JP4494548B2 - Separable transformer and its signal transmission system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a separation-type transformer used for non-contact electric energy transmission and a signal transmission system thereof.
[0002]
[Related background]
The separate transformer is used for the signal transmission system between the steering wheel and the vehicle body, for example, the power required for the initiation of an automobile airbag, and the primary and secondary coils can be rotated relatively through a gap. It is configured.
In the signal transmission system, in order to supply the necessary power to the multiple signal transmission circuit, the power is supplied from the coil on one side to the multiple signal by the dielectric coupling of the primary side and secondary side coils of the separation transformer. It is transmitted to the coil on the other side to which the transmission circuit is connected.
[0003]
[Problems to be solved by the invention]
However, in such a system, since the gap between the coils is wide and fluctuates, the coupling efficiency between the coils is affected, and the transmission efficiency is deteriorated. Usually, a current of several hundred mA or more flows through the primary coil. There is a need. For this reason, in the said system, power consumption becomes large and a battery may go up while stopping.
[0004]
Therefore, there is a system in which the power supply of the entire system is turned on / off with the ignition key. However, if the ignition key is removed, the power supply is turned off and the entire system does not function. There are various loads for signal transmission, and a phon switch is one of them. The phone switch needs to be able to operate the phone even if the ignition key is removed. However, in the signal transmission system, if the ignition key is removed, the phone cannot be used like other loads.
[0005]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a separation-type transformer capable of transmitting a specific signal with a small current consumption and a signal transmission system thereof.
Another object of the present invention is to prevent interference between a specific signal and another signal.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, in the present invention, a primary side core, a secondary side core disposed opposite to the primary side core via a predetermined gap in the rotation axis direction, the primary side core, and the primary side core A separation type transformer having a primary coil and a secondary coil that are respectively wound around a secondary core and arranged so as to be inductively coupled to each other in the direction of the rotation axis, and are arranged via the predetermined gap on opposite sides of the primary core and the secondary core is, the opposed surfaces as an electrode bearing surface, the Rukoto electrostatic electrode thickness that does not affect the transformer efficiency are respectively provided, A separation type transformer is provided in which a parallel electrode type capacitor for signal transmission is formed between opposing surfaces of the primary side core and the secondary side core .
[0007]
That enable signal transmission with a small current consumption by the capacitor Nsu of the capacitor provided in the separation transformer gap space within the same space and. Preferably, each electrostatic electrode is provided with at least one insulating slit so that the electrostatic electrode does not become a one-turn coil.
[0008]
According to the present invention, there is provided a signal transmission system for transmitting a signal from at least one first signal transmission means via the separation-type transformer, wherein the signal is transmitted by a capacitor including the electrostatic electrode of the separation-type transformer. There is provided a signal transmission system using a separation type transformer, comprising a second signal transmission means for transmitting from one core side of the separation type transformer to the other core side.
[0009]
Preferably, in the signal transmission system, said second signal transmitting means, said first signal transmission means as a carrier frequency of the signal to be transmitted Ru with a frequency different from the carrier frequency of the signal to be transmitted. This prevents interference between the signals of the first signal transmission means and the second signal transmission means.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
A separation type transformer and its signal transmission system according to the present invention will be described with reference to FIGS.
FIG. 1 is a front view of a first example showing a rotary transformer as an embodiment of a separation type transformer according to the present invention in cross section. In the present embodiment, a case will be described in which the rotary transformer is used in a signal transmission system for transmitting power necessary for starting an air bag of a vehicle and a signal between a steering wheel and a vehicle body.
[0011]
In the figure, the rotary transformer 10 has a stator 12 attached to the column side (not shown) and a rotator 13 attached to the shaft 11 with the handle shaft 11 as a central axis. The primary side core 14 and the secondary side core 15 of the invention are opposed to each other so as to be relatively rotatable with a gap therebetween. The primary side coil 16 and the secondary side coil 17 of the present invention are mounted in annular recesses formed separately on the mutually opposing surfaces of the cores 14 and 15. Furthermore, the electrostatic electrodes 18 and 19 of the present invention are arranged to face the opposing surfaces of the cores 14 and 15 with the gap G interposed therebetween.
[0012]
In the present embodiment, the electrostatic electrodes 18 and 19 are configured by, for example, attaching an aluminum foil having a thickness of about 10 μm to the entire opposing surfaces of the cores 14 and 15 with, for example, an adhesive. Thus, in this embodiment, since the primary and secondary electrodes 18 and 19 face each other, one parallel electrode type capacitor 20 is obtained, and the capacitance C of the capacitor 20 is usually obtained by the following equation. .
[0013]
C = ε ₀ S / d
Where S is the surface area of the electrodes, d is the distance between the electrodes, and ε ₀ is the dielectric constant of air. That is, the capacitance C increases as the area of the electrodes increases and / or as the distance between the electrodes decreases. In the present embodiment, the electrodes 18 and 19 are attached to the entire opposing surfaces of the cores 14 and 15, but when the distance between the electrodes is very small, the diameter of the electrodes may be smaller than the core diameter. good.
[0014]
Further, the capacitance of the capacitor 20 varies depending on the change in the surface area of both electrodes. Therefore, in this embodiment, in order to minimize the change in capacitance when the rotary transformer 10 rotates, both electrodes 18 and 19 are formed in a circular shape as shown in FIG. Further, in order to suppress reduction in transformer transmission efficiency due to the electrodes, an insulating slit 21 is provided from the outer periphery of the electrodes 18 and 19 toward the center so as not to form a one-turn coil. It is effective to make the width of the slit 21 as small as possible in order to suppress the fluctuation of the capacitance due to the rotation of the rotary transformer 10. In the present embodiment, the case where one slit 21 is provided is shown, but the present invention is not limited to this, and it is possible to provide two or more slits.
[0015]
In addition, the wear resistance and mechanical strength increase as the thickness of both electrodes increases, but the transmission efficiency of the transformer deteriorates due to shielding, and there are restrictions in terms of cost and space when used for vehicles and the like. Therefore, as the provision of the scan Li Tsu bets, or instead thereof, for example, also to the thickness of the electrodes on only the thin does not affect the transformer transmission efficiency, suppress the reduction of the transformer transmission efficiency It is effective.
[0016]
FIG. 3 is a circuit diagram showing a configuration of a signal transmission system using the rotary transformer 10 shown in FIG. In the figure, a battery 31 as a power source is connected to the primary side coil 16 on the stator side of the rotary transformer 10 via an ignition key 30, and the secondary side coil 17 inductively coupled to the primary side coil 16 is connected to the secondary side coil 17. For example, a multiple signal transmission circuit and an initiation circuit (not shown) are connected, and signal transmission from the rotator side to the stator side and power supply from the stator side to the initiation circuit on the rotator side are possible.
[0017]
In addition, a phone control unit 32 is connected to the battery 31, and a phone 34 is connected via a switch 33. The phone control unit 32 is connected to the above-described capacitor 20 via a fixed resistor 35, and is connected between the fixed resistor 35 and the capacitor 20. The capacitor 20 is connected to the phone switch 36 on the rotator side. .
[0018]
As shown in FIG. 4, the phone control unit 32 includes a pulse signal generation circuit 32a connected to the battery 31 and the fixed resistor 35, a signal detection / processing circuit 32b connected between the fixed resistor 35 and the capacitor 20, and a signal. A phone ON / OFF control circuit 32c that performs on / off control of the switch 33 based on a signal from the detection / processing circuit 32b is configured. In the present embodiment, the switch 33 is composed of a MOS transistor, and performs a switching operation under the control of the phone ON / OFF control circuit 32c.
[0019]
That is, in the pulse signal generation circuit 32a of the phone control unit 32, even when the ignition key 30 is turned off, power is supplied from the battery 31, and a low-power pulse signal (AC signal) is generated. When the phone switch 36 is turned on, the pulse signal is added to the specific resistor 35, the electrostatic coupling capacitor 20, the phone switch 36, the handle shaft 11, and the common route. The voltage level of the voltage signal Vs greatly fluctuates.
[0020]
That is, when the phon switch 36 is off, the voltage level of the voltage signal Vs is approximately equal to the voltage level of the voltage signal Vh. When the phon switch 36 is on, the voltage level of the voltage signal Vh is The voltage is divided between the capacitance and the resistance value of the specific resistor 35, and (voltage level of the voltage signal Vs) >> (voltage level of the voltage signal Vh), for example, (voltage level of the voltage signal Vh) = (voltage level of the voltage signal Vs) ) / 2, which is sufficiently small. In the signal detection / processing circuit 32b, after the voltage signal Vh is detected and converted into a DC voltage level, the magnitude thereof is compared with a predetermined reference value, and a signal corresponding to the determination result is sent to the phone ON / OFF control circuit. It outputs to 32c. The phone ON / OFF control circuit 32 c controls the MOS transistor 33 on / off based on the above signal to enable power supply from the battery 31 to the phone 34.
[0021]
Thus, in this embodiment, the primary side and the secondary side of the surface of the core which is oppositely arranged with a gap, by providing an electrostatic electrode respectively constitute one capacitor, smaller by a capacitor Nsu capacitor Since the signal can be transmitted from the secondary side to the primary side with the current consumption, a specific signal such as a phone switch signal for operating the phone can be transmitted with a small current consumption. Power can be supplied.
[0022]
FIG. 5 is a front view of a second example showing a rotary transformer as a cross-section as an embodiment of the separation type transformer according to the present invention, and FIG. 6 is a signal transmission using the rotary transformer shown in FIG. It is a circuit diagram which shows the structure of a system. In the following embodiments, the same components as those in FIGS. 1 to 4 are denoted by the same reference numerals for convenience of explanation.
[0023]
5 is different from FIG. 1 in that the primary side coils 16a and 16b and the secondary side coil are formed in a plurality of annular recesses formed separately on the mutually opposing surfaces of the cores 14 and 15, respectively. 17a and 17b are respectively mounted.
As shown in FIG. 6, a battery 31 is connected to one end of the primary coils 16 a and 16 b via a stator ECU 40 and an ignition key 30.
[0024]
A pulse signal generation circuit 42 is connected to the other end of the primary side coil 16a via a MOS transistor 41. The pulse signal generation circuit 42 is also connected to the ECU 40, operates under the control of the ECU 40, and operates at a carrier frequency. The pulse signal of f1 is output to the primary side coil 16a via the MOS transistor 41.
The secondary coil 17a that is inductively coupled to the primary coil 16a is connected to an initiation circuit 50 made of a resistance for initiating a vehicle airbag, and from the battery 31 on the column side to the initiation on the handle shaft side. Electric power can be supplied to the circuit 50.
[0025]
A pulse signal generation circuit 44 is connected to the other end of the primary side coil 16b via a MOS transistor 43. The pulse signal generation circuit 44 is also connected to the ECU 40, operates under the control of the ECU 40, and operates at a carrier frequency. The pulse signal f2 is output to the primary coil 16b via the MOS transistor 43. A multiplex signal transmission circuit 53 is connected to the secondary side coil 17b inductively coupled to the primary side coil 16b via a resonance circuit 52 including a rectifier circuit 51, a coil L, and capacitors C1 and C2, and a handle shaft. The resonance frequency f1 generated by the operation of the multiple signal transmission circuit 53 on the side is detected by operating the pulse signal generation circuit 44 provided on the primary side to generate a pulse signal of the frequency f1. .
[0026]
Further, the phon control unit 32 that controls the activation of the phon 33 has the same configuration as that of FIG. 4, and the pulse signal generation circuit 32 a is configured to avoid interference with the multiplex transmission signal during transmission of the phon switch signal. The carrier frequency is set to a frequency f3 different from the frequencies f1 and f2, and a pulse signal is output.
As described above, in this embodiment, the power transmission system for air bag initiation and the signal transmission system for multiplexed signal transmission are separately provided on the primary core and the secondary core of the rotary transformer, respectively. In addition, a signal transmission system for phon switch signals using electrostatic electrodes is provided separately from these transmission systems, and signal transmission is performed by setting the carrier frequencies of these transmission systems to different frequencies. Can be transmitted with a small current consumption, and interference with the multiplexed transmission signal can be prevented during transmission of the phone switch signal.
[0027]
In these embodiments, since the electrostatic electrodes made of aluminum foil are provided on the opposing surfaces of the primary side and secondary side cores, even if the two cores come into contact with each other due to a gap variation, the electrostatic electrodes However, it becomes possible to prevent the coil from being damaged by acting as a protective cover. The present invention is not limited to these examples, and various modifications can be made without departing from the scope of the present invention.
[0028]
If the signal transmission system shown in FIG. 3 is constructed using the rotary transformer configured as described above, a specific signal such as a phone switch signal for operating the phone can be transmitted with a small current consumption, as in the first embodiment. This makes it possible to supply power from the battery to the phone.
Therefore, in these embodiments, by transmitting the phone switch signal from the secondary phone switch by the electrostatic electrode, the power consumption becomes very small, and even if the power is turned off with the ignition key, the phone control unit A current can be passed, and the phone can be turned on / off.
[0029]
【The invention's effect】
As described above, in the first aspect of the present invention, the primary side core, the secondary side core disposed opposite to the primary side core in the rotation axis direction through a predetermined gap, and the primary side A separation type transformer having a primary side coil and a secondary side coil wound around a core and a secondary side core and arranged so as to be inductively coupled to each other in the rotation axis direction, with a predetermined gap interposed therebetween An electrostatic electrode having a thickness that does not affect the transformer efficiency is provided on the opposed surfaces of the primary side and the secondary side, with the opposing surfaces serving as electrode support surfaces, respectively, and the primary side core and Since the parallel electrode type capacitor for signal transmission is formed between the opposing surfaces of the secondary core, it is possible to transmit a specific signal with a small current consumption through the electrostatic electrode.
[0030]
According to a third aspect of the present invention, the primary side core, the secondary side core disposed opposite to the primary side core via a predetermined gap in the rotation axis direction, and the primary side core and the secondary side core are wound respectively. And a separation type transformer having a primary side coil and a secondary side coil arranged so as to be inductively coupled with each other in the direction of the rotation axis , and from at least one first signal transmission means via the separation type transformer A signal transmission system for transmitting signals, wherein the separation transformer includes the separation transformer according to claim 1 or 2, and a signal is transmitted to one of the separation transformers by a capacitor including the electrostatic electrode. Since the second signal transmission means for transmitting from the core side to the other core side is provided, the electrostatic signal capacitor enables signal transmission from the second signal transmission means with a small current consumption.
[0031]
In the present invention, since the second signal transmission means sets the carrier frequency of the signal to be transmitted to a frequency different from the carrier frequency of the signal transmitted by the first signal transmission means, the second signal transmission means transmits the signal. It is possible to prevent interference between the specific signal to be transmitted and the other signal transmitted by the first signal transmission means.
[Brief description of the drawings]
FIG. 1 is a front view of a first example showing a rotary transformer as an embodiment of a separation type transformer according to the present invention in cross section.
FIG. 2 is a plan view of the electrostatic electrode shown in FIG.
3 is a circuit diagram showing a configuration of a signal transmission system using the rotary transformer shown in FIG. 1. FIG.
4 is a circuit diagram showing a configuration of a phone control unit shown in FIG. 3. FIG.
FIG. 5 is a front view of a second embodiment showing a rotary transformer according to the present invention in cross section.
6 is a circuit diagram showing a configuration of a signal transmission system using the rotary transformer shown in FIG. 5. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Rotation transformer 11 Handle shaft 12 Stator 13 Rotator 14, 15 Core 16, 17, 16a, 16b, 17a, 17b Coil 18, 19, 24, 25 Electrostatic electrode 20 Capacitor 21 Slit 30 Ignition key 31 Battery 32 Phone control unit 32a , 42, 44 Pulse signal generation circuit 32b Signal detection / processing circuit 32c Phone ON / OFF control circuit 33, 41, 43 MOS transistor 34 Phone 35 Fixed resistor 36 Phone switch 40 Stator side ECU
50 Initiation Circuit 51 Rectification Circuit 52 Resonance Circuit 53 Multiplex Signal Transmission Circuit G Gap

Claims (4)

A primary side core, a secondary side core disposed opposite to the primary side core via a predetermined gap in the rotation axis direction, and wound around the primary side core and the secondary side core, respectively. A separation type transformer having a primary side coil and a secondary side coil arranged so as to be inductively coupled in a rotation axis direction,
An electrostatic electrode having a thickness that does not affect the transformer efficiency is formed on the opposing surfaces of the primary core and the secondary core disposed via a predetermined gap, with the opposing surfaces as electrode support surfaces. by respectively provided Rukoto, separating type transformer, wherein a parallel-electrode-type capacitors for signal transmission is formed between opposing surfaces of the primary core and the secondary core.   2. The separated transformer according to claim 1, wherein each electrostatic electrode is provided with at least one insulating slit. A primary side core, a secondary side core disposed opposite to the primary side core via a predetermined gap in the rotation axis direction, and wound around the primary side core and the secondary side core, respectively. A separation type transformer having a primary side coil and a secondary side coil arranged so as to be inductively coupled in the direction of the rotation axis is provided, and a signal is transmitted from at least one first signal transmission means via the separation type transformer. A signal transmission system,
The separation-type transformer includes the separation-type transformer according to claim 1 or 2, and a signal is transmitted from one core side of the separation-type transformer to the other core side by a capacitor including the electrostatic electrode. A signal transmission system using a separation-type transformer, characterized by comprising second signal transmission means.   4. The separation type transformer according to claim 3, wherein the second signal transmission means sets the carrier frequency of the signal to be transmitted to a frequency different from the carrier frequency of the signal transmitted by the first signal transmission means. The signal transmission system used.

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