JPS6246166B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cord winding device for a vacuum cleaner, which allows the power cord to be easily stored with a single touch after using the vacuum cleaner, improves durability, and is easy to assemble during the manufacturing process. The purpose is to make it easier.

Conventional cord winding devices rely on the restoring force of the mainspring as a power source, which requires a large pulling force when pulling out the power cord, and with repeated use, this restoring force decreases, which limits its durability. Furthermore, during assembly during the manufacturing process, the mainspring had to be wound and inserted, resulting in a troublesome process.

The present invention solves the above-mentioned conventional drawbacks, and one embodiment thereof will be described below with reference to the accompanying drawings.

In the figure, 1 is a fixed shaft fixed to 1 base plate 2. Reference numeral 3 denotes a cord reel, around which a power cord 4 is wound, so that it can rotate around a fixed shaft 1. Reference numeral 5 denotes a thin plate of shape memory alloy, which is wound in a spiral shape, and is fixed to the fixed shaft 1 at one end and to the cord reel 3 at the other end. 6 is a stopper for stopping the cord reel 3 arbitrarily. The thin plate 5 of the shape memory alloy is placed at a position where it receives the exhaust heat 7 of the electric blower in the vacuum cleaner.

Here, the term "shape memory alloy" refers to an alloy whose shape changes through phase transformation. In other words, it has a low-temperature phase and a high-temperature phase depending on the temperature, and the low-temperature phase has a martensitic structure, and the deformation imparted in the low-temperature phase is retained in the low-temperature phase, and when it transitions to the high-temperature austenite structure, it has undergone aging treatment beforehand. It changes to the shape it was originally in. In general, the relationship between the transformation force (stress generated during deformation) and temperature of shape memory alloys is
As shown in the figure, the Ms point is the temperature at which martensitic transformation begins, the Mf point is the temperature at which martensitic transformation is completed (complete transition to the low temperature phase), and the As
The point is the temperature at which martensite begins to disappear upon heating, and the Af point is the temperature at which it completely disappears. As shown in FIG. 2, there is generally hysteresis during heating and cooling.

In this embodiment, the shape memory alloy thin plate 5 includes:
Using a Ti-Ni alloy, the temperature at the As point is 45℃, the temperature at the Af point is 60℃, the temperature at the Ms point is 40℃, and the temperature at the Mf point is
With the composition at 25℃ and tightly wound in a spiral shape,
Shape memory treatment (aging treatment) is performed at a temperature of 400 to 500°C.

In the above configuration, when the power cord 4 is pulled when the vacuum cleaner is used, the cord reel 3 rotates, and the spirally wound shape memory alloy thin plate 5 is unwound. At this time, the shape memory alloy thin plate 5 is at room temperature and is in a low temperature phase below the As point (45° C.), so it is soft and requires almost no force to unwind.

When cleaning is performed with the cord reel 3 arbitrarily stopped by the stopper 6, the shape memory alloy thin plate 5 receives the exhaust heat 7 of the electric blower, and the temperature rises until it reaches the A point (45°C). It begins to shift to a high temperature phase, and when it is above the Af point (60°C), it completely shifts to a high temperature phase, hardens, and attempts to restore its original tightly wound spiral shape, winding the power cord 4 around the cord reel 3. It causes stress in the direction. At this time, when the stopper 6 is released, this shape memory alloy thin plate 5
The cord reel 3 rotates due to the deformation force, and the power cord 4
is wound up.

Also, after cleaning, the shape memory alloy thin plate 5 is cooled.
When it reaches the Ms point (40℃), it begins to transition to the low temperature phase again, and below the Mf point (25℃), it completely changes to the low temperature phase and softens, allowing the power cord 4 to be freely pulled out, and the above operation is repeated. It is possible.

Note that in this example, Ti was added to the thin sheet of shape memory alloy.
-Ni alloy is used, but Ti-Ni-Cu alloy, Cu-Zn-Al alloy, etc. may also be used, and the composition also depends on the location receiving the exhaust heat of the electric blower and the ambient temperature in which the vacuum cleaner is used. Even if the temperatures at the Ms point, As point, etc. are set differently from those in this embodiment, the same effect can be obtained.

As described above, according to the present invention, winding can be performed with one touch without requiring almost any force to pull out the power cord. In addition, the shape memory effect of the shape memory alloy used as the power source does not change even after repeated use, so there is no possibility of performance deterioration due to a reduction in the restoring force of the mainspring spring as in the past. Furthermore, since the shape memory alloy is soft at room temperature, it is extremely easy to assemble during the manufacturing process, and is therefore highly effective as a cord winding device for a vacuum cleaner.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a cord winding device according to an embodiment of the present invention, and FIG. 2 is a diagram showing the relationship between transformation force and temperature of a shape memory alloy. 3... Cord reel, 4... Power cord, 5... Shape memory alloy thin plate, 6... Stopper, 7... Exhaust heat.

Claims (1)

[Claims] 1. A power cord wrapped around a cord reel,
It has a spiral shape memory alloy thin plate attached to the cord reel and a stopper for locking the cord reel, and when the power cord is pulled out at room temperature, the shape memory alloy thin plate is unwound and the electric blower is activated during operation. A cord winding device for a vacuum cleaner, which is characterized by transferring to a memory shape on the high temperature side by exhaust heat of the vacuum cleaner, and storing energy in a thin plate of the same shape memory alloy.