JPH0796953B2 - Air conditioner - Google Patents

Description

TECHNICAL FIELD The present invention relates to an air conditioner.

2. Description of the Related Art Conventionally, in an air conditioner having a cross flow fan, various measures have been taken to prevent surging.

An example of the above-described conventional air conditioner will be described below with reference to the drawings.

FIG. 4 shows the structure of a ventilation circuit of an air conditioner having a conventional cross flow fan. As shown in the figure, the suction side has a suction grill 5, a heat exchanger 6 and the like, and a cross flow fan 1, a casing front plate 2, a casing rear plate 3 and the like constitute a ventilation circuit. Also, cross flow fan 1
As shown in FIG. 5, an appropriate number of fan blocks 10 are connected to form a long fan rotor.

However, in the configuration of FIG. 5 described above, since the fan rotor of the cross flow fan 1 is long, various devices (for example, the heat exchanger 6) arranged upstream of the fan air intake port.
Etc.) or the shape of the casing (for example, the casing front plate 2 and the casing rear plate 3) of the air flow passage, the air resistance distribution on the fan suction side becomes non-uniform along the entire length of the cross flow fan 1, and the cross flow fan 1 At the time of rotation, the air volume from the part with a large intake air resistance is smaller than the air volume from the part with a small air resistance, and if a small-scale air volume imbalance occurs at first, the air from the large air volume then flows from the part with a small air volume. The wind is attracted, and the difference in the amount of airflow increases.

By the way, the air volume of a certain part is
It is empirically known that when the temperature becomes equal to or lower than the point P on the characteristic curve in the figure, the portion is operated in a so-called unstable region, a surging phenomenon occurs, and the entire crossflow fan emits vibration and noise.

The "unstable region" here means P on the characteristic curve of FIG.
It is a region where the static pressure decreases as the air volume decreases, such as the part on the left side of the point.

Here, if the air volume decreases, the static pressure decreases, and the force acts on the fan in the direction in which the air volume decreases. Therefore, the force acts in the direction that promotes the fluctuation of the air volume. Therefore, once the air volume fluctuates in this region, it is not stable. Further, the “stable region” in FIG. 6 is a region on the right side of the point P on the characteristic curve, where the static pressure decreases as the air volume increases, and the static pressure increases as the air volume decreases, The fan balances the load at a single point having an arbitrary static pressure and air volume depending on the load state to perform stable operation.

In addition, generally, at both ends of the cross-flow fan, the static pressure is small because the air volume is small, and the imbalance of the air volume is likely to occur, which may cause surging when the appropriate air resistance increases due to clogging of the filter. It was

The present invention has been made in view of the above problems, and an object thereof is to prevent surging of an air conditioner.

Means for Solving the Problems In order to solve the above problems, the present invention configures a ventilation circuit from a crossflow fan, a casing front plate, and a casing rear plate, and a part of the outlet side of the casing rear plate has a high height. Well,
A plurality of ribs having a uniform width and a uniform mounting pitch are formed in a direction perpendicular to the cross flow fan.

Further, ribs are provided especially at both ends.

Effect The present invention has the above-described configuration, and even if there is a non-uniform distribution of suction resistance on the upstream side of the suction port of the cross flow fan, static pressure increases due to the ribs provided on the casing rear plate,
No drift is generated in the axial direction of the long fan rotor.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 to 3 of the accompanying drawings.

FIG. 1 is an internal cross-sectional view of an indoor unit of a separate type air conditioner.

As shown in the figure, there are a suction grill 5, a heat exchanger 6, etc. on the suction side, and the crossflow fan 1, the casing front plate 2 and the casing rear plate 3 form a ventilation circuit.
The rib 4 of the present invention is formed on the blow-out side inner surface of the casing rear plate 3. Further, a vertical deflection blade 7 and a horizontal deflection blade 8 are attached to the outlet side.

FIG. 2 is an enlarged perspective view of the air outlet portion of FIG. As shown in the figure, ribs 4 are formed on the blow-out side inner surface of the casing rear plate 3 (in this figure, the ribs 4 are attached to both blow-out side end portions with low suction air resistance).

FIG. 3 is an enlarged view of the AA cross section of FIG. As shown in the figure, the rib 4 has a height h above the inner surface of the casing rear plate 3,
The width is t and the length is l, and the ribs are integrally formed at equal pitch intervals p.

According to this configuration, when there is no rib 4, when the ventilation resistance on the suction side of the crossflow fan 1 increases due to the clogging of the filter, etc., the current flows unevenly from the center of the crossflow fan 1 toward both ends where the suction air resistance is low. W (indicated by arrow)
However, since the rib 4 is provided, the ventilation area of the air blowing passage 9 is provided at a position downstream of the area (both ends) having a small air resistance. It will be narrowed down, preventing the occurrence of drift W from the one with a large suction air resistance to the one with a small suction air resistance,
As a result, the occurrence of the surging phenomenon can be prevented.

Further, when surging occurs in the related art, a square polyethylene or the like is attached as a countermeasure, whereas the rib 4 is integrally formed with the casing rear plate 3, so that the cost and the number of steps for attaching the polyethylene can be reduced. Further, when the width t of the rib 4 is wide, the sink mark is generated at the time of molding. However, since the width t of the rib 4 is set to the maximum dimension that does not cause the sink mark, there is no fear of that.

Effects of the Invention As described above, the air conditioner of the present invention prevents uneven flow in the axial direction of the fan, thereby preventing the occurrence of the surging phenomenon, and of a quiet and stable air conditioner without noise or vibration. Enables driving.

[Brief description of drawings]

FIG. 1 is an internal cross-sectional view of an indoor unit of a separate type air conditioner according to an embodiment of the present invention, FIG. 2 is an enlarged perspective view of an air outlet portion of the indoor unit, and FIG. 3 is an AA of the air outlet portion. A line sectional view, FIG. 4 is an internal sectional view of a conventional indoor unit, FIG. 5 is a plan view of a crossflow fan, and FIG. 6 is a characteristic diagram of the crossflow fan. 1 ... Cross flow fan, 2 ... Casing front plate, 3
...... Casing back plate, 4 ... ribs, 5 ... heat exchanger.

Claims (2)

[Claims] 1. A cross-flow fan, a casing front plate, and a casing rear plate constitute a ventilation circuit, and a plurality of ribs having a uniform height, width, and mounting pitch are formed on a part of the outlet side of the casing rear plate. An air conditioner formed in a direction perpendicular to the cross flow fan. 2. A crossflow fan, a casing front plate, and a casing rear plate constitute a ventilation circuit, and a casing rear plate constitutes a ventilation circuit, and a height is provided at both ends of the casing rear plate on the outlet side. An air conditioner in which a plurality of ribs having a uniform width and mounting pitch are formed in a direction perpendicular to the cross flow fan.