JP3823904B2 - Heat exchanger - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat exchanger used in a vehicle air conditioner and the like, in which a liquid flows.
[0002]
[Prior art]
In an automobile air conditioner, a heat exchanger using waste heat of engine cooling water is used as a heater core. The heater core has a structure in which an upper tank and a lower tank are connected by a large number of tubes arranged in parallel, and radiating fins are brazed between the tubes. In the heater core, a partition plate is provided in the upper tank so as to partition the upstream side, which is the inlet side of the hot water, and the downstream side, which is in communication with the outlet, thereby improving the heating effect. The liquid (warm water) flows from the upper tank to the lower tank through the upstream tube group of the partition plate, then flows from the lower tank to the upper tank through the downstream tube group of the partition plate, and flows out from the outlet.
[0003]
[Problems to be solved by the invention]
In a heat exchanger in which the inside of the upper tank is partitioned by a partition plate and the liquid flows in a U-turn shape or an N-turn shape between the upper tank and the lower tank, small bubbles contained in the liquid are separated from the partition plate in the upper tank. Stays upstream to form an air reservoir. Each time the air reservoir is removed, water flow noise is generated in the heat exchanger, causing a complaint from the user.
[0004]
In order to prevent this noise, the partition plate has a hole for venting air.Sound is generated when the air pool passes through this hole, and the liquid before heat exchange is short-circuited from this hole to the leakage outlet. Therefore, there is a problem that the heat exchange efficiency is lowered.
An object of the present invention is to provide a heat exchanger having an air vent hole that can effectively prevent the generation of sound when the air reservoir staying in the upper tank escapes and can minimize the short circuit of the liquid before heat exchange. Is in the provision of.
[0005]
[Means for Solving the Problems]
According to the first aspect of the present invention, in the heat exchanger having a partition plate for partitioning the inside of the upper tank into an upstream side and a downstream side, an air vent hole having a protruding edge protruding upstream is provided at an upper portion of the partition plate. ing. By the action of the air vent hole with a protruding edge, the air accumulated on the upstream side of the partition plate can be continuously and selectively extracted in an appropriate amount to prevent liquid from leaking through the air vent hole while preventing the generation of water flow noise. Can be suppressed. From the viewpoint of quick and smooth air bleeding, it is desirable that the air vent hole is located at the highest position along the ceiling wall of the upstream tank and with the heat exchanger installed.
[0006]
In the invention described in claim 2, the protruding edge is formed by burring. Therefore, a protruding edge that protrudes smoothly upstream can be formed at a low cost. The protruding edge formed by burring is smoothly curved in shape, and the liquid protrudes and flows smoothly along the outer surface of the edge. As a result, it is possible to prevent the flow from being disturbed and the liquid from entering the air vent hole. Further, since the air vent hole has a small entrance at the tip, the passage resistance to the liquid is large, and there is an advantage that only air selectively passes.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an outlet 21 portion of a heat exchanger (shown in FIG. 2) according to one embodiment of the present invention. The heat exchanger 1 is installed in an automobile air conditioner and is used as a heater core that uses engine coolant as a heat source. The heat exchanger 1 includes a horizontally long upper tank 2 and a lower tank 3. A liquid (warm water) outlet 21 is provided on the upper surface of the central portion of the upper tank 2, and hot water inlets 31, 31 are provided on the left and right ends of the lower tank 3.
[0008]
The upper tank 2 and the lower tank 3 are arranged parallel to each other in the vertical direction, and have a structure in which bowl-shaped tank bodies 23 and 33 are abutted and joined to the upper and lower surfaces of the sheet metals 22 and 32, respectively. The upper tank 2 and the lower tank 3 are communicated with a concentration pipe 11 disposed in the central portion and a number of flat tubes 4 including left and right tube groups 4A and 4A disposed in parallel to the left and right of the concentration pipe 11. ing.
[0009]
Side plates 12 and 12 that connect the left and right ends of the sheet metals 22 and 32 are installed outside the numerous tubes 4. The concentration tube 11 and the flat tube 4 are connected to the upper and lower ends through the sheet metals 22 and 32, respectively. Corrugated fins 13 are brazed to the gaps between the concentration tube 11, each flat tube 4 and the side plate 12.
[0010]
In the upper tank 2, partition plates 5, 5 are installed near the center, and are connected to the upstream side 2 A, 2 A communicating with the upper ends of the left and right tube groups 4 A, 4 A, the upper end of the concentration pipe 11, and the hot water outlet 21. The downstream side 2B that communicates is partitioned. An air vent hole 6 having a protruding edge 61 protruding toward the left and right tube groups 4A and 4A (upstream side) is provided in the upper part of the partition plates 5 and 5.
[0011]
In the lower tank 3, partition plates 7 and 7 are installed on the outer side, and are divided into upstream (outside) 3A, 3A and downstream (inside) 3B. The upstream side (outer side) 3A, 3A communicates with the lower ends of the outer tube groups 4B, 4B among the many flat tubes 4, and the downstream side (inner side) 3B is the lower end of the concentration tube 11 and the inner tube groups 4C, 4C. Communicating with
[0012]
The air vent hole 6 is formed by pressing the upper edge of the partition plate 5 and has a slit shape along the ceiling inner wall 24 of the upper tank 2. The protruding edge 61 is smoothly curved toward the distal end side (the left and right sides in the figure), and has a half-shell shape with a thin front end. The air vent hole 6 and the protruding edge 61 may be formed by press molding or other processing methods, but formation by burring is most advantageous from the viewpoint of reducing processing costs and water flow noise.
[0013]
The engine coolant flows into the upstream (outside) 3A, 3A of the lower tank 3 from the inlets 31, 31 and flows to the upstream 2A, 2A of the upper tank 2 through the outer tube groups 4B, 4B. Subsequently, it flows to the downstream side (inside) 3B of the lower tank 3 through the inner tube groups 4C and 4C, enters the downstream side 2B (between the partition plates 5 and 5) of the upper tank 2 through the concentration pipe 11, and flows out. It flows in an N-turn shape that flows out from 21.
[0014]
When the air bubbles a mixed in the engine cooling water flow N-turns in the heat exchanger 1, the air bubbles A accumulate in the ceilings of the upstream sides 2A and 2A of the upper tank 2 to form an air reservoir A. The air in the air reservoir A passes through the air vent hole 6 to the downstream side 2B (between the partition plates 5 and 5) of the upper tank 2 and flows out from the outlet 21. At this time, since air gradually escapes by an appropriate amount by the action of the flat protruding edge 61, the generation of sound when air escapes is prevented.
[0015]
The air vent hole 6 also serves as a so-called short-circuit channel in which hot water leaks from the upstream side 2A, 2A of the upper tank 2 to the downstream side 2B and flows out from the outlet 21. In the present invention, since the protruding edge 61 is provided by burring, the area of the air vent hole 6 gradually decreases in a quadratic curve toward the tip side (upstream side). For this reason, since the inlet of the air vent hole 6 is narrow, the passage of air is performed quickly, but the passage resistance to the liquid is large, and the amount of bypass of hot water is small.
[0016]
FIG. 4 shows an air vent hole 8 according to another embodiment. In this embodiment, the air vent hole 8 has a rectangular slit shape along the ceiling inner wall 24 of the upper tank 2, and the edge 81 is formed along the bottom side 82 of the air vent hole 8. The air vent hole 8 can also evacuate air from the gap 83 on the side of the edge 81, and has an effect of suppressing the growth of the air reservoir.
[0017]
FIG. 5 shows the heat exchanger 1 installed as a heater core in which engine cooling water circulates in an air conditioning duct 10 of an automotive air conditioner. The air vent hole 6 (8) is set at the uppermost position where air is accumulated in a state where the heat exchanger 1 is installed, and is formed close to the ceiling inner wall 24. As a result, before the bubbles a concentrate and grow into a large air reservoir A, the air can be removed in small amounts.
[0018]
[Modification]
The shape of the air vent hole may be a large group of small holes formed by burring. The heat exchanger may have a partition plate in the upper tank, an inlet in one of the partition plates, and an outlet in the other, and the liquid may flow in a U-turn shape.
[Brief description of the drawings]
FIG. 1 is an enlarged view of an outlet portion of a heat exchanger according to the present invention.
FIG. 2 is a front view showing an outline of a heat exchanger.
FIG. 3 is a side sectional view of the upper tank.
FIG. 4 is a side sectional view of an upper tank according to another embodiment.
FIG. 5 is an installation state diagram of a heater core.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Heat exchanger 2 Upper tank 3 Lower tank 4 Flat tube 5 Partition plate 6 Air vent hole 61 Projecting edge 8 Air vent hole (other embodiment)
A Air pool

Claims (2)

In a heat exchanger comprising an upper tank, a lower tank, a large number of tubes communicating with the upper tank and the lower tank, and a partition plate that partitions the upper tank into an upstream side and a downstream side,
A heat exchanger, wherein an air vent hole having a protruding edge projecting upstream is provided in an upper portion of the partition plate. 2. The heat exchanger according to claim 1, wherein the protruding edge is formed by burring.

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