pipe fittings

Abstract

This invention provides a pipe connector capable of grounding during assembly. The pipe connector comprises: a connector disposed along an insertion space of a pipe body and having conductivity; a radially deformable sleeve disposed such that it surrounds the outer periphery of the aforementioned insertion space of the pipe body formed along the outer peripheral surface of the connector; a plurality of segmented retainers circumferentially covering the outer surface of the sleeve and disposed such that they can be separated radially; and a locking member disposed through the plurality of segmented retainers and causing the segmented retainers to move radially closer to each other such that the diameter of the sleeve is reduced. The conductive connector has a conductive grounding clamp in a manner that locks it at its outer periphery. The segmented retainers have retainer extensions extending in the pipe insertion direction longer than the length of the sleeve. As the plurality of segmented retainers are moved closer together by the locking member, the retainer extensions press the grounding clamp against the pipe body.

Description

Technical Field

[0001] The present invention relates to a pipe connection structure for dissipating static electricity generated in a pipe body such as a hose or a test tube due to the fluid, particles, powder passing through the pipe body or the friction between the pipe body and the object outside the pipe body. Prior Art

[0002] Conventionally, as a pipe connection structure that implements static countermeasures, there is the following: a pipe body with a flat outer surface and a strip of conductive carbon mixed therein is integrally fixed over its entire axial length, and a cap-type nut joint using a conductive material (sleeve) is assembled to provide a ground connection while preventing the hose from falling off or leaking (Patent Document 1). In particular, there is a case where a dedicated grounding clamp is used for grounding a large tube body that has a strip-shaped body mixed with conductive carbon in the axial direction and a reinforcing member protruding in a spiral shape along the outer surface (Patent Document 2).

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-36503 [Patent Document 2] Japanese Patent Application Laid-Open No. 2021-99138

[0004] The method described in Patent Document 1 allows for simultaneous grounding during fitting assembly, resulting in excellent workability. However, this is limited to relatively small hose diameters. Specifically, as the hose diameter increases, greater force is required to tighten the acorn nut, and the tool used also becomes larger, impairing workability. Furthermore, the sleeve often deforms or wears during fitting disassembly, resulting in an incomplete grounding connection upon reuse. The method described in Patent Document 2 can cope with a large hose diameter by using a clamp-type joint. However, when assembling the joint, the ground connection process must be performed separately, which makes it difficult to work with. Summary of the Invention

[0005] The present invention aims to solve these problems and to provide a pipe joint with good usability that can be grounded and connected at the same time as the joint is assembled without selecting the size or type of the pipe body.

[0006] To achieve these objectives, the present invention provides a pipe joint for connecting a conductive pipe body at the outer periphery or a partial area of ​​the outer peripheral surface, characterized in that it comprises: a joint arranged along the insertion space of the pipe body and having conductivity; a radially deformable sleeve arranged so as to surround the outer periphery of the insertion space of the pipe body formed along the outer peripheral surface of the joint; a plurality of split retainers circumferentially covering the outer surface of the sleeve on the outer side of the sleeve and arranged so as to be separable in the radial direction; and a locking member arranged through the plurality of split retainers and causing the split retainers to move radially toward each other in such a manner as to reduce the diameter of the sleeve, the conductive joint having a conductive grounding clamp in a state locked at its outer periphery, the split retainers having a retainer extension portion extending in the pipe insertion direction and being longer than the length of the sleeve, and the retainer extension portion firmly pressing the grounding clamp against the pipe body as the plurality of split retainers are moved toward each other by the locking member. [Effects of the Invention]

[0007] According to the present invention having the above-mentioned features, it is possible to provide a pipe joint that can be grounded while assembling the joint without selecting the size or type of the pipe body. Simple diagram description

[0008] [Figure 1] is an explanatory diagram showing the overall structure of a pipe joint according to an embodiment of the present invention. Figure 1(a) is a front view, Figure 1(b) is a top view, Figure 1(c) is a left side view, Figure 1(d) is an upper left perspective view, Figure 1(e) is a side sectional view of a sleeve as a component of the pipe joint, and Figure 1(f) is a perspective view of the sleeve. FIG. 2 is an explanatory diagram showing the overall structure of a pipe joint according to an embodiment of the present invention. FIG. 2( a ) is an exploded perspective view, FIG. 2( b ) is an assembled perspective view, and FIG. 2( c ) is an enlarged view of portion G of FIG. 2( a ). FIG3 is a side sectional view and a partially enlarged view showing the contact state between the pipe body and the grounding clamp. FIG. 4 is an explanatory diagram showing the steps of connecting a pipe joint and a pipe body according to an embodiment of the present invention, and is a diagram showing steps 1 to 3. FIG. 5 is an explanatory diagram showing the steps of connecting a pipe joint and a pipe body according to an embodiment of the present invention, and is a diagram showing step 4. FIG. 6 is an explanatory diagram showing the steps of connecting a pipe joint and a pipe body according to an embodiment of the present invention, and is a diagram showing steps 5 and 6. [Figure 7] is a diagram showing the shapes of the grounding clamp and spacer, which are components of the pipe joint according to an embodiment of the present invention. Figure 7(a) shows the shape of the grounding clamp in an upper perspective view, a side view, and a lower perspective view. Figure 7(b) shows other shapes of the grounding clamp in an upper perspective view, a side view, and a lower perspective view. Figure 7(c) shows the shape of the spacer in an upper perspective view, a side view, a front view, and a lower perspective view. [Figure 8] is an explanatory diagram showing the overall structure of a pipe joint according to another embodiment of the present invention, Figure 8(a) is a front view, Figure 8(b) is a top view, Figure 8(c) is a left side view, Figure 8(d) is an upper left perspective view, Figure 8(e) is a side sectional view of a sleeve as a component of the pipe joint, and Figure 8(f) is a perspective view of the sleeve. Implementation Method

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. (Structure of the pipe joint according to the embodiment) FIG1 is an explanatory diagram showing the overall structure of a pipe joint according to an embodiment of the present invention. FIG1(a) is a front view, FIG1(b) is a top view, FIG1(c) is a left side view, FIG1(d) is an upper left perspective view, FIG1(e) is a side sectional view of a sleeve, a component of the pipe joint, and FIG1(f) is a perspective view of the sleeve. FIG2 is an explanatory diagram showing the overall structure of a pipe joint according to an embodiment of the present invention. FIG2(a) is an exploded perspective view, FIG2(b) is an assembled perspective view of the exterior, and FIG2(c) is an enlarged view of section G of FIG2(a). A pipe joint A according to an embodiment of the present invention is used as follows: As shown in Figures 1(a) to 1(f) and Figures 2(a) to 2(c), a connecting end portion of a pipe body B having a conductive carbon wire BC and a reinforcing member projecting helically along its outer surface is inserted between a joint 1 and a radially deformable sleeve 2. A plurality of split retainers 3 are fitted around the outer side of the sleeve 2. A locking member 4 is used to move the split retainers 3 radially toward each other, connecting them into a cylindrical shape, while simultaneously grounding the pipe body B. By using a locking member 4 to move the multiple split retainers 3 closer together, the sleeve 2 is deformed to reduce its diameter, bringing the inner surface of the sleeve 2 into roughly uniform contact with the outer surface of the connecting end of the pipe body B throughout its entire circumference. Simultaneously, the inner surface of the pipe body B is brought into close contact with the outer circumference of the connector 1, creating a removable piping connection. This allows for simple connection even with relatively large-diameter pipes B, and facilitates assembly and disassembly, making it suitable for maintenance such as cleaning. Furthermore, this is more than just a simple connection. When the split retainers 3 are connected, the grounding clamp 5 secured to the outer circumference of the connector 1 contacts the conductive carbon wire BC of the pipe body B, establishing a grounding connection. If described in detail, the pipe joint A of the embodiment of the present invention has the following as main components: a joint 1, which is arranged along the insertion space of the pipe body B and has conductivity; a sleeve 2 that can be deformed in the radial direction, which is arranged in a manner surrounding the outer periphery of the insertion space of the pipe body B formed along the outer peripheral surface of the joint 1; a plurality of split retainers 3, which cover the outer surface of the sleeve 2 in the circumferential direction on the outer side of the sleeve 2 and are arranged in a manner that can be separated in the radial direction; a locking member 4, which is arranged through the plurality of split retainers 3 and causes the split retainers 3 to move radially closer to each other in a manner that reduces the diameter of the sleeve 2; a grounding clamp 5, which is locked on the outer periphery of the conductive joint 1 and has conductivity; and a retainer extension portion 33, which extends in the pipe insertion direction and is longer than the length of the sleeve 2. Furthermore, the insertion direction of the tube body B into the insertion space will be referred to as the "tube insertion direction" below, and the opposite direction of the tube insertion direction will be referred to as the "tube removal direction" below.

[0010] The fitting 1 is made of a rust-resistant metal such as stainless steel or brass, or a conductive resin material. It is formed into a thick, roughly cylindrical shape by cutting or casting, or by stamping or other forming processes. The side of the fitting 1 that connects to the pipe B is cylindrical, while the opposite side is shaped appropriately for connection to another pipe (not shown) or a pipe connection port (not shown) on another device. Specifically, cylindrical components such as a ferrule, thread, and bushing are integrally formed to facilitate connection to the other pipe.

[0011] The outer diameter of the joint 1 is formed to be substantially the same as the inner diameter of a pipe body B described later, or to be slightly larger or smaller than the inner diameter. The outer circumference of the connector 1 has, at predetermined axial locations, a concave-convex portion radially opposed to the inner surface of the sleeve 2, described later, across the insertion space for the tube B. This portion also features a flange 11, which serves as a retaining mechanism for restricting the position of the split retainer 3, described later, from axial movement. Furthermore, as shown in the partially enlarged view of Figure 2(c), two locking holes 12 are provided on the flange 11 (only one of which is shown in the partially enlarged view) for securing the grounding clamp 5, described later, to the connector. As a specific example of the joint 1, as shown in FIG2(a), in order to prevent the tube from falling off only at the front end portion (the end portion in the tube falling off direction) of the outer peripheral surface, a plurality of annular concave portions and annular convex portions are alternately formed in the axial direction. Furthermore, as another example, although not shown in the figure, changes can be made as follows: a bamboo shoot shape with alternating continuous annular recesses and annular protrusions in the axial direction is formed over approximately the entire length of the outer peripheral surface of the joint 1, or an annular sealing material is provided on the outer peripheral surface of the joint 1 to be radially pressed against the inner surface of the tube body B.

[0012] The sleeve 2 is formed from an elastically deformable material such as rubber or a soft synthetic resin into a generally cylindrical shape that is elastically deformable at least in the radial direction. The sleeve 2 is assembled to the outside of the outer circumference of the joint 1, radially opposing the outer surface of the connection end of the pipe B. During this assembly, the sleeve 2 has an inner surface that is mounted on the outside of the outer circumference of the joint 1 and radially opposes and contacts the outer surface of the connection end of the pipe B, and an outer surface that radially opposes the inner surface of a plurality of split retainers 3, described later. The inner surface of the sleeve 2 is designed so that its inner diameter, when expanded, is approximately the same as or slightly larger than the outer diameter of the tube body B, which will be described later, and so that its inner diameter, when reduced, is smaller than the outer diameter of the tube body B. Furthermore, as shown in FIG1(e), a spiral groove is formed on the inner surface of the sleeve 2 so as to correspond to the spiral shape of the reinforcing member protruding from the outer surface of the tube body B. Furthermore, the outer surface of the sleeve 2 is set so that its outer diameter, when expanded, is larger than its inner diameter when the multiple split retainers 3 have completed their approach movement, as described later. Specifically, the sleeve 2 is set so that its outer diameter is larger than the inner diameter of the inner surface of the multiple split retainers 3 when the multiple split retainers 3 have completed their approach movement and cannot move any further. Furthermore, it is preferable to form a structure as follows: by forming a plurality of cuts at predetermined intervals along the circumferential direction on the sleeve 2 for allowing it to elastically deform smoothly in the radial direction, sufficient inner diameter difference and outer diameter difference are generated during diameter expansion deformation and diameter reduction deformation. The elastic deformation is only applicable to the embodiment. Even if it is a solid or nearly solid object that can be deformed by tightening and assembled, it can be used as the sleeve 2 of the present invention.

[0013] The split retainer 3 is formed by circumferentially splitting a cylindrical body made of a rust-resistant metal such as stainless steel or brass, or a rigid material such as a hard synthetic resin, into a plurality of semi-cylindrical parts, as shown in Figure 2(a). Each of the split retainers 3 has a pair of circumferential end portions 31 with recessed portions 32 that are substantially parallel and opposed to each other. The plurality of split retainers 3, 3 are assembled so as to surround the outer surface of the sleeve 2 from the outside. In this assembled state, they have a plurality of circumferential end portions 31, 31 adjacent to each other in the circumferential direction and a plurality of inner side surfaces facing the outer surface of the elastic sleeve 2 in the radial direction. The peripheral end portions 31 of the plurality of split retainers 3, 3 are formed so that at least one pair of them protrude radially outward relative to each split retainer 3, and have end faces that are substantially parallel and opposed in the circumferential direction. Furthermore, the structure is such that even when the plurality of split retainers 3, 3 are in full contact, a gap exists between the opposing end faces. In other words, recesses 32 are provided in the opposing portions of each split retainer 3. The depth of the recesses 32 is set so that the spacers 6, described later, cannot be visually confirmed from the outside when the plurality of split retainers 3, 3 are in full contact. This serves as an indicator that the locking of the plurality of split retainers 3, 3 has been reliably completed. The plurality of split retainers 3, 3 have retainer extensions 33 that extend longer than the length of the sleeve 2 in the pipe insertion direction. As can be seen from Figures 1(c) and 1(d), the retainer extensions 33 are shaped so that the lateral portions in the figures extend longer than the upper and lower portions. During assembly, the upper and lower portions of the retainer extensions 33 abut against the abutment portions 53 of the grounding clamp 5, described later. Meanwhile, locking portions 34 are formed on the lateral portions of the retainer extensions 33, connecting to the lateral portions. These locking portions 34 engage with the flange 11 of the connector 1 in a manner that prevents axial movement. Furthermore, a locking member 4, described later, is provided through the peripheral end portions 31 of the plurality of circumferentially adjacent split retainers 3, 3. As can be understood from Figure 2(a), the structure is as follows: by operating the locking member 4, the plurality of split retainers 3, 3 are moved radially toward each other, thereby reducing the diameter of the sleeve 2. When the plurality of split retainers 3, 3 are moved toward each other by the locking member 4, the inner side surfaces of the plurality of split retainers 3, 3 are formed into a substantially circular arc surface, continuous with the inner side surfaces of the plurality of split retainers 3, 3. It is preferred to provide a step portion 35 on the inner side surface of each split retainer 3 for axially positioning the sleeve 2.

[0014] As shown in Figure 2(a), the locking member 4 is preferably a threaded component such as a bolt. This threaded component comprises a head 41 having a tool-engaging portion for engaging with a tool such as a wrench or spanner (not shown); a shaft 42 continuous with the head 41; and a threaded portion 43 formed at the distal end of the shaft 42. In the illustrated example, the tool-engaging portion is a hexagonal recessed portion. Furthermore, a washer is passed through the shaft 42. When a threaded part is used as the locking member 4, the threaded part is inserted through the through hole formed in one of the peripheral end portions 31 of the plurality of circumferentially adjacent split retainers 3, 3 and the threaded hole formed in the other. In this inserted state, a tool such as a wrench or a spanner is engaged with the tool engagement portion of the threaded part and rotated. This rotational operation causes the pair of split retainers 3, 3 to move radially toward each other, causing the sleeve 2 to deform and reduce in diameter. Furthermore, since it can be tightened with a relatively small tool such as a wrench or spanner, even a large-diameter pipe joint A for connecting a large-diameter pipe B can be easily connected. Furthermore, since it can be easily assembled and disassembled, it is also suitable for maintenance such as cleaning. As another example, although not shown, the following changes can be made: as the locking member 4, a bolt having a head with an outer peripheral surface formed into a polygon such as a hexagonal shape is used, or a locking part other than a screw part is used.

[0015] As shown in Figure 2(c), the grounding clamp 5, which is responsible for grounding the pipe B, consists of a roughly U-shaped portion 51, a protrusion 52, and an abutment portion 53. The roughly U-shaped portion 51 is inserted through the locking hole 12 of the connector 1 beforehand, securing the grounding clamp 5 to the connector 1. The roughly U-shaped portion 51 allows the grounding clamp 5 to move in the direction of pipe insertion. The protrusion 52 is configured to abut the conductive carbon wire BC of the pipe B, while the abutment portion 53 is configured to contact the retainer extension 33. In this embodiment, a tube B is assumed to be provided with a conductive carbon wire BC in the axial direction and a reinforcing member protruding helically along its outer surface. If the tube B is cut to adjust its length on site, the position of the conductive carbon wire BC initially emerging from the connection end of the tube B may vary in the longitudinal direction due to the shape of the reinforcing member protruding from it. To address this situation, the grounding clamp 5 is movable in the direction of tube insertion. Figure 3 shows a side cross-sectional view and a partially enlarged view of the contact between the tube B and the grounding clamp 5. It should be understood that regardless of the positional relationship between the connection end of the tube B and the protruding shape of the reinforcing member, the grounding clamp 5 can be moved so that the protrusion 52 contacts the conductive carbon wire BC of the tube B. Furthermore, the grounding clamp 5 is elastic. This elasticity ensures that the protrusion 52 securely contacts the conductive carbon wire BC of the tube B or the retainer extension 33 of the split retainer 3, making it less likely to fall off the connector 1. Furthermore, elastic deformation, rather than plastic deformation, also helps prevent breakage or wear during repeated use.

[0016] The spacers 6 are formed from a material such as polyacetal resin or another synthetic resin with excellent surface slip properties, and are used to suppress local bulging and deformation of the sleeve 2. As shown in Figure 2, a plurality of spacers 6 are disposed between the peripheral end portions 31 of a plurality of circumferentially adjacent split retainers 3, 3. Each spacer 6 has a guide surface 61 that radially faces and abuts against the remaining wall portion of the sleeve 2 that is deformed and reduced in diameter as the split retainers 3, 3 are moved closer together by the locking member 4. Furthermore, the spacers 6 have a through-portion 62 through which the locking member 4 passes. Furthermore, the spacers 6 may be composed of a solid material other than resin, such as metal. The guide surface 61 is formed on the inner side of the spacer 6 so as to be continuous with the inner side surfaces (arc surfaces) of the plurality of split retainers 3, 3. As shown in Figure 2, it is formed so that when locking is initiated with the locking member 4, the distance between the end surfaces of the circumferentially adjacent peripheral end portions 31 is wider. In other words, when locking is initiated with the locking member 4 shown in Figure 2, there is no gap between the circumferential ends of the guide surface 61 and the circumferential end edges of the inner side surfaces (arc surfaces) of the plurality of split retainers 3, 3. The through portion 62 can be a through hole as shown in Figure 2 or a spade-shaped notch or the like. The spacer 6 is colored in a conspicuous color such as red or fluorescent. As described above, when the multiple split retainers 3 are in full contact, the spacer 6 is completely contained within the recess 32 provided in the peripheral end portion 31 of the split retainer 3, making it invisible from the outside. Therefore, it is preferable to use a conspicuous color. Furthermore, the spacer 6, through its contact with the inner side surface (arc surface) of the split retainer 3 and the locking member 4 penetrating the penetration portion 62, restricts radial movement of the split retainer 3. Therefore, the spacer 6 does not protrude from the split retainer 3 and is reliably contained within the recess 32.

[0017] As described above, the tube B used in this embodiment is a tube B equipped with conductive carbon wires BC in the axial direction and a reinforcing member helically projecting along its outer surface. Specifically, the intermediate layer between the transparent or opaque outer and inner layers may include a laminated hose (braided hose) in which multiple or single synthetic resin braided wires (reinforcement wires) are helically embedded; a spirally reinforced hose in which a synthetic resin or metal strip-shaped reinforcing material (e.g., rectangular cross-section) and a linear reinforcing material (e.g., circular cross-section) are helically wound and integrated; or a spirally reinforced hose in which metal wires or rigid synthetic resin wires are helically embedded. Furthermore, a hose having a certain degree of transparency is advantageous in that it allows for precise identification of the conductive carbon wires BC and confirmation of the fluid passing through the tube B. However, even if the hose is opaque, there is no problem as long as the conductive carbon wires BC can be clearly distinguished by color.

[0018] (Connection Procedure of Pipe Joint of Embodiment) Next, the connection steps of the pipe joint according to the embodiment of the present invention will be described in detail based on Figures 4 to 6. Figures 4 to 6 show the connection steps of the pipe joint according to the embodiment of the present invention and the pipe body as steps 1 to 6. First, in step 1 shown in FIG. 4 , after the joint 1 and the pipe body B are prepared, the sleeve 2 is inserted into the connecting end of the pipe body B as shown in FIG. 4 . Next, in step 2 shown in Figure 4 , pipe B is inserted along the outer circumference of connector 1 in the pipe insertion direction. During insertion, grounding clamp 5 is aligned with the conductive carbon wire BC of pipe B (see the top view in step 2 of Figure 4 ), temporarily securing (positioning) grounding clamp 5. Next, in step 3 shown in FIG4 , a plurality of split retainers 3, 3, locking members 4, and spacers 6 are arranged so as to circumferentially cover the outer surface of the sleeve 2. In the figure, the retainer extension 33 of the split retainer 3 on the side with the through hole is arranged on the grounding clamp 5 side. However, since the split retainer 3 on the side with the threaded hole also has the retainer extension 33, grounding connection can be achieved even if the split retainers 3, 3 are reversed in their vertical positions. Next, in step 4 shown in Figure 5, use a hexagonal wrench to tighten the locking member 4 for temporary tightening. At this point, the split retainer 3 and the joint 1 are aligned in the pipe insertion direction. Specifically, as shown in the cross-sectional view II, the locking portion 34 of the split retainer 3 is engaged with the flange 11 of the joint 1. At this point, as shown in the left side view, the red color of the spacer 6 is easily visible from between the multiple split retainers 3, 3. Next, in step 5 shown in Figure 6, the locking member 4 is officially tightened, and the tube B is compressed with the sleeve 2. At this point, as shown in the left-hand side view and partial enlargement of step 5, the red color of the spacer 6 is still visible from between the multiple split retainers 3, 3. This indicates that tightening is incomplete. This indicates that the compression of the tube B by the sleeve 2 is insufficient, and regarding grounding, the protrusion 52 of the grounding clamp 5 is either in contact or not with the surface of the conductive carbon wire BC of the tube B. In other words, the conductivity is low. However, when the locking member 4 is used to move the multiple split retainers 3, 3 radially toward each other, causing the sleeve 2 to shrink and deform, a residual wall portion may be generated. This residual wall portion gradually expands radially or axially as the sleeve 2 subsequently shrinks and deforms, and the residual wall portion, with nowhere to go, bulges out between the peripheral ends 31 of the multiple circumferentially adjacent split retainers 3. However, the guide surface 61 of the spacer 6 radially abuts against the residual wall portion of the sleeve 2 from the outside, suppressing the bulging of the residual wall portion. The residual wall portion is guided circumferentially, preventing it from entering between the peripheral ends 31 of the multiple split retainers 3, 3. This prevents the residual wall portion of the sleeve 2 from biting into the peripheral ends 31 of the multiple split retainers 3, 3, allowing the multiple split retainers 3, 3 to be locked by the locking member 4. Finally, in step 6 shown in Figure 6, the locking member 4 is screwed in until the red color of the spacer 6 is no longer visible from the joint between the multiple split retainers 3, 3. As shown in the left-hand side view and its enlarged partial view of step 6, the red color of the spacer 6 is completely invisible from the surrounding area. This inability to visually identify the color of the spacer 6 provides a visual indication of the completion of the connection. In this state, the inner surface of the retainer extension 33 of the split retainer 3 is firmly pressed against the abutment 53, fully compressing the grounding clamp 5. By compressing the grounding clamp 5, the protrusion 52 of the grounding clamp 5 is firmly pressed against the conductive carbon wire BC of the tube B, ensuring good electrical conductivity. It can be understood that the spacer 6 serves the important function of indicating that the locking operation is complete.

[0019] As mentioned above, spacer 6 also has the important function of preventing the remaining wall of sleeve 2 from biting into split retainer 3. Specifically, the presence of spacer 6 prevents the sleeve 2 from loosening at the remaining wall and ensures uniform tightening of the sleeve 2 against the pipe B. This improves the resistance of the pipe B to break away from the connector 1, reliably preventing fluid leakage accidents and providing excellent safety. Furthermore, regardless of the wall thickness of the sleeve 2, it is possible to prevent the remaining wall from biting between the peripheral ends 31 of the plurality of split retainers 3, 3, thereby enabling the thick-walled sleeve 2 to further securely lock the tube body B. This further improves the resistance of the tube body B to falling out, and can reliably prevent fluid leakage accidents over a long period of time.

[0020] (Shapes of Components of the Pipe Joint of the Embodiment) The shapes of the grounding clamp and spacer, components of the pipe joint according to an embodiment of the present invention, will be described in particular. Figure 7(a) shows the shape of the grounding clamp in top, side, and bottom perspective views. Figure 7(b) shows another shape of the grounding clamp in top, side, and bottom perspective views. Figure 7(c) shows the shape of the spacer in top, side, front, and bottom perspective views. FIG7(a) shows the grounding clamp 5 described so far as an embodiment in its upper perspective, side, and lower perspective views. As described above, the grounding clamp 5 comprises a substantially U-shaped portion 51, a protrusion 52, and an abutment portion 53. The substantially U-shaped portion 51 is designed to have a significant length, at least one pitch of the reinforcing member projecting helically along the outer surface of the tube B. This ensures that the protrusion 52 of the grounding clamp 5, which is movable in the direction of tube insertion, consistently contacts the conductive carbon wire BC regardless of the circumferential position of the conductive carbon wire BC when the tube B is cut. Furthermore, the grounding clamp 5 is elastic. This elasticity ensures that the protrusion 52 firmly contacts the conductive carbon wire BC of the tube B. For reference, the grounding clamp 5 is shown slightly rightward between the side view and the lower perspective view, showing the grounding clamp 5 compressed by the retainer extension 33 of the split retainer 3. FIG7(b) shows an example of another shape of the grounding clamp 5 as shown in the upper perspective view, side view, and lower perspective view. The difference is that in the example of FIG7(a), the portion of the substantially U-shaped portion 51 extending from the protrusion 52 is inserted through the locking hole 12 of the connector 1. In contrast, in the example of FIG7(b), the bent portion of the substantially U-shaped portion 51 is inserted through the locking hole 12. The shape of FIG7(a) is less likely to fall out because the substantially U-shaped portion 51 from the end to the inside is inserted into the locking hole 12. However, the shape of FIG7(b) is more likely to fall out (although less likely to fall out) because the insertion portion is shallower than in FIG7(a). Whether it is more likely to fall out or more likely to fall out depends on the application, so the appropriate shape can be selected. Figure 7(c) shows the spacer 6 as an upper perspective view, a side view, a front view (arranged side by side), and a lower perspective view. As described above, the spacer 6 has a guide surface 61 that radially opposes and abuts the remaining wall portion of the sleeve 2, and a through portion 62 through which the locking member 4 passes. The opposite side of the guide surface 61 contacts the inner side (arc surface) of the split retainer 3. However, as shown in Figure 7(c), the wall thickness along the guide surface 61 is tapered, thicker in the center and gradually thinner toward the ends. The tapered portion slides as the multiple split retainers 3 are brought closer together using the locking member 4. This allows the spacer 6 to move smoothly radially inward relative to the locking member 4, reducing the tightening torque applied by the locking member 4. This results in excellent workability. For example, even a weak operator, such as a woman, can secure the split retainer 3 (completely secure it) using the locking member 4. When assembling the spacer 6, the shaft portion 42 and the threaded portion 43 of the locking member 4 are inserted through the through portion 62. However, after assembling the spacer 6, the inner diameter of the through portion 62 in the short-side direction is smaller than the maximum outer diameter of the head portion 41 and the threaded portion 43 of the locking member 4, and larger than the outer diameter of the shaft portion 42. Specifically, the spacer 6 is entirely formed of an elastically deformable material, and the inner diameter of the through portion 62 in the short-side direction is slightly smaller than the outer diameter of the threaded portion 43. This allows the through portion 62 to expand and contract in the short-side direction when the threaded portion 43 is inserted. In the illustrated example, the through portion 62 is formed into a tumbler-shaped structure consisting of a large circular portion slightly smaller than the outer diameter of the threaded portion 43 and a small circular portion approximately the same diameter as the outer diameter of the shaft portion 42.

[0021] (Structure of Pipe Joint of Other Embodiments) The embodiments described so far have used a tube B having conductive carbon wires BC in the axial direction and reinforcing members projecting helically along its outer surface. However, the present invention is also applicable to tubes B having a flat outer surface. Other embodiments involving tubes B having a flat outer surface will now be described. FIG8 is an explanatory diagram showing the overall structure of a pipe joint according to another embodiment of the present invention, wherein FIG8(a) is a front view, FIG8(b) is a top view, FIG8(c) is a left side view, FIG8(d) is an upper left perspective view, FIG8(e) is a side sectional view of a sleeve as a component of the pipe joint, and FIG8(f) is a perspective view of the sleeve. A pipe joint A according to another embodiment is used as follows: as shown in Figures 8(a) to 8(f), a connection end portion of a pipe body B having a conductive carbon wire BC is inserted between a joint 1 and a radially deformable sleeve 2. A plurality of split retainers 3 are placed outside the sleeve 2. The split retainers 3 are radially moved toward each other by a locking member 4 to form a cylindrical connection, simultaneously grounding the pipe body B. The pipe body B used in the pipe joint is a flat outer surface, lacking a spiral reinforcement member. By using a locking member 4 to move the multiple split retainers 3 closer together, the sleeve 2 is deformed and reduced in diameter, bringing the inner surface of the sleeve 2 into approximately uniform contact with the outer surface of the connecting end of the pipe body B throughout its entire circumference. Simultaneously, the inner surface of the pipe body B is brought into close contact with the outer circumference of the connector 1, creating a removable piping connection. This simplifies connection and allows for easy assembly and disassembly, making it suitable for maintenance such as cleaning. Furthermore, the connection is more than just a simple connection. When the split retainers 3 are connected, the grounding clamp 5 secured to the outer circumference of the connector 1 contacts the conductive carbon wire BC of the pipe body B, establishing a grounding connection. The inner surface of the sleeve 2 is designed so that its inner diameter when expanded is approximately the same as or slightly larger than the outer diameter of the tube body B, and so that its inner diameter when reduced is smaller than the outer diameter of the tube body B. Furthermore, as shown in FIG8(e) and FIG8(f), although grooves are formed on the inner surface of the sleeve 2 to facilitate deformation due to diameter reduction, the spiral grooves are not formed as in the previous embodiment. As can be understood from this, the only difference in the shape of the sleeve 2 in other embodiments is that the structure is exactly the same as that of the aforementioned embodiment.

[0022] While the pipe joint according to the embodiment of the present invention has been described in detail above with reference to the drawings, and its structure has been explained, the specific structure is not limited to these embodiments, and design modifications that do not depart from the spirit of the present invention are also encompassed by the present invention. For example, in the embodiment, it is readily understood that, because an elastically deformable sleeve is used, a spacer is provided to prevent the sleeve's residual wall from biting into the split retainer. However, if a solid sleeve with virtually no residual wall is used, the spacer is not necessarily required.

[0023] A: Pipe joint 1: Connector 11: Flange 12: Locking hole 2: Sleeve 3: Split cage 31: peripheral end 32: concave part 33: Cage extension 34: Stopper 35: Step 4: Locking member 41: Head 42: shaft 43: Threaded part 5: Grounding clamp 51: roughly U-shaped portion 52:convex part 53:Butt part 6: Spacer 61: Guide surface 62:Through B:tube body BC: Conductive carbon wire

Claims

1. A pipe fitting for connecting a conductive pipe body to the outer periphery or a portion thereof on the outer periphery of its outer surface, characterized in that it comprises: a fitting disposed along the insertion space of the pipe body and being conductive; a radially deformable sleeve disposed in such a way that it surrounds the outer periphery of the insertion space of the aforementioned pipe body formed along the outer periphery of the fitting; a plurality of split retainers circumferentially covering the outer surface of the sleeve and disposed in such a way that they can be separated radially; and a locking member disposed through the plurality of split retainers and moving the split retainers toward each other in such a way that the diameter of the sleeve is reduced, wherein the conductive fitting has a conductive grounding clamp in such a way that it is locked at its outer periphery, wherein the split retainers have retainer extensions extending in the pipe insertion direction that are longer than the length of the sleeve, and the retainer extensions press the grounding clamp against the pipe body as the plurality of split retainers are moved toward each other by the locking member.

2. The pipe fitting as described in claim 1, wherein, The aforementioned grounding clamp is elastic.

3. The pipe fitting as described in claim 2, wherein, The aforementioned grounding clamp consists of a generally U-shaped portion that can move along the tube insertion direction, a protrusion that abuts against the conductive portion of the aforementioned tube body, and an abutting portion that contacts the aforementioned retainer extension.

4. The pipe fitting as described in any one of claims 1 to 3, wherein, The aforementioned grounding clamp can move along the direction of pipe insertion.

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