Air conditioning device for vehicle

An air conditioning device for a vehicle (1) includes: a housing (2) having an opening (2M); a blower (4) having a fan (9) accommodated within the housing and rotating about a rotation axis parallel to a first axis; a filter section (5) which is disposed between a gas inlet (7) and the opening and through which gas taken in from the gas inlet and flowing into the opening passes; and a support member (6) disposed between the blower and the filter section so as to be located at least partially at the opening, and supporting the filter section. The support member has a rib portion (61) extending in a longitudinal direction in a predetermined plane orthogonal to the first axis, and a sticking-out portion (62) sticking out from the rib portion in a transverse direction in the predetermined plane orthogonal to the longitudinal direction.

TECHNICAL FIELD

The present invention relates to an air conditioning device for a vehicle.

BACKGROUND ART

An air conditioning device for a vehicle is provided in a vehicle, as a heating, ventilating, and air conditioning (HVAC) unit. The air conditioning device for a vehicle includes a filter section disposed upstream of a blower and improves quality of air in the vehicle by collecting foreign substances and the like with the filter section. When air flows due to the blower being activated, the filter section may be deformed by force of the air so as to warp toward the blower. Thus, a support member is provided that suppresses the warping of the filter section, as disclosed in Patent Document 1.

CITATION LIST

Patent Document

Patent Document 1: JP 08-215528 A

SUMMARY OF INVENTION

Technical Problems

In a case where air flows around the support member, NZ sound may be amplified, causing an unpleasant noise, depending on the structure of the support member. NZ sound refers to narrow-band noise generated in correlation with the rotational speed (N) of the blower and the number (Z) of fans, and is considered to be generated by an unbalanced flow rate or pressure of the air flowing into the blower.

An object of the present invention is to provide an air conditioning device for a vehicle capable of reducing noise generation.

Solution to Problems

An embodiment of the present invention provides an air conditioning device for a vehicle, including: a housing including an opening; a blower including a fan accommodated in the housing, the fan rotating about a rotation axis parallel to a first axis; a filter section disposed between a gas inlet and the opening, gas taken in from the gas inlet and flowing into the opening passing through the filer section; and a support member disposed between the blower and the filter section located at least partially at the opening, the support member supporting the filter section. The support member includes a rib portion extending in a longitudinal direction in a predetermined plane orthogonal to the first axis and a sticking-out portion sticking out from the rib portion in a transverse direction in the predetermined plane and orthogonal to the longitudinal direction.

According to an embodiment of the present invention, even in a case where force of gas flowing from the gas inlet through the filter section to the opening causes the filter section to warp, the support member located at least partially at the opening suppresses warping of the filter section. The inventors have found that even in a case where air flows around the support member, the sticking-out portion of the support member can reduce noise generation. According to the finding of the inventors, the sticking-out portion provided disturbs the flow of gas around the support member. As a result, it is assumed that generation of a gas stagnation portion is suppressed, an unbalanced flow rate or pressure of gas flowing into the blower is prevented, and generation of noise, such as NZ sound, is reduced. Furthermore, according to an embodiment of the present invention, the rib portion provided maintains rigidity of the support member extending in the longitudinal direction.

In an embodiment of the present invention, the support member is preferably affixed to the housing so as to be located at the center of the opening.

The support member located at the center of the opening effectively suppresses warping of the filter section.

In an embodiment of the present invention, the air conditioning device for a vehicle preferably includes a damper capable of rotating about a rotation axis parallel to a second axis in the predetermined plane, the damper opening and closing the gas inlet; the rotation axis of the fan is preferably orthogonal to the rotation axis of the damper; and the gas inlet is preferably arranged away from the rotation axis of the damper in a direction parallel to a third axis in the predetermined plane orthogonal to the second axis.

A vehicle is provided with a gas inlet taking in outside air and a gas inlet taking in inside air, and the damper rotating about the rotation axis and switching intake of the outside air and intake of the inside air. In a case where the gas inlet is disposed away from the rotation axis of the damper in the direction parallel to the third axis, at least part of gas flowing from the gas inlet toward the opening collides with the support member diagonally. The inventors have found that in consideration of such positional relationship between the gas inlet and the support member, providing the sticking-out portion in the support member can effectively reduce noise generation.

In the present invention, the longitudinal direction is preferably parallel to the second axis.

The inventors have found that with the longitudinal direction of the support member being parallel to the rotation axis of the damper, the sticking-out portion sticking out from the rib in the direction parallel to the third axis can effectively reduce noise generation.

In an embodiment of the present invention, the sticking-out portion preferably sticks out from the rib portion toward both sides in the transverse direction.

The inventors have found that the sticking-out portion disposed on both sides of the rib can reduce noise generation more effectively.

In an embodiment of the present invention, the sticking-out portion preferably includes first portions and second portions, a sticking-out amount of the first portions from the rib portion being a first dimension, a sticking-out amount of the second portions from the rib portion being a second dimension different from the first dimension. The first portions and the second portions are preferably disposed alternately in the longitudinal direction.

The first portions and the second portions are disposed alternately in the longitudinal direction of the support member, so that recesses and projections are provided at ends of the sticking-out portion. This configuration can effectively reduce noise generation. It is assumed that noise generation can be effectively reduced because the recesses and projections provided at the ends of the sticking-out portion further disturb the flow of gas.

In an embodiment of the present invention, the sticking-out portion preferably includes third portions and fourth portions, a dimension of the third portions in a direction parallel to the first axis being a third dimension, a dimension of the fourth portions in the direction parallel to the first axis being a fourth dimension different from the third dimension. The third portions and the fourth portions are preferably disposed alternately in the longitudinal direction.

The third portions and the fourth portions are disposed alternately in the longitudinal direction of the support member, so that recesses and projections are provided on the upper surface or lower surface of the sticking-out portion. This configuration can also reduce noise generation effectively. It is also assumed that noise generation can be effectively reduced because the recesses and projections provided on the upper surface or lower surface of the sticking-out portion further disturb the flow of gas.

Advantageous Effects of Invention

The present invention provides an air conditioning device for a vehicle capable of reducing noise generation.

DESCRIPTION OF EMBODIMENTS

Embodiments according to the present invention will be described below with reference to the accompanying drawings. However, the present invention is not limited to these embodiments. The constituent elements of the embodiments described below can be combined with each other as desired. Furthermore, some constituent elements may not be used in some cases.

In the following description, an XYZ Cartesian coordinate system is set, and positional relationships of the constituents are stated while referencing this XYZ Cartesian coordinate system. The Z axis (first axis), Y axis (second axis), and X axis (third axis) are orthogonal to each other. The XY plane (predetermined plane) includes the X axis and Y axis and is orthogonal to the Z axis. In the following description, the +Z direction is referred to as “above”, and the −Z direction is referred to as “below”, where appropriate.

First Embodiment

A first embodiment of the present invention will be described below.FIG. 1is a cross-sectional view schematically illustrating an example of an air conditioning device for a vehicle1according to the present embodiment.FIG. 2is a top view of a housing2according to the present embodiment, taken along line A-A inFIG. 1.

As illustrated inFIGS. 1 and 2, the air conditioning device for a vehicle1includes the housing2, an inside/outside air switching box3disposed above the housing2, a blower4at least partially accommodated in the housing2, a filter section5accommodated in the inside/outside air switching box3, and a support member6supporting the filter section5.

The housing2includes an opening2M from which air, being gas, flows in and an upper surface2T arranged in the periphery of the opening2M. The upper surface2T faces the filter section5. The upper surface2T includes a curved surface, and the opening2M has a bell-mouth shape.

The inside/outside air switching box3includes a gas inlet7taking in air and a damper8opening and closing the gas inlet7. The gas inlet7includes an outside air inlet7A taking in outside air being air outside the vehicle and an inside air inlet7B taking in inside air being air inside the vehicle. The damper8is accommodated in the inside/outside air switching box3, and opens either one of the outside air inlet7A and the inside air inlet7B and closes the other to switch intake of outside air and intake of inside air.

The damper8can rotate about a rotation axis BX parallel to the Y axis. The damper8rotates about the rotation axis BX to open either one of the outside air inlet7A and the inside air inlet7B and close the other.

The inside of the inside/outside air switching box3and the inside of the housing2are in connection with each other through the opening2M. Air taken in from the gas inlet7flows into the housing2through the opening2M.

The blower4includes a fan9accommodated in the housing2and a motor10generating motive power for rotating the fan9. The fan9is a sirocco fan and rotates about a rotation axis AX parallel to the Z axis by operation of the motor10. When the blower4is activated, the air taken into the inside/outside air switching box3from the gas inlet7flows into the housing2through the filter section5and the opening2M.

The filter section5is disposed between the gas inlet7and the opening2M. The air taken in from the gas inlet7passes through the filter section5and flows into the opening2M. The filter section5includes a filter5F composed of, for example, filter paper, and collects foreign substances and the like in the air taken in from the gas inlet7.

The filter section5is disposed above the housing2. The lower surface of the filter section5is away from the upper surface2T of the housing2. This configuration suppresses an increase in ventilation resistance at the circumferential edge of the filter section5. The upper surface of the filter section5is arranged at a height so as not to come into contact with the damper8.

The support member6is disposed between the blower4and the filter section5and supports the lower surface of the filter section5. Force of gas flowing from the gas inlet7toward the opening2M may cause the filter section5to warp downward. The support member6supports the filter section5so that the filter section5does not warp downward.

As illustrated inFIG. 2, the support member6is a rod-like member and extends in a predetermined direction in the XY plane. In the following description, the extending direction of the support member6is referred to as “longitudinal direction”, and a direction in the XY plane orthogonal to the longitudinal direction is referred to as “transverse direction”, where appropriate.

In the present embodiment, the longitudinal direction of the support member6is parallel to the Y axis, and the transverse direction of the support member6is parallel to the X axis.

The support member6is affixed to the housing2. In the present embodiment, only one support member6is provided across the opening2M. The support member6is located at least partially at the opening2M.

In the XY plane, the opening2M is circular, and the center of the opening2M is orthogonal to the rotation axis AX of the fan9. The center of the opening2M is located coinciding with the rotation axis AX in the XY plane. A first end and a second end of the support member6are affixed to the housing2so that the central portion of the support member6in the longitudinal direction is located at the center of the opening2M.

The rotation axis AX of the fan9is orthogonal to the rotation axis BX of the damper8. In the XY plane, the rotation axis AX and the rotation axis BX overlap each other. The support member6is disposed directly below the rotation axis BX of the damper8.

The support member6includes a rib portion61extending in the longitudinal direction and a sticking-out portion62sticking out from the rib portion61in the transverse direction. As illustrated inFIG. 1, in a cross section orthogonal to the longitudinal direction of the support member6, the rib portion61has a cross section having a rectangular shape longer in the Z-axis direction, and the sticking-out portion62has a cross section having a rectangular shape longer in the X-axis direction.

In the present embodiment, the sticking-out portion62sticks out from the lower end (end on the −Z side) of the rib portion61in the transverse direction. In the present embodiment, the sticking-out portion62sticks out from the rib portion61toward both sides in the transverse direction. The sticking-out amount of the sticking-out portion62on the +X side is equal to the sticking-out amount of the sticking-out portion62on the −X side.

InFIG. 1, t indicates the sticking-out amount of the sticking-out portion62from the rib portion61, and D indicates a dimension of the opening2M. The shape of the support member6is determined so that Relationship (1) below is satisfied.
1%≤t/D≤5%  (1)

Note that t/D is preferably 2.5%. The sticking-out amount t refers to the distance in the transverse direction between the leading end of the sticking-out portion62in the transverse direction and the interface portion between the sticking-out portion62and the rib portion61. The dimension D of the opening2M refers to the diameter of the opening2M in the XY plane.

Furthermore, T indicates a dimension of the sticking-out portion62in the transverse direction of the support member6, and D indicates the dimension of the opening2M. The shape of the support member6is determined so that Relationship (2) below is satisfied.
5%≤T/D≤15%  (2)

Note that T/D is preferably 7%. The dimension T of the sticking-out portion62refers to the distance between a first leading end and a second leading end of the sticking-out portion62in the transverse direction.

As illustrated inFIG. 1, the gas inlet7is arranged away from the rotation axis BX of the damper8in the X-axis direction. The outside air inlet7A is arranged on the −X side of the rotation axis BX, and the inside air inlet7B is arranged on the +X side of the rotation axis BX. In the XY plane, the gas inlet7and the support member6do not overlap each other, and the support member6is arranged in a position that is not directly below the gas inlet7. The air taken in from the gas inlet7collides with the support member6diagonally.

FIG. 3is a perspective view illustrating an example of a support member6and filter section5according to the present embodiment. The filter section5includes the filter5F composed of filter paper and packing5P composed of elastic material, such as urethane foam and rubber material. The filter5F is formed by alternately folding the filter paper a plurality of times and includes a plurality of bent portions5C. The ridges of the bent portions5C are orthogonal to the longitudinal direction of the support member6. The packing5P is disposed on sides of the bent portions5C of the filter5F. The positional relationship between the filter section5and the support member6is determined so that the ridges of the bent portions5C are orthogonal to the longitudinal direction of the support member6, resulting in effective suppression of warping of the filter section5.

Next, an example of operation of the air conditioning device for a vehicle1according to the present embodiment will be described. When the motor10is activated to rotate the fan9, air flows into the inside/outside air switching box3through the gas inlet7. The air flowing in passes through the filter section5and then flows into the housing2through the opening2M.

The gas inlet7is located above the opening2M. The air from the gas inlet7flows in the −Z direction and into the opening2M. Part of air taken in from the gas inlet7and passing through the filter section5collides with the support member6diagonally.

FIG. 4is an enlarged cross-sectional view of the support member6according to the present embodiment. The rib portion61includes a first side surface61A facing in the −X direction and a second side surface61B facing in the +X direction. The sticking-out portion62includes an upper surface62A facing in the +Z direction and a lower surface62B facing in the −Z direction. The first side surface61A and the second side surface61B are substantially parallel to each other, and the upper surface62A and the lower surface62B are substantially parallel to each other.

The air diagonally collides with the rib portion61having a cross section longer in the Z-axis direction. In a case where air is taken in from the outside air inlet7A, the air collides with the rib portion61from the −X side. In a case where air is taken in from the inside air inlet7B, the air collides with the rib portion61from the +X side.FIG. 4schematically illustrates the flow of air taken in from the outside air inlet7A with the damper8closing the inside air inlet7B.

The air from the outside air inlet7A collides with the first side surface61A, then flows along the upper surface62A, turns at a leading end62T of the sticking-out portion62on the −X side, and flows into a space where the lower surface62B faces. An angle θ formed between the upper surface62A and the lower surface62B is approximately 360°, and the air colliding with the first side surface61A generates a swirl on the lower surface62B side.

Air not colliding with the first side surface61A turns at a leading end62T of the sticking-out portion62on the +X side of the rib portion61and flows into the space where the lower surface62B faces. The air not colliding with the first side surface61A also generates a swirl on the lower surface62B side.

That is, by providing the sticking-out portion62, swirls are generated on the lower surface62B side of the sticking-out portion62, resulting in a disturbed air flow. The disturbed air flow suppresses generation of a stagnation portion in which the flow rate decreases. This operation prevents an unbalanced flow rate or pressure of air flowing into the blower4through the opening2M and enables air having a uniform flow rate or pressure to flow into the blower4.

In a case where air having an unbalanced (non-uniform) flow rate or pressure flows into the blower4through the opening2M, it is assumed that NZ sound is amplified, causing significant noise. NZ sound refers to narrow-band noise generated in correlation with the rotational speed (N) of the blower4and the number (Z) of fans and is generated when a flow into the blower4causes periodic pressure fluctuation. It is considered that NZ sound is generated by air with an unbalanced flow rate or pressure flowing into the blower4. The inventors have found that in a case where the sticking-out portion62is provided to disturb the flow of air flowing into the blower4, generation of noise, such as NZ sound, can be reduced.

FIG. 5illustrates a support member6J according to Comparative Example. The support member6J has a cross-sectional shape extending in the Z-axis direction and is not provided with a sticking-out portion. The support member6J includes a first side surface6JA facing in the −X direction and a second side surface6JB facing in the +X direction.

Air from the outside air inlet7A collides with the first side surface6JA, then flows along the first side surface6JA, and reaches the lower end of the support member6J. Air not colliding with the first side surface6JA flows without colliding with the second side surface6JB. As illustrated inFIG. 5, this operation generates a stagnation portion YB in which the flow rate of air is slow. In a case where the stagnation portion YB is generated, it is assumed that air having an unbalanced (non-uniform) flow rate or pressure flows into the blower4through the opening2M, and NZ sound is amplified, causing unpleasant noise to be generated.

The inventors have obtained an experimental result in which use of the support member6according to the present embodiment can effectively reduce noise generation in comparison with the case using the support member6J according to Comparative Example illustrated inFIG. 5.

As described above, according to the present embodiment, even in the case where air flowing around the support member6flows into the blower4after the blower4is activated, the support member6including the sticking-out portion62can reduce amplification of NZ sound and reduce generation of unpleasant noise. Furthermore, the rib portion61provided enhances rigidity of the support member6extending in the longitudinal direction. Thus, even in the case where force of air flowing from the gas inlet7through the filter section5into the opening2M causes the filter section5to warp, the support member6can effectively suppress warping of the filter section5.

In the present embodiment, the support member6is provided across the opening2M to effectively suppress warping of the filter section5. Even in the case where force of gas flowing toward the opening2M causes the filter section5to warp, the support member6located at least partially at the opening2M can effectively suppress the warping of the filter section5. In the present embodiment, the support member6is provided across the opening2M. Thus, even in a case where air collides with the support member6directly, the improved structure of the support member6can suppress warping of the filter section5and reduce noise generation.

In the present embodiment, the support member6is located at least partially at the center of the opening2M. The filter section5warps in the greatest amount in the vicinity of the center of the opening2M. Thus, the support member6located at the center of the opening2M effectively suppresses warping of the filter section5.

A vehicle is typically provided with the outside air inlet7A taking in outside air and the inside air inlet7B taking in inside air, and the damper8rotating about the rotation axis BX and switching intake of the outside air and intake of the inside air. The gas inlet7(outside air inlet7A and inside air inlet7B) is often disposed away from the rotation axis BX of the damper8in the X-axis direction, so that air flowing from the gas inlet7toward the opening2M collides with the support member6diagonally. The inventors have found that in consideration of such positional relationship between the gas inlet7and the support member6, providing the sticking-out portion62in support member6can effectively reduce noise generation.

The inventors have also found that with the support member6provided so that the longitudinal direction of the support member6is parallel to the Y axis (rotation axis BX), the sticking-out portion62sticking out from the rib portion61in the X-axis direction can effectively reduce noise generation.

Since the sticking-out portion62sticks out from the rib portion61toward both sides in the transverse direction, noise generation can be reduced more effectively.

Second Embodiment

A second embodiment of the present invention will be described below. In the following descriptions, the same reference signs will be assigned to the same or substantially the same constituent elements as in the above-described embodiment, and descriptions thereof will be simplified or omitted.

FIG. 6is a cross-sectional view illustrating an example of a support member6B according to the present embodiment. A sticking-out portion62sticks out from the lower end of the rib portion61in the +X direction but not in the −X direction.

With the support member6B according to the present embodiment also, air colliding with the support member6B flows into the blower4in a disturbed manner, resulting in reduction in noise generation.

Third Embodiment

A third embodiment of the present invention will be described below.FIG. 7is a cross-sectional view illustrating an example of a support member6C according to the present embodiment. A sticking-out portion62sticks out from the central portion in the Z-axis direction of the rib portion61in the X-axis direction. In the example illustrated inFIG. 7, the sticking-out portion62sticks out from the central portion of the rib portion61toward both sides in the transverse direction.

With the support member6C according to the present embodiment also, air colliding with the support member6C flows into the blower4in a disturbed manner, resulting in reduction in noise generation.

Fourth Embodiment

A fourth embodiment of the present invention will be described below.FIG. 8is a cross-sectional view illustrating an example of a support member6D according to the present embodiment. A sticking-out portion62sticks out from the upper end of the rib portion61in the X-axis direction. In the example illustrated inFIG. 8, the sticking-out portion62sticks out from the upper end of the rib portion61toward both sides in the transverse direction.

With the support member6D according to the present embodiment also, air colliding with the support member6D flows into the blower4in a disturbed manner, resulting in reduction in noise generation.

Fifth Embodiment

A fifth embodiment of the present invention will be described below.FIG. 9is a cross-sectional view illustrating an example of a support member6E according to the present embodiment. In the present embodiment, the support member6E has a cross section orthogonal to the longitudinal direction (Y-axis direction) having a triangular shape. The support member6E includes upper surfaces62A that face the filter section5side and with which air collides and a lower surface62B that faces in the direction of the blower4(−Z direction). The angle θ formed between each of the upper surfaces62A and the lower surface62B is, for example, 300°. That is, a corner, defined by the upper surface62A and the lower surface62B, of the support member6E is pointed (acute).

In this way, the angle θ formed between the upper surface62A and the lower surface62B may be smaller than 360°. Note that the angle θ is preferably greater than 270° to effectively reduce noise generation by air colliding with the support member6E, causing the flow of air to be disturbed.

Sixth Embodiment

A sixth embodiment of the present invention will be described below.FIG. 10is a partial perspective view illustrating a support member6F according to the present embodiment.

In the present embodiment, a sticking-out portion62includes first portions71of which a sticking-out amount from the rib portion61is a first dimension F1and second portions72of which a sticking-out amount is a second dimension F2different from the first dimension F1. The first portions71and the second portion72are disposed alternately in the longitudinal direction (Y-axis direction). In the example illustrated inFIG. 10, the first dimension F1is greater than the second dimension F2. The first portions71and the second portions72disposed alternately in the longitudinal direction provide recesses and projections at the leading ends of the sticking-out portion62in the transverse direction (X-axis direction). The recesses and projections have regular intervals. Note that intervals of the recesses and projections refer to distances between adjacent projections or distances between adjacent recesses in the longitudinal direction.

In the example illustrated inFIG. 10, the projections in the recesses and projections have pointed leading ends.

The inventors have found that the recesses and projections provided at the leading ends of the sticking-out portion62can reduce noise generation more effectively. It is assumed that noise generation can be reduced because the recesses and projections provided at the leading ends of the sticking-out portion62further disturb the flow of gas.

Note that the projections in the recesses and projections may have rounded leading ends, like a support member6G illustrated inFIG. 11.

Seventh Embodiment

A seventh embodiment of the present invention will be described below.FIG. 12is a partial perspective view illustrating a support member6H according to the present embodiment.

In the present embodiment, a sticking-out portion62includes third portions73of which a dimension in the Z-axis direction is a third dimension H3and fourth portions74of which a dimension is a fourth dimension H4different from the third dimension H3. The third portions73and the fourth portions74are disposed alternately in the longitudinal direction (Y-axis direction). In the example illustrated inFIG. 12, the third dimension H3is greater than the fourth dimension H4. The third portions73and the fourth portions74disposed alternately in the longitudinal direction provide recesses and projections on the upper surface of the sticking- out portion62. The recesses and projections have regular intervals.

The inventors have found that the recesses and projections provided on the upper surface of the sticking-out portion62can also effectively reduce noise generation. It is also assumed that noise generation can be reduced because the recesses and projections provided on the upper surface of the sticking-out portion62further disturb the flow of gas.

Note that the recesses and projections may be provided on the lower surface, facing the blower4, of the support member6H.

Eighth Embodiment

An eighth embodiment of the present invention will be described below.FIG. 13is a top view of a housing2according to the present embodiment.

As described with reference toFIG. 2and the like, in each of the above-described embodiments, the longitudinal direction of the support member6is parallel to the rotation axis BX (Y axis). As illustrated inFIG. 13, the longitudinal direction of the support member6may be inclined relative to the rotation axis BX in the XY plane. Note that an angle α formed between the longitudinal direction of the support member6and the rotation axis BX in the XY plane is preferably 45° or smaller and more preferably 30° or smaller.

Even in a case where the longitudinal direction of the support member6is not parallel to the rotation axis BX (Y axis), and in a case where air taken in from the gas inlet7flows around the support member6into the blower4, noise generation can be reduced with an angle α of 45° or smaller.

REFERENCE SIGNS LIST