JP5826479B2 - Supercharged air cooler heat exchanger - Google Patents

Description

  The present invention mainly relates to a heat exchanger for an automobile.

  More specifically, the present invention relates to a heat exchanger including a heat exchange core having a first circulation passage for a gas to be cooled and a second circulation passage for a liquid to be cooled.

  Such heat exchangers are mainly manufactured as supercharged air coolers for automotive heat engines.

  This type of heat exchanger is known, for example, from US Pat.

However, all these known heat exchangers have the disadvantage that they cannot be easily applied to vehicles or are difficult to industrialize for mass production.
In addition, the following problems occur in water-cooled heat exchangers that circulate engine coolant, that is, coolant cooled by a radiator, to cool gas, that is, intake air sucked into the engine. There are things to do.
That is, when the supercharging pressure by the supercharger rises, the temperature of the gas also rises and becomes high temperature. When this high temperature gas is cooled by a water-cooled heat exchanger, the heat exchange core Since the temperature of the coolant circulating in the interior rises and the coolant that has become hot returns to the engine and the radiator, they may cause problems such as overheating. In order to prevent this, the supercharging pressure by the supercharger can be set to a low value to suppress the temperature rise of the gas, or the capacity of the radiator can be increased, but this will reduce the engine output. Invite people or increase the size of the radiator.

German Published Patent No. 19902504 JP-A-10-238969 German Published Patent No. 19927607 German Published Patent No. 19511991 JP-A-11-193998 EP published patent No. 0992756

  The object of the present invention is to overcome the aforementioned drawbacks.

  The first object of the present invention is to provide a heat exchanger of the above-described type, which has great flexibility in use and can be applied to many engines and vehicles, and heat exchange. A heat exchanger that prevents the temperature of the coolant in the core from rising excessively and prevents the engine from causing problems such as overheating, and the radiator becoming large and costly. The second purpose is to provide it.

  Another object of the present invention is to provide a heat exchanger that is particularly suitable for an air cooler for supercharging.

  For the first object, the present invention is of the type defined in the introductory part of this specification, each being connected to two faces of the first circulation passage open to the heat exchange core. The air inflow casing and the air outflow casing each have an opening face, and an outer peripheral flange of the opening face is provided in pressure contact with the manifold to provide a heat exchanger. is there.

  Thus, the heat exchanger of the present invention includes a heat exchange core having an outer peripheral flange, and two openings through which the gas to be cooled of the heat exchange core passes are inserted into the frames of the two manifolds. ing. The two manifolds elastically support the gas inflow casing and the gas outflow casing, respectively.

  As a result, many types of heat exchangers including the same heat exchange core and gas inflow casing and outflow casing having different shapes depending on applications can be easily manufactured.

  The heat exchanger of the present invention having these characteristics can be preferably applied to engines and vehicles.

  Each manifold has a cover shape and preferably has a rectangular outer peripheral end. This outer peripheral end portion has an opening as a gas passage, one side has a contact flange that receives one surface of the heat exchange core, and the other side has a gas inflow casing or a gas outflow casing. An engagement flange is provided that surrounds a groove that receives the outer peripheral flange.

  It is advantageous if the engaging flange has a shape that can be attached by pressing the heat exchange core. This eliminates the need to use a holder in the brazing process.

  The two manifolds are preferably individually connected to two opposing faces of the heat exchange core.

  Each manifold preferably includes a masking portion for preventing the gas passage from entering the end region where the first passage of the heat exchange core is not provided.

  In a preferred embodiment of the present invention, the heat exchanging core consists of a stack of two fin plates, each of which is a first passage between the two pairs of fin plates. Between the fin plates is a second passage.

  However, the heat exchange core can also be manufactured by other suitable means, for example, a set of tubes and fins. When the heat exchange core is a fin plate, each fin plate has a rectangular shape, and has a substantially flat bottom wall defined by an outer peripheral flange and an opening through which the coolant passes from one side of the second passage to the other. Preferably, it has two end bosses.

  It is preferable to provide a rib for forming a U-shaped second circulation passage on the bottom wall of each fin plate.

  As yet another feature, each outer peripheral flange of the fin plate is formed with a clip that partially holds two fin plates of the same set for the purpose of brazing.

  It is preferable that one fin plate at the final end of the heat exchange core is provided with two nozzles for inlet and outlet of the coolant.

  Corrugated fins may be provided in the first passage of the heat exchange core.

  According to a preferred embodiment of the invention, the gas inflow casing and the gas outflow casing are molded into a selected shape, but it is convenient to mold the plastic material and produce it individually.

  However, it is also within the scope of the present invention for the two casings to be made of a metallic material such as an aluminum alloy.

  In a preferred application of the invention, the heat exchanger is manufactured as a supercharged air cooler for an automotive heat engine and the first circulation passage is used to circulate the air to be cooled.

  Individual gas inlet casings and gas outlet casings can be provided with molded nozzles. In this case, the supercharged air cooler has an independent form.

  As a modification, a nozzle made of a mold can be provided in the gas inflow casing. The gas outflow casing can also be formed as an intake diffuser for a vehicle heat engine. In this case, the supercharge air cooler is connected to the intake diffuser of the engine.

  For the second object, the present invention provides a heat exchanger having a heat exchange core having a first circulation passage through which a gas to be cooled circulates and a second circulation passage through which a coolant circulates. The two manifolds to be assembled individually to the two opening surfaces of the heat exchange core that are open to the first circulation passage and the outer peripheral flange provided on the opening surfaces are the opening surfaces of the two manifolds. A gas inflow casing and a gas outflow casing held by pressure bonding, a bypass pipe that communicates both the casings, a flow rate control valve that is provided in the bypass pipe, and that normally closes the flow path in the bypass pipe; An actuator for operating the flow control valve, and a temperature sensor detects the temperature of the gas in the gas inflow casing or the temperature of the coolant flowing out of the heat exchange core. When those temperatures are equal to or higher than a predetermined temperature, the actuator operates the flow control valve in the valve opening direction so that part of the gas in the gas inflow casing flows into the bypass pipe. The heat exchanger characterized by this is provided.

  According to the heat exchanger of the present invention having such a feature, when the temperature of the gas in the gas inflow casing or the temperature of the coolant in the coolant outflow nozzle in the heat exchange core becomes equal to or higher than a predetermined temperature. In addition, since a part of the high-temperature gas in the gas inflow casing is caused to flow into the bypass pipe, the temperature of the coolant introduced into the heat exchange core can be prevented from excessively rising and the temperature becomes high. The cooled liquid is no longer recirculated to the engine and the radiator. As a result, it is possible to prevent the engine from causing problems such as overheating or the increase in cost of the radiator due to an increase in size.

  In addition, it is preferable to project a plurality of cooling fins on the outer peripheral surface of the bypass pipe, and in this way, the bypass pipe and the gas introduced thereto are effectively cooled by the outside air.

  According to the heat exchanger of the invention described in claim 1, by combining a common heat exchanging core and a gas inflow casing or a gas outflow casing having different shapes depending on applications, it has a flexibility that can be easily and widely used. It is adaptable to many engines and vehicles.

According to the heat exchanger of the invention described in claim 17, since all of the high-temperature gas flowing into the gas inflow casing from the supercharger does not flow into the heat exchange core, it circulates through the heat exchange core. The temperature of the coolant is prevented from rising excessively, and the coolant whose temperature has risen does not return to the engine and the radiator. As a result, the thermal load on the engine and the radiator can be reduced, and it is possible to prevent the engine from causing problems such as overheating, or the radiator being enlarged and costly.
Also, in order to reduce the heat load on the engine and radiator, it is not necessary to set the supercharging pressure by the supercharger low and suppress the temperature rise of the gas in the gas inflow casing. It will end.

  In the following description of embodiments, reference is made to the accompanying drawings.

It is a perspective view of the heat exchanger which is 1st Example of this invention. It is a perspective view of the core for heat exchange of the heat exchanger of FIG. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. It is sectional drawing in line IV-IV of FIG. FIG. 5 is a cross-sectional view taken along line VV in FIG. 2. It is a perspective view before a manifold is assembled with the core for heat exchange of FIG. FIG. 7 is a perspective view similar to FIG. 6, showing a heat exchange core including two manifolds and two nozzles for inflow and outflow of coolant. It is a disassembled perspective view before assembling an air inflow casing and an air outflow casing to the core for heat exchange of FIG. It is a perspective view of the heat exchanger which is 2nd Example of this invention. It is a perspective view of the heat exchanger which is 3rd Example of this invention. It is a partially notched top view of the principal part of the heat exchanger of FIG.

  The heat exchanger of the first embodiment shown in FIG. 1 includes a heat exchanging core 10, and the heat exchanging core 10 is formed by assembling fin plates as described later. The heat exchange core 10 is provided with a coolant inflow nozzle 12 and an outflow nozzle 14. Openings on both sides of the heat exchange core 10 are covered with a gas inflow casing 16 and a gas outflow casing 18, respectively. A gas inflow nozzle 20 and a gas outflow nozzle 22 are attached to the gas inflow casing 16 and the gas outflow casing 18, respectively.

  The casing 16 and the casing 18 and the respective nozzles 20 and 22 are manufactured in a desired shape by molding, and are assembled to the respective sides of the heat exchange core 10 via the respective manifolds 24 and 26. Casing 16 and casing 18 are assembled into manifolds 24 and 26 by crimping.

  The cooled gas flows from the gas inflow nozzle 20 into the gas inflow casing 16, then passes through a first circulation passage (described later) of the heat exchange core 10, reaches the gas outflow casing 18, and then reaches the gas outflow nozzle. Out of 22 This gas flows into the heat exchange core 10 from the nozzle 12 and circulates in the second circulation passage (described later) of the heat exchange core 10 to exchange heat with the cooled gas, and then the heat exchange core. Cooled by the coolant flowing out from the ten nozzles 14.

  In a preferred embodiment of the invention, the heat exchanger is manufactured as a supercharged air cooler for automotive internal combustion engines. In this case, the gas to be cooled is charge air supplied from the turbo compressor and supplied to the engine through the intake diffuser. The cooling liquid is usually an engine cooling liquid.

  Next, the structure of the heat exchange core 10 will be described with reference to FIGS. In the embodiment, the heat exchange core 10 is formed by assembling the fin plate 28 by a technique known per se. However, the present invention may also comprise other types of heat exchange cores, in particular heat exchange cores having tubes and fins.

  As shown in FIG. 2, the heat exchanging core 10 includes two end plates, that is, a fin plate 28A to which the nozzles 12 and 14 are attached and a fin plate 28B on the opposite side, as a pair. The fin plates 28 that are arranged and have the same shape are stacked.

  Each fin plate 28 is generally rectangular and includes a substantially flat bottom wall 30. The bottom wall 30 has a shallow dish shape and is provided with a raised rectangular outer peripheral flange 32 at the periphery. In addition, each fin plate 28 includes two end bosses 34 and 36, which are provided with circular holes 38 and 40, respectively (FIG. 5). As can be seen more clearly from FIGS. 3 and 4, the fin plates 28 are arranged in pairs, and the bosses of each fin plate communicate with the bosses of adjacent fin plates. Thus, a fluid passage is formed between the chambers formed by each set of fin plates.

  Further, corrugated fins 42 (FIG. 3) are provided between adjacent pairs of fin plates in the heat exchange core 10. Each corrugated portion of the corrugated fin 42 is brazed to the bottom wall 30 of two opposing fin plates 28. The outer peripheral flanges 32 of the two fin plates of the same set are brazed all around in order to create a coolant circulation passage communicating with each other through each boss. Further, the short side of each fin plate is an end wall 44 bent in an inward U-shape. The end wall 44 allows the fin plates to be assembled in pairs to form a circulation path for the gas to be cooled (see the portion surrounded by the vertically long circle in FIG. 3). In this way, the corrugated fins 42 are arranged in the heat exchange core 10, and the first passage 46 for the gas to be cooled and the second passage 48 for circulating the coolant are formed (FIG. 3). And FIG. 4).

  Since the end wall 44 of the fin plate is unbroken, a passage for the gas to be cooled is created, and the gas simultaneously passes through the first passage cooled by the coolant circulating in the second passage 48. Passed through and cooled.

  As shown in FIG. 4, a clip 45 for partially assembling each set of fin plates is formed on the outer peripheral flange 32 of the fin plate 28 before brazing for final assembly.

  FIG. 5 shows that the fin plates 28 are symmetrical with each other so that the bosses can be accurately assembled during brazing, and that each boss is centrally symmetric with the adjacent fin plates. ing.

  The bosses 34A and 36A in the fin plate 28A are different from the bosses 34 and 36 in the other fin plates and have holes 38A and 40A for receiving the nozzles 12 and 14, respectively. Similarly, the fin plate 28B includes bosses 34B and 36B that are different from the others. These bosses are closed and not open.

  On the bottom wall 30 of each fin plate 28, a rib 50 is provided for making a U-shaped circulation passage in the second passage. The rib 50 is arranged in parallel with the long side of the rectangular fin plate, and has a length shorter than the long side (FIG. 2).

  As described above and as shown in FIG. 2, the heat exchanging core 10 includes two opposed opening surfaces, that is, an opening surface 52 on the gas inflow side and an opening surface 54 on the gas outflow side. The first passage 46 passes through both of the opening surfaces 52 and 54.

  As shown in the exploded view of FIG. 6, manifolds 24 and 26 are individually attached to the opening surfaces 52 and 54. The manifolds 24 and 26 have the same shape and are rectangular covers. Each manifold includes a rectangular outer peripheral end 56 and an opening for the gas passage 58 facing the opening surface 52 or the opening surface 54 of the heat exchange core 10. The manifold 24 and the manifold 26 are each provided with a masking portion 60 (FIGS. 6 and 7). The masking portion 60 prevents gas from entering the end region of the heat exchange core 10 that does not include the first passage. A corrugated fin is not provided in the terminal region of the heat exchange core 10, and a boss is provided. Thereby, the gas to be cooled is caused to flow to an effective portion of the heat exchange core 10, that is, a portion corresponding to the first passage provided with the corrugated fin.

  A contact flange 62 that receives the opening surface 52 or the opening surface 54 of the heat exchange core 10 on the side facing the heat exchange core 10 at the outer peripheral end 56 of each manifold, and the gas inflow casing 16 on the opposite side. The outer peripheral flange 68 or the pressure-contact flange 64 surrounding the groove 66 for receiving the outer peripheral flange 70 (FIG. 8) of the gas outflow casing 18 is provided. The shape of the abutment flange 62 is determined so that the heat exchange core can be compressed and attached, and a brazing holder can be dispensed with. The outer peripheral flange 68 of the gas inflow casing 16 and the outer peripheral flange 70 of the gas outflow casing 18 are received in the respective grooves 66 of the corresponding manifold 24 and the manifold 26 and are press-contacted by the corresponding press-contact flange 64. This press-contact flange is usually provided with a claw that can be folded or a knurled corrugation.

  All components of the heat exchange core 10, namely the fin plates, corrugated fins, manifold, and coolant inflow and outflow nozzles are made of aluminum alloy and assembled together in a brazing furnace. It is convenient to braze in one step. Next, the obtained heat exchanging core 10 is assembled while being in pressure contact with the gas inflow casing 16 and the gas outflow casing 18 of a desired shape.

  In the embodiment shown in FIGS. 1 to 8, the gas inflow casing 16 and the gas outflow casing 18 are each provided with a nozzle 20 and a nozzle 22, which makes it possible to manufacture an independent heat exchanger. . This heat exchanger is installed as a supercharge air cooler at a selected position below the hood of the vehicle. In this case, appropriate ducts are fixed to the nozzle 20 and the nozzle 22.

  According to the present invention, the shapes of the gas inflow casing 16 and the gas outflow casing 18 can be determined according to the structure of the vehicle or the engine.

  The gas inflow casing 16 and the gas outflow casing 18 can be made of a plastic material or an appropriate metal material such as an aluminum alloy.

  In the embodiment shown in FIG. 9, the gas inflow casing 116 is provided with a gas inflow nozzle 120 that faces in a different direction from the nozzle 20 of the above-described embodiment.

  The gas outflow casing 118 is formed as an intake diffuser for a vehicle heat engine. Thereby, although it is a heat exchanger, in this case, a supercharged air cooler, it can be directly connected to the engine without providing an intermediate duct as in the case of the embodiments of FIGS.

10 and 11 show a third embodiment of the heat exchanger of the present invention.
In this embodiment, a U-shaped bypass pipe 200 in a plan view is detachably attached to one side of the gas inflow casing 16 and the gas outflow casing 18 so as to communicate with the inside of both the casings 16, 18. A part of the gas in the inflow casing 16 can be allowed to flow into the gas outflow casing 18 by bypassing the heat exchange core 10. The bypass pipe 200 is made of, for example, an aluminum alloy, and a plurality of cooling fins 201 are integrally projected on the outer peripheral surface along the longitudinal direction.

  A butterfly-type flow rate control valve 202 is provided at an intermediate portion in the bypass pipe 200 so as to always close the flow path in the bypass pipe 200. The valve shaft 203 of the flow control valve 202 is rotatably supported by a cylindrical protrusion 204 protruding from the bypass pipe 200, and the outer end of the valve shaft 203 is attached to the open end of the cylindrical protrusion 204. An electric actuator such as a stepping motor 205 is connected to a rotating shaft (not shown).

  A temperature sensor 206 for detecting the temperature of the gas inside the gas inflow casing 16 is attached, and this temperature sensor 206 is electrically connected to the stepping motor 205 via a control device (not shown).

  In the heat exchanger of the third embodiment, when the temperature sensor 206 detects that the temperature of the gas in the gas inflow casing 16 has become equal to or higher than a predetermined temperature, the stepping motor 205 is operated to The flow rate control valve 202 that has been closed until is turned in the valve opening direction so that a part of the high-temperature gas in the gas inflow casing 16 can flow into the gas outflow casing 18 through the bypass pipe 200. ing. At this time, the stepping motor 205 may be controlled so that the flow rate control valve 202 is fully opened when the temperature of the gas in the gas inflow casing 16 reaches a predetermined temperature or more, or the gas The rising temperature of the gas in the inflow casing 16 is set stepwise in advance, and the stepping motor 205 is controlled stepwise so that the flow control valve 202 is gradually opened correspondingly to the rising temperature. You may make it do.

  Thus, when the temperature of the gas in the gas inflow casing 16 becomes equal to or higher than a predetermined temperature, a part of the high-temperature gas therein is caused to flow into the gas outflow casing 18 through the bypass pipe 200. Then, all of the high-temperature gas that has flowed into the gas inflow casing 16 from the supercharger will not flow into the heat exchange core 10. As a result, the temperature of the coolant that circulates through the heat exchange core 10 is suppressed from excessively rising, and the coolant that has reached a high temperature does not return to the engine and the radiator. It is possible to prevent the engine from causing problems such as overheating and the size of the radiator to be increased and the cost to be increased.

By the way, in order to reduce the heat load of the engine and the radiator, it is only necessary to suppress the temperature of the coolant circulating in the heat exchange core 10 from rising excessively. It is necessary to suppress the temperature rise of the gas in the gas inflow casing 16 by setting the supercharging pressure by the charger to be low. However, this is not preferable because the engine output decreases.
In the present invention, since the thermal load on the engine and the radiator is reduced by the above-described means, it is not necessary to set the supercharging pressure by the supercharger low, and therefore the output of the engine does not need to be reduced so much.

  In the above embodiment, the temperature sensor 206 is provided in the gas inflow casing 16, but is provided in the vicinity of the base of the coolant outflow nozzle 14, and the engine coolant flows out after heat exchange by the heat exchange core 10. The stepping motor 205 may be actuated by detecting the temperature. At this time, when the temperature of the coolant that is exchanged by the heat exchange core 10 and flows out becomes equal to or higher than a predetermined temperature, the stepping motor 205 is operated in the same manner as described above, and the flow control valve 202 is The valve is opened so that a part of the hot gas in the gas inflow casing 16 flows into the gas outflow casing 18 through the bypass pipe 200.

  The present invention can be preferably applied particularly to a supercharged air cooler for automobiles.

DESCRIPTION OF SYMBOLS 10 Heat exchange core 12 Coolant inflow nozzle 14 Coolant outflow nozzle 16 Gas inflow casing 18 Gas outflow casing 20 Gas inflow nozzle 22 Gas outflow nozzle 24 Manifold 26 Manifold 28 Fin plate 30 Bottom wall 32 Outer peripheral flange 34 Boss 36 Boss 38 hole 40 hole 42 corrugated fin 44 end wall 45 clip 46 first passage 48 second passage 50 rib 52 opening surface 54 opening surface 56 outer peripheral end 58 gas passage 60 masking portion 62 abutting flange 64 pressure contact flange 66 groove 68 outer peripheral flange 70 outer peripheral flange 116 gas inflow casing 118 gas outflow casing 120 gas inflow nozzle 200 bypass pipe 201 cooling fin 202 flow control valve 203 valve shaft 204 cylindrical projection 205 stepping motor (actuator) Data)
206 Temperature sensor

Claims (17)

In a heat exchanger comprising a heat exchange core (10) having a first circulation passage (46) through which a gas to be cooled circulates and a second circulation passage (48) through which a coolant circulates.
Two manifolds (24, 26) that are individually assembled to two opening surfaces (52, 54) of the heat exchange core (10) that are open to the first circulation passage (46),
And the outer peripheral flanges (68, 70) individually provided with the opening surfaces (52, 54) of the gas inflow casing (16) and the gas outflow casing (18) are crimped and held in one of the manifolds,
In order to prevent gas from entering the end region of the heat exchange core (10) where the first circulation passage (46) is not provided, a masking portion (60) is provided in each manifold (24, 26). ) Is provided.   Each of the manifolds (24, 26) has a cover shape and is provided with a rectangular outer peripheral end portion (56) having an opening (58) for a gas passage. The abutting flange (62) for receiving one surface of the gas inflow casing (16) and the groove (66) for receiving the outer flange (68, 70) of the gas inflow casing (16) or the gas outflow casing (18) on the other side are enclosed. The heat exchanger according to claim 1, further comprising a press-contact flange.   The heat exchanger according to claim 2, wherein the contact flange (62) is shaped so that the heat exchanging core can be pressed and attached.   The heat exchange according to any one of claims 1 to 3, wherein the two manifolds (24, 26) are respectively assembled to two opening surfaces (52, 54) of the core for heat exchange. vessel.   The heat exchange core (10) consists of a stack of two fin plates (28), and the first passage (46) between the two pairs of fin plates is the same. The heat exchanger according to any one of claims 1 to 4, wherein a space between the pair of fin plates is a second passage (48).   Each fin plate (28) of the heat exchange core (10) has a rectangular shape and is divided by an outer peripheral flange (32). 6. A heat exchanger according to claim 5, characterized in that it comprises two end bosses (34, 36) having openings (38, 40) through which the coolant passes.   The heat exchanger according to claim 6, wherein a U-shaped second circulation passage is formed by a rib (50) of the bottom wall (30) of each fin plate (28). A clip ( 45 ) that partially holds two fin plates of the same set is formed on the outer peripheral flange (32) of each fin plate (28) for joining by brazing. The heat exchanger according to claim 6 or 7.   The two fins (12, 14) for cooling liquid inlet and outlet are provided on one fin plate (28A) at the last part of the heat exchange core (10). The heat exchanger in any one of 5-8.   The heat exchanger according to any one of claims 5 to 9, wherein the heat exchange core (10) includes corrugated fins (42) individually in the first passage (46).   The heat exchanger according to any one of claims 1 to 10, wherein the gas inflow casing (16) and the gas outflow casing (18) are manufactured in a selected shape by a mold.   The heat exchanger according to any one of claims 1 to 11, wherein both the gas inflow casing (16) and the gas outflow casing (18) are manufactured by a mold made of a plastic material.   13. Manufactured as a supercharged air cooler for a motor vehicle engine, the first circulation passage (46) is used for circulating the air to be cooled. The heat exchanger in any one of.   The heat exchanger according to claim 13, characterized in that the gas inflow casing (16) and the gas outflow casing (18) are each provided with nozzles (20), (22) made of a mold.   14. The gas inflow casing (116) comprises a nozzle (120) made of mold, while the gas outflow casing (118) is formed as an intake diffuser for a vehicle heat engine. The described heat exchanger. In a heat exchanger comprising a heat exchange core (10) having a first circulation passage (46) through which a gas to be cooled circulates and a second circulation passage (48) through which a coolant circulates.
Two manifolds (24, 26) individually assembled to two opening surfaces (52, 54) of the heat exchange core (10), which are open to the first circulation passage (46); A gas inflow casing (16) and a gas outflow casing (16) in which outer peripheral flanges (68, 70) provided on the opening surfaces (52, 54) are pressure-bonded and held on the opening surfaces (52, 54) of the manifolds (24, 26). 18), a bypass pipe (200) for communicating the two casings (16, 18), and the bypass pipe (200), and the flow path in the bypass pipe (200) is normally closed. A flow control valve (202), and an actuator (205) for operating the flow control valve (202),
When the temperature of the gas in the gas inflow casing (16) or the temperature of the coolant flowing out from the heat exchange core (10) is detected by the temperature sensor (206), and those temperatures are equal to or higher than a predetermined temperature. The actuator (205) operates the flow rate control valve (202) in the valve opening direction so that a part of the gas in the gas inflow casing (16) flows into the bypass pipe (200),
In order to prevent gas from entering the end region of the heat exchange core (10) where the first circulation passage (46) is not provided, a masking portion (60) is provided in each manifold (24, 26). ) Is provided.   The heat exchanger according to claim 16, wherein a plurality of cooling fins (201) are provided so as to protrude from an outer peripheral surface of the bypass pipe (200).

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