Joint Structure

Abstract

To provide an insertion type joint structure which uses a C-type elastic ring for connecting an outside pipe body and an inside pipe body in a locked state, normally has a reliable locking function, and enables easy removal of the C-type elastic ring with special operation when the removal is required.SOLUTION: A C-type elastic ring 3 is engaged with both an inward annular recessed groove 11 of an outside pipe body 1 and an outward annular recessed groove 21 of an inside pipe body 2. In the outside pipe body 1, a cutout part 10 is formed which is communicated through the outer peripheral face with the inward annular recessed groove 11. At least one opening end 31 of the C-type elastic ring 3 is exposed into the cutout part 10 so as to be pulled out as it is.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a joint structure, and more particularly to a plug-in type joint structure equipped with a retaining ring. [Background technology]

[0002] For example, as a joint structure for connecting two pipes through which a fluid flows, such as when connecting a piping joint member to the connecting tube of a gas valve, there is a plug-in type in which one pipe is inserted into the other pipe in a locked state.

[0003] In the plug-in type described above, annular grooves that open toward the opposing surfaces are formed circumferentially on the inner surface of the outer tube located on the outside and the outer surface of the inner tube located on the inside, and when the open ends of each annular groove are aligned with each other, a C-shaped elastic ring is inserted as an anti-slip ring so as to straddle both annular grooves, thereby connecting the outer tube and inner tube in a non-slip state. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-124222 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above-described joint structure, it is difficult to remove the C-shaped elastic ring, which is fitted in a resilient state so as to engage with both the inward-facing annular groove formed on the inner peripheral surface of the outer pipe and the outward-facing annular groove formed on the outer peripheral surface of the inner pipe. Therefore, once the outer pipe and inner pipe are connected in a locked state via the C-shaped elastic ring, they cannot be disassembled. Therefore, if there is a problem with either the connecting tube of the gas valve or the joint member of the piping, it is not possible to separate them and replace or repair one, and the entire gas valve must be replaced.

[0006] The present invention was made in consideration of the above problems, and aims to provide a joint structure in which an inner tube is inserted into an outer tube and a C-shaped elastic ring is placed between the two to connect them in a non-disconnecting state, which has a reliable non-disconnecting function under normal conditions, and which allows the C-shaped elastic ring to be easily removed by a special operation when removal is necessary. [Means for solving the problem]

[0007] The technical means for solving the above problem is as follows: In a plug-in type joint structure in which an inner pipe is inserted into an outer pipe and held in a non-detachable state, An inward-facing annular groove that opens inward is formed on the inner peripheral surface of the outer pipe body over the entire circumferential direction, An outwardly facing annular groove that opens outward is formed on the outer peripheral surface of the inner pipe body over the entire circumferential direction, A C-shaped elastic ring is provided which elastically returns to its original position when the inward annular groove and the outward annular groove are aligned, and simultaneously engages with both of them. The outer tubular body has a notch formed in its outer peripheral surface, which is connected to the inward annular groove and has an axial width greater than the wire diameter of the C-shaped elastic ring, the cutout portion is formed by cutting out the outer pipe body parallel to a tangent to an outer circumferential circle, and is composed of a cutout hole portion communicating with the inward annular groove and cutout surfaces of the outer pipe body positioned on the same plane on both circumferential sides of the cutout hole portion, The notch hole through the C-shaped elastic ring Opening The free end portion can be exposed so as to be drawable.

[0008] The above technical means operates as follows. The C-shaped elastic ring is fitted onto the outward-facing annular groove of the inner pipe, and the inner pipe is inserted into one open end of the outer pipe while reducing its diameter so that it does not protrude outward from the outward-facing annular groove. When the outward-facing annular groove of the inner pipe faces the inward-facing annular groove of the outer pipe, the C-shaped elastic ring elastically returns to its original position and expands in diameter to straddle both the inward-facing annular groove and the outward-facing annular groove. This causes the constituent walls of the outward-facing annular groove and the inward-facing annular groove to engage with the C-shaped elastic ring, connecting the outer pipe and the inner pipe in a non-disconnected state. The C-shaped elastic ring, in its resiliently restored state, prevents the outer pipe and the inner pipe, which are connected in a non-disconnected state, from accidentally separating, maintaining the connection. In the connected state, a portion of the C-shaped elastic ring is exposed and visible through a cutout formed on the outer circumferential surface of the outer pipe, allowing for easy viewing.

[0009] To disassemble the outer and inner tubes connected as described above, the C-shaped elastic ring is rotated circumferentially while supporting the portion exposed in the notch with a tool. Because the width of the notch is set larger than the wire diameter of the C-shaped elastic ring, a tool can be inserted into the notch to rotate the C-shaped elastic ring circumferentially. Then, once at least one open end of the C-shaped elastic ring is exposed in the notch, the open end can be pulled outward from the notch to remove the C-shaped elastic ring. This allows the inner tube to be pulled out of the outer tube, making them separable.

[0010] Also, The cutout can be formed simply by cutting parallel to a tangent to the outer circumferential circle of the outer tubular body, making it easy to process the outer tubular body. Furthermore, after exposing the open end of the C-shaped elastic ring in the cutout hole, the C-shaped elastic ring can be pulled out to the side of the cutout along the cutout surface, which is positioned at the same height as the open end of the cutout hole. This makes it even easier to disassemble the outer and inner tubular bodies.

[0011] Another technical means for solving the above problem is: In a plug-in type joint structure in which an inner pipe is inserted into an outer pipe and held in a non-detachable state, An inward-facing annular groove that opens inward is formed on the inner peripheral surface of the outer pipe body over the entire circumferential direction, An outwardly facing annular groove that opens outward is formed on the outer peripheral surface of the inner pipe body over the entire circumferential direction, A C-shaped elastic ring is provided which elastically returns to its original position when the inward annular groove and the outward annular groove are aligned, and simultaneously engages with both of them. The outer tubular body has a notch formed in its outer peripheral surface, which is connected to the inward annular groove and has an axial width greater than the wire diameter of the C-shaped elastic ring, the cutout portion is composed of a cutout hole portion communicating with the inward annular groove and cutout surfaces of the outer pipe body located on both sides of the cutout hole portion in the circumferential direction, The cutout surface is an inclined surface cut out obliquely so as to form an acute angle with the annular bottom of the inward annular groove. year, The open end of the C-shaped elastic ring can be exposed and pulled out through the cutout hole. is. In this device, the cutout surfaces located on both circumferential sides of the cutout hole consist of inclined surfaces that slope away from each other toward the outer peripheral surface of the outer tube body, and the C-shaped elastic ring can be easily removed by pulling up the open end of the C-shaped elastic ring exposed in the cutout hole along these inclined surfaces.

[0012] In the above joint structure, the notches are preferably provided at a plurality of locations on the outer peripheral surface of the outer pipe body. The open end of the C-shaped elastic ring only needs to be exposed in one of the multiple cutouts, so the rotation angle of the C-shaped elastic ring can be small. This makes it easier to expose the open end of the C-shaped elastic ring from the cutout, and provides a joint structure that makes it easier to remove the C-shaped elastic ring.

[0013] In the above joint structure, the notch is preferably shaped to be open toward one end side in the axial direction of the outer pipe body. Since the width of the notch in the axial direction is increased, it becomes easier to turn the C-shaped elastic ring with a tool or pull out the open end portion through the notch.

[0014] In the above joint structure, preferably, the axial width of the inward annular groove of the outer pipe body or the outward annular groove of the inner pipe body is set to be larger than the wire diameter of the C-shaped elastic ring. In this case, when the inner tube is inserted into the outer tube, the inward annular groove and the outward annular groove easily align, making it easy to elastically return the C-shaped elastic ring and connect the two in a locked state. Furthermore, after connection, the outer tube and inner tube are movable in the axial direction, allowing for fine adjustment in the length direction.

[0015] In the above joint structure, it is preferable that an airtight seal member is interposed between the two opposing surfaces located further back in the outer pipe body than the inward annular groove and closer to the open end than the outward annular groove of the inner pipe body. When the inner pipe is inserted into the outer pipe and the inward-facing annular groove is aligned with the outward-facing annular groove, the outer peripheral surface of the open end of the inner pipe corresponds to the inner peripheral surface of the outer pipe at the back of the outer pipe. By interposing an airtight seal member between the two, the outer and inner pipes can be connected in an airtight and non-disconnected state. [Effects of the Invention]

[0016] The present invention has the following unique effects due to the above-described configuration. When the inner tube is inserted into the outer tube, the C-shaped elastic ring secures the two together. Once connected by the C-shaped elastic ring, the outer and inner tubes cannot be accidentally separated, so the connection can be maintained for a long period of time. When connected, part of the C-shaped elastic ring is exposed through a notch formed in the outer tube. To separate the outer and inner tubes, insert a tool into the notch and rotate the C-shaped elastic ring along the annular groove until at least one open end of the C-shaped elastic ring appears in the notch. The C-shaped elastic ring can then be removed by pulling out the open end that appears in the notch with the tool. In this way, the C-shaped elastic ring can be removed by a special operation, and the outer and inner tubes can be separated. For example, if a defect or malfunction occurs in either the piping joint member serving as the outer pipe or the connecting tubular portion of the gas valve serving as the inner pipe, the C-shaped elastic ring can be removed using the above-described procedure to separate the two, allowing replacement or repair of either the gas valve or the joint member alone, eliminating the inconvenience of having to discard the entire gas valve with the joint member connected. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a cross-sectional view showing a connection state between a gas valve and a joint member employed in a joint structure according to a first embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged cross-sectional view of a main part of FIG. [Figure 3] 2 is a cross-sectional view taken along the line XX in FIG. 1. [Figure 4] 4 is a cross-sectional view showing a state in which the C-shaped elastic ring is rotated from the state shown in FIG. 3. FIG. [Figure 5] 1 is a perspective view showing a connection state between a gas cock and a joint member employed in a joint structure according to a first embodiment of the present invention. FIG. [Figure 6] 10 is an enlarged cross-sectional view of a main portion showing the connection state between a gas cock and a joint member employed in a joint structure according to a second embodiment of the present invention. FIG. [Figure 7] 10 is an enlarged side view of a main portion showing the connection state between a gas cock and a joint member employed in a joint structure of a third embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, the best mode for carrying out the present invention will be described with reference to the accompanying drawings. FIG. 1 shows the joint structure of the first embodiment implemented at the connection between the connecting tube portion (2), which is the open end of the gas passage (20) of the gas valve (G), and the joint member (1) that can be connected to the gas intake tube portion of a gas appliance or a gas pipe.

[0019] The coupling member (1) is a pipe that is fitted onto the connecting tubular portion (2) of the gas valve (G) in an airtight and non-detachable state, and in this embodiment, the coupling member (1) functions as the outer pipe of the invention, while the connecting tubular portion (2) of the gas valve (G) functions as the inner pipe of the invention.

[0020] As shown in Figures 1 and 2, three first to third outward-facing annular grooves (21), (22), and (23) that open outward are formed on the outer peripheral surface of the connecting tubular portion (2) along the entire circumferential direction, and rubber airtight O-rings (30) are housed in the two second and third outward-facing annular grooves (22) and (23) located near the open end of the connecting tubular portion (2) as airtight sealing members.

[0021] The airtight O-ring 30 is an annular body having an inner diameter that fits tightly against the small-diameter portions formed by the annular bottom surfaces 220, 230 of the second and third outward annular grooves 22, 23, and the wire diameter of the airtight O-ring 30 is set to be equal to or greater than the depth of the second and third outward annular grooves 22, 23. As a result, when the airtight O-ring 30 is fitted into the second and third outward annular grooves 22, 23, the outer peripheral surface of the airtight O-ring 30 slightly protrudes from the open ends of the second and third outward annular grooves 22, 23.

[0022] A C-shaped elastic ring (hereinafter referred to as the C-ring 3) is fitted into the first outward annular groove 21 located at the innermost part of the connecting tubular part 2. The axial width of the annular bottom surface 210 of the first outward annular groove 21 is set larger than the wire diameter of the C-ring 3, and the inner diameter of the C-ring 3 in a free state is set larger than the tubular diameter defined by the annular bottom surface 210. As a result, the outer peripheral surface of the C-ring 3 is accommodated in the first outward annular groove 21 in a manner that protrudes from the open end.

[0023] Furthermore, an inwardly directed annular groove (11) that opens inward of the coupling member (1) is formed over the entire circumferential direction on the inner peripheral surface (12) of the coupling member (1) serving as the outer tubular body at a predetermined position that corresponds to the first outwardly directed annular groove (21) when the connecting tubular portion (2) is completely inserted into the coupling member (1). The axial width of the annular groove (11) is set to be larger than the wire diameter of the C-ring (3), and the depth of the inwardly directed annular groove (11) to the annular bottom surface (110) is set to be shallower than the wire diameter of the C-ring (3). In this first embodiment, the annular bottom surface (210) of the first outward annular groove (21) is set to be wider in the axial direction than the annular bottom surface (110) of the inward annular groove (11).

[0024] To connect the coupling member (1) to the connecting tubular portion (2) in an externally fitted state, the C-ring (3) fitted into the first outward annular groove (21) of the connecting tubular portion (2) is reduced in diameter so as to be accommodated within the first outward annular groove (21), and the airtight O-rings (30) fitted into the second and third outward annular grooves (22) and (23) are compressed while the connecting tubular portion (2) is inserted from one end (13) of the coupling member (1).

[0025] With the connecting tubular portion 2 inserted into the coupling member 1, the airtight O-ring 30 is pressed and deformed by the inner peripheral surface 12 of the coupling member 1 and comes into close contact with the inner peripheral surface 12 of the coupling member 1, thereby ensuring airtightness between the coupling member 1 and the connecting tubular portion 2. When the inward annular groove 11 of the coupling member 1 is aligned with the first outward annular groove 21 of the connecting tubular portion 2, the C-ring 3, which has been accommodated in the first outward annular groove 21 in a reduced diameter state, elastically returns to its original position, thereby expanding its diameter toward the inward annular groove 11 of the coupling member 1 and pressing against the annular bottom surface 110 of the inward annular groove 11. In this embodiment, the axial width of the annular bottom surface (210) of the first outward annular groove (21) is set wider than that of the annular bottom surface (110) of the inward annular groove (11), making it easier to align the inward annular groove (11) with the first outward annular groove (21) and to elastically return the C-ring (3).

[0026] Furthermore, because the depth of the inward annular groove 11 is set shallower than the wire diameter of the C-ring 3, the elastically restored C-ring 3 protrudes inward from the open end of the inward annular groove 11 and enters the first outward annular groove 21 of the connecting tubular part 2. As a result, the C-ring 3 is engaged with both the inward annular groove 11 and the first outward annular groove 21, and the coupling part 1 is connected to the connecting tubular part 2 in a non-disconnected state by the C-ring 3 in its elastically restored state. In this connected state, the wire diameter of the C-ring (3), the axial width of the annular bottom surface (110) of the inward annular groove (11), and the axial width of the annular bottom surface (210) of the first outward annular groove (21) are set to different sizes, so that the protruding length of the coupling member (1) connected to the connecting tube portion (2) of the gas valve (G) can be finely adjusted.

[0027] 3, the coupling member 1 is cut out parallel to a tangent line L to the outer circumferential circle of the coupling member 1, from its outer circumferential surface to the annular bottom surface 110 of the inward annular groove 11, to a predetermined depth. This cutout 10 is formed by a cutout hole 10a that communicates with the inward annular groove 11 and cutout surfaces 10b of the coupling member 1 located on both sides of the cutout hole 10a in the circumferential direction. When the coupling member 1 is connected to the connecting cylindrical portion 2 via the C-ring 3, a portion of the C-ring 3 is exposed and visible through the cutout hole 10a of the cutout 10, as shown in FIG. 3 and FIG. 1. The width of the notch (10) in the axial direction is set to be larger than the wire diameter of the C-ring (3).

[0028] The C-ring (3), which has elastically returned to its original position in the direction of diameter expansion so as to press against the annular bottom surface (110) of the inward annular groove (11) of the coupling member (1), cannot be reduced in diameter. Therefore, once the coupling member (1) and the connecting tubular portion (2) are connected by the C-ring (3), they cannot normally be separated. Below, we will explain what happens when it becomes necessary to separate the coupling member (1) and the connecting tubular portion (2), such as when a malfunction occurs at the connection point between the coupling member (1) and the connecting tubular portion (2) or when there is a defect in one of them.

[0029] First, a dedicated tool (not shown) is used to rotate the C-ring 3 exposed in the notched hole 10a of the cutout 10. The axial widths of the cutout 10, the annular bottom surface 110 of the inward annular groove 11, and the annular bottom surface 210 of the first outward annular groove 21 are set larger than the wire diameter of the C-ring 3, so that the tool can be easily inserted into the cutout 10 to rotate the part of the C-ring 3 exposed in the cutout hole 10a along the inward annular groove 11.

[0030] Then, as shown in Fig. 4, when one open end 31 of the C-ring 3 appears inside the cutout hole 10a, the open end 31 is pulled outward from the cutout 10. In this embodiment, by cutting the coupling member 1 parallel to the tangent L to the outer circumferential circle, when the cutout 10 is in an upward position as shown in Figs. 3 and 4, cutout surfaces 10b are positioned horizontally on both sides of the cutout hole 10a at the same height as the open end of the cutout hole 10a. Therefore, when the open end 31 of the C-ring 3 is pulled out with a tool, it can be pulled to the side of the coupling member 1 along the horizontal cutout surfaces 10b, as shown by the two-dot chain line in Fig. 5, and the C-ring 3 can be smoothly removed.

[0031] After removing the C-ring 3, the coupling member 1 can be separated from the gas valve G by pulling it out of the connecting tubular portion 2. Therefore, if a malfunction or defect occurs in the coupling member 1 or the connecting tubular portion 2, either one can be repaired or replaced, and there is no need to discard the gas valve G itself.

[0032] Furthermore, since the cutouts 10 as described above can be formed simply by cutting the joint member 1 in parallel, the joint member 1 can be easily processed. The cutout surface (10b) of the cutout portion (10) does not necessarily have to be a horizontal surface located on the same plane, but may be an inclined surface cut out at an angle so that the angle with the annular bottom portion (110) of the inward annular groove (11) is an acute angle, as shown by the dotted line in Figure 4. By making the cutout surface (10b) an inclined surface that inclines in directions away from each other toward the outer peripheral surface of the outer pipe body, the open end (31) of the C-ring (3) exposed in the cutout hole portion (10a) can be easily pulled up along the inclined surface, making it easy to remove the C-ring (3).

[0033] Figure 6 shows an enlarged cross-sectional view of a main part illustrating the connection state between the connecting tube portion (2) and the coupling member (1) of a gas valve (G) employing the coupling structure of the second embodiment, in which the axial width of the annular bottom surface (110) of the inward annular groove (11) is set wider than that of the annular bottom surface (210) of the first outward annular groove (21). In this case, similarly to the joint structure of the first embodiment described above, when fitting the joint member 1 onto the connecting tubular portion 2, it is easy to align the inward annular groove 11 with the first outward annular groove 21, which makes it easy to elastically return the C-ring 3 and connect the two in a non-detachable state. Furthermore, since the outer and inner tubular bodies are movable in the axial direction after connection, fine adjustment in the length direction is possible.

[0034] FIG. 7 is an enlarged side view of a main part showing the connection state between the connecting tubular portion 2 and the joint member 1 of a gas cock G employing the joint structure of the third embodiment. In this embodiment, the notch (10) employed in the first embodiment is cut out so as to open to one end (13) of the coupling member (1), which is the side into which the connecting tube portion (2) is inserted. This makes it easier to machine the coupling member (1), and also makes it easier to insert a special tool into the notch (10) to turn or pull out the C-ring (3) because the axial width of the notch (10) is greater.

[0035] 7, one notch 10 is formed on each end of the diameter of the coupling member 1. In this case, the open end 31 of the C-ring 3 only needs to be exposed to one of the two notches 10, so the rotation angle of the C-ring 3 can be small. By forming the notches 10 in multiple locations on the outer circumferential surface of the coupling member 1 in this way, the rotation angle of the C-ring 3 can be small, making it even easier to remove the C-ring 3.

[0036] In the above-described coupling structure, the coupling member 1 is connected to the connecting tubular portion 2 of the gas valve G via a C-ring 3 and an O-ring 30. This allows the coupling member 1 to be maintained in an airtight and non-detachable state with respect to the connecting tubular portion 2 for a long period of time. Furthermore, if it becomes necessary to separate the coupling member 1 or the connecting tubular portion 2, the C-ring 3 can be removed by a special operation using the notch 10 formed in the coupling member 1. In this way, the coupling member 1 can be separated from the connecting tubular portion 2 as needed, allowing either the gas valve or the coupling member to be replaced or repaired, eliminating the inconvenience of discarding the entire gas valve. [Explanation of symbols]

[0037] (1) Joint member (outer tube) (2) Connecting tube (inner tube) (3) C-ring (C-type elastic ring) (10) Notch (11) Inward circular groove (12) Inner surface (21) First outward annular groove (outward annular groove)

Claims

1. In a plug-in type joint structure in which an inner pipe is inserted into an outer pipe and held in a non-detachable state, An inward-facing annular groove that opens inward is formed on the inner peripheral surface of the outer pipe body over the entire circumferential direction, An outwardly facing annular groove that opens outward is formed on the outer peripheral surface of the inner pipe body over the entire circumferential direction, A C-shaped elastic ring is provided which elastically returns to its original position when the inward annular groove and the outward annular groove are aligned, and simultaneously engages with both of them; The outer tubular body has a notch formed in its outer peripheral surface, the notch communicating with the inward annular groove and having an axial width greater than the wire diameter of the C-shaped elastic ring, the cutout portion is formed by cutting out the outer pipe body parallel to a tangent to an outer circumferential circle, and is composed of a cutout hole portion communicating with the inward annular groove and cutout surfaces of the outer pipe body located on the same plane on both circumferential sides of the cutout hole portion, A joint structure in which the open end of the C-shaped elastic ring can be exposed and pulled out through the cutout hole.

2. A plug-in type joint structure in which an inner pipe is inserted into an outer pipe and held in a non-detachable state, An inward-facing annular groove that opens inward is formed on the inner peripheral surface of the outer pipe body over the entire circumferential direction, An outwardly facing annular groove that opens outward is formed on the outer peripheral surface of the inner pipe body over the entire circumferential direction, A C-shaped elastic ring is provided which elastically returns to its original position when the inward annular groove and the outward annular groove are aligned, and simultaneously engages with both of them; The outer tubular body has a notch formed in its outer peripheral surface, the notch communicating with the inward annular groove and having an axial width greater than the wire diameter of the C-shaped elastic ring, the cutout portion is composed of a cutout hole portion communicating with the inward annular groove and cutout surfaces of the outer pipe body located on both sides of the cutout hole portion in the circumferential direction, the cutout surface is an inclined surface that is cut out obliquely so as to form an acute angle with the annular bottom of the inward annular groove, A joint structure in which the open end of the C-shaped elastic ring can be exposed and pulled out through the cutout hole.

3. 3. The joint structure according to claim 1, wherein the notches are provided at a plurality of locations on the outer peripheral surface of the outer pipe.

4. 3. The joint structure according to claim 1, wherein the notch is shaped to open toward one end of the outer pipe in the axial direction.

5. 3. The joint structure according to claim 1, wherein the axial width of the inward annular groove of the outer pipe body or the outward annular groove of the inner pipe body is set larger than the wire diameter of the C-shaped elastic ring.

6. 3. The joint structure according to claim 1, wherein an airtight seal member is interposed between two opposing surfaces of the outer pipe body that are located farther back than the inward annular groove and closer to the open end than the outward annular groove of the inner pipe body.

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