Blower

The present application is a continuation application of International Patent Application No. PCT/JP2024/003378 filed on Feb. 2, 2024, which designated the U.S. and claims the benefit of priority from Japanese Patent Application No. 2023-017709, filed on Feb. 8, 2023. The entire disclosures of all of the above applications are incorporated herein by reference.

The present disclosure relates to a blower.

A blower includes a casing having an intake hole that opens to one side in an axial direction, and a centrifugal fan disposed within the casing and having multiple blades arranged in a circumferential direction about an axis.

According to at least one embodiment, a blower includes a casing having an intake hole which opens on one side in an axial direction. The axial direction is defined by an axis extending along a length of the casing. Within the casing, a centrifugal fan is housed. The centrifugal fan has blades arranged circumferentially about the axis. Each pair of adjacent blades defines an air flow path between them. The blades rotate in one direction about the axis, drawing air from one side through the intake hole into the air flow path, and discharge it outward in a radial direction with respect to the axis. Additionally, at least one guide may be included, having a guide surface which directs air into the air flow path. This causes the air to swirl in the rotational direction while being drawn into the air flow path of the centrifugal fan. The at least one guide is configured such that a main stream of air flowing from the one side to another side in the axial direction and drawn into the air flow path is directed toward a direction of a main stream of air flowing through the air flow path.

To begin with, examples of relevant techniques will be described.

A blower according to a comparative example include a casing having an intake hole that opens to one side in an axial direction, and a centrifugal fan disposed within the casing and having multiple blades arranged in a circumferential direction around an axis. As the centrifugal fan rotates about the axis, the centrifugal fan draws air into the casing through the intake hole on one axial side, pulling the air between adjacent blades among the multiple blades. The fan then expels this drawn-in air radially outward while rotating the centrifugal fan around the axis.

In the blower of the comparative example, as the centrifugal fan rotates, the centrifugal fan draws air into the casing through the intake hole on one axial side, pulling the air between adjacent blades among the multiple blades, and then expels this drawn-in air radially outward.

However, as described above, a direction of the air flow drawn between adjacent blades among the multiple blades through the intake hole on one axial side, and a direction of the air flow expelled radially outward between adjacent blades among the multiple blades, differ significantly.

Therefore, according to inventor's study, as described above, when air passes through the intake hole from one axial side and flows between adjacent blades among the multiple blades, turbulence occurs in the airflow, which may cause noise generation.

In contrast to the comparative example, according to a blower of the present disclosure, noise generation can be reduced.

According to one aspect of the present disclosure, a blower includes a casing having an intake hole which opens on one side in an axial direction. The axial direction is defined by an axis extending along a length of the casing. Within the casing, a centrifugal fan is housed. The centrifugal fan has blades arranged circumferentially about the axis. Each pair of adjacent blades defines an air flow path between them. The blades rotate in one direction about the axis, drawing air from one side through the intake hole into the air flow path, and discharge it outward in a radial direction with respect to the axis. Additionally, at least one guide is included, having a guide surface which directs air into the air flow path. This causes the air to swirl in the rotational direction while being drawn into the air flow path of the centrifugal fan. The at least one guide is configured such that a main stream of air flowing from the one side to another side in the axial direction and drawn into the air flow path is directed toward a direction of a main stream of air flowing through the air flow path.

According to this configuration, by providing one or more guides, the main direction of the airflow being drawn into the air flow path can be aligned with the main direction of the airflow passing through the air flow path.

As a result, the air guided by the at least one guide is smoothly drawn into the air flow path. As a result, abnormal noise that occurred when air was drawn into the air flow path can be reduced.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals as each other, and explanations will be provided to the same reference numerals for simplifying descriptions.

andshow an inside air conditioning unitof a vehicle air-conditioning device according to a first embodiment. The inside air conditioning unitof the present embodiment is installed inside a vehicle compartment, where the inside air conditioning unit intakes air from either inside or outside the vehicle compartment, adjusts a temperature of an intake air, and then discharges the adjusted air into the vehicle compartment.

More specifically, as shown inand, the inside air conditioning unitof the present embodiment includes an air guide casingA, a scroll casingB, a filter, a heat exchanger, a multi-blade fan, and pre-swirl guides.

is a cross-sectional view of the air guide casingA cut along a plane orthogonal to an axis S, andis a cross-sectional view taken along line II-II in. In, the axis S is a rotational centerline of the multi-blade fan, and am axial direction Za is a direction in which the axis S extends.

The air guide casingA is formed, for example, from a resin material or a metallic material, and defines an air flow paththat allows air to flow from one side to the other in the axial direction Za. The air flow pathis an air passage that guides an interior air of the vehicle compartment or an exterior air of the vehicle to an intake holeof the scroll casingB.

The filteris positioned within the air guide casingA and filters air flowing through the air flow path.

The heat exchangeris a cooling heat exchanger positioned within the air guide casingA, which cools the air in the air flow pathby exchanging heat between the air that has passed through the filterand refrigerant.

Additionally, the heat exchangermay also be a heating heat exchanger that heats the air by exchanging heat between the air in the air flow paththat has passed through the filterand the refrigerant. The heat exchangermay utilize both a cooling heat exchanger and a heating heat exchanger.

The scroll casingB is positioned on the other side in the axial direction Za relative to the air guide casingA. The scroll casingB is formed, for example, from a resin material or a metal material. The scroll casingB houses a multi-blade fan.

The scroll casingB includes a ceilingthat is formed to cover the multi-blade fanfrom one side in the axial direction Za. The ceilinghas the intake holethat is open on one side in the axial direction Za.

The intake holeis a ventilation passage that guides the airflow from the air flow pathof the air guide casingA to the multi-blade fanwithin the scroll casingB. The intake holeof the present embodiment is formed in a circular shape centered around the axis S. An intake-hole forming portionof the ceiling, which constitutes the intake hole, forms a bell mouth.

As shown in, the bell mouth is formed in an arc shape that is convex on one side in the axial direction Za when viewed in a cross-sectional view cut along a virtual plane containing the axis S. The bell mouth is provided around the entire circumference centered on the axis S.

The bell mouth plays a role in smoothly guiding air in the air flow pathof the air guide casingA from the outside in a radial direction Ka with respect to the axis S (i.e., a radially outer side) to the other side in the axial direction Za.

The scroll casingB has a blowing portfor discharging air blown out from the multi-blade fan.

The multi-blade fanconstitutes a centrifugal fan that, by rotating on one side of the radial direction Ra around the axis S, blows air outward in the radial direction Ka with respect to the axis S, which has flowed in from one side in the axial direction Za through the intake hole

As shown in, the multi-blade fanof the present embodiment is a turbo fan that includes blades, a main plate, and a ring.

The bladesare arranged at equal intervals in a circumferential direction centered around the axis S. Each of the bladesis formed such that, from an outer side to an inner side in the radial direction Ka centered around the axis S, they advance on one side in the radial direction Ra.

Between each pair of adjacent bladesamong the blades, an air flow pathis provided. This air flow pathblows the air, which flows in through the intake holeof the scroll casingB, outward in the radial direction Ka with respect to the axis S by centrifugal force.

The main plateis positioned on the other side in the axial direction Za relative to the blades. The main plateis formed in a disk shape centered around the axis S. The main platesupports the bladesfrom the other side in the axial direction Za.

The ringis positioned on one side in the axial direction Za relative to the blades. The ringis formed in a ring shape centered around the axis S. The ringsupports the bladesfrom one side in the axial direction Za.

The blades, the main plate, and the ringare formed from, for example, a resin material or a metal material. The multi-blade fanof the present embodiment is configured to be driven by an electric motor (not shown) so that it can rotate in one direction Ra of rotation around the axis S.

Each of the pre-swirl guidesguides the air drawn into the air flow pathof the multi-blade fan, so that the air is drawn into the air flow pathof the multi-blade fanwhile swirling in one direction Ra of rotation.

An outer region in the radial direction Ka around the respective axes S of the pre-swirl guidesis positioned on one side in the axial direction Za relative to the ceilingof the scroll casingB. That is, the outer region of the pre-swirl guidesis positioned outside the intake holeof the scroll casingB.

An inner region in the radial direction Ka around the respective axes S of the pre-swirl guidesis positioned radially inward (i.e., in the radial inward direction) relative to the intake holeof the scroll casingB.

The pre-swirl guidesare arranged in the circumferential direction around the axes S, respectively. More specifically, the pre-swirl guidesare arranged at equal intervals in the circumferential direction around the axes S. The pre-swirl guidesare each formed to extend from an outer side to an inner side in the radial direction Ka around the axes S relative to the intake hole

The pre-swirl guidesare each formed to protrude from the ceilingand the intake-hole forming portion. The pre-swirl guidesare each supported by the ceilingand the intake-hole forming portion.

The pre-swirl guidesare each formed to extend on the other side Rb in a rotational direction as they move from the inner side to the outer side in the radial direction Ka around the axes S, respectively. The other side Rb in the rotational direction is an opposite side Ra of the rotational direction shown in.

The pre-swirl guideseach include lateral surfacesand. The lateral surfaceis a first guide surface formed on the one side Ra in the rotational direction of each of the pre-swirl guides.

The lateral surfaceis a second guide surface formed on the other side Rb in the rotational direction of each of the pre-swirl guides. The lateral surfaces,are each formed to extend on the other side Rb in a rotational direction as they move from the inner side to the outer side in the radial direction Ka around the axes S, respectively.

The pre-swirl guidesare each formed in a thin plate shape with a distance between the lateral surfacesandas the thickness. Inter-guide flow pathsare provided between each pair of adjacent pre-swirl guidesamong the pre-swirl guides.

The lateral surfacesandof each of the pre-swirl guidesare guide surfaces that direct the air flowing through the inter-guide flow paths, so that the air passing through the intake holeis drawn into the air flow pathsof the multi-blade fanwhile swirling in the one side Ra in the rotational direction.

Hereinafter, for the sake of convenience in explanation, in each of the pre-swirl guides, a region positioned radially inward Ka around the axis S with respect to the intake-hole forming portionis referred to as inner guide regionsA.

Here, as shown in, the other endin the axial direction Za of each of the inner guide regionsA is provided at the same position in the axial direction Za as the other endin the axial direction Za of the intake-hole forming portion.

The other endin the axial direction Za of each of the inner guide regionsA is positioned on one side Za in the axial direction with respect to a ceiling surfaceof the ceilingof the scroll casingB, which is located on the other side Za in the axial direction.

The other end (forming portion end)of the intake-hole forming portionis formed so as to surround the intake hole end (intake-hole end), which is positioned furthest on the other side Za in the axial direction (i.e., the furthest on the other side in the axial direction) of the intake hole. Each of the pre-swirl guidesof the present embodiment is made of, for example, a resin material or a metal material.

More specifically, each of the pre-swirl guidesconstitutes an integral component that is integrated with the scroll casingB. Each of the pre-swirl guidesis configured as a separate component from the scroll casingB. In the present embodiment, the scroll casingB, the multi-blade fan, and the pre-swirl guidesin the inside air conditioning unitconstitute a blower.

Next, the operation of the inside air conditioning unitof the present embodiment will be described.