JPH1163680A - Piping connection structure in hot water supply apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the cost in a piping connection structure for various hot water supply apparatus such as a hot water heater and a bath furnace by securely preventing packing from slipping out without use of another member. SOLUTION: An expanded femail part 1a is provided at an end of one piping 1 among a pair of left and right pipings 1, 2 where ends thereof are connected to each other, and a male part 2a inserted into the femail part 1a is provided at the end of the other end. In the mail part 2a there are formed in succession a straight pipe shaped expanded part 2e that makes surface contact with an internal surface of the femail part 1a over the entire length of the femail part lam toward an axial tip end side thereof, and a packing engagement part 2f having a smaller diameter than an outer diameter of the diameter expanded part 2e. A curvarture of a corner part 2h extending from the diameter expanded part 2e to the packing engagement part 2f is set to be smaller.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for connecting pipes for supplying hot and cold water in various hot water heaters such as a hot water heater and a bath kettle.

[0002]

2. Description of the Related Art Conventionally, as this kind of pipe connection structure, a structure shown in FIGS. 7 and 8 has been provided.

In the structure shown in FIG. 7, one of a pair of left and right copper pipes 1 and 2 which are butt-connected to each other (right side in the figure) has a female section 1a having an enlarged diameter and a female section. Flanges 1b projecting outward in the radial direction are formed at the tip of 1a.

The other (left side) pipe 2 is provided with a male portion 2a inserted into the female portion 1a.

[0005] The male portion 2a is moved back and forth along the axial direction.
Raised portion 2b raised in the radial direction by flare processing,
A packing 4 such as an O-ring and a backup ring 6 for preventing the packing 4 from coming off are both fitted between the raised portions 2b and 2c.

Further, a connection fitting 8 is externally fitted and fixed to the other pipe 2 at a position opposed to the backup ring 6 with the raised portion 2b interposed therebetween, and the connection fitting 8 and the flange portion 1b of one pipe 1 are connected. Both pipes 1 and 2 are integrally fixed by screws 10 and connected.

In the structure shown in FIG. 7, the protruding portions 2b and 2c for preventing the packing 4 from escaping are formed by pressing the distal end portion of the pipe 2 along the axial direction. In the formation, it is difficult to accurately process the outer diameters of the raised portions 2b and 2c so as to substantially match the inner diameter of the female portion 1a, and to make the raised portions 2b and 2c protrude greatly toward the female portion 1a. When the bending is increased, problems such as cracking at the portion occur.

Therefore, each of the raised portions 2b and 2c is
The bend is made small so that it does not protrude too much to the a side, but when doing so, each raised part 2b, 2c and the female part 1a
A gap will be created between the inner surface of the first member and the second member.

In this state, if the packing 4 is simply provided between the two raised portions 2b and 2c, the packing 4 is moved to the left raised portion 2b in the figure when the internal pressure is applied to the pipes 1 and 2.
May escape through the
Backup ring 6 having an outer diameter substantially matching the inner diameter of
Is provided to prevent the packing 4 from slipping out and prevent water leakage.

Next, in the structure shown in FIG. 8, one of the pair of left and right pipes 1 'and 2' which are butt-connected to each other (one on the right side in the figure) is provided with an expanded female part 1 '. 'a is formed.

The other (left side in the figure) pipe 2 'is provided with a male portion 2'a inserted into the female portion 1'a.

The male portion 2'a is formed with a bulge 2'b and a bulge 2'c sequentially in the axial direction, and the bulge 2'b
The auxiliary metal fitting 7 is fitted to the support member 7, and the packing 4 is externally fitted between the auxiliary metal fitting 7 and the raised portion 2'c.

[0013] The outer surface of the male portion 2'a of the other pipe 2 'is fixed by screws 10 inserted through the inner and outer surfaces of the female portion 1'a of the one pipe 1'. The pipes 1 'and 2' are connected.

Also in this configuration, the raised portion 2'c for preventing the packing 4 from escaping is provided, and the auxiliary metal fitting 7 prevents the packing 4 from coming off when internal pressure is applied, so that water leakage does not occur. I have to.

[0015]

In the construction shown in FIGS. 7 and 8, the backup ring 6 and the auxiliary metal fitting 7 are provided to prevent the packing 4 from coming off. Providing the separate member 6 or 7 separately for 1, 2, or 1 ', 2' not only requires an extra step, but also requires that the separate members 6, 7 are always stocked, thus reducing the cost. There is a problem that comes up.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to reliably prevent the packing from coming off without using a separate member, thereby achieving a cost reduction as compared with the related art. Make it an issue.

[0017]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention solves the above-mentioned problem by providing an expanded female portion at one end of a pair of left and right pipes whose ends are connected to each other. But,
The following configuration is adopted in a pipe connection structure in which a male section inserted into the female section is provided at an end of the other pipe.

That is, in the present invention, the male portion has a straight tube-shaped enlarged portion that comes into surface contact with the inner surface of the female portion over a predetermined length toward the tip end in the axial direction, and the male portion has a larger diameter than the outer diameter of the enlarged portion. Also, a small-diameter packing fitting portion is sequentially formed, and a curvature of a corner portion from the enlarged-diameter portion to the packing fitting portion is set to be small.

[0019]

FIG. 1 is a sectional view showing a piping connection structure in a hot water supply apparatus according to an embodiment of the present invention, and portions corresponding to the prior art shown in FIG. 7 are denoted by the same reference numerals.

The piping connection structure shown in FIG. 1 has an expanded female diameter at one end (right side in the drawing) of a pair of left and right pipes 1 and 2 whose ends are connected to each other. A flange portion 1b protruding radially outward is formed at the tip of the portion 1a and the female portion 1a.

A male part 2a inserted into the female part 1a is provided at an end of the other (left side in the figure) pipe 2.

The male part 2a in this embodiment has an enlarged diameter part 2e, a packing fitting part 2
f, and an outwardly bent portion 2g are sequentially formed.

The enlarged diameter portion 2e is formed in a straight tube substantially matching the inner diameter of the female portion 1a so as to make surface contact with the inner surface of the female portion 1a over a predetermined length F. 2f is formed in a straight tube having a diameter smaller than the outer diameter of the enlarged diameter portion 2e.

Then, from the enlarged diameter portion 2e to the packing fitting portion 2f.
The curvature of the corner portion 2h is set to be small enough to be substantially perpendicular to the two portions 2e and 2f.

Further, a connection fitting 8 is externally fitted to a position opposed to the packing 4 with the enlarged diameter portion 2b interposed therebetween.
And the flange 1b of one of the pipes 1 are integrally fixed by screws 10, and the two pipes 1 and 2 are connected.

In the configuration shown in FIG. 1, the enlarged diameter portion 2e
Is in surface contact with the inner surface of the female portion 1a for a certain length F, and the corner portion 2h is substantially perpendicular to the packing fitting portion 2f. Therefore, even when an internal pressure is applied, the packing 4 is connected to both pipes 1h. , 2 does not get out of between the two pipes 1 and 2, and water leakage can be reliably prevented. Therefore, the conventional backup ring 6 can be omitted.

Next, a method of forming the male portion 2a of one pipe 2 used in this connection structure will be described with reference to FIG.

A straight pipe 2 is prepared, and the pipe 2
After fitting the fitting 8 (not shown in FIG. 2) in advance, the mold 22 is press-fitted from the end face of the pipe 2 to expand one end of the pipe 2 (FIG. 2A, (See (b)).

Subsequently, after the mold 22 is pulled out, the rotating die 24 is brought into contact with and pressed against the enlarged diameter portion of the pipe 20 and the outer periphery of the non-diametered portion of the pipe 20, thereby swaging the enlarged diameter portion 2e. (See FIG. 2 (c)).

Next, a bent portion 2g is formed using the split mold 26 and the pressing mold 28 (see FIG. 2D).

In addition to the embodiment shown in FIG. 1, a piping connection structure shown in FIG. 3 can be adopted.

The structure shown in FIG. 3 corresponds to the structure of the conventional example shown in FIG. 8, and the parts corresponding to those of the prior art shown in FIG.

In this embodiment, the male part 2'a of the pipe 2 '
Has a structural feature.

That is, the male portion 2'a in this embodiment has an enlarged diameter portion 2'e, a packing fitting portion 2'f, and a raised portion 2'c formed in that order toward the tip end in the axial direction. It becomes.

The above-mentioned enlarged diameter portion 2'e is brought into surface contact with the inner surface of the female portion 1'a over a predetermined length F '.
The packing fitting portion 2'f has a smaller diameter than the outer diameter of the enlarged diameter portion 2'e and has an arc-shaped cross section so that the packing 4 'is fitted therein. Is formed.

The curvature of the corner portion 2'h from the enlarged diameter portion 2'e to the packing fitting portion 2'f is set to be small enough to be substantially orthogonal to the two portions 2'e and 2'f. .

In the configuration shown in FIG. 3, as in the case of FIG. 1, the enlarged diameter portion 2'e comes into surface contact with the inner surface of the female portion 1'a for a certain length F 'and the corner portion 2' Since 'h is in a state substantially perpendicular to the packing fitting portion 2'f, even when an internal pressure is applied, the packing 4' comes out from between the two pipes 1 'and 2', or both the pipes 1 'and 2'. It is possible to reliably prevent water leakage without being caught between the two. Therefore, the conventional auxiliary fitting 7 can be omitted.

In the embodiment shown in FIG. 1, a bent portion 2g for preventing the packing 4 from escaping is provided at the tip side of the male portion 2a of the pipe 2, but instead, as shown in FIG. A configuration in which a straight tubular flare portion 2i having substantially the same outer diameter as the diameter portion 2e may be provided.

In the embodiment shown in FIGS. 1 and 2, the diameter of the pipes 2 and 2 'is increased to increase the diameter of the enlarged diameter portions 2e and 2e.
2′e, but as shown in FIGS. 5 and 6,
If the entire outer diameter of the male pipe 2 ″, 2 ′ ″ is the same as the inner diameter of the female section of the other pipe (not shown), the packing fitting section 2 ″ f , 2 '''f are formed with a smaller diameter than the other parts, and the packing fitting portions 2''f,
The outer peripheral part close to 2 '''f is used as it is as the enlarged diameter part 2''e,
It is also possible to adopt a configuration of 2 ″ ′ e.

[0040]

According to the present invention, the packing can be reliably prevented from coming off by integrally forming the pipe without using a separate member such as a conventional backup ring or auxiliary metal fitting. Thus, the cost can be further reduced as compared with the related art.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a pipe connection structure in a hot water supply apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory view showing a method of forming a male part in the pipe connection structure of FIG. 1 in the order of steps.

FIG. 3 is a sectional view showing a pipe connection structure according to another embodiment of the present invention.

FIG. 4 is a sectional view showing a pipe connection structure according to another embodiment of the present invention.

FIG. 5 is a sectional view showing a pipe connection structure according to another embodiment of the present invention.

FIG. 6 is a sectional view showing a pipe connection structure according to another embodiment of the present invention.

FIG. 7 is a sectional view showing a piping connection structure in a hot water supply device according to a conventional example.

FIG. 8 is a sectional view showing a pipe connection structure in a hot water supply device according to another conventional example.

[Explanation of symbols]

1, 1 '... piping, 1a, 1'a ... female part, 1b ... flange part, 2, 2' ... piping, 2a, 2'a ... male part, 2e, 2'e,
2''e, 2 '''e ... enlarged diameter part, 2f, 2'f, 2''f, 2''' f ...
Packing fitting part, 2h, 2'h ... corner part, 2g ... bending part,
2'c: raised portion, 2'c: flare portion.

Claims (1)

[Claims] 1. A female part having an enlarged diameter is provided at an end of one of a pair of right and left pipes whose ends are connected to each other.
In a pipe connection structure in a water heater in which a male part inserted into the female part is provided at an end of the other pipe, the male part is provided on an inner surface of the female part toward an axial front end side. A straight-tube enlarged-diameter portion that makes surface contact over the length,
A packing fitting portion having a diameter smaller than the outer diameter of the enlarged diameter portion is sequentially formed, and a curvature of a corner portion from the enlarged diameter portion to the packing fitting portion is set to be small. Piping connection structure in hot water supply equipment.