JPH06143998A - Air purifier - Google Patents

Abstract

PURPOSE:To prevent the secular deterioration of the dust-collecting capacity and improve the stable capacity for a long time by adjusting the applied voltage to a charged part so as to agree with the reference value when the current value of the charged part detected by a detecting means is deviated from the reference value. CONSTITUTION:A filter 15 is mounted downstream of a blower 7 of an air conditioning duct 2, and a charged part 16 and a dust-collecting part 17 of an air purifier are arranged between the filter and a heat exchanger 8. This charged part 16 is provided with a discharge electrode 18 connected to a voltage control part 22 and a discharge counter electrode 19 to be earthed through a detecting part 20, and the signal to be detected by the detecting part 20 is received by a comparing part 21 and compared with the reference value, and the deviation signal is outputted to the voltage control part 22. This voltage control part 22 changes the output of the DC variable power source so as to make the deviation zero. Thus, the secular deterioration of the dust-collecting capacity is prevented and the dust-collecting capacity can be stabilized for a long time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air cleaning device incorporated in an air conditioning duct of an air conditioner for an automobile or the like.

[0002]

2. Description of the Related Art As an air cleaner of this type, for example, the one disclosed in Japanese Utility Model Publication No. 57-47211 is known.

In this system, a charging unit (ionizer) and a dust collecting unit are arranged in this order on the downstream side of a blower unit and on the upstream side of a heat exchanger. The charging unit connects a discharge electrode and a discharge counter electrode. Two different electrodes are made to face each other, and by applying a voltage, dust particles passing between the electrodes are charged. The dust particles charged here are collected by the rear dust collecting portion.

[0004]

However, the voltage applied to the charging section is as high as 5 to 6 KV, and if the discharge electrode is a wire having a circular cross section as shown in FIG. 7, it will be used for a while. In this case, dust in the air adheres to the wire surface, and as shown in FIG. 8, if it has needle-like pointed protrusions, the pointed portion gradually wears out, and in any case, discharge occurs. There is a drawback that the current is lowered and the dust collecting ability is lowered. In fact, as shown in FIG. 9, it has been confirmed that the discharge current is reduced to less than half by the operation for several tens of hours, and the dust collection rate is also reduced to less than half with it.

On the other hand, in the dust collecting portion, dust particles accumulate on the surface of the dust collecting portion with the lapse of time, and as a result, the dust collecting ability gradually decreases. Therefore, conventionally, it has been necessary to clean the dust collecting portion in a relatively short period of 3 months and 6 months.

[0006] Therefore, it is an object of the present invention to provide an air purifying device which can prevent the deterioration of the dust collecting ability that occurs over time and can obtain a stable dust collecting ability for a long period of time.

[0007]

SUMMARY OF THE INVENTION The gist of the first aspect of the present invention is, however, that a charging unit for charging dust particles is provided upstream of a heat exchanger in an air conditioning duct, and a charging unit for charging the dust particles. Also in the air purifying apparatus comprising a dust collecting portion which is located on the downstream side and collects the charged dust particles, a detecting means for detecting a current value of the charging portion, and the detecting means detects the current value. Comparing means for comparing a current value with a reference value, and a voltage applied to the charging portion so that the current value of the charging portion matches the reference value when the current value detected by the detecting means deviates from the reference value. And voltage control means for adjusting.

The gist of the second invention is as follows.
An upstream side of the heat exchanger in the air-conditioning duct is provided with a charging part for charging the dust particles, and a dust collecting part located downstream of the charging part for collecting the charged dust particles. In the air purifying apparatus, the dust collecting section includes a grounded low-voltage side electrode and a high-voltage side electrode that floats in opposition to the low-voltage side electrode. There is provided a float electrode capable of varying the distance to the dust collecting part, and a control means for controlling the distance between the float electrode and the charging part to adjust the voltage induced in the dust collecting part.

[0009]

Therefore, according to the first aspect of the present invention, when dust is attached to the discharge electrode or the discharge electrode is worn and the discharge current is reduced, the current value detected by the detecting means is the reference value. Less than. The comparison means detects the deviation of the detected current value from the reference value, and the control section controls the voltage applied to the charging section to be high so as to eliminate the deviation so that the reference current flows. Therefore, a constant discharge current can be obtained regardless of the passage of time.

Further, according to the second aspect of the present invention, even if dust is accumulated on the surface of the dust collecting portion, the ion current supplied from the charging portion to the float electrode can be provided by bringing the float electrode close to the charging portion by the control means. And the bias voltage generated on the high-voltage side of the dust collecting part increases, and the dust collecting ability lowered due to the accumulation of dust can be restored, and therefore, the above-mentioned problems can be achieved. Is.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIG. 1 shows a case where the air cleaning device is installed in, for example, an air conditioner for an automobile. The air conditioner 1 for an automobile is provided with an intake door switching device 3 on the most upstream side of an air conditioning duct 2. In the door switching device 3, an intake door 6 is arranged at a portion where the inside air inlet 4 and the outside air inlet 5 are separated, and the intake door 6 is operated by an actuator to select the air introduced into the air conditioning duct 2 between the inside air and the outside air. You can do it.

The blower 7 sucks air into the air conditioning duct 2 and blows it to the downstream side. A cooling heat exchanger 8 and a heating heat exchanger 9 are provided on the downstream side of the blower 7. It is provided.

The heat exchanger 8 for cooling is connected with a compressor, a condenser, a liquid tank and an expansion valve to form a cooling cycle, and cools the air sent from the blower 7. The heat exchanger 9 for heating is adapted to circulate the cooling water of the engine and heat the air passing therethrough. An air mix door 10 is provided in front of the heat exchanger 9 for heating, and by adjusting the opening degree of the air mix door 10 with an actuator, air flowing through the heat exchanger 9 for heating is changed. The amount of air bypassing the heat exchanger 9 for heating is changed, and as a result, the temperature of the blown air is controlled.

The downstream side of the air conditioning duct 2 is divided into a defrost outlet 11, a vent outlet 12 and a heat outlet 13 and opens into the vehicle compartment. A desired blowout mode is obtained by operating the mode doors 14a, 14b, 14c with an actuator.

On the downstream side of the blower 7, there is provided a pre-filter 15 for removing coarse dust and dirt mixed in the air, and between the pre-filter 15 and the heat exchanger 8 for cooling. A charging unit (ionizer) 16 and a dust collecting unit 17 of the air cleaning device described below are arranged.

The charging section 16 includes a discharge electrode 18 connected to a voltage control section 22 described below, and a discharge counter electrode 19 which is alternately arranged so as to face the discharge electrode 18 and is grounded via a detection section 20. The dust particles passing between the discharge electrode 18 and the discharge counter electrode 19 are charged.

The detection unit 20 detects the actual discharge current flowing through the discharge counter electrode 19 and outputs a detection signal x. The detection signal x detected by this detection unit 20 is input to the comparison unit 21. .

The comparator 21 compares the input detection signal x with
The comparison is made with a reference value x ₀ corresponding to the required discharge current of the charging section 16, and a deviation of the detection signal x from the reference value x ₀ is calculated and a deviation signal (Δx) is output to the voltage control section 22. ing.

The voltage controller 22 has a DC variable power source,
The positive electrode side of this DC variable power source is connected to the discharge electrode 18, and the negative electrode side is grounded, and the deviation signal (Δ
x), the output voltage v of the DC variable power supply is varied so that this Δx becomes zero. If the output voltage v rises too much, sparks may be generated between the electrodes. Therefore, the voltage control unit 22 is provided with a limiter mechanism for keeping the output voltage v lower than the spark generation voltage v _s .

The detection signal x from the detector 20 is input to the spark detector 23. The spark detection unit 23 detects the presence or absence of a pulse signal because a pulse current is generated by the generation of the spark, and when the pulse signal is detected, the voltage control unit 22 receives the voltage stop signal s ₁ . Along with the transmission, the display signal s ₂ is transmitted to the abnormality indicator 24.

The voltage controller 22 controls the voltage stop signal s ₁
When the voltage is received, the applied voltage to the charging unit 16 is set to zero, and
When the abnormality indicator 24 receives the display signal s ₂ , the abnormality indicator 24 displays the abnormality by means such as lighting an abnormality indicator lamp and displaying an abnormality message.

On the other hand, the dust collecting unit 17 includes the charging unit 16
A high voltage side electrode 26 connected to the positive electrode side of the DC power source 25 and a low voltage side electrode 27 connected to the negative electrode side of the DC power source are alternately arranged.
The charged dust particles are the high voltage side electrode 26 and the low voltage side electrode 27.
These dust particles are adsorbed when trying to pass between and.

In the above-mentioned structure, when the initial applied voltage to the charging section 16 is 6 KV, the dust particles in the air discharged from the upstream due to discharge between the discharge electrode 18 and the discharge counter electrode 19 are The dust particles, which are charged when passing between the discharge electrode 18 and the discharge counter electrode 19, are collected by the rear dust collecting portion 17. When dust adheres to the discharge electrode 18 or the discharge electrode 18 wears with the passage of time, the discharge current changes from the characteristic line at the initial stage of use shown by the solid line in FIG. 2 to the characteristic line shown by the broken line. However, in this case, the detection signal x detected by the detection unit 20
Becomes smaller than the reference value x ₀ , a deviation signal (Δx) corresponding to the deviation is output from the comparison unit 21, and the voltage control unit 22 raises the applied voltage so that this Δx becomes zero.
Make the discharge current the same as at the beginning of use. Therefore, the discharge current remains constant without change over time, and the initial charging ability is maintained.

It is known that the characteristics of the voltage applied to the charging section 16 and the discharge current increase exponentially as the voltage increases as shown in FIG. 2, and the voltage is, for example, 6.1K.
If the voltage is boosted to V, the discharge current changes by several tens of μA, so it is not necessary to greatly boost the voltage for adjusting the discharge current.

FIG. 3 shows an embodiment of the air purifying apparatus according to the second invention. Below, different parts will be described, and the same parts will be denoted by the same reference numerals and description thereof will be omitted.

The charging section 16 of the air cleaning device has a discharge electrode 1 connected to the positive electrode side of a DC power supply 30 whose negative electrode side is grounded.
8 and the discharge counter electrode 19 set to the ground voltage are alternately arranged. On the other hand, the dust collector 17 is
The low-voltage side electrode 27 set to the ground voltage and the high-voltage side electrode 26 that is alternately arranged with the low-voltage side electrode 27,
The high voltage side electrode 26 is designed so as not to be connected to a power source or a ground.

A float electrode 31 is arranged between the charging section 16 and the dust collecting section 17, and the float electrode 31 floats on the high voltage side electrode 26 of the dust collecting section 17 from the power source and ground. Connected.

Thus, the voltage applied to the charging section 16 causes the discharge electrode to discharge to the discharge counter electrode, while the discharge electrode 18 supplies an ionic current to the float electrode 31, and the high-voltage side electrode of the dust collecting section 17 is supplied. 26, a bias voltage is automatically generated, and the dust particles charged in the charging unit 16 are adsorbed on the surface of the dust collecting unit 17 when passing between the high voltage side electrode 26 and the low voltage side electrode 27. It

The float electrode 31 has a rack 33 formed at the base thereof for meshing with the gear 32.
When the motor 2 is rotationally controlled by the motor 34, the distance d from the charging unit 16 is variable.

Further, a humidity sensor 35 for detecting the humidity of the introduced air is attached between the pre-filter 15 and the charging section 16, and the output signal of the humidity sensor 35 is
It is adapted to be input to the control unit 36.

The control unit 36 includes an input circuit including an A / D converter and a multiplexer, a timer, and an RO.
It is a known one having an arithmetic processing circuit including M, RAM, CPU, etc., and an output circuit including a driving circuit, etc., and is adapted to drive and control the motor 34 connected to the gear 32 according to a predetermined program. .

Next, an example of driving operation of the motor 34 by the control unit 36 will be described.

The distance d between the float electrode 31 and the charging section 16
As shown in FIG. 4, the potential difference between the high-voltage side electrode 26 and the low-voltage side electrode 27 of the dust collecting part 17 (ground voltage of the high-voltage side electrode) due to the change in Therefore, even if the dust collecting ability gradually decreases due to accumulation of dust particles in the dust collecting portion 17, if the float electrode 31 is brought closer to the charging portion 16, the dust collecting ability can be kept constant. it can.

Therefore, the control unit 36 is
The built-in timer measures the cumulative operation time of the electrostatic precipitator, and the motor 3 is configured to gradually reduce the distance d between the charging unit 16 and the float electrode 31 as the cumulative operation time increases.
4 is driven continuously or stepwise. More specifically, as shown in FIG. 5, for example, in order to obtain a target dust collection rate, the float electrode 31 and the charging unit 1 in the initial stage of use are used.
When the distance d from 6 is 3 mm, the characteristic curve of the dust collection rate gradually shifts downwards with time. Therefore, in order to obtain the target dust collection rate in the initial stage of use, the float collection rate is about 6 months later. The distance between the electrode 31 and the charging unit 16 is set to 2 mm, and about 1 m after one year.
Change to m.

As shown in FIG. 6, the dust collecting portion 17 has a low discharge efficiency and a low dust collecting ability when the humidity is high, and a high dust collecting ability when the humidity is low. The dirt on the surface of the dust collecting part is accelerated. Therefore, the control unit 36 calculates the deviation from the reference humidity based on the signal from the humidity sensor 35, and when it is higher than the reference humidity, the distance d between the float electrode 31 and the charging section 16 is reduced. When the motor 34 is driven and the humidity is lower than the reference humidity, the motor 34 may be driven so as to increase the distance d between the float electrode 31 and the charging unit 16 to maintain a constant target dust collection rate.

In this embodiment, the means for changing the distance d between the float electrode 31 and the charging section 16 is constituted by the gear 32 connected to the motor 34 and the rack 33 of the float electrode 31. Alternatively, the expansion / contraction of the piezoelectric ceramic may be used to adjust the voltage applied to the piezoelectric ceramic to change the distance d between the float electrode 31 and the charging portion 16.

[0038]

As described above, in the first invention, the applied voltage of the charging section is adjusted so that the discharge current of the charging section becomes constant, and in the second invention, the dust collecting section. Since the distance between the float electrode and the discharge electrode of the charging part is adjusted, it is possible to prevent the deterioration of the dust collection performance that occurs over time in any case, and to obtain a stable dust collection performance for a long time. Is.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment in which an air cleaning device according to a first aspect of the invention is used in an air conditioner for an automobile.

FIG. 2 is a characteristic diagram showing the relationship between applied voltage and discharge current.

FIG. 3 is a configuration diagram showing an embodiment in which the air cleaning device according to the second invention is used in an air conditioner for an automobile.

FIG. 4 is a characteristic diagram showing the relationship between the distance d between the float electrode and the charging section and the ground voltage of the high voltage side electrode.

FIG. 5 is a characteristic diagram showing the relationship between the dust collection rate and the distance d between the float electrode and the charging section with the lapse of time.

FIG. 6 is a characteristic diagram showing the relationship between the dust collection rate and the distance d between the float electrode and the charging part due to a change in humidity.

FIG. 7 is a cross-sectional view showing an example of a discharge electrode of a charging section.

FIG. 8 is an explanatory diagram showing another example of the discharge electrode of the charging section.

FIG. 9 is a characteristic diagram showing changes over time in dust collection rate and discharge current.

[Explanation of symbols]

 2 Air-conditioning duct 8 Heat exchanger for cooling 9 Heat exchanger for heating 16 Charging part 17 Dust collecting part 20 Detection part 21 Comparison part 22 Voltage control part 26 High voltage side electrode 27 Low voltage side electrode 31 Float electrode 36 Control unit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shoichi Masuda No.415, 3-2-1 Nishigahara, Kita-ku, Tokyo

Claims (2)

[Claims] 1. A charging unit for charging dust particles upstream of a heat exchanger in an air-conditioning duct, and a collector for collecting charged dust particles positioned downstream of the charging unit. In an air cleaning device comprising a dust part, a detection means for detecting the current value of the charging part, a comparison means for comparing the current value detected by the detection means with a reference value, and the detection means for detecting the current value. And a voltage control unit that adjusts the voltage applied to the charging unit so that the current value of the charging unit matches the reference value when the current value deviates from the reference value. 2. A charging unit for charging dust particles upstream of the heat exchanger in the air-conditioning duct, and a collector for collecting the charged dust particles positioned downstream of the charging unit. In an air purifying apparatus comprising a dust part, the dust collecting part comprises a grounded low-voltage side electrode and a high-voltage side electrode that faces the low-voltage side electrode and floats. A float electrode that is connected to the charging unit and that can change the distance to the charging unit is provided, and a control unit that controls the distance between the float electrode and the charging unit to adjust the voltage induced in the dust collecting unit is provided. A characteristic air purifier.