JP2009002498A - Expansion joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To invent the assembling mechanism in an expansion joint to retain a bigger diameter than the diameter of an inlet and an outlet of the expansion joint. <P>SOLUTION: The space part for sliding is prepared on the inner circumference of the first pipe member which is placed to the outside of an expansion joint and a groove is established on the outer circumference near the end of the second pipe member which is placed on its inside. Next, an insertion hole is prepared on the groove or the space part for sliding and the groove is prepared with a retaining member such as a steel ball, a contact coil spring capable of bending freely from this insertion hole and so on. Finally, the plug is set to the insertion opening if required. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention belongs to an expansion pipe joint for piping.

  The conventional flange-type expansion joint has a problem that the inner diameter of the flange connected to the pipe differs between the inlet and outlet flanges, and the larger inner diameter is larger than the inner diameter of the gasket to be used, and the required inner diameter of the gasket is not reached. was there.

  In addition, the conventional threaded expansion joints have different nominal diameters of pipe threads connected to the pipes at the inlet and outlet. From the viewpoint of pipe threads with larger nominal diameters, the inner diameter of the expansion pipe joint and the other pipe thread There was a problem that was too small.

  The cause of this problem lies in the assembly of the retaining member for the expansion joint. The cause and problem will be described below by taking the expansion pipe joint disclosed in Japanese Patent Laid-Open No. 9-112772 as an example. The structure is shown in FIG. The inner diameter of the connection flange 38 welded to the first pipe member 35 is larger than the inner diameter of the gasket seat (plane portion) of the flange 44 welded to the second pipe member 36. The cause is the assembly of the retaining member 46. The retaining member 46 is necessary so that the expansion joint is not separated, but the retaining member 46 is fitted into the groove 45 with the groove 45 of the second tube member protruding from the connection flange 38 during assembly. For this purpose, the inner diameter of the flange 38 must be larger than the outer diameter of the retaining member 46. Since the outer diameter of the retaining member 46 is larger than the outer diameter of the second pipe member 36, the inner diameter of the connection flange 38 is larger than the outer diameter of the second pipe member 36.

  On the other hand, since the inner diameter of the gasket is substantially the same as the outer diameter of the second pipe member 36, the inner diameter of the connection flange 38 is larger than the inner diameter of the gasket. As a result, there is a problem that the gasket does not come into contact with the flange near the inner diameter, and the contact width of the leakage stopper is reduced.

  FIG. 2 shows a case where the flange of the expansion joint of FIG. 1 is a groove type (the center portion is omitted), but the groove G1 has a larger inner diameter of the flange 38 when the groove G1 and the groove G2 of the connection flange are compared. Therefore, it does not become a complete groove like the groove G2. As a result, there was a problem that it could not be used as a groove type.

  In the case of a screw-type expansion joint, the nominal diameter of the pipe thread is determined based on the above-mentioned flange inner diameter, so that the nominal diameters of the inlet and the outlet are different, which has the problem described in [0003].

  Inventing a mechanism for assembling a stopper having a diameter larger than the inlet diameter and outlet diameter of the expansion pipe joint inside the expansion pipe joint.

  A sliding space is provided on the inner periphery of the first pipe member that comes outside the expansion joint, and a groove is provided on the outer periphery near the end of the second pipe member that comes inside. Next, an insertion hole is provided in the groove or the space for sliding, and a retaining member such as a steel ball or a contact coil spring that can be freely bent from the insertion hole is attached to the groove. Finally, plug the insertion slot if necessary.

  Since the connecting portion with the pipe of the expansion joint and the retaining portion are independent, both can be determined freely. As a result, not only the problems of conventional products can be solved, but also flanges, screws, housing joints, welding and the like can be used for connection to the pipe. Moreover, since the diameter of the retaining portion can be increased, the inner diameter is increased, the flow resistance can be decreased, and the performance is improved. Furthermore, the use of standard parts such as steel balls and close coil springs and the ease of assembly reduce costs. As these comprehensive effects, the expansion joint suitable for the use can be manufactured at low cost.

  FIG. 3 shows the basic structure of the present invention, and FIG. 4 shows an enlarged view of portion A in FIG. FIG. 3 shows a welded structure of the first pipe member 35 and the connection flange 38 and the second pipe member 36 and the connection flange 44 of FIG. This outline means that a welded structure as shown in FIG. 1 or an integral structure by casting may be used. An O-ring 47 is fitted in the O-ring collecting groove 39, and a dust seal 48 is fitted in the dust seal collecting groove 40. This portion has the same structure and function as in FIG.

  G1 and G2 are grooves provided in the connection flanges 38 and 44. The inner diameter of the connection flange 38 is made small so that the groove G1 becomes a complete groove. The slide space 43 is a wide groove provided on the inner periphery of the first tube member 35. There is a groove 45 on the outer periphery of the distal end of the second pipe member 36, and many steel balls B46 are fitted therein. The steel ball B46 is inserted from the insertion hole H49 formed in the groove 45, and a plug 50 (see FIG. 4) is inserted when the groove 45 is almost full so that the steel ball B46 does not come off. . The stopper 50 is fixed by an appropriate method such as adhesion, screwing or press fitting.

  Because of this structure, the second pipe member can move left and right in the sliding space 43 with the steel ball B46 fitted in the groove 45. FIG. 3 shows a state in which the second pipe member moves to the left and stops when the steel ball B46 hits the left wall of the sliding space 43. When the steel ball B46 moves to the right, it stops against the right convex portion. . The steel ball B46 prevents the second pipe member from coming off from the first pipe member 35, and determines the amount of expansion and contraction of the expansion joint.

  The steel ball B46 described above may be replaced with a resin ball having high strength, and the ball may be shaped like a short cylinder or wine barrel. In short, it is sufficient that the steel ball and other retaining members have strength, can be inserted from the insertion hole H49, and have a shape whose direction is stable in the groove 49.

  In the above example, the steel balls and the like are separated one by one, but it is also possible to use a steel ball or the like that is made like a necklace by making a hole in the steel ball or the like and passing a freely bending wire.

  As another practical example, there is a method using a contact coil spring. A close contact coil spring S46 having the same outer diameter as the steel ball B46 is inserted from the insertion hole H49 by utilizing the bending of the close contact coil spring S46. The close contact coil spring S46 is straight before insertion, but is bent along the sliding space 43 after insertion, and therefore does not naturally come out of the insertion hole H49. Therefore, the plug 50 is unnecessary. Since the plug 50 is not necessary, the insertion hole 49 can be formed into a long hole. If the oblong shape is long in the direction perpendicular to the paper surface of FIG.

  FIG. 5 shows a screw-type expansion joint. Ends of the first pipe member 35 and the second pipe member 36 are cut with pipe screws T1 and T2 having the same nominal diameter. The internal structure and function are the same as in FIGS.

  When the nominal diameter of the screw-in type expansion joint is small, the inner diameter of the second pipe member 36 is small, and the plug 50 is difficult to close. There are two ways to deal with this. The method is shown in FIGS. In FIG. 6, a coil spring C50 is fitted inside the insertion hole H49. This coil spring C50 prevents the steel ball B46 from coming off. The coil spring C50 is fitted so as to be slightly reduced in diameter or provided with a groove as shown in FIG. 6 so as not to move from the position of the insertion hole H49. Further, instead of the coil spring 50, a C-shaped spring, a concentric snap ring for holes, or the like may be used.

  FIG. 7 shows another method. First, the groove 45 is provided in the second pipe member, and the insertion hole H52 is provided in the slide space 45 of the first pipe member 35. Next, the insertion hole H52 and the groove 45 of the second pipe member 36 are aligned at the same position, and a retaining member such as a steel ball B46 and a close coil spring S46 is inserted. Finally, the insertion hole H52 is sealed with a plug P53 or the like.

Conventional expansion joint Explanatory drawing when a conventional expansion pipe joint is a grooved flange Flange type expansion joint of the present invention Part A enlarged view of FIGS. 3 and 5 Threaded expansion joint of the present invention Another embodiment of part A Partial enlarged view with an insertion hole in the slide space

Explanation of symbols

35: 1st pipe member 36: 2nd pipe member 38, 44: Connection flange G1, G2: Groove of groove type flange 42: Protruding part 43: Space part for slide 45: Groove B46: Steel ball S46: Contact coil spring H49 : Insertion hole C50: Coil spring H52: Insertion hole P53: Plug

Claims (1)

  A slide space is provided on the inner periphery of the first pipe member that is located outside the expansion joint, and a groove is provided on the outer periphery near the end of the second pipe member that is located on the inside, and an insertion hole is provided in this groove or the slide space. An expansion tube joint characterized by mounting a retaining member such as a steel ball or a tightly coiled coil spring that can be bent freely through the insertion hole and plugging the insertion port if necessary.

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