JPH0353879B2 - - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to an electric blower input control circuit in a vacuum cleaner.

Technical Background of the Invention Fig. 6 shows the external appearance of a conventional vacuum cleaner, in which there is a removable dust collection case 2 at the front of the main body case 1, and a hose insertion port 3 of the dust collection case 2 is connected to the main body case 1. Hose 4 is inserted. An operation switch section 6 is provided at the hose proximal section 5.

FIG. 5 shows the circuit configuration. Basically, an electric blower 8 and a bidirectional thyristor 9 are connected in series to a 100V AC power source 7 of AC 50/60Hz. A protective resistor R ₁ and a capacitor C ₁ are connected in parallel to this bidirectional thyristor 9 .
Further, on the gate side of the bidirectional thyristor 9, a gate trigger circuit 11 mainly consisting of a characteristic variable negative resistance element PUT10 and a capacitor _C2 is provided.
This PUT10 is a dividing resistor connected to the gate side
Characterized by R ₆ and R ₇ , when a voltage determined by these resistances R ₆ and R ₇ is applied to the anode side,
It is something that turns on. Therefore, the AC power source 7 is connected to both ends of the resistors R ₆ and R ₇ via a diode through the resistor R ₁₀ .
Full-wave rectification with a rectifier circuit 12 consisting of D ₃ to _{D 6} , and resistance
A constant voltage made constant by a Zener diode ZD is applied via _R9 . On the other hand, PUT1
A capacitor C ₂ is connected to the anode of 0. Further, the cathode side of PUT 10 is connected to the gate of thyristor 13 via resistors R ₄ and R ₅ . This thyristor 13 is connected to the rectifier circuit 12 together with a resistor _R3 . Diodes D ₁ and D ₂ are connected in parallel to the thyristor 13 and the resistor R ₃ , the midpoint of which is connected to the gate of the bidirectional thyristor 9 , and a resistor R ₂ is interposed between the thyristor 13 and the anode. ing.

Thus, the AC power source 7 is full-wave rectified by the rectifier circuit 12, and the voltage regulated by the Zener diode ZD charges the capacitor _C2 via the variable resistor _VR1 of the operation switch section 6. Therefore, when the charging voltage of this capacitor C ₂ reaches the voltage value determined by the resistors R ₆ and R ₇ , the PUT 10 is turned on. Therefore, if the variable resistor VR ₁ is variably operated, the charging cycle of the capacitor C ₂ changes according to the change in resistance, and the ON timing of the PUT 10 also changes. In any case, when PUT 10 turns on, the gate of thyristor 13 is triggered and turns on.
As a result, the anode of the thyristor 13 receives not only the rectified output from the rectifier circuit 12, but also the electric blower 8, the gate of the bidirectional thyristor 9, and the diode.
The current continues to flow through D ₁ , resistor R ₃ , thyristor 13 and diode D ₄ . This current continues to flow until the bidirectional thyristor 9 turns on and the voltage across its terminals drops, so even if the load is an inductive load such as the electric blower 8, the bidirectional thyristor 9
will definitely be triggered. Moreover, even after bidirectional thyristor 9 is turned on, thyristor 1
3 is a current that flows through the rectifier circuit 12 and maintains the ON state, so even if the bidirectional thyristor 9 is turned off due to vibration of the main current, it is turned on again. Even when the polarity of the AC power supply 7 is reversed, current similarly flows through the diode D ₃ , the thyristor 13 and the diode D ₂ .
Bidirectional thyristor 9 is turned on reliably.

In this way, the bidirectional thyristor 9 is controlled in accordance with the resistance change caused by the variable operation of the variable resistor VR ₁ , and the input to the electric blower 8 is controlled, and the electric blower 8 is turned off even at a low power factor. Never.

In the conventional system, a high-resistance resistor R ₁₁ is used to stop the electric shock in contrast to the variable resistor VR ₁ of the operation switch section 6.
R ₁₂ is interposed. For this reason, the variable resistor VR ₁
must also have high resistance (high impedance). The maximum and lowest resistance value of this variable resistor VR ₁ regulates the minimum input. In addition, in Figure 6,
SW indicates the OFF position of variable resistor VR ₁ ,
As a result, the electric blower 8 is stopped (it may be a separate ON/OFF switch).
However, variable resistors have variations due to mass production, and the deviation is 10 to 15% compared to fixed resistors.
It's about double that. For example, with a fixed resistor, a value of about ±2% can be easily obtained, but with a variable resistor, if the total resistance value exceeds 500KΩ, a deviation of about ±20 to 30% occurs. For this reason, even if the maximum resistance value of the variable resistor is set to 700KΩ for the minimum input setting, it will vary from 490 to 910KΩ due to variations.
If it becomes about 800 to 900KΩ, the electric blower 8 may stop even if it is not in the OFF position, and the minimum input cannot be set.

Therefore, there is a method of selectively using variable resistors to manage the total resistance value, but this method is expensive.

In order to eliminate these drawbacks, the applicant has proposed a control circuit as shown in FIG. In this case, the operation switch unit 6 is provided with a variable resistor VR ₁ , a fixed resistor R ₁₃ as a minimum input setting resistance, and a correction fixed resistor R ₁₄ . Here, in area A, the slider 14a is the common conductive pattern PC and the resistance pattern PR of variable resistor VR ₁ .
The resistance pattern PR has a resistance value that increases from the left side to the right side in the figure, and reaches the maximum resistance value at the right end. A conductive pattern PD ₁ for connecting the fixed resistor R ₁₃ is provided on the right side beyond the maximum resistance value of the resistance pattern PR. Therefore, the fixed resistor _R13 is connected in the B region where the slider 14a is connected to the common conductive pattern PC and the conductive pattern _PD1 , and the B region corresponds to the lowest input setting position. Then, a conductive pattern with a length corresponding to area A
PD ₂ is provided and connected to a fixed resistor R ₁₄ .
Therefore, the fixed resistor _R14 is connected in parallel with the variable resistor of the variable resistor _VR1 when the slider 14a is in the A region.

In such a configuration, when the electric blower 8 is set to the lowest input, the sliders 14a and 14b are positioned in the B region. As a result, a fixed resistor R ₁₃ is placed in series with the capacitor C ₂ regardless of the variable resistor VR ₁ , and based on the resistance value of this fixed resistor R ₁₃ , the bidirectional thyristor 9 and therefore the electric blower 8 are It will be controlled by the input. In this way, the minimum input setting is performed by the fixed resistor _R13 , and the fixed resistor has a variation width of 1/10 or less of the maximum resistance value of the variable resistor, for example, ±2 with a carbon film.
%, and metal film types with a tolerance of around ±0.2% can be easily mass-produced, making it possible to keep the minimum input variation extremely small and stable.

On the other hand, when the input setting is higher than the minimum input, slider 1
By slidingly displacing 4a and 14b into the A region, the resistance of the variable resistor VR ₁ is appropriately varied, and the input to the electric blower 8 is controlled in accordance with this resistance change. Here, fixed resistor R ₁₄ is variable resistor
A resistor with a resistance lower than the maximum resistance value of VR ₁ and with a small tolerance is used to correct variations in the variable resistor VR ₁ , especially variations in the maximum resistance value. For example, variable resistor VR ₁ is ±30
% tolerance width, and the tolerance width of fixed resistor _R14 is ±2%.
And 1/3 of the maximum resistance value of variable resistor VR ₁
If the resistance value is set to about 10, the variation can be reduced to around ±10. More specifically, for example, if the maximum resistance value of variable resistor VR ₁ is 2MΩ, fixed resistor R ₁₄ =
Assuming 700KΩ, the variation of variable resistor VR ₁ is 1.4 to 2.6MΩ, and the variation of fixed resistor R ₁₄ is
It is 686 to 714KΩ. As a result, the combined resistance of both has a variation of about 470 to 560KΩ with respect to the ideal value of about 518KΩ, and the variation can be suppressed to ±10% or less. This allows, for example, a fixed resistance R ₁₃ =
If it is assumed to be 700KΩ, with only variable resistor VR ₁ , the maximum resistance value will be 700KΩ due to the large variation.
However, the fixed resistor _R14 corrects the variation so that it will not overlap with the lowest input.

Then, when stopping the electric blower 8, the switch 18 is turned OFF.

Here, if we look at the structure of the variable resistor VR ₁ etc., it is constructed as a variable resistor 15 as shown in FIG. That is, a resistance pattern is formed on the surface of the substrate 16.
PR and conductive patterns PD ₁ and PD ₂ are formed (see Fig. 9), and a common conductive pattern PC is formed on the back side (see Fig. 10), and the slider 14a is formed with the resistive pattern PR. Contact and common conductive pattern sliding on line with conductive pattern PD ₁
It has contacts that slide on the PC line. In addition, the slider 14b is a contact that slides on the line of conductive pattern PD ₂ and a common conductive pattern PC.
It has a contact point that slides on the line. These contact points are on the same line in the width direction of the substrate 16, and the sliders 14a and 14b are set to operate in conjunction with each other in the sliding direction by the knob 17, and the dimension l is their maximum stroke. This knob 17 and the switch 18 are arranged at the hose proximal portion 5, as shown in FIG.

Problems with the Background Art When considering actual cleaning, cleaning is performed under a certain input setting state, but in areas with a lot of dirt, there are times when it is desired to perform powerful cleaning in spots. In such a case, you can increase the input by operating the knob 17, but after spot cleaning, you have to operate the knob 17 to reset to the original input state. is troublesome,
Cleaning cannot be done efficiently.

Purpose of the Invention The present invention was made in view of the above points, and it is possible to ensure the maximum input state at any time without changing any variable resistance value set in the variable resistance section, and it is possible to maintain the maximum input state at any time. The purpose of this invention is to obtain an electric blower input control circuit that can improve the efficiency of the electric blower.

SUMMARY OF THE INVENTION The present invention connects an electric blower and a bidirectional thyristor in series to an AC power supply, and includes a manually operated variable resistance section at the proximal end of a hose, and a first switch that opens and closes a circuit of the variable resistance section. In the electric blower input control circuit, the electric blower input control circuit is configured to adjust the input of the electric blower by controlling the bidirectional thyristor according to a change in the resistance of the variable resistance section, the variable resistance section being provided at a proximal portion of the hose. A second switch is provided to short-circuit and switch to the maximum input setting value side. Therefore, in a normal place, the input of the electric blower can be adjusted by changing the resistance of the variable resistor, and in a place with a lot of dirt, the maximum input can be selected using the second switch to perform powerful spot cleaning. It is designed so that it can be done easily.

Embodiment of the Invention A first embodiment of the invention will be described based on FIGS. 1 to 3. Components that are the same as those shown in FIGS. 5 to 11 are indicated using the same reference numerals. In this embodiment, a switch 18 is used as a first switch, and a second switch 19 is provided in the hose proximal portion 5 separately from this switch. This second switch 19
As shown in Figure 1, has contacts a, b and common contact c. When contact a is selected, it is connected to the variable resistor VR ₁ side as usual, and when contact b is selected, it is connected to the maximum input. The variable resistance circuit is shorted so that

Here, regarding the structure of the second switch 19, the second
This will be explained with reference to the drawings and FIG. Second switch 19
is operated by a touch plate 20 at the hose proximal portion 5, and this touch plate 20
is a spring 22 rotatably provided around a fulcrum 21;
is biased upward with a light force. However, the second switch 19 is turned on and off consciously, and the spring 22 for the touch plate 20 has a strong spring force to the extent that the user does not feel strange when gripping the touch plate 20. has been done. Here, the switch structure has 1 circuit and 2
This is a contact switch, and contact plates 23a and 23b corresponding to contacts a and b are provided vertically to face each other, and a contact plate 23c corresponding to common contact c is disposed between them and is attached to the touch plate 20. .

In such a configuration, when cleaning is to be performed, the user turns on the switch 18, sets the appropriate input by operating the knob 17, and grips the hose proximal portion 5. At this time, touch plate 20
However, with normal weak gripping, the contact plates 23b and 23c will not come into contact with each other. Therefore, in FIG. 1, the contacts a and c are in a connected state, and cleaning is performed under an input control state according to the variable resistance value arbitrarily set in the variable resistor _VR1 .

Let us now consider the case where a heavily soiled area is to be cleaned during cleaning. At this time, the touch plate 20 may be gripped firmly at the hose proximal portion. That is, when the touch plate 20 is pushed, the touch plate 20 descends against the spring 22, and the contact plates 23b and 23c come into contact with each other. As a result, contacts b and c in FIG.
is in a connected state, and is driven with the maximum input that can be set with this variable resistance circuit, regardless of the setting value of variable resistance _VR1 . This makes it possible to spot-clean areas with a lot of dirt using the maximum input, and after spot-cleaning, weaken the gripping force and return the second switch 19 to the a contact side.
Cleaning can be restarted with the original settings input.

As described above, according to the present embodiment, the set input state can be changed by simply controlling the second switch 19 by adjusting the gripping force of the hose proximal portion 5 on the touch plate 20 depending on the cleaning situation. It is possible to arbitrarily secure the maximum input state and the maximum input state, and it is possible to carry out spotty and powerful cleaning in areas with a lot of dirt without changing the variable resistor, thereby improving cleaning efficiency.

Next, a second embodiment of the present invention will be described with reference to FIG. In this embodiment, the contact a of the second switch 19 is provided floating, and the first switch 18 and the variable resistor VR ₁ are connected to the second switch 19.
The circuits are arranged in parallel.

In such a configuration, switch 18 is turned on.
If you operate it in this state, cleaning will be performed in the input state set by the variable resistor _VR1 . and,
If the gripping force of the hose proximal portion 5 to the touch plate 20 is strengthened and the second switch 19 is switched to the contact point b side, regardless of the value set by the variable resistor VR ₁ ,
Powerful cleaning is possible at the maximum input state that can be set with this variable resistor VR ₁ . In this way, it is possible to freely switch between the setting input and the maximum input.

By the way, in this embodiment, the switch 18
It is also possible to use it while it is turned off. That is, if the second switch 19 is on the contact a side, the vacuum cleaner will be in a stopped state, but if the touch plate 20 is held and the second switch 19 is switched to the contact b side, the vacuum cleaner will be driven in the maximum input state. I can do it. In other words, it is possible to freely switch between the stopped state and the maximum input state. According to this, for example, when moving a dresser or the like, it is brought to a halt state, and when cleaning dust at the back of the dresser, it is possible to powerfully clean with maximum input.

Note that the first switch 18 referred to in the present invention may be an integral switch that operates in conjunction with the variable resistor _VR1 .

Effects of the Invention As described above, the present invention connects an electric blower and a bidirectional thyristor in series to an AC power supply, and connects a manually operated variable resistance section to the hose proximal portion and opens/closes the circuit of this variable resistance section. In the electric blower input control circuit, the electric blower input control circuit is provided with a first switch that controls the input of the electric blower by controlling the bidirectional thyristor according to a change in resistance of the variable resistance section. Since a second switch is provided to short-circuit the variable resistor and switch to the maximum input setting value, the input of the electric blower can be adjusted by changing the resistance of the variable resistor in normal locations, and can be used in dirty locations. This has the effect that it is easy to select the maximum input using the second switch and perform powerful spot cleaning.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing a first embodiment of the present invention,
Fig. 2 is an external perspective view showing the structure near the hose proximal portion, Fig. 3 is a cross-sectional view of a part thereof, Fig. 4 is a circuit diagram showing a second embodiment of the present invention, and Fig. 5 is a conventional example. FIG. 6 is a circuit diagram, and FIGS. 7 to 11 show the contents of the applicant's previous proposal.
FIG. 7 is a circuit diagram, FIGS. 8 and 9 are a plan view, FIG. 10 is a bottom view, and FIG. 11 is an external perspective view. 5... Hose proximal part, 7... AC power supply, 8... Electric blower, 9... Bidirectional thyristor, 18... First switch, 19... Second switch, VR ₁ ... Variable resistor.

Claims (1)

[Claims] 1. An electric blower and a bidirectional thyristor are connected in series to an AC power source, and a manually operated variable resistance section and a first switch for opening and closing the circuit of this variable resistance section are provided at the hose end, and the variable resistance section is In the electric blower input control circuit, the input of the electric blower is adjusted by controlling the bidirectional thyristor according to a change in the resistance of the resistance section, the variable resistance section is short-circuited to the hose proximal section, and the maximum input is adjusted. An electric blower input control circuit characterized by being provided with a second switch that switches to the set value side.