JP3317672B2 - Heat exchanger - 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 used for various types of air conditioners, such as condensers for car air conditioners and refrigerators.

[0002]

2. Description of the Related Art Generally, a heat exchanger used for a condenser for a car air conditioner and the like has a large number of heat exchange paths between a pair of headers arranged in parallel, both ends of which are connected to both headers. The core part is constructed by arranging the corrugated fins in parallel with each other, and the heat exchange medium flowing from the inlet of the header exchanges heat with the outside air in the process of flowing in a meandering manner through the core part by the partitions in both headers. And flow out from the outlet.

Heretofore, as the above-mentioned header, a cylindrical one made of aluminum material has been frequently used, and the connection of the heat exchange medium introduction pipe and the discharge pipe to the outlet of the header is provided on the peripheral surface of the header. The end of the reduced diameter is directly inserted into the connection hole and brazed, or connected via a connection flange fixed to the side or end of the header, or to the opening end of the header. Various connection means such as connection via a pipe joint such as a union joint are employed.

Among the above-mentioned connecting means, the means for inserting and brazing the end of the reduced-diameter tube body, particularly, does not require any intervening material at the joint, and is simple in structure and cost. It is advantageous. Conventionally, as shown in FIG. 5 (A), the end (11a) of a round pipe (11) forming an inlet pipe and an outlet pipe is reduced in diameter to a concentric circumferential circle. As shown in (1), the end (11a) is inserted into the connection hole (2) of the header (1) via a ring-shaped brazing material (not shown) and joined by torch brazing.

However, in the above-mentioned conventional method, since the header (12) is cylindrical and the opening edge of the connection hole (2) is formed in a three-dimensional shape, a portion along the header axial direction on both sides of the opening edge is formed. (21) is difficult to make close contact, and there is a problem that a gap is formed in the fitting portion and the brazing property is inferior, and the yield of the product is reduced due to poor sealing. In particular, when the header (1) is formed by bending a flat plate material in which the connection hole (2) is punched in advance into a cylindrical shape, the inner peripheral surface of the connection hole (2) expands outward during the bending. Therefore, the end portions of the inserted tubular body are less likely to be in close contact with each other, and the above-mentioned reduction in yield is remarkable.

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention inserts a reduced-diameter end of an introduction pipe or a discharge pipe made of a round pipe into a connection hole opened on the peripheral surface of a cylindrical header and brazes the same. In a heat exchanger having a configuration for connection, the closeness between the opening periphery of the connection hole and the end of the inserted pipe body is enhanced to provide good brazing properties, thereby ensuring sealing and improving product yield. It aims to provide a means to improve.

[0007]

In order to achieve the above object, a heat exchanger according to the present invention is provided by previously punching a connection hole.
A heat exchange medium is provided between a pair of parallelly arranged cylindrical headers formed by bending the formed flat plate into a cylindrical shape, and a heat exchange medium introduction pipe connected to the cylindrical header and At least one of the outlet pipes is formed of a round pipe, and the reduced-diameter end of the round pipe opens to the peripheral surface of the cylindrical header, and the inner peripheral surface expands outward with the bending of the flat plate material. In the heat exchanger, which is inserted into the connection hole formed on the surface and connected by brazing, the circumferential boundary between the reduced diameter portion and the non-reduced diameter portion of the round pipe is the connection hole of the cylindrical header. Has a shape corresponding to the three-dimensional shape of the peripheral edge of the opening, and has a tapered surface which is inclined from the non-reduced diameter portion to the reduced diameter end in the entire periphery thereof, and the end of the round pipe is connected to the connection hole of the header. When inserted, the circumferential border is connected It matches all around the periphery of the opening of, and it is assumed that formed by close contact with the tapered faces.

According to the above construction, when the reduced-diameter end of the round pipe forming the inlet pipe and the outlet pipe is inserted into the connection hole of the cylindrical header, the root shape of the end and the opening of the connection hole are formed. Since the peripheral shape matches the entire circumference and the tapered portion comes into surface contact, a gap is hardly formed in the fitting portion, and the sealing performance by brazing is improved. In addition, in the above-mentioned insertion, the direction of the round pipe and the insertion depth are automatically adjusted by fitting the root of the reduced-diameter end portion so that the uneven shape matches the periphery of the opening of the connection hole. Is determined. However, even if the header is formed by bending a flat plate material in which connection holes are punched in advance into a cylindrical shape, and the inner peripheral surface of the connection hole expands outward, the reduced diameter portion and the non-reduced portion can be used. The circumferential boundary with the diameter portion can be tapered so that the tapered surfaces are in close contact with each other.

[0009]

Next, an embodiment of a heat exchanger according to the present invention will be specifically described with reference to the drawings. FIG. 1 is a front view of the heat exchanger, FIG. 2 (A) is a partially cutaway front view showing an enlarged main part of the heat exchanger, and FIG. 1 (B) is a cross-sectional plan view of the main part.

This heat exchanger is used for a condenser for a car air conditioner or the like. As shown in FIG. 1, a pair of left and right cylindrical headers (1a) and (1b) are opposed to each other and are separated from each other. A large number of flat tubes (3) extending in the horizontal direction as heat exchange conduits are arranged in parallel at equal intervals in a state where both ends are connected to both headers (1a) (1b). Corrugated fins (4) are arranged between adjacent tubes (3) ...
0). (5) is a strip-shaped cover disposed on the upper and lower edges of the core (10).

Then, the left cylindrical header (1a)
Is divided by two partition plates (6a) and (6b) at an intermediate height and a lower portion, and a heat exchange medium (refrigerant) inlet pipe (7) is positioned above the upper partition plate (6a).
a) is connected, and an outlet pipe (7b) for the heat exchange medium is connected below the lower partition plate (6b). On the other hand, the right cylindrical header (1b) is internally partitioned by a partition plate (6c) located at an intermediate height between the two partition plates (6a) and (6b) in the left header (1a). Thereby, the gas of the heat exchange medium (refrigerant) flowing from the introduction pipe (7a) exchanges heat with the outside air in the meandering flow of the core portion (10) by the partition of the headers (1a) and (1b). It condenses and flows out as a gas-liquid mixed state from the outlet pipe (7b).

The headers (1a) and (1b) are both made of a flat aluminum plate bent into a cylindrical shape, and the inlet pipe (7a) and the outlet pipe (7b) of the left header (1a). Connection holes (2a) and (2b) are punched and formed in advance in the flat plate before bending at the connection portion. Thus, both connection holes (2a) and (2b) correspond to FIGS.
The inner peripheral surface (20) is formed as a tapered surface that expands outwardly as the flat plate material is bent into a cylindrical shape, as typically shown by the connection portion on the side of the introduction pipe (7a). I have.

In addition, an inlet pipe (7a) and an outlet pipe (7b)
Although the former is larger in diameter than the latter, both are made of aluminum round pipes (7), and as shown by the connection part on the introduction pipe (7a) side in FIGS. 2 (A) and 2 (B), In a state where the reduced diameter end portion (71) of the round pipe (7) is directly inserted into the connection hole (2a) of the header (1a), the inserted portion is brazed.

In this case, as shown in FIGS. 3 and 4,
Non-reduced diameter part (70) and reduced diameter end (71) of round pipe (7)
The boundary (72) in the circumferential direction with the three-dimensional shape of the peripheral edge of the opening in the connection hole (2a) of the header (1a),
End portions that are convexly curved toward the distal end at both side portions (72a) and (72a) and concavely curved at the upper and lower portions (72b) and (72b), and whose diameter is reduced from the non-diameter-reduced portion (70) over the entire circumference. It forms a tapered surface inclined to (71). Therefore, FIG.
As shown in (B), the connection hole (2) of the header (1a) is formed.
In the state where the end (71) of the round pipe (7) is inserted into a), the circumferential boundary (72) coincides with the opening periphery of the connection hole (2a) over the entire circumference, and the tapered surfaces are in close contact with each other. are doing.
Although not shown, the above-mentioned insertion state is the same on the outlet pipe (7b) side.

In the assembling and manufacturing of this heat exchanger, the inlet pipe (7a) and the outlet pipe (7b) and the header (1a) are, as shown in FIG. The rounded end (71) of the round pipe (7) is connected to the connection holes (2a) (2b) of the header (1a) with or without the interposition of a ring-shaped brazing material (8) bent along the line , And integrated by torch brazing, but since this fitting part is in close contact with no gap over the entire circumference,
Good brazing properties are obtained, and poor sealing of the fitting portion is unlikely to occur. Further, when the inlet pipe (7a) and the outlet pipe (7b) are inserted into the connection holes (2a) and (2b), the unevenness of the circumferential boundary (72) is formed on the periphery of the opening of the connection holes (2a) and (2b). The fitting and the setting of the direction of the pipe member (7) can be easily performed because the fitting may be performed. The connection and integration of the cylindrical headers (1a) and (1b) on both sides and the flat tubes (3) and the corrugated fins (4) are usually performed before the connection of the inlet pipe (7a) and the outlet pipe (7b). These are temporarily assembled and brazed together in a furnace.

Incidentally, the sealability of the connection portion was examined by an actual machine test for 1,000 heat exchangers to which the inlet pipe (7a) and the outlet pipe (7b) were attached by such a connection structure. Only two (0.2%) leaked liquid from the part. On the other hand, when the conventional connection structure as shown in FIG. 5 is adopted, the liquid leakage is generally about 7%. Therefore, it can be seen that in the manufacture of the heat exchanger according to the present invention, the product yield is greatly improved as compared with the related art.

In the above embodiment, both the inlet pipe (7a) and the outlet pipe (7b) for the heat exchange medium are directly connected to the cylindrical header (1a) on one side. Both pipes (7a) depending on the set number of exchange medium paths
Depending on the configuration in which (7b) is divided and connected to both side headers (1a) and (1b) and the specifications of the heat exchanger, both pipes (7a)
A configuration in which one of (7b) is connected to the header via a connection flange or a pipe joint may be adopted. The overall specifications of the heat exchanger such as the length and width of the headers (1a) and (1b) on both sides and the number of partitions, the number of heat exchange passages, and the attachment of a receiver tank and the like in the case of a subcooled system condenser are other than the examples. Can be variously set.

[0018]

According to the present invention, the connection hole is punched in advance.
At least one of the inlet pipe and the outlet pipe of the heat exchange medium connected to the cylindrical header formed by bending the formed flat plate into a cylindrical shape comprises a round pipe, and a reduced-diameter end of the round pipe. Is open on the peripheral surface of the cylindrical header,
On the tapered surface where the inner peripheral surface expands outward as the material is bent
In the heat exchanger which is inserted into the formed connection hole and connected by brazing, the circumferential boundary between the reduced diameter portion and the non-reduced diameter portion of the round pipe has a three-dimensional shape of an opening periphery of the connection hole. In the state where the end of the round pipe is inserted into the connection hole of the header, it has a shape corresponding to Since the circumferential boundary coincides with the periphery of the opening of the connection hole on the entire circumference, and the tapered surfaces are in close contact with each other, it is difficult to form a gap in the connection fitting portion between the introduction pipe and the discharge pipe and the cylindrical header, and brazing is performed. And the yield of products in assembling and manufacturing the heat exchanger is greatly improved as compared with the related art.

[Brief description of the drawings]

FIG. 1 is a front view of a heat exchanger according to one embodiment of the present invention.

2A and 2B show a connection portion of a heat exchange medium introduction pipe in the heat exchanger, wherein FIG. 2A is a partially cutaway front view, and FIG. 2B is a cross-sectional plan view.

FIG. 3 is an exploded perspective view showing an operation of connecting an introduction pipe to a cylindrical header of the heat exchanger.

4A and 4B show a connection operation of the introduction pipe, wherein FIG. 4A is a cross-sectional plan view and FIG. 4B is a front view.

5A and 5B show a connection method of a heat exchange medium introduction pipe or a discharge pipe in a conventional heat exchanger. FIG. 5A is a perspective view of a round pipe whose end is reduced in diameter, and FIG. It is a front view of the connection part of a cylindrical header.

[Explanation of symbols]

 1a, 1b ... cylindrical header 10 ... core 2a, 2b ... connection hole 3 ... flat tube 4 ... corrugated fin 7 ... round pipe 7a ... introduction of heat exchange medium Pipe 7b ... Outlet pipe for heat exchange medium 70 ... Non-reduced diameter section 71 ... Reduced diameter section 72 ... Circumferential boundary

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F28F 9/00-9/26

Claims (1)

(57) [Claims] 1. A flat plate material in which connection holes are previously punched and formed.
A core portion through which a heat exchange medium flows is provided between a pair of parallelly arranged cylindrical headers formed by bending into a cylindrical shape, and at least one of an inlet pipe and an outlet pipe of the heat exchange medium connected to the cylindrical header. Consists of a round pipe, the reduced-diameter end of the round pipe opens on the peripheral surface of the cylindrical header ,
In a heat exchanger, which is inserted and fitted into a connection hole formed in a tapered surface whose inner peripheral surface expands outward along with bending of a flat plate material and connected by brazing, The circumferential boundary with the reduced diameter portion has a shape corresponding to the three-dimensional shape of the opening periphery of the connection hole of the cylindrical header, and is inclined from the non-reduced portion to the reduced diameter end portion over the entire circumference. It is composed of a tapered surface,
In the state where the end of the round pipe is inserted into the connection hole of the header, its circumferential boundary coincides with the entire periphery of the opening of the connection hole, and the tapered surfaces are in close contact with each other. vessel.