Heat Exchanger for Vehicle and Vehicle

This application claims priority to Japanese Patent Application No. 2024-075214 filed on May 7, 2024, incorporated herein by reference in its entirety.

The present specification discloses a heat exchanger mounted on a vehicle, and a vehicle provided with the heat exchanger.

A fan or a power source (for example, a motor or an engine) mounted on a vehicle generates noise along with its operation. There is a request to suppress the leakage of operation noise of the fan or the power source to the outside of the vehicle.

For example, Japanese Unexamined Patent Application Publication No. 2007-285592 (JP 2007-285592 A) discloses a heat exchanger that suppresses the leakage of operation noise of a power source to the outside of a vehicle. The heat exchanger includes a plurality of fins and louvers attached to the fins. The louvers face the direction of a sound source. With such a configuration, a part of the sound generated from the sound source is reflected by the louvers, reducing the sound leaking to the outside of the vehicle.

In JP 2007-285592 A, however, another part of the sound generated from the sound source leaks to the outside of the vehicle through a passage formed between adjacent fins. Therefore, the technique of JP 2007-285592 A cannot sufficiently suppress the operation noise of the fan or the power source.

Thus, the present specification discloses a heat exchanger and a vehicle capable of more effectively suppressing the leakage of operation noise of an in-vehicle component to the outside of a vehicle.

An aspect of the present disclosure provides a heat exchanger for a vehicle, including:

In this case, the fins may be shaped to be periodically undulated in the second direction in a course of extending in the vehicle front-rear direction, and shaped and arranged to be a mirror image in the second direction with respect to the other adjacent fins; and

A portion of the fins may be inclined or curved with respect to the front-rear direction and the second direction such that the dimension of the expansion chamber in the second direction continuously varies at both end portions of the expansion chamber in the front-rear direction.

The air guide passage may include a plurality of types of the expansion chambers with different dimensions in the front-rear direction; and

An aspect of the present disclosure provides a vehicle including the heat exchanger described above, in which:

According to the technique disclosed in the present specification, the dimension of the air guide passage in the second direction is locally increased. Consequently, the air guide passage functions as an expandable silencer, effectively reducing noise from the sound source.

Hereinafter, the vehicleon which the heat exchangerand the heat exchangerare mounted will be described with reference to the drawings.is a diagram schematically showing the arrangement and shape of a heat exchanger. In the drawings, “Fr”, “Up”, and “Rh” indicate the front, upper, and right sides of the vehicles, respectively.

As shown in the upper part of, a power unit chamber, which is a space in which a power source (for example, a motor or an engine) is disposed, is located in a front part of the vehicle. A heat exchangerthat exchanges heat between the refrigerant and the outside air is disposed in the power unit chamber. The heat exchangerhas a flat rectangular shape and is fixed to the power unit chamberin an upright posture such that the thickness direction thereof is substantially parallel to the vehicle front-rear direction. The heat exchangeris, for example, a radiator or an intercooler. The refrigerant flowing through the heat exchangermay be, for example, an air-conditioning refrigerant or coolant that cools a power source. The number of the heat exchangersmounted on the vehicleis not limited, and may be one or two or more.

A grilleis disposed in front of the heat exchanger, and a sound sourceis disposed behind the heat exchanger. An air guide ductis disposed between the heat exchangerand the grille, and the outside air is efficiently guided to the heat exchangerby the air guide duct. The sound sourceis an in-vehicle component that generates noise as the vehicleis driven. The sound sourceis, for example, an electric fan that attracts outside air, a power source, or a combination thereof.

In the related art, noise generated in the sound sourcemay pass through the heat exchangerand leak out of the vehicle. The heat exchangerdisclosed herein effectively suppresses such noise leakage. Hereinafter, the configuration of the heat exchangerwill be described in detail.

As shown in the lower part of, the heat exchangerincludes a core, tanksdisposed on both sides of the core, and a framethat holds the coreand the tank. The tankis a container for temporarily storing a refrigerant. Each tankcommunicates with a tubeto be described later. A refrigerant inletis provided in one of the two tanks, and a refrigerant outletis provided in the other of the two tanks. The refrigerant is heat exchanged with the outside air in the process from the refrigerant inletto the refrigerant outletthrough the tube.

The coreincludes a plurality of tubesand a plurality of fins. The tubeis a flat hollow member, and the refrigerant flows inside the tube. As shown in, the tubeextends in the vehicle width direction from one tanktoward the other tank. In addition, a plurality of tubesare arranged at intervals in the vertical direction. The tubeis made of a metal having high thermal conductivity, for example, aluminum. Hereinafter, the space between the two tubesadjacent to each other in the up-down direction is referred to as a “fin space”.

In each fin space, a plurality of finsare arranged at intervals in the vehicle width direction. Hereinafter, the arrangement direction of the plurality of tubesis referred to as a “first direction”, and the arrangement direction of the plurality of finsis referred to as a “second direction”. The finis a plate member arranged in a posture in which the thickness direction thereof is parallel to the vehicle width direction (that is, the second direction), and is a partition wall that divides the fin spaceinto small spaces. Like the tube, the finis made of a metal having a high thermal conductivity, for example, aluminum. Further, the upper end and the lower end of each finare fixed to the tubeby brazing or the like. The space between the two finsadjacent to each other in the second direction functions as the air guide passagethrough which the outside air passes. The air guide passageis a passage extending in the front-rear direction and having both ends opened in the front-rear direction.

Heretofore, noise generated in the sound sourceleaks to the outside of the vehicle through the air guide passage. In the heat exchangerdisclosed herein, cach of the finsis raised and lowered in the second direction in order to suppress the leakage of the noise. This will be described with reference to.

is a cross-sectional A-A view of. Note that a broken line arrow inindicates the flow of the wind in the air guide passage. As shown in, the finhas a shape that is periodically raised and lowered in the second direction (that is, the vehicle width direction) in the process of advancing in the vehicle front-rear direction. In other words, the finsare shaped to be locally separated from the other adjacent finsin the process of advancing in the front-rear direction so that the second direction dimension of the air guide passageis locally expanded. In addition, the two finsadjacent to each other in the second direction are shaped and arranged so as to be mirror images of each other. With such a configuration, the air guide passagehas a shape in which the pipe portionand the expansion chamberhaving a larger second direction dimension than the pipe portionare alternately arranged in the front-rear direction.

By forming the expansion chamberin which the cross-sectional area is locally increased in the air guide passageas described above, noise can be reduced. This will be described with reference to.is a schematic view showing a state of the sound wavepassing through the expansion chamber. When the air guide passageis provided with the expansion chamber, the air guide passagefunctions as an expansion type silencer in which a part of the pipe is expanded.

That is, when the expansion chamberis provided in the air guide passage, the fluid flowing in the air guide passageexpands in the air guide passage, and the velocity and pressure of the fluid decrease. Along with this, reflection and interference of the sound wavesoccur in the expansion chamber, and the energy of the sound is consumed. This in turn significantly reduces the level of the sound. Here, the reduced volume R when the sound passes through the expansion chambercan be expressed by the following Expression 1.

In Expression 1, Sis the cross-sectional area of the pipe portion, Sis the cross-sectional area of the expansion chamber, and L is the length of the expansion chamber. Further, ω is the wavelength of the sound wave, and c is the speed of sound. As is apparent from Equation 1, the reduced volume R is determined by the cross-sectional area ratio m of the expansion chamberwith respect to the pipe portionand the length L of the expansion chamber. Therefore, by designing the cross-sectional area ratio m and the length L in accordance with the frequency of the noise to be muffled and the volume of the reduced volume R, efficient sound reduction can be achieved. As a result, it is possible to effectively suppress the leakage of the noise emitted from the sound sourceto the outside of the vehicle.

Incidentally, as shown in, in the present example, the expansion chamberof the air guide passagehas a substantially hexagonal shape instead of a quadrangular shape in plan view. In other words, a portion of the finis inclined with respect to the front-rear direction and the second direction so that the second direction dimension of the expansion chambercontinuously changes at both ends in the front-rear direction of the expansion chamber. With such a configuration, it is possible to reduce the resistance of the wind flowing through the air guide passageas compared with the case where the expansion chamberhas a substantially rectangular shape. As a result, the efficiency of heat exchange between the refrigerant flowing through the tubeand the outside air can be further improved. Note that, as long as the resistance of the outside air flowing through the air guide passagecan be suppressed, a portion of the finmay be curved in a plan view instead of being inclined in a plan view. For example, the expansion chambermay be substantially circular in plan view, rather than substantially polygonal.

Further, as is apparent from the above description, the finhas a shape that is raised and lowered in the second direction. With such a shape, the cross-sectional coefficient of the finis improved, and the rigidity of the finand thus the heat exchangeris increased. Further, since the finof the present example has a shape that is raised and lowered in the second direction, the surface area is increased as compared with the conventional fin. This further improves the heat exchange efficiency between the outside air and the refrigerant.

Incidentally, depending on the vehicle type, as shown in the upper stage of, the heat exchangermay be arranged in an inclined posture such that the upper end is located behind the vehicle from the lower end. With such an arrangement, the degree of freedom in design of the front portion of the vehicleis improved, and the aerodynamic performance around the hood is also improved.

Even when the heat exchangeris arranged in an inclined posture, the air guide passageis made parallel to the vehicle front-rear direction. That is, the tubeis inclined with respect to the thickness direction of the heat exchangerso that its upper surface is substantially horizontal. In addition, a beadis formed in the finto raise and lower the finin the second direction. The beadextends in a direction parallel to the up-down direction and is inclined with respect to the frameof the heat exchanger.

With such a configuration, even when the heat exchangeris arranged in an inclined posture, the air guide passageextends in the front-rear direction, and the pipe portionand the expansion chamberare alternately arranged in the front-rear direction. Thus, even if the heat exchangeris inclined, the noise from the sound sourcecan be efficiently muted.

Note that the configuration described above is merely an example, and other configurations may be changed as long as the configuration described in claimis provided. For example, in the above description, the plurality of tubesare arranged in the up-down direction, and the plurality of finsare arranged in the vehicle width direction. However, as illustrated in, the plurality of tubesmay be arranged in the vehicle width direction, and the plurality of finsmay be arranged in the vertical direction. In this case, the vehicle width direction is the “first direction”, and the vertical direction is the “second direction”.

When the plurality of finsare arranged in the up-down direction, cach finmay have a shape that is raised and lowered in the up-down direction, that is, in the second direction in the process of advancing in the front-rear direction. In this case, water may accumulate in a portion of each finthat bulges downward. Therefore, in the case where the plurality of finsare arranged in the vertical direction, the drain holemay be formed at a position where each finbulges downward.

Further, the shape of the expansion chambermay be changed according to the position where the expansion chamberis provided. For example, as shown in the upper part of, the length L of the expansion chambermay be changed according to the position in the front-rear direction. With this configuration, it is possible to efficiently mute sounds of a plurality of types of frequencies. For example, in the upper case of, the length Lof the second expansion chamberis larger than the length Lof the first expansion chamberHere, the first expansion chambercan effectively mute sounds in the first frequency range, and the second expansion chambercan efficiently mute sounds in the second frequency range lower than the first frequency range. Therefore, by mixing expansion chambershaving different lengths L in one heat exchanger, sounds in a wider frequency range can be efficiently muted.

In, two types of expansion chambershaving different lengths L are mixed in one air guide passage. However, the length L of the expansion chambermay be changed for each air guide passage. For example, the length L of the expansion chamberof the first air guide passageand the length L of the expansion chamberof the second air guide passagedifferent from the first air guide passagemay be changed from each other. Even with such a configuration, it is possible to widen the frequency range in which the sound can be muted. However, in this case, it is necessary to prepare a plurality of types of finshaving different shapes (in particular, the length L of the expansion chamber), and the number of types of components increases. On the other hand, as shown in the upper part of, two types of expansion chambershaving different lengths L are intermingled in one air guide passage, while the plurality of finshave the same or symmetrical shapes, whereby the number of types of finscan be suppressed to be small.

Incidentally, as is clear from Equation 1, in order to increase the reduced volume R, it is sufficient to increase the cross-sectional area ratio m. Further, in order to increase the cross-sectional area ratio m, the second direction dimension (hereinafter referred to as “width D”) of the pipe portionmay be reduced, or the second direction dimension (hereinafter referred to as “width D”) of the expansion chambermay be increased. However, when the width DI of the pipe portionis reduced or the width Dof the expansion chamberis increased, the flow rate of the outside air decreases accordingly, and consequently, the heat-exchange efficiency decreases. Therefore, the width Dof the pipe portionand the width Dof the expansion chambermay be determined by considering the balance between the outside air flow rate required for heat-exchange and the reduced volume R required for noise suppression.

Further, as shown in the lower part of, the shape of the front end portion of each finmay be adjusted so that the arrangement interval W of the plurality of finsin the second direction is uniform at the front end of the heat exchanger. With such a configuration, the appearance of the heat exchangervisible through the grilleis improved. In the above description, the expansion chamberand the pipe portionare periodically arranged in the front-rear direction as an example. However, the expansion chambermay be arranged irregularly as long as the second direction dimension of the air guide passagelocally increases.