Heat Exchanger

The present invention relates to a heat exchanger.

JP2013-185723A discloses a heat exchanger in which core portions having tank portions are provided so as to be overlapped. A distribution portion communication portion is connected to the tank portion of one of the core portions, and the distribution portion communication portion is connected to an intermediate tank portion. A collection portion communication portion is connected to the intermediate tank portion, and the collection portion communication portion is connected to the tank portion of the other of core portions.

However, in this heat exchanger, the tank portion of the one of the core portions and the tank portion of the other of the core portions are connected via the distribution portion communication portion, the intermediate tank portion, and the collection portion communication portion. Therefore, the structure thereof is complex.

An object of the present invention is to provide a heat exchanger capable of simplifying a structure for allowing a heat transfer medium to flow therethrough.

According to an aspect of the present invention, a heat exchanger configured to perform heat exchange between air and a heat transfer medium undergoing a phase change between a liquid phase and a gaseous phase, the heat exchanger includes: core portions provided such that a plurality of core portions are overlapped in an air-flow direction, the core portions each having header tanks provided as a pair facing with each other and a plurality of tubes configured to connect the header tanks to each other and to perform the heat exchange between the heat transfer medium flowing inside the tubes and the air flowing around the tubes; and a passage forming member provided between a first header tank of the header tanks, which is arranged so as to be overlapped, and a second header tank of the header tanks, which is arranged so as to be overlapped, wherein the first header tank and the second header tank each has, at a mutually facing portion thereof, a tank side hole, the passage forming member has a communication hole, the communication hole being configured to allow mutually facing tank side holes of the tank side hole to communicate with each other, and a first hole of the tank side hole and the communication hole is an elongated hole having a length longer than a length of a second hole of the tank side hole and the communication hole in the tank-length direction, the first hole being configured to communicate with the second hole in a plurality of number.

In the heat exchanger of the above aspect, the communication between the tank side hole of the first header tank and the tank side hole of the second header tank, which are arranged so as to be overlapped, is allowed by the communication hole of the passage forming member that is provided between both of the header tanks. Therefore, the communication passage that allows the communication between the first header tank and the second header tank can be formed by the communication hole of the passage forming member that is provided between the first header tank and the second header tank. With such a configuration, the distribution portion communication portion, the intermediate tank portion, and the collection portion communication portion for allowing the communication between the first header tank and the second header tank are not required. Therefore, it is possible to provide the heat exchanger capable of simplifying the structure for allowing the heat transfer medium to flow.

In the following, a heat exchangeraccording to embodiments of the present invention will be described with reference to the drawings.

An overall configuration of the heat exchangerwill be described first with reference to.is a perspective view of the heat exchangeraccording to the embodiment of the present invention.

The heat exchangeris installed in a vehicle (not shown). The heat exchangerperforms a heat exchange between air that is used for air-conditioning and a heat transfer medium that is circulated in an air-conditioning device (not shown) and that undergoes a phase change between a liquid phase and a gaseous phase.

Specifically, the heat exchangeris provided in an HVAC (a Heating Ventilation and Air Conditioning) unit (not shown) through which the air used for the air-conditioning passes. The heat exchangeris a condenser that, when the air-conditioning device performs a cabin-heating operation, performs the heat exchange with the air used for the air-conditioning to heat the air by condensing the heat transfer medium. The present invention is not limited thereto, and the heat exchangermay be an evaporator that, when the air-conditioning device performs a cabin-cooling operation, performs the heat exchange with the air used for the air-conditioning to cool and dehumidify the air by evaporating the heat transfer medium.

The heat exchangerhas: an upstream-side core portionthat is arranged on the upstream side of the air-flow direction; a downstream-side core portionthat is arranged on the downstream side of the air-flow direction; and reinforcing membersthat are respectively provided on both end portions of the heat exchanger. The upstream-side core portionand the downstream-side core portionare arranged so as to be overlapped with each other in the air-flow direction.

The upstream-side core portionand the downstream-side core portionare provided with: a pair of header tanksthat extend in the lateral direction; a plurality of tubesthat are provided between the header tanksforming the pair; and fins (not shown) that are provided between the tubes. The header tanks, the tubes, and the fins that are provided between the tubesare made of a metal such as aluminum and are integrally joined to each other by brazing, etc.

In addition, the heat exchangeris provided with passage forming membersthat are provided between the header tanksof the upstream-side core portionand the header tanksof the downstream-side core portion, which are arranged so as to be overlapped with each other.

The upstream-side core portionis divided at the central portion in the arrangement direction of the tubesand has a first divided core portionand a second divided core portion, each having independent flow path for the heat transfer medium. The downstream-side core portionis divided at the central portion in the arrangement direction of the tubesand has a third divided core portionand a fourth divided core portion, each having independent flow path of the heat transfer medium.

The respective tubesprovided on the respective core portionsandconnect the header tanksof the respective core portionsandto each other and performs the heat exchange between the heat transfer medium that flows inside the tubesand the air that flows around the tubes.

The respective core portionsandare provided so as to intersect with the air-flow direction such that the air can flow between the respective tubes. The respective core portionsandare provided so as to be overlapped with each other in the air-flow direction such that the air can flow through in a consecutive manner. In the heat exchangerof this embodiment, although two core portionsandare provided side by side to form two layers arranged in the front and rear direction, the number of the core portions is not limited to two and a plurality of core portions may be provided.

The tubesare arranged side by side in parallel, thereby being layered with interval gaps. The tubesare each formed to have a flat shape and are layered in the thickness direction. The fins are respectively provided in interval gaps between adjacent tubes. The tubesare layered in the direction that intersects with the air-flow direction. The tubesis formed with an inner flow passage through which the heat transfer medium flows.

The fins are provided between the adjacent tubes, and are layered alternately with the tubes. The fins are formed to have a wave-like shape along the longitudinal direction of the tubesand are joined to two adjacent tubes. The air supplied by a blower (not shown) of the air-conditioning device flows around the plurality of tubesand the fins. Therefore, the heat transfer medium that flows inside the tubescan undergo the heat exchange with the air via surfaces of the tubesand the fins. As described above, the fins promote the heat exchange between the heat transfer medium and the air.

The reinforcing membersare respectively provided on both end portions of the upstream-side core portionand the downstream-side core portion. The reinforcing membersare in contact with the fins that are provided on both end portions of the upstream-side core portionand the downstream-side core portion. End portions of the reinforcing membersin the longitudinal direction are respectively engaged with the header tanks, thereby linking and reinforcing between the pair of header tanks. When the tubesand the fins are brazed to form the upstream-side core portionand the downstream-side core portion, the reinforcing membersare integrated with the upstream-side core portionand the downstream-side core portionby being brazed to the fins.

An interior of each of the header tanksof the upstream-side core portionis divided at the central portion in the arrangement direction of the tubes, and the header tankshave a first upper header tankthat forms the first divided core portionand a second upper header tankthat forms the second divided core portion. In addition, the header tanksof the upstream-side core portionhas a first lower header tank (not shown) that forms the first divided core portionand a second lower header tankthat forms the second divided core portion. The first lower header tank and the second lower header tankare internally communicated. In this embodiment, although a case in which the first lower header tank and the second lower header tankare separate bodies will be described, this embodiment is not limited thereto. For example, the first lower header tank and the second lower header tankmay be integrated into a single unit.

An interior of each of the header tanksof the downstream-side core portionis divided at the central portion in the arrangement direction of the tubes, and the header tankshave a third upper header tankthat forms the third divided core portionand a fourth upper header tankthat forms the fourth divided core portion. In addition, the header tanksof the downstream-side core portionhave a third lower header tankthat forms the third divided core portionand a fourth lower header tankthat forms the fourth divided core portion. The third lower header tankand the fourth lower header tankare partitioned from each other.

is an enlarged view of a main part of the header tanks.is an enlarged view of a main part showing a state in which the tubesare inserted into the header tanks.is a IV-IV sectional view in.

As shown in, each of the header tankshas a tubular shape elongated in the arrangement direction of the tubes(see). Each of the upper header tanks,, (,) is formed to have a substantially rectangular cross-section. In a state in which the heat exchangeris attached, an upper surfaceof each of the upper header tanks,, (,) is formed to have a curved shape in which the center portion in the width direction is projected upwards.

As shown in, the first upper header tankand the third upper header tankeach has, at a mutually facing portion thereof, tank side holes(only the first upper header tankis shown). Similarly, the second upper header tankand the fourth upper header tankeach has, at a mutually facing portion thereof, the tank side holes. Note thatrepresentatively shows the main part of the first upper header tankof the first divided core portion.

Each of the upper header tanks, (,,) has, for example, five tank side holes. Each of the tank side holesis an elongated hole elongated in the length direction of each of the upper header tanks, (,,). The respective tank side holesare arranged at predetermined intervals in the length direction of the header tanks, and there are connecting portionsbetween adjacent tank side holes.

With such a configuration, compared with a case in which a single tank side holethat is elongated in the length direction of the header tanksis formed on each of the upper header tanks, (,,), deterioration in the rigidity of each of the upper header tanks, (,,) is suppressed.

As shown in, each of the header tankshas a plurality of tube insertion portsinto which the tubesare respectively inserted. When an imaginary regionextending in the circumferential direction of each of the header tanksthrough the connecting portionbetween the adjacent tank side holesis assumed, the tube insertion portsinclude those that open in the imaginary region(see).

As shown in, each of the tube insertion portsis formed by burring. An edge portion of each of the tube insertion portsis formed with a standing wallthat supports the inserted tubeat its peripheral surface and that reinforces the tube insertion port(see).

As shown in, a pair of the header tanksare provided for each of the core portionsandso as to face with each other. The header tanksare arranged such that both end portions of the plurality of tubesin the longitudinal direction are respectively inserted. Each of the header tankstemporarily stores the heat transfer medium.

The end portions of each of the upper header tanks,,,, the end portion of the first lower header tank, and the end portion of the third lower header tankare respectively closed by closing members. A relay memberfor relaying piping is provided at the end portion of the second lower header tankand the end portion of the fourth lower header tank.

The heat transfer medium used for the air-conditioning enters the first header tankof each of the core portionsand. The heat transfer medium that has entered the first header tankflows through each of the plurality of tubes. The heat transfer medium undergoes the heat exchange with the air while it is flowing through the tubes. The heat transfer medium that has flown through the tubesflows into the second header tankof each of the core portionsand.

As shown in, the passage forming memberis provided between the first upper header tankof the first divided core portionand the third upper header tankof the third divided core portion, which are arranged so as to be overlapped. In addition, the passage forming memberis provided between the second upper header tankof the second divided core portionand the fourth upper header tankof the fourth divided core portion, which are arranged so as to be overlapped.

is a perspective view of the passage forming member.is an explanatory diagram showing the relationship between between the header tankand the passage forming member.

As shown in, the passage forming memberis an elongated member. The passage forming memberis formed to have a Y-shaped cross-section by having a plate-shaped insertion piecethat is inserted between the core portionsand, which are arranged so as to be overlapped, and a bifurcated portionformed on an end portion of the insertion piece.

As shown in, the thickness dimension Tof the insertion pieceis greater than the thickness dimension Tof each of the header tanks.

The outer side surfaces of a first pieceand a second pieceforming the bifurcated portioneach has a curved surface that follows a curved surface of the upper surfaceof each of the upper header tanks,, (,). With such a configuration, in a state in which the insertion pieceof the passage forming memberis arranged between adjacent upper header tanks,, (,), the first pieceof the bifurcated portioncomes into surface contact with the upper surfaceof the one upper header tank, (,,). In addition, the second pieceof the bifurcated portioncomes into surface contact with the upper surfaceof the other upper header tank, (,,).

Then, in a state in which the first pieceand the second pieceof the bifurcated portionrespectively come into surface contact with the upper surfacesof the respective upper header tanks,, (,), an amount of insertion of the passage forming memberinto a gap between the adjacent upper header tanks,, (,) is determined. In addition, in this inserted state, the passage forming memberis brazed to each of the upper header tanks,, (,).

As shown in, the insertion pieceof the passage forming memberhas ten communication holesthat allow the tank side holesfacing with each other to communicate with each other. The communication holesare each an oval hole whose length dimension is shorter than that of the tank side hole, and two communication holescommunicate with a single tank side hole.

In this embodiment, although the tank side holeis made as the elongated hole whose length is longer than that of the communication hole, this embodiment is not limited thereto. For example, the communication holemay be made as an elongated hole whose length is longer than that of the tank side hole.

As shown in, the thickness dimension Tof the insertion pieceof the passage forming memberis greater than the thickness dimension Tof each of the header tanks. Therefore, in a state in which the pressure in each of the header tanksis increased, the pressure receiving area per unit length formed by an inner circumferential surface of the communication holeof the insertion pieceis greater than the pressure receiving area per unit length formed by an inner circumferential surface of the tank side holeof each of the header tanks.

Therefore, when the communication holeis made as the elongated hole, the total pressure receiving area formed by the inner circumferential surface of the communication holeis increased. Consequently, because the pressure applied to the inner circumferential surface of the communication holeis increased, the communication holemay be deformed.

Thus, in this embodiment, by making the tank side holeas the elongated hole whose length is longer than that of the communication hole, the increase in the total pressure receiving area formed by the inner circumferential surface of the communication holeis suppressed, and the deformation of the communication holeis suppressed in advance.

is a diagram showing the relationship between the tank side holeand the communication holes, andshows a state in which the passage forming memberis set between the respective upper header tanks, (,,), which are arranged so as to be overlapped.

As shown in, the length dimension Lof the tank side holeof each of the upper header tanks, (,,) is longer than the length dimension Lfrom a first endto a second endof a pair of adjacent communication holes. Specifically, the length dimension Lof the tank side holeis, for example, 0.5 mm longer than the length dimension Lfrom the first endto the second endfor the pair of adjacent communication hole.

With such a configuration, even in a case in which the passage forming memberis arranged so as to be displaced along the length direction of the respective upper header tanks, (,,), misalignment of the pair of communication holeswith respect to the tank side holeis suppressed. Thus, narrowing of a communication passage, which is formed by a communicating portion between the communication holesand the tank side holesis suppressed.

As shown in, the relay memberhas a second lower tank connection pipethat communicates with the second lower header tankand a fourth lower tank connection pipethat communicates with the fourth lower header tank. In addition, the relay memberhas a third lower tank connection pipethat communicates with the third lower header tank. Pipes (not shown), through which the heat transfer medium flows, are respectively connected to the respective connection pipes,, and.

The heat transfer medium enters the first divided core portionthrough the passage forming memberafter it has entered the third lower header tankfrom a supply pipe through the third lower tank connection pipe, flown in the tubes, and entered the third divided core portion. The heat transfer medium that has entered the first divided core portionis recovered by a recovery pipe via the first lower header tank, the second lower header tank, and the second lower tank connection pipe.

The heat transfer medium enters the second divided core portionthrough the passage forming memberafter it has entered the fourth lower header tankfrom the supply pipe through the fourth lower tank connection pipe, flown in the tubes, and entered the fourth divided core portion. The heat transfer medium that has entered the second divided core portionis recovered by the recovery pipe via the second lower header tankand the second lower tank connection pipe.

According to the embodiment mentioned above, the advantages described below are afforded.

The heat exchangeris the heat exchangerthat performs the heat exchange between the air and the heat transfer medium that undergoes the phase change between the liquid phase and the gaseous phase. The heat exchangeris provided with the core portionsandeach having: the header tanksprovided as a pair facing with each other; and the plurality of tubesconfigured to connect the header tanksto each other and performs the heat exchange between the heat transfer medium that flows inside the tubesand the air that flows around the tubes. The respective core portionsandare provided such that a plurality of core portionsandare overlapped in the air-flow direction. The heat exchangeris provided with the passage forming memberprovided between the first header tankof the header tanksand the second header tankof the header tanks, which are arranged so as to be overlapped.