JPS5825132A - Floor nozzle of electric cleaner - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses the same method nozzle to muffle the airflow noise generated from the 4m air blowing of the vacuum cleaner body, which propagates through the entire length of the hose and extension V to the suction port of the floor nozzle. The purpose is to reduce noise.

The main sources of noise in conventional vacuum cleaners are the exhaust noise generated from the vacuum cleaner itself, which has a built-in electric blower, and the wind noise from the floor nozzle suction port, but various noise countermeasures have been taken to address these issues. , currently 52-60,1/(I I
According to SC-91089-15), the noise level is low at the foot of the mountain. However, in today's world where noise pollution has become a major social problem, even quieter vacuum cleaners are required, and noise countermeasures are needed. As mentioned above,
5L of main body exhaust noise and wind noise of the inlet at the floor nozzle
As for IT countermeasures, we have taken measures to reduce the noise value to a considerable limit, but in order to further increase the noise level by 1, we decided to reduce only the main body exhaust noise and the wind noise from the floor nozzle suction port. It has become difficult to push forward with noise countermeasures. Therefore, in order to further promote noise reduction measures, it was necessary to find another noise source and take countermeasures against that noise source, and the following noise sources were discovered. .

Traditionally, a hose is attached to the intake port of the main body of a vacuum cleaner.

The extension pipe and the floor nozzle were connected in this order, and the cross-sectional area of these pipes did not change much along the way, and they had a simple straight pipe section and a partially curved pipe section. For this reason, the airflow noise generated by the electric blower inside the vacuum cleaner body was propagated through the hose and extension pipe to the suction port of the floor nozzle, which was a source of noise.

The present invention relates to a structure for muffling this single-pitch sound source in a floor nozzle, and one embodiment of the present invention will be described below with reference to the accompanying drawings.

In the figure, 1 is a vacuum cleaner body with a built-in electric blower 2;
Reference numeral 3 denotes a dust collecting box that is detachably connected to the main body, and has an air intake port 4 on the front side. A flexible hose 5 is provided at the intake port 4.
is removably connected to the hose 6, and a tip vibro, which is used as a grip when using a vacuum cleaner, is attached to the tip of the hose 6, and a two-piece extension tube 7 is fitted and connected to the tip of the tip vibro. A floor nozzle 8 is connected to the tip of the extension tube 7.

In FIG. 2, the floor nozzle 8 is composed of an upper floor nozzle 9 and a lower urine nozzle 1o. 11 is an extension tube 7 at the other end
12 is a floor nozzle protection bumper made of a soft material such as natural rubber. Numerals 13 and 14 are N rollers and brushes, respectively, to maintain a gap between the lower part 1o of the floor nozzle and the floor surface.

Reference numeral 16 denotes a suction port provided on the lower surface of the lower nozzle portion 10, and a suction passage 1 is provided between the suction port 16 and the floor nozzle pipe 11.
5a is formed. Reference numeral 18 denotes a cavity that is in direct contact with the suction passage 15a, and is formed between the suction passage 15a and the outer wall of the nozzle. 17 is the cavity 16 and the suction passage 15a
This is a communication hole that communicates with the

Conventionally, the exhaust sound of the vacuum cleaner body 1, the suction port 1 of the floor nozzle 8,
Even in the case of a vacuum cleaner that takes measures to prevent wind noise as described in item 5, the airflow noise of the electric blower 2 is transmitted through the air intake port 4 of the collection box 3, the flexible hose 6, the extension pipe 7. It passes through the floor nozzle 8 in order and exits through its suction port 15. The generation of noise due to turbulence and eddies caused by air passing through the main body 1 can be relatively easily suppressed by the shape of the air passages in the main body 9, the length of the passages, sound absorbing materials on the four sides, sound insulating materials, etc. Regarding the exhaust noise directly emitted from the electric blower 2, due to the suction performance of the vacuum cleaner, it is not recommended to completely cover the area around the electric blower 2 for sound insulation or to cover it with an unnecessarily thick breathable sound-absorbing material. It is possible. For this reason, noise was coming out from the opening at the front of the main unit, ie, the floor nozzle suction port, where no noise prevention measures had been taken in the past. Above all, the high-frequency sound is a harsh noise.Among the exhaust noises generated by the dynamic air blower 2, the particularly loud noise is caused by the rotation of the fan of the electric blower 2, which exerts a periodic force on the air.・Rotation of rn d) An airflow sound with a frequency of n expressed by X (number of blades of the fan) is generated. In this embodiment, the number of rotations is 360 times/second and the number of blades is 7, so the number of blades is around 2.5.

This 2.5 k) h is generated in a rotating machine such as a fan to a greater or lesser degree.Furthermore, this acoustic energy is proportional to the rotation speed, and in a rotating machine such as a vacuum cleaner that rotates at high speed. Fans that are forced to do so tend to make a lot of noise.

The present invention aims to muffle the sound just before such a specific frequency reaches the floor nozzle suction pipe 11.
A cavity is formed between the outside of the nozzle and the outer wall of the floor nozzle. The present invention has the advantage of configuring a resonance type muffler in this cavity, so that the 2.5 kHz is muffled just before it goes out into the outside air, and the noise is reduced without the need for a complicated muffler or sound absorbing material. It is something to do.

Note that the insertion loss of this cavity is calculated using the following formula.

Further, the resonance frequency is calculated using the following formula.

However, 12 Frequency C = Speed of sound ■ = Volume of cavity Soi Area of communication hole G = Approximately equal to diameter of communication hole A noise analysis diagram is shown in FIG. The vertical axis represents the sound pressure level in dB%, and the horizontal axis represents the frequency kiz. As for the noise value, the vacuum cleaners are compared in terms of A-applicability.

In the figure, the solid line indicates the characteristic value of this embodiment, and the broken line indicates the characteristic value of the conventional example.

According to this, whereas conventionally the 2.5 roar sound was particularly high, when the floor nozzle of the present invention was used, the 2.5 sound became lower, the peak value became smaller, and the noise was reduced. This is confirmed.

Note that it is also possible to shift the resonance frequency by completely filling the cavity with a sound absorbing material such as urethane foam or glass fiber.

[Brief explanation of the drawing]

Figure 1 is a side view of the various parts connected when using a vacuum cleaner.
FIG. 2 is a sectional view of a floor nozzle showing an embodiment of the present invention, and FIG. 3 is a noise ratio analysis diagram of the present invention and a conventional example. 1. Vacuum cleaner body, 5. Hose, 16.
...Suction port, 15a...Suction passage, 16
...Cavity, 17...Communication hole. Name of agent: Patent attorney Toshio Nakao and 1 other person 1 Indication of case: 1986 Patent Application No. 55036” 2. Name of invention: Floor nozzle of a vacuum cleaner 3. Relationship with the case of person who amends floor nozzle of vacuum cleaner 3. Patent application
Appointment Address: 1006 Kadoma, Kadoma City, Osaka Prefecture
(582,) Representative of Matsushita Electric Industrial Co., Ltd.
Toshihiko Yamashita 4th Agent 571 Address Matsushita Electric Industrial Co., Ltd., 1006 Kadoma, Kadoma City, Osaka Prefecture I would like to supplement Figures 1, 2, and 3 with the attached circular.

Claims (1)

[Scope of Claims] 14 is connected to the vacuum cleaner main body via a hose or the like, and has a suction passage with a suction port connected to the lower part. A floor nozzle for a vacuum cleaner in which a cavity is formed between the suction passage and the outer shell, and the cavity and the suction passage are communicated through a communication hole provided in the suction passage.