JPH0128766Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a vacuum cleaner that prevents an electric blower from overheating.

Generally, a vacuum cleaner has a dust collection chamber and a blower chamber inside the vacuum cleaner body, and an electric blower is placed in the blower chamber, and the fan of the electric blower rotates to collect dust. The air in the dust chamber is sucked, thereby collecting dust and dirt into the dust collection chamber through a dust collection hose, pipe, floor brush, etc. In addition, the electric blower itself is cooled by the flow of suction air,
It is designed to prevent overheating.

By the way, in such a vacuum cleaner, when the dust collection chamber is full of dust and dust, the amount of air sucked from the dust collection chamber decreases, and this also reduces the rotational resistance of the fan. As a result, the rotational speed of the electric blower itself increases significantly, but the electric blower is not cooled properly by the suction air, which may lead to overheating of the electric blower.

On the other hand, as shown in Japanese Utility Model Publication No. 52-10217, in order to automatically avoid the situation when the suction port is completely blocked, a shield plate linked to the dust collection meter is provided. At the same time, a lamp and a light-receiving element are arranged on both sides of this plate, and as the degree of vacuum inside the vacuum cleaner body increases, the amount of light irradiated by the lamp to the photoelectric element is reduced, thereby reducing the power supplied to the electric blower. A known technique is to reduce the suction force and easily remove the cleaning object from the suction port. Therefore, according to this conventional technique, even if the dust collection chamber is filled with dust, etc., it is possible to prevent the electric blower from overheating.

However, with the technology of Utility Model Publication No. 52-10217,
Focusing on changes in the degree of vacuum, the degree of vacuum is optically detected using the movement of the dust collection meter, so the detection accuracy depends on the operation accuracy of the dust collection meter, but the dust collection meter Since it is not a precision component and there are variations in the springs used, the detection accuracy is not good. Additionally, there was a problem in that if the dust collector malfunctioned, the electric blower could no longer be controlled.

Furthermore, Japanese Patent Application Laid-Open No. 57-55123 discloses that an air turbine rotated by sucked air is provided inside the vacuum cleaner body, and this rotates a generator, and the output of this generator rotates an electric motor. A technique is also known in which the number of rotations of the electric motor is decreased when the flow resistance of the intake air is reduced, and conversely, the rotation speed of the electric motor is increased when the flow resistance increases.

However, with this technology, the cleaning conditions are detected by the strength of the suction air flow and the electric motor is driven accordingly. cannot prevent overheating. Furthermore, in this technology, the air turbine and generator serving as the sensing means are not directly connected to the electric motor, so the sensing is indirect, resulting in inaccurate control. Moreover, since the air turbine and generator are placed in the wind path, the wind path resistance is large, and along with the use of the generator, a cylinder body and a cylindrical body are required to pass the intake air to the air turbine. The structure of the detection means is quite complicated, such as requiring parts to support the generator, and is therefore disadvantageous in terms of cost. Furthermore, since the generator is equipped with mechanically moving parts, there are problems such as the detection accuracy being impaired due to wear of the moving parts during use, and maintenance being troublesome. Therefore, it is not preferable to employ this detection technique as a detection means for preventing overheating of an electric blower.

Furthermore, as previously shown in Japanese Utility Model Publications No. 48-19487 and Japanese Utility Model Publication No. 48-19488, a finger speed generator is used as a detection means in order to prevent the suction power from decreasing due to the accumulation of dust. , the increase in the rotational speed of the electric blower when the suction force decreases is detected by the increase in the induced voltage of the finger speed generator directly connected to this electric motor, and the electric motor is activated to increase the suction force of the fan based on this detection. Control techniques are also known.

However, with this technology, when the dust collection chamber is full of dust, the electric blower is turned up to ensure the air volume, which means that the electric blower is operated under overload. There is a problem in that the electric blower becomes overheated. Furthermore, since a generator with a complex structure is used as the detection means,
In addition to being disadvantageous in terms of cost, there is a problem in that there is a high possibility of failure due to the mechanically operating parts of the generator. Moreover, since the rotation of the electric blower is not directly detected but indirectly detected electrically, control is inaccurate.In addition, the electric blower has extra power to drive the generator directly connected to it. Since the electric blower requires power, the load on the electric blower is large. Therefore, it is not preferable to employ such a detection technique as a detection means for preventing overheating of an electric blower.

The purpose of this invention is to detect the degree of clogging in the dust collection chamber with high precision and reliability, and to reliably prevent overheating of the electric blower. The purpose of the present invention is to provide a vacuum cleaner that does not impose a load, has a simple structure, and has excellent durability.

That is, in order to achieve the above object, the vacuum cleaner of this invention has a lamp and a light-receiving element arranged in correspondence with each other, and a lamp and a light-receiving element are provided between them on the rotating shaft of an electric blower so that they are integrally driven to rotate. A rotating member is provided, a light passing section is formed therein, and the number of rotations of the rotating member is detected based on the number of optical signals that pass through the light passing section and enter the light receiving element, and the detected number of rotations is detected. The present invention is characterized in that an energization control mechanism for controlling energization of the electric blower is provided based on the above.

An embodiment of this invention will be described below based on the drawings.

In the figure, 1 is the main body of the vacuum cleaner. This vacuum cleaner body 1
is constructed in a divided manner, consisting of a dust collection section 2 and an electric motor section 3, which are detachably connected via a clamp 4. Note that 5 is a front wheel made of casters, and 6 and 6 are rear wheels.

The dust collection section 2 has a dust collection chamber 7 formed inside thereof, and this dust collection chamber 7 is connected to a dust collection hose (not shown) through a connection port 8 in the front part. There is. Note that a floor brush or the like is connected to the tip of the dust collection hose via a dust collection pipe. Further, an opening/closing lid 9 is provided on the upper surface of the dust collecting section 2, and the opening/closing lid 9 is opened to discharge dust and dirt accumulated in the dust collecting chamber 7.

On the other hand, the inside of the electric motor section 3 is divided into a blower chamber 10, an exhaust chamber 11, and a cord reel chamber 12. An electric blower 14 is disposed in the blower chamber 10 via support members 13 made of an elastic material, and a power supply cord 15 is disposed in the cord reel chamber 12.
is now being accommodated. Note that reference numeral 16 denotes a sound deadening member provided so as to surround the electric blower 14.

Further, the blower chamber 10 is communicated with the dust collecting chamber 7 via a filter 17 disposed in the dust collecting section 2, and this filter 17 allows dust and dirt in the dust collecting chamber 7 to be removed from the blower chamber. 10.

As shown in FIG. 2, the electric blower 14 is constructed by disposing an electric motor 19 within a blower case 18, and by attaching a suction fan 21 to the tip of a rotating shaft 20 of the electric motor 19. By operating the electric blower 14, a wind flow (air path) shown by an arrow in FIG. 1 is formed within the cleaner body 1.
The electric motor 19 includes an armature core 22 in which an armature coil is attached to the rotating shaft 20, and a field core 23 in which a field coil is attached to the outer circumference of the armature core 22.
Further, 24 is a fan cover of the suction fan 21, and 25 is a rectifying plate for the suction air sucked by the fan 21.

In the case of this embodiment, a light passage section, that is, through holes 26, 26 are provided in the center of the suction fan 21 (rotating member) arranged in the air passage. These through holes 26, 26 are formed concentrically with the rotating shaft 20, and can face the lamp 27 attached to the rectifier plate 25. Also,
A light receiving element 28 made of a photodiode is arranged in front of the electric blower 14. These lamps 27 and light receiving elements 28 are also arranged in the air passage. The light receiving element 28 is fixed, for example, to the wall member 3a constituting the electric motor section 3, and the light receiving element 28 is opposed to the lamp 27 through the through holes 26, 26 and through the suction port 24a of the fan cover 24. It's becoming like that. Therefore, the light emitted from the lamp 27 by the rotation of the fan 21 is intermittently incident on the light receiving element 28 through the through holes 26, 26, and the number of incident optical signals is intermittently incident on the light receiving element 28. The number of rotations of the fan 21 is then measured. That is, the light receiving element 28 is connected to, for example, an energization control mechanism 29 as shown in FIG. This energization control mechanism 29
are the amplifier circuit 30, the input control circuit 31, and the power supply circuit 3.
2 and a switching circuit 33, which amplifies the optical signal obtained by the light receiving element 28 with an amplifier 30 and transmits it to the input control circuit 31. The number of rotations of the suction fan 21, that is, the rotating shaft 20 is detected. Further, in the input control circuit 31, the maximum allowable rotation speed of the rotating shaft 20 to prevent overheating is set in advance, and when the detected rotation speed is lower than this set rotation speed, the power supply circuit 32 and the switching circuit are 33, outputs a control signal for energizing the electric motor 19, and conversely, when the detected rotational speed exceeds the set rotational speed, the switching circuit 33 is opened to stop energizing the electric motor 19. It is designed to output a control signal.

Therefore, according to the above configuration, even if the inside of the dust collection chamber 7 becomes full of dust and dust, the load on the suction fan 21 decreases and its rotational speed increases,
The energization control mechanism 2 determines the rotational speed of the rotating shaft 20 based on the number of optical signals incident on the light receiving element 28.
9, and when the rotation speed of the rotating shaft 20 exceeds the set rotation speed, the electric blower 14 is forcibly stopped energizing the electric motor 19.
operation can be stopped. Therefore, the rotating shaft 20 of the electric blower 14 is not rotated at a rotation speed higher than the maximum allowable rotation speed, and overheating of the electric blower 14 can be reliably prevented. Further, since the rotation speed of the rotation shaft 20 is electrically detected based on the optical signal incident on the light receiving element 28, the rotation speed of the rotation shaft 20 is accurately determined to operate the energization control mechanism 19. It is possible to increase the reliability of the safety device. Moreover, as described above, from the lamp 27 to the light receiving element 28
Since the rotation speed of the electric blower 14 is directly detected based on the number of optical signals incident on the electric blower 14 and the power supply to the electric blower 14 is controlled, the detection accuracy is high and there is no problem other than a malfunction of the electric blower 14. Detection is ensured. Furthermore, since the optical detection means using the lamp 27 and the light receiving element 28 as described above is adopted as a means for detecting the rotation of the electric blower 14, these do not become a load on the rotation of the electric blower 14. At the same time, there is almost no resistance to the air path, and since the optical detection means has no mechanically moving parts, the possibility of failure is extremely low, and the structure is extremely simple, making it cost-effective. It's advantageous. Furthermore, in this embodiment, since the lamp 27 and the light receiving element 28 are arranged in the air path, it is possible to prevent fine dust that has passed through the filter 17 from adhering to them and damaging their functions due to the wind.

Further, in this embodiment, since the suction fan 21 itself has through holes 26, 26 formed therein, the rotating shaft 20
There is no need to provide a separate rotating member for detecting the rotational speed of the motor, and there is no need to increase the number of parts.

Note that this invention is not limited to the above embodiment. For example, as shown in FIG.
4 and 34, and the light receiving element 28 may be fixed to the inner surface of the fan cover 24.

Further, as shown in FIG. 5, the rotating shaft 20 may be made to protrude outside the blower case 18, and the rotating member 35 having the slits 34, 34 may be attached to this protruding portion. It has the advantage that a conventional electric blower can be used with little modification.

As explained above, this invention uses a lamp and a light-receiving element interposed between a rotating member that is installed on a rotating shaft and is driven to rotate integrally with the rotating shaft, so that the light that passes through the light passing portion of the rotating member is The number of rotations of the rotating shaft of the electric blower is directly detected based on the number of signals received by the light receiving element, and the energization of the electric blower is controlled based on the number of rotations. be. Therefore, since the rotational speed of the electric blower is directly detected and controlled, it is possible to prevent the electric blower from rotating beyond the permissible rotational speed with high precision, and the above-mentioned direct detection allows detection of malfunctions in other parts. Since it is not affected, detection reliability is extremely high, and overheating of the electric blower can therefore be reliably prevented. Moreover, as a detection means for performing the above-mentioned direct detection,
Because it uses a lamp and a light receiver, this detection means is not only cost-effective compared to generators, etc., but also does not create large air path resistance or load on electric blowers, and is simple in structure and durable. It also has excellent properties.

[Brief explanation of the drawing]

1 to 3 show an embodiment of this invention, in which FIG. 1 is a cross-sectional view of the whole, FIG. 2 is a cross-sectional view of an electric blower, and FIG. 3 is a circuit diagram showing an energization control mechanism.
4 and 5 show other embodiments, FIG. 4 being a partial sectional view of the electric blower, and FIG. 5 being a sectional view of the blower chamber. 1...Vacuum cleaner body, 14...Electric blower, 20
... Rotating shaft, 21 ... Suction fan (rotating member),
26...Through hole (light passage part), 27...Lamp,
28... Light receiving element, 29... Energization control mechanism, 34
...Slit (light passage part), 35...Rotating member.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A vacuum cleaner body, an electric blower built into the vacuum cleaner body, a rotating member provided on the rotating shaft of the electric blower and rotationally driven integrally with the rotating shaft, a lamp provided facing the rotating member; a light passing portion formed on the rotating member; a light receiving element provided facing the rotating member and sensing an optical signal passing through the light passing portion; The invention is characterized by comprising an energization control mechanism that detects the number of rotations of the rotating member based on the number of optical signals incident on the light receiving element, and controls energization of the electric blower based on the detected number of rotations. vacuum cleaner. (2) The vacuum cleaner according to claim 1, wherein the rotating member is a fan of an electric blower.