JPH0643596Y2 - Flexible joint flange structure - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention is applied to pipes for sucking and discharging liquids and gases in factories and buildings, pipes for water and sewerage, etc. Vibration, noise absorption,
The present invention also relates to a flange structure of a flexible joint that controls various fluctuations such as vibration due to external force such as an earthquake.

[Prior Art] The conventional flange structure of the end portion of the flexible joint is roughly divided into four systems, a, b, c, and d, as shown in FIG.

a is a standard thick-walled flange structure in which the end of the flexible tube is joined to the inner diameter of the steel flange having standard dimensions such as outer diameter, plate thickness, center diameter of bolt hole, hole diameter, and number of holes. .

b is a fitting type flange part structure which is formed from the same standard size flange as a, but is formed by grinding the steel flange inner diameter part to form a fitting joint with the flexible tube end part.

c is a thin-walled flange structure in which a thin-walled flange made of steel in which only the plate thickness of the standard size flange is thinned and a gasket of a flexible tube are integrally joined.

d is a flange portion structure in which a flexible pipe is inserted and joined to a steel flange pipe in which a pipe is welded to a standard size flange.

As described in the characteristic comparison table of Table 1, the conventional four-system flange structure of a, b, c, d has different characteristics.

[Problems to be solved by the invention] By the way, as a flange structure of this kind of flexible joint, (a) it is lightweight, (b) the strength of the flange is large, and (c) the tightening of the gasket. The surface pressure is large and is uniform and durable. (D) A flexible joint between short surfaces including the flexible portion is formed. (E) The flexible portion can be firmly held. It is practically desired to satisfy the following five characteristics. However, as described above, it is impossible for the conventional technique to construct a device having all of these characteristics.

Then, this invention aims at providing the flange part structure of a flexible joint which can satisfy | fill all these five required characteristics simultaneously.

[Means for Solving the Problems] However, as a result of intensive studies to achieve the above-mentioned object, the shapes of the gasket and the thin-walled flange are specified, and these can be skillfully combined to mutually complement each other. The solution to this problem was found.

That is, this invention is a flexible joint in which a gasket is provided at both ends of a flexible tube, and a thin flange made of a steel plate is attached at a position facing the inside of the gasket, and a lower outer side of the gasket is provided. While protruding the curved seal portion on the end face, bend the lower part of the thin flange in the opposite direction,
A flexible joint characterized in that a bent portion is formed to connect with a flat portion having a bolt hole in a curved shape, and the flat portion of the thin flange excluding the bent portion and the gasket portion are closely contacted and joined. Related to the flange structure.

FIG. 2 is an explanatory view regarding the function of the flange portion structure of the flexible joint according to the present invention. In the figure, LF is a thin-walled flange made of steel plate, and a bent portion B in which a flat portion having a bolt hole H and its lower portion are bent in the opposing direction of both flanges.
By this bending, a reinforcing curved connecting body RCF is formed below the thin-walled flange LF by the cooperation of the flat sealing pressing portion A and the bending portion B.

PP is a flexible tube, which is mainly composed of rubber or an elastic polymer substance having rubber-like elasticity, and is composed of a flexible portion F, a thin flange and a gasket portion clamped between the mating flanges. The parts are considered to be more rigid than the flexible parts.

The sealing pressing portion A is a portion for pressing and sealing the curved sealing portion E projecting from the lower outer end surface of the gasket portion to the mating flange when the thin flange LF is fastened to the mating flange with a bolt.

The bent portion B is formed in a substantially cross-section shape so as to cover the outer peripheral portion of the flexible portion F without being adhered to both sides of the flexible portion F, and the boundary surface between the flange and the flexible portion is formed. The stress concentrated in the area is dispersed over a wide area to prevent the deformation of the lower part of the thin flange and to supplement the circumferential reinforcing performance of the reinforcing cord in the side part. Note that C is the thickness of the thin flange, and D is the width of the gasket portion of the flexible tube PP.

By the way, conventionally, a flexible joint made of an elastic body such as rubber as a main material has a fiber cord such as a interlaced weave as a reinforcing material against the internal pressure and is arranged inside in a state intersecting at least two directions. However, in order to increase the flexibility of the joint, one or several places in the center of the flexible part are often made spherical. In that case, the outer diameter of the spherical surface is larger than other parts. , Form of central fiber cord CCA (center cord angle) As shown in the center axis of flexible pipe AX
The cord angle α'intersecting with is larger than the cord angle α shown in the fiber cord form SCA (side cord angle) on both sides. That is, the cord has a large circumferential reinforcing property, and the cords have a small circumferential reinforcing property in both side portions.

The bent portion B has a role of complementing the circumferential reinforcement of the cord in the side portion, and the strength of the bent portion B is greater than that of the fiber cord. It is possible to sufficiently supplement the lack of strength.

Further, the crossed fiber cord having a small cord angle intersecting the long axis of the flexible tube tries to expand at both side portions in order to maintain the balance with the internal pressure when the internal pressure is applied. Therefore, when it is used under the condition that the internal pressure fluctuates greatly, the dimensions fluctuate greatly, causing early damage on both side portions. This tendency is generally greater as the flange diameter is smaller. In the flexible joint according to the present invention, the bent portion B configured as described above prevents such expansion variation and effectively suppresses breakage.

Further, the flange of the flexible joint according to the present invention has a lower portion which is supplementarily stabilized by the curved connecting body portion for reinforcement RCF, so that it is almost the same as the standard size flange despite being thin. Withstands bolt tightening pressure.

The curved seal portion E formed under the gasket portion is
It projects more than the upper part G of the gasket, and by pressing this projecting part first at the beginning of tightening, the surface pressure of the E part increases and a sufficient sealing pressure is generated between it and the mating flange. is there. Next, in the tightening stage of tightening, the upper part G of the gasket also comes into contact with the mating flange, and at this point the entire surface of the gasket comes into contact with the mating flange. This prevents tilting and bending.

Also, since the flat surface portion having the bolt holes of the thin flange and the gasket portion are joined by an adhesive, or they are joined closely by vulcanization adhesion, the sealing property between them is better than that of the fitting type flange portion structure. Is outstanding and contributes greatly to the improvement of holding power.

By using a thin flange and making the bent portion B non-bonded, the thickness (C + D) of the flange portion is reduced, and the length between joint surfaces (dimensions in the entire axial direction) can be shortened. The flexible portion can be set large. If the flexible portion is large, the allowable deformation amount is large, and if the length between the surfaces is short, there is an advantage that the mounting space can be reduced. Moreover,
It is lighter than a standard thick flange.

[Operation] As described above, according to the present invention, in the flange structure composed of the combination of the gasket and the thin flange, the curved seal portion is projected on the outer end surface of the gasket lower portion,
By bending the lower part of the thin flange, the gasket and flange can be complemented each other in strength and function.
At the same time as reducing the weight, the strength and sealing performance of the flange can be improved. Further, since the flat surface portion of the flange having the bolt holes and the gasket portion are adhered and joined by an adhesive treatment, a large holding force is exhibited as compared with the flange portion of the fitting system without deformation or peeling of the internal reinforcing fiber.

The bent portion at the lower portion of the flange complements the circumferential reinforcing property of the reinforcing cord on both sides of the flexible portion, and suppresses early damage due to expansion fluctuation of this portion.

Further, in this invention, since the flange is thin and the bent portion is in a non-bonded state, the joint surface can be shortened and the flexible portion can be set large.

As described above, according to the present invention, almost all of the problems of the conventional flange structure can be solved satisfactorily, and a flexible joint with superior performance can be obtained.

[Embodiment] FIG. 1 is a sectional view showing an example of a flange portion structure of a flexible joint according to the present invention.

In the figure, 1 is a thin-walled flange made of steel, and the lower part of the flat part having a bolt hole for tightening the flange is bent in the opposite direction of both flanges to connect the flat sealing pressing part 1a and the bent part 1b. The reinforcing curved connecting body RCF is formed to thereby form a thin-walled flange that is supplementally and stabilized in strength.

A flexible tube 2 is composed of a casket portion 2a and a flexible portion 2b, and a curved seal portion 2a (E) having a semicircular cross section is annularly projected on the lower outer end surface of the gasket portion 2a. ing. Reference numeral 3 is a fiber cord reinforcing layer arranged in a cross shape inside the flexible tube 2. The flexible portion 2b has a curved shape along the bent portion 1b, and is formed in a non-bonded state with the bent portion 1b. r ₀ is the outer radius r ₁ of the flexible portion 2b having a spherical shape between the opposing bent portions, and r ₁ is the same inner radius.

FIG. 4 is a cross-sectional view showing an example of a flange portion structure of a conventional flexible joint formed by using a thick flange having a standard size, which is used for a comparative example of a durability test. In the figure, 4 is a thick flange, 5 is a flexible tube, 5a is a gasket part, 5b is a flexible part, and 6 is a fiber cord reinforcing layer.

Next, an endurance test was conducted on the embodiment of the present invention shown in FIG. 1 and the comparative example shown in FIG. 4 by the following method.
In addition, in the new and old flexible joints used in this comparative test, the other configurations except for the flange portion, in particular, the dimensions, shape, material, reinforcing layer, etc. of the flexible portions 2b and 5b are the same for both. Is.

Endurance life measurement method: Following the general usage of flexible joints, the shaft deviation is set to 10 mm, blind flanges are attached to both ends of the joint, water pressure of 10 kg / cm ² is applied, and after holding for 10 seconds, 5 The pressure impulse that exhausted the pressure for ² seconds and the internal pressure was 0 kg / cm ² was repeated, and the number of times until failure was compared. The results are shown in Table 2.

As shown in Table 2, the flexible joint having the flange structure according to the present invention has a weight of 50% as compared with the flexible joint having the conventional structure.
% Reduction, and an improvement of about 20% in durability was achieved.

[Effects of the Invention] This invention specifies the shapes of the gasket and the thin-walled flange, and has a flange portion structure that can complement each other by combining them, so the weight is significantly reduced compared to the conventional product, And, a flexible joint having improved durability is provided.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a flange portion structure of a flexible joint of the present invention, FIG. 2 is an explanatory view showing the function of the present invention, and FIGS. 3A, 3B, 3C and 3D are, FIG. 4 is a cross-sectional view showing a conventional four-system flange portion structure, and FIG. 4 is a cross-sectional view showing an example of a conventional flange portion structure of a flexible joint using a standard-thickness flange. 1 ... Thin flange, 1a ... Seal pressing part 1b ... Bending part 2 ... Flexible tube, 2a ... Gasket part 2b ... Flexible part 3 ... Fiber cord reinforcing layer

Claims (1)

[Scope of utility model registration request] 1. A flexible joint comprising a flexible tube having gasket portions at both ends thereof, and a thin-walled flange made of steel plate provided at an inner facing position of the gasket portion, wherein a lower outer end face of the gasket portion is provided. A thin seal flange is formed by bending a lower portion of the thin-walled flange in an opposite direction while forming a curved seal portion in the opposite direction to form a bent portion that connects with a flat portion having a bolt hole in a curved shape, and excludes the bent portion. 2. A flange portion structure of a flexible joint, wherein the flat portion and the gasket portion are closely contacted and joined.