfaces.
For example, the first chamfered portion 12b can have two pairs of opposing surfaces, and the second chamfered portion 22b can have two pairs of opposing surfaces, so that even if the first cylindrical main body 12 and the second cylindrical main body 22 rotate around the cylindrical axis P1, P2, the pair of locking claws 31, 32 provided on the plate-shaped member 34 can easily lock, improving ease of installation.

(3) As shown in FIG. 8 , the first plate member 50 of the meter joint structure 100 according to the second embodiment may be configured to be able to attach a handle member (not shown) of a gas meter, similar to the first embodiment.
That is, a one-side base 91 extending from the first plate-like member 50 to one side and a other-side base 92 extending to the other side are welded in a perpendicular direction perpendicular to the first cylindrical axis P1 and the second cylindrical axis P2 and the inter-body direction between the first cylindrical body 12 and the second cylindrical body 22.
Furthermore, each of the one side base portion 91 and the other side base portion 92 is provided with a pair of trapezoidal plate portions 33 extending in a direction along the first cylindrical axis P1 and the second cylindrical axis P2, and a through hole 33a is formed in each of the pair of trapezoidal plate portions 33.
By inserting an end of a handle member (not shown) of the gas meter 10 into the through hole 33a, the gas meter 10 can be carried while supporting the handle member.
In addition, in this other embodiment, the first bolt T1a is inserted through the first opening 53a formed in the first plate-shaped member 50 and the second opening 63a formed in the one-end side second plate-shaped member 61, and is screwed into the first female screw portion T1b screwed into the inner surface of the first opening 53a.
Furthermore, a second bolt T2a is inserted through a third opening 53b formed in the first plate-shaped member 50 and a fourth opening 63b formed in the other end side second plate-shaped member 65, and is screwed into a second female screw portion T2b threaded into the inner surface of the third opening 53b.
The fastening positions of the first bolt T1a and the second bolt T2a are located on either side of the through hole 33a in the inter-body direction.

(4) As an alternative embodiment of the meter joint structure 100 shown in the second embodiment, the configuration shown in FIG. 9 may be adopted.
For example, depending on the housing shape of the new gas meter 10, it is also envisaged that the shape will have a part of the gas meter housing protruding between the first cylindrical body 12 and the second cylindrical body 22, toward the gas pipe end side beyond the coupling nuts 13, 23, in the direction along the first cylindrical axis P1 and the second cylindrical axis P2.
In order to deal with such a case, as shown in Figure 9, both the first plate-shaped member 50 and the second plate-shaped member 60 may form an insertion opening K between the first cylindrical main body 12 and the second cylindrical main body 22, when viewed in the cylindrical axis direction along the first cylindrical axis P1 and the second cylindrical axis P2, in a state in which co-rotation is prevented, through which the housing protruding portion 10b, which is part of the housing 10a of the gas meter 10, can be inserted.
That is, the first plate-like member 50 has a rear side bent portion 57 that bends toward the rear side of the gas meter 10 in an orthogonal direction perpendicular to the first cylindrical axis P1 and the second cylindrical axis P2 and the inter-body direction between the first cylindrical main body 12 and the second cylindrical main body 22, and the second plate-like member 60 has a front side bent portion 67 that bends toward the front side of the gas meter 10 in an orthogonal direction perpendicular to the first cylindrical axis P1 and the second cylindrical axis P2 and the inter-body direction between the first cylindrical main body 12 and the second cylindrical main body 22, and an insertion opening K is formed between the rear side bent portion 57 and the front side bent portion 67.
Here, for the fastening portion that fastens the first plate-shaped member 50 and the second plate-shaped member 60, a configuration equivalent to that of the above-mentioned alternative embodiment (3) is adopted, and the fastening positions of the first bolt T1a and the second bolt T2a are located on both sides of the insertion opening K in the direction between the main bodies.

(5) In the first embodiment described above, the plate-like member 34 is shaped to extend from the first cylindrical body 12 to the second cylindrical body 22. However, for example, as shown in FIG. 10 , it is also acceptable to provide a separate end side plate-like member 50a on the first cylindrical body 12 side and a separate end side plate-like member 50b on the second cylindrical body 22 side, and configure each to be fixed around the cylindrical axis P1 or P2.
For example, as shown in FIG. 10 , the one-end side plate member 50a is configured so that a first bolt T1a is inserted therethrough and is clamped between the bolt head of the first bolt T1a and a first nut T1b, and the tip of the first bolt T1a is fastened to a female screw portion T1c formed in the housing 10a of the gas meter 10.
In addition, the other end side plate member 50b is configured so that the second bolt T2a is inserted therethrough and clamped between the bolt head of the second bolt T2a and the second nut T2b, and the tip of the second bolt T2a is fastened to a female screw portion T2c formed in the housing 10a of the gas meter 10.

(6) The insertion opening K described in the third embodiment above can also be provided in the rotation prevention mechanism 30 of other embodiments. For example, a configuration in which an insertion opening K is provided in one of the plate-like members 34 of the first embodiment can also be adopted.

The configurations disclosed in the above embodiment (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, provided no contradictions arise. Furthermore, the embodiments disclosed in this specification are merely examples, and the present invention is not limited to these embodiments. Appropriate modifications can be made without departing from the scope of the present invention.

The meter joint structure of the present invention can be effectively used as a meter joint structure that can set the up and down positions of the meter display unit on the gas meter to be approximately the same before and after replacement, even if a gas meter with a different housing shape is connected before and after the replacement, and can also prevent co-rotation during installation, improving workability.

3a : Gas pipe outlet 4a : Gas pipe inlet 8a : Union nut 9a : Union nut 10 : Gas meter 11 : Second annular screw portion 12 : First cylindrical main body 12a : First inner chamfered portion 12a : First chamfered portion 12b : First chamfered portion 12c : First chamfered portion 12d : First chamfered portion 12g : Third chamfered portion 13 : Coupling nut 13b : Main body side end face 13c : Fourth chamfered portion 21 : Second annular screw portion 22 : Second cylindrical main body 22a : Second chamfered portion 22b : Second chamfered portion 22c : Second chamfered portion 22d : Second chamfered portion 23 : Coupling nut 30 : Co-rotation prevention mechanism 31 : First locking claw 32 : Second locking claw 33a : Through hole 34 : Plate-shaped member 34a : Planar part 43 : Meter inflow part 43a : First annular screw part 44 : Meter outflow part 44a : First annular screw part 50 : First plate-shaped member 51a : Inner first contact surface 51b : Rear side first contact surface 51c : Outer first contact surface 55a : Inner second contact surface 55b : Rear side second contact Surface 55c: Second outer contact surface 60: Second plate member 61a: First inner contact surface 61c: First outer contact surface 61d: First front contact surface 64: Second other end engaging claw 65a: Second inner contact surface 65c: Second outer contact surface 65d: Second front contact surface 70: Cylindrical body external fitting member 72a: First flat part 72b :First plane part 80 : Joint nut cover member 82 : Third flat portion 83 : Second flat portion 100 : Meter joint structure K : Insertion opening P1 : First cylinder axis P2 : Second cylinder axis

Claims (7)

A meter joint structure that connects between a meter inlet portion, into which gas flows, of a meter flow end portion through which gas flows into and out of a gas meter that measures the flow rate of gas flowing through a gas pipe, and a gas pipe outlet portion, which is a gas pipe end portion of a primary gas pipe, and between a meter outlet portion, from which gas flows out, of the meter flow end portion, and a gas pipe inlet portion, which is a gas pipe end portion of a secondary gas pipe,
The gas pipe outlet portion and the gas pipe inlet portion are each provided with a union nut that is rotatable relative to an end portion of the gas pipe,
Each of the meter inlet portion and the meter outlet portion has a first annular screw portion formed along an outer periphery thereof into which the union nut can be screwed,
a cylindrical body having a second annular screw portion at one end into which the union nut can be screwed, and a coupling nut that can be screwed into the first annular screw portion at the other end, which is inserted so as to be relatively rotatable;
a co-rotation prevention mechanism capable of maintaining a co-rotation prevention state in which the cylindrical main body is prevented from co-rotating with the union nut at least when the union nut is screwed into the second annular screw portion ,
In the co-rotation prevention state, the co-rotation prevention mechanism
a plate-like member interposed between a first cylindrical body as the cylindrical body between the gas pipe outlet portion and the meter inlet portion and a second cylindrical body as the cylindrical body between the gas pipe inlet portion and the meter outlet portion;
a first contact portion formed on an outer circumferential portion of the first cylindrical body and capable of engaging one end of the plate-like member; and a second contact portion formed on an outer circumferential portion of the second cylindrical body and capable of engaging the other end of the plate-like member.
the plate-like member has a flat portion along a transverse direction intersecting a cylindrical axis of the first cylindrical body and a cylindrical axis of the second cylindrical body, and in a body-to-body direction connecting the first cylindrical body and the second cylindrical body, has a pair of first locking claws at one end of the plate-like member which are flat portions and extend in the body-to-body direction, and has a pair of second locking claws at the other end of the plate-like member which are flat portions and extend in the body-to-body direction,
a pair of first notches as the first abutted portions which abut against each of the pair of first engaging claws in the anti-rotation state, and a pair of second notches as the second abutted portions which abut against each of the pair of second engaging claws in the anti-rotation state. A meter joint structure that connects between a meter inlet portion, into which gas flows, of a meter flow end portion through which gas flows into and out of a gas meter that measures the flow rate of gas flowing through a gas pipe, and a gas pipe outlet portion, which is a gas pipe end portion of a primary gas pipe, and between a meter outlet portion, from which gas flows out, of the meter flow end portion, and a gas pipe inlet portion, which is a gas pipe end portion of a secondary gas pipe,
The gas pipe outlet portion and the gas pipe inlet portion are each provided with a union nut that is rotatable relative to an end portion of the gas pipe,
Each of the meter inlet portion and the meter outlet portion has a first annular screw portion formed along an outer periphery thereof into which the union nut can be screwed,
a cylindrical body having a second annular screw portion at one end into which the union nut can be screwed, and a coupling nut that can be screwed into the first annular screw portion at the other end, which is inserted so as to be relatively rotatable;
a co-rotation prevention mechanism capable of maintaining a co-rotation prevention state in which the cylindrical main body is prevented from co-rotating with the union nut at least when the union nut is screwed into the second annular screw portion,
In the co-rotation prevention state, the co-rotation prevention mechanism
a plate-like member interposed between a first cylindrical body as the cylindrical body between the gas pipe outlet portion and the meter inlet portion and a second cylindrical body as the cylindrical body between the gas pipe inlet portion and the meter outlet portion;
a first contact portion formed on an outer circumferential portion of the first cylindrical body and capable of engaging one end of the plate-like member; and a second contact portion formed on an outer circumferential portion of the second cylindrical body and capable of engaging the other end of the plate-like member .
the plate-like member includes a first plate-like member having a first abutment surface that abuts against both a first abutment surface of the first abutment portion and a second abutment surface of the second abutment portion in the co-rotation prevention state, and a second plate-like member having a second abutment surface that abuts against both the first abutment surface and the second abutment surface,
A meter joint structure including a fastening portion that clamps and fastens the first plate-shaped member and the second plate-shaped member when, in the anti-rotation state, the first abutment surface abuts against the first abutted portion and the second abutted portion and the second abutment surface abuts against the first abutted portion and the second abutted portion. The first abutment surface has a rear side first abutment surface against which the first abutment surface of the first plate-like member abuts, and a front side first abutment surface against which the second abutment surface of the second plate-like member abuts,
3. The meter joint structure according to claim 2, wherein the second abutment surface has a rear side second abutment surface against which the first abutment surface of the first plate-shaped member abuts, and a front side second abutment surface against which the second abutment surface of the second plate-shaped member abuts. the first plate-like member and the second plate-like member are configured to be longer than a distance between the first cylindrical body and the second cylindrical body in a body-to-body direction connecting the first cylindrical body and the second cylindrical body,
a first one-end engaging portion formed at one end of the first plate-like member in the inter-body direction and a second one-end engaging portion formed at one end of the second plate-like member in the inter-body direction are configured to be engageable with each other, and a first other-end engaging portion formed at the other end of the first plate-like member in the inter-body direction and a second other-end engaging portion formed at the other end of the second plate-like member in the inter-body direction are configured to be engageable with each other,
4. The meter fitting structure of claim 2 or 3, wherein in the anti-rotation state, the first one-end engaging portion and the second one-end engaging portion engage and the first other-end engaging portion engage with the second other-end engaging portion on the outside between the first cylindrical body and the second cylindrical body, and the fastening portion fastens the first plate-like member and the second plate-like member in the region between the first cylindrical body and the second cylindrical body. The meter fitting structure according to any one of claims 1 to 4, wherein in the anti-rotation state, the plate-shaped member forms an insertion opening between the first cylindrical body and the second cylindrical body, through which a part of the housing of the gas meter can be inserted, when viewed in a cylindrical axis direction along the cylindrical axis of the first cylindrical body and the second cylindrical body. The meter fitting structure according to any one of claims 1 to 5, wherein the plate-like member, in the anti-rotation state, is provided with a through hole at a central portion of the first cylindrical body and the second cylindrical body in a direction intersecting both the cylindrical axis centers of the first cylindrical body and the second cylindrical body and the direction between the bodies. A meter joint structure that connects between a meter inlet portion, into which gas flows, of a meter flow end portion through which gas flows into and out of a gas meter that measures the flow rate of gas flowing through a gas pipe, and a gas pipe outlet portion, which is a gas pipe end portion of a primary gas pipe, and between a meter outlet portion, from which gas flows out, of the meter flow end portion, and a gas pipe inlet portion, which is a gas pipe end portion of a secondary gas pipe,
The gas pipe outlet portion and the gas pipe inlet portion are each provided with a union nut that is rotatable relative to an end portion of the gas pipe,
Each of the meter inlet portion and the meter outlet portion has a first annular screw portion formed along an outer periphery thereof into which the union nut can be screwed,
a cylindrical body having a second annular screw portion at one end into which the union nut can be screwed, and a coupling nut that can be screwed into the first annular screw portion at the other end, which is inserted so as to be relatively rotatable;
a co-rotation prevention mechanism capable of maintaining a co-rotation prevention state in which the cylindrical main body is prevented from co-rotating with the union nut at least when the union nut is screwed into the second annular screw portion,
The cylindrical main body includes a third chamfered portion formed by chamfering an outer circumferential portion of the cylindrical main body along a cylindrical axis direction,
The joint nut includes a body side end surface formed on the body side of the cylindrical body, and a fourth chamfered portion formed by chamfering an outer circumferential portion along the cylindrical axis direction,
The co-rotation prevention mechanism is
a cylindrical body outer fitting member that is fitted onto an outer circumferential portion of the cylindrical body, is slidable along the cylindrical axial direction, and has a first flat portion that can abut against the third chamfered portion, and is in a first fitting position in which relative rotation with respect to the cylindrical body is prohibited when the first flat portion abuts against the third chamfered portion;
a fastening portion for positioning the cylindrical main body outer fitting member relative to the cylindrical main body in the cylindrical axial direction;
a coupling nut cover member having a second flat portion capable of contacting the body side end face of the coupling nut and a third flat portion capable of contacting the fourth chamfered portion of the coupling nut, the body side end face and the second flat portion being in contact with each other and the fourth chamfered portion and the third flat portion being in contact with each other, and the coupling nut cover member is fitted onto the coupling nut in a second externally fitted position in which relative rotation with respect to the coupling nut about the cylindrical axis is prohibited;
In the anti-rotation state, when the cylindrical main body outer fitting member is in the first outer fitting position and the joint nut cover member is in the second outer fitting position, and the fastening portion positions the cylindrical main body outer fitting member in the cylindrical axial direction, the meter fitting structure has a relative rotation prohibition portion that prohibits relative rotation between the cylindrical main body outer fitting member and the joint nut cover member in the screwing and tightening direction of the union nut .

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