JPH02163499A - Fan controller - Google Patents

Abstract

PURPOSE:To keep off any drop in fan performance by constituting a resonance system with a boss part with an impeller and an elastic body, making this resonance system have resonance at a low revolution range out of a normal operating revolution range of a fan, and letting a control circuit drive a motor as long as the specified time at resonance revolution after a shutdown of the fan. CONSTITUTION:Air is fed to equipment including a combustor or the like out of a supply opening 11 from an inlet port 10 of a fan 4 by way of the inside of a casing 2, while dust or the like being inhaled in together with this air sticks to a part of an impeller 1 or the like. Each time output of a revolution detecting part 8 comes to zero from a revolution range at time of usual equip ment operation, a control circuit 9 works so as to operate as long as the speci fied time at revolution accorded with resonance revolution with a boss part 7 with an impeller 1 and an elastic body 6, therefore vibration is added to the impeller 1 each time the fan 4 operates, and dust or the like stuck is in no case accumulated, thus such a possibility that blasting performance might be sharply lowered is prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a control device for a blower that supplies combustion air in, for example, a combustion machine. The purpose of this is to prevent the reduction in supply air that occurs.

BACKGROUND ART As shown in FIG. 4, a conventional blower 20 of this type is composed of an impeller 21, a casing 22, and a motor 23. The impeller 21 is attached to a shaft 24 of the motor 23 via a boss 25. The motor 23 is controlled to rotate in a direction determined by the shape of the blades 26 constituting the impeller 21. As a result, air flows from the suction port 27 into the impeller 21 and into the casing 2 due to the rotation of the impeller 21 (indicated by a solid arrow).
2 and is supplied to equipment such as a combustion machine (not shown) through the suction port 28, but as shown in FIG.
Dust, etc. adheres to the vicinity of the recess of the blade 26 of No. 1, and the air blowing performance deteriorates.
As shown in FIG. 6, the supply air decreases from Qo to Qa. Therefore, if the equipment is significantly affected by the decrease in air M, a filter 29 is provided upstream of the suction port 27 to prevent dust and foreign matter from entering.

Problems to be Solved by the Invention However, with the above configuration, the load resistance increases as shown in Fig. 7 due to dust adhering to the filter itself on the blower suction side, causing the supply air to change from Qo to Qb.
decreases to i!, and the supply air decreases over time, similar to the case without a filter. There was a problem.

The present invention solves this conventional problem by forcibly rotating the impeller for a certain period of time at the resonant frequency of the blade bundle and the boss portion having an elastic body, thereby vibrating the blade itself and eliminating attached dust. The purpose is to make it fall from the feather.

Means for Solving the Problems In order to solve the above problems, the blower control device of the present invention provides a blower comprising an impeller, a casing and a motor, in which the impeller is connected to the shaft of the motor via a boss portion having an elastic body. The impeller and the boss section containing the elastic body constitute a resonant system, and the resonant system resonates in a low rotational speed range outside the normal operating speed range of the blower, and the control circuit that drives the motor is connected to the blower. After the motor stops operating, the motor is driven at the resonant rotation speed for a certain period of time.

Function The present invention uses the above-mentioned control means to drive the motor at a rotation speed that matches the resonance between the impeller and the boss portion having an elastic body for a certain period of time after the blower has stopped, so that the impeller vibrates and the impeller Dust etc. that have accumulated on the air blower are removed by vibration, which prevents deterioration in blower performance.

Embodiment Hereinafter, one embodiment of the present invention will be described based on the accompanying drawings.

FIG. 1 shows an air blower 8I34 that is composed of an impeller 1, a casing 2, and a motor 3, similar to the conventional example. The impeller 1 is attached to the shaft 5 of the motor 3 via a boss portion 7 having an elastic body 6. ing. Reference numeral 8 denotes a rotation detection section for detecting rotation, and reference numeral 9 denotes a control circuit for driving the motor 3.

In the above configuration, air flows from the suction port 10 of the blower 4 through the impeller l and the inside of the casing 2, and from the air outlet 11 to the combustor (
Dust, etc., which is supplied to the equipment such as (not shown), is sucked in with the air from the suction port 1O, and some of it adheres to the impeller 1, etc., but the operating range and rotation speed of the equipment shown in Figure 2 relationship and third
As shown in the time chart in the figure, the rotation detection unit 8
Every time the output becomes zero, the control circuit 9 operates so that the impeller 1 operates for a certain period of time T at a rotational speed (No) that matches the resonance frequency of the impeller 1 and the boss 7 having the elastic body 6, and as a result,
Vibration is applied to the impeller 1 each time the blower 4 operates, and although some of the attached dust remains without being deposited, it has the effect of preventing a large drop in blowing performance. Moreover, it goes without saying that the above-mentioned fixed time T is at a level that does not interfere with the operation sequence of the equipment.

Effects of the Invention As described above, according to the blower control device of the present invention, the following effects can be obtained.

Each time the blower starts and stops, only the impeller resonates at a low rotational speed and is forcibly vibrated to remove dust attached to the blades. In addition, within the normal operating range of the equipment, the vibration isolation of the elastic body of the boss section suppresses cogging noise caused by resonance between the motor and impeller, resulting in lower noise. It is something that can be achieved.

[Brief explanation of the drawing]

Fig. 1 is a side cross-sectional view of a blower and a control block showing an embodiment of the present invention, Fig. 2 is an explanation rgI diagram showing the relationship between the operating range and rotation speed of the equipment, and Fig. 3 is an explanation of the operation. Time chart, Figure 4 is a side cross-sectional view of a conventional blower, Figure 5 is a cross-sectional view of the blade showing the state of dust adhesion at the A-A cross section in Figure 4, and Figures 6 and 7 are load changes in the conventional example. FIG. l... Impeller, 2... Casing, 3
...Motor, 4...Blower, 5...
... shaft, 6 ... elastic body, 7 ... boss section, 9 ... control circuit. Name of agent: Patent attorney Shigetaka Awano Haka 1 person! --Feathered umbrella? ---Casing 3-m-moke operation s8 □將■ Hard and soft curved private amount

Claims (1)

[Claims] In a blower consisting of an impeller, casing, and motor,
The impeller is attached to the shaft of the motor via a boss portion having an elastic body, and the impeller and the boss portion having an elastic body constitute a resonance system, and the blower is configured to operate in a low rotation speed range outside the normal operating speed range of the blower. The blower control device is characterized in that the resonance system has resonance, and the control circuit for driving the motor drives the motor at the resonance rotation speed for a certain period of time after the blower stops operating.