JP3599568B2 - Rotation angle detection method and rotation angle detection device using rotary transformer - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a rotation angle detection method and a rotation angle detection device using a rotary transformer.
[0002]
[Prior art]
The separation-type transformer has a core having a coil arranged with the coils opposed to each other, and transmits electric power and an electric signal between the two coils in a non-contact manner by electromagnetic coupling between the opposed coils. Such a separation type transformer is also used as a rotary type transformer in which each core relatively rotates. For example, an airbag mounted on a steering device of an automobile and provided on a steering side rotating from a steering column side fixed to a vehicle body. Can be used as transmission means for transmitting operating power or the like to the detonating device.
[0003]
On the other hand, in recent years, for example, an optical rotary encoder is incorporated in a steering device as a detection mechanism for detecting a steering angle in order to perform roll control during steering in a vehicle.
[0004]
[Problems to be solved by the invention]
By the way, in a steering apparatus of an automobile, various devices and components such as a rotary transformer and a horn switch for starting the airbag are densely arranged. Therefore, in designing a steering apparatus for an automobile, it is difficult to secure a space for mounting the steering angle detecting mechanism.
[0005]
For this reason, for example, a space for mounting the encoder is secured by taking measures such as reducing the thickness of the rotary transformer in the rotation axis direction or reducing the diameter.
[0006]
However, when devices and components such as the steering angle detection mechanism and the rotary transformer are individually manufactured and mounted on a steering device, there is a problem that manufacturing costs, mounting costs, and inspection costs are increased.
[0007]
The present invention has been made in view of the above, to reduce the space occupied by the rotation angle detecting Organization and rotary transformers, manufacturing cost and mounting cost, and further it is possible to reduce the inspection cost of equipment and the like An object of the present invention is to provide a rotation angle detection method and a rotation angle detection device using a rotary transformer.
[0008]
[Means for Solving the Problems]
Since in the present invention to achieve the above object, respectively provided with a rotary member and a stationary member having the a core of the coil and the magnetic material, is disposed opposite the rotator side core of the stator side core and the rotating member of the fixing member wherein a rotation angle detection method using a rotary transformer which electrical transmission in a non-contact power or electric signals between the stator-side core and the rotator-side core Te, detection for the rotation angle detecting the outer periphery of said rotary member a plurality of parts provided Rutotomoni, provided electromagnetic or optically detectable detection means the detection portion at a position different from that of the stator-side core in said stationary member, by the detection means, the rotation angle of said rotary member Provided is a rotation angle detection method for detecting .
[0009]
Preferably, the detection unit is any one of irregularities, holes, and slits.
Further, the present invention provides a rotation angle detection device in which the above-described rotary transformer includes the detection unit and the detection unit.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, various embodiments of the present invention will be described in detail with reference to FIGS.
[0011]
First, a rotary transformer to which a rotation angle detection method and a rotation angle detection device of the present invention are applied will be described below.
[0012]
The rotary transformer 1 is used, for example, by attaching it to a steering device. As shown in FIG. 1, the primary core 2 and the secondary core 3 have a predetermined gap G (= about 2 to 0.2 mm). Two detectors 5 are arranged on the outer periphery of the secondary core 3 so as to be displaced in the circumferential direction and opposed to the secondary core 3. At this time, the primary core 2 is attached to the vehicle body, and the secondary core 3 is attached to the steering handle.
[0013]
The primary side core 2 and the secondary side core 3 are each made of a synthetic resin containing a soft magnetic material, and are provided with two grooves in the circumferential direction on opposite surfaces of the disk-shaped cores 2a, 3a having an opening at the center. 2b, 2c and grooves 3b, 3c are formed, and coils 2d, 2e and coils 3d, 3e each having a rectangular wire wound around each groove are arranged. As shown in FIG. 2, the secondary core 3 is provided with a plurality of detectors 3 f formed on the outer periphery thereof with unevenness at equal intervals.
[0014]
Since the secondary core 3 rotates in synchronization with the rotation of the steering handle, the detection unit 3f depends on the resolution of the rotation angle at which the circumferential interval of the unevenness is detected. For example, when information of every four degrees is required as the rotation angle, the unevenness is formed by dividing the circumference equally by 90.
[0015]
Here, the soft magnetic material refers to a material having a property of extremely low residual magnetism.
[0016]
The cores 2a and 3a are formed in a ring shape by mixing a predetermined amount of soft magnetic ferrite powder such as Ni-Zn ferrite or Mn-Zn ferrite into a synthetic resin such as nylon or polyphenylene sulfide (PPS). It is molded. Core 2a, 3 a may use a ring-shape molded a soft magnetic ferrite sintered body (e.g., those sintered by mixing a binder agent in Ni-Zn ferrite or Mn-Zn ferrite, etc.) .
[0017]
The coils 2d and 2e and the coils 3d and 3e are formed into a ring shape, for example, by winding an electric wire such as a winding obtained by overcoating a polyurethane insulating coating with a polyamide fusion coating over a predetermined number of times according to the intended use. One of the winding end surfaces is flush with the opposing surfaces of the cores 2a and 3a. As long as the coils 2d and 2e and the coils 3d and 3e can be formed into a ring shape, the cross section of the conductor of the electric wire may be circular, rectangular or any shape. At this time, for example, large coils 2d and 3d are used for instantaneously transmitting relatively large electric power for starting the airbag, and coils 2e and 3d are used for transmitting a small current such as an electric signal of an auto cruise system. Use 3e.
[0018]
The detecting means 5 covers the periphery of a yoke 5b attached to the permanent magnet 5a with a coil 5c, and responds to a change in magnetic flux density generated in the permanent magnet 5a by the detecting unit 3f with the rotation of the secondary core 3. The applied voltage is excited in the coil 5c. That is, the detecting means 5 utilizes the fact that the rotation of the secondary core 3 causes a change in magnetic flux due to a change in the gap between the detecting portion 3f of the core 3a, which is a magnetic material, and the permanent magnet 5a.
[0019]
At this time, in order to detect the steering angle, it is necessary to identify the rotation direction (left-right direction) of the steering wheel. For this reason, two detectors 5 are arranged so that the phase difference of the voltage excited by the coil 5c becomes 90 degrees.
[0020]
Therefore, the electromotive force e excited in the coil 5c is the product of the number of turns N and the time derivative (d 磁 束 / dt) of the magnetic flux density 、, where N is the number of turns of the coil 5c and 磁 束 is the magnetic flux density. ).
Δe = −N · dφ / dt (1)
[0021]
As described above, when the secondary core 3 rotates with the rotation of the steering handle, two types of voltages A and B having a phase difference of 90 degrees are excited in the two detecting means 5 as shown in FIG. . These voltages A and B are taken out, the waveform is shaped by an electric signal processing means such as a comparator and the like, and a pulse having two kinds of phase differences is obtained. The angle can be detected with high accuracy.
[0022]
With such a detection method, the space occupied by the two detection means 5 and the rotary transformer 1 can be reduced, and the manufacturing cost, the mounting cost, and the inspection cost of equipment and the like can be reduced.
[0023]
Here, the secondary core 3 has a configuration in which the detection unit 3f formed into unevenness at equal intervals is provided on the outer periphery. However, if there is a degree of freedom in arrangement, as shown in FIG. Alternatively, a number of projections 7a may be provided on the upper surface at equal intervals. At this time, the detecting means 5 is arranged above the secondary core 7 so as to face the many protrusions 7a.
[0024]
On the other hand, the method and the apparatus of the present invention may detect the rotation angle of the rotary transformer 1 using the detection means 8 shown in FIG.
[0025]
That is, the detecting means 8 has a core 8a made of sintered sendust or permalloy having a high relative permeability and a pickup coil 8b. At this time, a current I flows through the pickup coil 8b, and the magnetic resistance corresponding to the concave portion of the detecting portion 3f with the rotation of the secondary core 3 is R0, and the magnetic resistance corresponding to the convex portion of the detecting portion 3f is R0. Assuming that R, an electromotive force represented by the following equation based on the equation (1) is generated according to a change in magnetoresistance due to the presence or absence of a protrusion of the detection unit 3f.
Δe = −N · Δφ / Δt = −N · (NI / R−NI / R0) / Δt (2)
[0026]
Therefore, by performing the same processing as in the above-described embodiment, a predetermined angle signal, that is, the rotation angle of the secondary core 3 (steering handle) can be detected.
[0027]
Next, the method and apparatus of the present invention can be applied to the rotary transformer 10 shown in FIG.
[0028]
Generally, when a rotary transformer is mounted on a steering device, it is necessary to apply a magnetic shield to the rotary transformer in order to suppress malfunctions and emission of electromagnetic induction noise depending on the transmission frequency and transmission power used. is there.
[0029]
The rotary transformer 10 takes such magnetic shielding measures into consideration, and includes a primary core 11, a secondary core 12, and a primary core 11 that are arranged to face each other with a predetermined gap G (= about 2 to 0.2 mm). A primary core 11 is attached to the vehicle body side, and a secondary core 12 is attached to the steering handle side.
[0030]
The primary side core 11 and the secondary side core 12 are each made of a synthetic resin containing a soft magnetic material, and are provided with two grooves in the circumferential direction on the opposing surfaces of the disk-shaped cores 11a, 12a having an opening at the center. 11b, 11c and grooves 12b, 12c are formed, and coils 11d, 11e and coils 12d, 12e each having a rectangular wire wound in each groove are arranged.
[0031]
The shielding plate 13 is disposed on the secondary core 12 and is a disk-shaped metal plate made of aluminum, copper, or the like, has an opening 13a at the center, and has a plurality of outer peripheral portions corresponding to the rotation angle detection accuracy. Are provided at equal intervals in the circumferential direction.
[0032]
Then, the shield plate 13 detects the slit 13 b by the LED light source 16 and the photosensor 17 attached to the attachment jig 15 provided on the vehicle body side, and thereby the secondary core 12 is formed in the same manner as the magnetic sensor. In addition to being able to detect the rotation angle with high accuracy, it is also possible to reduce the influence of disturbance by shielding electromagnetic induction noise to the rotary transformer 10 and to save the space required for the rotation angle detection. .
[0033]
Further, the method and apparatus of the present invention can be applied to the rotary transformer 20 shown in FIG.
[0034]
In the rotary transformer 20, a primary core 21 and a secondary core 22 are arranged to face each other via a predetermined gap G (= about 2 to 0.2 mm). The secondary core 22 is attached to the steering handle.
[0035]
The primary side core 21 and the secondary side core 22 are each made of a synthetic resin containing a soft magnetic material, and are formed with two grooves in the circumferential direction on the opposing surfaces of the disk-shaped cores 21a, 22a having an opening at the center. 21b, 21c and grooves 22b, 22c are formed, and coils 21d, 21e and coils 22d, 22e each having a rectangular wire wound around each groove are arranged. The primary side core 21 is provided with a large number of detection holes 21f on the outer periphery of the core 21a. The secondary core 22 has an edge 22f protruding from one side, and a support 25 is provided on the edge 22f. An LED light source 26 and a photo sensor 27 are attached to the support 25, and by detecting the detection holes 21f with these, the rotation angle can be detected with high accuracy in the same manner as the magnetic sensor.
[0036]
The above embodiment has been described for the case of detecting the steering angle of the vehicle steering apparatus as the rotation angle detecting method and the rotation angle detecting apparatus using a rotary transformer.
[0037]
However, the rotation angle detecting method and the rotation angle detecting apparatus using a rotary transformer of the present invention, if detecting the rotation angle between two members that rotate relative to one another for transferring power or electric signals in a non-contact, detected is not to mention not limited to the steering angle, for example, a method for detecting a rotation angle between the member cross with the rotation angle of the hinge portion and a robot arm of a motor vehicle door, the freedom of rotation and It can also be used as a device . In addition, although the primary side core and the secondary side core each have two coils provided in each core, it is needless to say that the number of coils is not limited to this.
[0038]
【The invention's effect】
According to the invention of claims 1 to 3, to reduce the space occupied by the rotation angle detecting Organization and rotary transformers, manufacturing cost and mounting cost, rotary transformer further capable of reducing the inspection cost of equipment and the like And a rotation angle detection device using the same.
[Brief description of the drawings]
FIG. 1 is a sectional front view of a rotary transformer and a detecting means for explaining a method of the present invention.
FIG. 2 is a perspective view showing a detection unit including irregularities on a secondary core used in the rotary transformer of FIG. 1;
FIG. 3 is a waveform diagram of two kinds of voltages having different phases by 90 degrees which are excited by two detecting means provided in the rotary transformer of FIG. 1;
FIG. 4 is a perspective view showing a modified example of a secondary core in a rotary transformer to which the method of the present invention is applied.
FIG. 5 is a sectional front view of a rotary transformer and a detecting means showing another example of the method of the present invention.
FIG. 6 is a cross-sectional front view of a rotary transformer and a detecting means showing still another example of the method of the present invention.
FIG. 7 is a cross-sectional front view of a rotary transformer and a detecting means showing another example of the method of the present invention.
[Explanation of symbols]
Single- turn type transformer 2 Primary side core 2a Core 2d, 2e coil 3 Secondary side core 3a Core 3d, 3e coil 3f Detector (irregularities)
5 Detecting means 5a Permanent magnet 5b Yoke 5c Coil 7 Secondary core 7a Projection 8 Detecting means 8a Core 8b Pickup coil 10 Rotary transformer 11 Primary core 11a Core 11d, 11e Coil 12 Secondary core 12a Core 12d, 12e Coil 13 Shielding plate 13a Opening 13b Slit 16 LED light source 17 Photosensor 20 Rotary transformer 21 Primary core 21a Core 21d, 21e Coil 21f Detection hole 22 Secondary core 22a Core 22d, 22e Coil 26 LED light source 27 Photo sensor G gap

Claims (3)

A rotary member which chromatic and rotator side core of the coil and the magnetic material, coil and a fixing member having a stator side core of magnetic material, the said rotator side core and the stator-side core are opposed disposed stator a rotational angle detection method using the rotary transformer for electrical transmission in a non-contact power or electrical signals to and from the rotator side core and the side core,
The rotating member of the outer peripheral portion in the rotation angle detecting the detector plurality of Rutotomoni, provided electromagnetic or optically detectable detection means the detection portion at a position different from that of the stator-side core in said stationary member A rotation angle detecting method using a rotary transformer, wherein the detecting means detects a rotation angle of the rotating member. 2. The rotation angle detecting method according to claim 1, wherein the detection unit is any one of an unevenness, a hole, and a slit. A rotating member having a coil and a rotator-side core made of a magnetic material; and a fixed member having a coil and a stator-side core made of a magnetic material. A rotary transformer for transmitting electric power or an electric signal in a non-contact manner between the core and the rotator-side core,
A plurality of detecting units for detecting a rotation angle provided on the outer peripheral portion of the rotating member,
A detection unit that is provided at a position different from the stator-side core in the fixing member, detects the detection unit electromagnetically or optically, and detects a rotation angle of the rotation member;
A rotation angle detection device using a rotary transformer, comprising:

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