JPH0785375B2 - Automatic door control device - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to an automatic door control device.

(Technical background and problems to be solved) Conventionally, as shown in FIG. 5, a sensing unit (sensing plates 101, 102)
In an automatic door control device that is driven separately by the oscillator of the control unit 103, the control unit 103 is pulled by a feeder 104 such as a coaxial cable to the door 105 and the wire is pulled in a blind manner. However, the length of the feeder 104 becomes a problem due to the structure of the building. That is, since the circuit system is adjusted with the length of the feeder 104 kept constant at the time of manufacture, the length could not be changed by cutting the feeder 4 at the actual installation site. If the feeder is cut at the installation site, the length of the cable will change and the parameters used during adjustment will change, and reliable door opening and closing operations cannot be performed.Therefore, it is necessary to adjust the circuit system on site each time. there were. Here, there has been a problem that such adjustment work is difficult unless there is some electrical knowledge, and the work is extremely complicated due to the environment of the installation place. Even if it is not, if the sensing plate is buried in the ground, there is a disadvantage that the same adjustment as above is required due to the influence of the mortar and the like around it.

That is, in this type of door control device, the pair of sensing plates 101 and 102 are regarded as capacitors to form a bridge circuit, and the capacitance of a variable capacitor forming one side of the bridge circuit is adjusted to achieve an electrical balance. Taking advantage of the fact that the capacitance between the sensing plates 101 and 102 changes when a person approaches the sensing unit, a signal when the balance is lost is taken out and a switching operation is performed to open and close the door 105. . However, when the length of the feeder is changed or the environment is changed, the capacity of the built-in variable capacitor must be readjusted, and the adjustment work is extremely complicated. Also, the sensing plate
101 and 102 and the feeder 104 are tuned by a capacitor as a part of the resonator, and when a person approaches the sensing unit, it is detected that the Q and frequency of the tuning circuit of the oscillator change, and the opening and closing of the door is controlled. There are also things. However,
Even in this control device, the length of the feeder changes,
If the environment changes, the capacitance of the capacitor incorporated in a part of the resonator must be readjusted.

As a solution to such a drawback, there is Japanese Patent Application No. 60-204335 by the present applicant. This is shown in FIG. 6, and an impedance converter 3 and an in-phase current blocking choke coil 4 are provided between the two embedded sensing plates 1 and 2 forming the sensing portion 5 and the oscillating portion 20. And a feeder 10 such as a coaxial cable are connected in series. An oscillating section 20 is connected to an automatic reset type DC amplifier 30 as disclosed in Japanese Patent Publication No. 60-34293, for detecting changes in the capacitance and Q of the sensing plates 1 and 2, that is, the proximity or separation of the human body. Then, the door open / close signal DRC is output.

Here, the choke coil 4 has the same characteristic impedance line as the feeder 10, the two sensing plates 1 and 2 are equivalent to capacitors, and the oscillating unit 20 connects the resonance coil and the resonance capacitor in series. Since it has, the sensing system of FIG. 6 becomes as shown in FIG. The feeder of FIG. 7 (hereinafter,
When a coaxial cable and) at the inlet of 10 examine the relationship between the impedance Z _a for line length l, it is as indicated by a solid line in FIG. 8, a solid line capacitive load, the characteristic impedance Z ₀ = X _c
In the case of, the phase due to reflection is delayed by λ / 8 from the open characteristic. Therefore, capacitors (sensing plates 1 and 2)
Depending on the capacity of, the characteristic is located between the short circuit and the open circuit. For convenience of explanation, assuming that the capacitor capacitance C _c is exactly the value of Z ₀ = X _c , the solid line characteristics shown in FIG. 8 are obtained, so the series resonance frequency is λ / 8 and the parallel resonance frequency is 3/8 · λ. . Since parallel resonance is good when used as a human body sensor for an automatic door, if the length l of the coaxial cable 10 is determined, the parallel resonance frequency f _{01 of} this circuit system is determined. At this frequency, the oscillating frequency f ₀ of the oscillating unit 20 is equal to the above-mentioned frequency f ₀ of the sensing unit 5.
_The effect of the proximity of the sensing unit 5 to the human body, that is, the shift of the frequency f ₀₁ or the decrease of Q is given to the oscillating unit 20 by the capacitor couple or the inductive couple shown in FIG. At 20, a change occurs in the oscillation output, and this change is detected by the automatic recovery type DC amplifier 30.

By the way, the in-phase current blocking choke coil 4 shown in FIG.
7 is included in the sensing part as a part of the coaxial cable 10 in FIG.
Has no effect on the differential current. Considering the human body detection of the automatic door, the sensing unit 5 is buried under the floor as shown in FIG. Then, a radio wave is radiated from the sensing unit 5, and the appearance is shown by the sensing plate 2 below.
Operates so as to be grounded to the ground, and radio waves are radiated from the upper sensing plate 1 onto the floor surface as X. In this way, if the Y part is perfect, an ideal switch that does not malfunction can be obtained, but since the X surface is also buried in the ground, the grounding condition of the Y surface is not perfect (due to construction work). Radio waves emitted from the Y surface are transmitted to the coaxial cable 10, and radio waves are radiated from the metal part (coaxial cable, sash, power line, etc.) 21 including the oscillating part 20, and the radio wave state Is not stable and malfunction occurs. Due to such a phenomenon, it was difficult to put this type of automatic door switch into practical use.

When the grounding state of the sensing plate 2 is bad, radio waves are radiated like a kind of dipole antenna, and when the length of the Y side antenna is changed by the metal 6 such as a power line, the radio wave emission state is changed,
The influence on the oscillator 20 causes the malfunction. In order to prevent this, the common-mode current blocking choke coil 4 is used.

In such an automatic door control device, if the radio wave emitted from the sensing plate 5 is blocked by the choke coil 4, the radio wave does not return to the sash 21 side, so that stable operation can be obtained. However, when the sensing plate 5 is installed close to the sash 21, that is, when the distance l in FIG. 9 is short or the radio wave conduction of the mortar is too good (when the mortar is not completely dry, the chemical reaction (ionization If there is a metal nearby and it easily flows to the sash side, a current may flow to the sash 21 side and flow into the oscillation unit 20, causing a malfunction.

(Object of the Invention) The present invention has been made under the circumstances described above.
SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic door control device in which the length of the feeder can be arbitrarily adjusted and the operation is stable in any case.

(Means for Solving the Problems) The present invention relates to an automatic door control device in which a control circuit including an oscillating unit is connected separately from a sensing unit. The object of the present invention is to connect to the sensing unit. An impedance converter, a feeder connected between the impedance converter and the oscillation unit, and a first common-mode current blocking choke coil interposed between the feeder and the impedance converter, This is achieved by providing a second common-mode current blocking choke coil interposed between the feeders or between the feeders and the oscillator.

According to the present invention, the first common-mode current blocking choke coil is provided between the impedance converter and the feeder of the sensing unit, and the second common-mode is provided between the feeders or between the feeder and the oscillating unit. By providing the die current blocking choke coil, a malfunction does not occur even when the sensing portion is arranged close to a metal portion such as a sash.

(Embodiment of the Invention) FIG. 1 shows an embodiment of the present invention in correspondence with FIG. 6, in which another common-mode current blocking choke 6 is inserted between coaxial cables 10. The conditions of the choke coils 4 and 6 are as follows: 1) The self-parallel resonance frequency f _{0 of the} choke coils 4 and 6 with respect to the working frequency f ₀ of the sensing unit used.
Is about 3 times or more 2) Choke coils 4 and 6
The inductance of is resonant with several tens of _P F (frequency f _b ),
Must be lower than the frequency f _0, 3) stroke used in the choke coil 4 and 6 are close to the characteristic impedance of the supply feeder 10, the 1) and 2) a magnetic material such as ferrite conditions fully to the It is necessary to wind as shown in FIG. 2 or FIG.

The change in the parallel resonance frequency f _OP is determined by the length 1 of the coaxial cable 10 and the capacitance C of the sensing plates 1 and 2. The length of the coaxial cable 10 needs the most freedom among the above three elements. That is, the length of the coaxial cable 10 required at the installation site of the automatic door is not known at the time of factory shipment, but it is shipped from the manufacturing factory at the maximum necessary length, adjusted at the installation site and cut to the required length. I am trying to do it. The maximum length of the coaxial cable 10 is limited to the relationship between the series resonance frequency f _os and the parallel resonance frequency f _OP .
As a method of increasing this length, there is a method of lowering the frequency of f ₀ or reducing the capacitance C of the sensing plate. In the former method, since it is necessary to insert the in-phase type current blocking choke coils 4 and 6, it is necessary to make the inductance larger than the above conditions 1) to 3) of the choke coil. The method of increasing the inductance of the choke coils 4 and 6 is to increase the magnetic induction rate μ ₀ of the wound core or to increase the number of turns of the choke coils 4 and 6, but the magnetic induction rate μ ₀
There is a limit to how many turns you can make. More turns means longer feeders, so
It is meaningless because it has the same correlation as lengthening the coaxial cable 10. Therefore, the capacitance C of the sensing plate is reduced to solve this problem. The impedance converter 3 is a method of reducing the capacitance C. Generally, the area of the sensing plate is 0.3m
^{Since 2 to 2} m ² is practically used, and it is considered that there is a capacitance difference of about 7 times, it is possible to cover with the same oscillation frequency f ₀ if the ratio of the impedance converter 3 is used properly.

That is, in order to prevent the radio wave radiated by the sensing unit 5 from flowing into the coaxial cable 10 again as an in-phase current and unnecessarily emitting the radio wave, as shown in FIG.
The coaxial cable 10 may be wound around the long rod 11 made of a magnetic material with high magnetic permeability such as a dust core to form a coil. Further, as shown in FIG. 3, the coaxial cable 10 may be wound around the toroidal core 13 made of the same material to form a coil. By winding the coaxial cable 10 as a coil in this manner, a current having the same magnitude as the jacket and the core wire and having opposite directions flows in the coaxial cable 10, so that a differential mode current is formed. Although not affected by the coil, the common-mode current is affected by the coil and does not flow to the oscillation side through the coaxial cable 10. Therefore, there is no unnecessary radiation due to the coaxial cable 10, and stable operation can be performed even when the grounding state of the sensing unit is poor.

The in-phase type current blocking choke coil 6 may be inserted between the coaxial unit 10 and the oscillator 20 as shown in FIG. In addition, although the coaxial cable has been described as an example in the above description, a feeder such as a bare twisted wire may be applied. Further, in the above embodiment, one in-phase current blocking choke coil is inserted for each, but a plurality of in-window current blocking choke coils may be connected in series and inserted.

[Brief description of drawings]

FIG. 1 is a connection diagram showing an embodiment of an automatic door control device according to the present invention, FIGS. 2 and 3 are diagrams showing examples of an in-phase current blocking choke coil used in the present invention, and FIG. FIG. 5 is a wiring diagram showing another embodiment of the present invention, FIG. 5 is a diagram showing a general automatic door control system, FIG. 6 is a wiring diagram showing an example of a conventional automatic door control device, and FIG. FIG. 8 is a diagram showing an equivalent circuit of the sensing system, FIG. 8 is a diagram showing an example of a reactance curve of the sensing system, and FIG. 9 is a diagram for explaining the operation of the automatic door sensing section. 1,2 …… Sensing plate, 3 …… Impedance converter, 4,6 ……
In-phase current blocking choke coil, 5 ... Sensor, 10 ...
… Coaxial cable, 20 …… Oscillator, 30 …… Automatic reset type DC amplifier.

Claims (1)

[Claims] 1. An automatic door control device in which a control circuit including an oscillating unit is connected separately from a sensing unit, and between an impedance converter connected to the sensing unit and the impedance converter and the oscillating unit. With a connected feeder,
A first common-mode current blocking choke coil interposed between the feeder and the impedance converter and a second common-mode current interposed between the feeder or between the feeder and the oscillating unit. An automatic door control device comprising a blocking choke coil.