JPH01164346A - Electric cleaner - Google Patents

Abstract

PURPOSE: To reduce friction resistance between a shaft and a bearing, to make action of a valve more smooth, and to improve sensitivity of a capacity detection unit, by forming a protruding body so that a part of a holding body contacts a motor fan and microvibration of the motor fan is transmitted to the bearing. CONSTITUTION: A capacity detection unit is composed of a spring 32 set between a valve 29 and a holding body 31 so as to apply force in a constant direction and an angle detection part 33 to detect an open angle of the valve 29 converted into an electric signal. The holding body 31 is set in a flow passage 24, equipped with a protrusion 36 to make a part of the holding body to be in touch with a motor fan 26, and constituted so as to transmit microvibration of the motor fan 26 to a bearing 30. Consequently, when microvibration is transmitted to the bearing 30, since the rotation resistance of the shaft becomes smaller, and even if dust invades in the bearing part, since the shaft and the bearing are not in the perfect contact condition, the rotation resistance is hard to increase to give the stable bearing performance.

Description

[Detailed description of the invention] Industrial applications This invention relates to a household vacuum cleaner.

2. Description of the Related Art A conventional vacuum cleaner will be described with reference to FIG. 3.4.5.

In the flow path 1 through which air flows, an air volume detection unit 4 is provided in the exhaust passage 3 of the motor fan 2, and a signal from the air volume detection unit 4 is transmitted to the control circuit 5 of the fan motor. The output from 4 is automatically controlled. The configuration of this air volume detection unit 4 includes a valve 5 that is rotatably held by the wind, and a holder 6 formed with a bearing 7 that serves as an external member for holding the valve 5. 9 and is rotatably attached to the valve 5 about the shaft 8, and a weight (not shown) for balancing the weight in the upper and lower positions is fixed thereto. Reference numeral 10 denotes a Hall element fixed to the holder 6, which detects the magnetic force of the magnet 9. Depending on the air volume, the valve 5 is tilted by the wind, and the distance between the magnet 9 and the Hall element IO changes, thereby changing the air volume. Detect size. Reference numeral 11 denotes a spring disposed between the valve 5 and the holding body 6 so as to apply a certain rotational force to the valve, and the force of this spring 11 is matched at a place where the force of the wind is present.

Problems to be Solved by the Invention In the conventional technology as described above, bearing friction to some extent always occurs between the shaft 8 of the valve 5 and the bearing 7 of the holder 6. As the bearing friction increases, the valve 5 becomes more difficult to move, and therefore, the sensitivity of the airflow detection unit 4 deteriorates (inability to detect slight changes in the airflow in the flow path). In Fig. 5, to explain this using symbols, F is the force that the wind from the motor fan acts on the valve 5, P is the force that the spring acts on the valve, and U is the force between the shaft and the bearing. If the static frictional resistance that occurs between
Even if the amount changes, as long as ΔF is smaller than the static frictional resistance U, F + ΔF = P + U, and the valve does not move (that is, depending on the size of ΔF, ±U changes conveniently to match). ). To eliminate this phenomenon,
It is necessary to keep ±U (static frictional resistance) as small and stable as possible.

Therefore, if the sensitivity of the air volume detection becomes low due to the conditions mentioned above, the automatic input of the motor fan cannot be adjusted appropriately. Despite this, the motor input does not increase and the phenomenon of ``not sucking up dirt'' occurs during use. A method to solve these phenomena is to increase F compared to static frictional resistance (±U).

A method of relatively increasing ΔF and P may also be considered.

This is possible by narrowing down the flow path so that all the air from the motor fan hits the airflow detection unit, but this is difficult to achieve because the pressure drop increases, efficiency decreases, and the suction power decreases.

Furthermore, if dirt or debris enters the bearing, or if it is scratched off over many years of use, the static frictional resistance will change, causing similar malfunctions in air volume detection.

Means for Solving the Problems In order to solve the above-mentioned problems, the vacuum cleaner of the present invention has a flow path through which air passes inside, and there is a part in the middle of the flow path to trap dust. A dust collection bag for collecting dust, a motor fan for generating wind pressure, and an air volume detection unit that detects the air volume and controls the input of the motor are provided, and the air volume detection unit includes a valve that opens according to the air volume. , a holder having a bearing disposed to support the shaft of the valve; a spring that applies rotational force to the valve in a certain direction between the valve and the holder; and converting the opening angle of the valve into an electrical signal. further comprising a protruding body so that a part of the holding body comes into contact with the motor fan;
The bearing is configured to transmit minute vibrations of the motor fan to the bearing.

Function: Since the present invention is configured to apply minute vibrations to the shaft and bearing, this minute vibration reduces the frictional resistance between the υ shaft and the bearing, smoothes the operation of the valve, and increases the sensitivity of the air volume detection unit. Accurate airflow detection becomes possible.

Embodiment An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a side sectional view of a vacuum cleaner showing an embodiment of the present invention, and FIG. 2 is a side sectional view showing an air volume detection unit of the same vacuum cleaner.

In FIG. 1, 21 is the main body of the vacuum cleaner, and the front part of the main body 21 has an intake port 2 through which air, dirt, etc. flow.
2 is formed in the rear part of the main body 21, and the intake port 2 is formed in the rear part of the main body 21.
An exhaust port 23 is formed for discharging air that has flowed in from the air intake port 2 , and the intake port 22 and the exhaust port 23 communicate with each other through a flow path 24 . Further, in the middle of the flow path 24, there is a dust collection bag 25 that collects only the dust that has flowed in from the air intake port 22, and a motor fan 26 that generates wind pressure to generate a flow of air in the flow path 24. and the motor fan 2
An air volume detection unit 27 is provided that detects the air volume generated by the motor fan 6 and controls the input to the motor fan.

In FIG. 2, the air volume detection unit 27 has a shaft 28
a holder 31 formed with a bearing 30 that rotatably supports the shaft 28 of the valve 29;
It is composed of a spring 32 disposed to apply a force in a fixed direction between the valve 29 and the holder 31, and an angle detection section 33 that detects the opening angle of the valve 29 by converting it into an electric signal. There is.

The angle detection section 33 includes a magnet 34 disposed at one end of the valve 29 and a Hall element 35 disposed on the holder 31. The Hall element 35 converts the change in the clearance L into a change in voltage. This change in voltage is sent to a circuit (not shown) built into the motor fan 26 to ensure that the motor fan 726 is at maximum input when the valve 29 is closed. 2
9 is fully opened, the input of the motor fan 26 is set to be low.

Further, the holder 31 is disposed within the flow path 24, and a projection 36 is further provided so that a part of the holder 31 comes into contact with the motor fan 26, so that the slight vibration of the motor fan 26 (Small vibrations □ are shown in FIG. 2) are transmitted to the bearing 3o. The bearing 3
When slight vibrations are applied to the shaft, the rotational resistance of the shaft decreases, and even if dirt or the like enters the bearing, the shaft and bearing will not be in perfect contact due to slight vibrations, so rotation will be prevented. Dynamic resistance is less likely to increase, resulting in stable bearing performance.

Effects of the Invention In the present invention, since the protrusion 36 formed on the holder 31 transmits minute vibrations of the motor fan 26 to the bearing part,
The rotational resistance of the valve 29 is reduced.

Therefore, it is possible to detect even a slight change in air volume, and the air volume detection is sufficient if there is only a small part of the flow path. Therefore, the air passing through the flow path is hardly affected by the air volume detection unit, so that pressure loss does not increase and high-performance suction force can be provided. Furthermore, due to the low bearing resistance, the valve 29 operates stably even when dirt enters, and even the slightest change in air volume is quickly detected, making automatic liquid volume adjustment extremely reliable and improving usability. Durability is improved.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view of a vacuum cleaner showing an embodiment of the present invention, Fig. 2 is a side sectional view showing an air volume detection unit of the same vacuum cleaner, and Fig. 3 is a side sectional view showing a conventional vacuum cleaner. Cross section, 4th
The figure is an exploded perspective view showing a conventional airflow detection unit, and FIG. 5 is a diagram symbolizing the force distribution of the valve. 21: Main body 24: Channel 26: Motor fan 27:
Air flow detection unit 28: Shaft 29: Valve 30: Bearing 3
1: Holding body 32 Nispring patent applicant Matsushita Electric Industrial Co., Ltd.

Claims (1)

[Claims] A flow path is formed inside through which air passes, and in the middle of the flow path, there is a dust collection bag that collects dust, a motor fan that generates wind pressure, and a motor fan that detects the air flow rate and controls the input of the motor. An air volume detection unit to control is disposed, and the air volume detection unit is arranged between a valve that opens depending on the air volume, a holder having a bearing disposed to support a shaft of the valve, and the valve and the holder. a spring that applies rotational force to the valve in a certain direction; and an angle detection section that detects the opening angle of the valve by converting it into an electric signal; The vacuum cleaner is configured to transmit minute vibrations of the motor fan to the bearing.