JP2002374670A - Circuit module for ion generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit module for an ion generator, which can always stably generate a high voltage for generating ions by a piezoelectric transformer, even when the power source voltage usable according to an application utility is different and hence which has compact and superior general-purpose properties. SOLUTION: The circuit module 1 for the ion generator comprises the step-up piezoelectric transformer 70, a high-voltage power source circuit 41 including a drive DC-AC converter 42 for generating a primary side drive AC of the transformer 70 which is converted from a DC (heretofore referred to as a 'drive source DC') of a predetermined voltage, a DC power source circuit 36 capable of inputting external DCs of voltages of a plurality of types for converting an external DC input into a drive source DC of a predetermined constant voltage, irrespective of the input voltage, and a board 31 having their electrode connectors 27a, the circuit 41 and the circuit 36 integrally mounted thereon.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an ion generator.

[0002]

2. Description of the Related Art Conventionally, an ion generator has been used to purify, sterilize, or deodorize air in a room or an automobile. In many of these, an AC power supply unit, a step-up transformer and a needle electrode are arranged in a housing, and a high AC voltage boosted by the transformer is applied to the needle electrode to generate corona discharge, and the discharge is performed. Is emitted from an ion emission port provided in the housing. The ions generated from the ion generator include negative ions and positive ions.For example, negative ions are said to be superior in terms of purification, deodorization or sterilization effects. It is attracting attention because it is also used in air conditioners. In addition, the interior of a car tends to be contaminated with air, and there is a high demand for mounting a negative ion generator from the viewpoint of improving comfort.

[0003] Recently, in order to make the above-mentioned ion generating device smaller, a device has been proposed in which a high voltage power supply unit for generating ions is formed by using a piezoelectric transformer (for example, Japanese Patent Laid-Open No. -199654 or JP-A-10-199655). The piezoelectric transformer is
By coupling the resonance phenomenon of mechanical vibration to the electric / mechanical energy conversion function of the piezoelectric ceramic element, there is an advantage that a high step-up ratio can be realized while being lighter and more compact than a wound transformer.

[0004]

However, the piezoelectric transformer has various restrictions that are not found in a general wound-type transformer. First, the resonance frequency of the piezoelectric ceramic element, which is the basis of the boosting function, is fixed by the material, dimensions and shape of the element, so that only an alternating current in a limited frequency range can be boosted. Since this frequency is generally quite high, for example, it is impossible to directly boost commercial AC (for example, 50 Hz / 60 Hz), and a driving AC generating circuit including a DC conversion circuit and an oscillation circuit is required. Also,
The drive AC of the piezoelectric transformer is not only limited in frequency but also operates only in a relatively narrow drive voltage range of about 15 to 40 V from the viewpoint of ensuring both durability and high voltage of the piezoelectric ceramic element. Can not do. In this case, the range of the appropriate voltage is further narrowed in consideration of the shape of the element and the like.

As described above, the application range of the ion generator has been rapidly expanding in recent years. However, the DC power supply for driving that can be secured for the piezoelectric transformer has a considerable difference in voltage level depending on the application. is there. For example, a general home appliance such as an air conditioner is often equipped with a 5V DC power supply for driving a microcomputer, hardware logic, or the like, and this is used. On the other hand,
In the case of an automobile, a battery mounted on the vehicle can be used as a DC power supply. The voltage is 12 V for a general gasoline engine vehicle and 24 V for a large diesel vehicle.
It is.

On the other hand, in order to make the most of the compactness of the piezoelectric transformer in the process of assembling the device, it is effective to incorporate a high voltage circuit for generating ions into the substrate together with the piezoelectric transformer to form a module. However, when the power supply voltage differs depending on the application field of the ion generator, a voltage conversion circuit having a different specification must be designed for each voltage to be used in order to generate a DC voltage specialized for the piezoelectric transformer. In addition, it is necessary to prepare various types of modules having voltage conversion circuits having different specifications, which has been a factor of cost increase.

[0007] Further, when an attempt is made to reduce the size of the module, the mounting interval of components on the substrate becomes narrower, and a piezoelectric transformer for generating a high voltage is mounted in a limited space. Even the occurrence of dew condensation or the attachment of foreign matter, etc., may be a cause of trouble such as a short circuit. Therefore, it is indispensable to mold components on the substrate including the piezoelectric transformer with an insulating polymer.

Here, the circuit including the piezoelectric transformer can smoothly vibrate the piezoelectric ceramic element,
In addition, there is a demand that the frequency of the vibration must be stabilized, which is not required for ordinary electric circuits. The present inventors have studied that when performing the above-described molding, the selection of the material greatly affects the output characteristics of the ion generator using the piezoelectric transformer, and a high voltage sufficient for driving is secured depending on the selected material. It was found that there was a problem that the ion generation performance could be impaired.

A first object of the present invention is to enable a stable high voltage for ion generation by a piezoelectric transformer even when the power supply voltage that can be used differs depending on the application. A circuit module for a generator is provided. The second issue is that even if the component mounting density is increased by molding the components on the board, problems such as short-circuits are unlikely to occur, and it is possible to maximize the ion generation performance of the piezoelectric transformer Another object of the present invention is to provide a circuit module for an ion generator.

[0010]

The first configuration of the circuit module for an ion generator according to the present invention comprises an electrode connecting portion for connecting an ion generating electrode in order to solve the first problem. For supplying a high voltage for ion generation to the electrode connection portion, and a step-up piezoelectric transformer and a primary-side driving AC of the piezoelectric transformer are connected to a DC (hereinafter referred to as a predetermined voltage). A high-voltage power supply circuit including a driving DC-AC conversion circuit generated by conversion from a driving source DC) and an external DC of a plurality of types of voltages can be input. To
A DC power supply circuit for converting a drive source DC of a predetermined constant voltage irrespective of the input voltage, and a substrate on which the electrode connection portion, the high-voltage power supply circuit, and the DC power supply circuit are integrally mounted, are provided. It is characterized by the following.

According to the above configuration, external DC of a plurality of types of voltages can be input, and the input external DC is
Regardless of the input voltage, a DC power supply circuit is provided to convert the drive source DC into a predetermined constant voltage drive source, so even if the external DC voltage level that can be used as the drive power source differs depending on the application, as in the past, There is no need to prepare a plurality of types of modules each having a different voltage conversion circuit with different specifications. As a result, a high voltage for ion generation by the piezoelectric transformer can always be stably generated regardless of the type of input voltage, and a compact and versatile circuit module for an ion generator can be realized. Further, the fact that a plurality of types of external direct currents can be processed by a single direct current power supply circuit is also an important advantage in reducing the size of the module.

A second configuration of the circuit module for an ion generator according to the present invention includes an electrode connecting portion for attaching an ion generating electrode to solve the second problem.
This is for supplying a high voltage for generating ions to the electrode connecting portion. The piezoelectric transformer for boosting and the primary side driving AC of the piezoelectric transformer are connected to a DC (hereinafter referred to as a driving source) of a predetermined voltage. A high-voltage power supply circuit including a driving DC-AC conversion circuit generated by conversion from DC), a substrate on which the electrode connection portion and the high-voltage power supply circuit are integrally mounted, and And a polymer material molding section for molding a piezoelectric ceramic element of the piezoelectric transformer together with components of a high-voltage power supply circuit, and the polymer material molding section is JIS: K-6.
253 (1997) is characterized by being made of a rubber or an elastomer having a durometer hardness of 80 or less in a type A durometer.

In a conventional electronic circuit board, a circuit component is often molded with a relatively hard polymer material such as an epoxy resin in order to give priority to prevention of noise and improvement of strength. However, the present inventors have studied that when such a hard mold covers the piezoelectric transformer provided on the ion generating device circuit board, the vibration of the piezoelectric ceramic element is restrained, and smooth vibration is hindered. As a result, it was found that a sufficient output voltage and, consequently, an ion generation performance could not be obtained. In addition, the rigid mold enhances the mechanical coupling between the piezoelectric ceramic element and the peripheral components such as the substrate and the case, so that a parasitic resonance mode due to coupled vibration and the like is likely to occur, which also reduces the output of the piezoelectric transformer. Contributes to

Therefore, as a result of further study, the problem of vibration restraint of the piezoelectric ceramic element is remarkably solved by forming the polymer material mold portion from rubber or elastomer having the above-mentioned hardness, and smoothness is achieved. Vibration becomes possible, and as a result, the output voltage of the piezoelectric transformer decreases,
As a result, it has been found that a decrease in ion generation performance can be effectively suppressed. In addition, as described above, by adopting a moderately flexible rubber or elastomer as a material of the mold portion, the vibration of the piezoelectric ceramic element is elastically absorbed by the mold portion, and mechanical vibration with peripheral components such as a substrate and a case. Is reduced. As a result, a decrease in output due to a parasitic resonance mode or the like hardly occurs.

On the other hand, a third configuration of the circuit module for an ion generator according to the present invention includes an electrode connecting portion for attaching an ion generating electrode, and an electrode connecting portion for solving the second problem. It is for supplying a high voltage for generating ions, and includes a step-up piezoelectric transformer and a primary-side drive AC of the piezoelectric transformer, which is supplied from a DC of a predetermined voltage (hereinafter referred to as a drive source DC). A high-voltage power supply circuit including a driving DC-AC conversion circuit generated by conversion, a substrate on which the electrode connection portion and the high-voltage power supply circuit are integrally mounted, and a piezoelectric transformer on the substrate A polymer material coating section for coating the piezoelectric ceramic element together with the components of the high-voltage power supply circuit. Coating thickness which is equal to or is 1mm or less.

In the third configuration, the polymer material mold portion of the second configuration is replaced with a polymer material coating portion, and the coating thickness of the coating portion on the piezoelectric ceramic element is 1 mm or less. . in this way,
By reducing the thickness of the coating on the piezoceramic element, the problem of vibration constraint of the piezoceramic element is remarkably solved, enabling smooth vibration, and as a result, the output voltage of the piezoelectric transformer is reduced and, consequently, the ion generation performance is reduced. Can be effectively suppressed. The outer coating thickness is desirably 0.1 mm or more from the viewpoint of sufficiently improving the strength of the substrate or preventing effects such as noise.

The above-described second to third configurations can be implemented in combination with the first configuration. As a result, a high-performance, excellent versatility and compact circuit module can be realized.

[0018]

Embodiments of the present invention will be described below with reference to embodiments shown in the drawings. FIG. 1 shows the appearance of a circuit module for an ion generator (hereinafter, also simply referred to as a circuit module) 1 according to one embodiment of the present invention. The circuit module 1 includes the ion generating electrode 27
Electrode connecting portion 27a for connecting the
a high-voltage power supply circuit (described later) having a piezoelectric transformer 70 for supplying a high voltage for generating ions to a, and a DC power supply for supplying a DC current as a drive source current to the high-voltage power supply circuit A circuit (to be described later) is integrated with a substrate 31 made of a glass-epoxy resin composite material or the like. Further, on the substrate 31, there is provided a polymer material molding section 30 for molding the piezoelectric ceramic element of the piezoelectric transformer 70 together with the components of the high-voltage power supply circuit. The polymer material mold portion 30 is made of rubber or elastomer having a type A durometer hardness of 80 or less specified in JIS: K-6253 (1997).
The operation and effect of adopting a rubber / elastomer having such hardness have already been described.

If the hardness of the polymer material mold portion 30 exceeds 80 in the type A durometer hardness, the output of the piezoelectric transformer 70 tends to decrease. The lower limit of the hardness is not particularly limited, but if the hardness is up to about 1, there is an advantage that it can be selected from commercially available rubber.
If the hardness is extremely low, the mold-retaining function as a mold may not be maintained in some cases, and it is desirable to select the hardness within a range in which such a problem does not occur. The hardness of the polymer material mold section 30 is more desirably selected in the range of about 10 to 50.

The material of the rubber / elastomer to be employed is not particularly limited as long as it satisfies the above-mentioned hardness range, but a liquid rubber / elastomer (for example, silicone or urethane) in an uncured state at normal temperature is used. When used,
Molding by casting can be performed easily. In the present embodiment, the substrate 31 is housed in the case 35, and in a state where the substrate 31 is arranged in the case 35, a rubber or an elastomer (of course, in a liquid state) is cast and then cured. Thus, the component C of the circuit mounted on the board 31 is molded together with the board 31 in the case 35.

In the case 35, specifically, an opening 35c for accommodating the substrate 31 is formed on the upper surface side.
1 is arranged in the case 31 so as to be floated from the bottom surface by a predetermined distance by a spacer 35a (protruded from the case bottom surface) so that the component C disposed on the back surface side of the substrate does not contact the case bottom surface. I have. In addition, a penetration portion 31a for discharging gas filling the space on the back surface side of the substrate at the time of casting is formed in the thickness direction. Thus, it is possible to prevent or suppress a problem that bubbles and the like remain around the base after casting and the corrosion resistance and the like are impaired.

The substrate 31 is fixed to the spacer 35a by a fastening member 35b such as a bolt. A base end of a high-voltage output cable 27b is connected to an electrode connecting portion 27a formed on the surface of the substrate 31, and the opposite side extends out of the mold portion 30 and has an ion generating electrode 27 is attached.

Instead of molding the substrate 31 as described above, a configuration in which the entire substrate 31 is covered with a polymer material coating portion 130 as shown in FIG. 1C can be adopted. In this case, the polymer material coating section 1
Instead of limiting the hardness of 30, the coating thickness (average value) t of the piezoelectric ceramic element 70 may be set to 1 mm or less (0.1 mm or more). In addition, as the material of the polymer material coating portion 130, urethane resin, acrylic resin, epoxy resin, or the like can be used.

FIG. 2 is a block diagram showing an example of a circuit configuration of the circuit module. The harmful circuit includes the high-voltage power supply circuit 41 and the DC power supply circuit 36 as described above. The high-voltage power supply circuit 41 is for supplying a high voltage for generating ions to the electrode connecting portion 27a. The high-voltage power supply circuit 41 includes a piezoelectric transformer 70 for boosting and a primary-side driving AC of the piezoelectric transformer 70, which is determined in advance. And a driving DC-AC conversion circuit 42 that is generated by converting the output voltage from DC (drive source DC). Further, the DC power supply circuit 36 is capable of inputting a plurality of types of external DC, and converts the input external DC into a drive source DC of a predetermined constant voltage irrespective of the input voltage. It is. These electrode connection portions 27a
The high-voltage power supply circuit 41 and the DC power supply circuit 36 are integrally mounted on the substrate 31 of FIG.

The high voltage power supply circuit 41 includes an oscillating unit 37, a switching unit 38, a boosting unit 39, and a rectifying unit 40. FIG. 3 shows an example of the specific circuit configuration.
The piezoelectric transformer 70 included in the booster 39 forms input-side terminals 72a and 73a and an output-side terminal 74a on the piezoelectric ceramic element plate 71, and converts a primary-side AC input voltage from the input-side terminals 72a and 73a into a piezoelectric transformer. Ceramic element plate 71
Is converted to a secondary-side AC voltage higher than the primary-side AC voltage via the mechanical vibration described above, and is output from the output-side terminal 74a to the ion generating electrode 27.

On the other hand, the rectifying section 40 includes the ion generating electrode 27.
This is for rectifying the secondary-side AC output of the piezoelectric transformer such that the polarity of the voltage applied to the piezoelectric transformer becomes dominant on the negative (first polarity) side. Thereby, the ion generating electrode 27 mainly functions as a negative ion generating source. On the other hand, the present invention can be configured to function as a positive ion generator,
In this case, the connection direction of the rectifier 40 may be reversed.

The oscillating section 37 receives the driving source DC from the DC power supply section 36 and generates an oscillating waveform at a frequency corresponding to the primary side AC input to the piezoelectric transformer 70. In this embodiment, the oscillating unit 37 is configured as a square wave oscillating circuit including an operational amplifier 62, a resistor 52 on the negative feedback side, and a capacitor 53. Note that the resistors 54 and 5
Reference numeral 5 designates the reference voltage of the oscillation input, that is, the center value of the oscillation voltage amplitude. Further, the capacitor 57 is for removing noise superimposed on the reference voltage, but can be omitted when the reference voltage is stable.

The switching section (switching circuit) 38 receives the waveform signal from the oscillating section 37 and performs high-speed switching of the DC constant voltage input from the power supply unit 30 to thereby input the piezoelectric transformer 70 to the primary side. Generate an AC waveform. Specifically, the switching unit 38
Is configured as a push-pull switching circuit including a pair of transistors 65 and 66. These transistors 65 and 66 are turned on / off by the output of the operational amplifier 62 (43 is a pull-up resistor), and the oscillation unit 37
A square wave AC waveform oscillating at the oscillation frequency of is generated. This waveform is input to the primary side of the piezoelectric transformer 70. Note that the capacitor 58 includes transistors 65 and 66
This is for removing noise superimposed on the switching input, but can be omitted when the noise is small.

Next, the piezoelectric ceramic element plate 71 of the piezoelectric transformer 70 is formed in a horizontally long plate shape, and a first plate-like region 7 polarized in the plate thickness direction is provided at an intermediate position in the plate surface longitudinal direction.
1a and a second plate-like region 7 polarized in the longitudinal direction of the plate surface
1b. Then, the first plate-shaped region 71a
Are formed so as to cover both surfaces of the input terminal 72a and the input terminal 72a connected to the input terminal 72a. On the other hand, the output terminal 74 is provided on the end surface of the second plate-like region 71b in the longitudinal direction of the plate surface.
An output-side electrode 74 to which a is connected is formed.

In the piezoelectric transformer 70 having the above configuration, when an AC input is made to the first plate-shaped region 71a through the input-side electrode pairs 72 and 73, the polarization direction of the first plate-shaped region 71a is changed in the thickness direction. Therefore, the plate wave propagating in the longitudinal direction is strongly coupled to the electric field in the plate thickness direction, and most of the electric energy is converted into the energy of the plate wave propagating in the longitudinal direction. On the other hand, this longitudinal plate wave is generated in the second plate-like region 7.
Although transmitted to 1b, since the polarization direction is the longitudinal direction, the plate wave is strongly coupled to the electric field in the longitudinal direction. And
When the input-side AC frequency corresponds to (preferably coincides with) the resonance frequency of the mechanical vibration of the piezoelectric ceramic element plate 71, the impedance of the element 71 is substantially minimum (resonance) on the input side, whereas it is substantially the same on the output side. Maximum (anti-resonance)
Then, the primary side input is boosted by the boosting ratio according to the impedance conversion ratio to become the secondary side output.

The piezoelectric transformer 70 having such an operation principle has a simple structure, and as described above, has an advantage that it can be configured to be extremely lightweight and compact as compared with a wire wound transformer having an iron core. Then, under a heavy load condition, the impedance conversion efficiency is high, and a stable and high boosting ratio can be obtained. In addition, in an ion generator driven under conditions close to the load release except for the generation of a discharge current due to ion emission, a high voltage suitable for ion generation can be stably generated. Can also be used effectively.

The material of the piezoelectric ceramic element 71 is not particularly limited. For example, in this embodiment, a lead zirconate titanate-based perovskite piezoelectric ceramic (so-called PZT) is used.
It consists of. This is mainly composed of a solid solution of lead zirconate and lead titanate, and can be suitably used in the present invention because of its excellent impedance conversion efficiency. The mixing ratio of lead zirconate and lead titanate is as follows:
0.8 to 1.3 in a lead zirconate / lead titanate molar ratio.
It is desirable that the degree be about the same in order to realize good impedance conversion efficiency. If necessary, a part of zirconium or titanium may be replaced with Ni, Nb, Mg, Co, M
It can be replaced by n or the like.

The PZT piezoelectric ceramic element is
When the driving frequency becomes extremely high, the resonance sharpness rapidly becomes dull and the conversion efficiency is lowered. Therefore, the frequency of the primary side AC input is 40 to 300 kHz (preferably 50 to 300 kHz).
It is desirable to set a value corresponding to the mechanical resonance frequency of the element 71 in a relatively low frequency range of about 150 kHz). Conversely, it is desirable to determine the dimensions of the element 71 such that the mechanical resonance frequency of the element 71 falls within the above frequency range.

When a PZT type piezoelectric ceramic element is used, the voltage level of the primary side AC input is set to about 15 to 40 V from the viewpoint of securing the generation efficiency of negative ions and ensuring the durability of the element. Is set. Thereby, the applied voltage level to the ion generating electrode 7 can secure about 4000 to 6000 V at the maximum in the frequency range of the primary side AC input.

Next, the rectifying section 40 includes a diode 76 forming a rectifying circuit. This diode 76 has a role of rectifying the secondary-side AC output of the piezoelectric transformer 70 so as to allow the charge transfer in the direction of charging up the ion generating electrode 27 to the negative polarity and prevent the charge transfer in the opposite direction. Fulfill. In the present embodiment, a plurality of (here, four) diodes 76 are connected in series in order to ensure a withstand voltage. Further, the ion generating electrode 27 is connected to an AC high voltage power supply, that is, the output terminal 74a of the piezoelectric transformer 70, and a discharge path 90 is provided branching from a path from the output terminal to the ion generating electrode. The end of the discharge path 90 is grounded.

FIG. 6A shows an example of the component mounting layout on the front side of the substrate 31, and FIG. The reference numerals in the drawings correspond to the reference numerals in the circuit diagrams of FIGS. In this embodiment, as shown in (a), a piezoelectric transformer 70 is provided on a substrate 31 and a piezoelectric ceramic element plate 7 is provided.
1 and the board surface are substantially parallel to each other. Further, as shown in (b), a region corresponding to the piezoelectric ceramic element plate 73 on the back side of the substrate 31 is covered with a metal film electrode 75, and the metal film electrode 75 and the piezoelectric ceramic element plate 71 are , And the portion of the substrate 31 located therebetween, constitutes a feedback capacitance.

FIG. 4 is a circuit diagram showing a configuration example of the DC power supply circuit 36. In this circuit, a DC voltage in a certain range (in this embodiment, DC 4.5 V to DC 32
V) can be continuously and continuously input from a single input connector 2 provided on the substrate, and generates a direct current boosted from the input voltage, and converts this to a drive source direct current (DC 32 V in this embodiment). And is configured as an input variable step-up circuit that outputs a signal. As already described, when incorporating ion generators in the form of modules for general home appliances such as air conditioners and various applications such as automobiles,
The voltage that can be used as the external DC varies depending on the product to be incorporated (for example, the former is DC5V,
The latter is DC12V or 24V). However, if the DC power supply circuit 36 is configured as the above-described variable input type step-up circuit, a constant drive source DC can always be obtained regardless of the external DC voltage used. Further, these external direct currents may be input from a single input connector 2, and there is no need to use different connectors depending on the voltage, so that the versatility can be further enhanced.

Further, a great feature of the above configuration is that, even when the input external DC voltage level fluctuates somewhat or a relatively large ripple is formed, the input is of a variable input type. That is, it can be converted into a constant-voltage drive source DC with almost no influence. This advantageously acts as a drive source direct current of the piezoelectric transformer which is easily affected by voltage fluctuations. Furthermore, as a result, it is not necessary to particularly provide a circuit for stabilizing the voltage in the preceding stage of the present step-up circuit, so that the power supply circuit can be greatly simplified. The above effects are particularly remarkably achieved in an automotive application in which ripples become particularly large as a result of the alternator AC waveform being superimposed on the vehicle battery voltage.

Hereinafter, the detailed configuration of the variable input type step-up circuit of FIG. 4 will be further described. The circuit includes a control IC 21 (in this embodiment, a commercially available product (NJM2360A) manufactured by New Japan Radio Co., Ltd.) and an inductor 10 externally connected to the control IC 21 (in this embodiment, And a diode 13 and a capacitor 16 serving as a rectifying / smoothing unit. The equivalent circuit of the control IC 21 is as shown in FIG. 5. The oscillation circuit 103 and a switching unit that branches a part of the external DC and inputs the branch DC input at a constant frequency defined by the oscillation circuit 103. 10
6 and a control unit 107 that compares the output DC voltage with the reference voltage and controls the permission and prohibition of the intermittent switching of the branch input DC so that the difference between the output DC voltage and the reference voltage is reduced. Have. Each terminal number in FIG. 5 corresponds to the terminal number in FIG.

As shown in FIG. 4, the inductor 10 generates an induced current based on the intermittent switching of the branch DC input, and outputs the ripple voltage based on the induced current superimposed on the external DC input voltage. Is what you do. Also, the rectifying / smoothing units 13 and 16 rectify and smooth the output voltage from the inductor 10 to generate a DC boosted from an external DC, and output this as a drive source DC (DC 32 V). belongs to.

The operation of this circuit is basically based on the control I
In C21, a current that is intermittently switched at a constant frequency is guided to the inductor 10, and a voltage waveform due to the induced current is superimposed on the input voltage, and then smoothing is performed.
It is based on the same principle as a general step-up circuit that generates a DC voltage higher than the input voltage. And
The feature is that the output voltage is fed back to the control IC 21 (terminal 5), and this is compared with the reference voltage in the control unit 107. If the output voltage overshoots the reference voltage, an induced current is generated. Is temporarily stopped so that the voltage is restored to the reference voltage. The voltage component due to the induced current of the inductor 10 is an AC waveform, and the voltage level when this is rectified and smoothed becomes the maximum value of the voltage increment due to the step-up. Therefore, if the switching frequency is set so as to be larger than the difference between the average level of the input voltage and the target voltage of the drive source DC to be obtained, the difference between the input voltage and the target voltage is any value. However, by adjusting the time ratio of stop / continuation of the switching operation, an output close to the target voltage can always be obtained. This means that the input voltage is continuously variable within a specified range (4.5 to 32 VDC in the present embodiment), and it is possible to absorb all the effects of voltage fluctuations due to sudden factors and ripples on the input side. means.

In this embodiment, the external direct current is supplied to the control IC
The short-circuit path 25 short-circuits the emitter terminals (second terminals) and the collector terminals (first terminals) of the transistors 106 a and 106 b forming the switching units incorporated in the circuit 21, and the inductor 10 is placed on the short-circuit path 25. Are located. Thus, a circuit configuration for superimposing a ripple voltage based on an induction current of the inductor 10 on an external DC input voltage can be rationally realized.

In FIG. 4, the external direct current is
Is entered from The DC voltage input from the first terminal of the connector 2 is input to the short-circuit path 25 via the adjusting resistor 8, and is output via the diode 13 forming a rectifying / smoothing circuit. This diode also serves to cut off the flyback current towards inductor 10 when switching is turned off. On the other hand, a capacitor 16 having a smoothing function is connected in parallel with this output path. The second and third terminals of the connector 2 are jumpers 7
(Connected state) is connected to the ground wire short-circuited. Reference numerals 9 and 10 denote ferrite cores forming a radio wave absorber. The capacitors 19, 20, and 22 appearing in the circuit of FIG. 4 are for absorbing noise. Further, reference numeral 3 denotes a varistor for surge suppression, and reference numeral 4 denotes a fuse for preventing overcurrent.

The feedback of the output voltage is divided and adjusted by the resistors 14 and 15 and input to the control IC 21. As shown in FIG. 4, the control circuit 107 includes a comparator 102, an AND gate 104, and an RS latch 105.
It is distributed to the reset terminal of the latch 105. Also,
The output of the comparator 102 is input to the other terminal of the AND gate 104. The fed back output voltage V is input from the fifth terminal to the comparator 102, where it is compared with the reference voltage Vr from the reference voltage generator 101. On the other hand, the output of the AND gate 104 is
5 is input to the reset terminal of the RS latch 105 while the output of the oscillator 103 is inverted. Therefore, when V <Vr, the RS latch 105 outputs a pulse synchronized with the oscillator 103, and switches the transistors 106a and 106b in synchronization with the pulse waveform. On the other hand, when V ≧ Vr, the RS latch 105 shuts off the output of the oscillator 103, and the switching stops. Note that the transistors 106a and 106b
In order to secure a switching current capacity, a two-stage Darlington connection is used. The oscillation frequency of the oscillator 103 is adjusted by the capacity of a capacitor (timing capacitor: 18 in FIG. 4) connected to the third terminal.

In the present embodiment, as shown in FIG. 4, a part of the output from the DC power supply circuit 36 is supplied to an external circuit other than the high-voltage power supply circuit 41 (FIG. 2). The connector 23 is provided on the board 31.
In this way, the DC power supply circuit 36 can be used as a power supply unit other than the high-voltage power supply circuit 41. For example, it can be used as a power supply system having the same voltage specification as that of the high-voltage power supply circuit 41 for peripheral circuits of the ion generator, and the use of such a power supply circuit further downsizes the entire apparatus. be able to. In the present embodiment, as shown in FIG.
3 is a polymer material molded part 3 together with the input connector 2
It is arranged so that the insertion port is exposed on the upper surface of the “0”.

A cleaning mechanism for cleaning, for example, the ion generating electrode 27 (FIG. 1) attached to the electrode connecting portion 27a can be connected to such an external output connector 2. If the ion generator has been used for a long period of time, dust, oil, or other contaminants contained in the airflow will adhere to the ion generation electrode, and the discharge surface will eventually be covered with those contaminants. . In such a state, discharge for ion generation is significantly hindered, which may lead to a decrease in ion generation efficiency or, in extreme cases, stop of ion generation. Therefore, if such a cleaning mechanism is provided, the ion generating electrode 2
7 can always be kept in a normal state, and the ion generation efficiency can be increased.

The cleaning mechanism may be an electric cleaning mechanism for burning off dirt attached to the ion generating electrode by electric heating. The electrical cleaning mechanism may be, for example, the ion generating electrode itself or a separate resistive heating element disposed in the vicinity of the ion generation to be burned out by causing resistance heating to generate heat. Something like that has been adopted. That is, in the electrical cleaning mechanism 79, as shown in FIG. 9A, a high-voltage power supply unit is also used as a high-voltage generation unit for spark discharge, and a high-voltage power supply unit is provided between the ion generation electrode 27 and the spark discharge counter electrode 83. Is applied with a high voltage for spark discharge. Then, by the discharge spark generated between the ion generation electrode 7 and the spark discharge counter electrode 83 by the application of the high voltage, the deposits attached to the ion generation electrode are burned out and removed. The spark discharge counter electrode 83 can be grounded. However, if the spark discharge time is short, the discharge current can be absorbed by the device capacitance.

The spark discharge counter electrode 83 is the ion generating electrode 2
7 are arranged so as to face the tip 7a. Specifically, the spark discharge opposing electrode 83 is formed in a rod shape, and the distal end surface or side surface (the side surface in the present embodiment) of the rod-shaped spark discharge opposing electrode 83 faces the distal end portion 7a of the ion generating electrode 27.

As shown in FIG. 8, the spark discharge opposing electrode 83 is connected to the ion generating electrode 7 with respect to the ion generating electrode 7.
At least a relative position ((a)) between a separation position ((b)) for generating ions from the electrode and an approach position ((a)) for generating a discharge spark between the spark discharge counter electrode 83 and the ion generation electrode 7. A spark discharge opposing electrode moving mechanism 78 is provided for moving toward and away from each other. Here, the position of the ion generation electrode 7 is fixed, and the spark discharge counter electrode moving mechanism 7
Reference numeral 8 is configured to move the spark discharge counter electrode 83.

Specifically, the spark discharge counter electrode moving mechanism 7
Numeral 8 includes a solenoid 80, and a rod-shaped spark discharge counter electrode 83 is provided at the tip end of a forward / backward rod 81 via a coupling member 82.
When the forward / backward rod 81 is driven forward / backward by the solenoid 80, the front end of the spark discharge opposing electrode 83 approaches or separates toward the front end of the ion generating electrode 7. Reference numeral 84a is a positioning plate for fixing the solenoid 80. Reference numeral 84 denotes a guide plate having a guide hole through which the spark discharge opposing electrode 83 is inserted. Since the spark discharge opposing electrode 83 approaches and separates substantially horizontally toward the ion generating electrode 7, a gap for spark discharge is formed. Accuracy can be increased.

FIG. 7 is a circuit diagram showing an example of the electrical configuration of the spark discharge counter electrode moving mechanism 78. Solenoid 80
Receives power from the DC power supply unit 36 in FIG. 2 by connecting the connector 87 to the external input connector 2 (D
C32V). On the other hand, the energizing signal of the solenoid 80 is supplied from the control unit 86 via a switch mechanism 85 (in the present embodiment, constituted by a photo MOS). Control unit 8
6 is an input / output port 86a and a CPU connected to the input / output port 86a.
The operation control program for the spark discharge counter electrode moving mechanism 78 is written in the ROM 86d. The CPU 86b functions as an operation control subject of the discharge counter electrode moving mechanism 78 by executing the operation control program using the RAM 86c as a work area. When the control unit 86 issues a drive command signal for the spark discharge opposing electrode moving mechanism 78, the photo MOS 85 is turned on, and the solenoid 80 receives a DC drive voltage and is energized.

As shown in FIG. 9 (a), the spark discharge opposing electrode 83 is
Approach towards 7. Thereby, as shown in FIG. 3B, the tip 83a of the spark discharge opposing electrode 83 is positioned with respect to the tip 7a of the ion generating electrode 27 so as to form a predetermined gap. For example, by applying a discharge voltage to the ion generating electrode 7 in this state,
Discharge sparks SP are generated in the gaps, and attached matter such as dust and dirt attached to the tip 7a of the ion generating electrode 7 is burned off by heat concentration due to the sparks. On the other hand, as shown in FIG. 3C, if the spark discharge opposing electrode 83 recedes, the distance between the electrodes increases, and the generation of the discharge spark stops. However, the ion generating electrode 27 continues to be the ion generating electrode 27.
Since the voltage for ion generation is applied to the battery, it is possible to immediately shift to the ion generation mode as soon as the spark discharge ends.

Returning to FIG. 4, in the circuit module of the present invention, the following contrivance has been made so that the circuit module can be commonly used for AC power supply input. That is, the full-wave rectifier circuit 5 including a diode bridge is provided in parallel with the DC input step-up circuit wiring section. At the time of AC use, the control IC 2 that constitutes the step-up circuit
Element 1 and its peripheral elements can be omitted. When an external AC power supply is used, the grounding system on the external AC power supply side is used, so that the ground wiring system on the circuit module side is not used. Therefore, the jumper 7 is cut and used. In the case where only the DC input is used, the circuit portion for sharing the AC input can be omitted.

In the circuit module 1 of the present invention, FIG.
The high-voltage power supply circuit 41 receives the supply of a constant DC voltage from the DC power supply unit 36, and generates a square wave AC by the operation of the oscillation unit 37 and the switching unit 38, which is applied to the input terminal 72a of the piezoelectric transformer 70 for adjustment. The signal is input as a primary-side AC input via a resistor 67 (including a variable resistor 67a for waveform adjustment). The piezoelectric transformer 70 boosts the voltage in accordance with the operation principle described above and outputs the boosted voltage from the output terminal 74a as a secondary AC output.

In the above configuration, as shown in FIG. 5A, when the secondary side of the piezoelectric transformer 70 outputs a negative half-wave, the ion generating electrode 27 is negatively charged. as a result,
An electric field gradient suitable for generating negative ions is generated around the ion generation electrode 27, and molecules in the surrounding air, for example, water molecules are ionized in the form of hydroxyl ions or the like. That is, negative ions are generated. Next, when a positive half-wave is output, the negative charge of the ion generating electrode 27 tends to be discharged to the ground side, but the flow of this charge is blocked by the diode 76. Thus, the negatively charged state of the ion generating electrode 27 is always maintained, and negative ions can be constantly generated.

[0056]

EXAMPLES The results of experiments conducted to confirm the effects of the present invention will be described below. (Example 1) It was confirmed by the following experiment that the maximum voltage applied to the ion generating electrode 27 was affected by the selection of the material of the polymer material mold portion 30. That is,
The ion generator 1 shown in FIG. 1 and FIG.
Having the following circuit configuration. As the composition of the piezoelectric ceramic element 71, a composition in which lead zirconate and lead titanate are mixed at a molar ratio of about 1: 1, and containing about 2% by weight of Nb as an additional element, for example, having a length of 52 mm,
It was formed to have dimensions of 1.85 mm in width and 13 mm in thickness. Further, the ion generating electrode 7 was formed of a Ni plate having a thickness of about 0.2 mm, and the discharge portion 7b was formed to be sharp with a length of about 5 mm. The circuit board 5a was made of a glass fiber reinforced plastic plate. Then, the following three types were formed by casting as the material of the polymer material mold part (is a comparative example). In addition, the hardness after casting is determined according to JIS: K-625.
3 (1997) using a type A durometer. Urethane rubber (hardness: 45) Silicone rubber (hardness: 60) Epoxy resin (hardness: 90 or more)

When the primary-side AC input to the piezoelectric transformer 70 was operated at a frequency of about 72 kHz and a voltage of 24 V at peak to peak, the voltage applied to the ion generating electrode 7 was determined using hard epoxy resin. Was 4
In the case of using a rubber having a hardness of 80 or less while staying at 600 V, 5200 V and 4
It was found that a higher voltage of 900 V could be generated.

(Embodiment 2) In the configuration of FIG.
The following experiment confirmed that the selection of the thickness of the polymer material coating portion 130 affected the maximum voltage applied to the ion generating electrode 27. That is, the ion generator 1 shown in FIGS. 1 and 2 was configured to have the circuit configuration shown in FIGS. The piezoelectric ceramic element 71, the ion generating electrode 7, and the circuit board 5a were configured in the same manner as in the first embodiment. A two-component acrylic urethane resin paint (trade name: Air Urethane (Isamu Co., Ltd.)) was used as the material of the polymer material coating portion, and the entire substrate including the piezoelectric ceramic element 70 was coated by spraying. The coating thickness t is
On the main surface of the piezoelectric ceramic element 70, two levels of 0.4 mm (example) and 2.0 mm (five coatings) were set.

When the frequency of the primary side AC input to the piezoelectric transformer 70 was set to about 72 kHz and the voltage was set to 24 V at peak to peak, the applied voltage level to the ion generating electrode 7 was 2 mm in coating thickness. The coating thickness was kept at 4700 V, whereas the coating thickness of 0.4 mm, which is 1 mm or less, was 5200 V.
V and higher voltage can be generated.

[Brief description of the drawings]

FIG. 1 is an external perspective view showing an example of a circuit module for an ion generator of the present invention, and a cross-sectional view showing the internal configuration thereof.

FIG. 2 is a block diagram showing a configuration of the ion generation circuit unit.

FIG. 3 is a circuit diagram showing an example of a high-voltage power supply unit of FIG. 2;

FIG. 4 is a circuit diagram showing an example of a DC power supply unit.

FIG. 5 is an equivalent circuit diagram of the control IC of FIG. 4;

FIG. 6 is a view showing an example of a board mounting layout of the ion generation circuit unit of FIG. 1;

FIG. 7 is a circuit diagram illustrating an example of an electrical configuration of a cleaning mechanism.

FIG. 8 is an explanatory view showing an example of a spark discharge type cleaning mechanism together with its operation.

FIG. 9 is a diagram illustrating the operation of the cleaning mechanism of FIG. 8;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Circuit module for ion generator 2 Connector for external direct current extraction 10 Inductor 13 Diode 16 Capacitor (rectifying / smoothing part) 21 Control IC 23 Input connector 25 Short circuit path 27 Ion generating electrode 27a Electrode connection part 30 Polymer material molding part 31 Substrate 36 DC power supply circuit and 41 High voltage power supply circuit 70 Piezoelectric transformer 78 Cleaning mechanism 103 Oscillation circuit 106 Switching unit 106a, 106b Transistor 107 Control unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4C080 AA09 BB02 BB05 CC01 QQ11 4D054 AA11 BB04 CA18 CA19 CB01 CB03 CB07 CB09 CB10 DA12 EA01 5H730 AA15 AS04 BB57 BB61 DD02 DD28 EE48 FD01 XX XX XX XXXXX ZZ01 ZZ04 ZZ11 ZZ12 ZZ15 ZZ19

Claims (10)

[Claims] 1. An electrode connecting part for connecting an ion generating electrode, a high-voltage piezoelectric transformer for supplying a high voltage for ion generation to the electrode connecting part, and a piezoelectric transformer for the same A high-voltage power supply circuit configured to include a driving DC-AC conversion circuit that generates a primary-side driving AC from a DC of a predetermined voltage (hereinafter, referred to as a driving source DC); A DC power supply circuit that converts the input external DC to the drive source DC of a predetermined constant voltage, irrespective of the input voltage, A circuit module for an ion generator, comprising: a substrate on which a high-voltage power supply circuit and a DC power supply circuit are integrally mounted. 2. The DC power supply circuit is capable of continuously inputting a DC voltage in a certain range from a single input connector provided on the board, and generates a DC voltage higher than the input voltage. 2. The circuit module for an ion generator according to claim 1, wherein the circuit module is configured as an input variable step-up circuit that outputs the output as the drive source DC. 3. An input variable type step-up circuit, comprising: an oscillating circuit; and a switching unit for branching and inputting a part of the external direct current and intermittently switching the branched direct current input at a constant frequency defined by the oscillating circuit. A control unit that controls the allowance and prohibition of the intermittent switching of the branch input DC so that the output side DC voltage is compared with the reference voltage and the difference between the output side DC voltage and the reference voltage is reduced. A control IC, which is externally connected to the control IC, generates an induced current based on the intermittent switching of the branch DC input, and superimposes a ripple voltage based on the induced current on the external DC input voltage. An inductor that is externally connected to the control IC, and rectifies and smoothes an output voltage from the inductor to thereby control the external direct current. 3. The circuit module for an ion generator according to claim 2, further comprising: a rectifying / smoothing unit for generating a direct current boosted from a current and outputting the generated direct current as the driving source direct current. 4. The external direct current is input to a short-circuit path for short-circuiting an emitter terminal and a collector terminal of a transistor constituting the switching unit incorporated in a control IC, and the inductor is arranged on the short-circuit path. The circuit module for an ion generator according to claim 3, wherein: 5. A part of an output from the DC power supply circuit,
For supplying to an external circuit other than the high-voltage power supply circuit,
The circuit module for an ion generator according to any one of claims 1 to 4, wherein an external output connector is provided on the substrate. 6. The circuit module for an ion generator according to claim 5, wherein a cleaning mechanism for cleaning an ion generating electrode attached to the electrode connection portion is connected to the external output connector. 7. A polymer material molding section for molding a piezoelectric ceramic element of the piezoelectric transformer together with components of the high-voltage power supply circuit and the DC power supply circuit on the substrate, wherein the polymer material molding section is provided. The ion generator according to any one of claims 1 to 6, comprising a rubber or an elastomer having a type A durometer hardness of 80 or less specified in JIS: K-6253 (1997). Circuit module for equipment. 8. A polymer material coating portion for coating a piezoelectric ceramic element included in the piezoelectric transformer on the substrate together with components of the high-voltage power supply circuit and the DC power supply circuit, wherein the polymer material mold portion is provided. The circuit module for an ion generator according to any one of claims 1 to 6, wherein the coating thickness of the piezoelectric ceramic element is 1 mm or less. 9. An electrode connecting portion for mounting an ion generating electrode, for supplying a high voltage for generating ions to the electrode connecting portion, and a step-up piezoelectric transformer; A high-voltage power supply circuit including a driving DC-AC conversion circuit that generates a primary-side driving AC from a DC of a predetermined voltage (hereinafter, referred to as a driving source DC); A high-voltage power supply circuit and a unit integrally mounted thereon, on the substrate, a high-voltage power supply circuit comprising a high-molecular material molded part, which molds a piezoelectric ceramic element of the piezoelectric transformer together with the components of the high-voltage power supply circuit, The polymer material mold part is JIS: K-6253
A circuit module for an ion generator, comprising a rubber or an elastomer having a hardness of 80 or less in a type A durometer hardness specified in (1997). 10. An electrode connecting portion for attaching an ion generating electrode, for supplying a high voltage for generating ions to the electrode connecting portion, and a step-up piezoelectric transformer; A high-voltage power supply circuit including a driving DC-AC conversion circuit that generates a primary-side driving AC from a DC of a predetermined voltage (hereinafter, referred to as a driving source DC); A substrate on which the unit and the high-voltage power supply circuit are integrally mounted, and a polymer material coating unit for coating the piezoelectric ceramic element of the piezoelectric transformer together with the components of the high-voltage power supply circuit on the substrate, A circuit module for an ion generator, wherein a coating thickness of the polymer material molded portion on the piezoelectric ceramic element is 1 mm or less. Yuru.