JP2707056B2 - Heat exchanger for water heater and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger for a water heater, in particular, a heat absorbing section in which a number of fins are juxtaposed in a can body, and a water supply pipe section following the heat absorbing section is attached to the can body surface. TECHNICAL FIELD The present invention relates to a heat exchanger for a water heater having a bypass circuit that bypasses a heat absorbing section between an inlet side and an outlet side of a water supply pipe, and a method for manufacturing the same.

[0002]

2. Description of the Related Art As shown in FIGS. 1 and 2, a heat exchanger for a water heater is provided with fins (F) and (F) at a predetermined interval at an open upper end of a can body (1) formed in a substantially rectangular tube. And water supply pipes (2) are penetrated therethrough in a meandering manner to form a heat absorbing portion.
Then, the inlet side pipe (21) of the heat absorbing section is wound around the body of the can body (1), and the outlet side pipe (22) is wound on the portion where the inlet side pipe (21) is wound from the heat absorbing section. Hanging alongside.

In this type of heat exchanger, the inlet side pipe (2
The downstream end of the water supply device (not shown) is connected to the connection end (23) of 1), and the upstream end of the circuit to the hot water supply faucet is connected to the connection end (24) of the other outlet side pipe (22). Used in a connected manner. A combustion device is built in the lower portion of the can body (1) .When water is supplied from the connection end (23) in a state where the combustion device is burned, combustion heat is mainly emitted from the fins (F) and (F) of the heat absorbing portion. Absorbed
Heat is exchanged with the water in the water supply pipe (2).

In recent heat exchangers of this type, the generation of drain at the fins (F) and (F) disposed in the heat absorbing portion is prevented by maintaining the temperature of the heat absorbing portion at a certain temperature or higher. Like that. For this purpose, a so-called bypass heating method is adopted, and as shown in FIG.
(22a) and the connecting pipe (33) that forms the bypass circuit (3), and the surface temperature of the fins (F) and (F) of the heat absorbing portion drops below a certain temperature when the heat exchange amount is small. I try not to let them.

[0005] However, when the bypass circuit having the conventional configuration is mounted, there is a problem that the work of mounting the bypass circuit (3) is very troublesome. In the above-mentioned conventional type, the connecting pipe is used to construct the bypass circuit (3).
It is necessary to connect both ends of (33) to the opening (21a) and the opening (22a) in an airtight manner by brazing or the like, and the opening (21a)
This is because it is necessary to bend the communication pipe (33) into a predetermined shape in advance in accordance with the position of the opening (22a).

In the prior art, the inlet pipe (21) and the outlet pipe (22) of the water supply pipe (2) are respectively connected to the intermediate connecting portions (210) and (210) near the lower end of the can body (1). At 220), it is connected to the tip side piping section by brazing. And
Normally, at the junction between the main circuit of the water supply pipe (2) wound around the can body (1) and the can body (1) and the fins, after assembling both of them, the brazing material is placed at a predetermined position. Then, it is brazed by heating in a heating furnace, and thereafter, a brazing connection is performed on a tip side pipe portion below the intermediate connection portions (210) and (220), and an opening is formed with the communication pipe (33). (21a) and the joint with the opening (22a) are brazed. Therefore,
There is an inconvenience that the work of brazing the connecting pipe (33) must be performed separately from the work of brazing the can (1) and the fin and the water supply pipe (2) to the main circuit.

[0007] The present invention has been made in view of such a point, and is described as follows. "A number of fins (F) (F) are juxtaposed in a can body (1), and a water supply pipe (2) is connected thereto. The inlet pipe (21) and the outlet pipe (22) of the water supply pipe (2) are attached to the surface of the can body (1), and the inlet pipe (21) and the outlet pipe ( 22), a heat exchanger for a water heater with a bypass circuit (3) formed between the heat exchanger and the heat exchanger, so that the structure of the bypass circuit (3) can be simplified and the heat exchanger can be made inexpensive. An object of the method is to improve workability of a brazing operation.

[About the invention of claim 1]

[0009]

[Technical Means] The technical means of the present invention for solving the above problems is that "the upstream part of the inlet side pipe (21) and the downstream part of the outlet side pipe (22) are formed on the surface of the can body (1). An opening (21a) and an opening (22a) are formed in the water supply pipe forming wall of the overlapping portion, and the openings (21a) are fixed so that the openings coincide with each other.
a) (22a) The communication port (31) formed between the two is used as the bypass circuit (3). "

[0010]

The above technical means operates as follows. The pipe walls of the inlet side pipe (21) and the outlet side pipe (22) are overlapped with each other, and the openings (21a) and the openings (22a) formed in these pipe walls are fixed so as to coincide with each other, and the inlet side pipe is fixed. (21) to the exit side pipe (22)
A bypass circuit (3) is formed. Therefore, unlike the related art, there is no need to separately prepare a connecting pipe (33) bent in accordance with the openings (21a) and the openings (22a) at distant positions.

Since the communication port (31) is formed in such a manner that the opening (21a) and the opening (22a) are directly overlapped,
By arranging the brazing material in the overlapped portion and heating, the periphery of the opening is securely brazed, and the airtightness of the connecting portion can be secured.

[0012]

According to the present invention having the above configuration, the following specific effects are obtained. Since there is no need to separately prepare the connecting pipe (33), the configuration for the bypass circuit (3) is simplified, and the material cost is lower than that of the conventional one that uses the connecting pipe (33) of a certain length. Can be saved and inexpensive.

A communication port corresponding to a bypass circuit (3)
Since the length of the flow path of (31) is extremely short, the bypass circuit (3)
Side resistance is small. Therefore, compared with the conventional system using the communication pipe (33), a sufficient bypass flow rate can be secured even if the diameter of the communication port (31) is reduced. [Regarding the invention of claim 3] The invention of claim 3 is a method of manufacturing the heat exchanger of the invention of claim 1, and the technical means employed for this purpose is described in "Inlet side pipe (21)". The upstream part of the pipe and the downstream part of the outlet pipe (22) are overlapped on the surface of the can body (1), and the opening (21a) and the opening (22
a) and caulking with a ring body (32) so that these openings coincide with each other, and then the inlet side pipe (21)
A brazing material is disposed at a joint between the outlet pipe (22) and the surface of the can body (1), and a brazing material is disposed at a joint at the periphery of the openings (21a) and (22a). A step of heating to a predetermined temperature in the state and brazing is provided ”, and in the heat exchanger that has undergone the brazing step, each part connected to the parts or each part joined or opposed is joined in a brazed state. Thus, the heat exchanger according to the first aspect of the present invention is configured.

[Others] In the first aspect of the present invention, if the opening (21a) and the opening (22a) are overlapped and caulked by the ring body (32), the opening (21a) Since the overlapping portion with the opening (22a) does not shift, brazing failure is less likely to occur when brazing by heating in a heating furnace using a brazing material.

[0015] In the invention according to claim 3, the "inlet side pipe"
The distance from the upstream open end of the (21) to the opening (21a) and the distance from the downstream open end of the outlet pipe (22) to the opening (22a) are such that the caulking tool can be inserted from the open end. Set to
The step of caulking the openings (21a) (22a) with a ring body (32) includes the step of caulking inserted from the upstream open end of the inlet pipe (21) and the downstream open end of the outlet pipe (22). Process with a tool for caulking ”, the inlet side pipe (2
The ring body (32) can be precisely and reliably caulked by the caulking tool inserted from 1) and the open end side of the outlet pipe (22), and the workability of this work is good.

[0016]

Next, an embodiment of the present invention will be described in detail with reference to the drawings. In the embodiment shown in FIGS. 3 to 7, a copper can
(1) The copper pipe fins (F) (F), which are arranged side by side at regular intervals at the open end of (1), penetrate the copper pipe water supply pipe (2) at the inlet side pipe (21) of the copper pipe water supply pipe (2). The upstream end and the downstream end of the outlet pipe (22) are orthogonal to each other.

Specifically, the connection end (23) of the inlet side pipe (21)
A predetermined range on the downstream side is set in the horizontal direction, and a certain range on the upstream side from the connection end (24) of the outlet pipe (22) is set in the vertical direction, and the horizontal range of the inlet pipe (21) is set. Direction part and outlet side pipe
The vertical part of (22) is vertically overlapped on the surface of the can body (1). As shown in FIG. 5, an opening (21a) is formed on the inlet side pipe (21) side of the polymerization section, and the other outlet side pipe (2) is formed.
An opening (22a) is formed on the 2) side. The diameters are set to be the same, and the inlet-side pipe (21) side and the outlet-side pipe (22) side are caulked using the ring body (32).

The ring body (32) is, as shown in FIG.
One end of the short cylindrical body is provided with a flange (32a). The opening (21a) of the pipe wall of the inlet pipe (21) is formed as shown in FIG.
As shown in (1), the opening (21a) is formed in advance in the center of this flat portion by being partially flattened by press molding. Similarly, the other opening (22a) is also formed at the center of the partially flattened tube wall, and the tube wall of the inlet side tube (21) and the outlet side tube (22) is arranged so that these flat portions are in contact with each other. Each other is superimposed.

The distance from the open end of the connection end (23) to the opening (21a) and the distance from the open end of the connection end (24) to the opening (22a) are set relatively short. You. For example, when the inlet side pipe (21) and the outlet side pipe (22) are copper pipes having an outer diameter of 14 mm, the distance is set to about 30 mm. Then, as shown in FIG. 5, the ring body (32) is inserted into the opening (21a) and the opening (22a) from the upper inlet side pipe (21), and is inserted into the lower outlet side pipe (22). Protrude. At this time, the flange (3
2a) is in contact with the periphery of the opening (21a) in the inlet side pipe (21). In this state, connect one of the caulking molds (K ₁ ) to the connection end.
(23) into the inlet side pipe (21) and the other crimping mold
(K ₂ ) is inserted from the connection end (24) into the outlet tube (22), and caulking is performed using these dies.

As a result, the end of the body of the ring body (32) projecting into the outlet side pipe (22) is flared, and the periphery of the opening (21a) is located between the flared part and the flange part (32a). The portion and the peripheral portion of the opening (22a) are crimped in a state of being pressed. (Refer to the imaginary line in the figure.) Normally, the main part of this type of heat exchanger consists of a can body (1), fins (F) (F), and a water supply pipe (2). ) Are straight pipes (21b) penetrating the fins (F), (F), U-shaped connecting pipes connecting the ends of these straight pipes (21b), an inlet pipe (21) and an outlet pipe. (twenty two)
Consists of

Each joint is brazed in a state where these parts are connected or assembled. In this brazing step, the brazing material is arranged in each joint and in the vicinity thereof, and the whole is heated. Put in the furnace. For example, opening (21
a) In order to braze the peripheral wall of (22a), as shown in FIG. 5, a brazing material (R) curved in a C-shape is interposed in this portion. As shown in FIG. 7, between the fins (F) and (F) and the straight pipe (21b) serving as the water supply pipe (2), the straight pipe (21b) of the fins (F) and (F) is provided. Insertion hole for inserting
(H) A bar-shaped brazing material penetrating through the notches (A) and (A)
(R) will be installed.

Usually, a tunnel furnace is used as the heating furnace. Then, while passing through the heating furnace, the brazing material is melted and penetrates into the fitting portion and the joining portion between the components due to the surface tension and the wetting action at this time. Thereafter, the cooling operation completes the brazing operation. The heat exchanger manufactured in this manner is connected to the outlet pipe (22) from the connection end (23) of the inlet pipe (21) through the heat absorbing section provided with the fins (F) and (F).
From the connecting end (23) to a part of the inlet side pipe (21) and the outlet side pipe (22) through the communication port (31).
And a short circuit reaching the connection end (24) from a part of the connection end.

When a predetermined piping portion of the water heater is connected to the connection ends (23) and (24), the water heater functions similarly to the above-described water heater. In this embodiment, the opening (21a) and the opening (22a) are crimped by the ring body (32), but may be temporarily fixed by another method and then brazed. As the ring body (32), as shown in FIG. 8, annular caulked portions (32b) protrude from both ends of the flange portion (32a), and these annular caulked portions are inserted into the openings (21a) (22a). A configuration may be adopted in which flaring is performed and the peripheral edge of the opening is caulked between the opening and the flange (32).

Further, in this embodiment, the open ends of the inlet side pipe (21) and the outlet side pipe (22) are the connection ends (23) and (24).
As in the conventional heat exchanger shown in FIG. 1, this open end is used as an intermediate connection part (210) (220), and the circuits on the open end side of the inlet side pipe (21) and the outlet side pipe (22) are connected thereto. You may make it connect.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a conventional example.

FIG. 2 is a plan view thereof.

FIG. 3 is an explanatory diagram of an embodiment of the present invention.

FIG. 4 is a plan view thereof.

FIG. 5 is an enlarged view of the main part.

FIG. 6 is a sectional view of a ring body (32).

FIG. 7 is a diagram showing the relationship between the fin (F) and the brazing material (R) during brazing work.

FIG. 8 is an explanatory view of another embodiment of the ring body (32).

[Explanation of symbols]

 (1) ・ ・ ・ can body (F) (F) ・ ・ fin (2) ・ ・ ・ water supply pipe (21) ・ ・ ・ inlet pipe (22) ・ ・ ・ outlet pipe (3) ・ ・ ・ bypass Circuit (21a) ・ ・ Opening (22a) ・ ・ Opening (31) ・ ・ ・ Communication port

Claims (4)

(57) [Claims] A large number of fins (F) (F) are juxtaposed in a can body (1), and a water supply pipe (2) is penetrated therethrough.
The inlet side pipe (21) and the outlet side pipe (22) are attached to the surface of the can body (1), and the inlet side pipe (21) and the outlet side pipe (22).
A heat exchanger for a water heater comprising a bypass circuit (3) between the upstream side of the inlet side pipe (21) and an outlet side pipe.
The downstream part of (22) is overlapped on the surface of the can body (1), and an opening (21a) and an opening (22a) are formed in the water supply pipe constituting wall of this overlapping part, and these openings are aligned with each other. A heat exchanger for a water heater, wherein the communication port (31) formed between the openings (21a) (22a) is fixed to the bypass circuit (3). 2. The openings (21a) and (22a) are caulked with a ring body (32) to form a communication port (31), and the inlet-side pipe (21) is formed.
And the surface of the outlet pipe (22) and the can body (1) and the opening (21a)
The heat exchanger for a water heater according to claim 1, wherein the peripheral portions of the (22a) are brazed to each other. 3. A plurality of fins (F) (F) are juxtaposed in a can body (1), and a water supply pipe (2) is penetrated therethrough.
The inlet side pipe (21) and the outlet side pipe (22) are attached to the surface of the can body (1), and the inlet side pipe (21) and the outlet side pipe (22).
In the method for manufacturing a heat exchanger for a water heater of a type in which a bypass circuit (3) is configured between the upstream side of the inlet side pipe (21) and the downstream side of the outlet side pipe (22), ), The opening (21a) and the opening (22
a) and caulking with a ring body (32) so that these openings coincide with each other, and then the inlet side pipe (21)
A brazing material is disposed at a joint between the outlet pipe (22) and the surface of the can body (1), and a brazing material is disposed at a joint at the periphery of the openings (21a) and (22a). A method for manufacturing a heat exchanger for a water heater, comprising a step of heating and brazing to a predetermined temperature in a state. 4. An opening (2) from an upstream open end of the inlet pipe (21).
1a) and opening from the downstream open end of the outlet pipe (22)
(22a) is set to a length that allows a caulking tool to be inserted from the open end, and the step of caulking the openings (21a) and (22a) to each other with a ring body (32) includes an inlet side pipe ( twenty one)
4. The method for manufacturing a heat exchanger for a water heater according to claim 3, wherein the step of caulking is performed by using the caulking tool inserted from the upstream open end and the downstream open end of the outlet pipe (22).