JPS6131384B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an air conditioner or the like equipped with vertical deflection blades capable of deflecting blown air in the vertical direction.
This invention relates to a wind blowing direction changing device that provides excellent feeling and achieves quiet operation.

Conventionally, for the purpose of improving the feeling, left and right deflection vanes or vertical deflection vanes are provided at the outlet of an air conditioner, and these deflection vanes are driven by a synchronous motor, a stepping motor, or the like. In particular, vertical deflection blades have great effects such as uniform room temperature distribution and cooling sensation. However, the above-mentioned vertical deflection blades are usually driven by a stepping motor in many cases, and noise during driving becomes a problem. The present invention aims to effectively reduce this noise level.

A wind blowing direction changing device according to an embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

In the figure, 1 is the outer box of the air conditioner main body. 2 is a heat exchanger, and after the indoor air sucked in from the intake port of the outer box 1 exchanges heat with this heat exchanger 2, it is transferred to a wind cylinder 3, a cross flow fan 4, a vertical deflection blade 5, and a left and right deflection blade 6. It is blown out through.

FIG. 2 shows how the upper and lower deflection blades 5 are attached. One shaft at the end of the vertical deflection blade 5 is supported by a bearing 6 fixed to the air conditioner body, and the other shaft is supported by a stepping motor 8 with a built-in gear for deceleration by an elastic force coupling 7. Fixed to the output shaft. A position detector 9 is provided at one end of the vertical deflection blade 5 and detects the rotational position of the vertical deflection blade 5. A frequency changing device 10 changes the driving frequency of the stepping motor 8 in response to a signal from the position detector 9.

Now, suppose that the stepping motor 8 is swung by a certain angle at a certain speed in order to continuously change the direction of the blowing air in the vertical direction. Then, the blown air is continuously deflected by the upper and lower deflection blades 5. At this time, stepping motor 8
Due to the characteristics of the motor, it rotates in steps, which generates noise. In order to suppress the noise, it is possible to improve the characteristics of the stepping motor 8, that is, to reduce the stepping angle and improve gear accuracy, but this becomes a factor in increasing costs. Further, reducing the elasticity of the elastic coupling 7 has a noise prevention effect, but has the disadvantage that the vertical deflection blades 5 no longer follow the stepping motor 8. Therefore, the present invention aims to reduce noise by focusing on the fact that noise changes depending on the driving frequency and load torque of the stepping motor 8. This point will be discussed in detail next.

FIG. 3 shows the noise level when the stepping motor 8 is driven at a constant swing angle and constant speed. The trajectory of the cycle A→B→C→D→A is the noise level when the vertical deflection blade is driven in the order of L→U→L in FIG. Cycle A′→B′→
The trajectory C'→D'→A' shows the noise level when the driving frequency of the stepping motor 8 is increased and the speed is increased. The reason why the noise level decreases as the swing speed increases is because the rotational state of the stepping motor 8 approaches a smoother continuous rotational state from a stepwise state. If you just want to reduce noise, you can increase the drive frequency, but the optimum time for swinging the vertical deflection blades on the feeling surface is about 10 seconds, and it is not possible to uniformly increase the drive frequency.

The present invention focuses on the fact that the noise generated when driving the upper and lower deflection blades changes depending on the driving frequency of the stepping motor 8 and the angle of the upper and lower deflection blades 5, and the driving frequency is reduced at rotational positions where the noise level is high. The drive frequency is lowered at rotational positions where the noise level is low, thereby lowering the noise level and keeping the average drive frequency low to some extent over the entire swing period of the vertical deflection blades 5. The relationship between the angle of the upper and lower deflection blades 5 and the noise level depends on the shape of the upper and lower deflection blades 5, but the larger the load torque of the stepping motor 8, the higher the noise level.

Therefore, a position detector 9 detects the position where the load torque of the stepping motor 8 becomes large and a position where it becomes small, and a signal from the position detector 9 is sent to the frequency changing device 10. That is, when the position detector 9 detects a position where the load torque is large, the frequency changing device 10 receives the signal from the position detector 9 and increases the frequency of the power supplied to the stepping motor 8. Conversely, the frequency is lowered at positions where the load torque is smaller. Thereby, the vertical period of the vertical deflection blade can be maintained at a desired period, and noise can be kept low.

As is clear from the description of the embodiments above, the wind blowing direction changing device of the present invention includes a deflection blade that is provided at the wind outlet and changes the wind blowing direction by rotating; a stepping motor that rotates; and a frequency changing device that increases the frequency of power supplied to the stepping motor when the load torque becomes large, in accordance with the load torque of the stepping motor that varies depending on the position of the deflection blade. It is what it is.

Therefore, when swinging the deflection blade at a certain angle, the driving frequency of the stepping motor is increased in areas where the load torque is large, and the driving frequency of the stepping motor is increased in areas where the load torque is large, depending on the load torque determined by the rotational position of the deflection blade. By the way, by lowering the drive frequency and driving the stepping motor,
The noise level can be suppressed over the entire swing cycle, and the average drive frequency can be kept low to a certain extent, and even with an inexpensive stepping motor with a relatively large step angle, a relatively large swing cycle can be achieved. , it is possible to realize a wind blowing direction changing device with excellent feeling and low noise.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an air conditioner equipped with a wind blowing direction changing device according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of the wind blowing direction changing device, and FIG. FIG. 3 is a characteristic diagram showing the relationship between noise levels. 5... Vertical deflection blade, 8... Stepping motor, 10... Frequency change device.

Claims (1)

[Claims] 1. A deflection blade that is provided at the wind outlet and rotates to change the wind blowing direction, a stepping motor that rotates the deflection blade, and a load on the stepping motor that varies depending on the position of the deflection blade. and a frequency changing device that increases the frequency of power supplied to the stepping motor when the load torque becomes large according to the torque.