JPH1071463A - Manufacture of flat heat exchanger tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To firmly braze an upper and lower structural members with each other. SOLUTION: The flat heat exchanger tube is manufactured by brazing a planar upper and lower structural members 20, 10. The planar lower structural member 10 is constituted of a lower wall forming part 13; left/right side wall forming parts integrally formed in a raised shape on the lower wall forming part 13; and reinforcing wall forming part 11, which is integrally formed in a raised shape on the lower wall forming part 13, and which is formed with plural notches 12 on the upper edge in the longitudinal direction at spaces apart. The planar upper structural member 20 is constituted of an upper wall forming part 21 which consists of a brazing sheet with a filler metal layer on the lower face and which extends over both side wall forming parts of the lower structural member 10. At least one projected line 23 is preliminarily formed in the longitudinal direction on the part corresponding to the reinforcing wall forming part 11 in the lower face of the upper wall forming part 21 of the upper structural member 20; the upper and lower structural members 20, 10 are first tack-welded with a force applied from the top and the bottom, and then brazed with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat heat exchange tube used for a heat exchanger such as a condenser for a car air conditioner, an evaporator for a car air conditioner, a condenser for a room air conditioner, an oil cooler for an automobile, and an oil cooler for an industrial machine. It relates to a method of manufacturing.

In this specification, the upper, lower, left and right in FIGS. 1 and 5 are respectively referred to as upper, lower, left and right. However, in the description related to FIG. 13, the upper and lower sides and the left and right sides of FIG.

[0003]

2. Description of the Related Art Recently, as a capacitor for a car air conditioner, for example, as shown in FIG. ) And both ends are both headers (31) (3
The two parallel refrigerant flow pipes (33) are disposed in the ventilation gap between the parallel flat refrigerant flow pipes (33) (heat exchange pipes) connected to 2) and the adjacent refrigerant flow pipes (33). Corrugated fins (34), an inlet pipe (35) connected to the upper end of the peripheral wall of the left header (31), and an outlet pipe (35) connected to the lower end of the peripheral wall of the right header (32). 36), a left partition plate (37) provided inside a position above the middle of the left header (31), and a right header (32)
A right partition plate (38) provided at a position lower than the middle of the number of refrigerant flow pipes (33) between the inlet pipe (35) and the left partition plate (37), and a left partition plate. (37) and the number of refrigerant flow pipes (33) between the right partition plate (38) and the number of refrigerant flow pipes (33) between the right partition plate (38) and the outlet pipe (36) are sequentially reduced from the top. By the way, the gas phase refrigerant flowing from the inlet pipe (35) flows in the liquid phase from the outlet pipe (36) and flows out of the outlet pipe (36) in a meandering manner for each passage group. A so-called multi-flow type capacitor (see Japanese Patent Publication No. 3-45300) which is made to flow can realize high performance, low pressure loss and ultra compactness in place of a conventional serpentine type capacitor. It has been widely used.

[0004] The flat refrigerant flow pipe used in the condenser is required to have a pressure resistance because a high-pressure gas refrigerant is introduced into the inside thereof. In order to meet this demand and increase the heat exchange efficiency, the refrigerant flow pipe is made of an aluminum hollow extruded shape having flat upper and lower walls and a reinforcing wall that extends over the upper and lower walls and extends in the length direction. Had been. By the way, in view of the improvement of the heat exchange efficiency and the downsizing of the condenser, it is desirable that the flat refrigerant flow pipe is thin and the height is as low as possible. However, in the case of extruded shapes, there is a limit in reducing the pipe height and reducing the wall thickness due to the restriction on the extrusion technique.

Therefore, in order to solve this problem, the present applicant firstly described the upper and lower walls, the left and right side walls extending over the left and right side edges of the upper and lower walls, the upper and lower walls, and extending in the longitudinal direction and extending each other. A plurality of reinforcing walls provided at intervals in the longitudinal direction, having a plurality of parallel fluid passages therein, and a plurality of communication holes for allowing the parallel fluid passages to pass through the reinforcing walls at intervals in the longitudinal direction. A flat heat exchange tube formed by rolling a plate material, and a lower wall forming portion, left and right side wall forming portions integrally formed in the lower wall forming portion in an upwardly protruding shape, and a lower wall. A lower plate-shaped component member consisting of a reinforcing wall forming portion integrally formed in an upper protruding shape in a forming portion and having a plurality of notches formed at an upper edge thereof at intervals in a length direction, and a brazing material layer on a lower surface. Consisting of a brazing sheet having Proposed a flat heat exchange tubes produced by brazing the plate on component having a top wall forming portion that spans both side walls forming part of the timber (JP-A-6-28
1373).

However, since the lower component is formed by rolling, as shown in FIG.
The height positions of the upper edges of the portions (43A), (43B), and (43C) between the adjacent notches (42) in the reinforcing wall forming portion (41) of (0) may not be the same but may be different. And as a result all above parts
Only the upper edge of a part (43A) of (43A), (43B) and (43C) contacts the upper wall forming part (51) of the upper component (50), and the other part (4
In 3B) and (43C), there is a slight gap between the upper edge and the upper wall forming portion (51). Therefore, at the time of brazing, of all the parts (43A), (43B), and (43C), the parts (43B) and (43C) in which a gap exists between the upper edge and the upper wall forming part (51) are upper constituent members. (50) is not brazed to the upper wall forming portion (51), and is required due to insufficient brazing strength between the upper component member (50) and the reinforcing wall forming portion (41) of the lower component member (40). There is a problem that the pressure resistance cannot be satisfied.

In order to solve such a problem, it is conceivable to increase the thickness of the brazing material layer on the lower surface of the upper component. However, in this case, the brazing material drips during brazing, and as a result, the There is a possibility that the cross-sectional area is reduced and the passage resistance is increased, and in severe cases, the fluid passage is closed. Moreover, the notch, that is, the communication hole formed in the reinforcing wall may be closed.

An object of the present invention is to provide a method for manufacturing a flat heat exchange tube which solves the above problems.

[0009]

SUMMARY OF THE INVENTION A method of manufacturing a flat heat exchange tube according to the present invention is characterized in that it extends over the upper and lower walls, the left and right side walls over the left and right side edges of the upper and lower walls, the upper and lower walls, and extends in the longitudinal direction. A plurality of reinforcing walls provided at intervals from each other, and having a plurality of parallel fluid passages therein, and a plurality of communication holes through which the parallel fluid passages pass through the reinforcing walls are spaced apart in the length direction. The flat heat exchange tube that is opened is formed integrally with the lower wall forming portion, the left and right side wall forming portions integrally formed in the lower wall forming portion in an upwardly protruding manner, and the upper wall in the lower wall forming portion, and A plate-like lower component having a reinforcing wall forming portion having a plurality of notches formed at intervals in a length direction at an upper edge, and a brazing sheet having a brazing material layer on a lower surface, and both sides of the lower component Upper wall forming part straddling the wall forming part In manufacturing by brazing the plate-shaped upper component member having, at least one ridge extending in the length direction is formed on a portion corresponding to each reinforcing wall formation portion on the lower surface of the upper wall formation portion of the upper component member. In addition, after temporarily fixing the upper and lower components in a state in which a force is applied from above and below, the components are brazed.

According to the method of manufacturing a flat heat exchange tube of the present invention, when the upper and lower structural members are temporarily fixed, the ridges come into contact with the portions between the adjacent notches in the reinforcing wall forming portion. In other words, the height positions of the upper edges of all of the above-described portions are variously different, and thus, even if there is a portion where a gap exists between the upper component member and the lower surface of the upper wall forming portion, the interval of such a gap is small. If the protrusion height is equal to or smaller than the protrusion height, this portion comes into contact with the protrusion on the lower surface of the upper wall forming portion of the upper component and is brazed to the protrusion. Therefore, the brazing strength between the upper and lower components increases as compared with the conventional case.

In the above method for manufacturing a flat heat exchange tube,
Both the upper end corners of the reinforcing wall forming portion and the tips of the protruding ridges are formed in an arc shape in cross section, and a pair of the protruding ridges are present at the portions corresponding to the respective reinforcing wall forming portions, and the two components are temporarily fixed. It is preferable that each ridge is positioned so that the oblique horizontal portion of the tip of each ridge hits one corner of the reinforcing wall forming portion, thereby applying a force to both components from above and below. At the time of temporary fixing in the state, at least one of the phenomenon that the upper end of the reinforcing wall forming portion pushes out between a pair of ridges and the deformation of the upper end both corners occurs, so that the reinforcing wall forming portion and the ridges Has a large contact area and good brazing.

In the above method for manufacturing a flat heat exchange tube,
Preferably, a plurality of ridges are formed at intervals in the width direction of the lower surface of the upper wall forming portion of the upper component. In this case, the ridge that is not located at the position corresponding to the reinforcing wall forming portion and is not subjected to brazing with the reinforcing wall forming portion acts to increase the heat transfer area of the manufactured flat strip heat exchange tube, Improve heat exchange efficiency.

In the above method for manufacturing a flat heat exchange tube, both the left and right side edges of the upper wall forming portion of the upper component have a drooping length greater than the height of both side wall forming portions of the lower component and both sides. A hanging wall overlapping the outside of the wall forming portion is integrally formed, and a lower end portion of the hanging wall is bent inward in the left-right direction to be engaged with left and right side edges of the lower surface of the lower wall forming portion of the lower component. Therefore, it is preferable to temporarily fix the upper and lower components.
In this case, a jig or the like for temporarily fixing the upper and lower components is not required. In the manufactured flat heat exchange tube,
Since the left and right side walls have a double structure, the pressure resistance of this portion is improved.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described.
This will be described with reference to the drawings. In the following description, the term “aluminum” includes an aluminum alloy in addition to pure aluminum.

FIGS. 1 and 2 show a flat heat exchange tube manufactured in this embodiment. In FIGS. 1 and 2, the flat heat exchange tube (A) is composed of flat upper and lower walls (1) and (2) and upper and lower walls.
(1) Left and right side walls of a double structure that straddles the left and right side edges of (2)
(3) A plurality of reinforcing walls extending between the left and right side walls (3) and (4), extending over the upper and lower walls (1) and (2), extending in the length direction, and spaced from each other by a predetermined distance. (5), and has a parallel fluid passage (6) inside.The lower wall (2), the left and right side walls (3) and (4), and the aluminum lower wall constituting the reinforcing wall (5) are provided. Component (10), top wall (1) and left and right side walls (3)
It is formed by a plate-shaped aluminum upper component member (20) constituting (4).

On the inner surface of the upper wall (1), a ridge (7) extending in the length direction is formed integrally with the lower wall so as to increase the heat transfer area. Lower wall (2) Adjacent reinforced wall on inner surface
(5) A plurality of projections (8) are integrally formed in the portion between each other so as to increase the heat transfer area at an interval in the longitudinal direction so as to protrude upward. The reinforcing wall (5) has a reinforcing wall forming part (11) formed integrally with the lower wall (2).
It is formed by being joined to the inner surface. The pitch of the reinforcing wall (5) in the pipe width direction is preferably 4 mm or less, and the height of the reinforcing wall (5) is preferably 2 mm or less. The reinforcing wall (5) is provided with a plurality of communication holes (9) through which the parallel fluid passages (6) pass.
The communication holes (9) are arranged in a zigzag pattern when viewed from above. When the communication holes (9) are provided, the fluid flowing through the parallel fluid passages (6) respectively flows through the communication holes (9) in the width direction of the flat heat exchange tube (A), and all the fluids flow. The fluid is mixed throughout the passages (6), so that there is no temperature difference in the fluid between the fluid passages (6). Therefore, the heat exchange efficiency is improved. The opening ratio, which is the proportion occupied by all the communication holes (9) in each reinforcing wall (5), is 10 to 40%, particularly 10 to 30%.
And preferably about 20%. In this case, the effect of improving the heat exchange efficiency by forming the communication hole (9) becomes remarkable. Communication hole
In (9), notches (12) formed at predetermined intervals on the upper edge of the reinforcing wall forming portion (11) are formed by closing the opening portion by the upper wall (1). is there. In this case, since the communication holes (9) formed in the plurality of reinforcing walls (5) are arranged in a staggered manner when viewed from a plane, both the component members (10) are arranged in the width direction of the flat heat exchange tube (A). (20) Since there is a joint between the two, sufficient joint strength is ensured.

The flat heat exchange tube (A) is manufactured as follows. First, a plate-shaped aluminum lower component (10) and a plate-shaped aluminum upper component (20) as shown in FIGS. 3 and 4 are formed by rolling.

The lower component (10) is a flat lower wall forming part (13).
And both side wall forming portions (14) integrally formed in a rising shape on both side edges of the lower wall forming portion (13), and a rising shape between both side wall forming portions (14) of the lower wall forming portion (13). And a plurality of reinforcing wall forming portions (11) integrally formed at predetermined intervals from each other and extending in the length direction, and the upper edge of the reinforcing wall forming portion (11) has a predetermined interval in the length direction. Here, trapezoidal notches (12) are formed so as to be staggered when viewed from a plane. The lower wall forming portion (13) of the lower component member (10), on the left and right side edges on the lower surface, an inclined surface (15) inclined upward outward in the left-right direction
Are formed. The height of the side wall forming portions (14) of the lower component (10) is equal to the height of the reinforcing wall forming portion (13).
Further, a projection (8) is integrally formed on the upper surface of the lower wall forming portion (13). The lower constituent member (10) is made of an aluminum brazing sheet having a brazing material layer (not shown) on the outer surface, that is, the lower surface of the lower wall forming portion (13) and the outer surface of both side wall forming portions (14).

The upper component (20) comprises a flat upper wall forming part (21).
And both side wall forming portions (22) (hanging walls) which are integrally formed in a hanging manner on both side edges of the upper wall forming portion (21) and overlap the outer sides of the both side wall forming portions (14) of the lower component (10). And Upper component (2
The width of the upper wall forming portion (21) is slightly larger than the width of the lower component (10), so that the upper wall forming portion (21) can cover the lower component (10). On the lower surface of the upper wall forming portion (21) of the upper component member (20), a plurality of ridges (23) extending in the length direction are spaced in the left-right direction and extend downward over the entire width except for predetermined width portions at both left and right ends. They are integrally formed in a raised shape. Therefore, the upper wall forming part (2
On the lower surface of (1), at least one ridge (23) exists at a portion corresponding to each reinforcing wall forming portion (11) of the lower component (10). The protrusion height of the ridges (23) is preferably about 10 to 200 μm. This is because the height position of the upper edge of the portion (16) between the adjacent notches (12) in the reinforcing wall forming portion (11) is variously different, so that the upper component forming portion (20) has the upper wall forming portion. (21) When the size of the gap existing between the lower surface and the lower surface is not smaller than 10 μm, and is smaller than 10 μm, the lower structure is also used for temporary fixing of both constituent members (10) and (20) described later. The upper end of the reinforcing wall forming portion (11) of the member (10) may not contact the ridge (23), and if it is higher than 200 μm, it is impossible to temporarily fix both the component members (10) and (20). This is because there is a fear. The hanging length of both side wall forming portions (22) of the upper component (20) is the lower component (10).
Is slightly larger than the height of both side wall forming portions (14). The upper component member (20) has two surfaces, that is, an upper wall forming portion (21).
And an aluminum brazing sheet having a brazing material layer (24) on both upper and lower surfaces and on both inner and outer surfaces of both side wall forming portions (22). Since the ridges (23) are formed simultaneously with the rolling of the upper component (20), as shown in FIG. 8, the thickness of the brazing material layer (24) at the ridges (23) is Thicker than the part.

Next, after the upper and lower structural members (20) and (10) are subjected to a degreasing treatment, a brazing flux is applied thereto.

Next, as shown in FIGS. 4 and 5, after the upper component (20) is fitted over the lower component (10), the lower component in both side wall forming portions (22) of the upper component (20) is removed. The portions of the component (10) projecting below the side wall forming portions (14) are bent inward to make close contact with the inclined surface (15) of the lower component (10), and both components (20) (10) ) Is temporarily fixed with force applied from above and below. At this time, as shown in FIGS.
Due to the different height positions of the upper edge of the portion (16) between adjacent notches (12) in (11), the upper component (20) and the upper wall forming portion (21) between the lower surface Even if there is a gap in the upper edge of each part (16), the upper wall forming part (21)
In close contact with If the size of the gap is smaller than the protruding height of the ridge (23), the ridge (23) is deformed. Also,
The upper wall forming part (21) is also slightly deformed.

Then, the two members (20) and (10) temporarily fixed are heated to the brazing temperature. Then, the lower component (10)
The upper wall forming portion (14) of which the upper end is the upper component member (20)
(21) The lower surface is brazed to the left and right ends, and the upper ends of both side wall forming portions (14) of the lower component (10) are brazed to the ridges (23). The thickness of the brazing material layer (24) at the protruding ridge (23) is thicker than at the other parts, so that when brazing, the molten brazing material is easily drawn to this part, forming a reinforcing wall. The gap between the upper surface of the portion (11) and the two ridges (23) is also closed. Further, both side wall forming portions (22) of the upper and lower constituent members (20) (10)
(14) The parts are brazed and the bent part at the lower end of the side wall forming part (22) of the upper component (20) is
It is brazed to the inclined surface (15) of (0) by a lap joint. Thus,
A flat heat exchange tube (A) is manufactured.

In the above-described embodiment, the ridge is formed over substantially the entire width of the lower surface of the upper wall forming portion. However, the present invention is not limited to this, and the ridge may be formed only at a portion corresponding to the reinforcing wall forming portion. . In particular, as shown in FIG. 9 and FIG. 11, both the upper end corners (28) of the reinforcing wall forming portion (27) and the tips of the ridges (29) are formed in a circular arc cross section, A pair of ridges (29) are present at the corresponding portions of the respective reinforcing wall forming portions, and at the time of temporarily fixing both the constituent members (10) and (20), the obliquely horizontal portions of the tips of the ridges (29) are Each ridge (29) is preferably positioned so as to hit one corner of the reinforcing wall forming portion. Since the interval (L2) between the pair of ridges (29) in FIG. 11 is slightly larger than the interval (L1) between the pair of ridges (29) in FIG. 9, the two component members (10) and (20) are assembled. In the combined state, the distance (l2) between the upper edge of the reinforcing wall forming portion (27) and the upper wall forming portion (21) in the former is determined by the upper edge of the reinforcing wall forming portion (27) and the upper wall forming portion in the latter. (21) interval (l
1) smaller than. When the two members (10) and (20) are temporarily fixed in a state where a force is applied from above and below, the distance (l1)
(L2) is shortened, the ridge (29) and the reinforcing wall forming part (27)
Both corners (28) of the upper part are deformed, but both sides (l1)
Since (l2) is different, the above-mentioned deformation mode is different, and the convex ridge (29) in FIG. 9 and both upper corners (28) of the reinforcing wall forming portion (27) are deformed convex ridges (29A) as shown in FIG. 11 and both upper corners (28A) of the deformed reinforcing wall forming portion (27), and both upper corners (28) of the ridge (29) and the reinforcing wall forming portion (27) in FIG. Article (29B) and deformation reinforcing wall formation (27)
(28B), a pair of deformed ridges (29B) and both corners (28B)
The contact area of the deformed ridge (29A) of FIG.
(28A) larger than the contact area.

[0024]

According to the method of manufacturing a flat heat exchange tube of the present invention, as described above, the brazing of the upper component and the lower component becomes strong, and sufficient pressure resistance can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a flat heat exchange tube manufactured by the method of the present invention.

FIG. 2 is a partially enlarged view of FIG.

FIG. 3 is a partial perspective view showing a method of combining an upper constituent member and a lower constituent member.

FIG. 4 is a cross-sectional view showing a state where an upper constituent member and a lower constituent member are combined.

FIG. 5 is a cross-sectional view showing a state where an upper component member and a lower component member are temporarily fixed.

FIG. 6 is a partially enlarged view of FIG. 5;

FIG. 7 is a sectional view taken along the line VII-VII in FIG. 6;

FIG. 8 is a partially enlarged view of FIG. 6;

FIG. 9 shows an example in which a pair of protrusions of an upper wall forming portion of an upper component member are present in a specific arrangement at a portion corresponding to a reinforcing wall forming portion, and a lower component member and an upper component member are combined. FIG. 4 is a partially enlarged cross-sectional view in a state in which it is folded.

FIG. 10 is an enlarged sectional view of the combination shown in FIG. 9 after being temporarily fixed.

FIG. 11 shows another example in which a brazing strength increasing ridge of the upper wall forming portion of the upper component member is present in a pair at a portion corresponding to the reinforcing wall forming portion in a specific arrangement. It is a partial expanded sectional view in the state where it combined with a constituent member.

FIG. 12 is an enlarged cross-sectional view of the combination of FIG. 11 after being temporarily fixed.

FIG. 13 is a front view of a condenser using a flat refrigerant flow pipe (heat exchange pipe).

FIG. 14 is a diagram corresponding to FIG. 7, showing a state in which both upper and lower constituent members are temporarily fixed by a conventional method.

[Explanation of symbols]

 (1) Upper wall (2) Lower wall (3) Left side wall (4) Right side wall (5) Reinforcement wall (6) Fluid passage (9) Communication hole (10) Lower component (11) (27) Reinforcement wall formation Part (12) Notch (13) Lower wall forming part (14) Side wall forming part (20) Upper component (21) Upper wall forming part (23) (29) Convex strip (24) Brazing filler metal layer (28) Upper corners of reinforcement wall forming section (A) Flat heat exchange tube

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yasuhiro Nori 6,224 Kaiyamacho, Sakai City Showa Aluminum Co., Ltd.

Claims (4)

[Claims] An upper and lower wall, a pair of left and right side walls extending over the left and right side edges of the upper and lower walls, and a plurality of reinforcing walls extending over the upper and lower walls and extending in a length direction and provided at intervals from each other; A flat heat exchange tube having a plurality of communication holes having parallel fluid passages therein and having a plurality of communication holes for allowing the parallel fluid passages to pass through the reinforcing wall at intervals in the length direction is formed by a lower wall forming portion and a lower wall. The left and right side wall forming portions integrally formed in an upper protruding shape in the wall forming portion, and a plurality of notches formed integrally in the upper protruding shape in the lower wall forming portion and spaced apart in the longitudinal direction at the upper edge. A plate-like lower component comprising a reinforcing wall forming portion, and a plate-like upper component comprising a brazing sheet having a brazing material layer on the lower surface and having an upper wall forming portion spanning both side wall forming portions of the lower component. To manufacture by brazing In addition, at least one ridge extending in the length direction is formed in a portion corresponding to each reinforcing wall forming portion on the lower surface of the upper wall forming portion of the upper component, and a force is applied to both the upper and lower components from above and below. A method for manufacturing a flat heat exchange tube, comprising temporarily brazing both constituent members after temporarily fixing in a state. 2. The method for manufacturing a flat heat exchange tube according to claim 1, wherein a plurality of ridges are formed at intervals in a width direction of a lower surface of an upper wall forming portion of the upper component. 3. Both the upper end corners of the reinforcing wall forming portion and the tip of the ridge are formed in an arc shape in cross section, and a pair of ridges are present in each portion corresponding to the reinforcing wall forming portion. 2. The flat shape according to claim 1, wherein, when temporarily fixing, each of the ridges is positioned such that an oblique horizontal portion of a tip end of each ridge hits one corner of the reinforcing wall forming portion. Method of manufacturing heat exchange tubes. 4. A hanging wall which has a drooping length greater than the height of the side wall forming portions of the lower component member and overlaps outside the side wall forming portions is integrated with the left and right side edges of the upper wall forming portion of the upper component member. The upper and lower components are temporarily fixed by bending the lower end of the hanging wall inward in the left-right direction and engaging the left and right side edges of the lower wall forming portion lower surface of the lower component. The method for manufacturing a flat heat exchange tube according to claim 1, 2, or 3.