JP2002298275A - Magnetic rotary link - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-channeling and a hollow axial structure by performing the transmission of a noncontact signal through a rotating shaft by a coil and a magnetoelectric conversion device to improve the problem of an optical system. SOLUTION: This magnetic rotary link comprises a concentric circular coil arranged in the center of the rotating shaft and the magnetoelectric conversion device arranged along the circumference of the coil with a rotatable gap, and has a basic structure for transmitting a signal even during rotation by detecting the magnetic field generated in the coil by the magnetoelectric conversion device through the gap when carrying an input signal current to the coil. A plurality of combinations of the basic structures are used to constitute the two-way communication and multi-channeling. The hollow axial structure can be mechanical provided by the method using the hollow cylindrical coil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for transmitting and receiving an electric signal via a rotating mechanism, and by transmitting a signal in a non-contact manner by combining a magnetic field generated by an electric current and a magneto-electric conversion element, thereby providing a reliable signal. While improving the
It is possible to increase the number of channels and the hollow shaft structure.

[0002]

2. Description of the Related Art In a rotary head part of a rotary electronic component automatic mounting apparatus, a joint part of a robot, a game machine, or the like, an actuator ( Mainly electric motors)
Alternatively, a structure equipped with the control device is often used. In this case, electric energy, that is, power is supplied from the fixed side, which is the apparatus main body, to the rotating mechanism side, and control signals are exchanged, that is, communication is performed between the fixed side control device and the rotation side control device. There is a need. In some cases, pneumatic or hydraulic actuators such as cylinders and chucks may be used on the rotating side.
It is also necessary to supply air pressure and hydraulic pressure via a rotation mechanism.
Conventionally, the most common method of supplying power and transmitting control electric signals is a contact method using a brush and a slip ring. The supply of air pressure or hydraulic pressure is generally performed by arranging a rotary joint for air pressure or hydraulic pressure at the center of the rotating shaft.

[0003] Conventionally, there has been a Japanese Patent Application No. 6-216123 "Electronic component automatic mounting apparatus" which makes communication of control electric signals non-contact. It is characterized in that it is provided at the center position. As another specific example of the optical communication member arranged at the center position of the rotation axis, there is Japanese Patent Application No. 11-212034 “Rotating light coupling device”, in which two sets of light emitting and receiving elements are arranged at the center part of the rotation axis. , Enabling two-way communication.

[0004] As another method of transmitting a signal without contact,
There is also a rotary transformer system used in the VTR head and resolver, but the characteristics of the transformer are determined by the size of the core air gap. It requires a high level of technology for the bearing structure, etc., and is expensive. In addition, it is impossible to transmit a DC component of a signal, and there is a problem that transmission of a high-speed signal requires a complicated circuit such as increasing a carrier frequency and performing modulation and demodulation.

[0005]

In the apparatus for transmitting energy and signals through the above-mentioned rotating mechanism, the supply of energy, that is, power, pneumatic pressure and hydraulic pressure is performed by a conventional method using a brush and a slip ring or a rotary joint. This is a general method, but for the control electric signal, since the signal handled becomes faster with the adoption of high-speed serial communication etc., the contact method using a brush and a slip ring for signal transmission is a signal transmission due to contact noise. Improvement of reliability has become a major issue, such as deterioration of characteristics and a problem of life due to wear. The method using optical communication to improve this also has the following problems. That is, since the light emission amount of a light emitting element such as a light emitting diode decreases with time, it is necessary to consider the life. Chile in the optical path
Since the signal transmission characteristics are degraded by dust and dirt, countermeasures are required. Since the permissible ambient temperature of the optical semiconductor is not so high, the operating temperature is limited. Although the configuration of one channel of the bidirectional communication is relatively easy, in order to increase the number of channels, means such as multiplex communication is required, and a high-speed response element, a modulation / demodulation means, a demultiplexing circuit, and the like are required. Complicated and expensive circuits are required. Instead, the method of using optical communication members for the number of channels becomes complicated and expensive in terms of mechanical structure. Further, the method of disposing the optical communication member at the center of the rotating shaft cannot employ a hollow shaft structure, and cannot incorporate a rotary joint for supplying pneumatic or hydraulic pressure to the center of the rotating shaft.

[0006]

According to the non-contact signal transmission device of the present invention, a coil which is a circular current path concentric with the center of the rotating shaft is arranged on the fixed side of the rotating mechanism, and the coil is arranged on the rotating side. Along the circumference of the coil, a rotatable air gap is provided and the magnetoelectric conversion element is arranged, and an input signal current flows through the coil,
A signal is transmitted from the fixed side to the rotating side by detecting the magnetic field generated by the current with the magneto-electric conversion element through the air gap.

On the rotating side of the rotating mechanism, a coil which is concentric with the center of the rotating shaft and forms a circular current path is arranged, and on the rotating side, a rotatable air gap is provided along the circumference of the coil. A magneto-electric conversion element is arranged, an input signal current flows through the coil, and a magnetic field generated by the current is detected by the magneto-electric conversion element through a gap, so that a signal is transmitted from the rotating side to the fixed side even during rotation.

In order to simultaneously transmit signals from the rotation side to the fixed side and from the fixed side to the rotation side, that is, to perform both signal transmissions, the above-described configurations are arranged concentrically in the radial direction.

In order to transmit signals of multiple channels, that is, a plurality of channels, a plurality of the above-described configurations are arranged in the radial direction.

In order to simultaneously transmit signals from the rotation side to the fixed side and from the fixed side to the rotation side, that is, to perform bidirectional signal transmission, the above-described configurations are arranged in combination in the axial direction.

In order to transmit signals of multiple channels, that is, a plurality of channels, a plurality of the above-described configurations are arranged in the axial direction.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the basic elements of a non-contact signal transmission device, that is, a magnetic rotary link according to the present invention. The structure is such that the rotating shaft 31 is rotated by the bearing 32 with respect to the fixed frame 33. A coil 1 serving as a fixed-side current path is formed on a surface of a printed circuit board 2 in a printed circuit pattern. The pattern shape of the coil 1 is the rotation axis 3
It is a circle of multiple turns concentric with the center of one. The rotation-side magnetoelectric conversion element 11 is mounted on a printed circuit board 12, and when the printed circuit board 12 is rotated via the rotation shaft 31, the magnetoelectric conversion element 11 maintains a small gap so as not to contact the coil 1. Rotate along the circumference of the coil while opposing 1. The processing circuit 3 for converting an input signal into a current signal is mounted on the back surface of the printed circuit board 2, and when a current flows through the coil 1, a magnetic field proportional to the current is generated around the coil. If an element for converting the intensity of the magnetic field into an electric signal, that is, the magnetoelectric conversion element 11 is arranged at a position interlinking with the magnetic field, an input signal on the fixed side can be transmitted to the rotating side without contact. Since the strength of the magnetic field is inversely proportional to the distance from the coil, it is desirable to arrange the magnetoelectric conversion element as close as possible to the coil. The processing circuit 13 that amplifies and converts the signal of the magnetoelectric conversion element and outputs the signal is mounted on the back surface of the substrate 12 here. Since the positional relationship between the circular coil 1 and the magnetoelectric conversion element 11 does not change even when the rotating shaft 32 rotates, it is possible to transmit a signal while rotating the shaft. The above-described method of forming a pattern of the coil 1 on a printed circuit board is a very advantageous method in terms of manufacturing because it does not require assembling the coil or connecting the coil terminals. Other methods, such as bonding a coil made by winding an electric wire onto a printed circuit board, can be used, but the time and labor for assembling and the number of steps for connecting terminals are increased. Since the rotating shaft 31 comes out into a hollow shaft structure, it is possible to incorporate a pneumatic or hydraulic supply rotary joint or other components (not shown here) into the hollow portion, and an air chuck or the like on the rotating side. For an application using an actuator such as a cylinder, a very advantageous structure is obtained.

FIG. 1 shows an example in which a signal is transmitted from the fixed side to the rotating side. Conversely, in order to transmit a signal from the rotating side to the fixed side, the relationship between the coil and the magnetoelectric conversion element is exchanged.
This can be realized by using a coil on the rotating side and a magneto-electric conversion element on the fixed side.

FIG. 2 shows that the above-mentioned components are arranged concentrically in the radial direction in order to transmit signals from the rotation side to the fixed side simultaneously from the fixed side to the rotation side, that is, to perform bidirectional signal transmission. An example will be described. In contrast to the embodiment of FIG. 1, a circular coil 14 and a signal processing circuit 15 concentric with a rotating shaft 31 are added to the rotating side substrate 12 on the inner diameter side with respect to the magnetoelectric conversion element 11, and the rotating side substrate 12 has a fixed side. The substrate 14 includes the coil 14
The magneto-electric conversion element 4 is disposed at a position opposing to the coil 1, that is, on the inner diameter side with respect to the coil 1, and a signal processing circuit 5 is further added to the back side of the substrate 2. With this configuration, it is possible to simultaneously perform signal transmission from the rotation side to the fixed side and from the fixed side to the rotation side, that is, perform bidirectional signal transmission.

FIG. 3 shows an embodiment for performing two sets of bidirectional communication of FIG. 2, that is, two channels of bidirectional communication. The method of concentrically arranging the circular coil and the magnetoelectric conversion element in the radial direction of the printed board is a structure convenient for using a printed board, but the outer diameter increases when the number of channels is increased.

FIG. 4 shows an embodiment in which the gap between the coil and the magneto-electric conversion element is set in the radial direction and the combination of a plurality of coils and the magneto-electric conversion element is arranged in the axial direction. Although there is some difficulty in mounting, there is a feature that the outer diameter can be reduced.

As the above-mentioned magnetoelectric conversion element, a magnetoresistance element, a giant magnetoresistance element, a Hall effect element, or the like can be used. The allowable ambient temperature of the optical semiconductor device is generally 75 to 85.
° C, whereas the magnetoelectric conversion element is 100-125.
The operation at a higher temperature is possible because of the high allowable ambient temperature of ° C. Since the detectable magnetic field of the magnetoresistive element and the giant magnetoresistive element is as small as several gauss to several tens of gauss, the signal can be transmitted with a small coil current. It is desirable that the operating magnetic field of the Hall effect element is slightly larger than that of the magnetoresistive element, but the price and availability of the element are excellent.

[0018]

According to the magnetic rotary link of the present invention, the problem of deterioration in signal transmission characteristics due to contact noise and life due to wear of the contact system using a brush and a slip ring can be avoided by making the contact non-contact. Reliability can be improved. In addition, there are problems in the non-contact method by optical communication, such as a problem of a life span in which a light emitting amount of a light emitting element such as a light emitting diode decreases with time, and a problem of deterioration of signal transmission characteristics due to dust, dirt, dirt, and the like in an optical path. Can also be avoided. Further, the magnetoelectric conversion element has a higher allowable ambient temperature than the allowable ambient temperature of the optical semiconductor, and thus can operate at a higher temperature. In terms of mechanical structure, the combination of a circular coil and a magnetoelectric transducer concentric with the center of the rotating shaft does not use the center of the shaft,
Since a hollow shaft structure can be adopted, a rotary joint for supplying pneumatic pressure or hydraulic pressure and other components can be incorporated in the center of the rotating shaft.

[Brief description of the drawings]

FIG. 1 is a sectional structural view showing a basic principle of an example signal transmission method according to the present invention.

FIG. 2 is a sectional structural view of a method of realizing signal transmission from the rotation side to the fixed side and simultaneously from the fixed side to the rotation side, that is, bidirectional signal transmission.

FIG. 3 is a cross-sectional structural view of an example in which two bidirectional channels are concentrically arranged in a radial direction as an example of a multi-channel.

FIG. 4 is a cross-sectional structural diagram of an example in which two channels are arranged side by side in the axial direction and the diameter is reduced as an example of multiple channels.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Fixed-side circular coil concentric with rotation axis 2 Fixed-side printed circuit board 3 Fixed-side input signal processing circuit 4 Fixed-side magnetoelectric conversion element 5 Fixed-side output signal processing circuit 11 Rotation-side circular coil concentric with rotation axis 12 Rotation-side printed circuit board 13 Rotation-side input signal processing circuit 14 Rotation-side magnetoelectric conversion element 15 Rotation-side output signal processing circuit 31 Rotation shaft 32 Bearing 33 Fixed-side frame

Claims (9)

[Claims] A coil having a circular current path concentric with the center of a rotating shaft is disposed on a fixed side of a rotating mechanism, and a rotatable air gap is provided on the rotating side along a circumferential portion of the coil. A magneto-electric conversion element is provided, an input signal current is supplied to the coil, and a magnetic field generated by the current is detected by the magneto-electric conversion element through an air gap, thereby transmitting a signal from the fixed side to the rotation side even during rotation. Magnetic rotary link. 2. A coil having a circular current path concentric with the center of the rotating shaft is arranged on the rotating side of the rotating mechanism, and a rotatable air gap is formed on the fixed side along the circumference of the coil. A magneto-electric conversion element is provided, an input signal current is supplied to the coil, and a magnetic field generated by the current is detected by the magneto-electric conversion element through an air gap, thereby transmitting a signal from the rotating side to the fixed side even during rotation. Magnetic rotary link. 3. The arrangement of the first and second aspects is combined and arranged concentrically in the radial direction, so that signal transmission from the rotation side to the fixed side and from the fixed side to the rotation side simultaneously, that is, both signal transmissions are performed. A magnetic rotary link that transmits signals. 4. A magnetic rotary link for transmitting signals of multiple channels by arranging concentrically in the radial direction by combining the configurations of claim 1 and 2. 5. The signal transmission from the rotation side to the fixed side and from the fixed side to the rotation side at the same time, that is, both signal transmissions, by combining and arranging the configurations of claim 1 and 2 in the axial direction. Do magnetic rotary link. 6. A magnetic rotary link for transmitting multi-channel signals by arranging the arrangement of claim 1 or 2 in a line in the axial direction. 7. A magnetic rotary link according to claim 1, wherein a circular coil concentric with the rotation axis is formed by a printed circuit pattern. 8. The magnetic rotary link according to claim 1, wherein a magnetoresistive element or a giant magnetoresistive element is used as the magnetoelectric conversion element. 9. The magnetic rotary link according to claim 1, wherein a Hall effect element is used as the magnetoelectric conversion element.