JPS62160005A - Position detector for magnetic levitation traveling apparatus - Google Patents

Abstract

PURPOSE:To alleviate a shock to be applied to a traveling slider by a gap even if a gap is formed at a seam of guide rails by averaging the inductance of a spiral coil of each sensor head, and outputting a displacement signal according to the averaged value. CONSTITUTION:A sensor head 70 for detecting a gap between a slider and the guide surface 20a of a guide rail 20 has spiral coils 701-703 arranged at a predetermined interval in the moving direction of the slider. The head 70 averages the inductances of the coils 701-703, and a tuner 80 and a detector 83 output the averaged value of gaps between the coils 701-703 and the rail 20. The intervals of the coils 701-703 are set to the gap which does not simultaneously generate a variation in the inductance due to the gap of the seal 20 of the rail 20 in two or more coils.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a position detector for a magnetically levitated traveling device in which a slider is levitated by magnetic force and travels along a guide rail.

In the magnetic levitation traveling device, the slider includes a magnetic bearing for levitation and a magnetic bearing for left-right direction control, which are provided on the slider.
It is necessary to detect the gap between the guide rail and the guide surface and control the slider to an appropriate position.

By the way, if the guide rail has a joint and there is a gap between the joints, even if the gap is small,
This causes a sudden change in the detected value, and the shock causes inconveniences such as the traveling slider hitting the guide rail, so it is required to form a joint with no gaps. Therefore, in order to prevent this gap from being detected, conductive target tape is pasted along the entire length of the guide rail.

However, there is a limit to the length of the target tape, so
If the guide rail is longer, you will have to deal with gaps in the joints in the target tape itself, and if the guide rail has a switching branch, there will always be gaps in the guide rail joints at that part. However, there is a problem in that rapid changes in detected values cannot be avoided.

The present invention has been made in view of the above circumstances, and provides a position detector for a magnetically levitated traveling device that alleviates shocks caused to a traveling slider due to gaps in the joints of guide rails. is intended to provide.

In order to achieve the above-mentioned object of increasing the divination, the present invention provides a magnetic levitation type traveling device in which a slider is levitated by magnetic force and travels along a guide rail. A plurality of sets of sensor heads arranged facing each other on a surface, a capacitor forming a tuned circuit in pairs with the sensor head, a high-frequency oscillation circuit that drives the tuned circuit, and a detection unit that detects the high frequency generated in the tuned circuit. and a low-pass filter that blocks high-frequency components after detection.

The sensor head has a plurality of flat spiral coils arranged side by side in the direction of movement of the slider at intervals such that changes in inductance due to gaps between guide rail joints do not occur in two or more spiral coils at the same time.

The high frequency from the dish high frequency oscillation circuit is applied to the tuning circuit and the detection section. At this time, the inductances of the respective spiral coils of each set are averaged, and when the averaged value changes, the tuning frequency of the tuned circuit changes. As a result, the strength of the high frequency input to the detection section changes in accordance with the tuning frequency, and the detection section outputs a signal corresponding to the averaged value of each gap between each spiral coil and the guide rail. is output. Then, the low-pass filter extracts only the displacement output included in the detected signal.

Figure 2 is a longitudinal sectional view of a magnetic levitation type traveling device according to an embodiment of the present invention.

In this figure, the leg portions 30 of the guide rail 20 are fixed on the base 10, guide portions 21 and 21 protrude from both sides of the guide rail 20, and the stator 23 of the induction type linear motor is located at the upper center of the guide rail 20. is located.

On the other hand, the slider 40 includes vertical plates 41.42 arranged on both sides of the guide rail 20, and upper horizontal plates 43.44 extending from above and below the dark blue plate 41.42 to the lower part of the guide part 21.21.
and lower horizontal plates 45 and 46. The secondary conductor 47, which faces the stator 23 and constitutes the linear motor with the stator 23,
4 are connected to each other. The upper surface of the secondary conductor 47 is covered with a pallet 49 while maintaining a gap 48, and a plurality of electric circuit boards 5o are arranged in the gap 48.

Two locations on the front and back of the upper surface of the lower horizontal plate 45 and 46 of the slider 40 (
(see Fig. 3) are provided with magnetic bearings 60A, 60B, 60G, 600 for vertical direction guidance made of electromagnets,
The magnetic pole surfaces 60J of the left magnetic bearings 60A and 60B face the lower guide surface 21J of the left guide portion 21 with a required gap, and the magnetic pole surfaces 60 of the right magnetic bearings 60C and 600 have the right lower guide surface 21K. are opposed to each other with a predetermined gap. In addition, magnetic bearings 60E for left and right guidance made of electromagnets are installed at two locations on the front and back of the inner surfaces of the vertical plates 41 and 42.
, 60F, 60G, and 60H, the magnetic pole faces 60L of the left magnetic bearings 60E and 60F face the side guide surface 21L of the left guide part 21 with a required gap, and the magnetic pole faces 60L of the right magnetic bearings 60G and 60H Magnetic pole face 60M
is opposed to the side guide surface 21M of the right guide portion 21 with a required gap.

A first sensor head 70a (see FIG. 3) and a second sensor head 70 for detecting the gaps between the magnetic bearings 60A, 60B and 60C160D and the guide surfaces 21J and 21 and controlling the vertical posture of the slider 40.
b is located near the magnetic bearings 60A and 60B, and the third sensor head 70c is located between the magnetic bearings 60C and 600, respectively. In addition, magnetic bearings 60E, 60F
and 60G, 60H and guide surfaces 21L and 21M
A first sensor head 70d and a second sensor head 70d for detecting the gap between the
Sensor 70e is located near magnetic bearings 60E, 60F. In FIG. 3, 80 is a battery.

FIG. 4 is a front view of the sensor head 70 (ae) described above. Each set of sensor heads 70 (a-e) faces a predetermined guide surface 21 (J-M) of the guide rail 20, and is arranged in parallel in the direction of movement of the slider 40, that is, in the direction of arrow A. Spiral coil 701.702.7
It consists of 03. Each set of spiral coils 701.702
．． 703 are attached to the surface of the resin plate 200 by an etching method, and are connected in series (see FIG. 1) with a gap maintained so that they do not affect each other electrically. Further, a coaxial cable 400 (see FIG. 5) is connected to both ends of each set of spiral coils 701, 702, 703 from below the resin plate 200 through through holes 301, 302.

As shown in FIG. 5, the resin plate 200 is fixed to a holder 500 for attachment to the slider 40, and a cable insertion hole 501 of the attachment holder 500 is filled with molded resin 601. In addition, each spiral coil 701.702.703
is covered with a protective seal 602 made of resin, glass, or the like.

In addition, specifically, the mounting holder 400 is attached to the slider 40.
The inner surfaces of the vertical plates 41 and 42 and the upper surfaces of the lower horizontal plates 45 and 46,
Alternatively, as shown in FIG. 6, it is attached to the side of the core of a magnetic bearing 60 (E-H).

FIG. 1 is a block diagram of the position detection circuit. This position detection circuit includes a capacitor 81 that forms a tuned circuit 80 in pairs with the spiral coils 701, 702, and 703, a high frequency oscillation circuit 82 that drives this tuned circuit 80, and a tuned circuit 8.
It consists of a detection section 83 that detects high frequency components occurring at 0, and a low pass filter 84 that blocks high frequency components after detection.

FIG. 7 is a block diagram of the position control device. In this figure, 90a, 90b, and 90c are the position detectors explained in FIG. 1, the position detector 90a is the sensor head 70a in FIG. 3, and the position detector 90b is the sensor head 70b
The position detectors 90c each include a sensor head 70C. Further, 101 is an arithmetic circuit, and 102 is a control circuit.

Next, the operation of the above configuration will be explained.

In FIG. 1, a high frequency wave from a high frequency oscillation circuit 82 is applied to a tuning circuit 80 and a detection section 83.

At this time, in each set of sensor heads 70 (a-e), each spiral coil 701.702.703 of each set
The inductances are averaged, and when the averaged value changes, the tuning frequency of the tuning circuit 80 changes. As a result, the strength of the high frequency input to the detection section 83 changes in accordance with the tuning frequency, and from the detection section 83 to each of the spiral coils 701, 702, 703 and the guide rail 20.
A signal corresponding to the averaged value of each gap between the two is output. Then, the low-pass filter 84 blocks the output of high frequency components included in the detected signal and extracts only the displacement output.

On the other hand, the sensor head 70d has magnetic bearings 60E on the left and right front parts.
, 60G, and the sensor head 70e controls the left and right rear magnetic bearings 60F, 60H, and there is no need to control the front and rear bearings, so there is no particular problem with this control, and conventionally known means can be used. be able to.

However, the sensor heads 70a, 70b, 70c are
Since the four magnetic bearings 60A, 60B, 60C, and 600 are controlled by detecting the left-right tilt and the front-back tilt, the displacement of the three locations is detected by each magnetic bearing 608, 6.
It is necessary to allocate it appropriately to 0B, 60C, and 60D.

Now, in FIG. 7, position detectors 90a, 90b,
Assuming that the detected displacement values of the position detectors 90c are a, b, and c, respectively, the left and right inclinations of the magnetic bearings 60A and 60B are calculated using the arithmetic mean value (a+b)/2 of the detected displacement values a and b of the position detectors 90a and 90b. At the same time, the magnetic bearings 60C, 600 are controlled by the displacement detection value C of the position detector 90c.
control.

Regarding the longitudinal tilt, the magnetic bearings 60A and 60C are controlled by the displacement detection value a of the position detector 90a, and the magnetic bearings 60B and 60D are controlled by the displacement detection value of the position detector 90b.

Therefore, to control the overall attitude of the upper and lower surfaces of the slider 40, the displacement detection values a, b, and c of the position detectors 90a, 90b, and 90c are added together in the arithmetic circuit 101 of FIG. Each magnetic bearing 6 is connected through the phase compensation circuit 103 and power amplifier circuit 104 of the circuit 102.
This is done by inputting into 0^, 60B, 60C, and 60 units.

By the way, each sensor head 70(a-e) consists of a single spiral coil, and as shown in FIG.
If there is a gap in the joint 20a, the slider 40 may receive a shock and hit the guide rail 20, etc., because the control is performed by a large change in inductance. On the other hand, in the configuration of the embodiment, the plurality of flat spiral coils 701, 702, 703 constituting each set of sensor heads 70 (a-e) are The spiral coils 7 of each set are arranged in parallel in the slider traveling direction at intervals that do not occur in two or more spiral coils at the same time.
Since the inductances of 01.702.703 are connected in series and averaged and a displacement signal is output according to the averaged value, it is possible to alleviate the shock that the slider 40 receives due to the gap.

That is, in the case of the example, the number of spiral coils is three, so if α is the change in inductance caused in the spiral coil due to the gap, the inductance increases at a ratio of α/3 compared to when there is only one spiral coil. Due to this change, the shock that the slider 40 receives is alleviated.

It should be noted that if the spiral coil of the above embodiment is formed into an elliptical shape that is elongated in the direction of movement of the slider, it is possible to effectively deal with the leveling out of surface unevenness and unevenness of the guide rail.

Furthermore, the means for averaging the inductance of the spiral coils is not limited to the illustrated series connection structure, but may also employ a parallel connection structure. Furthermore, the number of connected spiral coils only needs to be at least two, and the greater the number, the more effective it becomes. Furthermore, the present invention is applicable not only to those in which the guide rail is laid linearly, but also to those in which the guide rail is branched or curved.

According to the present invention, each set of sensor heads connects a plurality of flat spiral coils to the slider at intervals such that changes in inductance due to gaps between guide rail joints do not occur simultaneously in two or more spiral coils. They are arranged in parallel in the direction of travel, and the inductance of each spiral coil in each set is averaged and a displacement signal is output according to the averaged value, so even if there is a gap at the joint of the guide rail, the This has the effect of alleviating shock to the slider due to the gap.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a position detector for a magnetic levitation traveling device according to an embodiment of the present invention, FIG. 2 is a gentle sectional view of the magnetic levitation traveling device, and FIG. V-V line sectional view, 4th
Figure 5 is a front view of the sensor, Figure 5 is a partially cutaway front view of the sensor in its mounted state, Figure 6 is a perspective view showing the sensor attached to the core, Figure 7 is a block diagram of the position control device, FIG. 8 is an explanatory diagram of the operation of the spiral coil. 20...Guide rail, 21J, 21K, 21
L, 21M...Guide surface, 40...Slider,
60^, 60B. 60C, 600...Magnetic bearing for vertical guidance, 60E
, 60F, 60G, 608...Magnetic bearing for left/right direction guidance, 70a, 70b, 70c, 7
0d, 70e...Sensor head, 701.7
02.703 ... Spiral coil, 80 ... Tuning circuit, 81 ... Capacitor, 82 ... High frequency oscillation circuit, 83 ... Detection section, 84 ... Low pass filter. Patent Applicant NCH Toyo Bearing Co., Ltd. Agent Patent Attorney Takashi Ohnishi Figure 2 Figure 3

Claims (1)

[Claims] (1) In a magnetically levitated traveling device in which a slider levitates by magnetic force and travels along a guide rail, a plurality of sets of sensor heads are attached to the slider and arranged to face the guide surface of the guide rail, and the sensor heads A high-frequency oscillation circuit that drives the tuned circuit, a detection section that detects the high frequency generated in the tuned circuit, and a low-pass filter that blocks the high frequency component after detection. Each set of sensor heads has a plurality of flat spiral coils arranged side by side in the direction of movement of the slider at intervals such that changes in inductance due to gaps between guide rail joints do not occur in two or more spiral coils at the same time. 1. A position detector for a magnetic levitation traveling device, characterized in that the inductance of each spiral coil in the set is averaged and a displacement signal is output in accordance with the averaged value.