JP2005090605A - Piping connector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To air-tightly or liquid-tightly connect pipes-to-be connected by using a connector with a small number of parts items. <P>SOLUTION: The connector is provided with a pair of flanges 1 having a through hole 6, an annular sleeve 2 arranged between the pair of flanges 1 and fixed to each of the flanges 1, a gasket 3 arranged between the pair of flanges 1 inside the annular sleeve 2 to abut on the peripheral surface 5 of the connection pipe 4 arranged inside the through hole 6 of the flange 1, a fastening member 9 for fastening a pair of seat parts 8 formed near a fitting part 7 of each of the flanges 1, and a tooth part 10 provided inside the flange 1 forming the through hole 6. The tooth part 10 is pushed onto the peripheral surface 5 of the connection pipe 4 by fastening the fastening member 9 to make the tooth part 10 bite the peripheral surface 5, and while the gasket 3 is air-tightly or liquid-tightly pinched between the peripheral surface 5 of the connection pipe 4 and the annular sleeve 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a pipe joint that connects a pair of connection pipes, and particularly to a pipe joint that connects a pair of connection pipes called a headless pipe or a plain end pipe that is not subjected to machining, welding, or coating.

  A conventional pipe joint for connecting a headless pipe is, for example, a flexible telescopic pipe joint for embedding for water pipe connection that aims to improve the ability of preventing the disconnection of the connection pipe shown in Patent Document 1 and Patent Document 2 below, It is roughly classified into so-called strub type pipe joints used for repairing existing pipes shown in Patent Documents 3 and 4 below and housing type pipe joints shown in Patent Document 5.

Japanese Patent No. 2547707 Japanese Utility Model Publication No. 1-150291 Japanese Patent No. 1629577 Japanese Patent No. 1629578 Japanese Utility Model Publication No. 36-23287

  The embedded flexible telescopic pipe joint shown in FIGS. 6 to 9 is used to connect a connection pipe such as a water pipe formed of a vinyl chloride pipe or a normal carbon steel pipe. This embedded flexible telescopic pipe joint (50) includes a joint body (51), a rubber gasket (52) disposed between the joint body (51) and the connecting pipe (4), and a gasket. A push ring (53) for pressing (52) against the joint body (51), a retaining ring (54) having a substantially C-shape and fixed to the connecting pipe (4), and a retaining ring (54) A fixing member (55) for fixing to the main body (51), and a bolt (56) and a nut (57) for fastening the retaining ring (54) to the connecting pipe (4) are provided. On the inner surface of the retaining ring (54), a locking tooth (58) that contacts the outer peripheral surface (5) of the connection pipe (4) is formed, and when the bolt (56) and the nut (57) are fastened, the retaining ring (54) is reduced in diameter, the locking teeth (58) bite into the outer peripheral surface (5) of the connecting pipe (4), and the connecting pipe (4) is detached from the flexible telescopic fitting (50) for burial. Is blocked. The fixing member (55) is a T-shaped bolt (63) inserted into a through hole (61) formed in the flange (60) of the joint body (51) and a through hole (62) formed in the push ring (53). ) And a nut member (66) inserted into a through hole (65) formed in the retaining ring (54) and connected to a T-bolt (63). When the nut member 66 is tightened with respect to the T-bolt 63 from the state before tightening shown in FIG. 8 to the state after tightening shown in FIG. 9, the press ring 53 is connected to the joint by the nut member 66. It moves toward the flange (60) of the main body (51) .For this reason, the pusher wheel (53) presses the gasket (52) toward the outer peripheral surface (5) of the connecting pipe (4) to form a sealing structure. The The retaining ring (54) fixed to the connecting pipe (4) can move in the axial direction along the cylindrical portion (67) of the nut member (66) by the length of the cylindrical portion (67).

  Since the retaining ring (53) is mainly formed of ductile cast iron, the hardness of the locking tooth (58) which is only about 200 to 250 Vickers hardness is low, and the number of teeth of the locking tooth (58) is also large. The bite load per tooth is small. On the other hand, since the connecting pipe (4) is usually formed of stainless steel having an outer peripheral surface hardness of Vickers hardness of 200 to 250, the locking teeth (58) are connected to the outer peripheral surface (5 of the connecting pipe (4)). ) And only the frictional force between the teeth of the locking teeth (58) and the outer peripheral surface of the connection pipe (4) prevents the connection pipe (4) from slipping out. For this reason, when the internal fluid flows in the connecting pipe (4) at a pressure of 4 Mpa (megapascal) or more, if the inner diameter of the connecting pipe (4) becomes larger than a certain value, the connecting pipe (4) is completely detached from the fitting. It has been confirmed by experiments that a so-called “slip-out” phenomenon occurs. Further, since the engaging teeth (58) made of ductile cast iron and the connecting pipe (4) made of stainless steel make different metal contacts, there is a concern about the occurrence of corrosion in a wet environment such as when buried.

  Further, when a plurality of nut members (66), for example, four nut members (66) are fastened to the T-shaped bolt (63), a plurality of nuts are resisted against the elastic repulsion force of the gasket (52) formed of thick rubber. The member (66) must be alternately and repeatedly tightened, and the gasket (52) must be sufficiently deformed to establish a fluid sealing structure with surface pressure. In the example shown in the drawing, the total number of bolts including the bolts (56) for fastening the locking teeth (58) is 10 per one pipe joint, and much work man-hours must be spent for fastening the bolts. In addition, as shown in FIG. 7, when a pipe joint is attached to the wall (67) or on the floor (68), the wall (67) or the floor (68) surface is obstructed and the bolt (56) or There is also a nut (57), so the workability is very bad.

  The strub type pipe joint (70) shown in FIGS. 10 and 11 is mainly used for repairing existing pipes. The strub type pipe fitting (70) is arranged in the housing (71) at the end of the housing (71), the elastomer seal sleeve (72) arranged in the housing (71), and the seal sleeve (72). Snap ring (73), frustum-shaped spring ring (74) disposed in contact with snap ring (73) and seal sleeve (72), bent end (75) of housing (71), A support ring (76) disposed between the frustum-shaped spring ring (74) and a pair of tongues (77) extending outward from the housing (71) and welded to the outside of the housing (71) And a bolt (78) for connecting the tongue piece (77). After assembling the strub fitting (70), fully insert the connecting pipe (4) from both sides and tighten the bolt (78) .The frustum-shaped spring ring (74) bites into the outer surface of the connecting pipe (4). Thus, the connection pipe (4) can be prevented from slipping out, and at the same time, the sealing sleeve (72) is pressed against the outer peripheral surface (5) of the connection pipe (4) to form a sealing structure with the connection pipe (4). In the strub type pipe joint (70), by tightening the bolt (78), the diameter of the housing (71) is reduced, and at the same time, the pressure-compressed seal sleeve (72) forms a self-sealing structure and a frustum-shaped spring ring ( Since 74) bites into the outer peripheral surface (5) of the connecting pipe (4), the number of bolts to be tightened is small and the workability is good. `` Self-sealing structure '' refers to a sealing structure formed by utilizing the pressure of fluid flowing in the connecting pipe (4), and the sealing sleeve (72) having a self-sealing structure is connected to the connecting pipe (4) with a large compressive force. A given sealing function can be obtained without pressing the outer peripheral surface (5).

  However, since a clearance is provided between the inner diameter of the frustum-shaped spring ring (74) and the outer peripheral surface (5) of the connecting pipe (4) when the pipe is inserted, the frustum-shaped spring ring (74) is bent. Rotate the bolt (78) many times to compress the seal sleeve (72) so that it finally comes into contact with the outer peripheral surface (5) of the connection pipe (4) with a predetermined pressing force over the clearance, deflection, and interval. There is a need to. For example, since the amount of axial movement of the bolt (76) reaches 20 to 30 mm for tightening with a predetermined pressing force, for example, for tightening a bolt (78) having a screw pitch of 1.5 mm, 13 to 20 rotations are necessary, and workability is poor. The frustum-shaped spring ring (74) is formed from a thin plate of a cold-rolled steel plate made of stainless steel having a Vickers hardness of 400 to 500 higher than the outer peripheral surface (5) of the connecting tube (4) made of stainless steel. The hardness of the spring wheel (74) depends on work hardening during cold rolling. Therefore, as disclosed in Patent Document 3 and Patent Document 4, even if various improvements are made to the ability of the frustum-shaped spring ring (74) to bite into the outer peripheral surface (5), the frustum manufactured from a thin plate is used. The trapezoidal spring ring (74) has insufficient rigidity. For example, the frustum-shaped spring ring (74) bites into the outer peripheral surface of the connecting pipe (4) during construction, but if a stainless steel pipe with a diameter of about 100 mm or more is subjected to a high pressure of about 4 MPa (megapascal) on the internal fluid The tip of the frustum-shaped spring ring (74) to bite into the outer peripheral surface (5) of the connecting pipe (4) due to a slight movement in the tube axis direction due to the load in the disengagement direction is plastically deformed, and the tooth tip Experiments have revealed that the sharp tip of is lost. For this reason, the tooth tip cannot be bitten, and the tightening torque and the disengagement preventing force of the bolt (78) are reduced, leading to the tube removal.

  In addition, the strub type pipe joint (70) manufactured by pressing stainless steel thin plate and spot welding cannot be used for complex joint shapes, so it is limited to the type that connects the connection pipe (4) on the same axis. In order to connect the elbow-type or tee-type connection pipe (4), as shown in FIG. 12, a plurality of strub-type pipe joints (70) are connected via elbows (77) or tee parts separately prepared as shown in FIG. Because the connection pipe (4) is connected by this, the construction cost increases.

  The housing type pipe joint (80) shown in FIGS. 13 and 14 includes a pair of half-shaped joint bodies (81), an annular gasket (82) disposed in the joint body (81), and a joint body ( 81) and a bolt (87) for tightening the retaining member (85) fitted in the groove (84) formed in the edge (83) and the flange (86) formed at both ends of the joint body (81). And a nut (88). When connecting the pair of connection pipes (4) which are headless pipes by the housing type pipe joint (80), the retaining member (85) is made of a tooth tip formed of hardened carbon steel having a Vickers hardness of 600 to 700. Have. The teeth of the retaining member (85) sufficiently bite into the outer peripheral surface (5) of the connecting pipe (4) made of stainless steel, approximately 8MPa (megapascal) equivalent to almost twice that of the strub type pipe joint (80) Experiments have shown that this produces the ability to prevent tube detachment. However, when connecting the stainless steel connection pipe (4) in a wet environment with the housing-type fitting (80), it is due to the dissimilar metal contact between the carbon steel teeth and the stainless steel connection pipe (4). There is concern about the occurrence of corrosion. Further, as shown in FIG. 13, in the housing type pipe joint (80), the joint body (81) having a halved shape is fastened by the bolt (87) supported by the flange (86). There are disadvantages in that the weight of the main body (81) increases and the workability of tightening bolts on the wall or on the floor deteriorates.

  Further, since the housing type pipe joint (80) is attached to the connecting pipe (4) from the disassembled state of the gasket (82) and the retaining member (85), the workability is poor. In addition, due to structural limitations limited to the socket type that connects the connecting pipe (4) held on the same axis, the housing type pipe fitting (80) alone cannot be applied to the elbow type or cheese type connecting pipe. There is.

  Then, an object of this invention is to provide the pipe joint which can connect a connection pipe airtightly or liquid-tightly with few components. An object of this invention is to provide the pipe joint which can join the headless pipe | tube with high surface hardness like the stainless steel pipe | tube which does not have the possibility of corrosion by a dissimilar metal contact. An object of the present invention is to provide a pipe joint having a tooth portion having a high bite force and a small number of tightening bolts and good workability. SUMMARY OF THE INVENTION An object of the present invention is to provide a pipe joint that has a separation preventing structure that can withstand from low pressure to high pressure and a sealing performance, and that is highly reliable and can be manufactured at low cost.

  The pipe joint according to the present invention is disposed between a pair of flanges (1) each having a through hole (6) and a joint (7) formed in communication with the through hole (6), and the pair of flanges (1). And an annular sleeve (2) fixed to each flange (1), and disposed between the pair of flanges (1) inside the annular sleeve (2) and disposed in the through hole (6) of the flange (1). Tighten the gasket (3) in contact with the outer peripheral surface (5) of the connected pipe (4) and the pair of seats (8) formed near the joint (7) of each flange (1) in a direction approaching each other. A tightening member (9) and a tooth portion (10) provided inside the flange (1) forming the through hole (6) are provided. Before assembling the pipe joint and tightening the fastening member (9), insert the end of the connection pipe (4) into the through hole (6) of each flange (1), and connect the outer peripheral surface (5 The gasket (3) is brought into contact with the outer peripheral surface (5) of the connecting pipe (4) outside the gasket (3). After that, by tightening the tightening member (9), the tooth portion (10) is pressed onto the outer peripheral surface (5) of the connecting pipe (4), and the tooth portion (10) is bitten into the outer peripheral surface (5). The gasket (3) is sandwiched between the outer peripheral surface (5) of the connecting pipe (4) and the annular sleeve (2) in an airtight or liquid tight manner.

  A pipe joint can be easily attached to the connecting pipe (4).

Hereinafter, an embodiment of a pipe joint according to the present invention will be described with reference to FIGS.
The pipe joint according to the first embodiment of the present invention shown in FIGS. 1 and 2 includes a pair of flanges (1) having a through hole (6) and formed in a C shape in a symmetrical shape, and a pair of flanges (1). An annular sleeve (2) disposed between the flanges (1), a gasket (3) disposed between the pair of flanges (1) inside the annular sleeve (2), and a joint (7 ) A tightening member (9) that tightens a pair of seats (8) formed integrally with each flange (1) in the vicinity of each other, and an inner side of the flange (1) that forms the through hole (6) And a tooth portion (10) provided on the surface. Each flange (1) includes a joint (7) formed in communication with the through hole (6), an outer protrusion (1a) formed radially inwardly on the axially outer side of the flange (1), and A central protrusion (1b) formed radially inward at the substantially axial center of the flange (1), and an inner protrusion (1c) formed radially inward on the axially inner side of the flange (1). The outer annular recess (1d) formed between the outer projection (1a) and the central projection (1b), and the inner annular recess (1e) formed between the central projection (1b) and the inner projection (1c). ) And a notch (1f) formed between the central protrusion (1b) and the inner annular recess (1e).

  The annular sleeve (2) has a cylindrical tube portion (11) and flanges (12) formed by extending radially outward at both ends of the tube portion (11). The inner surface of the cylindrical portion (11) abuts on the gasket (3), and the flange portion (12) is disposed in the inner annular recess (1e) of the flange (1). The annular sleeve (2) contacts the inner surface of (1) and is fixed to each flange (1). The inner peripheral surface of the gasket (3) contacts the outer peripheral surface (5) of the connection pipe (4) disposed in the through hole (6) of the flange (1). The flange portion (12) of the annular sleeve (2) is locked to an inner protrusion (1c) formed to protrude radially inward from the flange (1).

  The gasket (3) includes an annular main body (20) that contacts the annular sleeve (2), a connecting portion (21) protruding radially inward from both ends of the annular main body (20), and each connecting portion (21). A lip (22) that protrudes inward and abuts on the outer peripheral surface (5) of each connecting pipe (4), fits into the notch (1f) of the flange (1) and protrudes axially outward from the connecting part (21) And an annular lug (23). The tightening member (9) includes a bolt (13) that is inserted into a through hole formed in the seat (8), and a nut (14) that is screwed to the bolt (13). By tightening the bolt (13) and the nut (14), the pair of seats (8) is moved in a direction approaching each other, whereby the flange (1) is reduced in diameter together with the teeth (10), and the connecting pipe The tooth portion (10) is pressed radially inward against the outer peripheral surface (5) of (4).

  Before assembling the pipe joint in the temporarily tightened state and tightening the fastening member (9), insert the end of the connection pipe (4) into the through hole (6) of each flange (1), and connect the connection pipe (4). The gasket (3) is brought into contact with the outer peripheral surface (5), and the tooth portion (10) is brought into contact with the outer peripheral surface (5) of the connection pipe (4) outside the gasket (3). Thereafter, by tightening the fastening member (9), the flange (1) is reduced in diameter together with the connecting portion (21) of the gasket (3), and the annular lug (23) of the gasket (3) is attached to the flange (1). The cutout (1f) is pressed radially inward toward the outer peripheral surface (5) of the connection pipe (4). For this reason, the annular body (20) of the gasket (3) is pressed radially inward by the annular sleeve (2), so the annular lug (23) forms the initial seal structure, and the gasket (3) It is sandwiched between the outer peripheral surface (5) of the connecting pipe (4) and the annular sleeve (2) in an airtight or liquid tight manner, and the final fastening is completed. At the same time, the tooth portion (10) pressed against the outer peripheral surface (5) of the connection pipe (4) bites into the outer peripheral surface (5), and the connection pipe (4) is prevented from coming off from the pipe joint. The When the pressurized fluid flows in the connecting pipe (4), the pressurized fluid contacts the inner surface of the gasket (3) from between the pair of connecting pipes (4). The pressure of the fluid presses the annular body (20) of the gasket (3) outward, and simultaneously presses the lip (22) against the outer peripheral surface (5) of the connecting pipe (4). ) In addition to the initial seal structure, the pressure of the fluid flowing in the connection pipe (4) is used to form a `` self-sealing structure '' that provides a sealing structure. A given sealing function can be obtained without pressing the outer peripheral surface (5) of 4). Therefore, it is not necessary to compress and deform the gasket (3) to the outer peripheral surface (5) of the connecting pipe (4) with a large compressive force.

  The tooth portion (10) is formed of stainless steel with a shape having two claw portions (10a) that bite into the outer peripheral surface (5) of the connecting pipe (4), and the outer peripheral surface of the stainless steel connecting pipe (4) (5 ) Having a Vickers hardness of 500 or more, greatly exceeding the Vickers hardness of 200 to 250. For this reason, the tooth portion (10) is formed of austenitic stainless steel that has undergone special carburizing, nitriding or cold work hardening. In addition, in the state before diameter reduction when the connecting pipe (4) is inserted, the clearance between the outer peripheral surface (5) of the connecting pipe (4) and the tooth portion (10) can be set to about 1 mm in diameter, so that the tightening member If the bolt (13) or nut (14) of (9) is rotated 2-3 times, the tightening operation is completed in a short time.

  FIG. 3 shows a second embodiment of the pipe joint according to the present invention using a retaining member having a V-shaped cross section as the tooth portion (10). This retaining member is also made of stainless steel having a Vickers hardness of 500 or more, like the tooth portion (10) shown in FIG.

  4 and 5 show a third embodiment of the pipe joint according to the present invention. The bolt (14) inserted into the through hole (15) formed in the flange (1) is screwed to the screw hole (16) of the annular sleeve (2), thereby connecting the flange (1) and the annular sleeve (2). An example of fixing is shown. Four bolts (14) are provided on the same circumference, and the diameter of the non-threaded portion of the bolt (14) is made larger than the diameter of the screw hole (16) of the annular sleeve (2). ) And the annular sleeve (2) is provided with a clearance (17). Further, the through hole (15) of the flange (1) is formed with a long hole elongated in the circumferential direction or a diameter larger than the diameter of the bolt (14), and a clearance is formed between the through hole (15) and the bolt (14). (18) can be provided to absorb the difference in deformation between the flange (1) and the annular sleeve (2). The bolt (14) can be attached to the annular sleeve (2) in a tightened state in advance, or can be attached at a construction site. The gasket (3) need not be integrally formed, and may be divided into two parts corresponding to each flange (1) as shown in FIG. Since the gasket (3) divided into two parts also has a U-shaped cross section, a self-sealing action can be obtained by the pressure of the internal fluid. Further, the tooth portion (10) is not a separate body but is integrally formed on the inner surface of the flange (1).

In the embodiment of the present invention, the following operational effects are obtained.
[1] When tightening the bolt (13) and nut (14), the flange (1) and tooth (10) can be reduced in diameter on the same plane perpendicular to the central axis of the connecting pipe (4). A large pressing force can be applied to the tooth portion (10) against the outer peripheral surface (5) of the connecting pipe (4).
[2] The flange (1) on both sides individually and at the same time as the flange (1) and the toothed portion (10), the annular sleeve (2) is also reduced, so that the outer peripheral surface (5) of the connecting pipe (4) In contrast, the diameter of the gasket (3) can be reduced or pressed.
[3] A self-sealing gasket can be used to reduce the number of bolts (13) to which pipe fittings are attached.
[4] The sealing performance at low pressure can be improved by the initial compression given to a part of the gasket (3).
[5] By fastening each flange (1) individually with individual bolts (13), the inserted connecting pipe (4) is held coaxially with respect to each flange (1) and against the gasket (3). It can prevent per piece.
[6] The connecting portion (4) made of stainless steel having a high surface hardness can easily bite the tooth portion (10) having a high hardness.
[7] The possibility of the occurrence of corrosion due to the contact of different metals with the stainless steel pipe can be eliminated.
[8] Since the annular sleeve (2) with a short axial length can be used, the overall length of the pipe joint can be shortened. May be.
[9] By using an elbow-shaped or T-shaped annular sleeve (2), it is possible to cope with a curved pipe section and a branch section.

  The present invention is particularly effective for a pipe joint that connects a pair of connection pipes called a headless pipe or a plain end pipe.

Sectional drawing which shows 1st Embodiment of the pipe joint by this invention Side view of FIG. Partial sectional view showing a second embodiment of the tooth portion Sectional drawing which shows 3rd Embodiment of the pipe joint by this invention Side view of FIG. Sectional view of a conventional flexible expansion joint for embedding Side view of the flexible expansion joint for embedment of FIG. 6 showing the state of being attached to the wall and on the floor Partial sectional view of the flexible expansion joint for embedment of FIG. 6 in a temporarily tightened state Partial sectional view of the flexible expansion joint for embedment of FIG. 6 in the final tightened state Sectional view of a conventional strub joint Side view of the strobed joint of FIG. Cross-sectional example showing the fitting state of the strab joint fitting Side view of housing type fitting Sectional drawing which follows the 14-14 line of FIG.

Explanation of symbols

  (1) ・ ・ Flange, (2) ・ ・ Annular sleeve, (3) ・ Gasket, (4) ・ ・ Connection pipe, (5) ・ ・ Outer surface, (6) ・ ・ Through hole, (7) ・· Joint, (8) · · Seat, (9) · · Tightening member, (10) · · Tooth, (11) · · Tube, (12) · · buttock, (13) · · Bolt , (14) ・ ・ Nut, (15) ・ ・ Through hole, (16) ・ ・ Screw hole, (20) ・ Annular body, (21) ・ ・ Connecting part, (22) ・ Lip, (23) ..Ring lugs,

Claims (7)

  A pair of flanges each having a through hole and a joint formed in communication with the through hole, an annular sleeve disposed between the pair of flanges and fixed to each flange, and disposed between the pair of flanges inside the annular sleeve A gasket that contacts the outer peripheral surface of the connection pipe disposed in the through hole of the flange, a tightening member that tightens a pair of seats formed near the joint of each flange in a direction approaching each other, and a through hole And a tooth portion provided on the inner side of the flange to be formed, and by pressing the tooth portion onto the outer peripheral surface of the connection tube by tightening the fastening member, the tooth portion is bitten into the outer peripheral surface, and at the same time, the outer periphery of the connection tube A pipe joint characterized in that a gasket is sandwiched between a face and an annular sleeve in an airtight or liquid tight manner.   The pipe joint according to claim 1, wherein each flange is formed in a C shape with a symmetrical shape.   3. The pipe joint according to claim 1, wherein the annular sleeve has a cylindrical portion that contacts the gasket, and a flange portion that is formed to extend radially outward at both ends of the cylindrical portion and contacts the inner surface of the flange.   The pipe joint according to any one of claims 1 to 3, wherein the flange portion of the annular sleeve is locked to an inner protrusion formed so as to protrude radially inward from the inside of the flange or is fixed to the flange with a bolt.   The tube according to any one of claims 1 to 4, wherein the flange is reduced in diameter together with the tooth portion by tightening of the tightening member, and the tooth portion is pressed radially inward with respect to the outer peripheral surface of the connection tube. Fittings.   The flange is reduced in diameter together with the connecting portion of the gasket by tightening of the tightening member, and the gasket is pressed radially inward against the outer peripheral surface of the connecting pipe. Pipe fittings.   The gasket includes an annular body that abuts on the annular sleeve, a coupling portion that projects radially inward from both ends of the annular body, a lip that projects inward from each coupling portion and abuts on the outer peripheral surface of each connecting pipe, and a coupling portion The pipe joint according to any one of claims 1 to 6, further comprising an annular lug that protrudes outward in the axial direction and is pressed radially inward by the flange.

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