JPS5934835Y2 - hot air blower - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a hot air blowing device such as a hair dryer that includes a heater made of a positive temperature coefficient thermistor having a through hole for ventilation.

Recently, positive temperature coefficient thermistors are equipped with many through holes for heat dissipation to greatly increase the surface area per unit volume, making it possible to generate a practical amount of heat of several hundred watts, such as hair dryers that use heaters. A hot air blower was devised, but it has the following practical problems.

In other words, all the air sent by the fan is blown out of the main body of the device through the through hole of the PTC thermistor heater, but because the pressure loss when flowing through the heater is large, it is difficult to obtain a sufficient amount of air. Therefore, it is necessary to use a fan motor with a larger air blowing capacity than one using a normal nichrome wire heater.

This idea was devised based on the above-mentioned circumstances, and its purpose is to be able to obtain a sufficient amount of air at the outlet side without using a fan motor with a particularly large air blowing capacity. The purpose of the present invention is to provide a hot air blower.

This invention will be described below with reference to embodiments shown in FIGS. 1 to 3.

Reference numeral 1 in FIG. 1 denotes a main body of the apparatus, which has a suction port 2 bored in its upper rear surface, and a cylindrical air outlet 3 projecting forward in its upper front surface.

Furthermore, a fan motor 5 having a fan 4 is provided in the upper part of the device main body 1, and this allows the fan 4 to be connected to the air outlet 3.
The air sucked from the suction port 2 into the ventilation path leading to the air outlet 2 is ventilated toward the blowout port 3.

Note that 6 is a motor support that supports the fan motor 5, and this has a structure (not shown) that does not obstruct ventilation.

Furthermore, a heater 7 formed by a positive temperature coefficient thermistor provided with a large number of through holes 7a for ventilation is disposed inside the air outlet 3.・
. . forms an auxiliary ventilation path 8 that bypasses.

In this embodiment, the heater 7 is housed in a cylindrical body 9 with both ends open, and the cylindrical body 9 is supported by a plurality of support arms 10 protruding inside the air outlet 3. It is arranged concentrically within the outlet 3, and as a result, an auxiliary ventilation passage 8 is formed between the outer peripheral side of the cylindrical body 9 and the outlet 3.

Of course, the amount of air passing through the cylinder 9, that is, the through hole 7a of the heater 7
The ratio of the air volume passing through ... and the air volume passing through the auxiliary ventilation path 8 is,
The air volume passing through the through holes 7a is set to be larger.

In the figure, reference numeral 12 denotes an airflow rate control mechanism that is provided as necessary to adjust the airflow rate passing through the through holes 7a of the heater 1.
This is because the heater 7 made of a positive temperature coefficient thermistor having the through holes 7a has a characteristic that the amount of heat generated changes depending on the amount of air passing through it, as shown in Fig. 4, so there is no need to control the rotation speed of the fan 4. This is provided to change the amount of heat generated by the heater 7.

That is, to explain this control mechanism 12, a female thread 13 is formed on the inner circumferential surface of the air outlet 3, and a male thread 15 of an air outlet body 14 is screwed into this so as to be freely retractable.

The air outlet body 14 has a cylindrical shape as shown in FIGS. 1 and 2, has a male thread 15 carved in its rear part, and has a conical air volume adjusting protrusion facing the outlet of the cylindrical body 9 at the center of the interior. 16 is attached via a plurality of arms 17.

This airflow control mechanism 12 inserts and removes the airflow adjustment protrusion 16 from the outlet of the cylinder body 9 by moving the air outlet body 14 forward and backward, thereby adjusting the airflow that passes through the through holes 7a of the heater 7. It is.

The lower part of the main body 1 of the apparatus is formed as a grip part 18, and the grip part 18 is provided with a switch device 19.

This device 19 has a hot air position where the fan motor 5 and the heater 11 are turned on at the same time, a cold air position where only the fan motor 5 is turned on, and a cold air position where the fan motor 5 and the heater 11 are turned on at the same time.
It has a cutting position for FF.

Note that 20 in FIG. 1 is a power plug.

By the way, the vertical axis in FIG. 3 shows the static pressure of the fan motor 5.
The horizontal axis indicates the amount of air passing through the through holes 7a of the heater 7, and as shown by curve A in the figure, the amount of air Q2
(7?fl/min) increases, the pressure loss due to the heater 11 increases.

However, the pressure loss is not only caused by the heater 11, but also by the air volume adjustment protrusion 16 in this embodiment, so the actual pressure loss is caused by, for example, three curves B... As shown, the air volume changes in a steep rise depending on the position of the air volume adjustment protrusion 16.

That is, by adjusting the air volume adjustment protrusion 16, the air volume Q2 (m
Even if the change in '/m1n) is small, the static pressure can be greatly changed.

In addition, the curve C in the same figure shows the change in the total air volume.

Next, the operation of the embodiment configured as above will be explained.

When the power plug 20 is inserted into an outlet (not shown) and the outlet body 14 is rotated, the switch device 19 is operated to the hot air position, and the fan motor 5 and the heater 11 are energized.

Therefore, the rotation of the fan 4 causes the suction 1 to be drawn from the suction port 2.
The air is ventilated through the through hole 7a of the heater 7 and the auxiliary ventilation passage 8 without passing through the heater 7, and the air passing through the heater 7 is heated on the wall surface of the through hole 7a. be done.

Therefore, the air outlet body 14 is screwed into the air outlet 3 until it stops at the back, and the air volume adjusting protrusion 16 is inserted into the outlet part of the cylinder body 9, and in this state, for example, the total air volume Q is set.

Air volume Q2 (??) of 40% of (rr?/min)
Zs/min) is inside the cylinder 9, and the through hole 7a is
If it is set so that it passes through..., there will be a loss in air volume due to a pressure loss equivalent to 0.4Qo (??Z3/m1n) due to the static pressure-wind pressure characteristics shown in Figure 3, but the remaining 6
Air volume of 0 article Q 1 (m'/min) = Qo Q
2 passes through the auxiliary ventilation path 8 and bypasses the heater 7.

In other words, even if the fan motor 5 does not have a particularly large air blowing capacity, the air volume Q1 is secured by the auxiliary ventilation passage 8, and the air volume Q1 is the sum of the air volume Q1 that has passed through the heater through holes 7a... Since it is obtained as, the total air volume Q.

There is no significant decrease in the air volume compared to the previous model, and a practically sufficient air volume can be obtained.

The air thus ventilated is mixed within the blow-off port body 14 and is blown out as warm air.

In this case, the air flowing out from the heater through holes 7a is diffused around the entire circumference using the conical air volume adjustment protrusion 16 as a guide, so that it is reliably mixed with the air that has passed through the auxiliary ventilation path 8. It is.

In addition, when obtaining this warm air, if the position of the outlet body 14 is adjusted so that the position of the air volume adjustment protrusion 16 is moved away from the cylinder body 9, the pressure loss will be reduced, so the pressure loss will be equivalent to the amount of the decrease. It is possible to increase the blowout air volume, and
As can be seen from the characteristic curve in FIG. 4, since the amount of air passing through the heater 11 increases, its heat dissipation can be activated.

That is, the amount of heat generated by the heater 11 can be greatly changed even though the change in the amount of air blown relative to the total amount of air is so small that it can be practically ignored.

Therefore, by adjusting the outlet body 14, hot air at a desired temperature can be obtained.

Further, when the switch device 19 is operated to the cold air position,
Since the heater 11 does not generate heat, the heater through hole 7a...
The wind passing through the auxiliary ventilation passage 8 is blown out as cold air 11, and in this case as well, a sufficient amount of air can be obtained as in the case of obtaining warm air.

At this time, when the air outlet body 14 is operated so that the air volume adjusting protrusion 16 is completely removed from the outlet of the cylinder body 9,
Although there is an air volume loss due to the pressure loss due to the heater 11, the total air volume is Q.

It is possible to obtain a blowout air volume that is approximately equal to , and it is possible to obtain cold air most effectively.

Note that this invention is not limited to the above-mentioned embodiments, and when implementing this invention, the main body of the device, the air outlet, the ventilation passage, the heater, and its through-holes may be Of course, the structure, shape, arrangement, etc. of the auxiliary ventilation passages, etc. can be implemented in various configurations.

As explained above, this invention is characterized in that by disposing a heater made of a positive temperature coefficient thermistor in the ventilation path of the main body of the device, an auxiliary ventilation path that bypasses the heater is formed in this ventilation path. .

Therefore, this invention has the effect that a sufficient amount of air can be blown out without using a fan motor having a particularly large air blowing capacity.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing an embodiment of this invention, Fig. 2 is a front view showing the outlet body of the same embodiment, and Fig. 3 is a characteristic showing the relationship between static pressure and air volume of the same embodiment. It is a curve diagram. FIG. 4 is a characteristic curve diagram showing the relationship between the amount of heat generated by the heater used in this invention and the amount of air passing through it. 1...Device main body, 2...Suction port, 3...Blowout port,
4...Fan, 5...Fan motor, 7,21...
·heater,? a, 21a... through hole, 8... auxiliary ventilation path.

Claims (1)

[Scope of utility model registration request] A heater made of a positive temperature coefficient thermistor having a large number of through holes for ventilation is provided, and the heater is arranged in the ventilation passage so that ventilation is conducted through the through holes, and the heater is arranged in the ventilation passage by the arrangement of and. A hot air blower formed by forming an auxiliary passageway that bypasses the through-hole.